Primary prevention of hypertension--a randomized controlled trial.

Nutritional-hygienic intervention is a key strategy in the control of hypertension through primary prevention. To test the efficacy of this approach, 201 men and women were selected to participate in a randomized controlled trial on the primary prevention of hypertension. Individuals were taken into the trial if their diastolic blood pressure at entry was 80-89 mm Hg with either relative weight 1.10-1.49 or heart rate of 80 or greater. Half of the eligible persons were randomized into the monitored group and half were randomized into the intervention group receiving individual intervention to achieve a weight loss of 10 or more lbs (greater than or equal to 4.5 kg), to reduce Na intake to 75 mmol (1800 mg), to limit alcohol intake to no more than 2 drinks per day (26 g) and to engage in regular moderate physical activity. At two years, the 75 participants of the intervention group showed a mean weight loss of 5.2 lbs. among those initially overweight, a mean reduction in Na intake of 44% of goal and a moderate reduction of alcohol intake. Self-reported exercise had also increased and was reflected in the larger decrease in mean heart rate compared with the monitored group. Diastolic blood pressure was only slightly lower among the intervention group compared to the monitored group, but was an additional 4.0 mm Hg lower among those intervention participants achieving weight loss and reduction in Na intake greater than the median for the group. In addition, at two years, a rise in diastolic blood pressure sufficient to require antihypertensive medication occurred in 5 participants of the control group compared to 0 of the intervention group. At three years, 11 monitored and 3 intervention group participants required antihypertensive medication.