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Watso JC, Robinson AT, Singar SAB, Cuba JN, Koutnik AP. Advanced cardiovascular physiology in an individual with type 1 diabetes after 10-year ketogenic diet. Am J Physiol Cell Physiol 2024; 327:C446-C461. [PMID: 38912731 DOI: 10.1152/ajpcell.00694.2023] [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: 12/13/2023] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 06/25/2024]
Abstract
Adults with type 1 diabetes (T1D) have an elevated risk for cardiovascular disease (CVD) compared with the general population. HbA1c is the primary modifiable risk factor for CVD in T1D. Fewer than 1% of patients achieve euglycemia (<5.7% HbA1c). Ketogenic diets (KD; ≤50 g carbohydrate/day) may improve glycemia and downstream vascular dysfunction in T1D by reducing HbA1c and insulin load. However, there are concerns regarding the long-term CVD risk from a KD. Therefore, we compared data collected in a 60-day window in an adult with T1D on exogenous insulin who consumed a KD for 10 years versus normative values in those with T1D (T1D norms). The participant achieved euglycemia with an HbA1c of 5.5%, mean glucose of 98 [5] mg/dL (median [interquartile range]), 90 [11]% time-in-range 70-180 mg/dL (T1D norms: 1st percentile for all), and low insulin requirements of 0.38 ± 0.03 IU/kg/day (T1D norms: 8th percentile). Seated systolic blood pressure (SBP) was 113 mmHg (T1D norms: 18th percentile), while ambulatory awake SBP was 132 ± 15 mmHg (T1D target: <130 mmHg), blood triglycerides were 69 mg/dL (T1D norms: 34th percentile), low-density lipoprotein was 129 mg/dL (T1D norms: 60th percentile), heart rate was 56 beats/min (T1D norms: >1SD below the mean), carotid-femoral pulse wave velocity was 7.17 m/s (T1D norms: lowest quartile of risk), flow-mediated dilation was 12.8% (T1D norms: >1SD above mean), and cardiac vagal baroreflex gain was 23.5 ms/mmHg (T1D norms: >1SD above mean). Finally, there was no indication of left ventricular diastolic dysfunction from echocardiography. Overall, these data demonstrate below-average CVD risk relative to T1D norms despite concerns regarding the long-term impact of a KD on CVD risk.NEW & NOTEWORTHY Adults with type 1 diabetes (T1D) have a 10-fold higher risk for cardiovascular disease (CVD) compared with the general population. We assessed cardiovascular health metrics in an adult with T1D who presented with a euglycemic HbA1c after following a ketogenic diet for the past 10 years. Despite concerns about the ketogenic diet increasing CVD risk, the participant exhibited below-average CVD risk relative to others with T1D when considering all outcomes together.
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Affiliation(s)
- Joseph C Watso
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, and Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Austin T Robinson
- Neurovascular Physiology Laboratory, Indiana University, Bloomington, Indiana, United States
| | - Saiful Anuar Bin Singar
- Department of Health, Nutrition, and Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Jens N Cuba
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, and Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Andrew P Koutnik
- Sansum Diabetes Research Institute, Santa Barbara, California, United States
- Human Healthspan, Resilience, and Performance, Florida Institute for Human and Machine Cognition, Pensacola, Florida, United States
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Watso JC, Cuba JN, Boutwell SL, Moss JE, Bowerfind AK, Fernandez IM, Cassette JM, May AM, Kirk KF. Acute nasal breathing lowers diastolic blood pressure and increases parasympathetic contributions to heart rate variability in young adults. Am J Physiol Regul Integr Comp Physiol 2023; 325:R797-R808. [PMID: 37867476 PMCID: PMC11178300 DOI: 10.1152/ajpregu.00148.2023] [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: 06/17/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect cardiovascular health. It is unknown whether the route of breathing (nasal vs. oral) affects prognostic cardiovascular variables. Because nasal breathing can improve other physiological variables (e.g., airway dilation), we hypothesized that nasal compared with oral breathing would acutely lower blood pressure (BP) and improve heart rate variability (HRV) metrics. We tested 20 adults in this study [13 females/7 males; age: 18(1) years, median (IQR); body mass index: 23 ± 2 kg·m-2, means ± SD]. We compared variables between nasal- and oral-only breathing (random order, five min each) using paired, two-tailed t tests or Wilcoxon signed-rank paired tests with significance set to P < 0.05. We report the median (interquartile range) for diastolic BP and means ± SD for all other variables. We found that nasal breathing was associated with a lower mean BP (nasal: 84 ± 7 vs. oral: 86 ± 5 mmHg, P = 0.006, Cohen's d = 0.70) and diastolic BP [nasal: 68(8) vs. oral: 72(5) mmHg, P < 0.001, Rank-biserial correlation = 0.89] but not systolic BP (nasal: 116 ± 11 vs. oral: 117 ± 9 mmHg, P = 0.48, Cohen's d = 0.16) or heart rate (HR; nasal: 74 ± 10 vs. oral: 75 ± 8 beats·min-1, P = 0.90, Cohen's d = 0.03). We also found that nasal breathing was associated with a higher high-frequency (HF) contribution to HRV (nasal: 59 ± 19 vs. oral: 52 ± 21%, P = 0.04, Cohen's d = 0.50) and a lower low frequency-to-HF ratio at rest (nasal: 0.9 ± 0.8 vs. oral: 1.2 ± 0.9, P = 0.04, Cohen's d = 0.49). These data suggest that nasal compared with oral breathing acutely 1) lowers mean and diastolic BP, 2) does not affect systolic BP or heart rate, and 3) increases parasympathetic contributions to HRV.NEW & NOTEWORTHY There is growing interest in how breathing pace, pattern, and training (e.g., device-guided or -resisted breathing) affect prognostic cardiovascular variables. However, the potential effects of the breathing route on prognostic cardiovascular variables are unclear. These data suggest that nasal compared with oral breathing 1) lowers mean and diastolic blood pressure (BP), 2) does not affect systolic BP or heart rate (HR), and 3) increases parasympathetic contributions to heart rate variability (HRV). These data suggest that acute nasal breathing improves several prognostic cardiovascular variables.
