Effect of sulfonylurea therapy on plasma lipids and high-density lipoprotein composition in non-insulin-dependent diabetes mellitus

To assess the effects of sulfonylurea therapy on plasma lipids and high-density lipoprotein composition, 11 obese diabetic Pima Indians with type II, or non-insulin-dependent, diabetes mellitus were studied before and after tolazamide therapy for one month. Diet composition and weight were kept constant, and the data were compared with a control group of 18 age-, sex-, and weight-matched non-diabetic subjects. Improvement of glycemic control was accompanied by significant decreases in total and very-low-density lipoprotein triglycerides. Total and low-density lipoprotein cholesterol also declined significantly, and there was an increase in the ratio of high-density lipoprotein to low-density lipoprotein cholesterol. Concentrations of total high-density lipoprotein cholesterol, phospholipid, and apolipoprotein A 1 were unchanged. An increase in the proportion of the high-density lipoprotein 2 subfraction, however, was suggested by significant increases in the ratios of high-density lipoportein 2 to high-density lipoprotein 3 cholesterol and apolipoprotein A 1 . There was also a change in the composition of the high-density lipoprotein 2 particle, as indicated by changes in the molar ratio of cholesterol to apolipoprotein A 1 . The data suggest that improvement of glycemic control after sulfonylurea therapy, when weight and diet composition remain constant, reverses several of the lipoprotein abnormalities observed in type II diabetic patients. There was no evidence of changes in lipoproteins in directions associated with an increased risk for atherosclerosis.