The Comparative Effectiveness of Bariatric Operations vs GLP-1 RAs: A Systematic Review and Meta-analysis

Background Obesity is a global health crisis associated with increased morbidity and mortality, primarily due to cardiometabolic complications such as type 2 diabetes mellitus (T2D) and cardiovascular disease. While glucagon-like peptide-1 receptor agonists (GLP-1RAs) have gained traction as pharmacologic interventions for weight loss and glycemic control, metabolic bariatric surgery (MBS) remains a more established modality with durable long-term outcomes. Direct comparative effectiveness data evaluating their relative associations with mortality, cardiovascular outcomes, and glycemic control remain limited. Methods A systematic review and meta-analysis were performed on observational comparative effectiveness cohort studies evaluating outcomes among patients with obesity treated with either metabolic bariatric surgery or GLP-1 receptor agonists. Two reviewers independently screened studies, extracted data, and assessed methodological quality using the Joanna Briggs Institute critical appraisal checklist. A systematic search of MEDLINE (via PubMed), Embase, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) was conducted in February 2025 to identify studies reporting all-cause mortality, major adverse cardiovascular events (MACE), or hemoglobin A1c (A1C) outcomes. Pooled risk ratios (RRs) for dichotomous outcomes and weighted mean differences (WMDs) for continuous outcomes were calculated using random-effects models. Results Six retrospective cohort studies involving 208,751 patients were included. In pooled analysis, MBS was associated with a significant reduction in MACE compared with GLP-1RA therapy (RR = 0.59; 95% CI: 0.46–0.77). For all-cause mortality, MBS was associated with a non-significant trend toward lower risk compared with GLP-1RA therapy (RR = 0.66; 95% CI: 0.41–1.07). The pooled weighted mean difference in final A1C favored MBS over GLP-1RA therapy (WMD = –1.31%; 95% CI: –1.66 to –0.96). Conclusions Both MBS and GLP-1RA therapies provide important cardiometabolic benefits for individuals with obesity. MBS was associated with more favorable cardiovascular and glycemic outcomes, with a non-significant trend toward reduced all-cause mortality. Both treatment strategies remain important components of contemporary obesity management.