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Shiozawa K, Saito M, Lee JB, Seo N, Kondo H, Kashima H, Endo MY, Ishida K, Millar PJ, Katayama K. Aging in females has minimal effect on changes in celiac artery blood flow during dynamic light-intensity exercise. Am J Physiol Regul Integr Comp Physiol 2024; 327:R14-R24. [PMID: 38738294 DOI: 10.1152/ajpregu.00012.2024] [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: 01/16/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/14/2024]
Abstract
Blood flow to the active muscles and arterial blood pressure (ABP) increase during dynamic exercise, whereas blood flow to inactive organs (e.g., splanchnic organs and inactive limbs) declines. Aging leads to exaggerated ABP responses to exercise in females, but whether this is related to greater splanchnic vasoconstriction is unknown. This study sought to clarify the effect of aging in females on celiac artery blood flow during dynamic light-intensity exercise. Twelve healthy young females (YF: 20 ± 2 yr, mean ± SD) and 12 healthy older females (OF: 71 ± 4 yr) performed dynamic knee-extension and knee-flexion exercises at 30% of heart rate reserve for 4 min. The absolute changes from baseline (Δ) for mean arterial blood pressure (MAP), celiac artery mean blood flow (celMBF), and celiac vascular conductance (celVC) during exercise were calculated. ABP was measured using an automated sphygmomanometer, and celMBF was recorded by Doppler ultrasonography. The increase in MAP during exercise was greater in OF than in YF (YF: +14 ± 7 mmHg, OF: +24 ± 13 mmHg, P = 0.028). The celMBF decreased during exercise in both groups, but there was no significant difference in the response between YF and OF (YF: -93.0 ± 66.1 mL/min, OF: -89.6 ± 64.0 mL/min, P = 0.951). The celVC also decreased during exercise and remained lower than baseline during exercise. However, the response was not different between YF and OF (YF: -1.8 ± 1.0 mL/min/mmHg, OF: -1.5 ± 0.6 mL/min/mmHg, P = 0.517). These results demonstrate that aging in females has minimal influence on splanchnic artery hemodynamic responses during dynamic light-intensity exercise, suggesting that exaggerated ABP responses during exercise in OF are not due to greater splanchnic vasoconstriction.NEW & NOTEWORTHY During exercise, the splanchnic arteries vasoconstrict, contributing to blood flow redistribution and the blood pressure response. Blood pressure responses to exercise are exaggerated with aging in females; however, the physiological mechanism responsible has not been clarified. We show that celiac artery blood flow changes during light-intensity dynamic exercise do not differ with age in females. This indicates the exaggerated blood pressure to exercise with aging is likely not due to a difference in splanchnic vasoconstriction.
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Affiliation(s)
- Kana Shiozawa
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
- Japan Society for the Promotion of Science, Tokyo, Japan
| | - Mitsuru Saito
- Applied Physiology Laboratory, Toyota Technological Institute, Nagoya, Japan
| | - Jordan B Lee
- Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Natsuki Seo
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Haruna Kondo
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Hideaki Kashima
- Department of Health Science, Prefectural University of Hiroshima, Hiroshima, Japan
| | - Masako Yamaoka Endo
- Department of Health Science, Prefectural University of Hiroshima, Hiroshima, Japan
| | - Koji Ishida
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
| | - Philip J Millar
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Keisho Katayama
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
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Rudolf R, Kettelhut IC, Navegantes LCC. Sympathetic innervation in skeletal muscle and its role at the neuromuscular junction. J Muscle Res Cell Motil 2024; 45:79-86. [PMID: 38367152 PMCID: PMC11096211 DOI: 10.1007/s10974-024-09665-9] [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: 07/30/2023] [Accepted: 01/30/2024] [Indexed: 02/19/2024]
Abstract
Neuromuscular junctions are the synapses between motor neurons and skeletal muscle fibers, which mediate voluntary muscle movement. Since neuromuscular junctions are also tightly associated with the capping function of terminal Schwann cells, these synapses have been classically regarded as tripartite chemical synapses. Although evidences from sympathetic innervation of neuromuscular junctions was described approximately a century ago, the essential presence and functional relevance of sympathetic contribution to the maintenance and modulation of neuromuscular junctions was demonstrated only recently. These findings shed light on the pathophysiology of different clinical conditions and can optimize surgical and clinical treatment modalities for skeletal muscle disorders.
