Abstract 11771: Effects of Pioglitazone on Coronary Arterial Inflammation Evaluated by Serial FDG-PET/CT in Patients with Impaired Glucose Tolerant or Type 2 Diabetes

Abstract

OBJECTIVE_Measurements of 18F-fluorodeoxyglucose (FDG) uptake as a potential marker of inflammatory activity of the vessel wall could be useful to identify vulnerable atherosclerotic plaques. The aim of this study was to compare the effect of pioglitazone, an insulin sensitizer, with glimepiride, an insulin secretagogue, on coronary arterial inflammation with serial FDG-positron emission tomography (PET) imaging. Methods_Fifty-five atherosclerotic patients with impaired glucose tolerant (IGT) or type 2 diabetes mellitus (DM) underwent determinations of blood chemistries, anthropometric variables and FDG-PET/CT. We could not measure the FDG activity in the coronary artery in 8 patients because of intense myocardial FDG uptake. The remaining patients were randomized to receive either pioglitazone (n=25) or glimepiride (n=22) for 12 weeks. Effects of the drugs on coronary arterial inflammation (left main coronary trunk: LMT) were evaluated by FDG-PET/CT at study completion. LMT inflammation was measured by blood-normalized standardized uptake value, known as a target-to-background ratio (TBR). Results_After 12-week treatment, fasting plasma glucose and HbA1c values were comparably reduced in the two groups. TBR values were significantly decreased in the pioglitazone group (1.39±0.32 to 1.27±0.27, P<0.05), but was substantially increased in the glimepiride group (1.45±0.29 to 1.54±0.35, N.S.). HsCRP change from baseline was significantly greater in the pioglitazone group than in the glimepiride group (P<0.04). Conclusions_Our study suggests that pioglitazone could attenuate coronary arterial inflammation in IGT or DM patients in a glucose-lowering independent manner. Pioglitazone may be a promising strategy for the treatment of coronary vulnerable plaques in IGT or DM patients.