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O'Brien MW, Schwartz BD, Petterson JL, Courish MK, Shivgulam ME, Kimmerly DS. Nadir blood pressure responses to longer consecutive cardiac cycle sequences absent of sympathetic bursts are associated with popliteal endothelial-dependent dilation. Auton Neurosci 2024; 254:103193. [PMID: 38852226 DOI: 10.1016/j.autneu.2024.103193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/28/2024] [Accepted: 05/30/2024] [Indexed: 06/11/2024]
Abstract
PURPOSE The nadir pressure responses to cardiac cycles absent of muscle sympathetic nerve activity (MSNA) bursts (or non-bursts) are typically reported in studies quantifying sympathetic transduction, but the information gained by studying non-bursts is unclear. We tested the hypothesis that longer sequences of non-bursts (≥8 cardiac cycles) would be associated with a greater nadir diastolic blood pressure (DBP) and that better popliteal artery function would be associated with an augmented reduction in DBP. METHODS Resting beat-by-beat DBP (via finger photoplethysmography) and common peroneal nerve MSNA (via microneurography) were recorded in 39 healthy, adults (age 23.4 ± 5.3 years; 19 females). For each cardiac cycle absent of MSNA bursts, the mean nadir DBP (ΔDBP) during the 12 cardiac cycles following were determined, and separate analyses were conducted for ≥8 or < 8 cardiac cycle sequences. Popliteal artery endothelial-dependent (via flow-mediated dilation; FMD) and endothelial-independent vasodilation (via nitroglycerin-mediated dilation; NMD) were determined. RESULTS The nadir DBP responses to sequences ≥8 cardiac cycles were larger (-1.40 ± 1.27 mmHg) than sequences <8 (-0.38 ± 0.46 mmHg; p < 0.001). In adjusting for sex and burst frequency (14 ± 8 bursts/min), larger absolute or relative FMD (p < 0.01), but not NMD (p > 0.53) was associated with an augmented nadir DBP. This overall DBP-FMD relationship was similar in sequences ≥8 (p = 0.04-0.05), but not <8 (p > 0.72). CONCLUSION The DBP responses to non-bursts, particularly longer sequences, were inversely associated with popliteal endothelial function, but not vascular smooth muscle sensitivity. This study provides insight into the information gained by quantifying the DBP responses to cardiac cycles absent of MSNA.
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Affiliation(s)
- Myles W O'Brien
- Department of Medicine, Université de Sherbrooke, Sherbrooke, Quebec, Canada; Centre de Formation Médicale du Nouveau-Brunswick, Université de Sherbrooke, Moncton, New Brunswick, Canada.
| | - Beverly D Schwartz
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Jennifer L Petterson
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Molly K Courish
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Madeline E Shivgulam
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada.
| | - Derek S Kimmerly
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada.
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Bigalke JA, Greenlund IM, Bigalke JR, Carter JR. Actigraphy-based sleep and muscle sympathetic nerve activity in humans. Am J Physiol Regul Integr Comp Physiol 2024; 327:R145-R151. [PMID: 38842513 DOI: 10.1152/ajpregu.00113.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/07/2024]
Abstract
Short and insufficient sleep are prevalent and associated with cardiovascular disease, with the sympathetic nervous system as a suspected mediator. The purpose of the present study was to investigate the association between objective, actigraphy-based total sleep time (TST), sleep efficiency (SE), and cardiovascular and sympathetic regulation in healthy adults. We hypothesized that short TST and low SE would be associated with elevated resting blood pressure, heart rate (HR), and muscle sympathetic nerve activity (MSNA). Participants included 94 individuals [46 males, 48 females, age: 30 ± 15 yr, body mass index (BMI): 26 ± 4 kg/m2]. All participants underwent at least 7 days of at-home, wristwatch actigraphy monitoring (avg: 10 ± 3 days). Seated blood pressures were assessed using brachial blood pressure measurements, followed by a 10-minute supine autonomic testing session consisting of continuous HR (electrocardiogram), beat-by-beat blood pressure (finger plethysmograph), and MSNA (microneurography) monitoring. Partial correlations were used to determine the relationship between sleep and cardiovascular parameters while accounting for the influence of age, sex, and BMI. TST was not associated with MAP (R = -0.105, P = 0.321), HR (R = 0.093, P = 0.383), or MSNA burst frequency (BF; R = -0.168, P = 0.112) and burst incidence (BI; R = -0.162, P = 0.124). Similarly, SE was not associated with MAP (R = -0.088, P = 0.408), HR (R = -0.118, P = 0.263), MSNA BF (R = 0.038, P = 0.723), or MSNA BI (R = 0.079, P = 0.459). In contrast to recent preliminary findings, our results do not support a significant association between actigraphy-based sleep duration or efficiency and measures of resting blood pressure, heart rate, and MSNA.NEW & NOTEWORTHY The present study investigated the independent association between actigraphy-based sleep duration, efficiency, and measures of blood pressure, heart rate, and muscle sympathetic nerve activity (MSNA) in adult males and females. Contrary to our hypothesis, the findings do not support an independent association between habitual sleep and cardiovascular or sympathetic neural activity. However, these findings do not preclude a potential association between these parameters in populations with sleep disorders and/or cardiovascular disease.
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Affiliation(s)
- Jeremy A Bigalke
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
- Department of Psychology, Montana State University, Bozeman, Montana, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - Ian M Greenlund
- Department of Psychology, Montana State University, Bozeman, Montana, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Jennifer R Bigalke
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
| | - Jason R Carter
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
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Berbrier DE, Adler TE, Leone CA, Paidas MJ, Stachenfeld NS, Usselman CW. Blood pressure responses to handgrip exercise but not apnea or mental stress are enhanced in women with a recent history of preeclampsia. Am J Physiol Heart Circ Physiol 2024; 327:H140-H154. [PMID: 38700469 DOI: 10.1152/ajpheart.00020.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/29/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
Preeclampsia is a risk factor for future cardiovascular diseases. However, the mechanisms underlying this association remain unclear, limiting effective prevention strategies. Blood pressure responses to acute stimuli may reveal cardiovascular dysfunction not apparent at rest, identifying individuals at elevated cardiovascular risk. Therefore, we compared blood pressure responsiveness with acute stimuli between previously preeclamptic (PPE) women (34 ± 5 yr old, 13 ± 6 mo postpartum) and women following healthy pregnancies (Ctrl; 29 ± 3 yr old, 15 ± 4 mo postpartum). Blood pressure (finger photoplethysmography calibrated to manual sphygmomanometry-derived values; PPE: n = 12, Ctrl: n = 12) was assessed during end-expiratory apnea, mental stress, and isometric handgrip exercise protocols. Integrated muscle sympathetic nerve activity (MSNA) was assessed in a subset of participants (peroneal nerve microneurography; PPE: n = 6, Ctrl: n = 8). Across all protocols, systolic blood pressure (SBP) was higher in PPE than Ctrl (main effects of group all P < 0.05). Peak changes in SBP were stressor specific: peak increases in SBP were not different between PPE and Ctrl during apnea (8 ± 6 vs. 6 ± 5 mmHg, P = 0.32) or mental stress (9 ± 5 vs. 4 ± 7 mmHg, P = 0.06). However, peak exercise-induced increases in SBP were greater in PPE than Ctrl (11 ± 5 vs. 7 ± 7 mmHg, P = 0.04). MSNA was higher in PPE than Ctrl across all protocols (main effects of group all P < 0.05), and increases in peak MSNA were greater in PPE than Ctrl during apnea (44 ± 6 vs. 27 ± 14 burst/100 hb, P = 0.04) and exercise (25 ± 8 vs. 13 ± 11 burst/100 hb, P = 0.01) but not different between groups during mental stress (2 ± 3 vs. 0 ± 5 burst/100 hb, P = 0.41). Exaggerated pressor and sympathetic responses to certain stimuli may contribute to the elevated long-term risk for cardiovascular disease in PPE.NEW & NOTEWORTHY Women with recent histories of preeclampsia demonstrated higher systolic blood pressures across sympathoexcitatory stressors relative to controls. Peak systolic blood pressure reactivity was exacerbated in previously preeclamptic women during small muscle-mass exercises, although not during apneic or mental stress stimuli. These findings underscore the importance of assessing blood pressure control during a variety of experimental conditions in previously preeclamptic women to elucidate mechanisms that may contribute to their elevated cardiovascular disease risk.
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Affiliation(s)
- Danielle E Berbrier
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Tessa E Adler
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
- The John B. Pierce Laboratory, Yale School of Medicine, New Haven, Connecticut, United States
| | - Cheryl A Leone
- The John B. Pierce Laboratory, Yale School of Medicine, New Haven, Connecticut, United States
| | - Michael J Paidas
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, United States
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Nina S Stachenfeld
- The John B. Pierce Laboratory, Yale School of Medicine, New Haven, Connecticut, United States
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, Connecticut, United States
| | - Charlotte W Usselman
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
- The John B. Pierce Laboratory, Yale School of Medicine, New Haven, Connecticut, United States
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Edwards JJ, Coleman DA, Ritti-Dias RM, Farah BQ, Stensel DJ, Lucas SJE, Millar PJ, Gordon BDH, Cornelissen V, Smart NA, Carlson DJ, McGowan C, Swaine I, Pescatello LS, Howden R, Bruce-Low S, Farmer CKT, Leeson P, Sharma R, O'Driscoll JM. Isometric Exercise Training and Arterial Hypertension: An Updated Review. Sports Med 2024; 54:1459-1497. [PMID: 38762832 PMCID: PMC11239608 DOI: 10.1007/s40279-024-02036-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2024] [Indexed: 05/20/2024]
Abstract
Hypertension is recognised as a leading attributable risk factor for cardiovascular disease and premature mortality. Global initiatives towards the prevention and treatment of arterial hypertension are centred around non-pharmacological lifestyle modification. Exercise recommendations differ between professional and scientific organisations, but are generally unanimous on the primary role of traditional aerobic and dynamic resistance exercise. In recent years, isometric exercise training (IET) has emerged as an effective novel exercise intervention with consistent evidence of reductions in blood pressure (BP) superior to that reported from traditional guideline-recommended exercise modes. Despite a wealth of emerging new data and endorsement by select governing bodies, IET remains underutilised and is not widely prescribed in clinical practice. This expert-informed review critically examines the role of IET as a potential adjuvant tool in the future clinical management of BP. We explore the efficacy, prescription protocols, evidence quality and certainty, acute cardiovascular stimulus, and physiological mechanisms underpinning its anti-hypertensive effects. We end the review with take-home suggestions regarding the direction of future IET research.
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Affiliation(s)
- Jamie J Edwards
- School of Psychology and Life Sciences, Canterbury Christ Church University, Kent, CT1 1QU, UK
| | - Damian A Coleman
- School of Psychology and Life Sciences, Canterbury Christ Church University, Kent, CT1 1QU, UK
| | - Raphael M Ritti-Dias
- Graduate Program in Rehabilitation Sciences, University Nove de Julho, São Paulo, Brazil
| | - Breno Q Farah
- Department of Physical Education, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - David J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
- NIHR Leicester Biomedical Research Centre, University Hospitals of Leicester NHS Trust and the University of Leicester, Leicester, UK
- Faculty of Sport Sciences, Waseda University, Tokyo, Japan
- Department of Sports Science and Physical Education, The Chinese University of Hong Kong, Hong Kong, China
| | - Sam J E Lucas
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Philip J Millar
- Human Cardiovascular Physiology Laboratory, Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON, Canada
| | - Ben D H Gordon
- Department of Health and Human Development, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Neil A Smart
- School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - Debra J Carlson
- School of Health, Medical and Applied Sciences, CQ University, North Rockhampton, QLD, Australia
| | - Cheri McGowan
- Department of Kinesiology, University of Windsor, Windsor, ON, Canada
| | - Ian Swaine
- Sport Science, University of Greenwich, London, UK
| | - Linda S Pescatello
- Department of Kinesiology, University of Connecticut, Storrs, CT, 06269, USA
| | - Reuben Howden
- Department of Applied Physiology, Health and Clinical Sciences, UNC Charlotte, Charlotte, NC, 28223, USA
| | - Stewart Bruce-Low
- Department of Applied Sport and Exercise Science, University of East London, London, UK
| | | | - Paul Leeson
- Oxford Clinical Cardiovascular Research Facility, Department of Cardiovascular Medicine, University of Oxford, Oxford, UK
| | - Rajan Sharma
- Department of Cardiology, St George's University Hospitals NHS Foundation Trust, Blackshaw Road, Tooting, London, SW17 0QT, UK
| | - Jamie M O'Driscoll
- School of Psychology and Life Sciences, Canterbury Christ Church University, Kent, CT1 1QU, UK.
- Department of Cardiology, St George's University Hospitals NHS Foundation Trust, Blackshaw Road, Tooting, London, SW17 0QT, UK.
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Jarrard CP, Watso JC, Atkins WC, McKenna ZJ, Foster J, Huang M, Belval LN, Crandall CG. Sex Differences in Sympathetic Responses to Lower-Body Negative Pressure. Med Sci Sports Exerc 2024; 56:1056-1065. [PMID: 38233995 PMCID: PMC11187698 DOI: 10.1249/mss.0000000000003392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
INTRODUCTION Trauma-induced hemorrhage is a leading cause of death in prehospital settings. Experimental data demonstrate that females have a lower tolerance to simulated hemorrhage (i.e., central hypovolemia). However, the mechanism(s) underpinning these responses are unknown. Therefore, this study aimed to compare autonomic cardiovascular responses during central hypovolemia between the sexes. We hypothesized that females would have a lower tolerance and smaller increase in muscle sympathetic nerve activity (MSNA) to simulated hemorrhage. METHODS Data from 17 females and 19 males, aged 19-45 yr, were retrospectively analyzed. Participants completed a progressive lower-body negative pressure (LBNP) protocol to presyncope to simulate hemorrhagic tolerance with continuous measures of MSNA and beat-to-beat hemodynamic variables. We compared responses at baseline, at two LBNP stages (-40 and -50 mmHg), and at immediately before presyncope. In addition, we compared responses at relative percentages (33%, 66%, and 100%) of hemorrhagic tolerance, calculated via the cumulative stress index (i.e., the sum of the product of time and pressure at each LBNP stage). RESULTS Females had lower tolerance to central hypovolemia (female: 561 ± 309 vs male: 894 ± 304 min·mmHg [time·LBNP]; P = 0.003). At LBNP -40 and -50 mmHg, females had lower diastolic blood pressures (main effect of sex: P = 0.010). For the relative LBNP analysis, females exhibited lower MSNA burst frequency (main effect of sex: P = 0.016) accompanied by a lower total vascular conductance (sex: P = 0.028; main effect of sex). CONCLUSIONS Females have a lower tolerance to central hypovolemia, which was accompanied by lower diastolic blood pressure at -40 and -50 mmHg LBNP. Notably, females had attenuated MSNA responses when assessed as relative LBNP tolerance time.
