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.