(Circulation. 2001;104:2424.)
© 2001 American Heart Association, Inc.
Clinical Investigation and Reports |
From the Department of Kinesiology and Applied Physiology, University of Colorado at Boulder (P.P.J., L.F.S., G.A.K., D.R.S.); the Department of Medicine, University of Colorado Health Sciences Center, Denver (L.F.S., R.A.Q., D.R.S.); the Clinical Research Center, Franz Volhard Clinic at the Max Delbrück Center, Medical Faculty of the Charité, Humboldt University, Berlin, Germany (J.J.); and the Autonomic Dysfunction Center, Vanderbilt University, Nashville, Tenn (J.R.S.).
Correspondence to Pamela Parker Jones, PhD, Department of Kinesiology and Applied Physiology, UCB 354, University of Colorado, Boulder, CO 80309. E-mail pamela{at}spot.colorado.edu
Background Primary aging is associated with changes in the autonomic nervous system (ANS), but the functional significance of these changes for systemic circulatory control of arterial blood pressure (BP) is unknown. We tested the hypothesis that ANS support of BP is altered in healthy older humans.
Methods and Results A total of 23 young (aged 24±1 years; systolic/diastolic BP, 126±2/66±1 mm Hg) and 16 older (aged 65±1 years; systolic/diastolic BP, 125±3/62±2 mm Hg) healthy men were studied before and during ganglionic blockade (intravenous trimethaphan). The reduction in mean BP (radial artery catheter) with trimethaphan was almost twice as great in the older men (-33±2 versus -19±2 mm Hg; -40% versus -22% of baseline; P<0.01) due to a lack of increase in heart rate (3±2 versus 25±2 bpm; P<0.001) and cardiac output (-0.42±0.19 versus 1.01±0.26 L/min; P<0.001); the decreases in systemic vascular resistance were not different. The absence of tachycardia in the older men was associated with reduced baseline heart rate variability (HRV, P<0.05); the change in heart rate with trimethaphan correlated with the standard deviation of the R-R intervals (HRVSD R-R interval; r=0.57, P<0.001). Among individual subjects (pooled groups), the reductions in mean BP with trimethaphan were most strongly related to measures of sympathetic activity (r=0.58 to 0.67, P<0.005), change in mean BP with intravenous phenylephrine (r=0.57, P<0.001), and HRVSD R-R interval (r=-0.40, P<0.01).
Conclusions ANS support of BP is altered with age in healthy men due to less cardiac vagal inhibition of heart rate and cardiac output. Basal sympathetic activity and
-adrenergic vascular sensitivity are also key physiological correlates of ANS support of BP in healthy men.
Key Words: nervous system, autonomic cardiac output heart rate
This article has been cited by other articles:
![]() |
E. C. Hart, M. J. Joyner, B. G. Wallin, C. P. Johnson, T. B. Curry, J. H. Eisenach, and N. Charkoudian Age-Related Differences in the Sympathetic-Hemodynamic Balance in Men Hypertension, July 1, 2009; 54(1): 127 - 133. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. C. Hart, N. Charkoudian, B. G. Wallin, T. B. Curry, J. H. Eisenach, and M. J. Joyner Sex Differences in Sympathetic Neural-Hemodynamic Balance: Implications for Human Blood Pressure Regulation Hypertension, March 1, 2009; 53(3): 571 - 576. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Christou and D. R. Seals Decreased maximal heart rate with aging is related to reduced {beta}-adrenergic responsiveness but is largely explained by a reduction in intrinsic heart rate J Appl Physiol, July 1, 2008; 105(1): 24 - 29. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Joyner, N. Charkoudian, and B. G. Wallin A sympathetic view of the sympathetic nervous system and human blood pressure regulation Exp Physiol, June 1, 2008; 93(6): 715 - 724. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. D. Monahan Effect of aging on baroreflex function in humans Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R3 - R12. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Shibao, A. Gamboa, A. Diedrich, A. C. Ertl, K. Y. Chen, D. W. Byrne, G. Farley, S. Y. Paranjape, S. N. Davis, and I. Biaggioni Autonomic Contribution to Blood Pressure and Metabolism in Obesity Hypertension, January 1, 2007; 49(1): 27 - 33. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Masuki, J. H. Eisenach, F. A. Dinenno, and M. J. Joyner Reduced forearm {alpha}1-adrenergic vasoconstriction is associated with enhanced heart rate fluctuations in humans J Appl Physiol, March 1, 2006; 100(3): 792 - 799. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Christou, P. P. Jones, J. Jordan, A. Diedrich, D. Robertson, and D. R. Seals Women Have Lower Tonic Autonomic Support of Arterial Blood Pressure and Less Effective Baroreflex Buffering Than Men Circulation, February 1, 2005; 111(4): 494 - 498. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. R. Seals and F. A. Dinenno Collateral damage: cardiovascular consequences of chronic sympathetic activation with human aging Am J Physiol Heart Circ Physiol, November 1, 2004; 287(5): H1895 - H1905. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Christou, P. Parker Jones, A. E. Pimentel, and D. R. Seals Increased abdominal-to-peripheral fat distribution contributes to altered autonomic-circulatory control with human aging Am J Physiol Heart Circ Physiol, October 1, 2004; 287(4): H1530 - H1537. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Tank, J. Jordan, A. Diedrich, M. Obst, R. Plehm, F. C. Luft, and V. Gross Clonidine Improves Spontaneous Baroreflex Sensitivity in Conscious Mice Through Parasympathetic Activation Hypertension, May 1, 2004; 43(5): 1042 - 1047. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. R. Stratton, W. C. Levy, J. H. Caldwell, A. Jacobson, J. May, D. Matsuoka, and K. Madden Effects of aging on cardiovascular responses to parasympathetic withdrawal J. Am. Coll. Cardiol., June 4, 2003; 41(11): 2077 - 2083. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. D. Christou, P. P. Jones, and D. R. Seals Baroreflex Buffering in Sedentary and Endurance Exercise-Trained Healthy Men Hypertension, June 1, 2003; 41(6): 1219 - 1222. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. P. Jones, D. D. Christou, J. Jordan, and D. R. Seals Baroreflex Buffering Is Reduced With Age in Healthy Men Circulation, April 8, 2003; 107(13): 1770 - 1774. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. P. Jones, L. F Shapiro, G. A Keisling, R. A Quaife, and D. R Seals Is autonomic support of arterial blood pressure related to habitual exercise status in healthy men? J. Physiol., April 15, 2002; 540(2): 701 - 706. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. P. Jones, L. F Shapiro, G. A Keisling, R. A Quaife, and D. R Seals Is autonomic support of arterial blood pressure related to habitual exercise status in healthy men? J. Physiol., April 15, 2002; 540(2): 701 - 706. [Abstract] [Full Text] [PDF] |
||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2001 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |