Objective: To determine the risk of death from coronary heart disease, stroke, all cardiovascular disease and all-cause mortality associated with systolic blood pressure and in particular with isolated systolic hypertension among the middle-aged population.
Methods and design: A prospective 15-year cohort study of two independent cross-sectional random samples of subjects participating in baseline surveys in 1972 and 1977. Each survey included a self-administered questionnaire, measurements of height, weight and blood pressure and the determination of the serum cholesterol concentration.
Setting: North Karelia and Kuopio provinces in eastern Finland. Mortality follow-up complete with the personal identification number.
Participants: Participants were 10,333 men and 11,160 women aged 25-64 years without histories of myocardial infarction and stroke incidence at the time of the baseline survey. Isolated systolic hypertension in these analyses was defined as systolic blood pressure > or = 160 mmHg and diastolic blood pressure < 95 mmHg. Subjects with blood pressure < 160/90 mmHg were considered normotensive.
Results: Coronary heart disease, stroke, cardiovascular disease and all-cause mortality among men and women aged 45-64 years increased with the increasing systolic blood pressure. Among women aged 45-64 years, isolated systolic hypertension increased the relative risk of these fatal events. Among men aged 45-64 years, only coronary heart disease mortality was significantly associated with isolated systolic hypertension.
Conclusion: Isolated systolic hypertension is an important predictor of death from coronary heart disease, stroke, cardiovascular disease and all causes for women. For men aged 45-64 years, the risk of death from coronary heart disease was associated with isolated systolic hypertension, but the risk of stroke, cardiovascular disease and all-cause mortality associated with increasing systolic blood pressure was evident already at the systolic blood pressure levels < 160 mmHg, independently of the level of diastolic blood pressure.