Patients who achieved an A1c level < 6.5% after metabolic bariatric surgery (MBS) maintained this target in the short and long terms, regardless of whether they continued or discontinued metformin after the procedure.

"The lack of a significant association of metformin continuation with A1c level observed in the current study supports the notion that metformin may not have an additional benefit after MBS," the authors wrote.

This study was led by Dror Dicker, MD, Internal Medicine Department D and Obesity Clinic, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel, and published online in Diabetes, Obesity and Metabolism.

The observational nature of the study and the lack of randomization may have introduced residual confounding. The small number of patients remaining in the final study population limited the generalizability of the findings. The follow-up period of approximately 5 years may not have been sufficient to observe the long-term effects of metformin continuation.

The study received funding from Ariel University. Two authors disclosed receiving grants, personal fees, or nonfinancial support from various sources unrelated to this study.