HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 96/6/2333    most recent 00444.2003v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Laitinen, T. Articles by Hartikainen, J. Search for Related Content PubMed PubMed Citation Articles by Laitinen, T. Articles by Hartikainen, J.

HIGHLIGHTED TOPICS
Physiology of Aging

Age dependency of cardiovascular autonomic responses to head-up tilt in healthy subjects

¹Department of Clinical Physiology and Nuclear Medicine, and ²Department of Medicine, Kuopio University and Kuopio University Hospital, FIN-70211 Kuopio, Finland; and ³Laboratoire de Physiologie de l'Environnement, Faculté de Médecine Grange Blanche, Universite Claude Bernard, and Hospices Civils de Lyon, Hôpital E. Herriot, 69373 Lyon Cedex 08, France

Submitted 1 May 2003 ; accepted in final form 28 January 2004

In elderly subjects, heart rate responses to postural change are attenuated, whereas their vascular responses are augmented. Altered strategy in maintaining blood pressure homeostasis during upright position may result from various cardiovascular changes, including age-related cardiovascular autonomic dysfunction. This exploratory study was conducted to evaluate impact of age on cardiovascular autonomic responses to head-up tilt (HUT) in healthy subjects covering a wide age range. The study population consisted of 63 healthy, normal-weight, nonsmoking subjects aged 23–77 yr. Five-minute electrocardiogram and finger blood pressure recordings were performed in the supine position and in the upright position 5 min after 70° HUT. Stroke volume was assessed from noninvasive blood pressure signals by the arterial pulse contour method. Heart rate variability (HRV) and systolic blood pressure variability (SBPV) were analyzed by using spectral analysis, and baroreflex sensitivity (BRS) was assessed by using sequence and cross-spectral methods. Cardiovascular autonomic activation during HUT consisted of decreases in HRV and BRS and an increase in SBPV. These changes became attenuated with aging. Age correlated significantly with amplitude of HUT-stimulated response of the high-frequency component (r = -0.61, P < 0.001) and the ratio of low-frequency to high-frequency power of HRV (r = -0.31, P < 0.05) and indexes of BRS (local BRS: r = -0.62, P < 0.001; cross-spectral baroreflex sensitivity in the low-frequency range: r = -0.38, P < 0.01). Blood pressure in the upright position was maintained well irrespective of age. However, the HUT-induced increase in heart rate was more pronounced in the younger subjects, whereas the increase in peripheral resistance was predominantly observed in the older subjects. Thus it is likely that whereas the dynamic capacity of cardiac autonomic regulation decreases, vascular responses related to vasoactive mechanisms and vascular sympathetic regulation become augmented with increasing age.

autonomic nervous system; baroreflex sensitivity; blood pressure variability; heart rate variability

This article has been cited by other articles:

				J. T. Groothuis, D. H. J. Thijssen, M. Kooijman, R. Paulus, and M. T. E. Hopman Attenuated peripheral vasoconstriction during an orthostatic challenge in older men Age Ageing, November 1, 2008; 37(6): 680 - 684. [Abstract] [Full Text] [PDF]

				Q. Fu, W. Vongpatanasin, and B. D. Levine Neural and Nonneural Mechanisms for Sex Differences in Elderly Hypertension: Can Exercise Training Help? Hypertension, November 1, 2008; 52(5): 787 - 794. [Full Text] [PDF]

				M. Iacoviello, P. Guida, C. Forleo, S. Sorrentino, L. D'Alonzo, and S. Favale Impaired arterial baroreflex function before nitrate-induced vasovagal syncope during head-up tilt test Europace, October 1, 2008; 10(10): 1170 - 1175. [Abstract] [Full Text] [PDF]

				G. Fuca, M. Dinelli, L. Gianfranchi, S. Bressan, C. Lamborghini, and P. Alboni Do subjects with vasovagal syncope have subtle haemodynamic alterations during orthostatic stress? Europace, June 1, 2008; 10(6): 751 - 759. [Abstract] [Full Text] [PDF]

				M. M. Madsen, H. M. Sondergaard, M. Bottcher, N. H. Buus, O. Schmitz, H. E. Botker, and T. T. Nielsen Impact of Type 2 Diabetes on Nitric Oxide and Adrenergic Modulation of Myocardial Perfusion Diabetes, February 1, 2007; 56(2): 468 - 475. [Abstract] [Full Text] [PDF]

				L. A. Lipsitz, I. Iloputaife, M. Gagnon, D. K. Kiely, and J. M. Serrador Enhanced Vasoreactivity and Its Response to Antihypertensive Therapy in Hypertensive Elderly Women Hypertension, March 1, 2006; 47(3): 377 - 383. [Abstract] [Full Text] [PDF]

				Q. Fu and B. D. Levine Hypertension and Antihypertensive Therapy in Elderly Women: How Much Do We Really Know? Hypertension, March 1, 2006; 47(3): 323 - 324. [Full Text] [PDF]

				S. Umehara, M. Tanaka, and T. Nishikawa Effects of Sevoflurane Anesthesia on Carotid-Cardiac Baroreflex Responses in Humans Anesth. Analg., January 1, 2006; 102(1): 38 - 44. [Abstract] [Full Text] [PDF]

				P. A. Gould, M. Yii, M. D. Esler, J. M. Power, and D. M. Kaye Atrial fibrillation impairs cardiac sympathetic response to baroreceptor unloading in congestive heart failure Eur. Heart J., December 1, 2005; 26(23): 2562 - 2567. [Abstract] [Full Text] [PDF]

				D. S. Ditor, M. V. Kamath, M. J. MacDonald, J. Bugaresti, N. McCartney, and A. L. Hicks Effects of body weight-supported treadmill training on heart rate variability and blood pressure variability in individuals with spinal cord injury J Appl Physiol, April 1, 2005; 98(4): 1519 - 1525. [Abstract] [Full Text] [PDF]