1
|
AlGhatrif M, Morrell CH, Fleg JL, Chantler PD, Najjar SS, Becker LC, Ferrucci L, Gerstenblith G, Lakatta EG. Longitudinal decline in peak V̇o 2 with aging in a healthy population is associated with a reduction in peripheral oxygen utilization but not in cardiac output. Am J Physiol Heart Circ Physiol 2024; 327:H509-H517. [PMID: 38874616 DOI: 10.1152/ajpheart.00665.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 05/31/2024] [Accepted: 05/31/2024] [Indexed: 06/15/2024]
Abstract
Aging is associated with a significant decline in aerobic capacity assessed by maximal exercise oxygen consumption (V̇o2max). The relative contributions of the specific V̇o2 components driving this decline, namely cardiac output (CO) and arteriovenous oxygen difference (A - V)O2, remain unclear. We examined this issue by analyzing data from 99 community-dwelling participants (baseline age: 21-96 yr old; average follow-up: 12.6 yr old) from the Baltimore Longitudinal Study of Aging, free of clinical cardiovascular disease. V̇o2peak, a surrogate of V̇o2max, was used to assess aerobic capacity during upright cycle ergometry. Peak exercise left ventricular volumes, heart rate, and CO were estimated using repeated gated cardiac blood pool scans. The Fick equation was used to calculate (A - V)O2diff,peak from COpeak and V̇o2peak. In unadjusted models, V̇o2peak, (A - V)O2diff,peak, and COpeak declined longitudinally over time at steady rates with advancing age. In multiple linear regression models adjusting for baseline values and peak workload, however, steeper declines in V̇o2peak and (A - V)O2diff,peak were observed with advanced entry age but not in COpeak. The association between the declines in V̇o2peak and (A - V)O2diff,peak was stronger among those ≥50 yr old compared with their younger counterparts, but the difference between the two age groups did not reach statistical significance. These findings suggest that age-associated impairment of peripheral oxygen utilization during maximal exercise poses a stronger limitation on peak V̇o2 than that of CO. Future studies examining interventions targeting the structure and function of peripheral muscles and their vasculature to mitigate age-associated declines in (A - V)O2diff are warranted.NEW & NOTEWORTHY The age-associated decline in aerobic exercise performance over an average of 13 yr in community-dwelling healthy individuals is more closely associated with decreased peripheral oxygen utilization rather than decreased cardiac output. This association was more evident in older than younger individuals. These findings suggest that future studies with larger samples examine whether these associations vary across the age range and whether the decline in cardiac output plays a greater role earlier in life. In addition, studies focused on determinants of peripheral oxygen uptake by exercising muscle may guide the selection of preventive strategies designed to maintain physical fitness with advancing age.
Collapse
Affiliation(s)
- Majd AlGhatrif
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States
- Longitudinal Study Section, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Christopher H Morrell
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States
| | - Jerome L Fleg
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland, United States
| | - Paul D Chantler
- Department of Exercise Physiology, West Virginia University, Morgantown, West Virginia, United States
| | - Samer S Najjar
- Department of Cardiology, MedStar Heart and Vascular Institute, MedStar Health, Baltimore, Maryland, United States
| | - Lewis C Becker
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Luigi Ferrucci
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States
| | - Gary Gerstenblith
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, United States
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Bethesda, Maryland, United States
| |
Collapse
|
2
|
Kordi N, Saydi A, Karami S, Bagherzadeh-Rahmani B, Marzetti E, Jung F, Stockwell BR. Ferroptosis and aerobic training in ageing. Clin Hemorheol Microcirc 2024; 87:347-366. [PMID: 38306027 DOI: 10.3233/ch-232076] [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] [Indexed: 02/03/2024]
Abstract
Ferroptosis is a form of programmed cell death that plays a significant role in causing several diseases such as heart attack and heart failure, through alterations in fat, amino acid, and iron metabolism. Comprehending the regulatory mechanisms of ferroptosis signaling is critical because it has a considerable effect on the elderly's mortality. Conversely, age-related changes in substrate metabolism and metabolite levels are recognized to give rise to obesity. Furthermore, research has proposed that aging and obesity-related changes in substrate metabolism may aggravate ferroptosis. The suppression of ferroptosis holds potential as a successful therapeutic approach for managing different diseases, including sarcopenia, cardiovascular diseases, and central nervous system diseases. However, the pathologic and biological mechanisms behind the function of ferroptosis are not fully comprehended yet. Physical activity could affect lipid, amino acid, and iron metabolism to modulate ferroptosis. The aim of this study is to showcase the current understanding of the molecular mechanisms leading to ferroptosis and discuss the role of aging and physical activity in this phenomenon.
Collapse
Affiliation(s)
- Negin Kordi
- Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
| | - Ali Saydi
- Department of Exercise Physiology, Faculty of Sport Sciences, Razi University, Kermanshah, Iran
| | - Sajad Karami
- Faculty of Physical Education and Sport Science, Shahid Rajaee Teacher Training University, Tehran, Iran
| | - Behnam Bagherzadeh-Rahmani
- Department of Exercise Physiology, Faculty of Sport Sciences, Hakim Sabzevari University, Sabzevar, Iran
| | - Emanuele Marzetti
- Department of Geriatrics and Orthopedics, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario "A. Gemelli" IRCCS, Rome, Italy
| | - Friedrich Jung
- Faculty of Health Sciences Brandenburg, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany
| | - Brent R Stockwell
- Department of Chemistry, Columbia University, NewYork, NY, USA
- Department of Biological Sciences, Columbia University, New York, NY, USA
| |
Collapse
|
3
|
Koch Esteves N, Khir AW, González‐Alonso J. Lower limb hyperthermia augments functional hyperaemia during small muscle mass exercise similarly in trained elderly and young humans. Exp Physiol 2023; 108:1154-1171. [PMID: 37409754 PMCID: PMC10988472 DOI: 10.1113/ep091275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/23/2023] [Indexed: 07/07/2023]
Abstract
NEW FINDINGS What is the central question of the study? Ageing is postulated to lead to underperfusion of human limb tissues during passive and exertional hyperthermia, but findings to date have been equivocal. Thus, does age have an independent adverse effect on local haemodynamics during passive single-leg hyperthermia, single-leg knee-extensor exercise and their combination? What is the main finding and its importance? Local hyperthermia increased leg blood flow over three-fold and had an additive effect during knee-extensor exercise with no absolute differences in leg perfusion between the healthy, exercise-trained elderly and the young groups. Our findings indicate that age per se does not compromise lower limb hyperaemia during local hyperthermia and/or small muscle mass exercise. ABSTRACT Heat and exercise therapies are recommended to improve vascular health across the lifespan. However, the haemodynamic effects of hyperthermia, exercise and their combination are inconsistent in young and elderly people. Here we investigated the acute effects of local-limb hyperthermia and exercise on limb haemodynamics in nine healthy, trained elderly (69 ± 5 years) and 10 young (26 ± 7 years) adults, hypothesising that the combination of local hyperthermia and exercise interact to increase leg perfusion, albeit to a lesser extent in the elderly. Participants underwent 90 min of single whole-leg heating, with the contralateral leg remaining as control, followed by 10 min of low-intensity incremental single-leg knee-extensor exercise with both the heated and control legs. Temperature profiles and leg haemodynamics at the femoral and popliteal arteries were measured. In both groups, heating increased whole-leg skin temperature and blood flow by 9.5 ± 1.2°C and 0.7 ± 0.2 L min-1 (>3-fold), respectively (P < 0.0001). Blood flow in the heated leg remained 0.7 ± 0.6 and 1.0 ± 0.8 L min-1 higher during exercise at 6 and 12 W, respectively (P < 0.0001). However, there were no differences in limb haemodynamics between cohorts, other than the elderly group exhibiting a 16 ± 6% larger arterial diameter and a 51 ± 6% lower blood velocity following heating (P < 0.0001). In conclusion, local hyperthermia-induced limb hyperperfusion and/or small muscle mass exercise hyperaemia are preserved in trained older people despite evident age-related structural and functional alterations in their leg conduit arteries.
Collapse
Affiliation(s)
- Nuno Koch Esteves
- Division of Sport, Health, and Exercise Sciences, Department of Life SciencesBrunel University LondonUxbridgeUK
| | | | - José González‐Alonso
- Division of Sport, Health, and Exercise Sciences, Department of Life SciencesBrunel University LondonUxbridgeUK
| |
Collapse
|
4
|
Wang H, Cheng L, Han Y. Effect of oral administration of GABA on thermoregulation in athletes during exercise in cold environments: A preliminary study. Front Nutr 2022; 9:883571. [PMID: 35911099 PMCID: PMC9335056 DOI: 10.3389/fnut.2022.883571] [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: 02/25/2022] [Accepted: 06/27/2022] [Indexed: 11/21/2022] Open
Abstract
Background γ-aminobutyric acid (GABA), a common ingredient in sports supplements and other health products, regulates body temperature in the preoptic area and anterior hypothalamus (PO/AH). To date, no study has examined the effect of GABA on thermoregulation during exercise in humans in a cold temperature environment (11 ± 0.3°C, 45% ± 2% relative humidity). Methods We performed a randomized, double-blind study. Ten trained male athletes consumed either a drink (3 ml/kg weight) containing GABA (1,000 mg, trial G) or an equivalent amount of placebo drink (trial C) before exercise. They rested for 20 min and then cycled at 60% of maximum output power for 40 min, pedaling at 60 rpm, and recovered for 20 min. Core temperature (Tc), skin temperature (upper arm, chest, thigh, calf), and heart rate (HR) were monitored at rest (T0), exercise begins (T20), 20 min of exercise (T40), the exercise ends (T60), and at recovery (T80). Results Compared to T0, Tc decreased significantly at T20 and increased significantly at T40, T60 and T80 (p < 0.01). From 35–80 min, the Tc was higher in trial G (peaked at 37.96 ± 0.25°C) than in trial C (37.89 ± 0.37°C), but it failed to reach significant difference (p > 0.05); Tsk continued to increase during exercise and was significantly higher than T0 at T40 (p < 0.05), T60 and T80 (p < 0.01). There was no significant difference in Tsk between the two trials (p > 0.05). Conclusion Our findings provide initial evidence that oral administration of GABA does not affect thermoregulation and has no adverse effects on the body as an ergogenic exercise supplement during exercise in cold environments.
Collapse
|
5
|
Nyberg M, Jones AM. Matching of O2 Utilization and O2 Delivery in Contracting Skeletal Muscle in Health, Aging, and Heart Failure. Front Physiol 2022; 13:898395. [PMID: 35774284 PMCID: PMC9237395 DOI: 10.3389/fphys.2022.898395] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/05/2022] [Indexed: 12/12/2022] Open
Abstract
Skeletal muscle is one of the most dynamic metabolic organs as evidenced by increases in metabolic rate of >150-fold from rest to maximal contractile activity. Because of limited intracellular stores of ATP, activation of metabolic pathways is required to maintain the necessary rates of ATP re-synthesis during sustained contractions. During the very early phase, phosphocreatine hydrolysis and anaerobic glycolysis prevails but as activity extends beyond ∼1 min, oxidative phosphorylation becomes the major ATP-generating pathway. Oxidative metabolism of macronutrients is highly dependent on the cardiovascular system to deliver O2 to the contracting muscle fibres, which is ensured through a tight coupling between skeletal muscle O2 utilization and O2 delivery. However, to what extent O2 delivery is ideal in terms of enabling optimal metabolic and contractile function is context-dependent and determined by a complex interaction of several regulatory systems. The first part of the review focuses on local and systemic mechanisms involved in the regulation of O2 delivery and how integration of these influences the matching of skeletal muscle O2 demand and O2 delivery. In the second part, alterations in cardiovascular function and structure associated with aging and heart failure, and how these impact metabolic and contractile function, will be addressed. Where applicable, the potential of exercise training to offset/reverse age- and disease-related cardiovascular declines will be highlighted in the context of skeletal muscle metabolic function. The review focuses on human data but also covers animal observations.
