Effects of Pioglitazone on Visceral Fat Metabolic Activity in Impaired Glucose Tolerance or Type 2 Diabetes Mellitus

Autor: Yoshikazu Nitta, Atsuko Tahara, Yoshihiro Fukumoto, Hayato Kaida, Sho-ichi Yamagishi, Norihiro Kodama, Akihiro Honda, Masatoshi Ishibashi, Minori Mizoguchi, Hisao Ikeda, Jagat Narula, Nobuhiro Tahara, Toshi Abe, Tsutomu Imaizumi
Rok vydání: 2013
Předmět:
Zdroj: The Journal of Clinical Endocrinology & Metabolism. 98:4438-4445
ISSN: 1945-7197
0021-972X
Popis: Excess visceral fat is associated with chronic systemic inflammation and cardiovascular complications. Pioglitazone has been reported to variably influence visceral fat volume; however, its effect on metabolic activity of the visceral fat remains uncharacterized.The aim of this study was to assess the effects of pioglitazone on glucose metabolism of fat tissue by using (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) and computed tomography imaging.FDG-PET and computed tomography imaging were performed in 56 patients with impaired glucose tolerance or type 2 diabetes mellitus; lipid and glycemic profiles and inflammatory biomarkers were obtained in all patients. These patients were randomized to treatment with either pioglitazone or glimepiride for 16 weeks.The metabolic activity of the visceral fat tissues as assessed by FDG uptake was expressed as a target-to-background ratio (TBR) of blood-normalized standardized uptake value.The study was completed in 32 pioglitazone-treated and 21 glimepiride-treated patients (40 men and 13 women; mean age, 67.7 ± 8.1 y; body mass index, 25.0 ± 3.6 kg/m(2); glycated hemoglobin, 6.78 ± 0.70%). Both treatments were well-tolerated and comparably improved glycemic control. At baseline, visceral fat exhibited a higher TBR value than subcutaneous fat (0.55 ± 0.14 vs 0.30 ± 0.07, P.001). Pioglitazone, but not glimepiride, significantly decreased the visceral fat volume (130.5 ± 53.0 to 122.1 ± 51.0 cm(2), P = .013) and TBR values (0.57 ± 0.16 to 0.50 ± 0.11, P = .007). Neither pioglitazone nor glimepiride treatment showed any effect on the volume or TBR values of subcutaneous fat. After 16 weeks of treatment with pioglitazone, reduction in visceral fat TBR was correlated to the increase in high-density lipoprotein cholesterol levels.Our study indicated that pioglitazone decreased the visceral fat volume and its metabolic activity in patients with impaired glucose tolerance or type 2 diabetes mellitus. The beneficial effects of pioglitazone on visceral fat may be independent of its glucose-lowering effect.
Databáze: OpenAIRE