Evaluating Weight Loss Associated with Bariatric Surgery After Liraglutide Use: A Matched Population-Level Retrospective Cohort Study.

INTRODUCTION: Glucagon-like peptide 1 (GLP-1) analogues are an emerging class of medications used to treat obesity. While studies show that postoperative liraglutide use is an effective adjunct treatment for patients with unsuccessful weight loss after bariatric surgery, the impact of preoperative liraglutide use on postoperative outcomes remains poorly understood. Therefore, the aim of this study was to determine if postoperative weight loss and comorbidity outcomes differ for patients who use liraglutide before their bariatric surgery. METHODS: Using data from the Ontario Bariatric Registry (OBR), we conducted a retrospective, matched cohort study of patients who underwent a primary bariatric procedure between January 2010 and June 2020. Liraglutide naive patients were matched with preoperative liraglutide users. The primary outcome of interest was percentage total body weight lost (TWL) from baseline to 1-year post-surgery. RESULTS: A total of 1383 liraglutide naive patients were successfully matched to 449 liraglutide users at a ratio of 3:1. 1-year post-surgery; there were differences observed between groups in the primary outcome examined, with a higher TWL observed in the liraglutide naive group (27.52 ± 10.28% liraglutide naive vs. 25.46 ± 9.04% liraglutide users, p < 0.001). CONCLUSIONS: While an increase in weight loss was observed in liraglutide naive patients, both groups had clinically significant weight loss and similar BMIs at 1-year post-surgery. This suggests that preoperative GLP-1 analogue users and GLP-1 analogue naive patients both benefit substantially from bariatric surgery.