Collapse
Affiliation(s)
- Michael Nyberg
- Vascular Biology, Global Drug Discovery, Novo Nordisk A/S, Maaloev, Denmark
- *Correspondence: Michael Nyberg,
| | - Andrew M. Jones
- Department of Sport and Health Sciences, University of Exeter, Exeter, United Kingdom
| |
Collapse
|
6
|
Berton M, Bettonte S, Stader F, Battegay M, Marzolini C. Repository Describing the Anatomical, Physiological, and Biological Changes in an Obese Population to Inform Physiologically Based Pharmacokinetic Models. Clin Pharmacokinet 2022; 61:1251-1270. [PMID: 35699913 PMCID: PMC9439993 DOI: 10.1007/s40262-022-01132-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2022] [Indexed: 11/24/2022]
Abstract
Background Obesity is associated with physiological changes that can affect drug pharmacokinetics. Obese individuals are underrepresented in clinical trials, leading to a lack of evidence-based dosing recommendations for many drugs. Physiologically based pharmacokinetic (PBPK) modelling can overcome this limitation but necessitates a detailed description of the population characteristics under investigation. Objective The purpose of this study was to develop and verify a repository of the current anatomical, physiological, and biological data of obese individuals, including population variability, to inform a PBPK framework. Methods A systematic literature search was performed to collate anatomical, physiological, and biological parameters for obese individuals. Multiple regression analyses were used to derive mathematical equations describing the continuous effect of body mass index (BMI) within the range 18.5–60 kg/m2 on system parameters. Results In total, 209 studies were included in the database. The literature reported mostly BMI-related changes in organ weight, whereas data on blood flow and biological parameters (i.e. enzyme abundance) were sparse, and hence physiologically plausible assumptions were made when needed. The developed obese population was implemented in Matlab® and the predicted system parameters obtained from 1000 virtual individuals were in agreement with observed data from an independent validation obese population. Our analysis indicates that a threefold increase in BMI, from 20 to 60 kg/m2, leads to an increase in cardiac output (50%), liver weight (100%), kidney weight (60%), both the kidney and liver absolute blood flows (50%), and in total adipose blood flow (160%). Conclusion The developed repository provides an updated description of a population with a BMI from 18.5 to 60 kg/m2 using continuous physiological changes and their variability for each system parameter. It is a tool that can be implemented in PBPK models to simulate drug pharmacokinetics in obese individuals.
Collapse
Affiliation(s)
- Mattia Berton
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Sara Bettonte
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | | | - Manuel Battegay
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Catia Marzolini
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| |
Collapse
|
7
|
Richey RE, Hemingway HW, Moore AM, Olivencia-Yurvati AH, Romero SA. Acute heat exposure improves microvascular function in skeletal muscle of aged adults. Am J Physiol Heart Circ Physiol 2022; 322:H386-H393. [PMID: 35060753 PMCID: PMC8858667 DOI: 10.1152/ajpheart.00645.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acute heat exposure improves microvascular function in aged adults as assessed using reactive hyperemia. The cutaneous and skeletal muscle microcirculations are thought to contribute to this response, but this has never been confirmed due to the methodological challenges associated with differentiating blood flow between these vascular beds. We hypothesized that acute hot water immersion would improve endothelial-dependent, but not endothelial-independent vasodilation in the microcirculation of the vastus lateralis muscle in healthy aged adults. Participants (70 ± 5 yr) were immersed for 60 min in thermoneutral (36°C) or hot (40°C) water. Ninety minutes following immersion, skeletal muscle microdialysis was used to bypass the cutaneous circulation and directly assess endothelial-dependent and endothelial-independent vasodilation by measuring the local hyperemic response to graded infusions of acetylcholine (ACh, 27.5 and 55.0 mM) and sodium nitroprusside (SNP, 21 and 42 mM), respectively. The hyperemic response to 27.5 mM ACh did not differ between thermal conditions (P = 0.9). However, the hyperemic response to 55.0 mM ACh was increased with prior hot water immersion (thermoneutral immersion, 43.9 ± 23.2 mL/min/100 g vs. hot water immersion, 66.5 ± 25.5 mL/min/100 g; P < 0.01). Similarly, the hyperemic response to 21 mM SNP did not differ between thermal conditions (P = 0.3) but was increased following hot water immersion with the infusion of 42 mM SNP (thermoneutral immersion, 48.8 ± 25.6 mL/min/100 g vs. hot water immersion, 90.7 ± 53.5 mL/min/100 g; P < 0.01). These data suggest that acute heat exposure improves microvascular function in skeletal muscle of aged humans.NEW & NOTEWORTHY Acute heat exposure improves microvascular function in aged adults as assessed using reactive hyperemia. The cutaneous and skeletal muscle microcirculations are thought to contribute to this response, but this has never been confirmed due to the methodological challenges associated with differentiating blood flow between these vascular beds. Using the microdialysis technique to bypass the cutaneous circulation, we demonstrated that heat exposure improves endothelial-dependent and endothelial-independent vasodilation in the microcirculation of skeletal muscle in aged humans.
Collapse
Affiliation(s)
- Rauchelle E. Richey
- 1Department of Physiology and Anatomy, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas
| | - Holden W. Hemingway
- 1Department of Physiology and Anatomy, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M. Moore
- 1Department of Physiology and Anatomy, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H. Olivencia-Yurvati
- 1Department of Physiology and Anatomy, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas,2Department of Surgery, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A. Romero
- 1Department of Physiology and Anatomy, Human Vascular Physiology Laboratory, University of North Texas Health Science Center, Fort Worth, Texas
| |
Collapse
|
8
|
Amin SB, Mugele H, Dobler FE, Marume K, Moore JP, Lawley JS. Intra-rater reliability of leg blood flow during dynamic exercise using Doppler ultrasound. Physiol Rep 2021; 9:e15051. [PMID: 34617675 PMCID: PMC8496156 DOI: 10.14814/phy2.15051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 11/24/2022] Open
Abstract
Developing an exercise model that resembles a traditional form of aerobic exercise and facilitates a complete simultaneous assessment of multiple parameters within the oxygen cascade is critically for understanding exercise intolerances in diseased populations. Measurement of muscle blood flow is a crucial component of such a model and previous studies have used invasive procedures to determine blood flow kinetics; however, this may not be appropriate in certain populations. Furthermore, current models utilizing Doppler ultrasound use isolated limb exercise and while these studies have provided useful data, the exercise model does not mimic the whole-body physiological response to continuous dynamic exercise. Therefore, we aimed to measure common femoral artery blood flow using Doppler ultrasound during continuous dynamic stepping exercise performed at three independent workloads to assess the within day and between-day reliability for such an exercise modality. We report a within-session coefficient of variation of 5.8% from three combined workloads and a between-day coefficient of variation of 12.7%. These values demonstrate acceptable measurement accuracy and support our intention of utilizing this noninvasive exercise model for an integrative assessment of the whole-body physiological response to exercise in a range of populations.
Collapse
Affiliation(s)
- Sachin B. Amin
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | - Hendrik Mugele
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | - Florian E. Dobler
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| | | | | | - Justin S. Lawley
- Department Sport ScienceDivision of Performance Physiology and PreventionUniversity InnsbruckInnsbruckAustria
| |
Collapse
|
9
|
DeLorey DS. Sympathetic vasoconstriction in skeletal muscle: Modulatory effects of aging, exercise training, and sex. Appl Physiol Nutr Metab 2021; 46:1437-1447. [PMID: 34348066 DOI: 10.1139/apnm-2021-0399] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The sympathetic nervous system (SNS) is a critically important regulator of the cardiovascular system. The SNS controls cardiac output and its distribution, as well as peripheral vascular resistance and blood pressure at rest and during exercise. Aging is associated with increased blood pressure and decreased skeletal muscle blood flow at rest and in response to exercise. The mechanisms responsible for the blunted skeletal muscle blood flow response to dynamic exercise with aging have not been fully elucidated; however, increased muscle sympathetic nerve activity (MSNA), elevated vascular resistance and a decline in endothelium-dependent vasodilation are commonly reported in older adults. In contrast to aging, exercise training has been shown to reduce blood pressure and enhance skeletal muscle vascular function. Exercise training has been shown to enhance nitric oxide-dependent vascular function and may improve the vasodilatory capacity of the skeletal muscle vasculature; however, surprisingly little is known about the effect of exercise training on the neural control of circulation. The control of blood pressure and skeletal muscle blood flow also differs between males and females. Blood pressure and MSNA appear to be lower in young females compared to males. However, females experience a larger increase in MSNA with aging compared to males. The mechanism(s) for the altered SNS control of vascular function in females remain to be determined. Novelty: • This review will summarize our current understanding of the effects of aging, exercise training and sex on sympathetic vasoconstriction at rest and during exercise. • Areas where additional research is needed are also identified.
Collapse
Affiliation(s)
- Darren S DeLorey
- University of Alberta, Faculty of Kinesiology, Sport, and Recreation, Edmonton, Alberta, Canada;
| |
Collapse
|
10
|
Gliemann L, Rytter N, Yujia L, Tamariz-Ellemann A, Carter H, Hellsten Y. A High Activity Level Is Required for Augmented Muscle Capillarization in Older Women. Med Sci Sports Exerc 2021; 53:894-903. [PMID: 33844669 DOI: 10.1249/mss.0000000000002566] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study aimed to evaluate the influence of lifelong regular physical activity on skeletal muscle capillarization in women. METHODS Postmenopausal women, 61±4 yr old, were divided according to self-reported physical activity level over the past 20 yrs: sedentary (SED; n = 14), moderately active (MOD; n = 12), and very active (VERY; n = 15). Leg blood flow (LBF) was determined by ultrasound Doppler, and blood samples were drawn from the femoral artery and vein for calculation of leg oxygen uptake (LVO2) at rest and during one-legged knee extensor exercise. A skeletal muscle biopsy was obtained from the vastus lateralis and analyzed for capillarization and vascular endothelial growth factor (VEGF) and mitochondrial OXPHOS proteins. Platelets were isolated from venous blood and analyzed for VEGF content and effect on endothelial cell proliferation. RESULTS The exercise-induced rise in LBF and LVO2 was faster (P = 0.008) in VERY compared with SED and MOD. Steady-state LBF and LVO2 were lower (P < 0.04) in MOD and VERY compared with SED. Capillary-fiber ratio and capillary density were greater (P < 0.03) in VERY (1.65 ± 0.48 and 409.3 ± 57.5) compared with MOD (1.30 ± 0.19 and 365.0 ± 40.2) and SED (1.30 ± 0.30 and 356.2 ± 66.3). Skeletal muscle VEGF and OXPHOS complexes I, II, and V were ~1.6-fold and ~1.25-fold (P < 0.01) higher, respectively, in VERY compared with SED. Platelets from all groups induced an approximately nine-fold (P < 0.001) increase in endothelial cell proliferation. CONCLUSION A very active lifestyle is associated with superior skeletal muscle exercise hemodynamics and greater potential for oxygen extraction concurrent with a higher skeletal muscle capillarization and mitochondrial capacity.
Collapse
Affiliation(s)
- Lasse Gliemann
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | - Nicolai Rytter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | | | | | - Howard Carter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, DENMARK
| |
Collapse
|
11
|
Hanson BE, Joyner MJ, Casey DP. Sex-related differences in rapid-onset vasodilation: impact of aging. J Appl Physiol (1985) 2021; 130:206-214. [PMID: 33119464 DOI: 10.1152/japplphysiol.00663.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Rapid-onset vasodilation (ROV) in response to a single muscle contraction is attenuated with aging. Moreover, sex-related differences in muscle blood flow and vasodilation during dynamic exercise have been observed in young and older adults. The purpose of the present study was to explore if sex-related differences in ROV exist in young (n = 36, 25 ± 1 yr) and older (n = 32, 66 ± 1 yr) adults. Subjects performed single forearm contractions at 10%, 20%, and 40% maximal voluntary contraction. Brachial artery blood velocity and diameter were measured with Doppler ultrasound, and forearm vascular conductance (mL·min-1·100 mmHg-1) was calculated from blood flow (mL·min-1) and mean arterial pressure (mmHg) and used as a measure of ROV. Peak ROV was attenuated in women across all relative intensities in the younger and older groups (P < 0.05). In a subset of subjects with similar absolute workloads (∼5 kg and ∼11 kg), age-related differences in ROV were observed among both women and men (P < 0.05). However, only older women demonstrated an attenuated peak ROV compared with men (91 ± 6 vs. 121 ± 11 mL·min-1·100 mmHg-1, P < 0.05), a difference not observed in the young group (134 ± 8 vs. 154 ± 11 mL·min-1·100 mmHg-1, P = 0.15). Additionally, examining the slope of peak ROV across contraction intensities indicated a blunted response in older women compared with their younger counterparts (P < 0.05), with no differences observed between older and young men (P = 0.38). Our data suggest that sex-related differences in the rapid vasodilatory response to single muscle contractions exist in older but not young adults, such that older women have a blunted response compared with older men.NEW & NOTEWORTHY While rapid-onset vasodilation (ROV) has been shown to decrease in older individuals, it is unclear if sex contributes to the decline with aging. We sought to identify if sex-related differences exist in the ROV response to single forearm contractions in young and older adults. Our data suggest sex-related differences are present among older but not young individuals, with women having an attenuated response. These data indicate sex plays a role in decreased vasodilation with aging.
