Medical Management vs. Bariatric Surgery Outcomes in Diabetes

Quick Takes

  • Bariatric surgery led to superior glycemic control compared with medical/lifestyle intervention (between-group difference in HbA1c of 1.4% at 7 years and 1.1% at 12 years), with less diabetes medication usage and higher diabetes remission rates.
  • No differences in major cardiovascular adverse events were observed; however, anemia, fractures, and gastrointestinal adverse events were more common after bariatric surgery.

Study Questions:

What is the long-term glycemic control and safety of bariatric surgery compared to medical/lifestyle for the management of type 2 diabetes?


Data were used from four US single-center randomized trials conducted between May 2007 and August 2013 as part of the ARMMS-T2D (Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes) project. Observational follow-up was conducted through July 2022. Participants were originally randomized to either medical/lifestyle management or one of the following three bariatric surgical procedures: Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric banding. The primary outcome for the present analysis was a change in glycated hemoglobin (HbA1c) from baseline to 7 years. Data are reported for up to 12 years.


From the 305 eligible participants, 262 participants (86%) enrolled in long-term follow-up were used for the present pooled analysis. The mean (SD) age of participants was 49.9 (8.3) years, mean (SD) body mass index was 36.4 (3.5), 68.3% were women, 31% were Black, and 67.2% were White. During follow-up, 25% of participants randomized to undergo medical/lifestyle management underwent bariatric surgery. The median follow-up was 11 years. At 7 years, HbA1c decreased by 0.2% (95% confidence interval [CI], −0.5% to 0.2%) from a baseline of 8.2% in the medical/lifestyle group and by 1.6% (95% CI, −1.8% to −1.3%), from a baseline of 8.7%, in the bariatric surgery group. The between-group difference was −1.4% (95% CI, −1.8% to −1.0%; p < 0.001) at 7 years and −1.1% (95% CI, −1.7% to −0.5%; p = 0.002) at 12 years. Fewer anti-diabetes medications were used in the bariatric surgery group. Diabetes remission was greater after bariatric surgery (6.2% in the medical/lifestyle group vs. 18.2% in the bariatric surgery group; p = 0.02) at 7 years and at 12 years (0.0% in the medical/lifestyle group vs. 12.7% in the bariatric surgery group; p < 0.001). There were four deaths (2.2%), two in each group, and no differences in major cardiovascular adverse events. Anemia, fractures, and gastrointestinal adverse events were more common after bariatric surgery.


The authors conclude that after 7-12 years of follow-up, participants originally randomized to undergo bariatric surgery had superior glycemic control with less diabetes medication use and higher rates of diabetes remission, compared with medical/lifestyle intervention.


The pooled analysis results suggest that bariatric surgery is associated with long-term improvements in glycemic control among adults with type 2 diabetes. Given the higher rates of adverse events with bariatric surgery (i.e., fractures and gastrointestinal), further comparison of the long-term effects of bariatric surgery versus medical/lifestyle interventions, where glucagon-like peptide-1 agonists are used, is warranted.

Clinical Topics: Diabetes and Cardiometabolic Disease, Prevention

Keywords: Bariatric Surgery, Diabetes Mellitus, Type 2

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