Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D): Study rationale, design, and methods

Diabetes Obes Metab. 2022 Jul;24(7):1206-1215. doi: 10.1111/dom.14680. Epub 2022 Mar 16.


Aims: Long-term data from randomized clinical trials comparing metabolic (bariatric) surgery versus a medical/lifestyle intervention for treatment of patients with obesity/overweight and type 2 diabetes (T2D) are lacking. The Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes (ARMMS-T2D) is a consortium of four randomized trials designed to compare long-term efficacy and safety of surgery versus medical/lifestyle therapy on diabetes control and clinical outcomes.

Materials and methods: Patients with T2D and body mass index (BMI) of 27-45 kg/m2 who were previously randomized to metabolic surgery (Roux-en-Y gastric bypass, adjustable gastric band, or sleeve gastrectomy) versus medical/lifestyle intervention in the STAMPEDE, SLIMM-T2D, TRIABETES, or CROSSROADS trials have been enrolled in ARMMS-T2D for observational follow-up. The primary outcome is change in glycated haemoglobin after a minimum 7 years of follow-up, with additional analyses to determine rates of diabetes remission and relapse, as well as cardiovascular and renal endpoints.

Results: In total, 302 patients (192 surgical, 110 medical/lifestyle) previously randomized in the four parent studies were eligible for participation in the ARMMS-T2D observational study. Participant demographics were 71% white, 27% African-American and 68% female. At baseline: age, 50 ± 8 years; BMI, 36.5 ± 3.5 kg/m2 ; duration of diabetes, 8.8 ± 5.6 years; glycated haemoglobin, 8.6% ± 1.6%; and fasting glucose, 168 ± 64 mg/dl. More than 35% of patients had a BMI <35 kg/m2 .

Conclusions: ARMMS-T2D will provide the largest body of long-term, level 1 evidence to inform clinical decision-making regarding the comparative durability, efficacy and safety of metabolic surgery relative to a medical/lifestyle intervention among patients with T2D, including those with milder class I obesity or mere overweight.

Keywords: Roux-en-Y gastric bypass; adjustable gastric band; bariatric surgery; clinical trial; diabetes remission; lifestyle; metabolic surgery; obesity; sleeve gastrectomy; type 2 diabetes.

Publication types

  • Observational Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Bariatric Surgery*
  • Diabetes Mellitus, Type 2* / complications
  • Diabetes Mellitus, Type 2* / surgery
  • Female
  • Gastrectomy / methods
  • Gastric Bypass* / methods
  • Glycated Hemoglobin / metabolism
  • Humans
  • Male
  • Middle Aged
  • Obesity / surgery
  • Obesity, Morbid* / surgery
  • Overweight / complications
  • Overweight / therapy
  • Randomized Controlled Trials as Topic
  • Treatment Outcome


  • Glycated Hemoglobin A