Collapse
Affiliation(s)
- Brady E Hanson
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Michael J Joyner
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Darren P Casey
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Abboud Cardiovascular Research Center, University of Iowa, Iowa City, Iowa.,Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa
| |
Collapse
|
12
|
Skattebo Ø, Calbet JAL, Rud B, Capelli C, Hallén J. Contribution of oxygen extraction fraction to maximal oxygen uptake in healthy young men. Acta Physiol (Oxf) 2020; 230:e13486. [PMID: 32365270 PMCID: PMC7540168 DOI: 10.1111/apha.13486] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 12/16/2022]
Abstract
We analysed the importance of systemic and peripheral arteriovenous O2 difference (
a-v¯O2 difference and a‐vfO2 difference, respectively) and O2 extraction fraction for maximal oxygen uptake (
V˙O2max). Fick law of diffusion and the Piiper and Scheid model were applied to investigate whether diffusion versus perfusion limitations vary with
V˙O2max. Articles (n = 17) publishing individual data (n = 154) on
V˙O2max, maximal cardiac output (
Q˙max; indicator‐dilution or the Fick method),
a-v¯O2 difference (catheters or the Fick equation) and systemic O2 extraction fraction were identified. For the peripheral responses, group‐mean data (articles: n = 27; subjects: n = 234) on leg blood flow (LBF; thermodilution), a‐vfO2 difference and O2 extraction fraction (arterial and femoral venous catheters) were obtained.
Q˙max and two‐LBF increased linearly by 4.9‐6.0 L · min–1 per 1 L · min–1 increase in
V˙O2max (R2 = .73 and R2 = .67, respectively; both P < .001). The
a-v¯O2 difference increased from 118‐168 mL · L–1 from a
V˙O2max of 2‐4.5 L · min–1 followed by a reduction (second‐order polynomial: R2 = .27). After accounting for a hypoxemia‐induced decrease in arterial O2 content with increasing
V˙O2max (R2 = .17; P < .001), systemic O2 extraction fraction increased up to ~90% (
V˙O2max: 4.5 L · min–1) with no further change (exponential decay model: R2 = .42). Likewise, leg O2 extraction fraction increased with
V˙O2max to approach a maximal value of ~90‐95% (R2 = .83). Muscle O2 diffusing capacity and the equilibration index Y increased linearly with
V˙O2max (R2 = .77 and R2 = .31, respectively; both P < .01), reflecting decreasing O2 diffusional limitations and accentuating O2 delivery limitations. In conclusion, although O2 delivery is the main limiting factor to
V˙O2max, enhanced O2 extraction fraction (≥90%) contributes to the remarkably high
V˙O2max in endurance‐trained individuals.
Collapse
Affiliation(s)
- Øyvind Skattebo
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Jose A. L. Calbet
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
- Department of Physical Education and Research Institute of Biomedical and Health Sciences (IUIBS) University of Las Palmas de Gran Canaria Gran Canaria Spain
| | - Bjarne Rud
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Carlo Capelli
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
- Department of Neurosciences, Biomedicine and Movement Sciences University of Verona Verona Italy
| | - Jostein Hallén
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| |
Collapse
|
13
|
Stader F, Siccardi M, Battegay M, Kinvig H, Penny MA, Marzolini C. Repository Describing an Aging Population to Inform Physiologically Based Pharmacokinetic Models Considering Anatomical, Physiological, and Biological Age-Dependent Changes. Clin Pharmacokinet 2020; 58:483-501. [PMID: 30128967 DOI: 10.1007/s40262-018-0709-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Aging is characterized by anatomical, physiological, and biological changes that can impact drug kinetics. The elderly are often excluded from clinical trials and knowledge about drug kinetics and drug-drug interaction magnitudes is sparse. Physiologically based pharmacokinetic modeling can overcome this clinical limitation but detailed descriptions of the population characteristics are essential to adequately inform models. OBJECTIVE The objective of this study was to develop and verify a population database for aging Caucasians considering anatomical, physiological, and biological system parameters required to inform a physiologically based pharmacokinetic model that included population variability. METHODS A structured literature search was performed to analyze age-dependent changes of system parameters. All collated data were carefully analyzed, and descriptive mathematical equations were derived. RESULTS A total of 362 studies were found of which 318 studies were included in the analysis as they reported rich data for anthropometric parameters and specific organs (e.g., liver). Continuous functions could be derived for most system parameters describing a Caucasian population from 20 to 99 years of age with variability. Areas with sparse data were identified such as tissue composition, but knowledge gaps were filled with plausible qualified assumptions. The developed population was implemented in Matlab® and estimated system parameters from 1000 virtual individuals were in accordance with independent observed data showing the robustness of the developed population. CONCLUSIONS The developed repository for aging subjects provides a singular specific source for key system parameters needed for physiologically based pharmacokinetic modeling and can in turn be used to investigate drug kinetics and drug-drug interaction magnitudes in the elderly.
Collapse
Affiliation(s)
- Felix Stader
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland. .,Infectious Disease Modelling Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Marco Siccardi
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Manuel Battegay
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Hannah Kinvig
- Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Melissa A Penny
- Infectious Disease Modelling Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Catia Marzolini
- Division of Infectious Diseases and Hospital Epidemiology, Departments of Medicine and Clinical Research, University Hospital Basel, Basel, Switzerland.,University of Basel, Basel, Switzerland
| |
Collapse
|
14
|
Junejo RT, Ray CJ, Marshall JM. Prostaglandin contribution to postexercise hyperemia is dependent on tissue oxygenation during rhythmic and isometric contractions. Physiol Rep 2020; 8:e14471. [PMID: 32562377 PMCID: PMC7305242 DOI: 10.14814/phy2.14471] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/27/2020] [Accepted: 05/10/2020] [Indexed: 12/21/2022] Open
Abstract
The role of prostaglandins (PGs) in exercise hyperemia is controversial. We tested their contributions in moderate intensity forearm exercise, whether their release is oxygen (O2)‐dependent or affected by aging. A total of 12 young (21 ± 1 years) and 11 older (66 ± 2 years) recreationally active men performed rhythmic and isometric handgrip contractions at 60% maximum voluntary contraction for 3 min during air breathing after placebo, after cyclooxygenase (COX) inhibition with aspirin, while breathing 40% O2 and during their combination (aspirin + 40% O2). Forearm blood flow (FBF) was recorded with venous occlusion plethysmography (forearm vascular conductance (FVC): FBF/mean arterial pressure). Venous efflux of PGI2 and PGE2 were assessed by immunoassay. Postcontraction increases in FVC were similar for rhythmic and isometric contractions in young and older men, and accompanied by similar increases in efflux of PGI2 and PGE2. Aspirin attenuated the efflux of PGI2 by 75%–85%, PGE2 by 50%–70%, (p < .05 within group; p > .05 young versus. older), and postcontraction increases in FVC by 22%–27% and 17%–21% in young and older men, respectively (p < .05 within group and young versus. older). In both age groups, 40% O2 and aspirin + 40% O2 caused similar inhibition of the increases in FVC and efflux of PGs as aspirin alone (p < .05 within group). These results indicate that PGs make substantial contributions to the postcontraction hyperemia of rhythmic and isometric contractions at moderate intensities in recreationally active young and older men. Given PGI2 is mainly released by endothelium and PGE2 by muscle fibers, we propose PG generation is dependent on the contraction‐induced falls in O2 at these sites.
Collapse
Affiliation(s)
- Rehan T Junejo
- School of Sport, Exercise & Rehabilitation Sciences, College of Life & Environmental Sciences, Birmingham, UK
| | - Clare J Ray
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Janice M Marshall
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
15
|
Preobrazenski N, Islam H, Drouin PJ, Bonafiglia JT, Tschakovsky ME, Gurd BJ. A novel gravity-induced blood flow restriction model augments ACC phosphorylation and PGC-1α mRNA in human skeletal muscle following aerobic exercise: a randomized crossover study. Appl Physiol Nutr Metab 2019; 45:641-649. [PMID: 31778310 DOI: 10.1139/apnm-2019-0641] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
This study tested the hypothesis that a novel, gravity-induced blood flow restricted (BFR) aerobic exercise (AE) model will result in greater activation of the AMPK-PGC-1α pathway compared with work rate-matched non-BFR. Thirteen healthy males (age: 22.4 ± 3.0 years; peak oxygen uptake: 42.4 ± 7.3 mL/(kg·min)) completed two 30-min work rate-matched bouts of cycling performed with their legs below (CTL) and above their heart (BFR) at ∼2 weeks apart. Muscle biopsies were taken before, immediately, and 3 h after exercise. Blood was drawn before and immediately after exercise. Our novel gravity-induced BFR model led to less muscle oxygenation during BFR compared with CTL (O2Hb: p = 0.01; HHb: p < 0.01) and no difference in muscle activation (p = 0.53). Plasma epinephrine increased following both BFR and CTL (p < 0.01); however, only norepinephrine increased more following BFR (p < 0.01). PGC-1α messenger RNA (mRNA) increased more following BFR (∼6-fold) compared with CTL (∼4-fold; p = 0.036). VEGFA mRNA increased (p < 0.01) similarly following BFR and CTL (p = 0.21), and HIF-1α mRNA did not increase following either condition (p = 0.21). Phosphorylated acetyl-coenzyme A carboxylase (ACC) increased more following BFR (p < 0.035) whereas p-PKA substrates, p-p38 MAPK, and acetyl-p53 increased (p < 0.05) similarly following both conditions (p > 0.05). In conclusion, gravity-induced BFR is a viable BFR model that demonstrated an important role of AMPK signalling on augmenting PGC-1α mRNA. Novelty Gravity-induced BFR AE reduced muscle oxygenation without impacting muscle activation, advancing gravity-induced BFR as a simple, inexpensive BFR model. Gravity-induced BFR increased PGC-1α mRNA and ACC phosphorylation more than work rate-matched non-BFR AE. This is the first BFR AE study to concurrently measure blood catecholamines, muscle activation, and muscle oxygenation.
