The proposed trial will have three phases. Phase I will be directed at identifying an optimal nonpharmacological strategy for reducing blood pressure. Phase II will be aimed at determining the degree to which that optimal strategy can reduce the incidence of new hypertension among persons with high normal blood pressure and/or borderline hypertension. Phase III will involve analysis of results. This application is for Phase I of the trial only. Each of the ten clinical centers will enroll 200 persons and randomly assign them to an untreated control group, or to one of three separate nonpharmacologic treatments for reducing blood pressure. We propose that six individual interventions, and three combined interventions be tested, with each intervention being tested in three different clinics to assure that results can be consistently obtained across sites. Randomized participants will be followed for 36 months, and the blood pressure levels in the various intervention groups will be compared in order to identify the best nonpharmacologic strategy to be used in Phase II. The Center for Health Research (CHR) is prepared to conduct any of the potential nonpharmacologic interventions, and has extensive experience in conducting most of the candidates. We propose that the CHR conduct interventions in 1) combined electrolyte intervention (Na, K, Ca); 2) combined weight loss/fat intake/alcohol reduction/exercise; and 3) relaxation. These are the most complex and difficult of the proposed interventions. The CHR has considerable experience in conducting behavior change studies of diet, exercise, weight loss, and relaxation, and also has broad experience in the conduct of hypertension studies and collaborative clinical trials.
