Age-Related Changes of Sympathetic Outflow to Muscles in Humans

Iwase, Satoshi; Mano, Tadaaki; Watanabe, Takemasa; Saito, Mitsuru; Kobayashi, Fumio

doi:10.1093/geronj/46.1.m1

Cited by 144 publications

(68 citation statements)

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“…To this end, the present investigation examined sympathetic nervous system activation in healthy young and older adults using a standardized whole body skin surface cooling protocol via water-perfused suit (3,30,51,55). Consistent with a wide body of literature examining MSNA at rest in older adults at thermoneutrality (27,39,53), older adults in the present study exhibited increases in basal muscle sympathetic outflow. Furthermore, whole body cold stress elicited pronounced increases in MSNA burst frequency and strength in older, but not young, adults.…”

Section: Discussionsupporting

confidence: 60%

“…MSNA and plasma norepinephrine concentrations are elevated with advancing age (15,24,27,39,53); therefore, impairments in norepinephrine-mediated vasoconstriction have generally been attributed to sustained agonist-mediated desensitization in ␣-adrenergic receptor responsiveness (24). Conversely, the age-related increase in MSNA during cooling may be a compensatory response as a result of age-associated reductions in ␣-adrenergic receptor responsiveness.…”

Section: Discussionmentioning

confidence: 99%

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Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults

Greaney

Stanhewicz

Kenney

et al. 2014

Journal of Applied Physiology

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Greaney JL, Stanhewicz AE, Kenney WL, Alexander LM. Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults. J Appl Physiol 117: 648 -657, 2014. First published August 7, 2014 doi:10.1152/japplphysiol.00516.2014.-Cardiovascular mortality increases in cold weather in older adults, and physical activity may impart even greater cardiovascular risk than cold exposure alone. Human aging is associated with exaggerated pressor responses to whole body cooling; however, the sympathetic response to cold stress alone and in combination with isometric exercise is unknown. We hypothesized that cold stress would 1) increase muscle sympathetic nerve activity (MSNA) and 2) augment the MSNA response to isometric handgrip in older adults. Whole body cooling (water-perfused suit) was conducted in 11 young (23 Ϯ 1 yr) and 12 healthy older adults (60 Ϯ 2 yr). Blood pressure (BP; Finometer) and MSNA (microneurography) were measured throughout cooling and during isometric handgrip at 30% maximal voluntary contraction performed at a mean skin temperature (T sk) of 34 and 30.5°C. MSNA was greater in older adults at T sk ϭ 34.0°C and throughout cooling (P Ͻ 0.05). MSNA increased during cooling in older, but not young, adults (young: ⌬0 Ϯ 1 vs. older: ⌬8 Ϯ 1 bursts/min; P Ͻ 0.05). The cooling-induced increase in BP was greater in older adults (P Ͻ 0.05). During handgrip, the increases in MSNA and BP were not different between conditions in either young (⌬14 Ϯ 2 T sk 34°C vs. ⌬12 Ϯ 3 Tsk 30.5°C bursts/min; ⌬20 Ϯ 3 Tsk 34°C vs. ⌬19 Ϯ 3 Tsk 30.5°C mmHg; both P Ͼ 0.05) or older adults (⌬12 Ϯ 1 Tsk 34°C vs. ⌬8 Ϯ 1 Tsk 30.5°C bursts/min; ⌬18 Ϯ 3 Tsk 34°C vs. ⌬17 Ϯ 2 Tsk 30.5°C mmHg; both P Ͼ 0.05). In summary, MSNA increased during cold stress in older, but not young, adults. Furthermore, concomitant cold stress did not alter the sympathetic responses to isometric exercise in either age group, suggesting preserved sympathetic responsiveness during exercise in the cold in healthy aging. blood pressure; aging; handgrip; whole body cooling AGING IS A PRIMARY RISK FACTOR for cardiovascular disease, the leading cause of death in the United States (18). Furthermore, cardiovascular-related morbidity and mortality increase at low ambient temperatures, especially in older adults (5,38,44,50,63). The acute systemic physiological responses to cold exposure include peripheral and visceral vasoconstriction, elevated plasma norepinephrine, and increased blood pressure (BP) (9,52,62). Therefore, alterations in the acute responses to cold may contribute to the clinical relation between cold temperatures and increased cardiovascular-related mortality in primary aging. Perturbations that further challenge systemic physiological function during cold exposure, such as static or dynamic exercise, may result in increased sympathetic activation and excessive increases in BP, imparting even greater risk for an acute cardiovascular event in older adults. As such, understanding age-related changes in the acute sympathetic and...

