Effectiveness of Roux-en-Y Gastric Bypass in Patients with Type 2 Diabetes: A Meta-analysis of Randomized Controlled Trials

This meta-analysis aimed to evaluate the effectiveness of Roux-en-Y gastric bypass (RYGB) in people living with type 2 diabetes mellitus (T2DM). A comprehensive search was conducted in the PubMed database up to January 2024. A random-effects model was used to calculate the pooled standard mean differences (SMDs) and odds ratios (ORs). Ten studies were included in our review. The RYGB group demonstrated significantly better outcomes compared to the non-surgical group in multiple measures. These included higher triple criteria compliance rates (OR 9.04, 95% CI 3.22-25.36), complete T2DM remission (OR 15.37, 95% CI 4.42-53.41), and partial T2DM remission (OR 11.49, 95% CI 3.57-37.03). Additionally, improvements were observed in glycated hemoglobin A1c (HbA1c) levels (SMD - 1.41, 95% CI - 2.22 to - 0.61), with HbA1c < 6.0% (OR 8.54, 95% CI 3.38-21.62) and HbA1c < 7.0% (OR 5.62, 95% CI 3.20-9.86). Fasting blood glucose (FBG) levels also showed improvement (SMD - 0.43, 95% CI - 0.71 to - 0.14), with a higher proportion achieving FBG < 100 mg/dl (OR 11.83, 95% CI 4.75-29.43). Other notable outcomes included significant percentage of total weight loss (%TWL: SMD 1.88, 95% CI 1.39-2.37), reductions in body mass index (BMI: SMD - 2.28, 95% CI - 3.52 to - 1.04), and improvements in lipid profiles, including low-density lipoprotein (LDL) levels (SMD - 1.01, 95% CI - 1.91 to - 0.11) and LDL < 2.59 mmol/L (OR 3.65, 95% CI 1.94-6.87). In addition, high-density lipoprotein<bold> (</bold>HDL) levels increased (SMD 1.30, 95% CI 0.55-2.05), while triglycerides (SMD - 1.11, 95% CI - 1.70 to - 0.52), systolic blood pressure (SBP: SMD - 0.38, 95% CI - 0.70 to - 0.06), and diastolic blood pressure (DBP: SMD - 0.41, 95% CI - 0.63 to - 0.18) decreased. A greater proportion of patients in the RYGB group achieved SBP < 130 mmHg (OR 3.15, 95% CI 1.61-6.13). Moreover, reductions were noted in insulin use (OR 0.25, 95% CI 0.14-0.46), diabetes medication use (SMD - 1.95, 95% CI - 3.32 to - 0.57), and peripheral neuropathy (OR 0.13, 95% CI 0.02-0.79). However, no significant differences were observed in hypertension medication use or retinopathy between the two groups. RYGB was found to be effective in improving glycemic control, promoting weight loss, enhancing lipid profiles, and managing blood pressure. It also significantly reduced the need for postoperative diabetes medications and the incidence of diabetic peripheral neuropathy in people living with T2DM.