Metabolic Surgery for Obese Type 2 Diabetes: Korean Multicenter Cohort Study

Background: Metabolic/bariatric surgery is an effective treatment for obesity and type 2 diabetes mellitus (T2DM), with sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) being the most common procedures. However, comparative data on their metabolic benefits in East Asian populations are limited. Methods: This multicenter retrospective cohort study assessed outcomes of SG and RYGB in Korean adults (BMI ≥ 30 kg/m²) with T2DM who underwent surgery between January 2019 and June 2021. The primary outcome was complete T2DM remission at 1 and 2 years postoperatively. Follow-up data were available for 271 patients at 1 year and 169 at 2 years. Results: Unadjusted analysis showed lower complete remission rates in the RYGB group than the SG group at both 1 year (51.4% vs. 66.3%, p = 0.029) and 2 years (50.0% vs. 62.9%, p = 0.033). After adjustment using inverse probability of treatment weighting (IPTW), the pattern reversed in favor of RYGB (1 year: 67.5% vs. 48.2%; 2 years: 64.4% vs. 46.9%), though differences were not statistically significant (p = 0.127 and p = 0.373). Multivariable logistic regression identified shorter duration of T2DM and absence of insulin use as independent predictors of remission; surgical procedure type was not. Conclusions: After adjusting for baseline differences, no statistically significant difference in T2DM remission was observed between SG and RYGB at 1 and 2 years in Korean patients with BMI ≥ 30 kg/m². These findings should be interpreted with caution given the modest sample size and limited follow-up. Prospective studies are needed to validate these findings and support clinical decision-making.