Impact of blood pressure perturbations on arterial stiffness

Abstract

Although the associations between chronic levels of arterial stiffness and blood pressure (BP) have been fairly well studied, it is not clear if and how much arterial stiffness is influenced by acute changes in BP. The primary aim of this study was to determine magnitudes of BP-dependence of various measures of arterial stiffness during acute BP perturbations. Fifty apparently healthy subjects, including 25 young (20-40 years) and 25 older adults (60-80 years), were studied. A variety of BP perturbations, including head-up tilt, head-down tilt, mental stress, isometric handgrip exercise, and cold pressor test, were used in order to encompass blood pressure changes induced by physical, mental, and/or physiological stimuli. Arterial stiffness measures included cardio-ankle vascular index (CAVI), carotid-femoral pulse wave velocity (cfPWV), brachial-ankle pulse wave velocity (baPWV), arterial compliance (AC), elastic modulus (EM), arterial distensibility (AD), beta-stiffness index, and young's modulus (YM). When each index of arterial stiffness was plotted with mean blood pressure, all the arterial stiffness indices, including CAVI (r=0.50), cfPWV (r=0.51), baPWV (r=0.61), AC (r=-0.42), EM (r=0.52), AD (r=-0.32), β-stiffness index (r=0.19), and YM (r=0.35) were related to mean BP (all P<0.01). Changes in CAVI, cfPWV, baPWV, and elastic modulus were significantly associated with changes in mean BP in the pooled conditions. Changes in AC, AD, β-stiffness index, and YM were not significantly related to changes in mean BP. In conclusion, this study demonstrated that blood pressure changes in response to a various forms of pressor stimuli were associated with the corresponding changes in arterial stiffness indices and that the strengths of associations with BP varied widely depending on what arterial stiffness indices were examined.