Effect of dietary change on the return of hypertension after withdrawal of prolonged antihypertensive therapy (DISH). Dietary Intervention Study of Hypertension.

The possibility exists that dietary modification may increase the number of patients who remain normotensive after drug withdrawal. In an effort to resolve this question, former Hypertension Detection and Follow-up Program Stepped Care participants (n = 496) were randomized into four major groups at the end of the programme (greater than 5 years antihypertensive therapy): controls (continue medication); discontinue medication, no dietary intervention; discontinue medication and weight loss; discontinue medication and reduce sodium. Groups 1, 2 and 4 were further divided into obese (greater than or equal to 120% ideal weight, and non-obese groups). The weight reduction group (greater than or equal to 120% ideal weight) lost 10.1 +/- 11 lbs without changing dietary sodium (n = 87). The sodium restriction group reduced urine sodium excretion from 145 to 97 mEq per day (n = 169). Sixty per cent of the weight loss group were normotensive at 56 weeks compared to 35% withdrawn from medication without dietary intervention. The highest 56 weeks success rates were in the mild non-overweight hypertensives on sodium restriction (78%), and the mild overweight hypertensives on weight reduction (72%). Randomization to either weight loss group or sodium restriction group increased the likelihood of remaining off drugs (adjusted odds ratio of 3.43 for the weight group and 2.17 for the sodium group (P less than 0.05). Age, severe hypertension greater than 5 years previous to entry into Dietary Intervention Study of Hypertension (DISH) or need for several drugs increased the chance of failure.