Faculty Collaboration Database

Effects of aging on baroreflex regulation of sympathetic activity in humans. Am J Physiol 1992 Sep;263(3 Pt 2):H798-803

Date

09/01/1992

Pubmed ID

1415605

DOI

10.1152/ajpheart.1992.263.3.H798

Scopus ID

2-s2.0-0026639824 (requires institutional sign-in at Scopus site)   244 Citations

Abstract

Arterial baroreflexes contribute importantly to blood pressure regulation through their influence on parasympathetic outflow to the sinus node and sympathetic outflow to the peripheral circulation. Baroreflex control of heart rate is known to be diminished in older individuals. Whether advancing age is associated with a parallel attenuation in baroreflex control of sympathetic outflow to the peripheral circulation has not been studied in humans. To provide such information, we made direct measurements of muscle sympathetic nerve activity (MSNA) in healthy males who ranged in age from 18 to 71 yr. The subjects were arbitrarily divided into three groups: younger (18-34 yr; n = 35), middle aged (35-50 yr; n = 15), and older (51-71 yr; n = 16). Although basal levels of MSNA were higher in older subjects than in younger and middle-aged subjects, the gains of baroreflex control of MSNA were the same in the older, middle-aged, and younger subjects (-4.6 +/- 0.6, -4.8 +/- 0.9, -5.1 +/- 0.5 U/mmHg, P greater than 0.10). In contrast, the gains of baroreflex control of cardiac intervals were attenuated in the older and middle-aged subjects compared with the younger subjects (9.8 +/- 1.2, 13.6 +/- 1.4, 21.7 +/- 1.3 ms/mmHg, P less than 0.05). Our data indicate that although the parasympathetic component of the arterial baroreflex becomes impaired with advancing age, the sympathetic component can be well maintained in healthy individuals even into the seventh decade.

Author List

Ebert TJ, Morgan BJ, Barney JA, Denahan T, Smith JJ

Author

Thomas J. Ebert MD, PhD Adjunct Professor in the Anesthesiology department at Medical College of Wisconsin

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

Adolescent
Adult
Aged
Aging
Cold Temperature
Forearm
Humans
Immersion
Male
Middle Aged
Muscles
Neck
Pressoreceptors
Pressure
Reflex
Sinus of Valsalva
Suction
Sympathetic Nervous System
Vascular Resistance