PURPOSE: Stress Management Intervention (SMI) was one of seven nonpharmacologic approaches evaluated in Phase I Trials of Hypertension Prevention (TOHP-I) for efficacy in lowering diastolic blood pressure (BP) in healthy men and women aged 30 to 54 years with diastolic BP 80-89 mm Hg.METHODS: A total of 242 and 320 participants were randomized to SMI or an assessment only" SMI Control, respectively, at four clinical centers. The SMI consisted of 37 contact hours in 21 group and two individual meetings over 18 months and included: training in four relaxation methods, techniques to reduce stress reactions, cognitive approaches, communication skills, time management, and anger management within a general problem-solving format. Standardized protocols detailed methods and timing for collecting BP, psychosocial measures, and urinary samples from both SMI and SMI Control participants.RESULTS: In intention-to-treat analyses, although significant baseline to termination BP reductions were observed in both groups, net differences between the SMI and SMI Control groups' BP changes (mean (95% CI)) were not significant: -0.82 (-1.86, 0.22) for diastolic BP, and -0.41 (-1.96, 1.01) for systolic BP. Extensive adherence sub-group analyses found one effect: a significant 1.36 mm Hg (p = 0.01) reduction in diastolic BP relative to SMI Controls at the end of the trial for SMI participants who completed 61% or more of intervention sessions.CONCLUSIONS: While the TOHP-I SMI was acceptable to participants as evident from high levels of session completion, the absence of demonstrated BP lowering efficacy in intention-to-treat analyses suggests that the TOHP-I SMI is an unlikely candidate for primary prevention of hypertension in a general population sample similar to study participants. The isolated finding of significant diastolic BP lowering in SMI participants with higher adherence provides very weak evidence of SMI BP lowering efficacy and may be a chance finding. Whether similar or other stress management interventions can produce significant BP lowering in populations selected for higher levels of BP, stress, or intervention adherence remains to be demonstrated. Ann Epidemiol 2000;10:45-58. Published by Elsevier Science Inc.

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, 2x2 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<.001). Sodium excretion decreased 50 and 40 mmol/d at 6 and 36 months, respectively, in the sodium reduction group and about 15 mmol/d less at each time point in the combined group compared with the usual care group (all groups, P<.01). Compared with the usual care group, BP decreased 3.7/2.7 mm Hg in the weight loss group, 2.9/1.6 mm Hg in the sodium reduction group, and 4.0/2.8 mm Hg in the combined group at 6 months (all groups, P<.001). At 36 months, BP decreases remained greater in the active intervention groups than in the usual care group (weight loss group, 1.3/0.9 mm Hg; sodium reduction group, 1.2/0.7 mm Hg; combined group, 1.1/0.6 mm Hg). Differences were statistically significant for systolic and diastolic BP in the weight loss group and for systolic BP in the sodium reduction group. Through 48 months, the incidence of hypertension (BP greater than or equal to 140 mm Hg systolic or greater than or equal to 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.

Objective.-To test the short-term feasibility and efficacy of seven nonpharmacologic interventions in persons with high normal diastolic blood pressure.Design.-Randomized control multicenter trials.Setting.-Volunteers recruited from the community, treated and followed up at special clinics.Participants.-Of 16 821 screenees, 2182 men and women, aged 30 through 54 years, with diastolic blood pressure from 80 through 89 mm Hg were selected. Of these, 50 did not return for follow-up blood pressure measurements.Interventions.-Three life-style change groups (weight reduction, sodium reduction, and stress management) were each compared with unmasked nonintervention controls over 18 months. Four nutritional supplement groups (calcium, magnesium, potassium, and fish oil) were each compared singly, in double-blind fashion, with placebo controls over 6 months.Main Outcome Measures.-Primary: change in diastolic blood pressure from baseline to final follow-up, measured by blinded observers. Secondary: changes in systolic blood pressure and intervention compliance measures.Results.-Weight reduction intervention produced weight loss of 3.9 kg (P < .01), diastolic blood pressure change of - 2.3 mm Hg (P < .01), and systolic blood pressure change of -2.9 mmHg (P < .01). Sodium reduction interventions lowered urinary sodium excretion by 44 mmol/24 h (P < .01), diastolic blood pressure by 0.9 mm Hg (P < .05), and systolic blood pressure by 1.7 mm Hg (P < .01). Despite good compliance, neither stress management nor nutritional supplements reduced diastolic blood pressure or systolic blood pressure significantly (P > .05).Conclusions.-Weight reduction is the most effective of the strategies tested for reducing blood pressure in normotensive persons. Sodium reduction is also effective. The long-term effects of weight reduction and sodium reduction, alone and in combination, require further evaluation.