Thiazolidinediones and congestive heart failure: a judicious balance of risks and benefits.

Thiazolidinediones are oral antihyperglycemic drugs that have gained significant popularity for use in the treatment of type 2 diabetes mellitus. Their insulin sensitizing effects lead to better glycemic control, in addition to improvements in several cardiovascular parameters independent of blood glucose levels. The pleiotropic effects of thiazolidinediones have led to several cardiovascular outcome studies, many of which have shown promising data, but some of which bring about significant concern. Additionally, the propensity to cause weight gain, fluid retention, peripheral edema, and increased risk of heart failure hospitalizations continue to pose significant challenges for clinicians using these agents in patients with congestive heart failure.