Metformin vs. Pioglitazone as Initial Treatment for Diabetes

Metformin and the thiazolidinediones (e.g., pioglitazone [Actos] and rosiglitazone [Avandia]) are increasingly popular first-line drugs for type 2 diabetes. In this randomized, double-blind multicenter study from Europe, 1199 patients with type 2 diabetes and inadequate responses to diet alone received either metformin (titrated to a maximum of 850 mg 3 times daily) or pioglitazone (titrated to a maximum of 45 mg daily).

Mean hemoglobin A_1c levels decreased almost identically in the two groups: from 8.7% at baseline to about 7.2% at the end of 1 year of treatment. Mean LDL cholesterol levels decreased significantly more with metformin than with pioglitazone; in contrast, mean triglyceride levels decreased, and mean HDL cholesterol levels inc…