Metabolic response to oral lipid overload in diabetes and impaired glucose tolerance

Post-prandial hyperglycemia and hypertriglyceridemia have been related to atherogenesis. The aim of this study was to evaluate the response of plasma lipoproteins to a lipid overload in subjects with diabetes (DM), impaired glucose tolerance (IGT) and normals (N). Seventy-seven subjects were selected, 36-85 years, plasma glucose (G) < 140 mg/dl and triglycerides (TG) < 150 mg/dl; those without diabetes underwent a glucose tolerance test (GTT), which classified them into three groups: N, 2 h G < 140 mg/dl, n = 37; IGT, 2 h G 140-200 mg/dl, n = 20; and DM, previous diabetes or 2 h G > 200 mg/dl, n = 20. They were submitted to a clinical evaluation and an oral lipid overload (1000 kcal, 58% fat). Fasting, 4 and 6-h blood samples after the meal were collected for G, insulinaemia (1), TG, cholesterol and their fractions, and HOMA-IR. Fasting and post-lipid overload lipoproteins were similar between groups, but 6 h TG was still high in DM versus IGT and N as compared to their 4 h values. There was a positive correlation between fasting TG versus 6 h TG (r = 0.78, p < 0.001). We conclude that individuals with impaired glucose tolerance and with diabetes mellitus have a slower plasma reduction of triglycerides after lipid overload, as well as an altered glucose and post-prandial insulin response. (c) 2004 Elsevier Ireland Ltd. All rights reserved.