Self-measured home blood pressure highlights cardiovascular risk in women: the HOMED-BP study

No studies examined sex differences in relation to the prognostic significance of self-measured home blood pressure (HBP). We compared the predictive power for the risk of cardiovascular events in 1547 women and 1516 men with hypertension using HBP captured at treatment-free baseline and during on-treatment follow-up, based on the Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study. To express the change in risk for the composite cardiovascular endpoint associated with a 1–SD increase in HBP at baseline or on treatment, we derived multivariable-adjusted hazard ratios (HR) based on a Cox regression model. Over a median follow-up of 7.3 years, 100 composite events occurred, including 40 events in women. In women, systolic HBP both at baseline and on-treatment showed significant risk increment (at baseline: HR per 1-SD increment, 1.62; 95% confidence interval [CI], 1.17–2.24. on-treatment: HR, 1.74; 95% CI, 1.32–2.29). However, systolic HBP at baseline did not predict cardiovascular events in men ( P = 0.25). On-treatment HBP was significantly associated with cardiovascular risk ( P ≤ 0.012) irrespective of sex. Nevertheless, the point estimate of HR for systolic HBP in men (1.33) was less than that in women (1.74), and the interaction of sex with 1 SD-increase in systolic HBP in cardiovascular risk was significant irrespective of baseline ( P = 0.039) or follow-up ( P = 0.040) measurement when they were mutually adjusted. The increase in cardiovascular risk with the systolic HBP was steeper in women than in men for both baseline and on-treatment. The current findings unveil the importance of the control of systolic HBP, especially in women. Clinical Trial Registration: UMIN Clinical Trial Registry ( http://www.umin.ac.jp/ctr ), Unique identifier: C000000137.