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Affiliation(s)
- Rüdiger Rudolf
- Center for Mass Spectrometry and Optical Spectroscopy, Mannheim University of Applied Sciences, 68163, Mannheim, Germany.
- Interdisciplinary Center for Neurosciences, Heidelberg University, 69117, Heidelberg, Germany.
- Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim Heidelberg University, 69167, Mannheim, Germany.
| | - Isis C Kettelhut
- Department of Biochemistry & Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto-SP, 14049900, Brazil
| | - Luiz Carlos C Navegantes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto-SP, 14049900, Brazil
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Benarroch E. What Is the Role of the Sympathetic System in Skeletal Muscle? Neurology 2024; 102:e209488. [PMID: 38710007 DOI: 10.1212/wnl.0000000000209488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2024] Open
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Sallam NA, Wang B, Laher I. Exercise training and vascular heterogeneity in db/db mice: evidence for regional- and duration-dependent effects. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2421-2436. [PMID: 37843589 DOI: 10.1007/s00210-023-02775-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023]
Abstract
Exercise training (ET) has several health benefits; however, our understanding of regional adaptations to ET is limited. We examined the functional and molecular adaptations to short- and long-term ET in elastic and muscular conduit arteries of db/db mice in relation to changes in cardiovascular risk factors. Diabetic mice and their controls were exercised at moderate intensity for 4 or 8 weeks. The vasodilatory and contractile responses of thoracic aortae and femoral arteries isolated from the same animals were examined. Blood and aortic samples were used to measure hyperglycemia, oxidative stress, inflammation, dyslipidemia, protein expression of SOD isoforms, COX, eNOS, and Akt. Short-term ET improved nitric oxide (NO) mediated vasorelaxation in the aortae and femoral arteries of db/db mice in parallel with increased SOD2 and SOD3 expression, reduced oxidative stress and triglycerides, and independent of weight loss, glycemia, or inflammation. Long-term ET reduced body weight in parallel with reduced systemic inflammation and improved insulin sensitivity along with increased SOD1, Akt, and eNOS expression and improved NO vasorelaxation. Exercise did not restore NOS- and COX-independent vasodilatation in femoral arteries, nor did it mitigate the hypercontractility in the aortae of db/db mice; rather ET transiently increased contractility in association with upregulated COX-2. Long-term ET differentially affected the aortae and femoral arteries contractile responses. ET improved NO-mediated vasodilation in both arteries likely due to collective systemic effects. ET did not mitigate all diabetes-induced vasculopathies. Optimization of the ET regimen can help develop comprehensive management of type 2 diabetes.
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Affiliation(s)
- Nada A Sallam
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Baohua Wang
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada
| | - Ismail Laher
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada.
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Leitão L, Campos Y, Louro H, Figueira ACC, Figueiredo T, Pereira A, Conceição A, Marinho DA, Neiva HP. Detraining and Retraining Effects from a Multicomponent Training Program on the Functional Capacity and Health Profile of Physically Active Prehypertensive Older Women. Healthcare (Basel) 2024; 12:271. [PMID: 38275551 PMCID: PMC10815818 DOI: 10.3390/healthcare12020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Resuming a physical exercise program after a period of cessation is common in older women. Monitoring the responses during this detraining (DT) and retraining (RT) may allow us to analyze how the body reacts to an increase and a reduction in physical inactivity. Therefore, we conducted a follow-up training, DT, and RT in prehypertensive older women to analyze the response to these periods. METHODS Twenty-three prehypertensive older women (EG; 68.3 ± 2.8 years; 1.61 ± 0.44 m) performed 36 weeks of the multicomponent training program (MTP) followed by twelve weeks of DT plus eight weeks of RT. Fifteen prehypertensive older women (CG; 66.3 ± 3.2 years; 1.59 ± 0.37 m) maintained their normal routine. Functional capacity (FC), lipid, and hemodynamic profile were assessed before, during 24 and 36 weeks of the MTP, after 4 and 12 weeks of DT, and after 8 weeks of RT. RESULTS After 24 weeks of the MTP, only SBP did not improve. Four weeks of DT did not affect lower body strength (30-CS), TC, or GL. Eight weeks of RT improved BP (SBP: -2.52%; ES: 0.36; p < 0.00; DBP: -1.45%; ES: 0.44; p < 0.02), handgrip strength (3.77%; ES: 0.51; p < 0.00), and 30-CS (3.17%; ES: 0.38; p < 0.04) compared with 36 weeks of the MTP. CONCLUSIONS Eight weeks of RT allowed patients to recover the benefits lost with detraining, which after only four weeks affected them negatively, and the systematic practice of exercise contributed to greater regulation of BP since 24 weeks of the MTP proved not to be enough to promote positive effects of SBP.
