The comparative effectiveness of bariatric operations versus GLP-1 RAs: a systematic review and meta-analysis

Obesity is a global health crisis associated with increased morbidity and mortality, primarily due to cardiometabolic complications such as type 2 diabetes mellitus and cardiovascular disease. While glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have gained traction as pharmacologic interventions for weight loss and glycemic control, metabolic and 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.

To systematically review and quantitatively synthesize observational comparative effectiveness evidence evaluating mortality, major adverse cardiovascular events, and glycemic outcomes among patients with obesity treated with MBS versus GLP-1 RA therapy.

Systematic review and meta-analysis of observational comparative effectiveness studies.

A systematic review and meta-analysis were performed on observational comparative effectiveness cohort studies evaluating outcomes among patients with obesity treated with either MBS or GLP-1 RAs. 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 was conducted in February 2025 to identify studies reporting all-cause mortality, major adverse cardiovascular events, or hemoglobin A1C outcomes. Pooled relative risks (RRs) for dichotomous outcomes and weighted mean differences (WMDs) for continuous outcomes were calculated using random-effects models.

Six retrospective cohort studies involving 208,751 patients were included. In pooled analysis, MBS was associated with a significant reduction in major adverse cardiovascular events compared with GLP-1 RA therapy (RR = .59; 95% confidence interval [CI]: .46-.77). For all-cause mortality, MBS was associated with a nonsignificant trend toward lower risk compared with GLP-1 RA therapy (RR = .66; 95% CI: .41-1.07). The pooled WMD in final A1C favored MBS over GLP-1 RA therapy (WMD = -1.31%; 95% CI: -1.66 to .96).

Both MBS and GLP-1 RA therapies provide important cardiometabolic benefits for individuals with obesity. MBS was associated with more favorable cardiovascular and glycemic outcomes, with a nonsignificant trend toward reduced all-cause mortality. Both treatment strategies remain important components of contemporary obesity management.