Obese type 2 diabetic subjects are recently increasing in Korea, indicating the importance of insulin resistance rather than insulin secretory defects in the pathophysioloy of type 2 diabetes. The purpose of this study is to evaluate the safety and efficacy of fixed dose rosiglitazone/metformin combination therapy in poorly controlled subjects with type 2 diabetes mellitus.

12 type 2 diabetic subjects who had a HbA1c > 11% or fasting plasma glucose > 15 mmol/L were included. After a 2 week screening period, the subjected took the fixed does rosiglitazone/metformin for 24 weeks. The treatment with rosiglitazone/metformin began at week 0 with an initial dose of 4 mg/1000 mg and, unless tolerability issues arose, subjects would be increased to 6 mg/1500 mg at week 4 and at week 8 to the maximum dose of 8 mg/2000 mg. The primary object of this study was to characterize the magnitude of HbA1c reduction from baseline after 24 weeks of rosiglitazone and metformin treatment in poorly controlled type 2 diabetics.

The mean age of the subjects was 48.9 ± 10.6 years old, body mass index was 25.0 ± 3.5 kg/m², HbA1c was 12.0 ± 1.0%, and fasting plasma glucose was 16.3 ± 3.1 mmol/L. HbA1c was reduced to 7.54 ± 1.45% and fasting plasma glucose reduced to 7.96 ± 2.38 mmol/L at week 24. The proportion of HbA1c responder who showed the reduction from baseline of ≥ 0.7% or HbA1c < 7% was 11 among 12 subjects (91.7%). 41% of the subjects (5 among 12 subjects) achieved HbA1c level < 7.0% and 75% (9 among 12 subjects) achieved HbA1c level < 8.0%.

In this study, rosiglitazone and metformin combination therapy was effective in glycemic control in poorly controlled subjects with type 2 diabetes mellitus.