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Affiliation(s)
- Luís Leitão
- Sciences and Technology Department, Superior School of Education of Polytechnic Institute of Setubal, 2910-761 Setúbal, Portugal; (A.C.C.F.); (T.F.); (A.P.)
- Life Quality Research Centre, 2040-413 Rio Maior, Portugal
- Department of Sport Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal; (D.A.M.); (H.P.N.)
| | - Yuri Campos
- Post Graduate Program in Physical Education, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil;
- Study Group and Research in Neuromuscular Responses, Federal University of Lavras, Lavras 37200-900, Brazil
| | - Hugo Louro
- Department of Sport Sciences, Sport Sciences School of Rio Maior, Polytechnic Institute of Santarém, 2040-413 Santarém, Portugal; (H.L.); (A.C.)
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), 6201-001 Covilhã, Portugal
| | - Ana Cristina Corrêa Figueira
- Sciences and Technology Department, Superior School of Education of Polytechnic Institute of Setubal, 2910-761 Setúbal, Portugal; (A.C.C.F.); (T.F.); (A.P.)
- Life Quality Research Centre, 2040-413 Rio Maior, Portugal
| | - Teresa Figueiredo
- Sciences and Technology Department, Superior School of Education of Polytechnic Institute of Setubal, 2910-761 Setúbal, Portugal; (A.C.C.F.); (T.F.); (A.P.)
- Life Quality Research Centre, 2040-413 Rio Maior, Portugal
| | - Ana Pereira
- Sciences and Technology Department, Superior School of Education of Polytechnic Institute of Setubal, 2910-761 Setúbal, Portugal; (A.C.C.F.); (T.F.); (A.P.)
- Life Quality Research Centre, 2040-413 Rio Maior, Portugal
| | - Ana Conceição
- Department of Sport Sciences, Sport Sciences School of Rio Maior, Polytechnic Institute of Santarém, 2040-413 Santarém, Portugal; (H.L.); (A.C.)
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), 6201-001 Covilhã, Portugal
| | - Daniel A. Marinho
- Department of Sport Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal; (D.A.M.); (H.P.N.)
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), 6201-001 Covilhã, Portugal
| | - Henrique P. Neiva
- Department of Sport Sciences, University of Beira Interior, 6201-001 Covilhã, Portugal; (D.A.M.); (H.P.N.)
