Effect of ageing on dynamic cerebral autoregulation during head-up tilt

Carey, Brian J., Panerai, Ronney B. and Potter, John F. (2003) Effect of ageing on dynamic cerebral autoregulation during head-up tilt. Stroke, 34 (8). pp. 1871-1875. ISSN 1524-4628

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Abstract

Background and Purpose— Physiological aging is associated with many changes in the cardiovascular and cerebrovascular systems, but dynamic cerebral autoregulation (CA) during supine rest shows no age-related changes. Because syncopal syndromes usually occur during orthostatic stress and their prevalence increases with age, it is important to define the effect of aging on dynamic CA during orthostatic stress. Methods— Twenty-five younger subjects (≤40 years) and 25 sex-matched older subjects (≥60 years) underwent 70° head-up tilt for 30 minutes. Bilateral middle cerebral artery blood flow velocities were measured with transcranial Doppler ultrasound, along with noninvasive continuous measurements of arterial blood pressure, heart rate, and transcutaneous and end-tidal carbon dioxide concentrations. By comparing actual changes in cerebral blood flow velocity to changes predicted by a model based on arterial blood pressure changes, we derived dynamic autoregulatory indexes for each subject for periods before, during, and after tilt. Results— Younger subjects were a mean of 40 years younger than older subjects (28±8 versus 69±10 years). Although cerebral blood flow velocity (P<0.001) and baroreceptor sensitivity (P<0.001) were significantly lower at rest in older subjects, autoregulatory indexes were similar in younger and older subjects at all times before, during, and after tilt (P=0.62). Conclusions— Although increasing age is associated with lower cardiac baroreceptor sensitivity and cerebral blood flow velocity, dynamic CA during orthostatic stress is unaffected by physiological aging.

Item Type:	Article
Faculty \ School:	Faculty of Medicine and Health Sciences > Norwich Medical School
UEA Research Groups:	Faculty of Medicine and Health Sciences > Research Groups > Nutrition and Preventive Medicine Faculty of Medicine and Health Sciences > Research Groups > Cardiovascular and Metabolic Health
Depositing User:	EPrints Services
Date Deposited:	25 Nov 2010 11:09
Last Modified:	29 Aug 2023 15:30
URI:	https://ueaeprints.uea.ac.uk/id/eprint/12285
DOI:	10.1161/01.STR.0000081981.99908.F3

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