JAMA study shows that metformin is safest first-line therapy for type 2 diabetes

Twitter summary: JAMA study shows that metformin is safest first-line therapy for type 2 diabetes – future GRADE study to show best second-line therapy

The journal JAMA Internal Medicine recently published results from a study comparing the effectiveness of four different classes of drugs for type 2 diabetes: metformin, sulfonylureas, TZDs, and DPP-4 inhibitors. The study was a “retroactive cohort study,” meaning that it looked back at a group of patients and analyzed their health outcomes. The results showed that metformin is the best drug to begin treatment of type 2 diabetes – patients starting drugs other than metformin had on average a significantly greater risk of needing additional medications down the road (another oral pill and/or insulin), without any additional health benefits (e.g., they did not have reduced hypoglycemia, ER visits, or heart problems).

Surprisingly, the research found that despite guidelines recommending metformin, only 58% of patients actually used metformin as their first diabetes medication. The study unfortunately did not include GLP-1 agonists – a common injectable drug class for treating type 2 diabetes that has been available since 2005. It was very depressing in our view that GLP-1 wasn’t assessed. In the future, we look forward to the results of the GRADE study, which aims to conclude which second-line drug for type 2 diabetes is most effective; unfortunately, however, this study will not include SGLT-2 inhibitors or any fixed dose combination drugs, which we believe will be a very limiting factor from understanding real life outcomes. While we understand that few risks are attractive for those designing the studies, we believe SGLT-2 research could have been included as a useful arm.  For more resources on treatment recommendations for type 2 diabetes, please see the ADA/EASD guidelines, the AACE guidelines, or the IDF guidelines. ­–AJW