- Research Center in Sports Sciences, Health Sciences and Human Development (CIDESD), 6201-001 Covilhã, Portugal
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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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Hamasaki H, Yanai H. Association of the use of psychotropic drugs with hospitalization, cardiovascular events, and mortality in patients with type 2 diabetes: a propensity score-matched cohort study. FRONTIERS IN CLINICAL DIABETES AND HEALTHCARE 2023; 4:1181998. [PMID: 37476651 PMCID: PMC10354430 DOI: 10.3389/fcdhc.2023.1181998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 06/16/2023] [Indexed: 07/22/2023]
Abstract
Background Use of psychotropic drugs (PD) may be associated with impairment of physical function. However, few studies have assessed the impact of PD on health outcomes in patients with type 2 diabetes. This study aimed to examine the associations between psychotropic drug use and handgrip strength (HGS) and between the use of PD and hospitalization in patients with type 2 diabetes. Methods From April 2013 to December 2015, we conducted a retrospective cohort study in patients with type 2 diabetes at the National Center for Global Health and Medicine Kohnodai Hospital. Patients aged 20 years and over who can measure HGS were included. All participants received nutritional guidance regarding diet therapy for type 2 diabetes at baseline. Nonpsychotropic drug users were matched one-to-one with the PD users using propensity score matching method with respect to their baseline covariates. The differences in HGS and the number of patients who had hospitalizations during the study period were examined. By Cox proportional hazard regression analysis, the association between the use of PD and repeated hospitalizations was estimated. Results A total of 1,282 patients were enrolled and followed up for 2.36 ± 0.73 years. In the propensity score matching cohort, HGS was significantly lower (p = 0.006) in PD users than non-PD users. PD users had more hospitalizations than non-PD users. Cox proportional hazard regression analysis confirmed the association of repeated hospitalizations with the use of PD (hazard ratio = 2.138; 95% confidence interval, 1.144-3.995, p = 0.017)). In addition, HGS was significantly and inversely correlated with the number of hospitalizations (r = -0.143, p = 0.013). Conclusions The use of PD could increase the risk of repeated hospitalizations. Skeletal muscle may play a role in reducing the risk of hospitalization in patients who are treated with PD.
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Affiliation(s)
| | - Hidekatsu Yanai
- Department of Diabetes and Endocrinology, National Center for Global Health and Medicine, Kohnodai Hospital, Ichikawa, Japan
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Ehlers TS, Møller S, Hansen CC, Tamariz-Ellemann AS, Vermeulen TD, Shoemaker JK, Gliemann L, Hellsten Y. Sympathetic activity is not a main cause of blood pressure reduction with exercise training in un-medicated middle-aged/older men. Scand J Med Sci Sports 2023; 33:586-596. [PMID: 36587373 DOI: 10.1111/sms.14300] [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: 09/21/2022] [Revised: 12/01/2022] [Accepted: 12/22/2022] [Indexed: 01/02/2023]
Abstract
BACKGROUND This study tested the hypothesis that training reduces resting sympathetic activity and improves baroreflex control in both hypertensive and normotensive men but reduces blood pressure only in hypertensive men. METHODS Middle-aged/older un-medicated stage-1 hypertensive males (mean age 55 ± 3 years; n = 13) and normotensive controls (mean age 60 ± 5 years; n = 12) participated in 8 weeks of supervised high-intensity interval spinning training. Before and after training, muscle sympathetic nerve activity (MSNA) and blood pressure were measured at rest and during a sympatho-excitatory cold pressor test (CPT). Based on the measurements, baroreceptor sensitivity and baroreceptor threshold were calculated. RESULTS Resting MSNA and baroreceptor sensitivity were similar for the hypertensive and the normotensive groups. Training lowered MSNA (p < 0.05), expressed as burst frequency (burst/min), overall, and to a similar extent, in both groups (17% and 27%, respectively, in hypertensive and normotensive group), whereas blood pressure was only significantly (p < 0.05) lowered (by 4 mmHg in both systolic and diastolic pressure) in the hypertensive group. Training did not (p > 0.05) alter the MSNA or blood pressure response to CPT or increase baroreceptor sensitivity but reduced (p < 0.05) the baroreceptor threshold with a main effect for both groups. Training adherence and intensity were similar in both groups yet absolute maximal oxygen uptake increased by 15% in the normotensive group only. CONCLUSION The dissociation between the training induced changes in resting MSNA, lack of change in baroreflex sensitivity and the change in blood pressure, suggests that MSNA is not a main cause of the blood pressure reduction with exercise training in un-medicated middle-aged/older men.
