Glucagon‐like peptide‐1 receptor agonist treatment reduces body weight and improves glycaemic outcomes in patients with concurrent overweight/obesity and type 1 diabetes: A systematic review and meta‐analysis

Abstract Aims This systematic review and meta‐analysis evaluated the long‐term efficacy and safety of glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) as adjunctive therapies for individuals with type 1 diabetes (T1D) and overweight or obesity. Materials and Methods A literature search was conducted in June 2023 and updated in June 2025. Eligible studies included adults with T1D, body mass index ≥25 kg/m 2 , and GLP‐1RA treatment alongside insulin for ≥12 weeks. Changes in body weight, HbA1c, and insulin dose were expressed as mean differences (MDs) with 95% confidence intervals (CIs). Safety outcomes were assessed using odds ratios (ORs) with 95% CIs. Data were pooled using random‐effects models. Results Exactly 13 studies met the inclusion criteria. GLP‐1RA treatment was associated with a body weight reduction of 4.31 kg (95% CI: 3.61–5.00 kg) and a HbA1c reduction of 0.25% (95% CI: 0.18–0.32%). Across all studies, insulin dosage was reduced by 9.24 U/day (95% CI: 7.04–11.45 U/day). Subgroup analysis identified that semaglutide achieved the greatest reductions in all outcome measures. Hypoglycaemic episodes were increased (OR = 1.34; 95% CI: 1.02–1.76), while hyperglycaemic episodes decreased (OR: 0.69, 95% CI: 0.56–0.87). Gastrointestinal adverse events, including nausea and vomiting, were significantly more frequent with GLP‐1RA treatment, though no increase in serious adverse events was observed. Conclusions GLP‐1RAs are effective for body weight reduction and glycaemic improvement in individuals with T1D and overweight/obesity, with acceptable safety profiles. These findings provide evidence that GLP‐1RAs can be effectively and safely used as adjunctive therapy to insulin in people with T1D, but additional robust randomised clinical trials are needed.