Collapse
Affiliation(s)
- Nicholas Preobrazenski
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| | - Hashim Islam
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| | - Patrick J Drouin
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| | - Jacob T Bonafiglia
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| | - Michael E Tschakovsky
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| | - Brendon J Gurd
- School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada.,School of Kinesiology and Health Studies, Queen's University, 28 Division Street, Kingston, ON K7L 3N6, Canada
| |
Collapse
|
16
|
Hureau TJ, Weavil JC, Thurston TS, Wan HY, Gifford JR, Jessop JE, Buys MJ, Richardson RS, Amann M. Pharmacological attenuation of group III/IV muscle afferents improves endurance performance when oxygen delivery to locomotor muscles is preserved. J Appl Physiol (1985) 2019; 127:1257-1266. [PMID: 31513446 DOI: 10.1152/japplphysiol.00490.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We sought to investigate the role of group III/IV muscle afferents in limiting endurance exercise performance, independently of their role in optimizing locomotor muscle O2 delivery. While breathing 100% O2 to ensure a similar arterial O2 content ([Formula: see text]) in both trials, eight male cyclists performed 5-km time trials under control conditions (HCTRL) and with lumbar intrathecal fentanyl (HFENT) impairing neural feedback from the lower limbs. After each time trial, common femoral artery blood flow (FBF) was quantified (Doppler ultrasound) during constant-load cycling performed at the average power of the preceding time trial. The assessment of end-tidal gases, hemoglobin content and saturation, and FBF facilitated the calculation of leg O2 delivery. Locomotor muscle activation during cycling was estimated from vastus lateralis EMG. With electrical femoral nerve stimulation, peripheral and central fatigue were quantified by pre- to postexercise decreases in quadriceps twitch torque (ΔQtw) and voluntary activation (ΔVA), respectively. FBF (~16 mL·min-1·W-1; P = 0.6), [Formula: see text] (~24 mL O2/dL; P = 0.9), and leg O2 delivery (~0.38 mL O2·min-1·W-1; P = 0.9) were not different during HCTRL and HFENT. Mean power output and time to completion were significantly improved by 9% (~310 W vs. ~288 W) and 3% (~479 s vs. ~463 s), respectively, during HFENT compared with HCTRL. Quadriceps muscle activation was 9 ± 7% higher during HFENT compared with HCTRL (P < 0.05). ΔQtw was significantly greater in HFENT compared with HCTRL (54 ± 8% vs. 39 ± 9%), whereas ΔVA was not different (~5%; P = 0.3) in both trials. These findings reveal that group III/IV muscle afferent feedback limits whole body endurance exercise performance and peripheral fatigue by restricting neural activation of locomotor muscle.NEW & NOTEWORTHY Group III/IV muscle afferent feedback facilitates endurance performance by optimizing locomotor muscle O2 delivery but also limits performance by restricting neural drive to locomotor muscle. To isolate the performance-limiting effect of these sensory neurons, we pharmacologically attenuated their central projection during a cycling time trial while controlling for locomotor muscle O2 delivery. With no difference in leg O2 delivery, afferent blockade attenuated the centrally mediated restriction in motoneuronal output and improved cycling performance.
Collapse
Affiliation(s)
- Thomas J Hureau
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Medicine and EA 3072: Mitochondria, Oxidative Stress and Muscular Protection Laboratory, University of Strasbourg, Strasbourg, France
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Jayson R Gifford
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jacob E Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Michael J Buys
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| | - Russell S Richardson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah.,Department of Anesthesiology, University of Utah, Salt Lake City, Utah
| |
Collapse
|
17
|
Gliemann L, Vestergaard Hansen C, Rytter N, Hellsten Y. Regulation of skeletal muscle blood flow during exercise. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
18
|
Hamasaki A, Arima S, Hirakoba K. Changes in pulmonary oxygen uptake and muscle deoxygenation kinetics during cycling exercise in older women performing walking training for 12 weeks. Eur J Appl Physiol 2018; 118:2179-2188. [PMID: 30046886 DOI: 10.1007/s00421-018-3946-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 07/17/2018] [Indexed: 11/25/2022]
Abstract
PURPOSE This study examined the hypothesis that walking training (WT) could accelerate the slowed time constant (τ) of phase II in pulmonary oxygen uptake ([Formula: see text]O2) on-kinetics in older women. Also, we aimed to demonstrate that O2 delivery and O2 utilization were better matched at the site of gas exchange in exercising muscles when τ[Formula: see text]O2 was shortened. METHODS 20 recreationally active older women underwent WT sessions of approximately 60 min, 3-4 times a week for 12 weeks. We assessed [Formula: see text]O2, heart rate (HR) and deoxygenated-hemoglobin concentration ([HHb]) kinetics during a constant-load exercise test before training (0 week-Pre), and at 6 and 12 weeks (6 weeks-Mid, 12 weeks-Post) throughout the training period. RESULTS Maximal oxygen uptake ([Formula: see text]O2max) was unchanged throughout the training program. τHR tended to decline at Mid (58.6 ± 22.0 s), and was significantly shorter at Post (51.7 ± 21.7 s, p = 0.01) compared to Pre (67.1 ± 23.8 s). τ[Formula: see text]O2 significantly decreased from 38.9 ± 8.6 s for Pre, to 31.5 ± 7.9 s for Mid (p = 0.02), and 32.3 ± 10.5 s for Post (p = 0.03). The normalized [HHb] to [Formula: see text]O2 ratio (Δ[HHb]/Δ[Formula: see text]O2) at Pre (1.32 ± 0.93) gradually approached the perfectly matched value (= 1.0) at Mid (1.15 ± 0.61) and Post (1.07 ± 0.52). CONCLUSIONS The restoration to baseline (≒ 30 s) of the slower τ[Formula: see text]O2 due to WT, which may reflect better matching of O2 delivery and O2 utilization at the site of gas exchange, suggests that a longer period of WT could be a useful tool for improving exercise tolerance in older individuals.
Collapse
Affiliation(s)
- Akiko Hamasaki
- Katsuura Orthopaedics Clinic, 485-252 Tona, Katsuura, Chiba, 299-5225, Japan.
| | - Saburo Arima
- Katsuura Orthopaedics Clinic, 485-252 Tona, Katsuura, Chiba, 299-5225, Japan
| | - Kohji Hirakoba
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka, Japan
| |
Collapse
|
19
|
Weavil JC, Hureau TJ, Thurston TS, Sidhu SK, Garten RS, Nelson AD, McNeil CJ, Richardson RS, Amann M. Impact of age on the development of fatigue during large and small muscle mass exercise. Am J Physiol Regul Integr Comp Physiol 2018; 315:R741-R750. [PMID: 29995457 DOI: 10.1152/ajpregu.00156.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
To examine the impact of aging on neuromuscular fatigue following cycling (CYC; large active muscle mass) and single-leg knee-extension (KE; small active muscle mass) exercise, 8 young (25 ± 4 years) and older (72 ± 6 years) participants performed CYC and KE to task failure at a given relative intensity (80% of peak power output). The young also matched CYC and KE workload and duration of the old (iso-work comparison). Peripheral and central fatigue were quantified via pre-/postexercise decreases in quadriceps twitch torque (∆Qtw, electrical femoral nerve stimulation) and voluntary activation (∆VA). Although young performed 77% and 33% more work during CYC and KE, respectively, time to task failure in both modalities was similar to the old (~9.5 min; P > 0.2). The resulting ΔQtw was also similar between groups (CYC ~40%, KE ~55%; P > 0.3); however, ∆VA was, in both modalities, approximately double in the young (CYC ~6%, KE ~9%; P < 0.05). While causing substantial peripheral and central fatigue in both exercise modalities in the old, ∆Qtw in the iso-work comparison was not significant (CYC; P = 0.2), or ~50% lower (KE; P < 0.05) in the young, with no central fatigue in either modality ( P > 0.4). Based on iso-work comparisons, healthy aging impairs fatigue resistance during aerobic exercise. Furthermore, comparisons of fatigue following exercise at a given relative intensity mask the age-related difference observed following exercise performed at the same workload. Finally, although active muscle mass has little influence on the age-related difference in the rate of fatigue at a given relative intensity, it substantially impacts the comparison during exercise at a given absolute intensity.
Collapse
Affiliation(s)
- Joshua C Weavil
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center , Salt Lake City, Utah
| | - Thomas J Hureau
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Taylor S Thurston
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Simranjit K Sidhu
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Ryan S Garten
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center , Salt Lake City, Utah
| | - Ashley D Nelson
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah
| | - Chris J McNeil
- School of Health and Exercise Sciences, University of British Columbia , Kelowna , Canada
| | - Russell S Richardson
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center , Salt Lake City, Utah
| | - Markus Amann
- Department of Internal Medicine, University of Utah , Salt Lake City, Utah.,Geriatric Research, Education, and Clinical Center, Salt Lake City Veterans Affairs Medical Center , Salt Lake City, Utah.,Department of Anesthesiology, University of Utah , Salt Lake City, Utah
| |
Collapse
|
20
|
Reilly H, Lane LM, Egaña M. Lack of age-specific influence on leg blood flow during incremental calf plantar-flexion exercise in men and women. Eur J Appl Physiol 2018; 118:989-1001. [PMID: 29502172 DOI: 10.1007/s00421-018-3833-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 02/21/2018] [Indexed: 11/28/2022]
Abstract
PURPOSE Age-related exercising leg blood flow (LBF) responses during dynamic knee-extension exercise and forearm blood flow responses during handgrip exercise are preserved in normally active men but attenuated in activity-matched women. We explored whether these age- and sex-specific effects are also apparent during isometric calf plantar-flexion incremental exercise. METHODS Normally active young men (YM, n = 15, 24 ± 2 years), young women (YW, n = 8, 22 ± 1 years), older men (OM, n = 13, 70 ± 7 years) and older women (OW, n = 10, 64 ± 7 years) were tested. LBF was measured between contractions using venous occlusion plethysmography. RESULTS Peak force obtained was higher (P < 0.05) in men compared with women and in young compared with older individuals. However, peak LBF (YM; 971 ± 328 ml min-1, OM; 985 ± 504 ml min-1, YW; 844 ± 366 ml min-1, OW; 960 ± 244 ml min-1) and peak leg vascular conductance [LVC = LBF/(MAP + hydrostatic pressure)] responses (YM; 6.0 ± 1.8 ml min-1 mmHg-1, OM; 5.5 ± 2.8 ml min-1 mmHg-1, YW; 5.3 ± 2.1 ml min-1 mmHg-1, OW; 5.5 ± 1.6 ml min-1 mmHg-1) were similar among the four groups. Furthermore, the hyperaemic (YM; 8.8 ± 3.7 ml min-1 %Fpeak-1 OM; 8.3 ± 5.4 ml min-1 %Fpeak-1, YW; 8.2 ± 3.5 ml min-1 %Fpeak-1, OW; 9.6 ± 2.2 ml min-1 %Fpeak-1) and vasodilatory responses (YM; 0.053 ± 0.020 ml min-1 mmHg-1 %Fpeak-1, OM; 0.048 ± 0.028 ml min-1 mmHg-1 %Fpeak-1, YW; 0.051 ± 0.019 ml min-1 mmHg-1 %Fpeak-1, OW; 0.055 ± 0.014 ml min-1 mmHg-1 %Fpeak-1) were not different among the four groups. These results were accompanied by similar resting LBF responses among groups and were not affected when data were normalised to estimated leg muscle mass. CONCLUSIONS Our results demonstrate that exercising LBF responses during isometric incremental calf muscle exercise are preserved in older men and women, suggesting that the previously observed age-related attenuations in leg and forearm hyperaemia among women may be muscle-group specific.
Collapse
Affiliation(s)
- Heather Reilly
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Louise M Lane
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland
| | - Mikel Egaña
- Department of Physiology, School of Medicine, Trinity College Dublin, Dublin 2, Ireland.
| |
Collapse
|
21
|
Muller MD, Li Z, Sica CT, Luck JC, Gao Z, Blaha CA, Cauffman AE, Ross AJ, Winkler NJR, Herr MD, Brandt K, Wang J, Gallagher DC, Karunanayaka P, Vesek J, Leuenberger UA, Yang QX, Sinoway LI. Muscle oxygenation during dynamic plantar flexion exercise: combining BOLD MRI with traditional physiological measurements. Physiol Rep 2016; 4:4/20/e13004. [PMID: 27798357 PMCID: PMC5099966 DOI: 10.14814/phy2.13004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 09/26/2016] [Indexed: 11/24/2022] Open
Abstract
Blood-oxygen-level-dependent magnetic resonance imaging (BOLD MRI) has the potential to quantify skeletal muscle oxygenation with high temporal and high spatial resolution. The purpose of this study was to characterize skeletal muscle BOLD responses during steady-state plantar flexion exercise (i.e., during the brief rest periods between muscle contraction). We used three different imaging modalities (ultrasound of the popliteal artery, BOLD MRI, and near-infrared spectroscopy [NIRS]) and two different exercise intensities (2 and 6 kg). Six healthy men underwent three separate protocols of dynamic plantar flexion exercise on separate days and acute physiological responses were measured. Ultrasound studies showed the percent change in popliteal velocity from baseline to the end of exercise was 151 ± 24% during 2 kg and 589 ± 145% during 6 kg. MRI studies showed an abrupt decrease in BOLD signal intensity at the onset of 2 kg exercise, indicating deoxygenation. The BOLD signal was further reduced during 6 kg exercise (compared to 2 kg) at 1 min (-4.3 ± 0.7 vs. -1.2 ± 0.4%, P < 0.001). Similarly, the change in the NIRS muscle oxygen saturation in the medial gastrocnemius was -11 ± 4% at 2 kg and -38 ± 11% with 6 kg (P = 0.041). In conclusion, we demonstrate that BOLD signal intensity decreases during plantar flexion and this effect is augmented at higher exercise workloads.