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Affiliation(s)
- Thomas S Ehlers
- Department for Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Sophie Møller
- Department for Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Camilla C Hansen
- Department for Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - Lasse Gliemann
- Department for Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Department for Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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Hart DA. Sex differences in musculoskeletal injury and disease risks across the lifespan: Are there unique subsets of females at higher risk than males for these conditions at distinct stages of the life cycle? Front Physiol 2023; 14:1127689. [PMID: 37113695 PMCID: PMC10126777 DOI: 10.3389/fphys.2023.1127689] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Abstract
Sex differences have been reported for diseases of the musculoskeletal system (MSK) as well as the risk for injuries to tissues of the MSK system. For females, some of these occur prior to the onset of puberty, following the onset of puberty, and following the onset of menopause. Therefore, they can occur across the lifespan. While some conditions are related to immune dysfunction, others are associated with specific tissues of the MSK more directly. Based on this life spectrum of sex differences in both risk for injury and onset of diseases, a role for sex hormones in the initiation and progression of this risk is somewhat variable. Sex hormone receptor expression and functioning can also vary with life events such as the menstrual cycle in females, with different tissues being affected. Furthermore, some sex hormone receptors can affect gene expression independent of sex hormones and some transitional events such as puberty are accompanied by epigenetic alterations that can further lead to sex differences in MSK gene regulation. Some of the sex differences in injury risk and the post-menopausal disease risk may be "imprinted" in the genomes of females and males during development and sex hormones and their consequences only modulators of such risks later in life as the sex hormone milieu changes. The purpose of this review is to discuss some of the relevant conditions associated with sex differences in risks for loss of MSK tissue integrity across the lifespan, and further discuss several of the implications of their variable relationship with sex hormones, their receptors and life events.
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DeLorey DS, Clifford PS. Does sympathetic vasoconstriction contribute to metabolism: Perfusion matching in exercising skeletal muscle? Front Physiol 2022; 13:980524. [PMID: 36171966 PMCID: PMC9510655 DOI: 10.3389/fphys.2022.980524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/17/2022] [Indexed: 11/14/2022] Open
Abstract
The process of matching skeletal muscle blood flow to metabolism is complex and multi-factorial. In response to exercise, increases in cardiac output, perfusion pressure and local vasodilation facilitate an intensity-dependent increase in muscle blood flow. Concomitantly, sympathetic nerve activity directed to both exercising and non-active muscles increases as a function of exercise intensity. Several studies have reported the presence of tonic sympathetic vasoconstriction in the vasculature of exercising muscle at the onset of exercise that persists through prolonged exercise bouts, though it is blunted in an exercise-intensity dependent manner (functional sympatholysis). The collective evidence has resulted in the current dogma that vasoactive molecules released from skeletal muscle, the vascular endothelium, and possibly red blood cells produce local vasodilation, while sympathetic vasoconstriction restrains vasodilation to direct blood flow to the most metabolically active muscles/fibers. Vascular smooth muscle is assumed to integrate a host of vasoactive signals resulting in a precise matching of muscle blood flow to metabolism. Unfortunately, a critical review of the available literature reveals that published studies have largely focused on bulk blood flow and existing experimental approaches with limited ability to reveal the matching of perfusion with metabolism, particularly between and within muscles. This paper will review our current understanding of the regulation of sympathetic vasoconstriction in contracting skeletal muscle and highlight areas where further investigation is necessary.
