Comparison of Benefits and Risks of Metabolic Surgery for Long-Term (Over 5 Years) Weight Loss and Diabetes Remission in Overweight/Obese Patients with Type 2 Diabetes: A Systematic Review and Network Meta-Analysis of Randomized Trials

Background: Although comparisons of the effectiveness of various metabolic surgeries in overweight/obese patients with type 2 diabetes mellitus (T2DM) were reported, there is no evidence of long-terms follow-up.Methods: The randomized controlled trials (RCTs) with 5-year follow-up or more were selected. The network meta-analysis approach was used to compare clinical benefits and assess risks of adverse events incidence. PROSPERO registration number: CRD42023412536.Findings: Fourteen RCTs with 952 patients were identified, while only 808 patients completed the 5-year or longer follow-up (84.9%). There were 7 metabolic surgeries including Sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), Biliopancreatic diversion (BPD), laparoscopic-adjustable gastric banding (LAGB), Greater curvature plication (GCP), One-anastomosis gasric bypass (OAGB), and Biliopancreatic diversion with duodenal switch (BPD/DS). And a non-surgical treatment (NST). The results showed that for the long-term diabetes remission, the benefits of metabolic surgeries ranked as: OAGB>RYGB>SG>NST; In terms of benefits of weight loss, BPD, RYGB, and SG were top three rankings of interventions, while BPD, RYGB, and OAGB were top three rankings of interventions in BMI reduction. OAGB, BPD, and RYGB were top three options for controlling blood pressure. BPD had the best effects in improving blood lipid profile, then RYGB, and NST followed. OAGB, RYGB and SG were ranked the top three highest revision rate of metabolic surgery. With respect to the safety of metabolic surgeries, the qualitative analysis on adverse events suggested that RYGB had lower risks of surgery-associated adverse events, BPD had higher risks of gastrointestinal and cerebrovascular events. Moreover, GCP and OAGB had the least adverse events records.Interpretation: RYGB is the most effective metabolic surgery for the treatment of obesity with T2DM, hypertension, and dyslipidemia and has fewer adverse events, which could be a preferred surgical approach for physicians and patients. BPD has the best effects on reducing weight and lowering blood lipid levels, however, attention should be paid to the prominent gastrointestinal and cerebrovascular adverse events and incidence of complications. It is proved that OAGB has the best efficacy in long-term diabetes remission and blood pressure reduction, especially in the outcome of complete diabetes remission over 5 years with fewer reports on safety that further exploration is required.Funding: This study was supported by National Natural Science Foundation of China (Grant number: 82274343), research on the "quantity-toxin" rule and compatibility reduction of commonly used "toxic" Chinese medicine based on traditional Chinese medicine clinical evidence of diabetes mellitus (Grant number: CI2021A01605).the Fundamental Research Funds for the Central Public Welfare Research Institutes (Grant number: ZZ13-ZD-06) and special Project for Construction of Clinical Medical Research Center of Guang'anmen Hospital, China Academy of Chinese Medical Sciences (2022LYJSZX28).Declaration of Interest: None.