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Affiliation(s)
- Joseph C Watso
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Jens N Cuba
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Savannah L Boutwell
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Justine E Moss
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Allison K Bowerfind
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Isabela M Fernandez
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Jessica M Cassette
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Allyson M May
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
| | - Katherine F Kirk
- Cardiovascular and Applied Physiology Laboratory, Department of Health, Nutrition, & Food Sciences, Florida State University, Tallahassee, Florida, United States
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Linder BA, Babcock MC, Pollin KU, Watso JC, Robinson AT. Short-term high-salt consumption does not influence resting or exercising heart rate variability but increases MCP-1 concentration in healthy young adults. Am J Physiol Regul Integr Comp Physiol 2023; 324:R666-R676. [PMID: 36939211 PMCID: PMC10110701 DOI: 10.1152/ajpregu.00240.2022] [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] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/21/2023]
Abstract
High salt consumption increases blood pressure (BP) and cardiovascular disease risk by altering autonomic function and increasing inflammation. However, it is unclear whether salt manipulation alters resting and exercising heart rate variability (HRV), a noninvasive measure of autonomic function, in healthy young adults. The purpose of this investigation was to determine whether short-term high-salt intake 1) alters HRV at rest, during exercise, or exercise recovery and 2) increases the circulating concentration of the inflammatory biomarker monocyte chemoattractant protein 1 (MCP-1). With the use of a randomized, placebo-controlled, crossover study, 20 participants (8 females; 24 ± 4 yr old, 110 ± 10/64 ± 8 mmHg) consumed salt (3,900 mg sodium) or placebo capsules for 10 days each separated by ≥2 wk. We assessed HRV during 10 min of baseline rest, 50 min of cycling (60% V̇o2peak), and recovery. We quantified HRV using the standard deviation of normal-to-normal RR intervals, the root mean square of successive differences (RMSSD), and additional time and frequency domain metrics of HRV. Plasma samples were collected to assess MCP-1 concentration. No main effect of high salt or condition × time interaction was observed for HRV metrics. However, acute exercise reduced HRV (e.g., RMSSD time: P < 0.001, condition: P = 0.877, interaction: P = 0.422). High salt elevated plasma MCP-1 (72.4 ± 12.5 vs. 78.14 ± 14.7 pg/mL; P = 0.010). Irrespective of condition, MCP-1 was moderately associated (P values < 0.05) with systolic (r = 0.32) and mean BP (r = 0.33). Short-term high-salt consumption does not affect HRV; however, it increases circulating MCP-1, which may influence BP in young adults.
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Affiliation(s)
- Braxton A Linder
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama, United States
| | - Matthew C Babcock
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Kamila U Pollin
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
- War Related Illness and Injury Study Center, Washington DC Veteran Affairs Medical Center, Washington, District of Columbia, United States
| | - Joseph C Watso
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, Florida, United States
| | - Austin T Robinson
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama, United States
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
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Dumančić D, Stupin A, Kožul M, Šerić V, Kibel A, Goswami N, Brix B, Debeljak Ž, Scitovski R, Drenjančević I. Increased cerebral vascular resistance underlies preserved cerebral blood flow in response to orthostasis in humans on a high-salt diet. Eur J Appl Physiol 2023; 123:923-933. [PMID: 36598577 DOI: 10.1007/s00421-022-05124-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023]
Abstract
Cerebral blood flow autoregulation protects brain tissue from blood pressure variations and maintains cerebral perfusion pressure by changes in vascular resistance. High salt (HS) diet impairs endothelium-dependent vasodilation in many vascular beds, including cerebral microcirculation, and may affect vascular resistance. The aim of present study was to determine if 7-day HS diet affected the reactivity of middle cerebral artery (MCA) to orthostatic challenge in healthy human individuals, and if autoregulatory mechanisms and sympathetic neural regulation were involved in this phenomenon.Twenty-seven persons participated in study (F:21, M:6, age range 19-24). Participants consumed 7-day low-salt (LS) diet (< 2.3 g kitchen salt/day) and afterwards 7-day HS diet (> 11.2 g kitchen salt/day). Blood and urine analysis and anthropometric measurements were performed after each diet. Arterial blood pressure, heart rate and heart rate variability, and cerebral and systemic hemodynamic parameters were recorded simultaneously with transcranial Doppler ultrasound and The Task Force® Monitor in response to orthostatic test.Participants remained normotensive during HS diet. Following both, the LS and HS dietary protocols, mean cerebral blood flow (CBF), as well as the velocity time integral and diastolic blood pressure decreased, and cerebral pulsatility index increased after rising up. Importantly, cerebrovascular resistance significantly increased in response to orthostasis only after HS diet. Urine concentration of noradrenaline and vanillylmandelic acid, baroreflex sensitivity (BRS), and sympathetic neural control was significantly decreased in HS diet.Results suggest that CBF in response to orthostatic test was preserved in HS condition due to altered vascular reactivity of MCA, with increased cerebrovascular resistance and blunted BRS and sympathetic activity.
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Affiliation(s)
- Dijana Dumančić
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Diagnostic and Interventional Radiology, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Ana Stupin
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Maja Kožul
- Department of Dermatology and Venereology, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Vatroslav Šerić
- Department of Clinical Laboratory Diagnostics, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Aleksandar Kibel
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Heart and Vascular Diseases, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Nandu Goswami
- Physiology Division, Otto Loewi Research Center, Medical University of Graz, Auenbruggerplatz 2, 8036, Graz, Austria
| | - Bianca Brix
- Physiology Division, Otto Loewi Research Center, Medical University of Graz, Auenbruggerplatz 2, 8036, Graz, Austria
| | - Željko Debeljak
- Department of Clinical Laboratory Diagnostics, University Hospital Centre Osijek, J. Huttlera 4, 31000, Osijek, Croatia
- Department of Pharmacology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia
| | - Rudolf Scitovski
- Department of Mathematics, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ines Drenjančević
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000, Osijek, Croatia.
