Blood pressure levels and risk of cardiovascular disease mortality among Japanese men and women: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study).

ABSTRACT

OBJECTIVE: To examine the association of blood pressure (BP) with cardiovascular mortality in real-world settings and investigate whether that association varied by use of antihypertensive medication at baseline. METHODS: Data from 27 728 Japanese men and women, aged 40-79 years, free of stroke, coronary heart disease, cancer, and kidney disease at entry (1988-1990) were used in this study. Mortality surveillance was completed through 2009, resulting in 449 800 person-years of follow-up. Hazard ratios for cardiovascular mortality were analysed by BP category (based on 2018 European guidelines) at admission. RESULTS: There were 1477 deaths from cardiovascular diseases (CVDs). Relative to high-normal BP at admission, the multivariable hazard ratios (95% confidence intervals) of CVD were 0.85 (0.69-1.04) for optimal BP; 0.96 (0.81-1.15) for normal BP; 1.26 (1.09-1.46) for Grade 1 hypertension; and 1.55 (1.31-1.84) for Grade 2-3 hypertension. A similar linear association was observed among persons not taking antihypertensive medication at admission. Among patients treated for hypertension, a U-shaped association with CVD mortality was observed; hazard ratios = 2.31 (1.25-4.27), 1.68 (1.05-2.69), 1.56 (1.10-2.22), and 1.63 (1.13-2.36), respectively. Similar patterns were observed for stroke and coronary heart disease, although not always statistically significant. CONCLUSION: BP categories at baseline were linearly and positively associated with CVD mortality overall and also among participants not taking antihypertensive medication. A higher risk of mortality from CVD was observed among patients already treated for hypertension with optimal and normal BPs than those with high-normal BP, suggesting the importance of careful monitoring of BP and comorbidities of such patients.