Home BP variability tied to subclinical atherosclerosis in multiple vascular beds
Greater home blood pressure (BP) variability, particularly in home systolic (S)BP, correlates with higher carotid, aortic and peripheral but not coronary atherosclerosis burdens independent of the mean home BP, suggests a recent study.
The investigators defined SBP and diastolic (D)BP variability in a cross-sectional population-based study of 1,033 Japanese (mean age 64.0 years; 88.7 percent men) without known cardiovascular disease as variability independent of the mean (VIM) across self-measured home BP values during 7 consecutive days and quantified coronary (CAC) and aortic artery calcification (AAC) by computed tomography, carotid intima–media thickness (CIMT) by ultrasonography, and ankle–brachial index (ABI).
Multivariable-adjusted models including mean SBP showed that higher VIM of SBP correlated with CIMT >1.0 mm (relative risk [RR] fourth vs first quartile, 1.71; 95 percent CI, 1.15–2.54), AAC score >0 (RR, 1.08; 1.02–1.15) and ABI <1.1 (RR, 1.49; 1.12–1.97). In addition, linear trends were statistically significant, but no significant association was seen between VIM of SBP and CAC score >0.
On the other hand, higher VIM of DBP correlated only with AAC score >0. Associations were similar when modeling subclinical atherosclerosis severity as continuous outcomes and were consistent across subgroups based on demographics, behavioural and cardiovascular risk factors, according to the investigators.
“The mechanism by which higher BP variability causes cardiovascular events remains unclear. Experimental results indicate that alterations in vessel wall tension related to BP variability may initiate atherosclerosis through oscillatory shear stress,” the investigators said.