What is the role of combination therapy (insulin plus oral medication) in type 2 diabetes?

Abstract

Combination therapy using insulin plus metformin (Glucophage), a sulfonylurea, or both produces glycemic control comparable with using insulin alone, but there is less weight gain when metformin is used (strength of recommendation [SOR]: B, based on systematic review of randomized controlled trials [RCTs] with some heterogeneity). Combination therapy using insulin and pioglitazone (Actos) reduces glycosylated hemoglobin (HbA1c) more than either insulin alone or adding pioglitazone to a sulfonylurea, but results in more weight gain (SOR: A, based on RCT).