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Babcock MC, DuBose LE, Hildreth KL, Stauffer BL, Cornwell WK, Kohrt WM, Moreau KL. Age-associated reductions in cardiovagal baroreflex sensitivity are exaggerated in middle-aged and older men with low testosterone. J Appl Physiol (1985) 2022; 133:403-415. [PMID: 35771224 PMCID: PMC9359637 DOI: 10.1152/japplphysiol.00245.2022] [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
Aging is associated with reductions in cardiovagal baroreflex sensitivity (cBRS), which increases cardiovascular disease risk. Preclinical data indicate that low testosterone reduces cBRS. We determined whether low testosterone is associated with reduced cBRS in healthy men. METHODS Twenty-six men categorized as young (N=6; age=31±4 years; testosterone=535±60 ng/dL), middle-aged/older with normal (N=10; aged 56±3 years; testosterone=493±85 ng/dL), or low (N=10; age=57±6 years; testosterone=262±31 ng/dL) testosterone underwent recordings of beat-by-beat blood pressure and R-R interval during rest and two Valsalva maneuvers, and measures of carotid artery compliance. IL-6, CRP, oxidized LDL cholesterol and TAS were measured. RESULTS Middle-aged/older men had lower cBRS compared to young men (17.0±6.5 ms/mmHg; p=0.028); middle-age/older men with low testosterone had lower cBRS (5.5±3.2 ms/mmHg; p=0.039) compared to age-matched men with normal testosterone (10.7±4.0 ms/mmHg). No differences existed among groups during Phase II of the Valsalva maneuver; middle-aged/older men with low testosterone had reduced cBRS (4.7±2.6 ms/mmHg) compared to both young (12.8±2.8ms/mmHg; p<0.001) and middle-aged/older men with normal testosterone (8.6±4.4ms/mmHg; p=0.046) during Phase IV of the Valsalva maneuver. There were no differences in oxidized LDL, (p=0.882) or TAS across groups (p=0.633). IL-6 was significantly higher in middle-aged/older men with low testosterone compared to the other groups (p<0.05 for all) and inversely correlated with cBRS (r=-0.594, p=0.007). Middle-aged/older men had reduced carotid artery compliance compared to young, regardless of testosterone status (p<0.001). CONCLUSIONS These observations indicate that low testosterone in middle-aged/older men may contribute to a reduction in cBRS; increased inflammation may also contribute to a reduction in cBRS.
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Affiliation(s)
- Matthew C Babcock
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Veterans Affairs Eastern Colorado Geriatric Research, Educational and Clinical Center, Denver, CO, United States
| | - Lyndsey E DuBose
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Veterans Affairs Eastern Colorado Geriatric Research, Educational and Clinical Center, Denver, CO, United States
| | - Kerry L Hildreth
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Brian L Stauffer
- Division of Cardiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Division of Cardiology, Denver Health Medical Center, Denver, CO, United States
| | - William K Cornwell
- Division of Cardiology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Wendy M Kohrt
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Veterans Affairs Eastern Colorado Geriatric Research, Educational and Clinical Center, Denver, CO, United States
| | - Kerrie L Moreau
- Division of Geriatric Medicine, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States.,Veterans Affairs Eastern Colorado Geriatric Research, Educational and Clinical Center, Denver, CO, United States
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Ramesh S, James MT, Holroyd‐Leduc JM, Wilton SB, Sola DY, Ahmed SB. Heart rate variability as a function of menopausal status, menstrual cycle phase, and estradiol level. Physiol Rep 2022; 10:e15298. [PMID: 35608101 PMCID: PMC9127980 DOI: 10.14814/phy2.15298] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/17/2022] [Accepted: 04/22/2022] [Indexed: 05/15/2023] Open
Abstract
Low estradiol status is associated with increased cardiovascular risk. We sought to determine the association between heart rate variability (HRV), a marker of cardiovascular risk, at baseline and in response to stressor as a function of menopausal status, menstrual cycle phase and estradiol level. Forty-one healthy women (13 postmenopausal, 28 premenopausal) were studied. Eleven premenopausal women were additionally studied in the high and low estradiol phases of the menstrual cycle. HRV was calculated by spectral power analysis (low Frequency (LF), high frequency (HF) and LF:HF) at baseline and in response to graded Angiotensin II (AngII) infusion. The primary outcomes were differences in HRV at baseline and in response to AngII. Compared to premenopausal women in the low estradiol phase, postmenopausal women demonstrated lower baseline LF (p = 0.01) and HF (p < 0.001) measures, which were not significant after adjustment for age and BMI. In response to AngII, a decrease in cardioprotective HRV (ΔHF = -0.43 ± 0.46 ln ms2 , p = 0.005 vs. baseline) was observed in postmenopausal women versus premenopausal women. Baseline HRV parameters did not differ by menstrual phase in premenopausal women. During the low estradiol phase, no differences were observed in the HRV response to AngII challenge. In contrast, women in the high estradiol phase were unable to maintain HRV (ΔLF = -0.07 ± 0.46 ln ms2 , p = 0.048 response vs. baseline, ΔHF = -0.33 ± 0.74 ln ms2, p = 0.048 response vs. baseline). No association was observed between any measure of HRV and estradiol level. Menopausal status and the high estradiol phase in premenopausal women were associated with reduced HRV, a marker of cardiovascular risk. Understanding the role of estradiol in the modulation of cardiac autonomic tone may help guide risk reduction strategies in women.
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Affiliation(s)
- Sharanya Ramesh
- Temerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
| | - Matthew T. James
- Temerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
- Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
- Libin Cardiovascular InstituteCalgaryAlbertaCanada
| | | | - Stephen B. Wilton
- Temerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
- Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
| | - Darlene Y Sola
- Temerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
| | - Sofia B. Ahmed
- Temerty Faculty of MedicineUniversity of TorontoTorontoOntarioCanada
- Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada
- Libin Cardiovascular InstituteCalgaryAlbertaCanada
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Barnett AM, Babcock MC, Watso JC, Migdal KU, Gutiérrez OM, Farquhar WB, Robinson AT. High dietary salt intake increases urinary NGAL excretion and creatinine clearance in healthy young adults. Am J Physiol Renal Physiol 2022; 322:F392-F402. [PMID: 35157527 PMCID: PMC8934673 DOI: 10.1152/ajprenal.00240.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 02/02/2022] [Accepted: 02/11/2022] [Indexed: 11/22/2022] Open
Abstract
In rodents and older patients with elevated blood pressure (BP), high dietary sodium increases excretion of biomarkers of kidney injury, but it is unclear whether this effect occurs in healthy young adults. The purpose of this study was to determine whether short-term high dietary salt increases urinary excretion of the kidney injury biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in healthy young adults. Twenty participants participated in a double-blind, placebo-controlled, randomized crossover study. For 10 days each, participants were asked to consume salt (3,900 mg sodium) or placebo capsules. We measured BP during each visit, obtained 24-h urine samples for measurements of electrolytes, NGAL, and KIM-1, and assessed creatinine clearance. Compared with placebo, salt loading increased daily urinary sodium excretion (placebo: 130.3 ± 62.4 mmol/24 h vs. salt: 287.2 ± 72.0 mmol/24 h, P < 0.01). There was no difference in mean arterial BP (placebo: 77 ± 7 mmHg vs. salt: 77 ± 6 mmHg, P = 0.83) between conditions. However, salt loading increased the urinary NGAL excretion rate (placebo: 59.8 ± 44.4 ng/min vs. salt: 80.8 ± 49.5 ng/min, P < 0.01) and increased creatinine clearance (placebo: 110.5 ± 32.9 mL/min vs. salt: 145.0 ± 24.9 mL/min, P < 0.01). Urinary KIM-1 excretion was not different between conditions. In conclusion, in healthy young adults 10 days of dietary salt loading increased creatinine clearance and increased urinary excretion of the kidney injury biomarker marker NGAL but not KIM-1.NEW & NOTEWORTHY In healthy young adults, 10 days of dietary salt loading increased creatinine clearance and increased urinary excretion of the kidney injury biomarker marker neutrophil gelatinase-associated lipocalin despite no change in resting blood pressure.
