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

Abstract

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=37), 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<or=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.