Pharmacologic prevention or delay of type 2 diabetes mellitus

OBJECTIVE: To evaluate the current data on pharmacologic interventions intended to prevent or delay the onset of type 2 diabetes mellitus. DATA SOURCES: Searches of MEDLINE (1966-July 2002) and an extensive manual review of journals were performed using the key search terms diabetes mellitus, metformin, acarbose, troglitazone, orlistat, nateglinide, risk reduction, and prevention. STUDY SELECTION AND DATA EXTRACTION: All articles identified from the data sources were evaluated, and all information deemed relevant was included for this review. Randomized controlled trials and meta-analyses were included if the primary outcome measure was prevention of diabetes and/or change in the rate of progression to diabetes. DATA SYNTHESIS: Type 2 diabetes mellitus is a growing epidemic. Major risk factors include obesity, impaired glucose tolerance, and impaired fasting glucose. Complications of diabetes result in significant morbidity and mortality and are a substantial public health issue. Four randomized, blinded, controlled trials have assessed the efficacy of different medications, including metformin, troglitazone, acarbose, and orlistat, at decreasing the risk of progression to diabetes in patients at risk for developing diabetes. All of these agents decreased the risk of progression to diabetes. CONCLUSIONS: Metformin, troglitazone, acarbose, and orlistat have been shown to decrease the risk of progression to diabetes in patients at risk for developing diabetes. Other questions that address issues such as identifying target populations, cost-effectiveness, and screening strategies must be answered to more fully define the place of pharmacologic therapy to prevent or delay diabetes.