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Affiliation(s)
- Alex M Barnett
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama
| | - Matthew C Babcock
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
- Division of Geriatric Medicine, University of Colorado-Anschutz Medical Campus, Aurora, Colorado
| | - Joseph C Watso
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Kamila U Migdal
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
- War Related Illness and Injury Study Center, Washington DC Department of Veteran Affairs Medical Center, Washington, District of Columbia
| | - Orlando M Gutiérrez
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Austin T Robinson
- Neurovascular Physiology Laboratory, School of Kinesiology, Auburn University, Auburn, Alabama
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Becker BK, Johnston JG, Young CM, Torres Rodriguez AA, Jin C, Pollock DM. Endothelin B receptors impair baroreflex function and increase blood pressure variability during high salt diet. Auton Neurosci 2021; 232:102796. [PMID: 33798837 PMCID: PMC8040376 DOI: 10.1016/j.autneu.2021.102796] [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: 07/16/2020] [Revised: 03/01/2021] [Accepted: 03/04/2021] [Indexed: 10/21/2022]
Abstract
Baroreflex function is an integral component maintaining consistent blood pressure. Hypertension is often associated with baroreflex dysfunction, and environmental risk factors such as high salt diet exacerbate hypertension in subjects with baroreflex dysfunction. However, the interactions between high salt diet, baroreflex dysfunction, and hypertension are incompletely understood. The endothelin system is another potent mediator of blood pressure control especially in response to a high salt diet. We hypothesized that the endothelin B (ETB) receptor activation on adrenergic nerves decreases baroreflex sensitivity. We utilized male ETB receptor deficient (ETB-def) rats that express functional ETB receptors only on adrenergic nerves and transgenic (TG) controls to evaluate baroreflex function during normal (0.49% NaCl) and high (4.0% NaCl) salt diets. In conscious rats equipped with telemetry, ETB-def rats had an increased lability of systolic blood pressure (SBP) compared to TG controls as indicated by higher standard deviation (SD) of SBP under both normal (10.2 ± 0.6 vs. 12.4 ± 0.9 mmHg, respectively, p = 0.0001) and high (11.7 ± 0.6 vs. 16.1 ± 1.0 mmHg, p = 0.0001) salt diets. In anesthetized preparations, ETB-def rats displayed reduced heart rate (p genotype = 0.0167) and renal sympathetic nerve (p genotype = 0.0022) baroreflex sensitivity. We then gave male Sprague-Dawley rats the selective ETB receptor antagonist, A-192621 (10 mg/kg/day), to block ETB receptors. Following ETB receptor antagonism, even though SBP increased (131 ± 7 before vs. 152 ± 8 mmHg after, p < 0.0001), the lability (standard deviation) of SBP decreased (9.3 ± 2.0 vs. 7.1 ± 1.1 mmHg, p = 0.0155). These data support our hypothesis that ETB receptors on adrenergic nerves contribute to baroreflex dysfunction.
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Affiliation(s)
- Bryan K Becker
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America.
| | - Jermaine G Johnston
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Carolyn M Young
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Alfredo A Torres Rodriguez
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - Chunhua Jin
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
| | - David M Pollock
- Cardio-Renal Physiology and Medicine, Department of Medicine, Division of Nephrology, University of Alabama at Birmingham, Birmingham, AL 35294, United States of America
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9
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Chapman CL, Reed EL, Worley ML, Pietrafesa LD, Kueck PJ, Bloomfield AC, Schlader ZJ, Johnson BD. Sugar-sweetened soft drink consumption acutely decreases spontaneous baroreflex sensitivity and heart rate variability. Am J Physiol Regul Integr Comp Physiol 2021; 320:R641-R652. [PMID: 33533320 DOI: 10.1152/ajpregu.00310.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In healthy humans, fructose-sweetened water consumption increases blood pressure variability (BPV) and decreases spontaneous cardiovagal baroreflex sensitivity (cBRS) and heart rate variability (HRV). However, whether consuming commercially available soft drinks containing high levels of fructose elicits similar responses is unknown. We hypothesized that high-fructose corn syrup (HFCS)-sweetened soft drink consumption increases BPV and decreases cBRS and HRV to a greater extent compared with artificially sweetened (diet) and sucrose-sweetened (sucrose) soft drinks and water. Twelve subjects completed four randomized, double-blinded trials in which they drank 500 mL of water or commercially available soft drinks matched for taste and caffeine content. We continuously measured beat-to-beat blood pressure (photoplethysmography) and R-R interval (ECG) before and 30 min after drink consumption during supine rest for 5 min during spontaneous and paced breathing. BPV was evaluated using standard deviation (SD), average real variability (ARV), and successive variation (SV) methods for systolic and diastolic blood pressure. cBRS was assessed using the sequence method. HRV was evaluated using the root mean square of successive differences (RMSSD) in R-R interval. There were no differences between conditions in the magnitude of change from baseline in SD, ARV, and SV (P ≥ 0.07). There were greater reductions in cBRS during spontaneous breathing in the HFCS (-3 ± 5 ms/mmHg) and sucrose (-3 ± 5 ms/mmHg) trials compared with the water trial (+1 ± 5 ms/mmHg, P < 0.03). During paced breathing, HFCS evoked greater reductions in RMSSD compared with water (-26 ± 34 vs. +2 ± 26 ms, P < 0.01). These findings suggest that sugar-sweetened soft drink consumption alters cBRS and HRV but not BPV.
