Short-term effectiveness of metabolic surgery in nonobese diabetic patients: A systematic review and meta-analysis

Aim: The aim of this study was to assess the safety and short-term effectiveness of metabolic surgery (MS) in nonobese diabetic patients. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was used in this systematic review. The search for evidence was performed in the Medline (PubMed), Embase, Cochrane (CENTRAL), LILACS, and ClinicalTrials.gov databases from the inception to February 2023. The main eligibility criteria were nonobese adults (body mass index [BMI] <30 kg/m2) with type 2 diabetes mellitus (T2DM) undergoing MS. T2DM remission rate, glycemic parameters, and weight loss were measured before and after surgery. Complication rate was also described. Outcomes were aggregated and the quality of evidence was sorted. Heterogeneity was assumed when I2 >50%. The random-effects model was used to perform a proportional meta-analysis. Results: Twenty-one studies were included (n = 835). The overall rate of diabetes remission was 50.1% (95% confidence interval [CI] = 43.8%–56.1%; P = 0.993; I2 = 92%). The mean reduction of glycated hemoglobin and fasting glucose was 2.42% (95% CI = 1.91%–2.93%; P < 0.00001; I2 = 89%) and 70.60 mg/dL, respectively. A drop of 3.34 points (95% CI = 1.59–5.09; P < 0.0002; I2 = 95%) was observed in the HOMA-IR, and the mean postprandial glycemia was 123.27 mg/dL. No marked weight loss was observed (−3.80 kg/m2 in BMI; 95% CI = 2.70–4.91; P < 0.00001; I2 = 95%). There was no postoperative mortality, and the overall postoperative complication rate was about 12%. The certainty of evidence was low or very low. Conclusion: MS could be effective in the surgical approach of nonobese diabetic patients, but further long-term, more robust studies are needed to strengthen the evidence.