Effect of a low fat diet on carbohydrate metabolism in patients with hypertension.

Plasma glucose and insulin responses to both a 75-g oral glucose challenge and to conventional meals were determined in eight patients with hypertension and compared with values of a control population. The results indicated that patients with hypertension had significantly higher than normal plasma glucose and insulin concentrations in both situations. Furthermore, when dietary carbohydrate was increased by 16% of total calories (with a reciprocal reduction in dietary fat), the hyperglycemia and hyperinsulinemia present in patients with hypertension were accentuated. Since low fat-high carbohydrate diets are usually recommended for patients with hypertension, these data suggest that abnormalities of glucose and insulin metabolism associated with hypertension would be increased if patients with high blood pressure followed conventional dietary advice. Since hyperglycemia and hyperinsulinemia have been shown to be associated with an increased risk of developing coronary artery disease, it may be appropriate to reevaluate the clinical utility of low fat-high carbohydrate diets in the treatment of hypertension.