Do older adults with higher daily ambulatory activity have lower central blood pressure?

Abstract

We aimed to test the hypothesis that central blood pressure (BP) would be lower in healthy older adults with greater daily ambulatory activity. Forty-three (24 women, 19 men) older adults wore a triaxial accelerometer at the hip for 1week. The volume of ambulatory activity was estimated by average steps per day. As a proxy of intensity of ambulatory activity, 1-min peak step accumulation, or the maximum number of steps taken within a minute was averaged from each day. Participants were considered "active" if they had >7500 steps per day or >105 steps per min. Radial arterial tonometry was used to estimate central (aortic) BP from pulse wave analysis. After adjusting for age and sex, adults with higher steps per day (n=18) tended to have lower central pulse pressure (p=0.08). Interestingly, adults with higher peak step accumulation (n=25) had significantly lower central pulse pressure (40.4±1.6 vs. 46.8±2.0mmHg; p=0.02) after adjusting for age and sex. Stepwise regression including age, sex, body mass index, and peak step accumulation found body mass index to be the strongest predictor of central systolic BP [β=0.42, 95% CI (0.13, 0.70), p=0.004] while peak step accumulation was the strongest predictor of central pulse pressure [β=-0.31, 95% CI (-0.01, -0.60), p=0.043]. These results find older adults with an "active" daily walking pattern, particularly having a higher number of maximal steps in a minute, have lower central pulse pressure than older adults with lower daily ambulatory activity.