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Affiliation(s)
- Christopher L Chapman
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.,Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Emma L Reed
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.,Department of Human Physiology, University of Oregon, Eugene, Oregon
| | - Morgan L Worley
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, Indiana
| | - Leonard D Pietrafesa
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Paul J Kueck
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Adam C Bloomfield
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York
| | - Zachary J Schlader
- Department of Kinesiology, School of Public Health, Indiana University, Bloomington, Indiana
| | - Blair D Johnson
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, New York.,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, Indiana
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10
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Zhang W, Xu JZ, Lu XH, Li H, Wang D, Wang JG. Ambulatory blood pressure in relation to interaction between dietary sodium intake and serum uric acid in the young. Blood Press 2020; 30:60-66. [PMID: 33030062 DOI: 10.1080/08037051.2020.1829458] [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: 10/23/2022]
Abstract
PURPOSE We hypothesise that dietary sodium intake interacts with serum uric acid to influence blood pressure (BP) in children and adolescents. In the present study, we investigated ambulatory BP in relation to hyperuricaemia, dietary sodium intake and their interaction in children and adolescents with hypertension. MATERIALS AND METHODS A total of 616 study participants were 10-24 years old and had primary hypertension diagnosed after admission in a specialised inpatient ward. Ambulatory BP monitoring was performed during hospitalisation. 24-h urine was collected for measurements of electrolytes. Hyperuricaemia was defined as a serum uric acid of ≥327.25 μmol/L in patients <18 years old and of ≥420 and ≥360 μmol/L, respectively, in male and female patients ≥18 years old. RESULTS In adjusted analyses, patients with hyperuricaemia (n = 283), compared with those with normal serum uric acid, had similar 24-h systolic BP (131.7 mmHg, p = 0.54) and a significantly (p ≤ 0.005) lower 24-h diastolic BP (77.5 vs. 80.9 mmHg) and higher 24-h pulse pressure (54.2 vs. 51.7 mmHg). In similar adjusted analyses, 24-h ambulatory pulse pressure, but not systolic/diastolic BP (p ≥ 0.12), significantly differed across the quartile distributions of urinary sodium excretion (p for trend ≤ 0.04). Further adjusted analyses showed significant (p ≤ 0.04) interaction between serum uric acid and urinary sodium excretion in relation to 24-h systolic BP. In patients with hyperuricaemia (p = 0.04), but not those with normal serum uric acid (p = 0.13), 24-h systolic BP was significantly associated with urinary sodium excretion, with a 6.5 ± 2.1 mmHg difference between quartiles 4 and 1. Similar results were observed for daytime and night-time BP and pulse pressure. CONCLUSIONS Both hyperuricaemia and higher dietary sodium intake were associated with higher pulse pressure, and their interaction further heightened systolic BP.
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Affiliation(s)
- Wei Zhang
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jian-Zhong Xu
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao-Hong Lu
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hua Li
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Dian Wang
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ji-Guang Wang
- Department of Cardiovascular Medicine, Centre for Epidemiological Studies and Clinical Trials, Shanghai Key Laboratory of Hypertension, The Shanghai Institute of Hypertension, Shanghai, China.,Department of Hypertension, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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11
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Overwyk KJ, Quader ZS, Maalouf J, Bates M, Webster J, George MG, Merritt RK, Cogswell ME. Dietary Sodium Intake and Health Indicators: A Systematic Review of Published Literature between January 2015 and December 2019. Adv Nutr 2020; 11:1174-1200. [PMID: 32449929 PMCID: PMC7490163 DOI: 10.1093/advances/nmaa049] [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: 02/13/2020] [Revised: 03/26/2020] [Accepted: 04/01/2020] [Indexed: 12/29/2022] Open
Abstract
As the science surrounding population sodium reduction evolves, monitoring and evaluating new studies on intake and health can help increase our understanding of the associated benefits and risks. Here we describe a systematic review of recent studies on sodium intake and health, examine the risk of bias (ROB) of selected studies, and provide direction for future research. Seven online databases were searched monthly from January 2015 to December 2019. We selected human studies that met specified population, intervention, comparison, outcome, time, setting/study design (PICOTS) criteria and abstracted attributes related to the study population, design, intervention, exposure, and outcomes, and evaluated ROB for the subset of studies on sodium intake and cardiovascular disease risks or indicators. Of 41,601 abstracts reviewed, 231 studies were identified that met the PICOTS criteria and ROB was assessed for 54 studies. One hundred and fifty-seven (68%) studies were observational and 161 (70%) focused on the general population. Five types of sodium interventions and a variety of urinary and dietary measurement methods were used to establish and quantify sodium intake. Five observational studies used multiple 24-h urine collections to assess sodium intake. Evidence mainly focused on cardiovascular-related indicators (48%) but encompassed an assortment of outcomes. Studies varied in ROB domains and 87% of studies evaluated were missing information on ≥1 domains. Two or more studies on each of 12 outcomes (e.g., cognition) not previously included in systematic reviews and 9 new studies at low ROB suggest the need for ongoing or updated systematic reviews of evidence on sodium intake and health. Summarizing evidence from assessments on sodium and health outcomes was limited by the various methods used to measure sodium intake and outcomes, as well as lack of details related to study design and conduct. In line with research recommendations identified by the National Academies of Science, future research is needed to identify and standardize methods for measuring sodium intake.
