Meta-Analysis of Oral Agents for Diabetes Shows Weakness of the Literature

The relation between oral diabetic medications and increased cardiovascular risk has been controversial, with particular concerns raised about rosiglitazone (JW Cardiol Dec 26 2007). Selvin and colleagues undertook a systematic review of this topic and identified 40 randomized trials in the peer-reviewed literature that reported on the cardiovascular risk associated with use of oral therapeutic agents in adults with type 2 diabetes.

Mean patient age in these trials ranged from 52 to 69, and mean baseline hemoglobin A_1c (HbA_1c) level ranged from 6.2% to 10.2%. About two thirds of the trials ran less than 1 year. In trials of metformin versus any comparator, metformin was linked significantly to decreases in cardiovascular mortality (odds rati…