Collapse
Affiliation(s)
- Matthew D Muller
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Zhijun Li
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Christopher T Sica
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - J Carter Luck
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Zhaohui Gao
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Cheryl A Blaha
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Aimee E Cauffman
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Amanda J Ross
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Nathan J R Winkler
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Michael D Herr
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Kristen Brandt
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jianli Wang
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - David C Gallagher
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Prasanna Karunanayaka
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jeffrey Vesek
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Urs A Leuenberger
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Qing X Yang
- Department of Radiology, Center for NMR Research, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Lawrence I Sinoway
- Penn State Hershey Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| |
Collapse
|
22
|
Roman MA, Rossiter HB, Casaburi R. Exercise, ageing and the lung. Eur Respir J 2016; 48:1471-1486. [PMID: 27799391 DOI: 10.1183/13993003.00347-2016] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 06/27/2016] [Indexed: 02/07/2023]
Abstract
This review provides a pulmonary-focused description of the age-associated changes in the integrative physiology of exercise, including how declining lung function plays a role in promoting multimorbidity in the elderly through limitation of physical function. We outline the ageing of physiological systems supporting endurance activity: 1) coupling of muscle metabolism to mechanical power output; 2) gas transport between muscle capillary and mitochondria; 3) matching of muscle blood flow to its requirement; 4) oxygen and carbon dioxide carrying capacity of the blood; 5) cardiac output; 6) pulmonary vascular function; 7) pulmonary oxygen transport; 8) control of ventilation; and 9) pulmonary mechanics and respiratory muscle function. Deterioration in function occurs in many of these systems in healthy ageing. Between the ages of 25 and 80 years pulmonary function and aerobic capacity each decline by ∼40%. While the predominant factor limiting exercise in the elderly likely resides within the function of the muscles of ambulation, muscle function is (at least partially) rescued by exercise training. The age-associated decline in pulmonary function, however, is not recovered by training. Thus, loss in pulmonary function may lead to ventilatory limitation in exercise in the active elderly, limiting the ability to accrue the health benefits of physical activity into senescence.
Collapse
Affiliation(s)
- Michael A Roman
- Division of Respiratory Medicine, Rockyview Hospital, University of Calgary, Calgary, AB, Canada
| | - Harry B Rossiter
- Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute, Torrance, CA, USA.,Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Richard Casaburi
- Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, Los Angeles Biomedical Research Institute, Torrance, CA, USA
| |
Collapse
|
23
|
Perkisas S, De Cock A, Verhoeven V, Vandewoude M. Physiological and architectural changes in the ageing muscle and their relation to strength and function in sarcopenia. Eur Geriatr Med 2016. [DOI: 10.1016/j.eurger.2015.12.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
24
|
Rodway GW, Lovelace AJ, Lanspa MJ, McIntosh SE, Bell J, Briggs B, Weaver LK, Yanowitz F, Grissom CK. Sildenafil and Exercise Capacity in the Elderly at Moderate Altitude. Wilderness Environ Med 2016; 27:307-15. [PMID: 27116921 DOI: 10.1016/j.wem.2016.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 12/15/2015] [Accepted: 01/20/2016] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Hypobaric hypoxia decreases exercise capacity and causes hypoxic pulmonary vasoconstriction and pulmonary hypertension. The phosphodiesterase-5 inhibitor sildenafil is a pulmonary vasodilator that may improve exercise capacity at altitude. We aimed to determine whether sildenafil improves exercise capacity, measured as maximal oxygen consumption (peak V̇o2), at moderate altitude in adults 60 years or older. METHODS The design was a randomized, double-blind, placebo-controlled, crossover study. After baseline cardiopulmonary exercise testing at 1400 m, 12 healthy participants (4 women) aged 60 years or older, who reside permanently at approximately 1400 m and are regularly active in self-propelled mountain recreation above 2000 m, performed maximal cardiopulmonary cycle exercise tests in a hypobaric chamber at a simulated altitude of 2750 m after ingesting sildenafil and after ingesting a placebo. RESULTS After placebo, mean peak V̇o2 was significantly lower at 2750 m than 1400 m: 37.0 mL · kg(-1) · min(-1) (95% CI, 32.7 to 41.3) vs 39.1 mL · kg(-1) · min(-1) (95% CI, 33.5 to 44.7; P = .020). After placebo, there was no difference in heart rate (HR) or maximal workload at either altitude (z = 0.182; P = .668, respectively). There was no difference between sildenafil and placebo at 2750 m in peak V̇o2 (P = .668), O2 pulse (P = .476), cardiac index (P = .143), stroke volume index (z = 0.108), HR (z = 0.919), or maximal workload (P = .773). Transthoracic echocardiography immediately after peak exercise at 2750 m showed tricuspid annular plane systolic velocity was significantly higher after sildenafil than after placebo (P = .019), but showed no difference in tricuspid annular plane systolic excursion (P = .720). CONCLUSIONS Sildenafil (50 mg) did not improve exercise capacity in adults 60 years or older at moderate altitude in our study. This might be explained by a "dosing effect" or insufficiently high altitude.
Collapse
Affiliation(s)
- George W Rodway
- University of Utah School of Nursing, Salt Lake City, UT (Dr Rodway).
| | - Anne J Lovelace
- Department of Pulmonary and Critical Care (Ms Lovelace, Drs Lanspa and Grissom, and Mr Briggs)
| | - Michael J Lanspa
- Department of Pulmonary and Critical Care (Ms Lovelace, Drs Lanspa and Grissom, and Mr Briggs)
| | | | - James Bell
- Intermountain Medical Center (Mr Bell and Dr Weaver), Murray, UT; Hyperbaric Medicine (Mr Bell), LDS Hospital, Salt Lake City, UT
| | - Ben Briggs
- Department of Pulmonary and Critical Care (Ms Lovelace, Drs Lanspa and Grissom, and Mr Briggs)
| | - Lindell K Weaver
- Intermountain Medical Center (Mr Bell and Dr Weaver), Murray, UT; Department of Pulmonary and Critical Care (Dr Weaver); School of Medicine (Drs Weaver and Yanowitz), University of Utah, Salt Lake City, UT
| | - Frank Yanowitz
- and ECG Services and Cardiac Rehabilitation (Dr Yanowitz); School of Medicine (Drs Weaver and Yanowitz), University of Utah, Salt Lake City, UT
| | - Colin K Grissom
- Department of Pulmonary and Critical Care (Ms Lovelace, Drs Lanspa and Grissom, and Mr Briggs)
| |
Collapse
|
25
|
Hearon CM, Dinenno FA. Regulation of skeletal muscle blood flow during exercise in ageing humans. J Physiol 2015; 594:2261-73. [PMID: 26332887 DOI: 10.1113/jp270593] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/13/2015] [Indexed: 12/12/2022] Open
Abstract
The regulation of skeletal muscle blood flow and oxygen delivery to contracting skeletal muscle is complex and involves the mechanical effects of muscle contraction; local metabolic, red blood cell and endothelium-derived substances; and the sympathetic nervous system (SNS). With advancing age in humans, skeletal muscle blood flow is typically reduced during dynamic exercise and this is due to a lower vascular conductance, which could ultimately contribute to age-associated reductions in aerobic exercise capacity, a primary predictor of mortality in both healthy and diseased ageing populations. Recent findings have highlighted the contribution of endothelium-derived substances to blood flow control in contracting muscle of older adults. With advancing age, impaired nitric oxide availability due to scavenging by reactive oxygen species, in conjunction with elevated vasoconstrictor signalling via endothelin-1, reduces the local vasodilatory response to muscle contraction. Additionally, ageing impairs the ability of contracting skeletal muscle to blunt sympathetic vasoconstriction (i.e. 'functional sympatholysis'), which is critical for the proper regulation of tissue blood flow distribution and oxygen delivery, and could further reduce skeletal muscle perfusion during high intensity and/or large muscle mass exercise in older adults. We propose that initiation of endothelium-dependent hyperpolarization is the underlying signalling event necessary to properly modulate sympathetic vasoconstriction in contracting muscle, and that age-associated impairments in red blood cell adenosine triphosphate release and stimulation of endothelium-dependent vasodilatation may explain impairments in both local vasodilatation and functional sympatholysis with advancing age in humans.
Collapse
Affiliation(s)
- Christopher M Hearon
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA
| | - Frank A Dinenno
- Human Cardiovascular Physiology Laboratory, Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, 80523, USA.,Center for Cardiovascular Research, Colorado State University, Fort Collins, CO, 80523, USA
| |
Collapse
|
26
|
Nyberg M, Piil P, Egelund J, Sprague RS, Mortensen SP, Hellsten Y. Potentiation of cGMP signaling increases oxygen delivery and oxidative metabolism in contracting skeletal muscle of older but not young humans. Physiol Rep 2015; 3:3/8/e12508. [PMID: 26272735 PMCID: PMC4562591 DOI: 10.14814/phy2.12508] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with progressive loss of cardiovascular and skeletal muscle function. The impairment in physical capacity with advancing age could be related to an insufficient peripheral O2 delivery to the exercising muscles. Furthermore, the mechanisms underlying an impaired blood flow regulation remain unresolved. Cyclic guanosine monophosphate (cGMP) is one of the main second messengers that mediate smooth muscle vasodilation and alterations in cGMP signaling could, therefore, be one mechanism by which skeletal muscle perfusion is impaired with advancing age. The current study aimed to evaluate the effect of inhibiting the main enzyme involved in cGMP degradation, phosphodiesterase 5 (PDE5), on blood flow and O2 delivery in contracting skeletal muscle of young and older humans. A group of young (23 ± 1 years) and a group of older (72 ± 2 years) male human subjects performed submaximal knee-extensor exercise in a control setting and following intake of the highly selective PDE5 inhibitor sildenafil. Sildenafil increased leg O2 delivery (6-9%) and leg O2 uptake (10-12%) at all three exercise intensities in older but not young subjects. The increase in leg O2 delivery with sildenafil in the older subjects correlated with the increase in leg O2 uptake (r (2) = 0.843). These findings suggest an insufficient O2 delivery to the contracting skeletal muscle of aged individuals and that reduced cGMP availability is a novel mechanism underlying impaired skeletal muscle perfusion with advancing age.
Collapse
Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Peter Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jon Egelund
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Randy S Sprague
- Department of Pharmacological and Physiological Science, Saint Louis, Missouri, USA
| | - Stefan P Mortensen
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
27
|
Nyberg M, Hellsten Y. Reduced blood flow to contracting skeletal muscle in ageing humans: is it all an effect of sand through the hourglass? J Physiol 2015; 594:2297-305. [PMID: 26095873 DOI: 10.1113/jp270594] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 06/05/2015] [Indexed: 01/27/2023] Open
Abstract
The ability to sustain a given absolute submaximal workload declines with advancing age, likely to be due to a lower level of blood flow and O2 delivery to the exercising muscles. Given that physical inactivity mimics many of the physiological changes associated with ageing, separating the physiological consequences of ageing and physical inactivity can be challenging; yet, observations from cross-sectional and longitudinal studies on the effects of physical activity have provided some insight. Physical activity has the potential to offset the age-related decline in blood flow to contracting skeletal muscle during exercise where systemic blood flow is not limited by cardiac output, thereby improving O2 delivery and allowing for an enhanced energy production from oxidative metabolism. The mechanisms underlying the increase in blood flow with regular physical activity include improved endothelial function and the ability for functional sympatholysis - an attenuation of the vasoconstrictor effect of sympathetic nervous activity. These vascular adaptations with physical activity are likely to be an effect of improved nitric oxide and ATP signalling. Collectively, precise matching of blood flow and O2 delivery to meet the O2 demand of the active skeletal muscle of aged individuals during conditions where systemic blood flow is not limited by cardiac output seems to a large extent to be related to the level of physical activity.
