Given the long-term health consequences and increasing incidence of
type 2 diabetes, there is great interest to potentially prevent or delay its onset. Primary prevention studies have demonstrated that intensive exercise and
weight reduction, and to a lesser extent certain
antidiabetic agents, can reduce new onset diabetes in at-risk individuals. Results from post hoc analyses and secondary end-point outcomes of large randomized controlled trials of
cardiovascular drugs suggest that these may also have beneficial effects, reducing the incidence of new onset diabetes in addition to their proven cardiovascular benefits. Multiple meta-analyses confirm that drugs primarily acting on the renin-angiotensin system (RAS) reduce the incidence of diabetes in the populations studied, perhaps via improved
insulin sensitivity and/or effects on pancreatic beta cells. However, results from the recent Diabetes REduction Approaches with Medication study specifically failed to show a significant reduction in the incidence of diabetes with
ramipril in individuals with abnormal
glucose tolerance at baseline. There is only limited evidence that
statins improve
glucose tolerance, and although beta-blockers tend to have detrimental effects on
glucose tolerance, newer agents with vasodilatory properties may confer benefits. With current guidelines, the use of
cardiovascular drugs modifying the RAS will increase in at-risk individuals, but at present, they cannot be recommended to prevent diabetes.