REDUCTION IN LONG-TERM ANTIHYPERTENSIVE MEDICATION REQUIREMENTS - EFFECTS OF WEIGHT-REDUCTION BY DIETARY INTERVENTION IN OVERWEIGHT PERSONSWITH MILD HYPERTENSION

Background: Increasing concern over long-term drug treatment of mild h ypertension has stimulated several studies of weight reduction. Phase I of the Trial of Antihypertensive Interventions and Management demons trated a short-term effect of weight loss on blood pressure control in overweight persons with mild hypertension, who were either taking pla cebo or taking low-dose monotherapy. Phase II investigates the long-te rm benefit of weight loss on the ability to maintain blood pressure co ntrol. Methods: From 10 148 community-based screenees, 587 persons (5. 8%), aged 21 to 65 years, entered a multicenter, randomized drug (doub le-blind, placebo-controlled) and diet trial. Participants had a diast olic blood pressure between 90 and 1 00 mm Hg and were at 110% to 160% of their ideal weight. They were randomized to a usual diet (n=296) o r to a weight loss diet (n=291) and within each diet group to placebo, chlorthalidone, 25 mg/d, or atenolol, 50 mg/d. Treatment failure was defined as using additional antihypertensive medications if diastolic blood pressure rose above 90 mm Hg according to protocol-specified cri teria. Results: At baseline, mean diastolic blood pressure was 93 mm H g systolic blood pressure, 143 mm Hg- weight, 88 kg' percent ideal wei ght, 137%; age, 48 years; 56% were men; and 33% were black. Mean follo w-up was 4.5 years. There was a net loss of 2 to 3 kg with weight loss diet compared with usual diet over most of the follow-up period. The 5-year incidence of treatment failure was 56.7 per 100 participants wi th usual diet and 49.8 per 100 with weight loss. Long-term weight loss decreased failure of blood pressure control for those receiving place bo or low-dose diuretic or beta-blocker by 23%. The results were simil ar in direction in each drug group. Conclusions: The Trial of Antihype rtensive Interventions and Management demonstrated that weight reducti on is an effective long-term therapy for maintaining blood pressure in the normal range when used as monotherapy or in combination with eith er thiazide diuretics or beta-blockers. Consequently, weight loss shou ld be recommended for the management of obese individuals with mild hy pertension.