Efficacy and safety of rosiglitazone plus metformin in Mexicans with type 2 diabetes

Background Type 2 diabetes is a growing problem in Mexico. The present study was undertaken to evaluate the efficacy and safety of rosiglitazone 2 mg or 4 mg twice daily (bd) in combination with metformin 2.5 g/day in Mexican patients whose type 2 diabetes was inadequately controlled with metformin alone. Methods This randomized, double-blind, placebo-controlled study was conducted at four centers in Mexico. A total of 116 patients were randomized to metformin 2.5 g/day plus placebo (n = 39), metformin 2.5 g/day plus rosiglitazone 2 mg bd (n = 3 7), or metformin 2.5 g/day plus rosiglitazone 4 mg bd (n = 40) for 26 weeks. Results Mean hemoglobin A(1c) (HbA(1c)) levels decreased significantly from baseline to Week 26 in the rosiglitazone 2 mg bd (-0.7%; p = 0.0052) and 4 mg bd (-1.2%; p = 0.0008) groups, but increased in the placebo group (+0.3%; P=0.2651). Mean fasting plasma glucose and fructosamine levels also improved significantly with metformin plus rosiglitazone therapy in a dose-ordered manner compared with placebo (p less than or equal to 0.0019 and p = 0.0006, respectively). C-peptide and immunoreactive insulin levels were decreased from baseline in both rosiglitazone groups. Although mean increases in total cholesterol, low-density lipoprotein (LDL) -cholesterol, and high-density lipoprotein (HDL)-cholesterol were observed in the rosiglitazone groups, the total cholesterol: HDL-cholesterol ratio remained unchanged. The proportion of patients with one or more adverse events was similar across all three groups. There were no cases of hepatotoxicity. Conclusion Addition of rosiglitazone 2 mg bd and 4 mg bd to metformin therapy improved glycemic control in Mexican patients whose type 2 diabetes was inadequately controlled by metformin alone. Furthermore, the combination of rosiglitazone plus metformin was well tolerated. Copyright (C) 2002 John Wiley Sons, Ltd.