Effects of Aging on Blood Pressure Variability in Resting Conditions

Abstract

The objective of this study was to determine the effect of aging on beat-to-beat blood pressure and pulse interval variability in resting conditions and to determine the effect of aging on the sympathetic and vagal influence on the cardiovascular system by power spectral analysis of blood pressure and pulse interval. We studied three groups of healthy, normotensive subjects: young (10 to 15 years, n=16), adult (20 to 40 years, n=16), and elderly (70 to 90 years, n=25). Beat-to-beat blood pressure was measured by Finapres during 20 minutes supine and 10 minutes standing. Overall systolic and diastolic blood pressures and pulse interval variability were determined as SD and as coefficient of variation. Also, relative powers of the mid-frequency (0.08 to 0.12 Hz) and high-frequency bands (0.15 to 0.40 Hz) were determined by spectral analysis. In these subjects no differences in blood pressure variability (either as SD or coefficient of variation) were found between age groups, except for the coefficient of variation of standing diastolic blood pressure, which decreased A biological parameters display a certain variability. Cardiovascular parameters such as blood pressure and heart rate distinguish themselves from many others because their variability has (patho)-physiological significance.1 The study of beat-to-beat blood pressure and heart rate variabilities enhances the physiological understanding of neurocardiovascular regulation 2 " 6 ; from a clinical point of view, interest is currently focused on the possible role of blood pressure variability as a risk factor of hypertensive target-organ damage, independent of the average level of blood pressure. 7 Presently, the elderly constitute a large and fastgrowing proportion of the population that challenges cardiovascular research. Like hypertension, aging has been shown to increase blood pressure variability. 810Heart rate variability, however, decreases with increasing age and blood pressure. 8 -91112 Because blood pressure rises with aging, 13 there is a substantial covariance, which makes the relative contribution of blood pressure and aging to variability difficult to disentangle. Other factors that may hamper proper understanding of studies on beat-to-beat blood pressure and heart rate variabilities in relation to age are Received August 10, 1993; accepted in revised form April 13, 1994.From the Departments of Medicine and Physiology (J.M.K.), Academic Medical Centre, Amsterdam, the Netherlands.Correspondence to G.A. van Montfrans, MD, Department of Medicine, Room B2-229, Academic Medical Centre, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.© 1994 American Heart Association, Inc.with aging. Pulse interval variability decreased with aging. Power of the mid-frequency band of systolic and diastolic blood pressures was markedly decreased in the elderly, especially in the standing position. Power of the high-frequency band of pulse interval was also decreased in the elderly. Baroreflex sensitivity calculated by fast Fourier transformation spectral...

Baroreflex Buffering Is Reduced With Age in Healthy Men

“…Breathing frequency was not regulated, but did not differ between young and older groups (18Ϯ2 versus 16Ϯ2 breaths/min, respectively, Pϭ0.49). Cardiovagal baroreflex sensitivity was determined from incremental bolus doses of phenylephrine (25,50, 100, and 200 g) administered at 3-minute intervals. R-R intervals were regressed against the corresponding transient increase in systolic blood pressure (SBP) induced by the phenylephrine bolus.…”

“…14,15,22 Briefly, after a stable 30-minute period, baseline measurements were obtained followed by blockade of N N -cholinergic receptors via continuous intravenous infusion of trimethaphan (Cambridge Laboratories Limited). Complete cardiovascular-autonomic blockade was documented by absence of a change in heart rate in response to bolus injection of phenylephrine (25,50, and/or 100 g). After a 20-minute washout period, baseline measurements were repeated.…”

Spectral analysis of heart rate variability in elderly non-dipper hypertensive patients

“…7,8 In the elderly, changes in spectral Table 2 Heart rate variability and heart rate in the study groups (rest) components induced by standing were more difficult to determine with a Fast Fourier Transform algorithm, probably as a consequence of the reduced variance and the low signal-to-noise ratio. [9][10][11][12] The effect of aging on beat-to-beat blood pressure (BP), pulse interval variability in resting condition, and sympathetic-parasympathetic influence on cardiovascular system evaluated by of BP and pulse interval power spectral analysis, was determined by Veerman et al 13 In this study pulse interval variability was found blunted with aging; the power of mid-frequency band (systolic and diastolic BPs) was markedly lower in the elderly and so was the power of the high frequency of pulse interval. As regards baroreflex sensitivity, calculated by Fast Fourier Transform, it was affected by aging.…”

Effects of age and gender on ambulatory blood pressure and heart rate

“…6,9-12 However, Veerman and colleagues 13 reported no change in BP variability with aging. It is thought that the age-related changes in variability are associated with alterations in the baroreflex and sympathetic/ parasympathetic control of the cardiovascular system.…”