Epidemiology and evaluation: steps toward hypertension treatment in the 1990s.

The percentage of persons in the United States over age 65--especially over 85--is increasing more rapidly than other age groups. Two thirds of people over age 65 have blood pressure higher than 140 mm Hg systolic or 90 mm Hg diastolic. Isolated systolic hypertension (systolic blood pressure greater than 160 mm Hg with diastolic blood pressure less than 90 mm Hg) is also highly prevalent. In a number of clinical trials, treatment of diastolic hypertension in the elderly has been shown to be beneficial, although the value of treatment of isolated systolic hypertension is not yet established. The benefit of antihypertensive therapy on the incidence of stroke and heart failure has been clearly established, but prevention of the atherosclerotic complications of high blood pressure (sudden death or myocardial infarction, for example) has not been convincingly demonstrated. Since clinical trials designed to investigate this atherosclerotic complication of hypertension have relied on stepped-care regimens (diuretics and beta blockers), the question arises whether the use of different drugs might have a better effect on prevention of myocardial infarction. The basis for this supposition includes the known adverse effects of diuretics and beta blockers on electrolytes, lipid metabolism, glucose metabolism, insulin resistance, and quality of life. Hypertension treatment in the 1990s will focus on the mechanisms by which blood pressure is lowered by various antihypertensive agents, as well as individualization of drug therapy based on coexisting diseases and conditions. Emphasis will be placed on use of monotherapy whenever possible; diuretics in low doses will probably be used more frequently for second-line therapy. In recognition of their lack of adverse lipid effects and their tolerability, first-line therapy with alpha blockers, angiotensin-converting enzyme inhibitors, and calcium antagonists will become increasingly common. The goal of antihypertensive therapy will be to extend the life expectancy of hypertensive patients to that of subjects without high blood pressure; hopefully, these new treatment approaches will bring us closer to that goal.