Comparing Medications for Type 2 Diabetes: What's Known

Charles P. Vega, MD


August 30, 2011

In This Article

Best Evidence Review September 2011

This major review compares efficacy and safety of medications for type 2 diabetes.


Type 2 diabetes is a problem on the rise in the United States, and new treatment options have emerged to improve glycemic control in patients. However, how do these new treatment options compare with established therapy in terms of efficacy and safety? A recent review funded by the Agency for Healthcare Research and Quality should help physicians to make better informed choices in prescribing drugs to treat type 2 diabetes.

Best Evidence Reference:

Bennett WL, Maruthur NM, Singh S, et al. Comparative effectiveness and safety of medications for type 2 diabetes: an update including new drugs and 2-drug combinations. Ann Int Med. 2011;154:602-613.


Diabetes can be considered an epidemic in the United States. Approximately 8% of Americans have diabetes, although as many as one quarter of these remains undiagnosed.[1] The prevalence of diabetes has approximately doubled in the last 2 decades, and if current trends continue, 1 in 3 children born now will develop the condition. Ethnic minorities experience a disproportionate burden of diabetes, with the prevalence among black, Hispanic, and American Indian women approximately 2-4 times that of white women.

The cornerstones of treatment of type 2 diabetes are diet and exercise, which can have a substantial effect on achieving targets for glycemic control. In an analysis of 11 trials, researchers found that a low-glycemic-index diet reduced the A1C value by an average of 0.5%.[2] Not only did a low-glycemic-index diet promote a reduced incidence of hyperglycemia, one trial demonstrated that it helped prevent hypoglycemia as well.

Another systematic review and meta-analysis focused on the effect of structured exercise training on metabolic outcomes among individuals with type 2 diabetes.[3] Exercise reduced A1c by a mean value of 0.67%, and aerobic exercise, resistance training, and both exercise modalities combined had a similar effect on glycemic control. There was a dose-response effect of exercise in reducing A1c, and physical activity advice alone failed to change A1c values. In another review, exercise was also found to reduce serum triglyceride levels and increase lean body mass.[4]

Nonetheless, most patients with type 2 diabetes do not achieve A1c targets with diet and exercise alone. Physicians face a difficult choice in how to initiate medical therapy for diabetes, particularly as the number of treatment options have expanded in the last 5 years. With this in mind, the current analysis, funded by the Agency for Healthcare Research and Quality, provides insights into the efficacy and safety of noninsulin treatment of diabetes.


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