Changes in plasma lipoproteins accompanying diet therapy in obese diabetics.

Plasma lipoprotein cholesterol and triglyceride levels were measured in 24 obese not-insulin dependent Pima Indian diabetics and 9 obese nondiabetic controls before and after 1-8 months on a 500 calorie diet. The diabetics were divided into 3 groups--severe, recent onset (n = 10), severe long-term (n = 6), and borderline (n = 8). The diet regimen resulted in weight loss and improved glucose tolerance in all of the diabetics, and insulin secretion increased in the 2 groups of severe diabetics. After the period of weight loss, total plasma cholesterol had declined greater than 20%, and LDL cholesterol decreased 25% in all diabetic groups and in the controls. In all diabetic groups, HDL cholesterol did not decline; therefore the ratio of HDL/LDL cholesterol after diet therapy was significantly increased. In the controls HDL cholesterol declined with weight loss, and the distribution of HDL/LDL cholesterol remained constant. Plasma and VLDL triglyceride levels decreased in all groups in those with initial triglyceride levels greater than 150 mg/dl. The results indicate that weight loss in not-insulin dependent diabetics not only improves glucose tolerance, but also lowers plasma lipids and reverses the dyslipoproteinemia often associated with this disorder. This may influence the risk of arteriosclerotic heart disease in these individuals.