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Affiliation(s)
- Caitlin P. Jarrard
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Applied Clinical Research Department, University of Texas Southwestern Medical Center, Dallas TX
| | - Joseph C. Watso
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Applied Clinical Research Department, University of Texas Southwestern Medical Center, Dallas TX
- College of Health and Human Sciences, Florida State University, Tallahassee, FL
| | - Whitley C. Atkins
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Zachary J. McKenna
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
| | - Josh Foster
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences and Medicine, Kings College London, London, UNITED KINGDOM
| | - Mu Huang
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Office of Science, Medicine, and Health, American Heart Association, Dallas, TX
| | - Luke N. Belval
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
| | - Craig G. Crandall
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX
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Athaide CE, Robertson AD, Devries MC, Au JS. Seated Elliptical Exercise, But Not Periodic Standing, Alleviates Sitting-Induced Changes to Arterial Wave Reflections. Med Sci Sports Exerc 2024; 56:953-962. [PMID: 38181209 DOI: 10.1249/mss.0000000000003367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2024]
Abstract
PURPOSE Sedentary behavior may contribute to increased central wave reflection due to associated peripheral vasoconstriction, yet its impact on central hemodynamics and the mitigating effects of interventional strategies have not been thoroughly investigated. We tested whether standing or seated elliptical breaks alleviate the deleterious effects of prolonged sitting on central wave reflections. METHODS Eighteen healthy adults (9 9 females, 25 ± 3 yr) completed three 3-h protocols on separate days: uninterrupted sitting, sitting with periodic standing, and sitting with periodic seated elliptical activity. Central wave reflection, central pulse wave velocity, and lower-limb pulse wave velocity were measured before and after each intervention. RESULTS Central relative wave reflection magnitude (RM) increased during sitting (0.31 ± 0.05 to 0.35 ± 0.05; P < 0.01) but did not change after standing (0.30 ± 0.05 to 0.32 ± 0.04; P = 0.19) or elliptical protocols (0.30 ± 0.05 to 0.30 ± 0.04; P > 0.99). The change in RM during prolonged sitting (ΔRM) was attenuated with elliptical activity (0.04 ± 0.05 vs 0.00 ± 0.03; P = 0.02) but not with periodic standing (0.04 ± 0.04 vs 0.02 ± 0.05; P = 0.54). In addition, augmentation index and central pulse wave velocity increased after sitting (both P < 0.01) and periodic standing (both P < 0.01) but were unchanged after elliptical activity. Lower limb pulse wave velocity did not change after sitting ( P = 0.73) or standing ( P = 0.21) but did decrease after elliptical activity ( P = 0.03). CONCLUSIONS Prolonged sitting without interruptions increased central wave reflection, whereas elliptical but not standing interruptions were able to ameliorate multiple sitting-induced vascular consequences. More work is required to examine the long-term effectiveness of interruption strategies, as well as the optimal type, frequency, and duration for reducing vascular risk associated with sedentary behaviors.
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Affiliation(s)
- Chloe E Athaide
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, CANADA
| | | | - Michaela C Devries
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, CANADA
| | - Jason S Au
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, ON, CANADA
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Desai SA, Mirza UA, Mueller PJ. Influence of sex and sedentary conditions on sympathetic burst characteristics in prepubertal, postpubertal, and young adult rats. J Appl Physiol (1985) 2024; 136:1170-1181. [PMID: 38511214 DOI: 10.1152/japplphysiol.00649.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 03/07/2024] [Accepted: 03/15/2024] [Indexed: 03/22/2024] Open
Abstract
Recent evidence indicates that sex-based differences in cardiovascular disease (CVD) begin early in life, particularly when associated with risk factors such as a sedentary lifestyle. CVD is associated with elevated sympathetic nerve activity (SNA), quantified as increased SNA burst activity in humans. Whether burst characteristics are influenced by sex or sedentary conditions at younger ages is unknown. The purpose of our study is to compare SNA bursts in active and sedentary female and male rats at ages including prepuberty and young adulthood. We hypothesized that burst characteristics and blood pressure are higher under sedentary conditions and lower in female rats compared with males. We analyzed splanchnic SNA (SpSNA) recordings from Inactin-anesthetized male and female rats at 4-, 8-, and 16-wk of age. Physically active and sedentary rats were each housed in separate, environmentally controlled chambers where physically active rats had free access to an in-cage running wheel. Sympathetic bursts were obtained by rectifying and integrating the raw SpSNA signal. Burst frequency, burst height, and burst width were calculated using the Peak Parameters extension in LabChart. Our results showed that sedentary conditions produced a greater burst width in 8- and 16-wk-old rats compared with 4-wk-old rats in both males and females (P < 0.001 for both). Burst frequency and incidence were both higher in 16-wk-old males compared with 16-wk-old females (P < 0.001 for both). Our results suggest that there are sedentary lifestyle- and sex-related mechanisms that impact sympathetic regulation of blood pressure at ages that range from prepuberty into young adulthood.NEW & NOTEWORTHY The mechanisms of decreased incidence of cardiovascular disease (CVD) in reproductive-age women compared with age-matched men are unknown. The strong association between elevated sympathetic activity and CVD led us to characterize splanchnic sympathetic bursts in female and male rats. Prepubescent males and females exhibited narrower sympathetic bursts, whereas young adult males had higher resting burst frequency compared with age-matched females. Sex-based regulation of sympathetic activity suggests a need for sex-dependent therapeutic strategies to combat CVD.
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Affiliation(s)
- Shivansh A Desai
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Umme Aiman Mirza
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Patrick J Mueller
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States
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8
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Zanuzzi MG, Jeong J, DaCosta DR, Park J. Sex differences in sympathetic activity and pulse wave velocity in adults with chronic kidney disease. Am J Physiol Renal Physiol 2024; 326:F661-F668. [PMID: 38385174 PMCID: PMC11208017 DOI: 10.1152/ajprenal.00308.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/14/2024] [Accepted: 02/14/2024] [Indexed: 02/23/2024] Open
Abstract
Chronic kidney disease (CKD) is characterized by sympathetic nervous system (SNS) overactivity that contributes to increased vascular stiffness and cardiovascular risk. Although it is well established that SNS activity and vascular stiffness are substantially elevated in CKD, whether sex differences in autonomic and vascular function exist in CKD remains unknown. We tested the hypothesis that compared with females, males with CKD have higher baseline sympathetic activity that is related to increased arterial stiffness. One hundred twenty-nine participants (96 males and 33 females) with CKD stages III and IV were recruited and enrolled. During two separate study visits, vascular stiffness was assessed by measuring carotid-to-femoral pulse wave velocity (cfPWV), and resting muscle sympathetic nerve activity (MSNA) was measured by microneurography. Males with CKD had higher resting MSNA compared with females with CKD (68 ± 16 vs. 55 ± 14 bursts/100 heart beats, P = 0.005), whereas there was no difference in cfPWV between the groups (P = 0.248). Resting MSNA was not associated with cfPWV in both males and females. In conclusion, males with CKD have higher resting sympathetic activity compared with females with CKD. However, there was no difference in vascular stiffness between the sexes. There was no correlation between resting MSNA and cfPWV, suggesting that non-neural mechanisms may play a greater role in the progression of vascular stiffness in CKD, particularly in females.NEW & NOTEWORTHY Males with chronic kidney disease (CKD) have higher resting muscle sympathetic nerve activity (MSNA) compared with females. There was no correlation between MSNA and carotid-to-femoral pulse wave velocity (cfPWV), suggesting that non-neural mechanisms may play a greater role in the progression of vascular stiffness in CKD. Sex differences in SNS activity may play a mechanistic role in observations from epidemiological studies suggesting greater cardiovascular risk in males compared with females with CKD.
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Affiliation(s)
- Matias G Zanuzzi
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Jinhee Jeong
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Dana R DaCosta
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
| | - Jeanie Park
- Division of Renal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, United States
- Department of Veterans Affairs Health Care System, Research Service Line, Decatur, Georgia, United States
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9
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Takeda R, Hissen SL, Akins JD, Washio T, Hearon CM, MacNamara JP, Sarma S, Levine BD, Fadel PJ, Fu Q. Sympathetic Neural Control at Rest and During the Cold Pressor Test in Patients With Heart Failure With Preserved Ejection Fraction. Hypertension 2024; 81:917-926. [PMID: 38385250 PMCID: PMC10954398 DOI: 10.1161/hypertensionaha.123.21918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 02/06/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND We tested the hypothesis that patients with heart failure with preserved ejection fraction (HFpEF) would have greater muscle sympathetic nerve activity (MSNA) at rest and sympathetic reactivity during a cold pressor test compared with non-heart failure controls. Further, given the importance of the baroreflex modulation of MSNA in the control of blood pressure (BP), we hypothesized that patients with HFpEF would exhibit a reduced sympathetic baroreflex sensitivity. METHODS Twenty-eight patients with HFpEF and 44 matched controls (mean±SD: 71±8 versus 70±7 years; 9 men/19 women versus 16 men/28 women) were studied. BP, heart rate, and MSNA (microneurography) were measured during 6 to 10 minutes of supine rest and the 2-minute cold pressor test. Spontaneous sympathetic baroreflex sensitivity was assessed during supine rest. RESULTS Patients with HFpEF had higher resting MSNA burst frequency (39±14 versus 31±12 bursts/min; P=0.020) and lower sympathetic baroreflex sensitivity (-2.83±0.76 versus -3.57±1.19 bursts/100 heartbeats/mm Hg; P=0.019) than controls, but burst incidence was not different between groups (56±19 versus 50±20 bursts/100 heartbeats; P=0.179). During the cold pressor test, increases in MSNA indices did not differ between groups (P=0.135-0.998), but patients had a smaller increase in diastolic BP (Δ4±6 versus Δ14±11 mm Hg; P<0.001) compared with controls. CONCLUSIONS Despite augmented resting MSNA burst frequency, burst incidence was not significantly different between groups, and sympathetic baroreflex sensitivity was reduced in patients with HFpEF. Furthermore, patients had preserved sympathetic reactivity but attenuated diastolic BP responses during the cold pressor test. These data suggest that, during physiological stress, sympathetic reactivity is intact, but the peripheral pathway for sympathetic vasoconstriction may be impaired in HFpEF.
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Affiliation(s)
- Ryosuke Takeda
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sarah L. Hissen
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - John D. Akins
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Takuro Washio
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Christopher M. Hearon
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - James P. MacNamara
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Satyam Sarma
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Benjamin D. Levine
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Paul J. Fadel
- University of Texas at Arlington, Arlington, Texas, USA
| | - Qi Fu
- Institute for Exercise and Environmental Medicine at Texas Health Presbyterian Hospital Dallas
- University of Texas Southwestern Medical Center, Dallas, Texas, USA
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10
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Nardone M, Foster M, O'Brien MW, Coovadia Y, Xie S, Usselman CW, Kimmerly DS, Taylor CE, Millar PJ. Sympathetic determinants of resting blood pressure in males and females. Am J Physiol Heart Circ Physiol 2024; 326:H612-H622. [PMID: 38214907 DOI: 10.1152/ajpheart.00497.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/08/2024] [Accepted: 01/08/2024] [Indexed: 01/13/2024]
Abstract
Discharge of postganglionic muscle sympathetic nerve activity (MSNA) is related poorly to blood pressure (BP) in adults. Whether neural measurements beyond the prevailing level of MSNA can account for interindividual differences in BP remains unclear. The current study sought to evaluate the relative contributions of sympathetic-BP transduction and sympathetic baroreflex gain on resting BP in young adults. Data were analyzed from 191 (77 females) young adults (18-39 years) who underwent continuous measurement of beat-to-beat BP (finger photoplethysmography), heart rate (electrocardiography), and fibular nerve MSNA (microneurography). Linear regression analyses were computed to determine associations between sympathetic-BP transduction (signal-averaging) or sympathetic baroreflex gain (threshold technique) and resting BP, before and after controlling for age, body mass index, and MSNA burst frequency. K-mean clustering was used to explore sympathetic phenotypes of BP control and consequential influence on resting BP. Sympathetic-BP transduction was unrelated to BP in males or females (both R2 < 0.01; P > 0.67). Sympathetic baroreflex gain was positively associated with BP in males (R2 = 0.09, P < 0.01), but not in females (R2 < 0.01; P = 0.80), before and after controlling for age, body mass index, and MSNA burst frequency. K-means clustering identified a subset of participants with average resting MSNA, yet lower sympathetic-BP transduction and lower sympathetic baroreflex gain. This distinct subgroup presented with elevated BP in males (P < 0.02), but not in females (P = 0.10). Sympathetic-BP transduction is unrelated to resting BP, while the association between sympathetic baroreflex gain and resting BP in males reveals important sex differences in the sympathetic determination of resting BP.NEW & NOTEWORTHY In a sample of 191 normotensive young adults, we confirm that resting muscle sympathetic nerve activity is a poor predictor of resting blood pressure and now demonstrate that sympathetic baroreflex gain is associated with resting blood pressure in males but not females. In contrast, signal-averaged measures of sympathetic-blood pressure transduction are unrelated to resting blood pressure. These findings highlight sex differences in the neural regulation of blood pressure.
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Affiliation(s)
- Massimo Nardone
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Monique Foster
- School of Health Sciences, Western Sydney University, Sydney, New South Wales, Australia
| | - Myles W O'Brien
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
- School of Physiotherapy (Faculty of Health) and Division of Geriatric Medicine (Faculty of Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yasmine Coovadia
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Shengkun Xie
- Global Management Studies, Ted Rogers School of Management, Toronto Metropolitan University, Toronto, Ontario, Canada
| | - Charlotte W Usselman
- Cardiovascular Health and Autonomic Regulation Laboratory, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Derek S Kimmerly
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Chloe E Taylor
- School of Health Sciences, Western Sydney University, Sydney, New South Wales, Australia
| | - Philip J Millar
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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11
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Bigalke JA, Young BE, Cleveland EL, Fadel PJ, Carter JR. Aging and sympathetic transduction to blood pressure in humans: methodological and physiological considerations. Am J Physiol Heart Circ Physiol 2024; 326:H148-H157. [PMID: 37921667 PMCID: PMC11213475 DOI: 10.1152/ajpheart.00359.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 11/04/2023]
Abstract
Recent reports suggest that quantification of signal-averaged sympathetic transduction is influenced by resting muscle sympathetic nerve activity (MSNA) and burst occurrence relative to the average mean arterial pressure (MAP). Herein, we asked how these findings may influence age-related reductions in sympathetic transduction. Beat-to-beat blood pressure and MSNA were recorded during 5 min of rest in 27 younger (13 females: age, 25 ± 5 yr; BMI, 25 ± 4 kg/m2) and 26 older (15 females: age, 59 ± 5 yr; BMI, 26 ± 4 kg/m2) healthy adults. All MSNA bursts were signal averaged together. Beat-to-beat MAP values were then split into low (T1), middle (T2), and high (T3) tertiles, and signal-averaged transduction was calculated within each tertile. Resting MSNA was higher in older adults and MAP was similar between groups. Older adults exhibited blunted overall MAP transduction (younger, Δ1.5 ± 0.6 vs. older, Δ0.9 ± 0.7 mmHg; P = 0.005), which was irrespective of relation to prevailing MAP. A greater proportion of bursts occurred above the average MAP in older adults (P < 0.001), and a larger proportion of these bursts were associated with depressor responses (P = 0.005). Nonetheless, assessment of bursts above the average MAP associated with pressor responses revealed similar age-associated reductions in transduction (younger, Δ2.6 ± 1.6 vs. older, Δ1.7 ± 0.8 mmHg; P = 0.016). These findings indicate an age-related increase in burst occurrence above the average resting MAP, which alone does not explain blunted transduction, thereby supporting the physiological underpinnings of age-related decrements in sympathetic transduction to blood pressure.NEW & NOTEWORTHY The current study demonstrated that aging is associated with a greater prevalence of sympathetic bursts occurring above the average blood pressure, which offers both methodologically and physiologically relevant information regarding aging and sympathetic control of blood pressure. These data support age-related reductions in sympathetic transduction via a reduced pressor response to sympathetic bursts irrespective of the prevailing absolute blood pressure value, along with increases in sympathetic outflow necessary to maintain blood pressure.
