Sibutramine effect on metabolic control of obese patients with type 2 diabetes mellitus treated with pioglitazone

Thiazolidinediones are supposed to be the pharmacologic agents that more physiologically fight the insulin resistance, but a possible adverse effect may be a weight increase. The aim of the study was to test the efficacy and tolerability of sibutramine on the metabolic effect of pioglitazone in obese patients with type 2 diabetes mellitus. All enrolled patients were required to have been diagnosed as being diabetic for at least 6 months and did not have glycemic control with diet and oral hypoglycemic agents such as sulfonylureas or metformin, both to the maximum tolerated dose. After a run-in period in which the eligible patients took a fixed dose of pioglitazone (30 mg/d), the patients were randomized to receive also sibutramine (10 mg/d) or placebo for 6 months. We assessed body mass index, hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), postprandial plasma insulin (PPI), lipid profile, lipoprotein parameters, and lipoprotein (a) at baseline and after 3 and 6 months. No body mass index change was observed after 3 and 6 months in the pioglitazone + placebo (pp) group. Significant decrease was present in the pioglitazone + sibutramine (ps) group after 3 (P < .05) and 6 months (P < .01) compared with the baseline values, and this variation was significant (P < .05) between groups. A significant HbA1c decrease was observed after 3 (P < .05) and 6 months (P < .01) in both groups with respect to the baseline values. There was no difference in HbA1c value between the 2 groups. No FPG, PPG, FPI, PPI, and homeostasis model assessment index change was observed at 3 months, whereas a significant decrease was present after 6 months (P < .05), in both groups with respect to the baseline values. There was no difference in FPG, PPG, FPI, PPI, and homeostasis model assessment index value between the pp and ps groups. No significant low-density lipoprotein cholesterol change was observed at 3 months, whereas a significant decrease was present after 6 months (P < .05), in both groups with respect to the baseline values. There was no difference in low-density lipoprotein cholesterol value between the pp and ps groups. No triglyceride variation was present at 3 and 6 months in the pp group and at 3 months in the ps group, whereas a significant decrease was observed at 6 months (P < .05) in the ps group with respect to the baseline values. There was no difference in triglyceride value between both groups. No high-density lipoprotein cholesterol, apolipoprotein A-I, apolipoprotein B, and lipoprotein (a) changes were present in both groups with respect to the baseline values. Sibutramine appears to be a tolerable and efficacious drug when added to pioglitazone for the global management of obese diabetic patients.