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

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/m 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/m ; 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/m .

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.