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Affiliation(s)
- Jeremy A Bigalke
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
- Department of Psychology, Montana State University, Bozeman, Montana, United States
| | - Benjamin E Young
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
- Department of Applied Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Emily L Cleveland
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, Montana, United States
| | - Paul J Fadel
- Department of Kinesiology, University of Texas at Arlington, Arlington, Texas, United States
| | - Jason R Carter
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
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12
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Grotle AK, Langlo JV, Holsbrekken E, Stone AJ, Tanaka H, Fadel PJ. Age-related alterations in the cardiovascular responses to acute exercise in males and females: role of the exercise pressor reflex. Front Physiol 2023; 14:1287392. [PMID: 38028783 PMCID: PMC10652405 DOI: 10.3389/fphys.2023.1287392] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/09/2023] [Indexed: 12/01/2023] Open
Abstract
Autonomic adjustments of the cardiovascular system are critical for initiating and sustaining exercise by facilitating the redistribution of blood flow and oxygen delivery to meet the metabolic demands of the active skeletal muscle. Afferent feedback from active skeletal muscles evokes reflex increases in sympathetic nerve activity and blood pressure (BP) (i.e., exercise pressor reflex) and contributes importantly to these primary neurovascular adjustments to exercise. When altered, this reflex contributes significantly to the exaggerated sympathetic and BP response to exercise observed in many cardiovascular-related diseases, highlighting the importance of examining the reflex and its underlying mechanism(s). A leading risk factor for the pathogenesis of cardiovascular disease in both males and females is aging. Although regular exercise is an effective strategy for mitigating the health burden of aging, older adults face a greater risk of experiencing an exaggerated cardiovascular response to exercise. However, the role of aging in mediating the exercise pressor reflex remains highly controversial, as conflicting findings have been reported. This review aims to provide a brief overview of the current understanding of the influence of aging on cardiovascular responses to exercise, focusing on the role of the exercise pressor reflex and proposing future directions for research. We reason that this review will serve as a resource for health professionals and researchers to stimulate a renewed interest in this critical area.
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Affiliation(s)
- A. K. Grotle
- Department of Sports, Food and Natural Science, Western Norway University of Applied Sciences, Bergen, Norway
| | - J. V. Langlo
- Department of Sports, Food and Natural Science, Western Norway University of Applied Sciences, Bergen, Norway
| | - E. Holsbrekken
- Department of Sports, Food and Natural Science, Western Norway University of Applied Sciences, Bergen, Norway
| | - A. J. Stone
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States
| | - H. Tanaka
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States
| | - P. J. Fadel
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, United States
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13
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Triposkiadis F, Briasoulis A, Sarafidis P, Magouliotis D, Athanasiou T, Paraskevaidis I, Skoularigis J, Xanthopoulos A. The Sympathetic Nervous System in Hypertensive Heart Failure with Preserved LVEF. J Clin Med 2023; 12:6486. [PMID: 37892623 PMCID: PMC10607346 DOI: 10.3390/jcm12206486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/09/2023] [Accepted: 10/11/2023] [Indexed: 10/29/2023] Open
Abstract
The neurohormonal model of heart failure (HF) pathogenesis states that a reduction in cardiac output caused by cardiac injury results in sympathetic nervous system (SNS) activation, that is adaptive in the short-term and maladaptive in the long-term. This model has proved extremely valid and has been applied in HF with a reduced left ventricular (LV) ejection fraction (LVEF). In contrast, it has been undermined in HF with preserved LVEF (HFpEF), which is due to hypertension (HTN) in the vast majority of the cases. Erroneously, HTN, which is the leading cause of cardiovascular disease and premature death worldwide and is present in more than 90% of HF patients, is tightly linked with SNS overactivity. In this paper we provide a contemporary overview of the contribution of SNS overactivity to the development and progression of hypertensive HF (HHF) as well as the clinical implications resulting from therapeutic interventions modifying SNS activity. Throughout the manuscript the terms HHF with preserved LVEF and HfpEF will be used interchangeably, considering that the findings in most HFpEF studies are driven by HTN.
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Affiliation(s)
| | - Alexandros Briasoulis
- Department of Therapeutics, Heart Failure and Cardio-Oncology Clinic, National and Kapodistrian University of Athens, 115 27 Athens, Greece;
| | - Pantelis Sarafidis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece;
| | - Dimitrios Magouliotis
- Unit of Quality Improvement, Department of Cardiothoracic Surgery, University of Thessaly, 411 10 Biopolis, Greece;
| | - Thanos Athanasiou
- Department of Surgery and Cancer, Imperial College London, St Mary’s Hospital, London W2 1NY, UK;
| | | | - John Skoularigis
- Department of Cardiology, University Hospital of Larissa, 411 10 Larissa, Greece;
| | - Andrew Xanthopoulos
- Department of Cardiology, University Hospital of Larissa, 411 10 Larissa, Greece;
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14
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D'Souza AW, Hissen SL, Manabe K, Takeda R, Washio T, Coombs GB, Sanchez B, Fu Q, Shoemaker JK. Age- and sex-related differences in sympathetic vascular transduction and neurohemodynamic balance in humans. Am J Physiol Heart Circ Physiol 2023; 325:H917-H932. [PMID: 37594483 DOI: 10.1152/ajpheart.00301.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 08/19/2023]
Abstract
Bursts of muscle sympathetic nerve activity (MSNA) and the ensuing vasoconstriction are pivotal determinants of beat-by-beat blood pressure regulation. Although age and sex impact blood pressure regulation, how these factors affect the central and peripheral arcs of the baroreflex remains unclear. In 27 young [25 (SD 3) yr] males (YM; n = 14) and females (YF; n = 13) and 23 older [71 (SD 5) yr] males (OM; n = 11) and females (OF; n = 12), femoral artery blood flow, blood pressure, and MSNA were recorded for 10 min of supine rest. Sympathetic baroreflex sensitivity (i.e., central arc) was quantified as the relationship between diastolic blood pressure and MSNA burst incidence. Signal averaging was used to determine sympathetic vascular transduction into leg vascular conductance (LVC) for 12 cardiac cycles following MSNA bursts (i.e., peripheral arc). Older adults demonstrated attenuated sympathetic transduction into LVC (both P < 0.001) following MSNA bursts, and smaller increases in sympathetic transduction as a function of MSNA burst size and firing pattern compared with young adults (range, P = 0.004-0.032). YM (r2 = 0.36; P = 0.032) and OM (r2 = 0.51; P = 0.014) exhibited an inverse relationship between the central and peripheral arcs of the baroreflex, whereas females did not (YF, r2 = 0.03, P = 0.621; OF, r2 = 0.06, P = 0.445). MSNA burst incidence was inversely related to sympathetic transduction in YM and OF (range, P = 0.03-0.046) but not in YF or OM (range, P = 0.360-0.603). These data indicate that age is associated with attenuated sympathetic vascular transduction, whereas age- and sex-specific changes are present in the relationship between the central and peripheral arcs of the baroreflex regulation of blood pressure.NEW & NOTEWORTHY Sympathetic vascular transduction is attenuated in older compared with young adults, regardless of biological sex. Males, but not females (regardless of age), demonstrate an inverse relationship between central (sympathetic baroreflex sensitivity) and peripheral (sympathetic vascular transduction) components of the baroreflex arc. Young males and older females exhibit an inverse relationship between resting sympathetic outflow and sympathetic vascular transduction. Our results indicate that age and sex exert independent and interactive effects on sympathetic vascular transduction and sympathetic neurohemodynamic balance in humans.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Sarah L Hissen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Kazumasa Manabe
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Ryosuke Takeda
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Takuro Washio
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Geoff B Coombs
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Belinda Sanchez
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, United States
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, United States
| | - J Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
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15
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Adams ZH, Barnes JN, Lord RN. Causes and consequences of sympathoexcitation across the lifespan: Physiological or pathological? Exp Physiol 2023; 108:1235-1237. [PMID: 37712577 PMCID: PMC10988441 DOI: 10.1113/ep091217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 09/05/2023] [Indexed: 09/16/2023]
Affiliation(s)
- Zoe H. Adams
- Cardiff School of Sport and Health SciencesCardiff Metropolitan UniversityCardiffUK
| | - Jill N. Barnes
- Bruno Balke Biodynamics Laboratory, Department of KinesiologyUniversity of Wisconsin MadisonMadisonWIUSA
| | - Rachel N. Lord
- Cardiff School of Sport and Health SciencesCardiff Metropolitan UniversityCardiffUK
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16
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Notarius CF, Badrov MB, Tobushi T, Keir DA, Keys E, Floras JS. Cardiovascular reflex contributions to sympathetic inhibition during low intensity dynamic leg exercise in healthy middle-age. Physiol Rep 2023; 11:e15821. [PMID: 37701968 PMCID: PMC10498156 DOI: 10.14814/phy2.15821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 08/22/2023] [Indexed: 09/14/2023] Open
Abstract
Aging augments resting muscle sympathetic nerve activity (MSNA) and sympatho-inhibition during mild dynamic 1-leg exercise. To elucidate which reflexes elicit exercise-induced inhibition, we recruited 19 (9 men) healthy volunteers (mean age 56 ± 9 SD years), assessed their peak oxygen uptake (VO2peak ), and, on another day, measured heart rate (HR), blood pressure (BP) and MSNA (microneurography) at rest and during 1-leg cycling (2 min each at 0 load and 30%-40% VO2peak ), 3 times: (1) seated +2 min of postexercise circulatory occlusion (PECO) (elicit muscle metaboreflex); (2) supine (stimulate cardiopulmonary baroreflexes);and (3) seated, breathing 32% oxygen (suppress peripheral chemoreceptor reflex). While seated, MSNA decreased similarly during mild and moderate exercise (p < 0.001) with no increase during PECO (p = 0.44). Supine posture lowered resting MSNA (main effect p = 0.01) BP and HR. MSNA fell further (p = 0.04) along with diastolic BP and HR during mild, not moderate, supine cycling. Hyperoxia attenuated resting (main effect p = 0.01), but not exercise MSNA. In healthy middle-age, the cardiopulmonary baroreflex and arterial chemoreflex modulate resting MSNA, but contrary to previous observations in young subjects, without counter-regulatory offset by the sympatho-excitatory metaboreflex, resulting in an augmented sympatho-inhibitory response to mild dynamic leg exercise.
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Affiliation(s)
- Catherine F. Notarius
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
- Faculty of Kinesiology and Physical EducationUniversity of TorontoTorontoOntarioCanada
| | - Mark B. Badrov
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
| | - Tomoyuki Tobushi
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
| | - Daniel A. Keir
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
- School of KinesiologyThe University of Western OntarioLondonOntarioCanada
| | - Evan Keys
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
| | - John S. Floras
- University Health Network and Sinai Health Division of CardiologyToronto General Research InstituteTorontoOntarioCanada
- Department of MedicineUniversity of TorontoTorontoOntarioCanada
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17
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Bock JM, Greenlund IM, Somers VK, Baker SE. Sex Differences in Neurovascular Control: Implications for Obstructive Sleep Apnea. Int J Mol Sci 2023; 24:13094. [PMID: 37685900 PMCID: PMC10487948 DOI: 10.3390/ijms241713094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 09/10/2023] Open
Abstract
Patients with obstructive sleep apnea (OSA) have a heightened risk of developing cardiovascular diseases, namely hypertension. While seminal evidence indicates a causal role for sympathetic nerve activity in the hypertensive phenotype commonly observed in patients with OSA, no studies have investigated potential sex differences in the sympathetic regulation of blood pressure in this population. Supporting this exploration are large-scale observational data, as well as controlled interventional studies in healthy adults, indicating that sleep disruption increases blood pressure to a greater extent in females relative to males. Furthermore, females with severe OSA demonstrate a more pronounced hypoxic burden (i.e., disease severity) during rapid eye movement sleep when sympathetic nerve activity is greatest. These findings would suggest that females are at greater risk for the hemodynamic consequences of OSA and related sleep disruption. Accordingly, the purpose of this review is three-fold: (1) to review the literature linking sympathetic nerve activity to hypertension in OSA, (2) to highlight recent experimental data supporting the hypothesis of sex differences in the regulation of sympathetic nerve activity in OSA, and (3) to discuss the potential sex differences in peripheral adrenergic signaling that may contribute to, or offset, cardiovascular risk in patients with OSA.
