DIETARY SUBSTITUTION OF MEDIUM-CHAIN TRIGLYCERIDES IN SUBJECTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS IN AN AMBULATORY SETTING - IMPACT ON GLYCEMIC CONTROL AND INSULIN-MEDIATED GLUCOSE-METABOLISM

Objective: We have previously shown in an acute inpatient setting that dietary substitution of 77.5% of fat kcal as medium chain triglycerid es (MCT) increased insulin-mediated glucose metabolism in patients wit h non-insulin-dependent diabetes mellitus (NIDDM), and that this effec t appeared to be mediated by increases in insulin-mediated glucose dis posal. The purpose of this study was to test the application of dietar y substitution of medium chain triglycerides as an adjunctive tool in ambulatory therapy of NIDDM. Methods: Five subjects with NIDDM underwe nt a baseline 6 hour insulin/glucose euglycemic clamp study, with simu ltaneous H-3-glucose infusion for calculation of glucose disposal rate and hepatic glucose output. Subjects were then randomized to begin on e of two 30-day experimental diets, with long chain (LCT) or medium ch ain triglycerides (MCT), and subsequent crossover to the other diet. A 6 hour euglycemic clamp was repeated after each diet phase. Results: Diet records and urinary organic acid excretion indicated a high level of dietary compliance by the study participants. Postprandial blood g lucose excursions were less after one month on the diet with MCT than after the LCT diet (p = 0.004). However, fasting serum glucose, serum fructosamine (a measure of glycemia), fasting insulin, hepatic glucose output, and insulin-mediated glucose metabolism were not improved by the dietary substitution of MCT. Conclusion: These data indicate that supplementation of a tolerable amount of MCT in a conventional diabeti c exchange diet has little impact on glycemic control in subjects with NIDDM in an ambulatory setting.