Isolated systolic hypertension and its relationship to the risk of myocardial infarction, cerebrovascular disease and death in a middle-aged population.

The prevalence of hypertension in general and of those complications associated with isolated systolic hypertension (at least 165 mmHg systolic and less than 95 mmHg diastolic pressure) were assessed in a random sample of 3888 men and 4336 women aged 30-59 years at the beginning of the study. The prevalence of isolated systolic hypertension was about 5% both in men and women aged 30 to 49 years; in those aged 50 to 59 years the prevalence was 7% in men and 13% in women. Systolic hypertension was associated with an increased risk of acute myocardial infarction (AMI), cerebrovascular stroke and death both in men and women in the seven-year follow-up period. The relative risk of AMI in men and women with isolated systolic hypertension was 1.65 (P less than 0.05) and 0.87, respectively, and the relative risk of stroke 0.57 and 1.29, respectively. Isolated systolic hypertension is not uncommon in the middle-aged population and its impact on cardiovascular complications seems to be significant not only on the elderly but also in the middle-aged.