Obesity and hypertension. Demonstration of a "floor effect".

Weight loss has a role in the treatment of essential hypertension. With the use of a medically supervised protein-sparing supplemented fast and a behavioral program, the changes in blood pressure as a result of weight loss in 135 obese hypertensive subjects were examined. Subjects' weight, blood pressure, and antihypertensive medication intake were recorded at baseline, at conclusion of supplemented fast, and at follow-up. Significant weight loss accompanied by decrements in blood pressure occurred in all subjects. Reductions in the number of antihypertensive medications also occurred. Although the correlations between changes in weight and blood pressure were significant, their moderate size suggests the amount of weight loss accounted for a relatively small part of the blood pressure reduction. Given the large weight losses in the majority of subjects, there appears to be a degree of weight loss beyond which further decrements in blood pressure will not occur ("floor effect"). Maintenance of blood pressure reductions at realimentation/follow-up suggests that weight loss, and not the supplemented fast, results in decreased blood pressure and medication level.