A Cross-Sectional Analysis of NEFA Levels Following a Standard Mixed Meal in a Population of Persons with Newly Diagnosed Type 2 Diabetes Mellitus Across a Spectrum of Glycemic Control.

Non-esterified fatty acids (NEFA) and glucose metabolism are highly linked, but NEFA metabolism in type 2 diabetes mellitus remains controversial. It is generally believed that NEFA levels are augmented in persons with type 2 diabetes mellitus in the face of hyperinsulinemia, and that this augmentation contributes to insulin resistance. Our aim was to investigate NEFA levels following a standard meal tolerance test (MTT) in a population of persons with newly diagnosed type 2 diabetes mellitus (T2DM) across a spectrum of glycemic control. 368 newly diagnosed subjects with T2DM and 70 non-diabetic subjects were fasted overnight and studied for 4 hours aider ingesting a standardised mixed meal (500 kcal: 58% carbohydrate, 22% fat and 19% protein; 75g glucose). Fasting plasma glucose (FPG), fasting plasma insulin (FPI) and fasting plasma NEFA (FPN) were higher in T2DM than in the control group. FPN correlated weakly, but statistically significantly, to FPG (R²=0.150, p<0.0001). Although there was a general trend in the patients with T2DM to have higher FPN levels than healthy subjects (mean FPN: 0.47 mM vs 0.66 mM), but with huge variations as some patients had normal or below normal FPN levels. The variations were not associated with BMI, fasting triglycerides, or FPI. At 60 min after the start of the MTT, NEFA levels were suppressed equally (by 0.3 mM) in both controls and persons with T2DM (mean NEFA: 0.14 mM vs 0.37 mM). Postprandial NEFA suppression was related to the postprandial insulin level and the severity of the disease. Patients with FPG above 13 mM had almost no postprandial suppression of NEFA. In newly diagnosed persons with T2DM NEFA levels are augmented despite fasting hyperinsulinemia, indicating that NEFA metabolism is insulin resistant. Following a mixed meal these subjects were still able to respond to insulin in respect to their NEFA metabolism, but postprandial NEFA levels are highly related to postprandial insulin secretion. [ABSTRACT FROM AUTHOR]