But differences in total remission of diabetes narrowed over time. 

Investigators previously reported pooled three-year outcomes of four randomised, single-centre trials of bariatric surgery or medical management for patients with type 2 diabetes (STAMPEDE, TRIABETES, SLIMM-T2D and CROSSROADS).* They now report outcomes during median follow up of 11 years in 262 patients (mean age, 50 years; mean body mass index [BMI], 36kg/m²). About 80% of patients randomised to surgery underwent Roux-en-Y gastric bypass or sleeve gastrectomy. Those randomised to medical management received various structured programs considered more intense than usual care; one-quarter of these patients eventually crossed over to surgery.

Selected results are as follows:

• at seven years, mean glycosylated haemoglobin (HbA_1c) had decreased by 1.6 percentage points in the bariatric surgery group versus 0.2 percentage points in the medical management group in an intent-to- treat analysis
• Roux-en-Y gastric bypass and sleeve gastrectomy were similarly effective, and both were slightly superior to gastric banding
• weight loss at 12 years favoured surgery (19% vs 8% of body weight, in an analysis that accounted for the actual treatment received)
• diabetes remission rates favoured surgery at one year (50% vs 0.5%), but the difference declined by 12 years (12.7% vs 0.0%)
• medication use continued at seven years for nearly all medically managed patients but was eliminated for about 40% of surgery patients
• subgroups with BMIs below 5kg/m² and 35kg/m² or above had similar weight loss and HbA_1c reductions
• major adverse cardiovascular events were low and similar in both treatment groups, whereas gastrointestinal symptoms and nutritional deficiencies were more common with surgery.

Comment: These results are helpful for clinicians counselling patients about long-term diabetes management. The high rate of diabetes remission in those undergoing surgery faded over time, but medication use was eliminated for many surgery patients. The substantial weight loss in the medical management group suggests the programs were far more intense than is typical for routine practice, and therefore perhaps difficult to replicate.
* Published results of the four studies are available at STAMPEDE (NEJM JW Gen Med Apr 1 2017 and N Engl J Med 2017; 376: 641-651), TRIABETES, SLIMM-T2D and CROSSROADS.

Thomas L. Schwenk, MD, Professor Emeritus, Family and Community Medicine, University of Nevada School of Medicine, Reno, USA.

Courcoulas AP, et al. Long-term outcomes of medical management vs bariatric surgery in type 2 diabetes. JAMA 2024; 331: 654-664.

This summary is taken from the following Journal Watch titles: General Medicine, Ambulatory Medicine.