Metabolic and bariatric surgery for patients with obesity type 1 diabetes mellitus: A comprehensive updated systematic review and meta‐analysis
Year: 2026
Type: review
Study designs: Systematic Review, Meta-Analysis
Abstract: Aims This systematic review evaluated the impact of metabolic and bariatric surgery (MBS) on weight loss, glycaemic control, insulin requirements and postoperative complications. Methods A PRISMA‐compliant, PROSPERO‐registered systematic review and meta‐analysis (CRD42025123500) was conducted. Medline, PubMed, Embase, Scopus and CENTRAL were searched. Primary outcomes were changes in body weight, BMI, HbA1c and insulin requirements following MBS. Risk of bias was assessed using ROBINS‐I and RoB‐2, and certainty of evidence using GRADE. Results Twenty‐two studies, including 1324 adults with type 1 diabetes mellitus (mean age 42.2 ± 11.6 years; mean follow‐up 31.6 ± 18.2 months), were analysed. Of 753 participants with reported sex, 74.6% were women ( n = 562). A total of 1304 procedures were performed, most commonly Roux‐en‐Y gastric bypass (44.5%; n = 580) and sleeve gastrectomy (39.2%; n = 512), followed by adjustable gastric banding (13.0%; n = 170). Meta‐analysis demonstrated significant reductions in body weight (mean difference 29.55 kg; 95% CI 25.72 to 33.39; I 2 = 20%) and BMI (11.35 kg/m 2 ; 95% CI 10.36 to 12.34; I 2 = 32%). HbA1c decreased by 4 mmol/mol (95% CI 2.05 to 6.78; I 2 = 19%), and insulin requirements declined by 43%–48% (0.20 U/kg; 95% CI 0.13 to 0.26; I 2 = 58%). Postoperative complications included diabetic ketoacidosis (15/182, 8%) and severe hypoglycaemia (21/516, 4%); any complication occurred in 21/495 (4%). Evidence quality was low. Conclusion MBS achieves weight loss and reduces insulin requirements in adults with type 1 diabetes mellitus and obesity, but glycaemic improvements are minimal. Given the observational evidence base and inconsistent safety reporting, true metabolic risk remains uncertain. High‐quality prospective studies with standardised outcome definitions are needed.
Source: Diabetic Medicine
DOI: 10.1111/dme.70305
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7142640276