Dynamics of Body Composition and Metabolic Risk in Adolescents With Obesity Under GLP-1 Receptor Agonist Therapy.

AIM: To explore changes in body composition in adolescents with obesity treated with glucagon-like peptide-1 receptor agonist (GLP-1 RA) and their association with metabolic syndrome (MetS) components. METHODS: This real-world retrospective study included adolescents (12-18 years) with obesity who received multidisciplinary lifestyle-based obesity care between 2020 and 2024. GLP-1 RA therapy (liraglutide or semaglutide) was prescribed and dosed on an individualised basis. BMI and muscle-to-fat ratio (MFR) z-scores (by bioimpedance), and MetS components (glucose intolerance, hypertension, and dyslipidemia) were evaluated and compared with patients not receiving GLP-1 RA at corresponding time points. Multivariable regression analyses adjusted for sex, age, physical activity, and length of follow-up evaluated contributors for improvement in body composition. RESULTS: Of 67 eligible adolescents, 41 (61.2%) received GLP-1 RA therapy. The GLP-1 RA-treated group experienced greater improvements in BMI z-scores (-0.34 [-0.57, -0.07] vs. -0.07 [-0.17, 0.05], p < 0.001), and MFR z-scores (0.41 [0.12, 0.56] vs. 0.13 [0.01, 0.25], p = 0.007) compared to those without GLP-1 RA therapy. GLP-1 RA treatment duration was identified as the sole contributor to BMI and MFR z-score improvements (R = 0.515, p < 0.001 and R = 0.231, p = 0.012, respectively). A 0.25-unit decrease in BMI z-score and a 0.25-unit increase in MFR z-score were associated with 2.8-fold and 1.8-fold higher odds of MetS component improvement, respectively. CONCLUSION: Adolescents with obesity under GLP-1 RA therapy combined with lifestyle intervention demonstrated improvements in body composition and MetS components.