Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 54, Issue 5 B219-B224, Copyright © 1999 by The Gerontological Society of America
Differential effects of aging on heart rate variability and blood pressure variability
L Fluckiger, JM Boivin, D Quilliot, C Jeandel and F Zannad
Clinical Pharmacology and Cardiology, Centre d'Investigation Clinique INSERM-CHU, EA 2403: Insuffisance Cardiaque, Hopital Jeanne d'Arc, Nancy, France.
Previous studies investigating autonomic cardiovascular control in elderly
persons usually included analysis of R-R interval but not of blood pressure
variability. "Physiological" blood pressure rise during the aging process
was not accounted for as a possible confounding factor. This study was
designed to characterize the relationship between age and short-term heart
rate (HR) and blood pressure (BP) variability, independently of the
"physiological" rise in BP associated to aging. The study was carried out
in 65 "normotensive" (BP< or =140/80 mm Hg) healthy subjects, ranging in
age from 18 to 80 years. BP and HR were recorded at rest with a Finapres
device. Low-frequency (LF = 0.066 to 0.129 Hz) and high-frequency (HF =
respiratory peak +/-0.05 Hz) components of HR and BP variability were
assessed using fast- Fourier spectral analysis. Transfer-function analysis
between systolic BP and HR variability permitted the calculation of the
gain of baroreflex sensitivity. Significant results of this study include a
continuous and linear decline with age of normalized LF spectral power of
HR in the standing position and of normalized HF spectral power of HR
during paced breathing. No correlation was found between age and BP
variability, except for LF diastolic BP spectral power in the standing
position. The baroreflex gain was negatively correlated with age. The
effect of aging on autonomic nervous system cardiac control is progressive
and continuous throughout an 18-80 years age range. Although the aging
process diminished HR variability and diastolic BP variability, it had no
influence on systolic BP variability.