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Affiliation(s)
- Darren S. DeLorey
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
- *Correspondence: Darren S. DeLorey,
| | - Philip S. Clifford
- College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, United States
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Burtscher J, Strasser B, Burtscher M, Millet GP. The Impact of Training on the Loss of Cardiorespiratory Fitness in Aging Masters Endurance Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph191711050. [PMID: 36078762 PMCID: PMC9517884 DOI: 10.3390/ijerph191711050] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 05/16/2023]
Abstract
Elite masters endurance athletes are considered models of optimal healthy aging due to the maintenance of high cardiorespiratory fitness (CRF) until old age. Whereas a drop in VO2max in masters athletes has been broadly investigated, the modifying impact of training still remains a matter of debate. Longitudinal observations in masters endurance athletes demonstrated VO2max declines between -5% and -46% per decade that were closely related to changes in training volume. Here, using regression analyses, we show that 54% and 39% of the variance in observed VO2max decline in male and female athletes, respectively is explained by changes in training volume. An almost linear VO2max decrease was observed in studies on young and older athletes, as well as non-athletes, starting a few days after training cessation, with a decline of as much as -20% after 12 weeks. Besides a decline in stroke volume and cardiac output, training cessation was accompanied by considerable reductions in citrate synthase and succinate dehydrogenase activity (reduction in mitochondrial content and oxidative capacity). This reduction could largely be rescued within similar time periods of training (re)uptake. It is evident that training reduction or cessation leads to a considerably accelerated VO2max drop, as compared to the gradual aging-related VO2max decline, which can rapidly nullify many of the benefits of preceding long-term training efforts.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Barbara Strasser
- Medical Faculty, Sigmund Freud Private University, A-1020 Vienna, Austria
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, A-6020 Innsbruck, Austria
- Correspondence:
| | - Gregoire P. Millet
- Department of Biomedical Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland
- Institute of Sport Sciences, University of Lausanne, CH-1015 Lausanne, Switzerland
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Katayama K, Saito M, Ishida K, Shimizu K, Shiozawa K, Mizuno S, Ogoh S. Sympathetic vasomotor outflow during low-intensity leg cycling in healthy older males. Exp Physiol 2022; 107:825-833. [PMID: 35749656 DOI: 10.1113/ep090497] [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] [Received: 04/08/2022] [Accepted: 06/21/2022] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Sympathetic vasomotor outflow is reduced during low-intensity dynamic leg exercise in younger individuals: does ageing influence the sympathoinhibitory effect during low-intensity leg cycling? What is the main finding and its importance? Muscle sympathetic nerve activity during low-intensity cycling decreased in older males, as seen in young males. It is possible that cardiopulmonary baroreflex-mediated inhibition of sympathetic vasomotor outflow during dynamic leg exercise is preserved in healthy older males. ABSTRACT Muscle sympathetic nerve activity (MSNA) is reduced during low-intensity dynamic leg exercise in young males. It is suggested that this inhibition is mediated by loading of the cardiopulmonary baroreceptors. The purpose of this study was to clarify the impact of age on MSNA during dynamic leg exercise. Nine younger males (YM, mean ± SD, 20 ± 1 years) and nine older males (OM, 72 ± 3 years) completed the study. The subjects performed two 4-min cycling exercises at 10% of their heart rate reserve using a cycle ergometer in a semirecumbent position (MSNA and estimated central venous pressure (eCVP) trials). MSNA was recorded via microneurography of the left radial nerve. The CVP was estimated based on peripheral venous pressure, which was monitored using a cannula in the right large antecubital vein. The magnitude of the increase in mean arterial blood pressure during leg cycling was larger in OM (+9.3 ± 5.5 mmHg) compared with YM (+2.8 ± 4.7 mmHg). MSNA burst frequency was decreased during cycling in both YM (-8.1 ± 3.8 bursts/min) and OM (-10.6 ± 3.3 bursts/min), but no significant difference was found between the two groups. The eCVP increased during exercise in both groups, and there was no difference in the changes in eCVP between YM (+1.1 ± 0.4 mmHg) and OM (+1.2 ± 0.7 mmHg). These data indicate that inhibition of sympathetic vasomotor outflow during low-intensity cycling appears in OM as seen in YM. It is possible that the muscle pump-induced loading of the cardiopulmonary baroreflex is preserved during cycling in healthy older males.
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Affiliation(s)
- Keisho Katayama
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Mitsuru Saito
- Applied Physiology Laboratory, Toyota Technological Institute, Nagoya, Japan
| | - Koji Ishida
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan.,Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Kaori Shimizu
- Faculty of Human Development, Kokugakuin University, Yokohama, Japan
| | - Kana Shiozawa
- Graduate School of Medicine, Nagoya University, Nagoya, Japan
| | - Sahiro Mizuno
- Research and Development, Hosei University, Tokyo, Japan
| | - Shigehiko Ogoh
- Department of Biomedical Engineering, Toyo University, Kawagoe, Japan
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