King's College London

Background
An association between blood pressure (BP) 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 BP 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, PConclusions
Progression of aortic stiffness associates more strongly with contemporaneous MAP compared to historic MAP. In contrast, progression of MAP is associated with prior arterial stiffness. These findings suggest a bi-directional relationship between arterial stiffness and BP, and that lowering BP may prevent a cycle of arterial stiffening and hypertension.