Type 2 Diabetes Relapse after Roux-en-Y Gastric Bypass and Sleeve Gastrectomy: A Systematic Review and Meta-Analysis.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) remission after bariatric surgery may not be durable, and relapse after initial remission is an increasingly important outcome. This systematic review and meta-analysis compared the risk of T2DM relapse after Roux-en-Y gastric bypass (RYGB) versus sleeve gastrectomy (SG) in patients with obesity and T2DM who achieved postoperative remission. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched from inception to April 20, 2026. Eligible studies included adults with obesity and preoperative T2DM who underwent primary RYGB or SG and reported T2DM relapse after remission. Hazard ratios (HRs) and odds ratios (ORs) were pooled separately using random-effects models. Study quality was assessed using the Newcastle-Ottawa Scale or Cochrane risk of bias tool. RESULTS: Nine studies comprising 11 cohorts and 24,228 patients were included; 9,674 underwent SG and 14,554 underwent RYGB. The mean age was 49.5 years, 31.4% were male, the mean BMI was 47.7 kg/m², and the mean T2DM duration was 5.7 years. Compared with SG, RYGB was associated with a significantly lower risk of T2DM relapse in HR-based analyses (HR, 0.67; 95% CI, 0.59-0.76; P < 0.0001; I² = 23.1%) and OR-based analyses (OR, 0.63; 95% CI, 0.52-0.76; P < 0.0001; I² = 0%). Subgroup analysis, sensitivity analysis, and publication-bias analysis supported the robustness of the findings. CONCLUSIONS: This systematic review and meta-analysis suggests that RYGB was associated with a lower risk of T2DM relapse after initial remission than SG. However, given the predominantly retrospective nature of the available evidence, these findings should be interpreted cautiously and require confirmation in well-designed prospective studies.