Collapse
Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| |
Collapse
|
28
|
Calf exercise-induced vasodilation is blunted in healthy older adults with increased walking performance fatigue. Exp Gerontol 2014; 57:1-5. [DOI: 10.1016/j.exger.2014.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 04/17/2014] [Accepted: 04/22/2014] [Indexed: 11/21/2022]
|
29
|
Sellami M, Abderrahman AB, Casazza GA, Kebsi W, Lemoine-Morel S, Bouguerra L, Zouhal H. Effect of age and combined sprint and strength training on plasma catecholamine responses to a Wingate-test. Eur J Appl Physiol 2014; 114:969-82. [PMID: 24500570 DOI: 10.1007/s00421-014-2828-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 01/20/2014] [Indexed: 11/30/2022]
Abstract
PURPOSE The purpose of this research is to study the effects of aging and combined training (sprint and strength) on catecholamine responses [adrenaline (A) and noradrenaline (NA)]. METHODS Thirty-two male subjects voluntarily participated in this study. They were randomly divided into four groups: A young trained group (age 21.4 ± 1.2 years, YT, n = 8), a young control group (age 21.9 ± 1.9 years, YC, n = 8), a middle-aged trained group (age 40.8 ± 2.8 years, AT, n = 8) and a middle-aged control group (age 40.4 ± 2.0 years, AC, n = 8). YT and AT participated in a high intensity sprint and strength training program (HISST) for 13 weeks. All the participants realized the Wingate-test before (P1) and after (P2) HISST. Plasma A and NA concentrations were determined at rest (A 0, NA0) and at the end of exercise (A max, NAmax). RESULTS At P1, a significant difference (p < 0.05) in terms of age was observed for NA0 and A 0 between YT and AT and between control groups YC and AC. This age effect disappeared after training when compared YT and AT. After HISST, A max increased significantly (p < 0.05) in YT and AT (from 3.08 ± 0.17 to 3.23 ± 0.34 nmol l(-1) in YT and from 3.23 ± 0.52 to 4.59 ± 0.10 nmol l(-1) in AT). However, NAmax increased significantly (p < 0.05) in AT only (from 3.34 ± 0.31 to 3.75 ± 0.60 nmol l(-1)). A max was highly increased in AT compared to YT (4.59 ± 0.10 vs. 3.23 ± 0.34 nmol l(-1)), respectively. CONCLUSION The combined training (sprint and strength) appeared to reduce the age effect of the catecholamine response both at rest and in response to exercise.
Collapse
Affiliation(s)
- Maha Sellami
- Movement, Sport, Health and Sciences laboratory (M2S). UFR-APS, University of Rennes 2/ENS-Rennes, Avenue Charles Tillon, CS 24414, 35044, Rennes Cedex, France
| | | | | | | | | | | | | |
Collapse
|
30
|
Rudroff T, Weissman JA, Bucci M, Seppänen M, Kaskinoro K, Heinonen I, Kalliokoski KK. Positron emission tomography detects greater blood flow and less blood flow heterogeneity in the exercising skeletal muscles of old compared with young men during fatiguing contractions. J Physiol 2013; 592:337-49. [PMID: 24247981 DOI: 10.1113/jphysiol.2013.264614] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The purpose of this study was to investigate blood flow and its heterogeneity within and among the knee muscles in five young (26 ± 6 years) and five old (77 ± 6 years) healthy men with similar levels of physical activity while they performed two types of submaximal fatiguing isometric contraction that required either force or position control. Positron emission tomography (PET) and [(15)O]-H2O were used to determine blood flow at 2 min (beginning) and 12 min (end) after the start of the tasks. Young and old men had similar maximal forces and endurance times for the fatiguing tasks. Although muscle volumes were lower in the older subjects, total muscle blood flow was similar in both groups (young men: 25.8 ± 12.6 ml min(-1); old men: 25.1 ± 15.4 ml min(-1); age main effect, P = 0.77) as blood flow per unit mass of muscle in the exercising knee extensors was greater in the older (12.5 ± 6.2 ml min(-1) (100 g)(-1)) than the younger (8.6 ± 3.6 ml min(-1) (100 g)(-1)) men (age main effect, P = 0.001). Further, blood flow heterogeneity in the exercising knee extensors was significantly lower in the older (56 ± 27%) than the younger (67 ± 34%) men. Together, these data show that although skeletal muscles are smaller in older subjects, based on the intact neural drive to the muscle and the greater, less heterogeneous blood flow per gram of muscle, old fit muscle achieves adequate exercise hyperaemia.
Collapse
Affiliation(s)
- Thorsten Rudroff
- Department of Health and Exercise Science, Colorado State University, 220 Moby B Complex, Fort Collins, CO 80523-1582, USA.
| | | | | | | | | | | | | |
Collapse
|
31
|
Laughlin MH, Davis MJ, Secher NH, van Lieshout JJ, Arce-Esquivel AA, Simmons GH, Bender SB, Padilla J, Bache RJ, Merkus D, Duncker DJ. Peripheral circulation. Compr Physiol 2013; 2:321-447. [PMID: 23728977 DOI: 10.1002/cphy.c100048] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Blood flow (BF) increases with increasing exercise intensity in skeletal, respiratory, and cardiac muscle. In humans during maximal exercise intensities, 85% to 90% of total cardiac output is distributed to skeletal and cardiac muscle. During exercise BF increases modestly and heterogeneously to brain and decreases in gastrointestinal, reproductive, and renal tissues and shows little to no change in skin. If the duration of exercise is sufficient to increase body/core temperature, skin BF is also increased in humans. Because blood pressure changes little during exercise, changes in distribution of BF with incremental exercise result from changes in vascular conductance. These changes in distribution of BF throughout the body contribute to decreases in mixed venous oxygen content, serve to supply adequate oxygen to the active skeletal muscles, and support metabolism of other tissues while maintaining homeostasis. This review discusses the response of the peripheral circulation of humans to acute and chronic dynamic exercise and mechanisms responsible for these responses. This is accomplished in the context of leading the reader on a tour through the peripheral circulation during dynamic exercise. During this tour, we consider what is known about how each vascular bed controls BF during exercise and how these control mechanisms are modified by chronic physical activity/exercise training. The tour ends by comparing responses of the systemic circulation to those of the pulmonary circulation relative to the effects of exercise on the regional distribution of BF and mechanisms responsible for control of resistance/conductance in the systemic and pulmonary circulations.
Collapse
Affiliation(s)
- M Harold Laughlin
- Department of Medical Pharmacology and Physiology, and the Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Layec G, Haseler LJ, Richardson RS. Reduced muscle oxidative capacity is independent of O2 availability in elderly people. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1183-1192. [PMID: 22760857 PMCID: PMC3705121 DOI: 10.1007/s11357-012-9442-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 05/29/2012] [Indexed: 06/01/2023]
Abstract
Impaired O2 transport to skeletal muscle potentially contributes to the decline in aerobic capacity with aging. Thus, we examined whether (1) skeletal muscle oxidative capacity decreases with age and (2) O2 availability or mitochondrial capacity limits the maximal rate of mitochondrial ATP synthesis in vivo in sedentary elderly individuals. We used (31)P-magnetic resonance spectroscopy ((31)P-MRS) to examine the PCr recovery kinetics in six young (26 ± 10 years) and six older (69 ± 3 years) sedentary subjects following 4 min of dynamic plantar flexion exercise under different fractions of inspired O2 (FiO2, normoxia 0.2; hyperoxia 1.0). End-exercise pH was not significantly different between old (7.04 ± 0.10) and young (7.05 ± 0.04) and was not affected by breathing hyperoxia (old 7.08 ± 0.08, P > 0.05 and young 7.05 ± 0.03). Likewise, end-exercise PCr was not significantly different between old (19 ± 4 mM) and young (24 ± 5 mM) and was not changed in hyperoxia. The PCr recovery time constant was significantly longer in the old (36 ± 9 s) compared to the young in normoxia (23 ± 8 s, P < 0.05) and was not significantly altered by breathing hyperoxia in both the old (35 ± 9 s) and young (29 ± 10 s) groups. Therefore, this study reveals that the muscle oxidative capacity of both sedentary young and old individuals is independent of O2 availability and that the decline in oxidative capacity with age is most likely due to limited mitochondrial content and/or mitochondrial dysfunction and not O2 availability.
Collapse
Affiliation(s)
- Gwenael Layec
- Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA.
| | | | | |
Collapse
|
33
|
Gravelle BMR, Murias JM, Spencer MD, Paterson DH, Kowalchuk JM. Adjustments of pulmonary O2 uptake and muscle deoxygenation during ramp incremental exercise and constant-load moderate-intensity exercise in young and older adults. J Appl Physiol (1985) 2012; 113:1466-75. [PMID: 22961268 DOI: 10.1152/japplphysiol.00884.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The matching of muscle O(2) delivery to O(2) utilization can be inferred from the adjustments in muscle deoxygenation (Δ[HHb]) and pulmonary O(2) uptake (Vo(2p)). This study examined the adjustments of Vo(2p) and Δ[HHb] during ramp incremental (RI) and constant-load (CL) exercise in adult males. Ten young adults (YA; age: 25 ± 5 yr) and nine older adults (OA; age: 70 ± 3 yr) completed two RI tests and six CL step transitions to a work rate (WR) corresponding to 1) 80% of the estimated lactate threshold (same relative WR) and 2) 50 W (same absolute WR). Vo(2p) was measured breath by breath, and Δ[HHb] of the vastus lateralis was measured using near-infrared spectroscopy. Δ[HHb]-WR profiles were normalized from baseline (0%) to peak Δ[HHb] (100%) and fit using a sigmoid function. The sigmoid slope (d) was greater (P < 0.05) in OA (0.027 ± 0.01%/W) compared with YA (0.017 ± 0.01%/W), and the c/d value (a value corresponding to 50% of the amplitude) was smaller (P < 0.05) for OA (133 ± 40 W) than for YA (195 ± 51 W). No age-related differences in the sigmoid parameters were reported when WR was expressed as a percentage of peak WR. Vo(2p) kinetics compared with Δ[HHb] kinetics for the 50-W transition were similar between YA and OA; however, Δ[HHb] kinetics during the transition to 80% of the lactate threshold were faster than Vo(2p) kinetics in both groups. The greater reliance on O(2) extraction displayed in OA during RI exercise suggests a lower O(2) delivery-to-O(2) utilization relationship at a given absolute WR compared with YA.
