What is the best strategy for impaired glucose tolerance in nonpregnant adults?(CLINICAL INQUIRIES)

* Evidence Summary

Both IGT and IFC are associated with a significant risk of developing diabetes and its associated cardiovascular comorbidities; thus, the primary goal for treatment is to prevent or delay the onset of diabetes. Recent well-designed studies have demonstrated benefits of lifestyle interventions for patients with IGT.

In the US Diabetes Prevention Program (DPP), 3234 patients with IGT and a body-mass index (BMI) of at least 24 kg/[m.sup.2] were randomly assigned to one of the following groups: placebo, metformin, or intensive lifestyle modification. After an average follow-up of 2.8 years, there was a 14% absolute risk reduction in the progression to diabetes in the lifestyle intervention group compared with placebo (number needed to treat [NNT]=7). (1) In the Finnish Diabetes Prevention Study, the lifestyle intervention group had a 12.5% absolute risk reduction compared with the control group (NNT=8). (2) Successful lifestyle interventions in these studies included weight loss of 5% to 7%, decreased fat intake, increased fiber intake, and 150 minutes of exercise per week. (1-2)

Drug therapy with metformin, acarbose, and troglitazone has also been successful in preventing or …