Isolated systolic hypertension in the elderly.

Results of prospective cohort epidemiological studies in different population groups indicate a constant positive and graded association between the level of systolic blood pressure and subsequent mortality from cardiovascular diseases and stroke, especially with advancing age, and irrespective of the level of diastolic blood pressure. Thus, isolated systolic hypertension in the elderly, defined as systolic blood pressure greater than or equal to 160 mmHg and diastolic blood pressure less than 90 mmHg, is a powerful risk factor for mortality and morbidity. In the Hypertension Detection and Follow-Up Program (HDFP), the multiple logistic analysis of the impact of isolated systolic hypertension on 8-year mortality showed that, in the age group 60-69 years, after adjustment for other factors, there was about a 1% increase in mortality each year for every 1-mmHg increase in systolic blood pressure (P less than 0.05). Similarly, among those screened during the Multiple Risk Factor Intervention Trial (MRFIT), aged 55 years and above, the relative risk of stroke mortality in those with isolated systolic hypertension was 3.0, with a 95% confidence interval of 1.3 to 6.8. The United States National Health Survey data estimate the prevalence of isolated systolic hypertension as 8.5% in the age group 65-74 years. The prevalence of isolated systolic hypertension rises significantly with age (6%, 11% and 18%, respectively in the age groups 60-69, 70-79 and above 80 years). Although treatment of diastolic hypertension in the elderly has been shown to be effective in reducing mortality, no adequate prospective evaluation has yet been completed to determine the efficacy of drug treatment of isolated systolic hypertension. Thus, the question of the efficacy of treatment remains unanswered.(ABSTRACT TRUNCATED AT 250 WORDS)