Effects of pioglitazone on metabolic parameters, body fat distribution, and serum adiponectin levels in Japanese male patients with type 2 diabetes

The aim of this study was to evaluate the effects of pioglitazone on clinical and metabolic parameters, body fat distribution, and serum adiponectin, a recently discovered antiatherosclerotic hormone, in Japanese patients with type 2 diabetes. Ten male patients aged 40 to 66 (57.7 [plusmn] 7.4) years, who were being treated with dietary therapy alone (n = 7) or with a stable dose of sulfonylurea (n = 3), were studied at baseline and after 3 months of pioglitazone treatment (30 mg/d). Body mass index (BMI), blood pressure, fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), serum insulin, adiponectin, and lipid profile were measured. Also, visceral adipose tissue area (VAT) and subcutaneous adipose tissue area (SAT) at the umbilical level were determined by computed tomographic (CT) scanning. Mean blood pressure (109 [plusmn] 14 to 101 [plusmn] 10 mm Hg), FPG (8.6 [plusmn] 1.4 to 7.0 [plusmn] 1.0 mmol/L), serum insulin (54 [plusmn] 11 to 30 [plusmn] 8 pmol/L, P [lt ] .01 for all), and HbA1c (6.7 [plusmn] 0.8 to 6.1% [plusmn] 0.6%, P = .013) decreased significantly during 3 months of pioglitazone treatment. BMI (26.4 [plusmn] 3.2 to 27.0 [plusmn] 3.5 kg/m2), low-density lipoprotein (LDL) cholesterol (124 [plusmn] 24 to 138 [plusmn] 24 mg/dL) and SAT (155 [plusmn] 69 to 179 [plusmn] 81cm2, P [lt ] .05 for all) increased, while triglycerides and high-density lipoprotein (HDL) cholesterol did not change significantly after 3 months of pioglitazone treatment. Serum adiponectin level increased in all patients (4.8 [plusmn] 1.7 to 14.4 [plusmn] 2.1 [mu ]g/mL, P = .005). VAT tended to increase (165 [plusmn] 38 to 180 [plusmn] 46 cm2) and VAT/SAT ratio tended to decrease (1.2 [plusmn] 0.3 to 1.1 [plusmn] 0.3), but these differences did not reach statistical significance. These results suggest that pioglitazone exerts good glycemic and blood pressure control despite increased BMI and SAT in Japanese male patients with type 2 diabetes. It is also suggested that pioglitazone may have an antiatherosclerotic effect by increasing serum adiponectin level.