Background: We examined the relationship between systolic and diastolic blood pressure (BP) and the incidence of cardiovascular disease (CVD) in a nationally representative cohort of 169,871 men and women > or = 40 years of age in China.
Methods: Data on BP and other variables were obtained at a baseline examination in 1991 using standard protocols. Follow-up evaluation was conducted in 1999-2000, with a response rate of 93.4%.
Results: After adjustment for age, sex, cigarette smoking, alcohol consumption, physical activity, body mass index, education, geographic region, urbanization, and time-dependent history of diabetes, a strong and linear association between both systolic and diastolic BP and incidence of CVD, coronary heart disease and stroke were observed (all P < 0.0001). For example, the relative risks (95% confidence interval (CI)) of CVD incidence were 1.09 (1.00-1.18), 1.25 (1.16-1.35), 1.49 (1.38-1.62), 2.15 (1.99-2.31), 3.01 (2.78-3.27), and 4.16 (3.84-4.51) for those with systolic/diastolic BP of 110-119/75-79, 120-129/80-84, 130-139/85-89, 140-159/90-99, 160-179/100-109, and > or = 180/110 mm Hg compared to those with BP <110/75 mm Hg. Increases in systolic BP were associated with a greater risk of CVD compared to corresponding increases in diastolic BP. The linear trend for increased CVD risk being related to higher BP levels was observed in all subgroups of gender, age, body weight, and cigarette smoking.
Conclusions: Our results indicate that there is a strong, linear, and independent relationship between BP levels and the risk of CVD in Chinese adults. Systolic BP is a stronger predictor of CVD risk compared to diastolic BP.