Relation of Pulse Wave Velocity to Contemporaneous and Historical Blood Pressure in Female Twins

Abstract

Background: An association between blood pressure and aortic stiffness is well known, but ambiguity remains as to whether one precedes the other. This study aimed to investigate the association of aortic stiffness with contemporaneous versus historic blood pressure and direction of causality between aortic stiffening and hypertension in female twins.

Methods: Aortic stiffness, measured by carotid-femoral pulse wave velocity (PWV), and mean arterial pressure (MAP) was recorded in 2037 female TwinsUK participants (mean age: 62.4±9.7 years) at a single time point. A subset of 947 participants had repeat PWV and MAP measures (mean interval 5.5±1.7 years) with additional historic MAP (mean interval 6.6±3.3 years before baseline).

Results: Cross-sectional multivariable linear regression analysis confirmed PWV significantly associated with age and MAP. In longitudinal analysis, annual progression of PWV was not associated with historic MAP (standardized beta coefficient [β]=-0.02, P=0.698), weakly associated with baseline MAP (β=0.09, P=0.049) but strongly associated with progression (from baseline to most recent measurement) of MAP (β= 0.26, P<0.001). Progression of MAP associated with both baseline and progression of PWV (β=0.13, P=0.003 and β=0.24, P<0.001, respectively).

Conclusions: Progression of aortic stiffness associates more strongly with contemporaneous MAP compared with historic MAP. In contrast, progression of MAP is associated with prior arterial stiffness. These findings suggest a bidirectional relationship between arterial stiffness and blood pressure, and that lowering blood pressure may prevent a cycle of arterial stiffening and hypertension.

Keywords: blood pressure; carotid-femoral pulse wave velocity; hypertension; longitudinal studies; vascular stiffness.

Figure 1.

Schema for study design. A, Timelines for recruitment. B, Flow diagram of subject inclusion and exclusion for the longitudinal cohorts and cross-sectional group. BP indicates blood pressure; and PWV, pulse wave velocity.

Figure 2.

Trajectories of pulse wave velocity (PWV) progression for quintiles of age at baseline. Baseline PWV estimates adjusted for mean arterial pressure and heart rate at baseline; follow-up estimates are adjusted for mean arterial pressure and heart rate at follow-up and time between measurements. Markers represent mean age of the quintile at each timepoint.

Figure 3.

Forest plots of linear regression models examining how the associations of annual progression in pulse wave velocity (PWV_AP) to baseline and/or progression of blood pressure (BP) changes with inclusion of baseline PWV (PWV_B), and baseline and progression of cardiovascular risk factors. A, Association of PWV_AP to baseline BP and cardiovascular risk factors. B, Association of PWV_APto baseline BP and cardiovascular risk factors and PWV_B. C, Association of PWV_AP to baseline and progression of BP and cardiovascular risk factors. D, Association of PWV_AP to baseline and progression of BP and cardiovascular risk factors and PWV_B. Plots show standardized beta coefficients and 95% CIs for association of follow-up pulse wave velocity with baseline (B) and annual progression (AP) of potential explanatory variables. Multivariable analyses were performed using the enter method. Models shown in A and B were additionally adjusted for use of antihypertensive therapy at baseline, use of lipid-lowering therapy at baseline, diabetes at baseline, current smoking at baseline, and time between baseline and follow-up PWV. Models in C and D were additionally adjusted for use of antihypertensive therapy at baseline and follow-up, use of lipid-lowering therapy at baseline and follow-up, diabetes at baseline and follow-up and current smoking at baseline and follow-up. Age_B indicates age at baseline; HR_AP, annual progression in heart rate; HR_B, baseline heart rate; height _AP, annual progression in height; height_B, baseline height; MAP_AP, annual progression in mean arterial pressure; MAP_B, baseline mean arterial pressure; weight_AP, annual progression in weight; and weight_B, baseline weight