Primary prevention of hypertension represents the best long-term solution to our current epidemic of blood pressure-related cardiovascular disease. Trials of Hypertension Prevention (TOHP) is a three-phase collaborative randomized clinical trial to determine if non-pharmacologic interventions can prevent increases in blood pressure leading to systemic hypertension. Phase I was a 3-year feasibility trial designed to test the short-term effectiveness of seven nonpharmacologic interventions in reducing diastolic blood pressure (DBP). Stress management and dietary sodium reduction were studied at the Newark center, which surpassed its recruitment goals and equalled or exceeded the national performance in achieving intervention and follow-up goals. Phase II will be a 5-year trial to test the effectiveness of the interventions determined to be most effective in Phase I in preventing the onset of definite hypertension. Phase III will be a period for data analysis and reporting of results. Nine of 10 clinical centers and 3 supporting centers participating in Phase I propose to continue in Phase II. Specifically, this phase will test whether the combination of weight loss and dietary sodium restriction or weight loss alone will decrease the incidence of definite hypertension in 2,250 individuals, age 30-54 years, with high normal DBP. In addition, the trial will compare the effects of weight loss and sodium restriction combined and weight loss alone on change in DBP. Recruitment will be divided equally between clinics.. The major eligibility criteria will be DBP (83-89 mmHg) and weight (110-160% of ideal body weight). Follow-up will be for 36-48 months. This proposal describes accomplishments of the Newark center during Phase I and our plans for the planning and implementation of the Phase II protocol. We plan to recruit 250 participants, primarily through mailings to a documented potential population of 500,000. Our large population base, our past experience in non-pharmacologic approaches to hypertension, and our success in Phase I indicate the New Jersey Medical School is likely to be a successful Phase II clinical center.
