EFFECT OF GLIPIZIDE TREATMENT ON POSTPRANDIAL LIPEMIA IN PATIENTS WITH NIDDM

The primary goal of the present study was to examine the effects of improved glycaemic control associated with glipizide treatment on postprandial lipaemia in non-insulin-dependent diabetic patients. The metabolism of triglyceride-rich lipoproteins of intestinal origin was assessed by measuring the retinyl palmitate content in plasma and the Svedberg flotation index (Sf) > 400 and Sf 20-400 lipoprotein fractions. Fasting plasma glucose concentrations (14.5 +/- 0.5 vs 9.0 +/- 0.5 mmol/l), glycated haemoglobin levels (13.1 +/- 0.6 vs 9.7 +/- 0.6 %), and daylong plasma glucose concentrations were all significantly lower after glipizide treatment (p < 0.001). The improvement in glycaemic control was associated with increases in insulin-mediated glucose uptake (p < 0.001) and plasma post-heparin lipoprotein and hepatic lipolytic activities (p<0.02). Both fasting plasma triglyceride (3.09 +/- 0.51 vs 2.37 +/- 0.34 mmol/l), and postprandial triglyceride concentrations (p < 0.05-0.001) were lower following glipizide treatment, associated with a significant fall in retinyl palmitate content in all three lipoprotein fractions (p < 0.02-0.001), with the most substantial decrease seen in the Sf 20-400 fraction. These data indicate that glipizide-induced improvement in glycaemic control was associated with changes in the metabolism of triglyceride-rich lipoproteins of intestinal origin that would be anticipated to reduce risk of coronary heart disease in non-insulin-dependent diabetic patients.