Influence of Aging and Other Cardiovascular Risk Factors on Baroreflex Sensitivity

OBJECTIVES: To examine the influence of known cardiovascular risk factors (cholesterol, blood glucose levels, arterial pressures, heart rate, and aging) on baroreflex sensitivity. DESIGN: An observational epidemiological study. SETTING: Geriatric Division at the Policlinico Umberto Primo, University of Rome La Sapienza. PARTICIPANTS: Two hundred three subjects whose ages ranged from 9 to 94 years, apparently healthy and free of detectable clinical evidence of atherosclerosis. MEASUREMENTS: All subjects underwent determination of baroreflex sensitivity by phenylephrine infusion (BSphe), and by a noninvasive method derived from spectral analysis of R‐R interval and arterial pressure variabilities (α index). RESULTS: The population, subdivided into tertiles for each variable studied, had lower BSphe values and lower α indexes as a function of age, plasma low‐density lipoprotein (LDL) cholesterol, and systolic blood pressure. The α index was significantly lower in both groups with elevated LDL cholesterol levels than in those with lower levels (II and III vs I tertile, P < .001), whereas BSphe differed significantly only in the two groups who had extreme levels of LDL (I vs III tertile, P < .001). Multiple regression analysis identified a negative association of the α index with age (P < .001), heart rate (P < .01), area under the glucose‐response curve (P < .001), and LDL cholesterol (P < .01), but of BSphe only with age (P < .001) and heart rate (P < .01). CONCLUSION: These findings indicate that some risk factors for coronary heart disease adversely influence baroreflex sensitivity.