Effect of Bariatric Surgery on Type 2 Diabetes Remission: A Comprehensive Systematic Review and Meta-analysis

Abstract

Background: Type 2 diabetes mellitus (T2DM) is a major global health problem closely associated with obesity. Bariatric surgery has emerged as an effective intervention for weight reduction and metabolic improvement, with growing evidence supporting its role in diabetes remission. This systematic review and meta-analysis evaluated the effectiveness of bariatric surgery in achieving T2DM remission compared with non-surgical management.

Methods: A systematic search of PubMed/MEDLINE, EMBASE, and SpringerLink databases was conducted for studies published between January 2020 and December 2024. Randomized controlled trials and comparative observational studies involving adults with T2DM undergoing bariatric surgery were included. The primary outcome was complete diabetes remission, defined as HbA1c <6.5% without antidiabetic medication. Secondary outcomes included changes in body mass index (BMI) and HbA1c levels. A random-effects meta-analysis was performed.

Results: Of 351 records identified, 7 studies met the inclusion criteria. Bariatric surgery demonstrated significantly higher rates of diabetes remission compared with non-surgical treatment. Overall, 64.0% (32/50) of surgically treated patients achieved remission compared with 2.8% (7/250) of patients receiving non-surgical management (OR = 25.06; 95% CI: 9.58–65.54; p < 0.00001). Bariatric surgery was also associated with a significant reduction in BMI (MD = −3.81; 95% CI: −4.55 to −3.06; p < 0.00001) and HbA1c levels (MD = −1.44; 95% CI: −1.84 to −1.04; p < 0.00001). Greater BMI reduction was observed among Asian populations than Caucasians.

Conclusion: Bariatric surgery is substantially more effective than non-surgical treatment for achieving T2DM remission and improving glycemic control. These findings support the role of metabolic surgery as a valuable therapeutic option for adults with T2DM, including selected patients with BMI below traditional surgical thresholds.

Keywords: Type 2 Diabetes Mellitus, Bariatric Surgery, Obesity, Diabetes Remission, Glycated Hemoglobin A (HbA1c), Systematic Review and Meta-Analysis