Current Issues: Use of Thiazolidinediones in Type 2 Diabetes

Advantages:
David M Kendall, MD

Cautions in therapeutic use:
Philip Home, DPhil, MA, DM, FRCP

Reviewed by Joelle Escoffery, PhD

Use of thiazolidinediones (TZDs) in the treatment of type 2 diabetes was debated.  Evidence supporting TZD use included glycemic control comparable to other treatments for type 2 diabetes, the potential role of TZDs in diabetes prevention, the ability to treat insulin resistance and cardiovascular risk, and improved tolerability over other available agents for the treatment of type 2 diabetes.  Specifically noteworthy was the evidence from the Diabetes Prevention Program, which showed a 75% reduction in type 2 diabetes with troglitazone in the short term (no longer available due to hepatotoxicity), as well as a 25% reduction in type 2 diabetes after three years without the drug, suggesting the possibility that TZDs may preserve β-cell function to some degree. Beneficial effects of TZD use on lipid profile were also noted.

Therapeutic cautions of TZD use included the preliminary nature of much of the research on TZD efficacy (specifically, no hard cardiovascular outcomes), results from the UKPDS suggesting that there is no reason to believe that any available agent prevents β-cells from declining, safety concerns, and cost-effectiveness concerns.  Specifically, early insulin therapy for patients with type 2 diabetes was presented as a suitable alternative, as it is more cost-effective and proven to be efficacious. Concerns about edema, anemia, and congestive heart failure with TZD use were also noted.