Pharmacological strategies for preventing type 2 diabetes in patients with impaired glucose tolerance.

Type 2 diabetes is an increasingly prevalent disease in the United States, and is associated with microvascular and macrovascular complications. Prediabetes, which is defined as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT), increases the risk of development of type 2 diabetes. Lifestyle improvements, including weight loss and increased physical activity are effective in reducing the conversion of IGT to type 2 diabetes by 58%. However, lifestyle interventions alone may be difficult to maintain. Oral pharmacological agents used to treat type 2 diabetes that improve insulin sensitivity, preserve beta cell function and delay carbohydrate metabolism have been shown to prevent the progression of IGT to type 2 diabetes. The risk reduction of diabetes using metformin, pioglitazone, acarbose, valsartan and orlistat in clinical studies has ranged from 14 to 72%. Therefore, persons with IGT tolerance may benefit from pharmacological therapy to prevent the development of type 2 diabetes.