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Section: Discussionsupporting

confidence: 60%

Section: Discussionmentioning

confidence: 99%

Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults

Greaney

Stanhewicz

Kenney

et al. 2014

Journal of Applied Physiology

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“…46 As the increase in peripheral resistance upon standing is mediated by the sympathetic nervous system, 22 it seems that in elderly subjects the sympathetic activation is larger than in young subjects. However, the increase in microneurographically recorded muscle sympathetic nerve activity induced by orthostatic stress was much smaller in elderly subjects than in young subjects, 44 but the increase in circulating catecholamines upon standing was larger in elderly than young subjects. 47 -48 Thus, catecholamines and total peripheral resistance upon standing suggest an increase in sympathetic activity in the elderly.…”

Section: Spectral Analysismentioning

confidence: 78%

“…44 - 45 The evidence concerning the increase in sympathetic nerve activity during orthostatic stress is conflicting. In an earlier study we found that in the same subjects after 10 minutes of standing, compared with by guest on May 12, 2018 http://hyper.ahajournals.org/ Downloaded from being supine, the increase in peripheral resistance was much larger in elderly than young subjects.…”

Section: Spectral Analysismentioning

confidence: 99%

Effects of Aging on Blood Pressure Variability in Resting Conditions

Veerman¹,

Imholz²,

Wieling³

et al. 1995

Survey of Anesthesiology

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The objective of this study was to determine the effect of aging on beat-to-beat blood pressure and pulse interval variability in resting conditions and to determine the effect of aging on the sympathetic and vagal influence on the cardiovascular system by power spectral analysis of blood pressure and pulse interval. We studied three groups of healthy, normotensive subjects: young (10 to 15 years, n=16), adult (20 to 40 years, n=16), and elderly (70 to 90 years, n=25). Beat-to-beat blood pressure was measured by Finapres during 20 minutes supine and 10 minutes standing. Overall systolic and diastolic blood pressures and pulse interval variability were determined as SD and as coefficient of variation. Also, relative powers of the mid-frequency (0.08 to 0.12 Hz) and high-frequency bands (0.15 to 0.40 Hz) were determined by spectral analysis. In these subjects no differences in blood pressure variability (either as SD or coefficient of variation) were found between age groups, except for the coefficient of variation of standing diastolic blood pressure, which decreased A biological parameters display a certain variability. Cardiovascular parameters such as blood pressure and heart rate distinguish themselves from many others because their variability has (patho)-physiological significance.1 The study of beat-to-beat blood pressure and heart rate variabilities enhances the physiological understanding of neurocardiovascular regulation 2 " 6 ; from a clinical point of view, interest is currently focused on the possible role of blood pressure variability as a risk factor of hypertensive target-organ damage, independent of the average level of blood pressure. 7 Presently, the elderly constitute a large and fastgrowing proportion of the population that challenges cardiovascular research. Like hypertension, aging has been shown to increase blood pressure variability. 810Heart rate variability, however, decreases with increasing age and blood pressure. 8 -91112 Because blood pressure rises with aging, 13 there is a substantial covariance, which makes the relative contribution of blood pressure and aging to variability difficult to disentangle. Other factors that may hamper proper understanding of studies on beat-to-beat blood pressure and heart rate variabilities in relation to age are Received August 10, 1993; accepted in revised form April 13, 1994.From the Departments of Medicine and Physiology (J.M.K.), Academic Medical Centre, Amsterdam, the Netherlands.Correspondence to G.A. van Montfrans, MD, Department of Medicine, Room B2-229, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.© 1994 American Heart Association, Inc.with aging. Pulse interval variability decreased with aging. Power of the mid-frequency band of systolic and diastolic blood pressures was markedly decreased in the elderly, especially in the standing position. Power of the high-frequency band of pulse interval was also decreased in the elderly. Baroreflex sensitivity calculated by fast Fourier transformation spectral...

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“…The muscle blood flow represents only 15-20% of the resting cardiac output, but during maximal exercise increases to approximately 85% of total cardiac output. With aging, neural activity [60][61][62] and endothelin-1 concentration 63) increase, while endothelial function [64][65][66] , aortic distensibility 67) , and capillary number decrease 8-11) . Moreover, erythrocyte-mediated ATP release, which mediates vasodilation during conditions of erythrocyte deoxygenation, decreases with aging 68) .…”

Section: Loss Of Blood Flow Volume With Agingmentioning

confidence: 99%

Link between blood flow and muscle protein metabolism in elderly adults

Zempo

Isobe

Naito

2017

JPFSM

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The mechanism which causes sarcopenia, a loss of muscle mass and strength with aging, remains unclear. Muscle mass is controlled by the net balance between protein synthesis and breakdown; however, net balance differences in the basal state do not contribute to sarcopenia. On the other hand, anabolic resistance, a reduction in muscle protein synthesis in response to protein intake, does seem to be involved in sarcopenia. Muscles which are subject to anabolic resistance do not show incremental blood flow volume during the fed-state. Because the vascular system transports amino acids and other nutrients that are essential for muscle protein synthesis, blood flow volume may be a regulator of anabolic resistance. There is some evidence of a link between blood flow and muscle protein metabolism. In addition, a combination of resistance training and amino acid supplementation promotes a positive net protein balance. Resistance training improves, and detraining reduces blood flow volume; therefore, blood flow volume may be involved as a background mechanism for sarcopenia. Moreover, previous studies have shown that sodium nitroprusside, a vasodilatory nitric oxide donor, enhances muscle protein synthesis. Conversely, angiotensin II, a major vasoconstrictive peptide, induces skeletal muscle protein breakdown. In this review, we discuss a possible role for blood flow in skeletal muscle protein metabolism in elderly adults. The regulation of blood flow may prove to be a beneficial treatment for sarcopenia.

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Age-Related Changes of Sympathetic Outflow to Muscles in Humans

Cited by 144 publications

References 0 publications

Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults

Muscle sympathetic nerve activity during cold stress and isometric exercise in healthy older adults

Effects of Aging on Blood Pressure Variability in Resting Conditions

Link between blood flow and muscle protein metabolism in elderly adults

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