THE EFFECTS OF GLIBENCLAMIDE AND INSULIN ON PLASMA HIGH-DENSITY LIPOPROTEIN IN DIABETICS

Abstract

The effects of various types of treatment such as glibenclamide and insulin on plasma lipids and lipoprotein concentration in diabetics were investigated. Treatment of diabetes mellitus was reevaluated from the standpoint of high density lipoprotein (HDL) metabolism. Diabetic patients (6 men and 15 women) who were admitted in the hospital and kept on a standard diet for diabetes mellitus were studied. Changes of plasma lipoprotein in diabetic patients were followed up before and after treatment with glibenclamide or insulin. Very low density lipoprotein (VLDL) and low density lipoprotein (LDL) were decreased and HDL was increased with insulin treatment. Glibenclamide induced a significant decrease in HDL-cholesterol (Ch). Relationship between triglyceride (TG)-rich lipoproteins and HDL metabolism was studied. A significant negative correlation was found between pretreatment VLDL-TG and changes of VLDL-TG with insulin treatment, indicating an accelerated catabolism of VLDL-TG with possible increase of triglyceride lipases. There was a significant negative correlation between VLDL-TG and HDL-Ch before insulin treatment, but not after treatment. There was no negative correlation between changes of VLDL-TG and changes of HDL-Ch with insulin therapy. An increment of HDL with insulin treatment can not be explained solely by increased HDL formation from TG-rich lipoprotein, and insulin might increase synthesis and secretion of HDL in liver and/or intestine.