Real-World Use of GLP-1 Receptor Agonist Liraglutide in Adolescents with Obesity: A First Longitudinal Single-Center Analysis from Switzerland

<b>Background:</b> Adolescent obesity remains a challenge with limited treatment options. GLP-1 receptor agonists such as liraglutide (Saxenda^®) have shown efficacy in trials, but real-world data in youth are scarce. <b>Methods:</b> This retrospective longitudinal, non-interventional study analyzed 22 adolescents treated with liraglutide in a Swiss pediatric endocrinology center. All received non-structured nutritional/lifestyle counseling with three-monthly follow-up. BMI standard deviation scores (BMI-SDS) and adverse effects were recorded. <b>Results:</b> The mean age at initiation was 14.9 years (range 12.5-17.5); 15 patients had Southern European immigrant background. Mean treatment duration was 8.2 months (range 1-18). BMI-SDS decreased significantly from +2.63 (IQR +2.4/+2.8) to +2.40 (IQR +2.2/+2.6). Median intra-individual reduction was -0.20 (IQR -0.28/-0.10), <i>p</i> = 0.0003 with large effect size (rb = -0.77). Thirteen patients discontinued treatment, mainly due to insufficient weight loss or mild nausea. In the patients continuing therapy BMI-SDS decreased from +2.59 (IQR +2.4/+2.8) to +2.08 (IQR +1.9/+2.4). No serious adverse events occurred. <b>Conclusions:</b> Liraglutide showed a comparable efficacy to the pivotal clinical trial in reducing BMI-SDS in adolescents, while the side-effect profile was similarly mild and consistent with previously reported data. Discontinuation rates remained high, highlighting the need for thorough pre-treatment counseling on expected mild, transient symptoms and strategies to mitigate nausea. Future prospective studies are needed to assess long-term outcomes and identify patient characteristics associated with greater treatment success, to better individualize GLP-1-based therapy in adolescent obesity.