Sleeve gastrectomy versus roux-en-Y gastric bypass for remission of type 2 diabetes mellitus and obesity: systematic review and meta-analysis of randomized controlled trials

Objective: Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are common bariatric procedures employed to treat obesity and type 2 diabetes mellitus (T2DM). This meta-analysis of RCTs systematically compares the therapeutic effects between RYGB and SG in T2DM patients with obesity, with particular focus on evaluating the impacts of varying remission criteria (e.g., HbA1c thresholds) and follow-up durations on treatment outcomes. Methods: 22 RCTs were included in the meta-analysis. A random-effects model was used to compare outcomes related to T2DM and obesity between groups, and trial sequential analyses verified the stability of these outcomes. Results: This study included a total of 1500 patients. Overall, RYGB demonstrated superior treatment outcomes across different follow-up periods (1 year, 3 years, and 5 years). When using a remission target of HbA1c < 6.0 or HbA1c < 6.5, the evidence favored the RYGB group, which exhibited higher remission rates than the SG group. RYGB showed better T2DM remission rates at 1- and 3-years post-surgery, although the difference at 5 years was not statistically significant. Additionally, HbA1c levels at 1 and 3 years were lower in the RYGB group, with no significant difference at 5 years. Furthermore, RYGB resulted in greater reductions in total cholesterol and LDL compared to SG. Conclusions: This study reveals the impact of different T2DM remission targets on the assessment of surgical outcomes. Meta-analysis revealed that RYGB yields superior short-term (< 3 years) T2DM remission rates compared to SG across all evaluated thresholds, while also demonstrating enhanced efficacy in weight control and dyslipidemia management.