Role of renin-angiotensin system blockade in patients with diabetes mellitus.

The investigators review the evidence of the potential role of renin-angiotensin system (RAS) blockers in delaying or preventing the onset and progression of diabetes mellitus (DM) and cardiovascular disease and the suggested mechanisms by which these agents exert their favorable metabolic and cardiovascular effects. Data from clinical trials suggest that RAS blockade not only reduces cardiovascular risk in patients with DM but also may prevent or delay DM onset in at-risk subjects. These observations set the stage for further studies evaluating the risk for developing DM as a primary end point: the Diabetes Reduction Approaches With Ramipril And Rosiglitazone Medications (DREAM) trial, in which ramipril significantly increased regression to normoglycemia (although it did not reduce the primary end point of new-onset DM or death), and the ongoing Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial, the only DM prevention trial also powered to evaluate whether a reduced risk for DM is associated with a reduction in cardiovascular disease events. In conclusion, overwhelming evidence suggests that the RAS plays an important role in the pathogenesis of DM and its associated cardiovascular risks.