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Affiliation(s)
- Katherine J Overwyk
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
- IHRC, Inc. Atlanta, GA, USA
| | - Zerleen S Quader
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
- IHRC, Inc. Atlanta, GA, USA
| | - Joyce Maalouf
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
| | - Marlana Bates
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
- Oak Ridge Institute for Science and Education, Oak Ridge, TN, USA
| | - Jacqui Webster
- The George Institute for Global Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Mary G George
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
| | - Robert K Merritt
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
| | - Mary E Cogswell
- Division for Heart Disease and Stroke Prevention, CDC, Atlanta, GA, USA
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12
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Babcock MC, Robinson AT, Migdal KU, Watso JC, Martens CR, Edwards DG, Pescatello LS, Farquhar WB. High Salt Intake Augments Blood Pressure Responses During Submaximal Aerobic Exercise. J Am Heart Assoc 2020; 9:e015633. [PMID: 32406312 PMCID: PMC7660875 DOI: 10.1161/jaha.120.015633] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background High sodium (Na+) intake is a widespread cardiovascular disease risk factor. High Na+ intake impairs endothelial function and exaggerates sympathetic reflexes, which may augment exercising blood pressure (BP) responses. Therefore, this study examined the influence of high dietary Na+ on BP responses during submaximal aerobic exercise. Methods and Results Twenty adults (8F/12M, age=24±4 years; body mass index 23.0±0.6 kg·m−2; VO2peak=39.7±9.8 mL·min−1·kg−1; systolic BP=111±10 mm Hg; diastolic BP=64±8 mm Hg) participated in this randomized, double‐blind, placebo‐controlled crossover study. Total Na+ intake was manipulated via ingestion of capsules containing either a placebo (dextrose) or table salt (3900 mg Na+/day) for 10 days each, separated by ≥2 weeks. On day 10 of each intervention, endothelial function was assessed via flow‐mediated dilation followed by BP measurement at rest and during 50 minutes of cycling at 60% VO2peak. Throughout exercise, BP was assessed continuously via finger photoplethysmography and every 5 minutes via auscultation. Venous blood samples were collected at rest and during the final 10 minutes of exercise for assessment of norepinephrine. High Na+ intake increased urinary Na+ excretion (placebo=140±68 versus Na+=282±70 mmol·24H−1; P<0.001) and reduced flow‐mediated dilation (placebo=7.2±2.4 versus Na+=4.2±1.7%; P<0.001). Average exercising systolic BP was augmented following high Na+ (placebo=Δ30.0±16.3 versus Na+=Δ38.3±16.2 mm Hg; P=0.03) and correlated to the reduction in flow‐mediated dilation (R=−0.71, P=0.002). Resting norepinephrine concentration was not different between conditions (P=0.82). Norepinephrine increased during exercise (P=0.002), but there was no Na+ effect (P=0.26). Conclusions High dietary Na+ augments BP responses during submaximal aerobic exercise, which may be mediated, in part, by impaired endothelial function.
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Affiliation(s)
- Matthew C Babcock
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE
| | - Austin T Robinson
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE.,School of Kinesiology Auburn University Auburn AL
| | - Kamila U Migdal
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE
| | - Joseph C Watso
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE
| | | | - David G Edwards
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE
| | | | - William B Farquhar
- Department of Kinesiology and Applied Physiology University of Delaware Newark DE
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13
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Migdal KU, Babcock MC, Robinson AT, Watso JC, Wenner MM, Stocker SD, Farquhar WB. The Impact of High Dietary Sodium Consumption on Blood Pressure Variability in Healthy, Young Adults. Am J Hypertens 2020; 33:422-429. [PMID: 32006422 DOI: 10.1093/ajh/hpaa014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/06/2020] [Accepted: 01/31/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND High sodium (Na+) intake augments blood pressure variability (BPV) in normotensive rodents, without changes in resting blood pressure (BP). Augmented BPV is associated with end-organ damage and cardiovascular morbidity. It is unknown if changes in dietary Na+ influence BPV in humans. We tested the hypothesis that high Na+ feeding would augment BPV in healthy adults. METHODS Twenty-one participants (10 F/11 M; 26 ± 5 years; BP: 113 ± 11/62 ± 7 mm Hg) underwent a randomized, controlled feeding study that consisted of 10 days of low (2.6 g/day), medium (6.0 g/day), and high (18.0 g/day) salt diets. On the ninth day of each diet, 24-h urine samples were collected and BPV was calculated from 24-h ambulatory BP monitoring. On the tenth day, in-laboratory beat-to-beat BPV was calculated during 10 min of rest. Serum electrolytes were assessed. We calculated average real variability (ARV) and standard deviation (SD) as metrics of BPV. As a secondary analysis, we calculated central BPV from the 24-h ambulatory BP monitoring. RESULTS 24-h urinary Na+ excretion (low = 41 ± 24, medium = 97 ± 43, high = 265 ± 92 mmol/24 h, P < 0.01) and serum Na+ (low = 140.0 ± 2.1, medium = 140.7 ± 2.7, high = 141.7 ± 2.5 mmol/l, P = 0.009) increased with greater salt intake. 24-h ambulatory ARV (systolic BP ARV: low = 9.5 ± 1.7, medium = 9.5 ± 1.2, high = 10.0 ± 1.9 mm Hg, P = 0.37) and beat-to-beat ARV (systolic BP ARV: low = 2.1 ± 0.6, medium = 2.0 ± 0.4, high = 2.2 ± 0.8 mm Hg, P = 0.46) were not different. 24-h ambulatory SD (systolic BP: P = 0.29) and beat-to-beat SD (systolic BP: P = 0.47) were not different. There was a trend for a main effect of the diet (P = 0.08) for 24-h ambulatory central systolic BPV. CONCLUSIONS Ten days of high sodium feeding does not augment peripheral BPV in healthy, adults. CLINICAL TRIALS REGISTRATION NCT02881515.