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Affiliation(s)
- Joshua M. Bock
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Ian M. Greenlund
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Virend K. Somers
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN 55901, USA; (J.M.B.)
| | - Sarah E. Baker
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN 55901, USA
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18
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D'Souza AW, Takeda R, Manabe K, Hissen SL, Washio T, Coombs GB, Sanchez B, Fu Q, Shoemaker JK. The interactive effects of age and sex on the neuro-cardiovascular responses during fatiguing rhythmic handgrip exercise. J Physiol 2023; 601:2877-2898. [PMID: 37083007 DOI: 10.1113/jp284517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 03/30/2023] [Indexed: 04/22/2023] Open
Abstract
The impact of age on exercise pressor responses is equivocal, likely because of sex-specific neuro-cardiovascular changes with age. However, assessments of the interactive effects of age and sex on muscle sympathetic nerve activity (MSNA) responses to exercise are lacking. We tested the hypothesis that older females would exhibit exaggerated increases in blood pressure (BP) and MSNA discharge patterns during handgrip exercise compared with similarly aged males and young adults. Twenty-five young (25 (2) years; mean (SD)) males (YM; n = 12) and females (YF; n = 13) and 23 older (71 (5) years) males (OM; n = 11) and females (OF; n = 12) underwent assessments of BP, total peripheral resistance (TPR; Modelflow) and MSNA action potential (AP) discharge patterns (microneurography) during incremental rhythmic handgrip exercise and post-exercise circulatory occlusion (PECO). OM demonstrated larger ∆BP and ∆TPR from baseline than YM (both P < 0.001) despite smaller increases in ∆APs/burst (OM: 0.4 (3) vs. YM: 5 (3) spikes/burst, P < 0.001) and ∆AP clusters/burst (OM: 0.1 (1) vs. YM: 1.8 (1) clusters/burst, P < 0.001) during exercise. Testosterone was lower in OM than YM (P < 0.001) and was inversely related to ∆BP but positively related to ∆AP clusters/burst in males (both P = 0.03). Conversely, YF and OF demonstrated similar ∆BP and ∆AP discharge during exercise (range: P = 0.75-0.96). Age and sex did not impact haemodynamics or AP discharge during PECO (range: P = 0.08-0.94). Altogether, age-related changes in neuro-cardiovascular reactivity exist in males but not females during fatiguing exercise and seem to be related to testosterone. This sex-specific impact of age underscores the importance of considering biological sex when assessing age-related changes in neuro-cardiovascular control during exercise. KEY POINTS: Older males have the largest increase in blood pressure despite having the smallest increases in sympathetic vasomotor outflow during rhythmic handgrip exercise. Young males demonstrate greater increases in sympathetic action potential (AP) discharge compared with young females during rhythmic handgrip exercise. Older adults (regardless of sex) demonstrate smaller increases in muscle sympathetic nerve activity (MSNA) burst amplitude and total AP clusters compared with young adults during exercise, as well as smaller increases in integrated MSNA burst frequency, incidence and total MSNA activity during post-exercise circulatory occlusion (i.e. independent effect of age). Males, but not females (regardless of age), reflexively modify AP conduction velocity during exercise. Our results indicate that age and sex independently and interactively impact the neural and cardiovascular homeostatic adjustments to fatiguing small muscle mass exercise.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Ryosuke Takeda
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kazumasa Manabe
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Sarah L Hissen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Takuro Washio
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Geoff B Coombs
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Belinda Sanchez
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - J Kevin Shoemaker
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
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19
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Hotta H, Iimura K, Watanabe N, Suzuki H, Sugie M, Shigemoto K. Sympathetic modulation of hindlimb muscle contractility is altered in aged rats. Sci Rep 2023; 13:7504. [PMID: 37193678 DOI: 10.1038/s41598-023-33821-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/19/2023] [Indexed: 05/18/2023] Open
Abstract
It has recently been demonstrated that reflex excitation of muscle sympathetic nerves triggered by muscle contraction contributes to the maintenance of tetanic force (TF) in rat hindlimb muscles. We hypothesized that this feedback mechanism between the contraction of hindlimb muscles and the lumbar sympathetic nerves declines during aging. In this study, we examined the contribution of sympathetic nerves on skeletal muscle contractility in young adult (4-9 months old, n = 11) and aged (32-36 months old, n = 11) male and female rats. The tibial nerve was electrically stimulated to measure the TF of the triceps surae muscles resulting from motor nerve activation before and after cutting or stimulating (at 5-20 Hz) the lumbar sympathetic trunk (LST). The TF amplitude decreased by cutting the LST in the young and aged groups; however, the magnitude of the decrease in TF following transection of the LST in the aged rats (6.2%) was significantly (P = 0.02) smaller compared with that in the young rats (12.9%). The TF amplitude was increased by LST stimulation at ≥ 5 Hz in the young and ≥ 10 Hz in the aged groups. The overall TF response to LST stimulation was not significantly different between the two groups; however, an increase in muscle tonus resulting from LST stimulation, independent of motor nerve stimulation, was significantly (P = 0.03) greater in aged compared with young rats. The sympathetic contribution to support motor nerve-induced muscle contraction declined, whereas sympathetic-mediated muscle tonus, independent of motor nerve activity, was augmented in aged rats. These changes in sympathetic modulation of hindlimb muscle contractility may underlie the reduction of skeletal muscle strength during voluntary contraction and rigidity of motion during senescence.
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Affiliation(s)
- Harumi Hotta
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
| | - Kaori Iimura
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Nobuhiro Watanabe
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Harue Suzuki
- Department of Autonomic Neuroscience, Tokyo Metropolitan Institute for Geriatrics and Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan
| | - Masamitsu Sugie
- Health Promotion Management Office, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
| | - Kazuhiro Shigemoto
- Department of Geriatric Medicine, Tokyo Metropolitan Institute for Geriatrics and Gerontology, Tokyo, Japan
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20
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Bigalke JA, Durocher JJ, Greenlund IM, Keller-Ross M, Carter JR. Blood pressure and muscle sympathetic nerve activity are associated with trait anxiety in humans. Am J Physiol Heart Circ Physiol 2023; 324:H494-H503. [PMID: 36800506 PMCID: PMC10259854 DOI: 10.1152/ajpheart.00026.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023]
Abstract
Chronic anxiety is prevalent and associated with an increased risk of cardiovascular disease. Prior studies that have reported a relationship between muscle sympathetic nerve activity (MSNA) and anxiety have focused on participants with anxiety disorders and/or metabolic syndrome. The present study leverages a large cohort of healthy adults devoid of cardiometabolic disorders to examine the hypothesis that trait anxiety severity is positively associated with resting MSNA and blood pressure. Resting blood pressure (BP) (sphygmomanometer and finger plethysmography), MSNA (microneurography), and heart rate (HR; electrocardiogram) were collected in 88 healthy participants (52 males, 36 females, 25 ± 1 yr, 25 ± 1 kg/m2). Multiple linear regression was performed to assess the independent relationship between trait anxiety, MSNA, resting BP, and HR while controlling for age and sex. Trait anxiety was significantly correlated with systolic arterial pressure (SAP; r = 0.251, P = 0.018), diastolic arterial pressure (DAP; r = 0.291, P = 0.006), mean arterial pressure (MAP; r = 0.328, P = 0.002), MSNA burst frequency (BF; r = 0.237, P = 0.026), and MSNA burst incidence (BI; r = 0.225, P = 0.035). When controlling for the effects of age and sex, trait anxiety was independently associated with SAP (β = 0.206, P = 0.028), DAP (β = 0.317, P = 0.002), MAP (β = 0.325, P = 0.001), MSNA BF (β = 0.227, P = 0.030), and MSNA BI (β = 0.214, P = 0.038). Trait anxiety is associated with increased blood pressure and MSNA, demonstrating an important relationship between anxiety and autonomic blood pressure regulation.NEW & NOTEWORTHY Anxiety is associated with development of cardiovascular disease. Although the sympathetic nervous system is a likely mediator of this relationship, populations with chronic anxiety have shown little, if any, alteration in resting levels of directly recorded muscle sympathetic nerve activity (MSNA). The present study is the first to reveal an independent relationship between trait anxiety, resting blood pressure, and MSNA in a large cohort of healthy males and females devoid of cardiometabolic comorbidities.
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Affiliation(s)
- Jeremy A Bigalke
- Department of Health and Human Development, Montana State University, Bozeman, Montana, United States
- Department of Psychology, Montana State University, Bozeman, Montana, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
| | - John J Durocher
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
- Department of Biological Sciences and Integrative Physiology and Health Sciences Center, Purdue University Northwest, Hammond, Indiana, United States
| | - Ian M Greenlund
- Department of Psychology, Montana State University, Bozeman, Montana, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Manda Keller-Ross
- Division of Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, Minnesota, United States
| | - Jason R Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana, United States
- Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, Michigan, United States
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas, United States
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21
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Notarius CF, Floras JS. Influence of age on muscle sympathetic response to dynamic exercise. Exp Physiol 2023; 108:318-319. [PMID: 36634120 PMCID: PMC10103879 DOI: 10.1113/ep091009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 11/11/2022] [Indexed: 01/13/2023]
Affiliation(s)
- Catherine F. Notarius
- Clinical Cardiovascular Physiology Research LaboratoryUniversity Health Network and Sinai HealthTorontoOntarioCanada
- Faculty of Kinesiology and Physical EducationUniversity of TorontoTorontoOntarioCanada
| | - John S. Floras
- Clinical Cardiovascular Physiology Research LaboratoryUniversity Health Network and Sinai HealthTorontoOntarioCanada
- Department of MedicineUniversity of TorontoTorontoOntarioCanada
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22
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Faria D, Moll-Bernardes RJ, Testa L, Moniz CM, Rodrigues EC, Rodrigues AG, Araujo A, Alves MJ, Ono BE, Izaias JE, Salemi VM, Jordão CP, Amaro-Vicente G, Rondon MU, Ludwig KR, Craighead DH, Rossman MJ, Consolim-Colombo FM, De Angelis K, Irigoyen MC, Seals DR, Negrão CE, Sales AR. Sympathetic Neural Overdrive, Aortic Stiffening, Endothelial Dysfunction, and Impaired Exercise Capacity in Severe COVID-19 Survivors: A Mid-Term Study of Cardiovascular Sequelae. Hypertension 2023; 80:470-481. [PMID: 36416143 PMCID: PMC9847692 DOI: 10.1161/hypertensionaha.122.19958] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND COVID-19 has become a dramatic health problem during this century. In addition to high mortality rate, COVID-19 survivors are at increased risk for cardiovascular diseases 1-year after infection. Explanations for these manifestations are still unclear but can involve a constellation of biological alterations. We hypothesized that COVID-19 survivors compared with controls exhibit sympathetic overdrive, vascular dysfunction, cardiac morpho-functional changes, impaired exercise capacity, and increased oxidative stress. METHODS Nineteen severe COVID-19 survivors and 19 well-matched controls completed the study. Muscle sympathetic nerve activity (microneurography), brachial artery flow-mediated dilation and blood flow (Doppler-Ultrasound), carotid-femoral pulse wave velocity (Complior), cardiac morpho-functional parameters (echocardiography), peak oxygen uptake (cardiopulmonary exercise testing), and oxidative stress were measured ~3 months after hospital discharge. Complementary experiments were conducted on human umbilical vein endothelial cells cultured with plasma samples from subjects. RESULTS Muscle sympathetic nerve activity and carotid-femoral pulse wave velocity were greater and brachial artery flow-mediated dilation, brachial artery blood flow, E/e' ratio, and peak oxygen uptake were lower in COVID-19 survivors than in controls. COVID-19 survivors had lower circulating antioxidant markers compared with controls, but there were no differences in plasma-treated human umbilical vein endothelial cells nitric oxide production and reactive oxygen species bioactivity. Diminished peak oxygen uptake was associated with sympathetic overdrive, vascular dysfunction, and reduced diastolic function in COVID-19 survivors. CONCLUSIONS Our study revealed that COVID-19 survivors have sympathetic overactivation, vascular dysfunction, cardiac morpho-functional changes, and reduced exercise capacity. These findings indicate the need for further investigation to determine whether these manifestations are persistent longer-term and their impact on the cardiovascular health of COVID-19 survivors.
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Affiliation(s)
- Diego Faria
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.).,D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.)
| | - Renata J. Moll-Bernardes
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.)
| | - Laura Testa
- D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.)
| | - Camila M.V. Moniz
- D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.)
| | - Erika C. Rodrigues
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.)
| | - Amanda G. Rodrigues
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Amanda Araujo
- Department of Physiology, Federal University of São Paulo (UNIFESP), Brazil (A.A., K.D.A.)
| | - Maria J.N.N. Alves
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Bruna E. Ono
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.).,D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.)
| | - João E. Izaias
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.).,D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.)
| | - Vera M.C. Salemi
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Camila P. Jordão
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Graziela Amaro-Vicente
- School of Physical Education and Sport, University of São Paulo, Brazil (G.A.-V., M.U.P.B.R., C.E.N.)
| | - Maria U.P.B. Rondon
- School of Physical Education and Sport, University of São Paulo, Brazil (G.A.-V., M.U.P.B.R., C.E.N.)
| | - Katelyn R. Ludwig
- Department of Integrative Physiology, University of Colorado Boulder, CO (K.R.L., D.H.C., M.J.R., D.R.S.)
| | - Daniel H. Craighead
- Department of Integrative Physiology, University of Colorado Boulder, CO (K.R.L., D.H.C., M.J.R., D.R.S.)
| | - Matthew J. Rossman
- Department of Integrative Physiology, University of Colorado Boulder, CO (K.R.L., D.H.C., M.J.R., D.R.S.)
| | - Fernanda M. Consolim-Colombo
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Katia De Angelis
- Department of Physiology, Federal University of São Paulo (UNIFESP), Brazil (A.A., K.D.A.)
| | - Maria C.C. Irigoyen
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
| | - Douglas R. Seals
- Department of Integrative Physiology, University of Colorado Boulder, CO (K.R.L., D.H.C., M.J.R., D.R.S.)
| | - Carlos E. Negrão
- Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.).,School of Physical Education and Sport, University of São Paulo, Brazil (G.A.-V., M.U.P.B.R., C.E.N.)
| | - Allan R.K. Sales
- D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil (D.F., R.J.M.-B., E.C.R., B.E.O., J.E.I., A.R.K.S.).,D’Or Institute for Research and Education (IDOR), São Paulo, Brazil (D.F., L.T., C.M.V.M., B.E.O., J.E.I., A.R.K.S.).,Instituto do Coração, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, Brazil (A.G.R., M.J.N.N.A., V.M.C.S., C.P.J., F.M.C.-C., M.C.C.I., C.E.N., A.R.K.S.)
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23
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Badrov MB, Yoo JK, Hissen SL, Nelson DB, Shoemaker JK, Fu Q. Sympathetic Action Potential Firing and Recruitment Patterns Are Abnormal in Gestational Hypertension. Hypertension 2023; 80:291-301. [PMID: 36065805 PMCID: PMC9851937 DOI: 10.1161/hypertensionaha.122.19754] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/14/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND We tested the hypothesis that women who develop gestational hypertension (GH) display abnormal sympathetic action potential (AP) discharge patterns during late pregnancy (32-36 weeks), both at supine rest and during postural stress. METHODS Thirteen nonpregnant, female controls (nonpregnant controls [CTRL]) and 32 pregnant women participated; 14 had low-risk (no personal history of GH) normal pregnancies (LR-NP), 10 had high-risk (personal history of GH) normal pregnancies (HR-NP), and 8 developed GH. We measured heart rate, blood pressure, and muscle sympathetic nerve activity (microneurography) at supine rest and 60° head-up tilt. Sympathetic AP patterns were studied using wavelet-based methodology. RESULTS At rest, muscle sympathetic nerve activity burst frequency was elevated in LR-NP, HR-NP, and GH versus CTRL (all P≤0.01); however, the AP content per integrated burst was augmented only in GH (20±5 spikes/burst), compared with CTRL (8±3 spikes/burst), LR-NP (9±2 spikes/burst) and HR-NP (11±4 spikes/burst; all P<0.0001). Thus, total AP firing frequency was greater in GH versus each of CTRL, LR-NP, and HR-NP (all P<0.0001). In pregnancy, AP frequency is related directly to systolic (R2=46%) and diastolic (R2=20%) blood pressure (both P≤0.01). Unlike CTRL (both P<0.01), women who developed GH were unable to increase within-burst AP firing (P=0.71) or recruit latent subpopulations of larger-sized APs (P=0.72) in response to head-up tilt, perhaps related to a ceiling-effect; however, total AP firing frequency in the upright posture was elevated in the GH cohort versus CTRL, LR-NP, and HR-NP (all P<0.05). CONCLUSIONS Women who develop GH display aberrant sympathetic AP firing patterns in both the supine and upright postures.