Collapse
Affiliation(s)
- Braden M R Gravelle
- Canadian Centre for Activity and Aging, The University of Western Ontario, London, Ontario, Canada
| | | | | | | | | |
Collapse
|
34
|
Zerbini L, Brighenti A, Pellegrini B, Bortolan L, Antonetti T, Schena F. Effects of acute hypoxia on the oxygen uptake kinetics of older adults during cycling exercise. Appl Physiol Nutr Metab 2012; 37:744-52. [DOI: 10.1139/h2012-048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulmonary oxygen uptake, heart rate (HR), and deoxyhemoglobin (HHb) kinetics were studied in a group of older adults exercising in hypoxic conditions. Fourteen healthy older adults (aged 66 ± 6 years) performed 4 exercise sessions that consisted of (i) an incremental test to exhaustion on a cycloergometer while breathing normoxic room air (fractional inspired oxygen (FiO2) = 20.9% O2); (ii) an incremental test to exhaustion on a cycloergometer while breathing hypoxic room air (FiO2 = 15% O2); (iii) 3 repeated square wave cycling exercises at moderate intensity while breathing normoxic room air; and (iv) 3 repeated square wave cycling exercises at moderate intensity while breathing hypoxic room air. During all exercise sessions, pulmonary gas exchange was measured breath-by-breath; HHb was determined on the vastus lateralis muscle by near-infrared spectroscopy; and HR was collected beat-by-beat. The pulomary oxygen uptake kinetics became slower in hypoxia (31 ± 9 s) than in normoxia (27 ± 7 s) because of an increased mismatching between O2 delivery to O2 utilization at the level of the muscle. The HR and HHb kinetics did not change between hypoxia and normoxia,
Collapse
Affiliation(s)
- Livio Zerbini
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| | - Alfredo Brighenti
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| | - Barbara Pellegrini
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| | - Lorenzo Bortolan
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| | - Tommaso Antonetti
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| | - Federico Schena
- CeRiSM, Centre of Sport Health and Mountain Via Matteo del Ben, 5/b, University of Verona, 38068 Rovereto, Italy
- Faculty of Exercise and Sport Science, University of Verona, Italy
| |
Collapse
|
35
|
Moore DJ, Gonzales JU, Tucker SH, Elavsky S, Proctor DN. Exercise-induced vasodilation is associated with menopause stage in healthy middle-aged women. Appl Physiol Nutr Metab 2012; 37:418-24. [PMID: 22486379 DOI: 10.1139/h2012-015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leg exercise hemodynamics during single-leg knee extensions were compared among healthy groups of early perimenopausal (n = 15), late perimenopausal (n = 12), and early postmenopausal (n = 11) women. Femoral blood flow (FBF) and vascular conductance (FVC) at rest and during very light work rates (0 and 5 W) were similar among all three menopause stage groups. Vascular responses at 10 W (FBF) and 20 W (FBF and FVC) were significantly higher (P < 0.05) in early perimenopausal compared with late perimenopausal women. At 15 and 25 W, FBF and FVC were similar between late perimenopausal and early postmenopausal groups but higher (P < 0.05) in early perimenopausal women as compared with the other two menopausal groups. In the combined sample of all three menopause stage groups, follicle-stimulating hormone was significantly correlated with vascular conductance during submaximal (15 W) exercise (R = -0.56, P < 0.001), even after adjustment for age, fitness, LDL cholesterol, and abdominal fat (R = -0.46, P = 0.005). Collectively, these findings suggest that in middle-aged women, there is an association between menopause stage and leg vascular responsiveness during exercise.
Collapse
Affiliation(s)
- David J Moore
- Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA
| | | | | | | | | |
Collapse
|
36
|
Heterogeneous vascular responses to hypoxic forearm exercise in young and older adults. Eur J Appl Physiol 2011; 112:3087-95. [PMID: 22198326 DOI: 10.1007/s00421-011-2280-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 12/05/2011] [Indexed: 10/14/2022]
Abstract
We aimed to assess age-related differences in compensatory hypoxic vasodilation during moderate-to-high dynamic exercise at absolute workloads. We hypothesized healthy older adults (n = 12, 61 ± 1 years) would exhibit impaired hypoxic vasodilation at a moderate absolute workload, and this effect would be exaggerated at a higher workload when compared to young adults (n = 17, 27 ± 2 years). Forearm blood flow (FBF) was measured with Doppler ultrasound. Dynamic forearm exercise (20 contractions/min) was completed at two absolute workloads (8 and 12 kg) under normoxic (0.21 FiO2, ~98% SpO2) and isocapnic hypoxic (~0.10 FiO2, 80% SpO2) conditions performed in random order. FBF was normalized as forearm vascular conductance (FBF / mean arterial blood pressure = FVC) to control for differences in blood pressure and to assess vasodilation. FVC increased with exercise and hypoxia (main effects, p < 0.05); vascular responses were not different between young and older adults (interaction effect exercise × group p = 0.37 and hypoxia × group p = 0.96). Results were confirmed when analyzed as either an absolute or relative change in FVC (ΔFVC and %ΔFVC, respectively). Although group responses to hypoxia were not different, individual results were highly variable (i.e., some adults constricted and others dilated to hypoxia). These data suggest (1) compensatory hypoxic vasodilation in older adults is not impaired during forearm exercise at both moderate and higher absolute exercise intensities, and (2) vascular responses to hypoxia are heterogeneous in both young and older adults. Results suggest unique individual differences exist in factors regulating vascular responses to hypoxia.
Collapse
|
37
|
Brochu P, Brodeur J, Krishnan K. Derivation of cardiac output and alveolar ventilation rate based on energy expenditure measurements in healthy males and females. J Appl Toxicol 2011; 32:564-80. [DOI: 10.1002/jat.1651] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 12/03/2010] [Accepted: 12/03/2010] [Indexed: 11/09/2022]
Affiliation(s)
- Pierre Brochu
- Ministère du Développement durable, de l'Environnement et des Parcs, Direction du suivi et de l'état de l'environnement, Service des avis et expertises scientifiques, gouvernement du Québec, édifice Marie-Guyart; 7; e; étage, 675, boulevard René-Lévesque Est; Québec; QC; G1R 5V7; Canada
| | - Jules Brodeur
- Département de santé environnementale et santé au travail, Faculté de médecine; Université de Montréal; C.P. 6128, succursale Centre-Ville; Montréal; QC; H3C 3J7; Canada
| | - Kannan Krishnan
- Département de santé environnementale et santé au travail, Faculté de médecine; Université de Montréal; C.P. 6128, succursale Centre-Ville; Montréal; QC; H3C 3J7; Canada
| |
Collapse
|
38
|
Parker B, Capizzi J, Augeri A, Grimaldi A, Proctor D, Thompson P. Sex-specific effect of aging on submaximal leg exercise hemodynamics in middle-aged and older adults. Eur J Appl Physiol 2010; 111:1369-79. [PMID: 21153657 DOI: 10.1007/s00421-010-1766-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2010] [Indexed: 10/18/2022]
Abstract
The purpose of the study was to examine predictors of the leg hemodynamic response to exercise in middle- and older-aged men and women. Femoral artery blood flow (FBF), mean arterial pressure (MAP), and femoral vascular conductance (FVC, calculated as the quotient of FBF and MAP) were measured at rest and during 5 min of single knee-extensor exercise at ~10 W workload in healthy men (n = 31) and women (n = 32) (age 40-72 years). Age, menopausal status, maximal quadriceps strength, blood lipids, vitamin D levels, maximal oxygen uptake (VO(2max)), physical activity, blood pressure, estimated quadriceps muscle mass, and body mass index (BMI) were also assessed. The effect of age on FBF and FVC was negative and significant in men (r = -0.44 and -0.42 and p = 0.01 and 0.02, respectively) but was abolished by normalization to estimated quadriceps muscle (p = 0.18 and 0.73, respectively). There was no effect of age on leg hemodynamic responses to exercise in women (alone or normalized to quadriceps muscle), but menopausal status was a significant predictor of FVC and normalized FVC (p = 0.04 and 0.02, respectively). The multivariate model for exercising FVC in men (in order of strongest to weakest predictors) included quadriceps strength, BMI, resting FVC, age, and high-density lipoprotein cholesterol. The multivariate model for exercising FVC in women included quadriceps mass, systolic blood pressure, vitamin D, age, VO(2max), waist circumference, and physical activity score. These findings suggest that factors besides chronological age mediate exercising leg hemodynamics in middle-aged to older adults and that these factors are sex-specific.
Collapse
Affiliation(s)
- Beth Parker
- Henry Low Heart Center, Department of Cardiology, Hartford Hospital, Hartford, CT 06102, USA.
| | | | | | | | | | | |
Collapse
|
39
|
McDaniel J, Hayman MA, Ives S, Fjeldstad AS, Trinity JD, Wray DW, Richardson RS. Attenuated exercise induced hyperaemia with age: mechanistic insight from passive limb movement. J Physiol 2010; 588:4507-17. [PMID: 20876201 DOI: 10.1113/jphysiol.2010.198770] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The influence of age on the central and peripheral contributors to exercise-induced hyperaemia is unclear. Utilizing a reductionist approach, we compared the peripheral and central haemodynamic responses to passive limb movement (exercise without an increase in metabolism) in 11 old (71 ± 9 years of age S.D.) and 11 young (24 ± 2 years of age) healthy subjects. Cardiac output (CO), heart rate (HR), stroke volume (SV), mean arterial pressure (MAP), and femoral blood flow of the passively moved and control legs were evaluated second-by-second during 2 min of passive knee extension at a rate of 1 Hz. Compared to the young, the old group exhibited a significantly attenuated increase in HR (7 ± 4% vs. 13 ± 7% S.D.), CO (10 ± 6% vs. 18 ± 8%) and femoral blood flow in the passively moved (123 ± 55% vs. 194 ± 57%) and control legs (47 ± 43% vs. 77 ± 96%). In addition, the change in vascular conductance in the passively moving limb was also significantly attenuated in the old (2.4 ± 1.2 ml min(-1) mmHg(-1)) compared to the young (4.3 ± 1.7 ml min(-1) mmHg(-1)). In both groups all main central and peripheral changes that occurred at the onset of passive knee extension were transient, lasting only 45 s. In a paradigm where metabolism does not play a role, these data reveal that both central and peripheral haemodynamic mechanisms are likely to be responsible for the 30% reduction in exercise-induced hyperaemia with age.
Collapse
Affiliation(s)
- John McDaniel
- George E. Whalen VA Medical Center, Salt Lake City, Utah 84148, USA.
| | | | | | | | | | | | | |
Collapse
|
40
|
Speeding of VO2 kinetics in response to endurance-training in older and young women. Eur J Appl Physiol 2010; 111:235-43. [DOI: 10.1007/s00421-010-1649-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2010] [Indexed: 11/25/2022]
|
41
|
DeLorey DS, Buckwalter JB, Mittelstadt SW, Anton MM, Kluess HA, Clifford PS. Is tonic sympathetic vasoconstriction increased in the skeletal muscle vasculature of aged canines? Am J Physiol Regul Integr Comp Physiol 2010; 299:R1342-9. [PMID: 20702803 DOI: 10.1152/ajpregu.00194.2010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that tonic adrenergic and nonadrenergic receptor-mediated sympathetic vasoconstriction would increase at rest and during exercise with advancing age. Young (n = 6; 22 ± 1 mo; means ± SE) and old (n = 6; 118 ± 9 mo) beagles were studied. Selective antagonists for alpha-1, alpha-2, neuropeptide Y (NPY), and purinergic (P(2x)) receptors were infused at rest and during treadmill running at 2.5 mph and 4 mph with 2.5% grade. Prazosin produced similar increases in vascular conductance in young and old beagles at rest (Young: 158 ± 34%; Old: 98 ± 19%) and during exercise at 2.5 mph (Young: 80 ± 10%; Old: 58 ± 12%) and 4 mph and 2.5% grade (Young: 57 ± 5%; Old: 26 ± 4%). Rauwolscine caused similar (P > 0.05) increases in vascular conductance in old compared with young dogs at rest (Young: 119 ± 25%; Old: 64 ± 22%) and at 2.5 mph (Young: 86 ± 13%; Old: 60 ± 7%) and 4 mph with 2.5% grade (Young: 61 ± 5%; Old: 43 ± 7%). N2-(diphenylacetyl)-N-[4-hydroxyphenyl)methyl]-d-arginine amide (BIBP) caused a smaller increase (P < 0.05) in vascular conductance in old compared with young dogs at rest (Young: 179 ± 44%; Old: 91 ± 22%), whereas similar increases (P > 0.05) of experimental limb vascular conductance in young and old dogs occurred following BIBP during exercise at 2.5 mph (Young: 56 ± 16%; Old: 50 ± 12%) and 4 mph and 2.5% grade (Young: 45 ± 10%; Old: 25 ± 7%). Pyridoxal-phosphate-6-azophenyl-2'-4'-disulfonic acid infusion produced a larger increase in vascular conductance in old compared with young beagles at rest (Young: 88 ± 14%; Old: 191 ± 58%), whereas similar increases were observed at 2.5 mph (Young: 47 ± 18%; Old: 31 ± 11%) and 4 mph with 2.5% grade (Young: 26 ± 13%; Old: -18 ± 8%). At rest, NPY receptor-mediated restraint of skeletal muscle blood flow was reduced with advancing age, whereas P(2x) receptor-mediated restraint of skeletal muscle blood flow was increased. During exercise, the magnitude of adrenergic and nonadrenergic sympathetic vasoconstriction was not different between young and old dogs. Overall, these data demonstrate that adrenergic receptor-mediated vasoconstriction was not elevated at rest, but nonadrenergic sympathetic vasoconstriction was altered under basal conditions in aged beagles.
