Effects of liraglutide treatment for 35-days on total and regional fat free, lean, and bone mass, and on the Myostatin-Activin-Follistatin-IGF-1 axes: a secondary analysis of a randomized placebo-controlled crossover study.

BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are used to treat obesity and metabolic diseases, yet their early impact on body composition and circulating regulators of muscle and bone remain unclear. This study aimed to assess early effects of liraglutide on total and regional body composition and associated changes in circulating markers of muscle and bone metabolism. METHODS: Twenty adults with obesity received liraglutide 3.0 mg/day or placebo for 35 days in this crossover randomized controlled trial. In this secondary analysis, body composition was assessed by dual-energy X-ray absorptiometry at the end of each phase, while hormones were measured by ELISA at baseline and at each of 6 weekly visits over 5 weeks. RESULTS: Liraglutide reduced body weight, BMI, and total and regional mass (trunk, hip, and extremities). Absolute fat-free mass was slightly but significantly lower. Absolute lean mass in the trunk and extremities decreased, whereas relative lean mass and fat-free mass percentages remained stable at treatment completion. CONCLUSIONS: Short-term liraglutide treatment reduces total and regional mass without altering relative body composition. Further research is warranted to confirm and clarify the clinical significance of these changes, to further study hormonal changes and identify strategies to preserve muscle mass during weight loss.