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Affiliation(s)
- Kamila U Migdal
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
| | - Matthew C Babcock
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Austin T Robinson
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
- School of Kinesiology, Neurovascular Physiology Laboratory, Auburn University, Auburn, Alabama, USA
| | - Joseph C Watso
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Megan M Wenner
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
| | - Sean D Stocker
- Department of Medicine, Division of Renal-Electrolyte, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - William B Farquhar
- Department of Kinesiology & Applied Physiology, University of Delaware, Newark, Delaware, USA
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14
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Baqar S, Kong YW, Chen AX, O'Callaghan C, MacIsaac RJ, Bouterakos M, Lambert GW, Jerums G, Lambert EE, Ekinci EI. Effect of Salt Supplementation on Sympathetic Activity and Endothelial Function in Salt-Sensitive Type 2 Diabetes. J Clin Endocrinol Metab 2020; 105:5639695. [PMID: 31761946 DOI: 10.1210/clinem/dgz219] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 11/23/2019] [Indexed: 12/22/2022]
Abstract
CONTEXT Lower sodium intake is paradoxically associated with higher mortality in type 2 diabetes (T2D). OBJECTIVE To determine whether sympathetic nervous system (SNS) activation and endothelial dysfunction contribute to these observations, we examined the effect of salt supplementation on these systems in people with T2D with habitual low sodium. We hypothesized that salt supplementation would lower SNS activity and improve endothelial function compared to placebo. DESIGN We conducted a randomized, double-blinded, placebo-controlled crossover trial. SETTING The study took place in a tertiary referral diabetes outpatient clinic. PARTICIPANTS Twenty-two people with T2D with habitual low sodium intake (24-hour urine sodium <150 mmol/24h) were included. INTERVENTION Salt supplementation (100 mmol NaCl/24h) or placebo for 3 weeks was administered. MAIN OUTCOME MEASURES The primary outcome of SNS activity and endothelial function was assessed as follows: Microneurography assessed muscle sympathetic nerve activity (MSNA), pulse amplitude tonometry assessed endothelial function via reactive hyperemic index (RHI), and arterial stiffness was assessed via augmentation index (AI). Secondary outcomes included cardiac baroreflex, serum aldosterone, ambulatory blood pressure monitoring (ABPM), heart rate variability (HRV), and salt sensitivity. RESULTS Compared to placebo, salt supplementation increased MSNA (burst frequency P = .047, burst incidence P = .016); however, RHI (P = .24), AI (P = .201), ABPM (systolic P = .09, diastolic P = .14), and HRV were unaffected. Salt supplementation improved baroreflex (slope P = .026) and lowered aldosterone (P = .004), and in salt-resistant individuals there was a trend toward improved RHI (P = .07). CONCLUSIONS In people with T2D and low habitual sodium intake, salt supplementation increased SNS activity without altering endothelial function or blood pressure but improved baroreflex function, a predictor of cardiac mortality. Salt-resistant individuals trended toward improved endothelial function with salt supplementation.
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Affiliation(s)
- Sara Baqar
- Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Yee Wen Kong
- Department of Medicine, Austin Health, Heidelberg, Victoria, Australia
| | - Angela X Chen
- Department of Medicine, Austin Health, Heidelberg, Victoria, Australia
| | | | - Richard J MacIsaac
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
- Department of Endocrinology & Diabetes, St Vincent's Hospital Melbourne and The University of Melbourne, Fitzroy, Victoria, Australia
| | - Maree Bouterakos
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Gavin W Lambert
- Human Neurotransmitters Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Iverson Health Innovation Research Institute and Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - George Jerums
- Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
| | - Elisabeth E Lambert
- Human Neurotransmitters Laboratory, Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia
- Iverson Health Innovation Research Institute and Faculty of Health, Arts and Design, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Elif I Ekinci
- Department of Endocrinology, Austin Health, Heidelberg, Victoria, Australia
- Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
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15
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Babcock MC, Robinson AT, Watso JC, Migdal KU, Martens CR, Edwards DG, Pescatello LS, Farquhar WB. Salt Loading Blunts Central and Peripheral Postexercise Hypotension. Med Sci Sports Exerc 2020; 52:935-943. [PMID: 31609296 PMCID: PMC7144834 DOI: 10.1249/mss.0000000000002187] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
INTRODUCTION High salt intake is a widespread cardiovascular risk factor with systemic effects. These effects include an expansion of plasma volume, which may interfere with postexercise hypotension (PEH). However, the effects of high salt intake on central and peripheral indices of PEH remain unknown. We tested the hypothesis that high salt intake would attenuate central and peripheral PEH. METHODS Nineteen healthy adults (7 female/12 male; age, 25 ± 4 yr; body mass index, 23.3 ± 2.2 kg·m; V[Combining Dot Above]O2peak, 41.6 ± 8.7 mL·min·kg; systolic blood pressure (BP), 112 ± 9 mm Hg; diastolic BP, 65 ± 9 mm Hg) participated in this double-blind, randomized, placebo-controlled crossover study. Participants were asked to maintain a 2300 mg·d sodium diet for 10 d on two occasions separated by ≥2 wk. Total salt intake was manipulated via ingestion of capsules containing either table salt (3900 mg·d) or placebo (dextrose) during each diet. On the 10th day, participants completed 50 min of cycling at 60% V[Combining Dot Above]O2peak. A subset of participants (n = 8) completed 60 min of seated rest (sham trial). Beat-to-beat BP was measured in-laboratory for 60 min after exercise via finger photoplethysmography. Brachial and central BPs were measured for 24 h after exercise via ambulatory BP monitor. RESULTS Ten days of high salt intake increased urinary sodium excretion (134 ± 70 (dextrose) vs 284 ± 74 mmol per 24 h (salt), P < 0.001), expanded plasma volume (7.2% ± 10.8%), and abolished PEH during in-laboratory BP monitoring (main effect of diet, P < 0.001). Ambulatory systolic BPs were higher for 12 h after exercise during the salt and sham trials compared with the dextrose trial (average change, 3.6 ± 2.1 mm Hg (dextrose), 9.9 ± 1.4 mm Hg (salt), 9.8 ± 2.5 mm Hg (sham); P = 0.01). Ambulatory central systolic BP was also higher during the salt trial compared with dextrose trial. CONCLUSION High salt intake attenuates peripheral and central PEH, potentially reducing the beneficial cardiovascular effects of acute aerobic exercise.
