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.

Liraglutide treatment for 35 days reduced body weight and BMI in adults with obesity.

• Twenty adults with obesity participated in a crossover randomized controlled trial.
• Participants received liraglutide 3.0 mg/day or placebo for 35 days.
• Body weight and BMI were both significantly reduced at the end of the liraglutide phase compared to placebo.
• This was a secondary analysis of a randomized placebo-controlled crossover study.

Liraglutide reduced total and regional mass including trunk, hip, and extremity mass.

• Reductions in mass were observed across multiple body regions: trunk, hip, and extremities.
• Body composition was assessed by dual-energy X-ray absorptiometry (DXA) at the end of each treatment phase.
• Both fat and lean components contributed to the observed regional mass reductions.

Absolute fat-free mass was slightly but significantly lower following liraglutide treatment.

• Although the reduction in absolute fat-free mass was described as slight, it reached statistical significance.
• Absolute lean mass in the trunk and extremities also decreased with liraglutide treatment.
• Despite these absolute reductions, relative lean mass and fat-free mass percentages remained stable at treatment completion.
• The preservation of relative body composition suggests that the reductions in lean and fat-free mass were proportional to overall weight loss.

Relative lean mass and fat-free mass percentages remained stable at the completion of liraglutide treatment.

• Despite absolute decreases in lean and fat-free mass, the percentage of lean and fat-free mass relative to total body mass did not significantly change.
• This indicates that liraglutide's early weight loss did not disproportionately reduce lean or fat-free tissue relative to fat mass.
• Body composition was measured using DXA at the end of each 35-day phase.

The study assessed circulating markers of muscle and bone metabolism including the Myostatin-Activin-Follistatin-IGF-1 axes over 5 weeks of treatment.

• Hormones were measured by ELISA at baseline and at each of 6 weekly visits over 5 weeks.
• The hormonal axes examined included myostatin, activin, follistatin, and IGF-1, which are regulators of muscle and bone metabolism.
• The study aimed to identify circulating hormonal changes associated with early liraglutide-induced body composition changes.
• The authors note that further research is needed to clarify the relationship between these hormonal changes and clinical outcomes.

The authors conclude that further research is warranted to identify strategies to preserve muscle mass during GLP-1RA-induced weight loss.

• Short-term liraglutide treatment reduces total and regional mass without altering relative body composition.
• The clinical significance of the absolute reductions in lean and fat-free mass requires further study.
• The authors emphasize the need to study hormonal changes and develop strategies to preserve muscle mass during weight loss with GLP-1RAs.