Abstract 11735: Effects of Pioglitazone versus Glimepiride on Abdominal Fat Glucose Metabolism in Patients with Impaired Glucose Tolerance and/or Type 2 Diabetes Mellitus

Abstract

OBJECTIVE Visceral fat is associated with cardiovascular morbidity and mortality. It was reported that pioglitazone decreased, increased, or unchanged visceral fat volume. It is unknown that pioglitazone has any effects of fat glucose metabolism of visceral fat. Accordingly, we examined effects of pioglitazone on the volume and glucose metabolism of visceral fat by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) scans in patients with impaired glucose tolerance (IGT) and/or type 2 diabetes mellitus (T2DM).

Methods_ Fifty-four patients with IGT and/or type 2 diabetes mellitus (T2DM) underwent FDG-PET/CT with determinations of blood chemistries, anthropometric variables. They were randomized to receive either pioglitazone (n=32) or glimepiride (n=22) for 12 weeks. FDG uptake in the adipose tissue was expressed as a target-to-background ratio (TBR) of blood-normalized standardized uptake value.

Results At baseline visceral fat exhibited higher FDG uptake than subcutaneous fat (p<0.01). Both treatments comparably decreased fasting plasma glucose, HbA1c and subcutaneous FDG uptake. For the visceral fat, pioglitazone significantly decreased FDG uptake (0.57±0.16 to 0.50±0.11, P<0.01), but glimepiride did not (0.54±0.11 to 0.57±0.11, P=0.46). The decrease in the FDG uptake in the visceral fat was significantly correlated with the HDL-cholesterol elevation (P<0.01) after pioglitazone treatments. Only pioglitazone decreased visceral fat volume from 130.6±53.0 to 122.1±50.9 cm²(p<0.02).

Conclusions Our study indicated that pioglitazone decreased FDG uptake and volume of the visceral fat in patients with IGT and/or T2DM patients. These effects of pioglitazone may be ascribed to beyond-glucose lowering-effects.