Pulse wave velocity is an independent predictor of the longitudinal increase in systolic blood pressure and of incident hypertension in the Baltimore Longitudinal Study of Aging

Abstract

Objectives: This study sought to evaluate whether pulse wave velocity (PWV), a noninvasive index of arterial stiffness, is a predictor of the longitudinal changes in systolic blood pressure (SBP) and of incident hypertension.

Background: Although arterial stiffness is believed to underlie, in part, the age-associated changes in SBP, particularly at older ages, few longitudinal studies in humans have examined the relationship between arterial stiffness and blood pressure.

Methods: Pulse wave velocity was measured at baseline in 449 normotensive or untreated hypertensive volunteers (age 53 +/- 17 years). Repeated measurements of blood pressure were performed during an average follow-up of 4.9 +/- 2.5 years.

Results: After adjusting for covariates including age, body mass index, and mean arterial pressure, linear mixed effects regression models showed that PWV was an independent determinant of the longitudinal increase in SBP (p = 0.003 for the interaction term with time). In a subset of 306 subjects who were normotensive at baseline, hypertension developed in 105 (34%) during a median follow-up of 4.3 years (range 2 to 12 years). By stepwise Cox proportional hazards models, PWV was an independent predictor of incident hypertension (hazard ratio 1.10 per 1 m/s increase in PWV, 95% confidence interval 1.00 to 1.30, p = 0.03) in individuals with a follow-up duration greater than the median.

Conclusions: Pulse wave velocity is an independent predictor of the longitudinal increase in SBP and of incident hypertension. This suggests that PWV could help identify normotensive individuals who should be targeted for the implementation of interventions aimed at preventing or delaying the progression of subclinical arterial stiffening and the onset of hypertension.

Figure 1. Baseline and Predicted 10-Year Longitudinal Changes in SBP

Baseline and predicted 10-year longitudinal changes in systolic blood pressure (SBP) for men with starting ages 40 years (A) and 70 years (B) whose pulse wave velocity (PWV) at baseline was in the highest versus lowest quartile. For both starting ages, men whose baseline PWV was in the highest quartile showed an accelerated increase in SBP compared with men whose PWV was in the lowest quartile. Quartiles of PWV were separately defined for each age-decade.

Figure 2. Adjusted Hypertension-Free Survival Curves for Participants Who Were Followed Up for >4.3 Years

All participants were normotensive at 4.3 years and were stratified according to median PWV (5.8 m/s). The curves are adjusted for age, SBP, and high-density lipoprotein (HDL). Abbreviations as in Figure 1.