Evidence Matters

Bariatric Surgery Superior to Medical Therapy for Long Term Diabetes Control

Background and Purpose:

~35 million Americans (nearly 1 in 10) have type 2 diabetes (T2D), a condition in which a patient’s insulin production is insufficient for proper glycemic control.
Courcoulas et al. set out to determine the long-term durability of glycemic control and safety of bariatric surgery, compared to medical/lifestyle (M/L) management of T2D.

Design, Setting, and Participants
- Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes is a consortium of four randomized trials designed to compare the long-term efficacy and safety of surgery versus M/L therapy on diabetes control and clinical outcomes. The trials were conducted between May 2007 and Aug 2013, with observational follow-up until Jul 2022.
Intervention
- Participants were randomized to undergo either M/L management, Roux-en-Y gastric bypass, sleeve gastrectomy, or adjustable gastric banding.
Primary Outcome and Measures
- The primary outcome was change in hemoglobin A_1c (HbA₁_C) from baseline to 7 years for all participants. Data are reported for up to 12 years.

86% of eligible participants (262/305) enrolled in longitudinal follow-up for this analysis.
- 68.3% women; 31% Black; and 67.2% were White.
- Mean age (SD) was 49.9 (8.3)
- Mean body mass index (SD) was 36.4 (3.5)
25% of patients randomized to undergo M/L management underwent bariatric surgery.
Median follow-up was 11 years.
At 7 years, HbA_1C levels showed a greater decrease in bariatric surgery patients.
- M/L group: 0.2% decrease (95% confidence interval [CI], −0.5% to 0.2%); 8.2% baseline
- Bariatric surgery group: 1.6% decrease (95% CI, −1.8% to −1.3%); 8.7% baseline
Between-group differences in HbA_1C
- HbA_1C at 7 years: −1.4% (95% CI, −1.8% to −1.0%; P < .001)
- HbA_1C at 12 years: −1.1% (95% CI, −1.7% to −0.5%; P = .002)
Fewer anti-diabetes medications were used in the bariatric surgery group.
Diabetes remission was greater after bariatric surgery at 7 years and 12 years.
- 7 years: 6.2% in the M/L group vs 18.2% in the bariatric surgery group; P = .02
- 12 years: 0.0% in the M/L group vs 12.7% in the bariatric surgery group; P < .001
There were 2 deaths in each group and no differences in major cardiovascular events.
Anemia, fractures, and adverse gastrointestinal events were more common after bariatric surgery.

After 7-12 years of follow-up, bariatric surgery patients had superior glycemic control with less diabetes medication use and higher rates of diabetes remission.