Effects of glucagon-like peptide-1 receptor agonists on metabolic outcomes in antipsychotic-treated patients with schizophrenia: A systematic review and meta-analysis.

BACKGROUND: Individuals with schizophrenia have markedly increased cardiometabolic morbidity, largely attributable to antipsychotic-induced weight gain, insulin resistance, and dyslipidemia, particularly with clozapine- and olanzapine-based regimens. This systematic review and meta-analysis evaluated the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in antipsychotic-treated patients with schizophrenia. METHODS: PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception to September 16, 2025 for randomized clinical trials comparing GLP-1RAs with placebo or standard care. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was prospectively registered in PROSPERO (CRD420251177261). Random-effects models were used to pool mean differences (MDs) and risk ratios (RRs). RESULTS: Eight randomized clinical trials including 523 participants were analyzed. GLP-1RAs significantly reduced body weight (MD -6.47; 95% CI, -9.61 to -3.32), body mass index (MD -2.83; 95% CI, -3.81 to -1.86), waist circumference (MD -5.35; 95% CI, -6.60 to -4.09), and glycated hemoglobin levels (MD -0.32; 95% CI, -0.39 to -0.26) compared with placebo or standard care. Exploratory subgroup analyses suggested marked differences across individual agents: exenatide showed a smaller and non-significant reduction in body weight, liraglutide showed a significant moderate reduction, and semaglutide showed the largest reduction. No significant effects were observed for fasting insulin, lipid parameters, or blood pressure. Gastrointestinal adverse events were more frequent with GLP-1RAs. CONCLUSIONS: In this systematic review and meta-analysis, GLP-1RAs were associated with clinically meaningful improvements in anthropometric and glycemic outcomes in antipsychotic-treated patients with schizophrenia, with acceptable tolerability primarily characterized by gastrointestinal adverse events.