PULSE PRESSURE AND RESISTANCE ARTERY STRUCTURE IN THE ELDERLY

There has been recent interest in the possibility that resistance vess el structural adaptation in hypertension may be more closely related t o pulse pressure than to other blood pressure parameters. We investiga ted the relation between blood pressure and resistance vessel structur e in a group of subjects from an age group (older than 60 years) in wh ich a widening of pulse pressure is a typical finding and characterize d blood pressure parameters using 24-hour ambulatory blood pressure mo nitoring. We studied resistance vessels retrieved from biopsies of ski n and subcutaneous fat taken from the gluteal region of 32 subjects un der local anesthesia (age, 70+/-1 years [mean+/-SEM]), 21 of whom were hypertensive and 11 normotensive. Media-lumen ratio was higher in the hypertensive than the normotensive subjects (18.6+/-1.6% versus 12.8/-1.2%, P<.01) and correlated with age (r=.44, P<.05), clinic systolic pressure (r=.35, P<.05), 24-hour systolic pressure (r=.40, P<.05), an d 24-hour pulse pressure (r=.56, P<.001). Stepwise multivariate regres sion analysis identified clinic and 24-hour pulse pressure as the only significant predictors of media-lumen ratio independent of age, other parameters of clinic blood pressure, and blood pressure variability ( R(2)=41%, P<.05). These findings confirm those from animal models of h ypertension in demonstrating the importance of pulse pressure in relat ion to cardiovascular structural adaptation and have important implica tions for the goals of treatment of hypertension in the elderly.