The Trial of Antihypertensive Interventions and Management (TAIM) study. Adequate weight loss, alone and combined with drug therapy in the treatment of mild hypertension.

This report examines the effect of weight loss, alone and in combination with drugs, on diastolic blood pressure change in the Trial of Antihypertensive Interventions and Management (TAIM), which is a randomized, multicenter, placebo-controlled clinical trial of drug and diet combinations in the treatment of mild hypertension among 787 patients. Diastolic blood pressure drop (11.6 mm Hg) at 6 months among those patients who were randomized to weight reduction and placebo drug treatment was greater among those who lost 4.5 kg or more, than the 7-mm Hg drop for those who lost less than 2.25 kg or for the placebo-treated control group, and it was statistically equivalent to the reduction achieved by 25 mg of chlorthalidone or 50 mg of atenolol (11.1- and 12.4-mm Hg drop, respectively). Weight loss potentiated effects of drugs, with reductions of 18.4 mm Hg, for those patients who were taking atenolol and had a 4.5-kg or more weight loss, and of 15.4 mm Hg, for those patients who were taking chlorthalidone and had at least a 2.25-kg weight loss. We concluded that effective weight loss (greater than or equal to 4.5 kg) lowers blood pressure similarly to low-dose drug therapy and potentiates drug effects, with the apparent 4.5-kg threshold being lowered to 2.25 kg for those patients who receive chlorthalidone.