Glitazones and congestive heart failure: update on PROactive, ADOPT, DREAM and RECORD clinical trials

Thiazolidinediones (TZDs) are used as insulin sensitizers in the treatment of type 2 diabetes, but are associated with an increased risk of congestive heart failure (CHF). The odds ratio of ICC was 1.43 (pioglitazone vs placebo) in diabetic patients with high cardiovascular risk in the PROactive trial while it averaged 1.22 (rosiglitazone vs metformin) and 2.20 (rosiglitazone vs metformin) in the ADOPT study. In the interim analysis of the ongoing RECORD trial, the odds ratio averaged 2.15 (rosiglitazone vs metformin or sulfonylureas). In four real life registries, the relative risk of CHF with TZDs varied between 1.06 and 1.76 (between 1.10 and 1.44 combined with insulin) as compared to a treatment without TZDs. Such higher CHF risk should be appreciated according to the potential benefits of glitazones in the management of type 2 diabetes.