Effect of Banded Roux-en-Y Gastric Bypass versus Sleeve Gastrectomy on Diabetes Remission at 5 Years Among Patients with Obesity and Type 2 Diabetes: A Blinded Randomized Clinical Trial

<b>Objective:</b> To determine whether silastic-ring laparoscopic Roux-en-Y gastric bypass (SR-LRYGB) or laparoscopic sleeve gastrectomy (LSG) produces superior diabetes remission at 5 years. <p><b>Research Design and Methods: </b>In a single-centre double-blind trial, 114 adults with type 2 diabetes and BMI 35-65kg/m²<b> </b>were randomized to SR-LRYGB or LSG (1:1; stratified by age group, BMI group, ethnicity, diabetes duration and insulin therapy) using a web-based service. Diabetes and other metabolic medications were adjusted according to a prespecified protocol. The primary outcome was diabetes remission assessed at 5 years, defined by HbA1c <6% (42mmol/mol) without glucose-lowering medications. Secondary outcomes included changes in weight, cardiometabolic risk factors, quality of life, and adverse events. </p> <p><b>Results:</b> Diabetes remission after SR-LRYGB vs LSG occurred in 25/53 (47%) vs 18/55 (33%), adjusted odds ratio 4.5; 95% CI 1.6, 15.5; P=0.009; and 4.2; 95% CI 1.3, 13.4; P=0.015 in the intention-to-treat analysis. Percentage body weight loss was greater after SR-LRYGB than after LSG (absolute difference, 10.7%; 95% CI 7.3, 14.0; P<0.001). Improvements in cardiometabolic risk factors were similar, but high-density lipoprotein cholesterol increased more after SR-LRYGB. Early and late complications were similar in both groups. General health and physical functioning improved after both types of surgery, with greater improvement in physical functioning after SR-LRYGB. People of Māori or Pacific ethnicity (26%) had lower incidence of diabetes remission than those of European or other ethnicities (2/25 vs 41/83, P<0.001). </p> <p><b>Conclusions: </b>SR-LRYGB provided superior diabetes remission and weight loss compared to LSG at 5 years, with similarly low risk of complications. </p>