To examine the role of dietary sodium reduction with and without potassium supplementation in controlling blood pressure in hypertensive men.

BACKGROUND:

Appropriately increased interest and concern about high blood pressure as a major public health problem coincided with the indication that the risks of hypertension-related morbidity and mortality could be reduced by reduction of blood pressure. Consensus suggestions that individualized approaches be used in treating patients with mild hypertension stimulated further investigations of non-pharmacological methods. Such investigations were also of considerable interest in relation to understanding the physiology of blood pressure control as well as the development of less costly non-drug therapies. Interest was heightened by information suggesting that there might be distinctly harmful side effects related to antihypertensive drug therapy, particularly thiazide diuretics, in some settings. Studies of non-drug therapies included dietary modifications primarily involving weight reduction and sodium restriction with increasing recent concern about other factors such as alcohol intake, dietary fat, calcium, magnesium, and potassium intake.

DESIGN NARRATIVE:

Randomized, double-blind. One hundred forty-five subjects were randomized into a low sodium placebo group in which sodium intake was restricted to no more than 80 mEq/day, 142 subjects into a potassium supplementation (96 mEq/day) group whose sodium intake was also restricted to no more than 80 mEq/day. After 12 weeks of intervention, antihypertensive drugs were withdrawn. Follow-up of each participant was for at least two years. The primary endpoint was the proportion of subjects requiring antihypertensive medication at various points following randomization.

Men, ages 45 to 68. Subjects were hypertensive, were treated for at least 3.5 years with antihypertensive drugs and whose diastolic blood pressure was less than 90 mm Hg.