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Affiliation(s)
- Mark B. Badrov
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Medicine, Toronto General Health Research Institute, University Health Network, Toronto, ON, Canada
| | - Jeung-Ki Yoo
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sarah L. Hissen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - David B. Nelson
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - J. Kevin Shoemaker
- School of Kinesiology, Western University, London, ON, Canada
- Department of Physiology and Pharmacology, Western University, London, ON, Canada
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, TX, USA
- University of Texas Southwestern Medical Center, Dallas, TX, USA
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24
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D'Souza AW, Hissen SL, Okada Y, Jarvis SS, Washio T, Akins JD, Nelson DB, Fu Q. Differential regulation of sympathetic neural burst frequency and amplitude throughout normal pregnancy: a longitudinal study. Am J Physiol Regul Integr Comp Physiol 2023; 324:R249-R259. [PMID: 36534586 PMCID: PMC9902229 DOI: 10.1152/ajpregu.00239.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/29/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
Sympathetic activation is a hallmark of pregnancy. However, longitudinal assessments of muscle sympathetic nerve activity (MSNA) in pregnancy are scarce and have primarily focused on burst occurrence (frequency) at rest, despite burst strength (amplitude) representing distinct characteristics of sympathetic outflow. Thus, we assessed MSNA burst amplitude distributions in healthy women to determine the impact of normal pregnancy on neural discharge patterns in response to orthostatic stress. Twenty-six women were studied longitudinally during pre-, early- (4-8 wk of gestation), and late (32-36 wk) pregnancy, as well as postpartum (6-10 wk after delivery). MSNA, blood pressure (BP), and heart rate (HR) were measured in the supine posture and during graded head-up tilt (30° and 60° HUT). Mean and median MSNA burst amplitudes were used to characterize burst amplitude distribution. In late pregnancy, women demonstrated smaller increases in HR (P < 0.001) during 60° HUT and larger increases in systolic BP (P = 0.043) throughout orthostasis, compared with prepregnancy. The increase in MSNA burst frequency during late- relative to prepregnancy (Late: Δ14[10] vs. Pre: Δ21[9] bursts/min; P = 0.001) was smaller during 60° HUT, whereas increases in burst incidence were smaller in late- relative to prepregnancy throughout orthostasis (P = 0.009). Nonetheless, median burst amplitude was smaller throughout orthostasis in late compared with prepregnancy (P = 0.038). Thus, while supine MSNA burst frequency was greater in late pregnancy, increases in burst frequency and strength during orthostasis were attenuated. These smaller, orthostatically induced MSNA increases may reflect natural adaptions of pregnancy serving to prevent sympathetic hyper-reactivity that is common in pathological states.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular Research Laboratory, School of Kinesiology, Western University, London, Ontario, Canada
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Sarah L Hissen
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Yoshiyuki Okada
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Special Care Dentistry, Hiroshima University, Hiroshima, Japan
| | - Sara S Jarvis
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Takuro Washio
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - John D Akins
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - David B Nelson
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
| | - Qi Fu
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas
- Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas
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25
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Badrov MB, Keir DA, Tomlinson G, Notarius CF, Millar PJ, Kimmerly DS, Shoemaker JK, Keys E, Floras JS. Normal and excessive muscle sympathetic nerve activity in heart failure: implications for future trials of therapeutic autonomic modulation. Eur J Heart Fail 2023; 25:201-210. [PMID: 36459000 DOI: 10.1002/ejhf.2749] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 11/11/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
AIMS Patients with sympathetic excess are those most likely to benefit from novel interventions targeting the autonomic nervous system. To inform such personalized therapy, we identified determinants of augmented muscle sympathetic nerve activity (MSNA) in heart failure, versus healthy controls. METHODS AND RESULTS We compared data acquired in 177 conventionally-treated, stable non-diabetic patients in sinus rhythm, aged 18-79 years (149 males; 28 females; left ventricular ejection fraction [LVEF] 25 ± 11% [mean ± standard deviation]; range 5-60%), and, concurrently, under similar conditions, in 658 healthy, normotensive volunteers (398 males; aged 18-81 years). In heart failure, MSNA ranged between 7 and 90 bursts·min-1 , proportionate to heart rate (p < 0.0001) and body mass index (BMI) (p = 0.03), but was unrelated to age, blood pressure, or drug therapy. Mean MSNA, adjusted for age, sex, BMI, and heart rate, was greater in heart failure (+14.2 bursts·min-1 ; 95% confidence interval [CI] 12.1-16.3; p < 0.0001), but lower in women (-5.0 bursts·min-1 ; 95% CI 3.4-6.6; p < 0.0001). With spline modeling, LVEF accounted for 9.8% of MSNA variance; MSNA related inversely to LVEF below an inflection point of ∼21% (p < 0.006), but not above. Burst incidence was greater in ischaemic than dilated cardiomyopathy (p = 0.01), and patients with sleep apnoea (p = 0.03). Burst frequency correlated inversely with stroke volume (p < 0.001), cardiac output (p < 0.001), and peak oxygen consumption (p = 0.002), and directly with norepinephrine (p < 0.0001) and peripheral resistance (p < 0.001). CONCLUSION Burst frequency and incidence exceeded normative values in only ∼53% and ∼33% of patients. Such diversity encourages selective deployment of sympatho-modulatory therapies. Clinical characteristics can highlight individuals who may benefit from future personalized interventions targeting pathological sympathetic activation.
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Affiliation(s)
- Mark B Badrov
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Daniel A Keir
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
- School of Kinesiology, Western University, London, Ontario, Canada
| | - George Tomlinson
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Catherine F Notarius
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Philip J Millar
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Derek S Kimmerly
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
- Division of Kinesiology, School of Health and Performance, Dalhousie University, Halifax, Nova Scotia, Canada
| | - J Kevin Shoemaker
- School of Kinesiology, Western University, London, Ontario, Canada
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - Evan Keys
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - John S Floras
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
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26
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Heusser K, Tank J, Diedrich A, Fischer A, Heise T, Jordan J. Limited evidence for sympathetic neural overactivation in older patients with type 2 diabetes mellitus. Front Neurosci 2023; 16:1107752. [PMID: 36711125 PMCID: PMC9878600 DOI: 10.3389/fnins.2022.1107752] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 12/30/2022] [Indexed: 01/13/2023] Open
Abstract
Introduction Mechanistic studies suggested that excess sympathetic activity promotes arterial hypertension while worsening insulin sensitivity. Older patients with type 2 diabetes are at particularly high cardiovascular and metabolic risk. However, data on sympathetic activity in this population is scarce. Methods We studied 61 patients with type 2 diabetes mellitus (22 women, 60.9 ± 1.4 years; 39 men, 60.9 ± 1.4 years). They had to have diabetes for at least 2 years, a hemoglobin A1c of 6.5-10%, a body-mass-index of 20-40 kg/m2, and had to be treated with stable doses of metformin only. We recorded ECG, finger and brachial blood pressure, and muscle sympathetic nerve activity (MSNA). Results MSNA was 37.5 ± 2.5 bursts/min in women and 39.0 ± 2.0 bursts/min in men (p = 0.55). MSNA expressed as burst incidence was 52.7 ± 2.0 bursts/100 beats in women and 59.2 ± 3.1 bursts/100 beats in men (p = 0.21). Five out of 39 men (12.8%) and two out of 22 women (9.1%) exhibited resting MSNA measurements above the 95th percentile for sex and age. In the pooled analysis, MSNA was not significantly correlated with systolic blood pressure, diastolic blood pressure, body mass index, waist circumference, body composition, or HbA1c (r 2 < 0.02, p > 0.26 for all). Discussion We conclude that relatively few older patients with type 2 diabetes mellitus exhibit increased MSNA. The large interindividual variability in MSNA cannot be explained by gender, blood pressure, body mass index, or glycemic control.
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Affiliation(s)
- Karsten Heusser
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Jens Tank
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - André Diedrich
- Vanderbilt Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States,Department of Biomedical Engineering, School of Engineering, Vanderbilt University, Nashville, TN, United States
| | - Annelie Fischer
- Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany
| | - Tim Heise
- Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany
| | - Jens Jordan
- Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany,Medical Faculty, University of Cologne, Cologne, Germany,*Correspondence: Jens Jordan,
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27
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Jiang Y, Yabluchanskiy A, Deng J, Amil FA, Po SS, Dasari TW. The role of age-associated autonomic dysfunction in inflammation and endothelial dysfunction. GeroScience 2022; 44:2655-2670. [PMID: 35773441 PMCID: PMC9768093 DOI: 10.1007/s11357-022-00616-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/22/2022] [Indexed: 01/23/2023] Open
Abstract
Aging of the cardiovascular regulatory function manifests as an imbalance between the sympathetic and parasympathetic (vagal) components of the autonomic nervous system (ANS). The most characteristic change is sympathetic overdrive, which is manifested by an increase in the muscle sympathetic nerve activity (MSNA) burst frequency with age. Age-related changes that occur in vagal nerve activity is less clear. The resting tonic parasympathetic activity can be estimated noninvasively by measuring the increase in heart rate occurring in response to muscarinic cholinergic receptor blockade; animal study models have shown this to diminish with age. Humoral, cellular, and neural mechanisms work together to prevent non-resolving inflammation. This review focuses on the mechanisms underlying age-related alternations in the ANS and how an imbalance in the ANS, evaluated by MSNA and heart rate variability (HRV), potentially facilitates inflammation when the homeostatic mechanisms between reflex neural circuits and the immune system are compromised, particularly the dysfunction of the cholinergic anti-inflammatory reflex. Physiologically, the efferent arm of this reflex acts via the [Formula: see text] 7 nicotinic acetylcholine receptors expressed in macrophages, monocytes, dendritic cells, T cells, and endothelial cells to curb the release of inflammatory cytokines, in which inhibition of NF‑κB nuclear translocation and activation of a JAK/STAT-mediated signaling cascade in macrophages and other immune cells are implicated. This reflex is likely to become less adequate with advanced age. Consequently, a pro-inflammatory state induced by reduced vagus output with age is associated with endothelial dysfunction and may significantly contribute to the development and propagation of atherosclerosis, heart failure, and hypertension. The aim of this review is to summarize the relationship between ANS dysfunction, inflammation, and endothelial dysfunction in the context of aging. Meanwhile, this review also attempts to describe the role of HRV measures as a predictor of the level of inflammation and endothelial dysfunction in the aged population and explore the possible therapeutical effects of vagus nerve stimulation.
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Affiliation(s)
- Yunqiu Jiang
- Cardiovascular Section, Department of Internal Medicine, University of Oklahoma Health Sciences Center, 800 SL Young Blvd, COM 5400, Oklahoma City, OK, 73104, USA
| | - Andriy Yabluchanskiy
- Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jielin Deng
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, China
- Cardiovascular Research Institute, Wuhan University, Wuhan, 430060, China
- Hubei Key Laboratory of Cardiology, Wuhan, 430060, China
| | - Faris A Amil
- Cardiovascular Section, Department of Internal Medicine, University of Oklahoma Health Sciences Center, 800 SL Young Blvd, COM 5400, Oklahoma City, OK, 73104, USA
| | - Sunny S Po
- Cardiovascular Section, Department of Internal Medicine, University of Oklahoma Health Sciences Center, 800 SL Young Blvd, COM 5400, Oklahoma City, OK, 73104, USA
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tarun W Dasari
- Cardiovascular Section, Department of Internal Medicine, University of Oklahoma Health Sciences Center, 800 SL Young Blvd, COM 5400, Oklahoma City, OK, 73104, USA.
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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28
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Lee E, Anselmo M, Tahsin CT, Vanden Noven M, Stokes W, Carter JR, Keller-Ross ML. Vasomotor symptoms of menopause, autonomic dysfunction, and cardiovascular disease. Am J Physiol Heart Circ Physiol 2022; 323:H1270-H1280. [PMID: 36367692 PMCID: PMC9744645 DOI: 10.1152/ajpheart.00477.2022] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/18/2022] [Accepted: 11/04/2022] [Indexed: 11/13/2022]
Abstract
Cardiovascular disease (CVD), the leading cause of death among US adults, is more prevalent in menopausal females compared with age-matched males. Vasomotor symptoms of menopause (VMS; hot flashes/flushes and night sweats) are common among females undergoing menopausal transition and have been associated with elevated blood pressure (BP) and increased CVD risk. Autonomic dysregulation of BP has been posited as a contributing factor to the elevated CVD risk in menopausal females with VMS. This review includes 1) a brief overview of the relationship between VMS and CVD, 2) mechanisms of hot flushes and their potential impact on short- and long-term BP regulation, and 3) how the disruption of autonomic function associated with VMS might provide a mechanistic pathway to CVD development. Finally, this review will highlight knowledge gaps and future directions toward better understanding of hot flush physiology and VMS contributions to CVD.
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Affiliation(s)
- Emma Lee
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Miguel Anselmo
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Chowdhury Tasnova Tahsin
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
| | | | - William Stokes
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
| | - Jason R Carter
- Department of Health and Human Development, Montana State University, Bozeman, Montana
- Robbins College of Health and Human Sciences, Baylor University, Waco, Texas
| | - Manda L Keller-Ross
- Division of Physical Therapy, Medical School, University of Minnesota, Minneapolis, Minnesota
- Division of Rehabilitation Science, Medical School, University of Minnesota, Minneapolis, Minnesota
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29
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Rim D, Henderson LA, Macefield VG. Brain and cardiovascular-related changes are associated with aging, hypertension, and atrial fibrillation. Clin Auton Res 2022; 32:409-422. [PMID: 36409380 DOI: 10.1007/s10286-022-00907-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022]
Abstract
PURPOSE The neural pathways in which the brain regulates the cardiovascular system is via sympathetic and parasympathetic control of the heart and sympathetic control of the systemic vasculature. Various cortical and sub-cortical sites are involved, but how these critical brain regions for cardiovascular control are altered in healthy aging and other risk conditions that may contribute to cardiovascular disease is uncertain. METHODS Here we review the functional and structural brain changes in healthy aging, hypertension, and atrial fibrillation - noting their potential influence on the autonomic nervous system and hence on cardiovascular control. RESULTS Evidence suggests that aging, hypertension, and atrial fibrillation are each associated with functional and structural changes in specific areas of the central nervous system involved in autonomic control. Increased muscle sympathetic nerve activity (MSNA) and significant alterations in the brain regions involved in the default mode network are commonly reported in aging, hypertension, and atrial fibrillation. CONCLUSIONS Further studies using functional and structural magnetic resonance imaging (MRI) coupled with autonomic nerve activity in healthy aging, hypertension, and atrial fibrillation promise to reveal the underlying brain circuitry modulating the abnormal sympathetic nerve activity in these conditions. This understanding will guide future therapies to rectify dysregulation of autonomic and cardiovascular control by the brain.
