Influence of Sex and Age on Irisin Levels in Pediatric Type 1 Diabetes: A Pilot Study

Background: Irisin is a myokine involved in the browning of adipocytes, the regulation of body composition and the enhancement of glycemic control. Additionally, irisin has been suggested to play a role in signaling mechanisms associated with the onset of puberty. In this study, we aimed to explore the interaction between muscle and adipose indices, urine irisin levels and glycemic control. Methods: This cross-sectional pilot study enrolled 76 consecutive pediatric patients (mean age 11.7 ± 3.8 years) diagnosed with type 1 diabetes (mean disease duration 2.1 ± 1.6 years). Body composition was assessed by bioelectrical impedance analysis (MFR z-score and skeletal muscle mass index). Urine irisin levels and glycemic control parameters (HbA1c, insulin dose-adjusted A1c [IDAA1c]) were evaluated. One linear regression model, stratified by sex, analyzed the sex-specific impact of puberty and age on irisin levels. A second linear regression model explored the associations of selected variables with irisin levels. Results: The first linear regression model revealed that irisin levels rise with age in prepubertal boys and decline with increased age among pubertal boys. The second linear regression analysis revealed no significant associations between irisin levels and metabolic parameters after adjusting for covariates. In contrast to boys, there were no significant interactions found in girls. Conclusions: Our novel findings revealed sex and age differences in the irisin levels of children and adolescents with type 1 diabetes. The dynamics underlying the role of irisin during pubertal development in the pediatric population with diabetes warrant further exploration.