Management of type 2 diabetes in patients with heart failure.

Diabetes mellitus and heart failure (HF) commonly coexist, and together these conditions are associated with increased morbidity and mortality compared with either condition alone. Although the optimal treatment strategy to achieve glucose control in HF patients with type 2 diabetes has not been well studied, given the common coexistence of these conditions and the need to adequately treat hyperglycemia to prevent microvascular complications, it is important for clinicians to understand the potential implications of diabetic therapy in patients with established HF. Until recently, metformin was contraindicated in patients with HF because of the potential risk of lactic acidosis; however, recent retrospective studies of metformin use in HF patients have shown that this medication may be used safely and indeed may be beneficial in patients with stable HF. The association between thiazolidinediones (TZDs) and HF remains controversial, but recent prospective randomized trials of TZD use in HF patients suggest that worsening volume retention associated with these agents may lead to worsening of HF symptoms. The recently developed incretin-based therapies, such as exenatide and sitagliptin, also have not been extensively studied in HF populations; however, small pilot studies of glucagon-like peptide-1 have shown potential promise in the treatment of diabetic patients with HF. Although they may be difficult to perform, future randomized controlled trials are needed to establish optimal treatment goals and strategies in this population.