Effect of metformin plus roziglitazone compared with metformin alone on glycaemic control in well-controlled Type 2 diabetes

Aims To investigate the effect of metformin plus roziglitazione (RSGMET) compared with metformin alone (MET) on glycaemic control in well‐controlled Type 2 diabetes. Methods Subjects (drug naïve or those on glucose‐lowering monotherapy) were randomized (n = 526), following a 4‐week placebo run‐in period, to RSGMET [4 mg rosiglitazone (RSG)/500 mg MET] or MET 500 mg. From weeks 2–18, medication was escalated every 4 weeks (based on gastrointestinal tolerability), then remained at RSGMET 8 mg/2 g or MET 3 g for 14 weeks. Results RSGMET reduced HbA1c from 7.2 ± 0.6 to 6.7 ± 0.8% at week 32, compared with a reduction from 7.2 ± 0.6 to 6.8 ± 0.9% with MET (treatment difference −0.13%; P = 0.0357). More subjects achieved an HbA1c value of ≤ 6.5% at week 32 with RSGMET (51.6 vs. 43.7%), but the treatment difference was not significant (odds ratio 1.37, P = 0.0949). RSGMET produced larger reductions from baseline in mean fasting plasma glucose (adjusted difference −0.62 mmol/l, P