Linear relationship between blood pressure and stroke: the Jichi Medical School Cohort Study.

Hypertension is a major risk for stroke; a linear or J-shaped relationship between blood pressure (BP) and stroke have been reported. The authors examined the relationship between systolic and diastolic BP and risk of stroke in the general population in Japan. The study included 11,097 men and women who were divided into quintiles by systolic BP and diastolic BP in each sex. Follow-up duration was 10.7 years. In men, risks of second to fifth quintiles of systolic BP for all stroke were 1.5 (95% confidence interval [CI], 0.7-3.0), 2.2 (CI, 1.2-4.2), 3.0 (CI, 1.7-5.5), and 4.2 (CI, 2.4-7.6) compared with a reference of the first quintile using Cox's proportional hazard model, respectively. In women, risk of second to fifth quintiles of systolic BP for all stroke were 1.2 (95% CI, 0.6-2.4), 1.5 (CI, 0.8-2.9), 2.2(CI, 1.2-4.1), and 3.1 (CI, 1.7-5.6), respectively. Systolic BP and diastolic BP were related to stroke incidence linearly in the general Japanese population. Systolic BP was slightly more predictive of the risk of stroke than diastolic BP.