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Affiliation(s)
- Matthew C. Babcock
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | - Austin T. Robinson
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | - Joseph C. Watso
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | - Kamila U. Migdal
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | | | - David G. Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
| | | | - William B. Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE
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16
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Huang L, Trieu K, Yoshimura S, Neal B, Woodward M, Campbell NRC, Li Q, Lackland DT, Leung AA, Anderson CAM, MacGregor GA, He FJ. Effect of dose and duration of reduction in dietary sodium on blood pressure levels: systematic review and meta-analysis of randomised trials. BMJ 2020; 368:m315. [PMID: 32094151 PMCID: PMC7190039 DOI: 10.1136/bmj.m315] [Citation(s) in RCA: 208] [Impact Index Per Article: 52.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/08/2020] [Indexed: 01/29/2023]
Abstract
OBJECTIVE To examine the dose-response relation between reduction in dietary sodium and blood pressure change and to explore the impact of intervention duration. DESIGN Systematic review and meta-analysis following PRISMA guidelines. DATA SOURCES Ovid MEDLINE(R), EMBASE, and Cochrane Central Register of Controlled Trials (Wiley) and reference lists of relevant articles up to 21 January 2019. INCLUSION CRITERIA Randomised trials comparing different levels of sodium intake undertaken among adult populations with estimates of intake made using 24 hour urinary sodium excretion. DATA EXTRACTION AND ANALYSIS Two of three reviewers screened the records independently for eligibility. One reviewer extracted all data and the other two reviewed the data for accuracy. Reviewers performed random effects meta-analyses, subgroup analyses, and meta-regression. RESULTS 133 studies with 12 197 participants were included. The mean reductions (reduced sodium v usual sodium) of 24 hour urinary sodium, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were 130 mmol (95% confidence interval 115 to 145, P<0.001), 4.26 mm Hg (3.62 to 4.89, P<0.001), and 2.07 mm Hg (1.67 to 2.48, P<0.001), respectively. Each 50 mmol reduction in 24 hour sodium excretion was associated with a 1.10 mm Hg (0.66 to 1.54; P<0.001) reduction in SBP and a 0.33 mm Hg (0.04 to 0.63; P=0.03) reduction in DBP. Reductions in blood pressure were observed in diverse population subsets examined, including hypertensive and non-hypertensive individuals. For the same reduction in 24 hour urinary sodium there was greater SBP reduction in older people, non-white populations, and those with higher baseline SBP levels. In trials of less than 15 days' duration, each 50 mmol reduction in 24 hour urinary sodium excretion was associated with a 1.05 mm Hg (0.40 to 1.70; P=0.002) SBP fall, less than half the effect observed in studies of longer duration (2.13 mm Hg; 0.85 to 3.40; P=0.002). Otherwise, there was no association between trial duration and SBP reduction. CONCLUSIONS The magnitude of blood pressure lowering achieved with sodium reduction showed a dose-response relation and was greater for older populations, non-white populations, and those with higher blood pressure. Short term studies underestimate the effect of sodium reduction on blood pressure. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42019140812.
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Affiliation(s)
- Liping Huang
- Sydney School of Public Health, University of Sydney, Sydney, NSW, Australia
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
| | - Kathy Trieu
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
| | - Sohei Yoshimura
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
- National Cerebral and Cardiovascular Centre, Osaka, Japan
| | - Bruce Neal
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
- Department of Epidemiology and Biostatistics, Imperial College London, London, UK
| | - Mark Woodward
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
- The George Institute for Global Health, University of Oxford, Oxford, UK
| | - Norm R C Campbell
- Departments of Medicine and Community Health Science, University of Calgary, Calgary, AB, Canada
| | - Qiang Li
- The George Institute for Global Health, UNSW Sydney, Sydney, NSW, Australia
| | | | - Alexander A Leung
- Departments of Medicine and Community Health Science, University of Calgary, Calgary, AB, Canada
| | | | - Graham A MacGregor
- Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 4NS, UK
| | - Feng J He
- Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London E1 4NS, UK
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Watso JC, Robinson AT, Babcock MC, Migdal KU, Wenner MM, Stocker SD, Farquhar WB. Short-term water deprivation does not increase blood pressure variability or impair neurovascular function in healthy young adults. Am J Physiol Regul Integr Comp Physiol 2019; 318:R112-R121. [PMID: 31617739 DOI: 10.1152/ajpregu.00149.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
High dietary salt increases arterial blood pressure variability (BPV) in salt-resistant, normotensive rodents and is thought to result from elevated plasma [Na+] sensitizing central sympathetic networks. Our purpose was to test the hypothesis that water deprivation (WD)-induced elevations in serum [Na+] augment BPV via changes in baroreflex function and sympathetic vascular transduction in humans. In a randomized crossover fashion, 35 adults [17 female/18 male, age: 25 ± 4 yr, systolic/diastolic blood pressure (BP): 107 ± 11/60 ± 7 mmHg, body mass index: 23 ± 3 kg/m2] completed two hydration protocols: a euhydration control condition (CON) and a stepwise reduction in water intake over 3 days, concluding with 16 h of WD. We assessed blood and urine electrolyte concentrations and osmolality, resting muscle sympathetic nerve activity (MSNA; peroneal microneurography; 18 paired recordings), beat-to-beat BP (photoplethysmography), common femoral artery blood flow (Doppler ultrasound), and heart rate (single-lead ECG). A subset of participants (n = 25) underwent ambulatory BP monitoring during day 3 of each protocol. We calculated average real variability as an index of BPV. WD increased serum [Na+] (141.0 ± 2.3 vs. 142.1 ± 1.7 mmol/L, P < 0.01) and plasma osmolality (288 ± 4 vs. 292 ± 5 mosmol/kg H2O, P < 0.01). However, WD did not increase beat-to-beat (1.9 ± 0.4 vs. 1.8 ± 0.4 mmHg, P = 0.24) or ambulatory daytime (9.6 ± 2.1 vs. 9.4 ± 3.3 mmHg, P = 0.76) systolic BPV. Additionally, sympathetic baroreflex sensitivity (P = 0.20) and sympathetic vascular transduction were not different after WD (P = 0.17 for peak Δmean BP following spontaneous MSNA bursts). These findings suggest that, despite modestly increasing serum [Na+], WD does not affect BPV, arterial baroreflex function, or sympathetic vascular transduction in healthy young adults.
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Affiliation(s)
- Joseph C Watso
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Austin T Robinson
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Matthew C Babcock
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Kamila U Migdal
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Sean D Stocker
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
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Abstract
PURPOSE OF REVIEW Excess sodium from dietary salt (NaCl) is linked to elevations in blood pressure (BP). However, salt sensitivity of BP varies widely between individuals and there are data suggesting that salt adversely affects target organs, irrespective of BP. RECENT FINDINGS High dietary salt has been shown to adversely affect the vasculature, heart, kidneys, skin, brain, and bone. Common mediators of the target organ dysfunction include heightened inflammation and oxidative stress. These physiological alterations may contribute to disease development over time. Despite the adverse effects of salt on BP and several organ systems, there is controversy surrounding lower salt intakes and cardiovascular outcomes. Our goal here is to review the physiology contributing to BP-independent effects of salt and address the controversy around lower salt intakes and cardiovascular outcomes. We will also address the importance of background diet in modulating the effects of dietary salt.
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Affiliation(s)
- Austin T Robinson
- Department of Kinesiology and Applied Physiology, University of Delaware, 540 South College Avenue, 201M, Newark, DE, 19713, USA
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, 540 South College Avenue, 201M, Newark, DE, 19713, USA
| | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, 540 South College Avenue, 201M, Newark, DE, 19713, USA.
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