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Affiliation(s)
- Donggyu Rim
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia.,Baker Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia
| | - Luke A Henderson
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Camperdown, NSW, 2050, Australia
| | - Vaughan G Macefield
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, 3004, Australia. .,Baker Heart and Diabetes Institute, 75 Commercial Rd, Melbourne, VIC, 3004, Australia. .,Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC, 3010, Australia.
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30
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Badrov MB, Keir DA, Notarius CF, O'Donnell E, Millar PJ, Kimmerly DS, Shoemaker JK, Floras JS. Influence of sex and age on the relationship between aerobic fitness and muscle sympathetic nerve activity in healthy adults. Am J Physiol Heart Circ Physiol 2022; 323:H934-H940. [PMID: 36206052 DOI: 10.1152/ajpheart.00450.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We examined the influence of sex and age on the relationship between aerobic fitness and muscle sympathetic nerve activity (MSNA) in healthy adults. Data were assessed from 224 volunteers (88 females), aged 18-76 yr, in whom resting MSNA (microneurography) and peak oxygen uptake (V̇o2peak; incremental exercise test) were evaluated. When separated into younger (<50 yr) and older (≥50 yr) subgroups, there were inverse relationships between relative V̇o2peak (mL·kg-1·min-1) and MSNA burst frequency in younger males (R2 = 0.21, P < 0.0001) and older females (R2 = 0.36, P < 0.01), but not older males (R2 = 0.05, P = 0.08) or younger females (R2 = 0.03, P = 0.14). Similar patterns were observed with absolute V̇o2peak (L·min-1) and percent-predicted (based on age, sex, weight, height, and modality), and with burst incidence. Sex and age influence the relationship between aerobic fitness and resting MSNA, and, thus, must be considered as key variables when studying these potential associations; inverse relationships are strongest in younger males and older females.NEW & NOTEWORTHY Our data reveal for the first time that associations between aerobic fitness and resting muscle sympathetic nerve activity are sex and age specific; inverse relationships are evident in younger males (<50 yr) and older females (≥50 yr), but absent in younger females (<50 yr) and older males (≥50 yr).
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Affiliation(s)
- Mark B Badrov
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Daniel A Keir
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,School of Kinesiology, Western University, London, Ontario, Canada
| | - Catherine F Notarius
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
| | - Emma O'Donnell
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,School of Sport and Exercise Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Philip J Millar
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Derek S Kimmerly
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada.,Division of Kinesiology, School of Health and Performance, Dalhousie University, Halifax, Nova Scotia, Canada
| | - J Kevin Shoemaker
- School of Kinesiology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - John S Floras
- University Health Network and Sinai Health Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Hospital Research Institute, Toronto, Ontario, Canada
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31
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Anderson GK, Rickards CA. The potential therapeutic benefits of low frequency haemodynamic oscillations. J Physiol 2022; 600:3905-3919. [PMID: 35883272 PMCID: PMC9444954 DOI: 10.1113/jp282605] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 07/22/2022] [Indexed: 11/08/2022] Open
Abstract
Haemodynamic oscillations occurring at frequencies below the rate of respiration have been observed experimentally for more than a century. Much of the research regarding these oscillations, observed in arterial pressure and blood flow, has focused on mechanisms of generation and methods of quantification. However, examination of the physiological role of these oscillations has been limited. Multiple studies have demonstrated that oscillations in arterial pressure and blood flow are associated with the protection in tissue oxygenation or functional capillary density during conditions of reduced tissue perfusion. There is also evidence that oscillatory blood flow can improve clearance of interstitial fluid, with a growing number of studies demonstrating a role for oscillatory blood flow to aid in clearance of debris from the brain. The therapeutic potential of these haemodynamic oscillations is an important new area of research which may have beneficial impact in treating conditions such as stroke, cardiac arrest, blood loss injuries, sepsis, or even Alzheimer's disease and vascular dementia.
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Affiliation(s)
- Garen K Anderson
- Cerebral & Cardiovascular Physiology Laboratory, Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Caroline A Rickards
- Cerebral & Cardiovascular Physiology Laboratory, Department of Physiology & Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
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32
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Stute NL, Szeghy RE, Stickford JL, Province VP, Augenreich MA, Ratchford SM, Stickford ASL. Longitudinal observations of sympathetic neural activity and hemodynamics during 6 months recovery from SARS-CoV-2 infection. Physiol Rep 2022; 10:e15423. [PMID: 36151607 PMCID: PMC9508384 DOI: 10.14814/phy2.15423] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 07/14/2022] [Accepted: 07/23/2022] [Indexed: 06/16/2023] Open
Abstract
Cross-sectional data indicate that acute SARS-CoV-2 infection increases resting muscle sympathetic nerve activity (MSNA) and alters hemodynamic responses to orthostasis in young adults. However, the longitudinal impact of contracting SARS-CoV-2 on autonomic function remains unclear. The aim of this study was to longitudinally track MSNA, sympathetic transduction to blood pressure (BP), and hemodynamics over 6 months following SARS-CoV-2 infection. Young adults positive with SARS-CoV-2 reported to the laboratory three times over 6 months (V1:41 ± 17, V2:108 ± 21, V3:173 ± 16 days post-infection). MSNA, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were measured at rest, during a cold pressor test (CPT), and at 30° head-up tilt (HUT). Basal SBP (p = 0.019) and DBP (p < 0.001) decreased throughout the 6 months, whereas basal MSNA and HR were not different. Basal sympathetic transduction to BP and estimates of baroreflex sensitivity did not change over time. SBP and DBP were lower during CPT (SBP: p = 0.016, DBP: p = 0.007) and HUT at V3 compared with V1 (SBP: p = 0.041, DBP: p = 0.017), with largely no changes in MSNA. There was a trend toward a visit-by-time interaction for burst incidence (p = 0.055) during HUT, wherein at baseline immediately prior to tilting, burst incidence was lower at V3 compared with V1 (p = 0.014), but there were no differences between visits in the 30 HUT position. These results support impairments to cardiovascular health, and potentially autonomic function, which may improve over time. However, the improvements in BP over 6 months recovery from mild SARS-CoV-2 infection are likely not a direct result of changes in sympathetic activity.
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Affiliation(s)
- Nina L. Stute
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
| | - Rachel E. Szeghy
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
| | - Jonathon L. Stickford
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
| | - Valesha P. Province
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
| | - Marc A. Augenreich
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
| | - Stephen M. Ratchford
- Department of Health and Exercise ScienceAppalachian State UniversityBooneNorth CarolinaUSA
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33
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D'Souza AW, Klassen SA, Badrov MB, Lalande S, Shoemaker JK. Aging is associated with enhanced central, but impaired peripheral arms of the sympathetic baroreflex arc. J Appl Physiol (1985) 2022; 133:349-360. [PMID: 35736951 DOI: 10.1152/japplphysiol.00045.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that the baroreflex control of action potential (AP) subpopulations would be blunted in older compared to young adults. Integrated muscle sympathetic nerve activity (MSNA) and the underlying sympathetic APs were obtained using microneurography and a continuous wavelet analysis approach, respectively, during 5 minutes of supine rest in 13 older (45-75 years, 6 females) and 14 young (21-30 years, 7 females) adults. Baroreflex threshold relationships were quantified as the slope of the linear regression between MSNA burst probability (%) and diastolic blood pressure (mmHg), or AP cluster firing probability (%) and diastolic blood pressure (mmHg). Integrated MSNA baroreflex threshold gain was greater in older compared to young adults (older: -7.6±3.6 %/mmHg vs. Young: -3.5±1.5 %/mmHg, P<0.001). Similarly, the baroreflex threshold gain of AP clusters was modified by aging (group-by-cluster effect: P<0.001) such that older adults demonstrated greater baroreflex threshold gains of medium-sized AP clusters (e.g., Cluster 4, older: -8.2±3.2 %/mmHg vs. Young: -3.6±1.9 %/mmHg, P=0.003) but not for the smallest- (Cluster 1, older: -1.6±1.9 %/mmHg vs. Young: -1.0±1.7 %/mmHg, P>0.999) and largest-sized (Cluster 10, older: -0.5±0.5 %/mmHg vs. Young: -0.2±0.1 %/mmHg, P=0.819) AP clusters compared to young adults. In contrast, the peak change in mean arterial pressure (MAP) following a spontaneous MSNA burst (i.e., sympathetic transduction) was impaired with aging (older: -0.7±0.3 mmHg vs. Young: 1.8±1.2 mmHg, P<0.001). We conclude that aging is associated with elevated baroreflex control over high-probability AP content of sympathetic bursts that may compensate for impaired sympathetic neurovascular transduction.
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Affiliation(s)
- Andrew W D'Souza
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada
| | - Stephen A Klassen
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mark B Badrov
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,University Health Network and Sinai Health System Division of Cardiology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Sophie Lalande
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, United States
| | - J Kevin Shoemaker
- Neurovascular research laboratory, School of Kinesiology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
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34
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O’Brien MW, Mekary S, Kimmerly DS. Aging, cardiorespiratory fitness and sympathetic transduction. Aging (Albany NY) 2022; 14:4189-4190. [PMID: 35580001 PMCID: PMC9186775 DOI: 10.18632/aging.204091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/14/2022] [Indexed: 11/25/2022]
Affiliation(s)
- Myles W. O’Brien
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Said Mekary
- Department of Family Medicine, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Derek S. Kimmerly
- Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, Halifax, Nova Scotia, Canada
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35
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Sugimoto H, Hamaoka T, Murai H, Hirai T, Mukai Y, Kusayama T, Takashima S, Kato T, Takata S, Usui S, Sakata K, Kawashiri M, Takamura M. Relationships between muscle sympathetic nerve activity and novel indices of arterial stiffness using single oscillometric cuff in patients with hypertension. Physiol Rep 2022; 10:e15270. [PMID: 35587702 PMCID: PMC9118049 DOI: 10.14814/phy2.15270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 03/31/2022] [Indexed: 06/15/2023] Open
Abstract
The arterial velocity pulse index (AVI) and arterial pressure-volume index (API) have been proposed as new arterial stiffness indices that can be measured using an oscillometric cuff. Sympathetic nerve activity (SNA) contributes to arterial stiffness via increasing vascular smooth muscle tone. However, the associations between SNA and the AVI or API are not understood. The purpose of this study was to evaluate the relationships between muscle sympathetic nerve activity (MSNA) and the AVI or API in healthy individuals and patients with hypertension (HT). Forty healthy individuals (40.1 ± 15.2 years, 8 females) (healthy group) and 40 patients with HT (60.2 ± 13.6, 18 females) (HT group) were included in this study. The AVI, API, MSNA, beat-by-beat blood pressure, and heart rate were recorded simultaneously. The AVI and API were higher in the HT group than in the healthy group (AVI, 26.1 ± 7.6 vs. 16.5 ± 4.0, p < 0.001; API, 31.2 ± 8.6 vs. 25.5 ± 7.2, p = 0.002). MSNA in the HT group was also higher than in the healthy group (p < 0.001). MSNA was correlated with the AVI, but not with the API, in both the healthy group (R = 0.52, p = 0.001) and HT group (R = 0.57, p < 0.001). MSNA was independently correlated with the AVI in multivariate analysis (ß = 0.34, p = 0.001). In conclusion, AVI, obtained by a simple and less user-dependent method, was related to the MSNA in healthy individuals and patients with HT.
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Affiliation(s)
- Hiroyuki Sugimoto
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Takuto Hamaoka
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
- Penn State Heart and Vascular InstitutePennsylvania State University College of MedicineHersheyPennsylvaniaUSA
| | - Hisayoshi Murai
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
- Kanazawa Municipal HospitalKanazawaJapan
| | - Tadayuki Hirai
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Yusuke Mukai
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Takashi Kusayama
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Shinichiro Takashima
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Takeshi Kato
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | | | - Soichiro Usui
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Kenji Sakata
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Masa‐Aki Kawashiri
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
| | - Masayuki Takamura
- Department of Cardiovascular MedicineKanazawa University Graduate School of Medical SciencesKanazawaJapan
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36
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Kulas B, Klassen S, Moir ME, Shoemaker JK. Interactive effects of apneic and baroreflex stress on neural coding strategies in human muscle sympathetic nerve activity. J Neurophysiol 2022; 127:1086-1097. [PMID: 35294276 DOI: 10.1152/jn.00395.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The sympathetic nervous system exhibits patterns of action potential (AP) discharge in human muscle sympathetic nerve activity that suggest coding strategies express reflex specificity. This study explored the interactive effects of baroreceptor unloading using lower body negative pressure (LBNP) and volitional end-expiratory apnea (APN) on sympathetic postganglionic neuronal discharge patterns inferred from the firing patterns of differently sized sympathetic AP clusters. Seven individuals were studied using multi-unit microneurography (fibular) and a continuous wavelet approach to quantify AP discharge probability, recruitment, and latency during APN performed under ambient conditions, -10 and -40 mmHg LBNP. Compared to the ambient condition, LBNP increased AP discharge rate at -10 and -40 mmHg and recruited larger previously-silent sympathetic neurons at -40 mmHg. Compared to spontaneous breathing, APN increased AP discharge when performed during the ambient condition (∆351±132 AP/min), -10 mmHg (∆423±184 AP/min), and -40 mmHg (∆355±278 AP/min; main effect APN: P<0.01; LBNP-by-APN interaction: P=0.55). APN recruited larger previously-silent AP clusters during the ambient condition (∆4±3; P<0.02) and -10 mmHg (∆4±3; P<0.01), but not -40 mmHg (∆0±2; P=0.53; LBNP-by-APN: P<0.01). LBNP did not affect AP latency. However, APN reduced AP latency similarly during all conditions (ambient pressure: ∆-0.04±0.04s, -10 mmHg: ∆-0.03±0.03s, -40 mmHg: ∆-0.03±0.04s; main effect APN: P<0.01; LBNP-by-APN: P=0.48). These data indicate that apneic and baroreflex mechanisms appear to additively modify the axonal discharge rate of previously active sympathetic postganglionic neurons and interact to affect recruitment of previously-silent sympathetic neurons. Reductions in AP latency due to apneic stress were not impacted by baroreflex unloading.
