Metabolic bariatric surgery as a therapeutic option for patients with type 2 diabetes: A meta-analysis and network meta-analysis of randomized controlled trials

Aim: To compare different types of metabolic surgery with non-surgical therapy for the treatment of type 2 diabetes (T2D). Methods: The present network meta-analysis (NMA) includes randomized clinical trials (duration = 52 weeks) comparing different surgery techniques with non-surgical therapy in diabetes patients. The primary endpoints were endpoint HbA1c, body mass index (BMI) and diabetes remission. The secondary endpoints included fasting plasma glucose, lipid profile, blood pressure, arterial hypertension and dyslipidaemia remission, quality of life and surgical adverse events. Indirect comparisons of different types of surgery were performed by NMA. Mean and 95% confidence intervals for continuous variables, and the Mantel-Haenzel odds ratio for categorial variables, were calculated. Results: The types of surgical procedure included laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), bilio-pancreatic diversion (BPD), greater curvature plication (GCP), one-anastomosis gastric bypass (OAGB) and Duodeno-Jejunal bypass. Thirty-six trials were included. Metabolic bariatric surgery (MBS) was associated with a significantly higher reduction of HbA1c, diabetes remission and BMI compared with medical therapy. In the NMA, a significant reduction of HbA1c was observed with OAGB and SG. Complete diabetes remission significantly increased with all surgical procedures in comparison with nonsurgical therapy, except for GCP. In addition, only BPD, RYGB and OAGB were associated with a significant reduction of BMI. Conclusions: MBS is an effective option for the treatment of T2D in patients with obesity. Further long-term trials of appropriate quality are needed for assessing the risk-benefit ratio in some patient cohorts, such as those with a BMI of less than 35 kg/m2 and aged older than 65 years.