Faculty Collaboration Database

Sympathetic neural reactivity to stress does not increase with age in healthy humans. Am J Physiol 1994 Jul;267(1 Pt 2):H344-53

Date

07/01/1994

Pubmed ID

8048600

DOI

10.1152/ajpheart.1994.267.1.H344

Scopus ID

2-s2.0-0028031536 (requires institutional sign-in at Scopus site)   114 Citations

Abstract

Sympathetic nervous system reactivity to stress is though to increase with age in humans. We tested this hypothesis by recording postganglionic sympathetic nerve activity to skeletal muscle (MSNA) (peroneal microneurography) and by measuring plasma norepinephrine concentrations (PNE), heart rate, and arterial pressure before (prestress control) and during cognitive challenge (mental arithmetic and colored word test), thermal stress (i.e., the cold pressor test), and exhaustive isometric handgrip exercise (40% of maximum voluntary force)/postexercise ischemia in 15 older (60-74 yr, mean +/- SE = 64 +/- 1) and 15 young (19-30 yr, mean +/- SE = 25 +/- 1) healthy men and women (8 males, 7 females each). The initial prestress control level of MSNA was higher in the older subjects (P < 0.01 vs. young), but there were no significant differences for PNE, heart rate, or arterial pressure. The MSNA and PNE responses to mental stress were small and not different in the two groups. MSNA and PNE increased markedly in response to the cold pressor test and isometric handgrip exercise/post exercise ischemia in both groups. The absolute unit increases in MSNA were similar in the two groups, but the relative (percentage) increases were actually smaller in the older subjects (P < 0.05 vs. young) due to their elevated baseline levels. The stress-evoked increases in arterial pressure were similar in the groups, but the older subjects tended to demonstrate smaller increases in heart rate. In general, no gender differences were noted in either age group. These findings fail to support the long-held concept that stress-induced sympathetic nervous system stimulation becomes exaggerated with age. Thus, sympathetic neural hyperreactivity does not appear to be a fundamental property of the aging process in humans.

Author List

Ng AV, Callister R, Johnson DG, Seals DR

Author

Alexander V. Ng PhD Associate Professor in the Exercise Science department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adult
Aging
Blood Pressure
Cold Temperature
Female
Hand
Humans
Isometric Contraction
Male
Mathematics
Muscles
Physical Exertion
Reference Values
Stress, Psychological
Sympathetic Nervous System