Effects of weight loss and sodium reduction intervention on blood pressure and hypertension incidence in overweight people with high-normal blood pressure. The Trials of Hypertension Prevention, phase II. The Trials of Hypertension Prevention Collaborative Research Group

OBJECTIVE: To provide a firmer basis for preventing high blood pressure (BP), we tested interventions to promote weight loss, dietary sodium reduction, and their combination for lowering diastolic BP, systolic BP, and the incidence of hypertension during a 3- to 4-year period. METHODS: We conducted a randomized, 2 x 2 factorial, clinical trial, with BP levels measured by blinded observers. Nine academic medical centers recruited 2382 men and women (age range, 30-54 years) not taking antihypertensive drugs, with a diastolic BP of 83 to 89 mm Hg, a systolic BP lower than 140 mm Hg, and a body mass index (the weight in kilograms divided by the square of the height in meters) representing 110% to 165% of desirable body weight. Counseling aimed at helping participants achieve their desirable weight or a 4.5-kg or more weight reduction (in the weight loss and combined groups) and/or sodium intake of 80 mmol/d (in the sodium reduction and combined groups) was provided. RESULTS: From baseline, participants' weight decreased by 4.3 to 4.5 kg at 6 months and by approximately 2 kg at 36 months in the weight loss and combined groups compared with weight changes in the usual care group (all groups, P or = 140 mm Hg systolic or > or = 90 mm Hg diastolic or the use of antihypertensive drugs) was significantly less in each active intervention group than the usual care group (average relative risks, 0.78-0.82). CONCLUSIONS: In overweight adults with high-normal BP, weight loss and reduction in sodium intake, individually and in combination, were effective in lowering systolic and diastolic BP, especially in the short-term (6 months). Although the effects on average BP declined over time, reductions in hypertension incidence were achieved.