GLP-1 receptor agonist therapy before bariatric surgery: Effects on weight loss and body composition in clinical...

The use of anti-obesity medications, particularly including glucagon-like peptide-1 receptor agonists (GLP1-RA), is expanding and increasingly combined with bariatric surgery (BS). However, evidence on their use preoperative and impact on body composition remains limited.

To compare weight loss and body composition changes in patients undergoing BS with or without prior GLP1-RA treatment.

Retrospective observational study of adults who underwent BS at Clínica Universidad de Navarra (Madrid) between 2017 and 2023.

Overall, 86 patients (mean age, 46.6 ± 12 years; 66% women) were included; 80.2% and 19.8% underwent sleeve gastrectomy and gastric bypass, respectively. Preoperative GLP1-RA therapy (63.4% liraglutide and 36.6% semaglutide) was prescribed in 34.8% of patients for a mean of 21.7 ± 15.9 weeks. Adverse events were mild and mostly gastrointestinal symptoms. Patients treated with GLP1-RA achieved greater weight loss preoperatively (5.1% ± 4.9% vs. 2.4% ± 3.7%; p = 0.005) and at 1 month postoperatively (15.4% ± 5.2% vs. 13.0% ± 3.8%; p = 0.03), but not at 6 months. Prior to BS, fat mass was lower in the GLP1-RA group (53.3 kg [95% CI 50.7-56.0] vs. 58.6 kg [95% CI 56.6-60.5]; p = 0.01), whereas no differences in lean mass or body composition were observed at 6 months between the two groups.

Preoperative GLP1-RA therapy resulted in greater preoperative weight and fat mass reduction without additional lean mass loss. Larger prospective studies are warranted to define the long-term role of GLP1-RA therapy before BS.