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Affiliation(s)
- Bartek Kulas
- Neurovascular Research Laboratory, School of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - Stephen Klassen
- Neurovascular Research Laboratory, School of Kinesiology, University of Western Ontario, London, Ontario, Canada.,Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - M Erin Moir
- Neurovascular Research Laboratory, School of Kinesiology, University of Western Ontario, London, Ontario, Canada
| | - J Kevin Shoemaker
- Neurovascular Research Laboratory, School of Kinesiology, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
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37
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Coovadia Y, Adler TE, Martin-Arrowsmith PW, Usselman CW. Sex differences in sympathetic neuro-vascular and neuro-hemodynamic relationships during the cold pressor test. Am J Physiol Regul Integr Comp Physiol 2022; 322:R411-R420. [PMID: 35293259 DOI: 10.1152/ajpregu.00223.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Muscle sympathetic nerve activity (MSNA) affects vascular resistance differently in women and men. However, whether this sex difference persists during pronounced increases in MSNA remains unclear. Therefore, the purpose of this study was to examine sex differences in neurovascular transduction during cold pressor test (CPT)-mediated sympatho-excitation. Integrated peroneal MSNA (microneurography) was measured at rest and during a 3-minute CPT in young healthy women (n=11) and men (n=10). Mean arterial pressure (MAP) was measured beat-by-beat (Finometer) and superficial femoral artery blood flow was measured using duplex ultrasound. Femoral vascular resistance (FVR) was quantified as MAP/femoral blood flow (mmHg/mL/min). Baseline MSNA was similar between women and men (14±9 vs 15±9 bursts/100hb, respectively; P=0.83), whereas MAP was lower (86±7 vs 92±4 mmHg; P=0.047), and FVR was greater in women than men (0.54±0.16 vs 0.36±0.15 mmHg/mL/min; P=0.02). CPT-induced increases in MSNA were similar between the sexes (+19±11 vs +26±14 bursts/100hb; P=0.26) while increases in MAP (+7±3 vs +10±3mmHg; P=0.03) and FVR (+3.2±18.6 vs +26.8±12.8%; P<0.01) were smaller in women than men. Within men, CPT- induced increases in MSNA predicted increases in MAP (R2=0.51, P=0.02) and FVR (R2=0.49, P=0.02). However, MSNA did not predict MAP (R2=0.11, P=0.35) or FVR (R2=0.07, P=0.46) in women. Our findings demonstrate that men experience robust CPT-induced MAP responses that are driven by both neuro-vascular (MSNA-FVR) and neuro-hemodynamic (MSNA-MAP) coupling. These relationships were not observed in women, indicating that even during pronounced increases in sympathetic outflow, MSNA is not predictive of vascular nor blood pressure outcomes in young healthy women.
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Affiliation(s)
- Yasmine Coovadia
- Cardiovascular Health and Autonomic Regulation Laboratory, McGill University, Montreal, Quebec, Canada
| | - Tessa E Adler
- Cardiovascular Health and Autonomic Regulation Laboratory, McGill University, Montreal, Quebec, Canada
| | - Patrick W Martin-Arrowsmith
- Exercise Metabolism and 6 Nutrition Research Lab, Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada
| | - Charlotte W Usselman
- Cardiovascular Health and Autonomic Regulation Laboratory, McGill University, Montreal, Quebec, Canada.,McGill Research Centre for Physical Activity and Health, McGill University, Montreal, Quebec, Canada
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38
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Wenner MM, Greaney JL, Matthews EL, McGinty S, Kaur J, Vongpatanasin W, Fadel PJ. Influence of Age and Estradiol on Sympathetic Nerve Activity Responses to Exercise in Women. Med Sci Sports Exerc 2022; 54:408-416. [PMID: 34711708 PMCID: PMC8847319 DOI: 10.1249/mss.0000000000002823] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Postmenopausal women (PMW) display exaggerated increases in blood pressure (BP) during exercise, yet the mechanism(s) involved remain unclear. Moreover, research on the impact of menopausal changes in estradiol on cardiovascular control during exercise are limited. Herein, we tested the hypothesis that sympathetic responses during exercise are augmented in PMWcompared with young women (YW), and estradiol administration attenuates these responses. METHODS Muscle sympathetic nerve activity (MSNA) and mean arterial pressure (MAP) were measured in 13 PMW (58 ± 1 yr) and 17 YW (22 ± 1 yr) during 2 min of isometric handgrip. Separately, MSNA and BP responses were measured during isometric handgrip in six PMW (53 ± 1 yr) before and after 1 month of transdermal estradiol (100 μg·d-1). A period of postexercise ischemia (PEI) to isolate muscle metaboreflex activation followed all handgrip bouts. RESULTS Resting MAP was similar between PMW and YW, whereas MSNA was greater in PMW (23 ± 3 vs 8 ± 1 bursts per minute; P < 0.05). During handgrip, the increases in MSNA (PMW Δ16 ± 2 vs YW Δ6 ± 1 bursts per minute; P < 0.05) and MAP (PMW Δ18 ± 2 vs YW Δ12 ± 2 mm Hg; P < 0.05) were greater in PMW and remained augmented during PEI. Estradiol administration decreased resting MAP but not MSNA in PMW. Moreover, MSNA (PMW (-E2) Δ27 ± 8 bursts per minute versus PMW (+E2) Δ12 ± 5 bursts per minute; P < 0.05) and MAP (Δ31 ± 8 mm Hg vs Δ20 ± 6 mm Hg; P < 0.05) responses during handgrip were attenuated in PMW after estradiol administration. Likewise, MAP responses during PEI were lower after estradiol. CONCLUSIONS These data suggest that PMW exhibit an exaggerated MSNA and BP response to isometric exercise, due in part to heightened metaboreflex activation. Furthermore, estradiol administration attenuated BP and MSNA responses to exercise in PMW.
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Affiliation(s)
- Megan M. Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | - Jody L. Greaney
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX
| | - Evan L. Matthews
- Department of Exercise Science and Physical Education, Montclair State University, Montclair, NJ
| | - Shane McGinty
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | - Jasdeep Kaur
- Department of Kinesiology and Health Education, University of Texas at Austin, Austin, TX
| | | | - Paul J. Fadel
- Department of Kinesiology, The University of Texas at Arlington, Arlington, TX
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39
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Kaye DM, Nanayakkara S, Wang B, Shihata W, Marques FZ, Esler M, Lambert G, Mariani J. Characterization of Cardiac Sympathetic Nervous System and Inflammatory Activation in HFpEF Patients. JACC Basic Transl Sci 2022; 7:116-127. [PMID: 35257038 PMCID: PMC8897162 DOI: 10.1016/j.jacbts.2021.11.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/12/2021] [Accepted: 11/16/2021] [Indexed: 02/07/2023]
Abstract
Although there is evidence for activation of the sympathetic nervous system and inflammatory pathways in peripheral blood samples, their relationship to myocardial activity is unknown. Using arterial and coronary sinus blood sampling, we have shown the presence of cardiac and systemic sympathetic activation in HFpEF patients. However although systemic inflammatory activation was readily apparent, there was detectable myocardial release of inflammatory cytokines. Key hemodynamic and demographic factors that typically cluster together in HFpEF appeared to drive cardiac sympathetic activation. The data suggest that there may be a role for antiadrenergic therapies in selected HFpEF patients.
We have shown that systemic and cardiac sympathetic activation is present in heart failure with preserved ejection fraction (HFpEF) patients. Conversely, whereas systemic inflammatory activation was also detected in HFpEF, we did not detect local myocardial release of inflammatory cytokines. Activation of the sympathetic system correlated with both hemodynamic and demographic factors that characteristically cluster together in HFpEF. Together these data suggest that there may be a role for antiadrenergic therapies in certain HFpEF patients. The study does not implicate locally derived cytokines in the myocardial biology of HFpEF, although systemic sources may contribute to the global pathophysiology of HFpEF.
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Affiliation(s)
- David M Kaye
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, Australia.,Department of Medicine, Monash University, Melbourne, Australia
| | - Shane Nanayakkara
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, Australia
| | - Bing Wang
- Department of Cardiology, Alfred Hospital, Melbourne, Australia.,Department of Medicine, Monash University, Melbourne, Australia
| | - Waled Shihata
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Francine Z Marques
- Hypertension Research Laboratory, School of Biological Sciences, Monash University, Melbourne, Australia
| | - Murray Esler
- Human Neurotransmitter Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Gavin Lambert
- Iverson Health Innovation Research Institute and School of Health Science, Swinburne University of Technology, Melbourne, Australia
| | - Justin Mariani
- Heart Failure Research Group, Baker Heart and Diabetes Institute, Melbourne, Australia.,Department of Cardiology, Alfred Hospital, Melbourne, Australia.,Department of Medicine, Monash University, Melbourne, Australia
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40
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Petterson JL, O'Brien MW, Ramsay DJ, Johnston W, O'Neill CD, Dogra S, Mekari S, Floras JS, Kimmerly DS. Sympathetic neurohemodynamic transduction is attenuated in older males independent of aerobic fitness. Clin Auton Res 2022; 32:73-76. [PMID: 35024990 DOI: 10.1007/s10286-021-00845-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/14/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Jennifer L Petterson
- Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada
| | - Myles W O'Brien
- Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada
| | - Diane J Ramsay
- Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada
| | - William Johnston
- Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada
| | - Carley D O'Neill
- Exercise Physiology and Cardiovascular Health Lab, University of Ottawa Heart Institute, Ottawa, ON, Canada.,Department of Family Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Shilpa Dogra
- Health and Human Performance Laboratory, Faculty of Health Sciences, University of Ontario Institute of Technology, Oshawa, ON, Canada.,Department of Family Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Said Mekari
- Department of Family Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - John S Floras
- University Health Network and Mount Sinai Hospital Division of Cardiology, Department of Medicine, University of Toronto and the Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Derek S Kimmerly
- Autonomic Cardiovascular Control and Exercise Laboratory, Division of Kinesiology, School of Health and Human Performance, Faculty of Health, Dalhousie University, 6230 South Street, Halifax, NS, B3H 4R2, Canada.
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41
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Sympathetic activation by obstructive sleep apnea: a challenging 'off-label' meta-analysis. J Hypertens 2022; 40:30-32. [PMID: 34857703 DOI: 10.1097/hjh.0000000000003058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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42
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Biffi A, Quarti-Trevano F, Bonzani M, Seravalle G, Corrao G, Mancia G, Grassi G. Neuroadrenergic activation in obstructive sleep apnoea syndrome: a new selected meta-analysis - revisited. J Hypertens 2022; 40:15-23. [PMID: 34857700 PMCID: PMC10871617 DOI: 10.1097/hjh.0000000000003045] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 10/22/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND Neuroadrenegic overdrive occurs in obstructive sleep apnoea syndrome (OSAS). However, the small sample size of the microneurographic studies, heterogeneity of the patients examined, presence of comorbidities, represented major weaknesses not allowing to precisely define the main features of the phenomenon, particularly in nonobese patients. OBJECTIVE This meta-analysis detected 14 microneurographic studies based on muscle sympathetic nerve activity (MSNA) quantification in uncomplicated OSAS of different clinical severity. METHODS The evaluation was extended to the relationships of MSNA with heart rate, anthropometric and blood pressure values, metabolic variables, apnoea-hypopnea index and oxygen saturation. RESULTS MSNA is activated markedly and almost homogeneously between studies, showing a progressive increase from the healthy state to mild, moderate and severe OSAS (46.03, 48.32, 71.84, 69.27 bursts/100 heart beats). Of special interest are the findings that MSNA is significantly related to the apnoea-hypopnea index, a marker of OSAS severity (r = 0.55, P = 0.04) but not to BMI, as it occurs in OSAS associated with obesity, and heart rate is significantly and directly related to MSNA and apnoea-hypopnea index (r = 0.68 and r = 0.60, respectively P = 0.03 and P = 0.02), thus representing a surrogate marker of the sympathetic overdrive. CONCLUSION OSAS, even when uncomplicated by other cardiometabolic disease, displays a marked sympathetic activation, reflected by the MSNA and heart rate behaviour, becoming a target of therapeutic interventions aimed at exerting sympathomoderating effects, such as continuous positive airway pressure.
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Affiliation(s)
- Annalisa Biffi
- Department of Statistics and Quantitative Methods, University Milano-Bicocca
- National Centre for Healthcare Research and Pharmacoepidemiology
| | - Fosca Quarti-Trevano
- Clinica Medica, Department of Medicine and Surgery, University of Milano-Bicocca
| | - Matilde Bonzani
- National Centre for Healthcare Research and Pharmacoepidemiology
| | - Gino Seravalle
- Department of Statistics and Quantitative Methods, University Milano-Bicocca
| | - Giovanni Corrao
- National Centre for Healthcare Research and Pharmacoepidemiology
- Clinica Medica, Department of Medicine and Surgery, University of Milano-Bicocca
| | - Giuseppe Mancia
- Policlinico di Monza, Monza and University Milano-Bicocca, Milan, Italy
| | - Guido Grassi
- Department of Statistics and Quantitative Methods, University Milano-Bicocca
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43
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Bigalke JA, Carter JR. Sympathetic Neural Control in Humans with Anxiety-Related Disorders. Compr Physiol 2021; 12:3085-3117. [PMID: 34964121 DOI: 10.1002/cphy.c210027] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Numerous conceptual models are used to describe the dynamic responsiveness of physiological systems to environmental pressures, originating with Claude Bernard's milieu intérieur and extending to more recent models such as allostasis. The impact of stress and anxiety upon these regulatory processes has both basic science and clinical relevance, extending from the pioneering work of Hans Selye who advanced the concept that stress can significantly impact physiological health and function. Of particular interest within the current article, anxiety is independently associated with cardiovascular risk, yet mechanisms underlying these associations remain equivocal. This link between anxiety and cardiovascular risk is relevant given the high prevalence of anxiety in the general population, as well as its early age of onset. Chronically anxious populations, such as those with anxiety disorders (i.e., generalized anxiety disorder, panic disorder, specific phobias, etc.) offer a human model that interrogates the deleterious effects that chronic stress and allostatic load can have on the nervous system and cardiovascular function. Further, while many of these disorders do not appear to exhibit baseline alterations in sympathetic neural activity, reactivity to mental stress offers insights into applicable, real-world scenarios in which heightened sympathetic reactivity may predispose those individuals to elevated cardiovascular risk. This article also assesses behavioral and lifestyle modifications that have been shown to concurrently improve anxiety symptoms, as well as sympathetic control. Lastly, future directions of research will be discussed, with a focus on better integration of psychological factors within physiological studies examining anxiety and neural cardiovascular health. © 2022 American Physiological Society. Compr Physiol 12:1-33, 2022.
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Affiliation(s)
- Jeremy A Bigalke
- Department of Psychology, Montana State University, Bozeman, Montana, USA
| | - Jason R Carter
- Department of Psychology, Montana State University, Bozeman, Montana, USA.,Department of Health and Human Development, Montana State University, Bozeman, Montana, USA
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44
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Robinson AT, Wenner MM, Charkoudian N. Differential influences of dietary sodium on blood pressure regulation based on race and sex. Auton Neurosci 2021; 236:102873. [PMID: 34509133 PMCID: PMC8627459 DOI: 10.1016/j.autneu.2021.102873] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 07/19/2021] [Accepted: 08/23/2021] [Indexed: 11/30/2022]
Abstract
There are clear differences between men and women, and differences among races, in the incidence and prevalence of hypertension. Furthermore, there is extensive inter-individual variability among humans in the extent to which sodium ingestion alters blood pressure. Orthostatic intolerance and orthostatic hypotension are more common in women; these are often treated with a high salt diet, which has variable efficacy in increasing blood volume and blood pressure. Conversely, people with certain forms of hypertension are often counseled to decrease their sodium intake. Non-Hispanic Black men and women have higher rates of hypertension compared to non-Hispanic White men and women and other racial/ethnic groups. In aggregate, Black women appear to have better orthostatic tolerance than White women. In the present paper, we summarize and evaluate the current evidence for mechanisms of blood pressure regulation in men and women, as well as differences between Black and White groups, with a focus on cardiovascular responses to salt and differences among these groups. We also provide a brief review of factors that are not traditionally considered to be "biological" - such as socio-economic disparities resulting from historic and contemporary inequity across racial groups. These non-biological factors have direct and substantial influences on cardiovascular mechanisms, as well as implications for the influences of salt and sodium intake on blood pressure and cardiovascular health. We conclude that both biological and socio-economic factors provide critical modulating influences when considering the impacts of sodium on cardiovascular health as functions of race and sex.