Collapse
Affiliation(s)
- D S DeLorey
- Faculty of Physical Education and Recreation, Univ. of Alberta, P-320-P Van Vliet Centre, Edmonton, Alberta T6G 2H9 Canada.
| | | | | | | | | | | |
Collapse
|
42
|
Differences in exercise limb blood flow and muscle deoxygenation with age: contributions to O2 uptake kinetics. Eur J Appl Physiol 2010; 110:739-51. [DOI: 10.1007/s00421-010-1546-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2010] [Indexed: 10/19/2022]
|
43
|
Jackson DN, Moore AW, Segal SS. Blunting of rapid onset vasodilatation and blood flow restriction in arterioles of exercising skeletal muscle with ageing in male mice. J Physiol 2010; 588:2269-82. [PMID: 20375140 DOI: 10.1113/jphysiol.2010.189811] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Exercise capacity and skeletal muscle blood flow are diminished with ageing but little is known of underlying changes in microvascular haemodynamics. Further, it is not clear how the sympathetic nervous system affects the microcirculation of skeletal muscle with ageing or whether sex differences prevail in the regulation of arteriolar diameter in response to muscle contractions. In the gluteus maximus muscle of C57BL/6 mice, we tested the hypothesis that ageing would impair 'rapid onset vasodilatation' (ROV) in distributing arterioles (second-order, 2A) of old (20-month) males (OM) and females (OF) relative to young (3-month) males (YM) and females (YF). Neither resting (approximately 17 microm) nor maximum (approximately 30 microm) 2A diameters differed between groups. In response to single tetanic contractions at 100 Hz (duration, 100-1000 ms), ROV responses were blunted by half in OM relative to OF, YM or YF. With no effect in YM, blockade of alpha-adrenoreceptors with phentolamine (1 mum) restored ROV in OM. Topical noradrenaline (1 nM) blunted ROV in YM and YF to levels seen in OM and further suppressed ROV in OM (P < 0.05). To evaluate arteriolar blood flow, red blood cell velocity was measured in 2A of OM and YM; respective heart rates (353 +/- 22 vs. 378 +/- 15 beats min(1)) and carotid arterial blood pressures (76 +/- 3 vs. 76 +/- 1 mmHg) were not different. Blood flows at rest (0.6 +/- 0.1 vs. 1.6 +/- 0.2 nl s(1)) and during maximum dilatation (2.0 +/- 0.8 vs. 5.4 +/- 0.8 nl s(1)) with sodium nitroprusside (10 microM) were attenuated >60% (P < 0.05) in OM. Blood flow at peak ROV was blunted by 75-80% in OM vs. YM (P < 0.05). In response to 30 s of rhythmic contractions at 2, 4 and 8 Hz, progressive dilatations did not differ with age or sex. Nevertheless, resting and peak blood flows in YM were 2- to 3-fold greater (P < 0.05) than OM. We suggest that ageing blunts ROV and restricts blood flow to skeletal muscle of OM through subtle activation of alpha-adrenoreceptors in microvascular resistance networks.
Collapse
|
44
|
Simultaneous Dynamic Blood Oxygen Level-Dependent Magnetic Resonance Imaging of Foot and Calf Muscles. Invest Radiol 2009; 44:741-7. [DOI: 10.1097/rli.0b013e3181b248f9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
45
|
INVERSE THERMODILUTION WITH CONVENTIONAL PULMONARY ARTERY CATHETERS FOR THE ASSESSMENT OF CEREBRAL, HEPATIC, RENAL, AND FEMORAL BLOOD FLOW. Shock 2009; 32:194-200. [DOI: 10.1097/shk.0b013e318194c73a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
46
|
Hogan TS. Exercise-induced reduction in systemic vascular resistance: a covert killer and an unrecognised resuscitation challenge? Med Hypotheses 2009; 73:479-84. [PMID: 19631477 DOI: 10.1016/j.mehy.2009.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2009] [Revised: 06/06/2009] [Accepted: 06/11/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Systemic vascular resistance falls in exercise as a consequence of metabolically-linked vasodilatation in active skeletal muscles. This exercise-induced vasodilatation is closely linked with reduced muscle tissue oxygen tension in and is characterised by reduced response to adrenergic vasoconstrictor mechanisms which is often referred to as functional sympatholysis. Systemic arterial blood pressure in exercise is maintained at normal or, more commonly, at elevated levels by increase in cardiac output and increased sympathetic vasomotor tone. Recovery of normal resting skeletal muscle tissue oxygen tension and skeletal muscle vascular tone after exercise depends on the post-exercise recovery process. This process requires ongoing elevated skeletal muscle perfusion and can therefore be predicted to be impaired in shock and cardiopulmonary resuscitation scenarios. Comprehensive consideration of this exercise physiology and its extrapolation into shock, cardiac arrest and resuscitation scenarios supports the proposal that exercise-induced sympatholytic vasodilatation in skeletal muscle may be of considerable unrecognised significance for resuscitation medicine. MAIN HYPOTHESIS: Reduced systemic vascular resistance due to pre-existing exercise-induced sympatholytic vasodilatation in skeletal muscle can significantly exacerbate systemic arterial hypotension in acute shock states and resuscitation scenarios. SUB-HYPOTHESES: 1. Onset of syncope, clinical shock states and pulseless electrical activity can occur at significantly higher cardiac output levels in subjects who were engaged in immediate pre-morbid exercise as compared to resting subjects. 2. The efficacy of external chest compression in generating coronary and cerebral perfusion in cardiopulmonary resuscitation can be significantly impaired when cardiac arrest has occurred during exercise. 3. The efficacy of adrenergic vasopressor agents in resuscitation scenarios can be significantly impaired in subjects who were engaged in immediate pre-morbid exercise. CURRENT EVIDENCE The limited available evidence is compatible with the hypothesis being true but does not provide direct confirmation. There is no evidence available directly supporting or refuting the hypothesis. IMPLICATIONS Significant potential clinical implications are outlined relating to the management of cardiopulmonary and trauma resuscitation for patients who were involved in immediate pre-morbid exercise, particularly, but not exclusively, at higher exercise intensities. There are also significant potential prognostic implications. CONCLUSION Reduction in systemic vascular resistance due to exercise-induced sympatholytic vasodilatation in skeletal muscle may largely explain the reported poor success rate for cardiopulmonary resuscitation with prompt defibrillation for sudden cardiac arrest in young previously healthy athletes. Investigation of this unexplored area of pathophysiology poses major difficulties but could lead to significant improvements in the outcomes of resuscitation for patients who were involved in immediate pre-morbid exercise.
Collapse
Affiliation(s)
- Tom S Hogan
- Department of Anaesthesia, Connolly Hospital, Dublin 15, Ireland.
| |
Collapse
|
47
|
Krix M, Weber MA, Kauczor HU, Delorme S, Krakowski-Roosen H. Changes in the micro-circulation of skeletal muscle due to varied isometric exercise assessed by contrast-enhanced ultrasound. Eur J Radiol 2009; 76:110-6. [PMID: 19541442 DOI: 10.1016/j.ejrad.2009.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 04/17/2009] [Accepted: 05/06/2009] [Indexed: 10/20/2022]
Abstract
PURPOSE To quantitatively assess local muscle micro-circulation with real-time contrast-enhanced ultrasound (CEUS) during different exercises and compare the results with performed muscle work and global blood flow. MATERIALS AND METHODS Sixteen low mechanical index CEUS examinations of the right lower leg flexors of healthy volunteers were performed using a continuous infusion of SonoVue(®) (4.8 mL/300 s). Several muscle perfusion parameters were extracted from derived CEUS signal intensity time curves during different isometric exercises (10-50% of maximum individual strength for 20-30s) and then correlated with the performed muscle work or force, and the whole lower leg blood flow which we measured simultaneously by venous occlusion plethysmography (VOP). RESULTS The shapes of the CEUS curve during and after exercise differed individually depending on the performed muscle work. The maximum blood volume MAX was observed only after exercise cessation and was significantly correlated with the performed muscle force (r=0.77, p<0.0001). The blood volume over exercise time was inversely correlated with the spent muscle work (r=-0.60, p=0.006). CEUS and VOP measurements correlated only at rest and after the exercise. During exercise, mean CEUS local blood volume decreased (from 3.48 to 2.19 (∼mL)), while mean VOP global blood flow increased (mean, from 3.96 to 7.71 mL/100 mg/min). CONCLUSION Real-time low-MI CEUS provides complementary information about the local muscle micro-circulation compared to established blood flow measures. CEUS may be used for a better understanding of muscle perfusion physiology and in the diagnosis of micro-circulation alterations such as in peripheral arterial occlusive disease or diabetic angiopathy.
Collapse
Affiliation(s)
- Martin Krix
- German Cancer Research Center, Research Program Imaging and Radiooncology, Department of Radiology, Heidelberg, Germany.
| | | | | | | | | |
Collapse
|
48
|
Copp SW, Ferreira LF, Herspring KF, Musch TI, Poole DC. The effects of aging on capillary hemodynamics in contracting rat spinotrapezius muscle. Microvasc Res 2009; 77:113-9. [DOI: 10.1016/j.mvr.2008.11.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 11/12/2008] [Accepted: 11/13/2008] [Indexed: 10/21/2022]
|
49
|
Betik AC, Hepple RT. Determinants of VO2 max decline with aging: an integrated perspective. Appl Physiol Nutr Metab 2008; 33:130-40. [PMID: 18347663 DOI: 10.1139/h07-174] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aging is associated with a progressive decline in the capacity for physical activity. Central to this decline is a reduction in the maximal rate of oxygen utilization, or VO2 max. This critical perspective examines the roles played by the factors that determine the rate of muscle oxygen delivery versus those that determine the utilization of oxygen by muscle as a means of probing the reasons for VO2 max decline with aging. Reductions in muscle oxygen delivery, principally due to reduced cardiac output and perhaps also a maldistribution of cardiac output, appear to play the dominant role up until late middle age. On the other hand, there is a decline in skeletal muscle oxidative capacity with aging, due in part to mitochondrial dysfunction, which appears to play a particularly important role in extreme old age (senescence) where skeletal muscle VO2 max is observed to decline by approximately 50% even under conditions of similar oxygen delivery as young adult muscle. It is noteworthy that at least the structural aspects of the capillary bed do not appear to be reduced in a manner that would compromise the capacity for muscle oxygen diffusion even in senescence.
Collapse
Affiliation(s)
- Andrew C Betik
- Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4
| | | |
Collapse
|
50
|
Carlson RE, Kirby BS, Voyles WF, Dinenno FA. Evidence for impaired skeletal muscle contraction-induced rapid vasodilation in aging humans. Am J Physiol Heart Circ Physiol 2008; 294:H1963-70. [DOI: 10.1152/ajpheart.01084.2007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We tested the hypothesis that aging is associated with an impaired contraction-induced rapid vasodilation in healthy adults. We reasoned that employing single contractions of a small muscle mass would allow us to isolate the local rapid vasodilatory responses independent of systemic hemodynamic and sympathetic neural influences on forearm hemodynamics. We measured forearm blood flow (Doppler ultrasound) and arterial blood pressure (Finapres) on a beat-by-beat basis and calculated the changes in forearm vascular conductance (ΔFVC) in response to forearm contractions in 18 young (24 ± 1 yr) and 13 older (62 ± 2 yr) healthy subjects. Single, 1-s dynamic forearm contractions were performed with the experimental arm slightly above heart level at 5, 10, 20, and 40% of the subjects' maximal voluntary contraction (MVC) in random order. In general, muscle contractions evoked a rapid increase in FVC that reached a peak within approximately four to five cardiac cycles postcontraction in both age groups. At 5% MVC, there were no significant age-related differences in contraction-induced forearm vasodilation. However, the peak vasodilatory responses were impaired ∼40–45% in older adults at 10, 20, and 40% MVC, as were the total vasodilatory responses (area under curve ∼40–50%; all P < 0.05). Additionally, the immediate vasodilation (first cardiac cycle postcontraction) for the 20% and 40% MVC trials was also impaired ∼50% with age ( P < 0.05). There were no significant age-group differences in MVC or forearm fat-free mass, and these variables were not correlated with local vasodilation within a given exercise intensity. Under the experimental conditions employed, the blunted responses with age reflect impaired local contraction-induced rapid vasodilation.
Collapse
|