Causes, implications, and treatment of systolic hypertension.

Mild hypertension is currently defined as systolic blood pressure between 140 and 160 mm Hg. The prevalence of systolic hypertension (including this mild category) in individuals 65 and older is 21% for men and 23% for women. Risk factors include obesity, excessive sodium and alcohol consumption, and possibly calcium and bone metabolism. Determinants of arterial wall rigidity and subsequent increase in pulse-wave velocity are also clearly factors. Much of the associated disease occurs in individuals with systolic pressures between 140 and 159 mm Hg. A particularly high-risk group appears to be those with an elevated systolic blood pressure and a low diastolic blood pressure. Systolic hypertension has now been found to be related to the progression of peripheral atherosclerosis, with lower progression rates among treated individuals. In addition, the beneficial effects of antihypertensive therapy have been found to be strongest among individuals with evidence of subclinical peripheral atherosclerosis. The high prevalence of mild systolic hypertension and its clear association with atherosclerotic disease suggests that older individuals with early systolic hypertension should be identified and treated. Clinical trials to test the efficacy of such treatment should be a high priority, perhaps in subgroups with early subclinical disease.