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Affiliation(s)
- Austin T Robinson
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, AL 36849, United States of America.
| | - Megan M Wenner
- Women's Cardiovascular Research Laboratory, Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19713, United States of America
| | - Nisha Charkoudian
- Thermal & Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760, United States of America
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45
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Neuroadrenergic activation in obstructive sleep apnea syndrome: a systematic review and meta-analysis. J Hypertens 2021; 39:2281-2289. [PMID: 34620811 DOI: 10.1097/hjh.0000000000002934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Neuroadrenergic overdrive occurs in obstructive sleep apnea syndrome (OSAS). However, the small sample size of the microneurographic studies, heterogeneity of the patients examined, presence of comorbidities, represented major weaknesses not allowing to precisely define the main features of the phenomenon, particularly in nonobese patients. OBJECTIVE This meta-analysis evaluated 850 participants recruited in 26 microneurographic studies, based on muscle sympathetic nerve activity (MSNA) quantification in uncomplicated OSAS of different clinical severity. METHODS The evaluation was extended to the relationships of MSNA with heart rate (HR), anthropometric and blood pressure (BP) values, metabolic variables, apnea-hypopnea index (AHI) and oxygen saturation. RESULTS MSNA is activated markedly and almost homogeneously between studies, showing a progressive increase from the healthy state to mild, moderate and severe OSAS (41.6, 48.3, 65.5 and 70.7 bursts/100 heart beats, respectively, P < 0.01). Of special interest are the findings that first, MSNA is significantly related to the AHI, a marker of OSAS severity (r = 0.55, P < 0.02) and O2 saturation but not to body weight and BMI, as it occurs in OSAS associated with obesity; and second, HR is significantly and directly related to MSNA and AHI (r = 0.56 and 0.46, P < 0.03 for both), thus representing a surrogate marker of the sympathetic overdrive. CONCLUSION OSAS, even when uncomplicated by other cardiometabolic disease, displays a marked sympathetic activation, reflected by the MSNA and HR behavior, becoming a target of therapeutic interventions aimed at exerting sympathomoderating effects, such as continuous positive airway pressure.
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46
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Ranadive SM, Dillon GA, Mascone SE, Alexander LM. Vascular Health Triad in Humans With Hypertension-Not the Usual Suspects. Front Physiol 2021; 12:746278. [PMID: 34658930 PMCID: PMC8517241 DOI: 10.3389/fphys.2021.746278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
Hypertension (HTN) affects more than one-third of the US population and remains the top risk factor for the development of cardiovascular disease (CVD). Identifying the underlying mechanisms for developing HTN are of critical importance because the risk of developing CVD doubles with ∼20 mmHg increase in systolic blood pressure (BP). Endothelial dysfunction, especially in the resistance arteries, is the primary site for initiation of sub-clinical HTN. Furthermore, inflammation and reactive oxygen and nitrogen species (ROS/RNS) not only influence the endothelium independently, but also have a synergistic influence on each other. Together, the interplay between inflammation, ROS and vascular dysfunction is referred to as the vascular health triad, and affects BP regulation in humans. While the interplay of the vascular health triad is well established, new underlying mechanistic targets are under investigation, including: Inducible nitric oxide synthase, hydrogen peroxide, hydrogen sulfide, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and nuclear factor activated T cells. This review outlines the role of these unusual suspects in vascular health and function in humans. This review connects the dots using these unusual suspects underlying inflammation, ROS and vascular dysfunction especially in individuals at risk of or with diagnosed HTN based on novel studies performed in humans.
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Affiliation(s)
- Sushant M Ranadive
- Department of Kinesiology, University of Maryland, College Park, College Park, MD, United States
| | - Gabrielle A Dillon
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, United States.,Center for Healthy Aging, The Pennsylvania State University, University Park, PA, United States
| | - Sara E Mascone
- Department of Kinesiology, University of Maryland, College Park, College Park, MD, United States
| | - Lacy M Alexander
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, United States.,Center for Healthy Aging, The Pennsylvania State University, University Park, PA, United States
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Nardone M, Katerberg C, Incognito AV, Teixeira AL, Vianna LC, Millar PJ. Blood pressure oscillations impact signal-averaged sympathetic transduction of blood pressure: implications for the association with resting sympathetic outflow. Am J Physiol Heart Circ Physiol 2021; 321:H798-H806. [PMID: 34506224 DOI: 10.1152/ajpheart.00422.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Signal-averaged sympathetic transduction of blood pressure (BP) is inversely related to resting muscle sympathetic nerve activity (MSNA) burst frequency in healthy cohorts. Whether this represents a physiological compensatory adaptation or a methodological limitation, remains unclear. The current analysis aimed to determine the contribution of methodological limitations by evaluating the dependency of MSNA transduction at different levels of absolute BP. Thirty-six healthy participants (27 ± 7 yr, 9 females) underwent resting measures of beat-to-beat heart rate, BP, and muscle sympathetic nerve activity (MSNA). Tertiles of mean arterial pressure (MAP) were computed for each participant to identify cardiac cycles occurring below, around, and above the MAP operating pressure (OP). Changes in hemodynamic variables were computed across 15 cardiac cycles within each MAP tertile to quantify sympathetic transduction. MAP increased irrespective of sympathetic activity when initiated below the OP, but with MSNA bursts provoking larger rises (3.0 ± 0.9 vs. 2.1 ± 0.7 mmHg; P < 0.01). MAP decreased irrespective of sympathetic activity when initiated above the OP, but with MSNA bursts attenuating the drop (-1.3 ± 1.1 vs. -3.1 ± 1.2 mmHg; P < 0.01). In participants with low versus high resting MSNA (12 ± 4 vs. 32 ± 10 bursts/min), sympathetic transduction of MAP was not different when initiated by bursts below (3.2 ± 1.0 vs. 2.8 ± 0.9 mmHg; P = 0.26) and above the OP (-1.0 ± 1.3 vs. -1.6 ± 0.8 mmHg; P = 0.08); however, low resting MSNA was associated with a smaller proportion of MSNA bursts firing above the OP (15 ± 5 vs. 22 ± 5%; P < 0.01). The present analyses demonstrate that the signal-averaging technique for calculating sympathetic transduction of BP is influenced by the timing of an MSNA burst relative to cyclic oscillations in BP.NEW & NOTEWORTHY The current signal-averaging technique for calculating sympathetic transduction of blood pressure does not consider the arterial pressure at which each muscle sympathetic burst occurs. A burst firing when mean arterial pressure is above the operating pressure was associated with a decrease in blood pressure. Thus, individuals with higher muscle sympathetic nerve activity demonstrate a reduced sympathetic transduction owing to the weighted contribution of more sympathetic bursts at higher levels of arterial pressure.
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Affiliation(s)
- Massimo Nardone
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Carlin Katerberg
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Anthony V Incognito
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - André L Teixeira
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Lauro C Vianna
- NeuroV̇ASQ̇-Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasilia, Brasilia, Federal District, Brazil
| | - Philip J Millar
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.,Toronto General Research Institute, Toronto General Hospital, Toronto, Ontario, Canada
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48
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Teixeira AL, Fernandes IA, Millar PJ, Vianna LC. GABA A receptor activation modulates the muscle sympathetic nerve activity responses at the onset of static exercise in humans. J Appl Physiol (1985) 2021; 131:1138-1147. [PMID: 34410847 DOI: 10.1152/japplphysiol.00423.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exercise is a well-known sympathoexcitatory stimulus. However, muscle sympathetic nerve activity (MSNA) can decrease during the onset of muscle contraction. Yet, the underlying mechanisms and neurotransmitters involved in the sympathetic responses at the onset of exercise remain unknown. Herein, we tested the hypothesis that GABAA receptors may contribute to the MSNA responses at the onset of static handgrip in humans. Thirteen young, healthy individuals (4 females) performed 30 s of ischemic static handgrip at 30% of maximum volitional contraction before and following oral administration of either placebo or diazepam (10 mg), a benzodiazepine that enhances GABAA activity. MSNA (microneurography), beat-to-beat blood pressure (finger photopletysmography), heart rate (electrocardiogram), and stroke volume (ModelFlow) were continuously measured. Cardiac output (CO = stroke volume × heart rate) and total vascular conductance (TVC = CO/mean blood pressure) were subsequently calculated. At rest, MSNA was reduced while hemodynamic variables were unchanged after diazepam administration. Before diazepam, static handgrip elicited a significant decrease in MSNA burst frequency (Δ-7 ± 2 bursts/min, P < 0.01 vs. baseline) and MSNA burst incidence (Δ-16 ± 2 bursts/100 heart beats, P < 0.01 vs. baseline); however, these responses were attenuated following diazepam administration (Δ-1 ± 2 bursts/min and Δ-7 ± 2 bursts/100 heart beats, respectively; P < 0.01 vs. before diazepam). Diazepam did not affect the increases in heart rate, blood pressure, CO, and TVC at the exercise onset. Importantly, the placebo had no effect on any variable at rest or exercise onset. These findings suggest that GABAA receptor activation modulates the MSNA responses at the onset of static exercise in young, healthy humans.NEW & NOTEWORTHY In this study, we found that the reduction in muscle sympathetic nerve activity at the onset of static handgrip exercise was blunted following GABAA receptor activation with oral administration of diazepam in young, healthy individuals. The present findings provide novel insight into neural circuitry mechanisms controlling muscle sympathetic outflow during exercise in humans.
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Affiliation(s)
- André L Teixeira
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.,NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Brazil
| | - Igor A Fernandes
- NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Brazil
| | - Philip J Millar
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Lauro C Vianna
- NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, Brazil
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49
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Stute NL, Stickford JL, Province VM, Augenreich MA, Ratchford SM, Stickford ASL. COVID-19 is getting on our nerves: sympathetic neural activity and haemodynamics in young adults recovering from SARS-CoV-2. J Physiol 2021; 599:4269-4285. [PMID: 34174086 PMCID: PMC8447023 DOI: 10.1113/jp281888#support-information-section] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/16/2021] [Indexed: 11/10/2023] Open
Abstract
KEY POINTS The impact of SARS-CoV-2 infection on autonomic and cardiovascular function in otherwise healthy individuals is unknown. For the first time it is shown that young adults recovering from SARS-CoV-2 have elevated resting sympathetic activity, but similar heart rate and blood pressure, compared with control subjects. Survivors of SARS-CoV-2 also exhibit similar sympathetic nerve activity and haemodynamics, but decreased pain perception, during a cold pressor test compared with healthy controls. Further, these individuals display higher sympathetic nerve activity throughout an orthostatic challenge, as well as an exaggerated heart rate response to orthostasis. If similar autonomic dysregulation, like that found here in young individuals, is present in older adults following SARS-CoV-2 infection, there may be substantial adverse implications for cardiovascular health. ABSTRACT The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can elicit systemic adverse physiological effects. However, the impact of SARS-CoV-2 on autonomic and cardiovascular function in otherwise healthy individuals remains unclear. Young adults who tested positive for SARS-CoV-2 (COV+; n = 16, 8 F) visited the laboratory 35 ± 16 days following diagnosis. Muscle sympathetic nerve activity (MSNA), systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) were measured in participants at rest and during a 2 min cold pressor test (CPT) and 5 min each at 30° and 60° head-up tilt (HUT). Data were compared with age-matched healthy controls (CON; n = 14, 9 F). COV+ participants (18.2 ± 6.6 bursts min-1 ) had higher resting MSNA burst frequency compared with CON (12.7 ± 3.4 bursts min-1 ) (P = 0.020), as well as higher MSNA burst incidence and total activity. Resting HR, SBP and DBP were not different. During CPT, there were no differences in MSNA, HR, SBP or DBP between groups. COV+ participants reported less pain during the CPT compared with CON (5.7 ± 1.8 vs. 7.2 ± 1.9 a.u., P = 0.036). MSNA was higher in COV+ compared with CON during HUT. There was a group-by-position interaction in MSNA burst incidence, as well as HR, in response to HUT. These results indicate resting sympathetic activity, but not HR or BP, may be elevated following SARS-CoV-2 infection. Further, cardiovascular and perceptual responses to physiological stress may be altered, including both exaggerated (orthostasis) and suppressed (pain perception) responses, compared with healthy young adults.
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Affiliation(s)
- Nina L. Stute
- Department of Health & Exercise ScienceAppalachian State UniversityBooneNCUSA
| | | | - Valesha M. Province
- Department of Health & Exercise ScienceAppalachian State UniversityBooneNCUSA
| | - Marc A. Augenreich
- Department of Health & Exercise ScienceAppalachian State UniversityBooneNCUSA
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DeLorey DS. Sympathetic vasoconstriction in skeletal muscle: Modulatory effects of aging, exercise training, and sex. Appl Physiol Nutr Metab 2021; 46:1437-1447. [PMID: 34348066 DOI: 10.1139/apnm-2021-0399] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sympathetic nervous system (SNS) is a critically important regulator of the cardiovascular system. The SNS controls cardiac output and its distribution, as well as peripheral vascular resistance and blood pressure at rest and during exercise. Aging is associated with increased blood pressure and decreased skeletal muscle blood flow at rest and in response to exercise. The mechanisms responsible for the blunted skeletal muscle blood flow response to dynamic exercise with aging have not been fully elucidated; however, increased muscle sympathetic nerve activity (MSNA), elevated vascular resistance and a decline in endothelium-dependent vasodilation are commonly reported in older adults. In contrast to aging, exercise training has been shown to reduce blood pressure and enhance skeletal muscle vascular function. Exercise training has been shown to enhance nitric oxide-dependent vascular function and may improve the vasodilatory capacity of the skeletal muscle vasculature; however, surprisingly little is known about the effect of exercise training on the neural control of circulation. The control of blood pressure and skeletal muscle blood flow also differs between males and females. Blood pressure and MSNA appear to be lower in young females compared to males. However, females experience a larger increase in MSNA with aging compared to males. The mechanism(s) for the altered SNS control of vascular function in females remain to be determined. Novelty: • This review will summarize our current understanding of the effects of aging, exercise training and sex on sympathetic vasoconstriction at rest and during exercise. • Areas where additional research is needed are also identified.
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Affiliation(s)
- Darren S DeLorey
- University of Alberta, Faculty of Kinesiology, Sport, and Recreation, Edmonton, Alberta, Canada;
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