ESPE Abstracts

Background: Irisin is a myokine involved in the browning of adipocytes, regulation of body composition, and enhancement of glycemic control. Additionally, irisin has been suggested to play a role in the signaling mechanisms associated with activation of the hypothalamic-pituitary-gonadal axis and the onset of puberty. Given the reported relationship between irisin levels and glycemic control, as well as the link between body composition and glycemic control, we hypothesized that there is a relationship between irisin levels and body composition.

Objectives: 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 with type 1 diabetes (48 boys, 24 prepubertal; and 28 girls, 12 prepubertal) with a mean age of 11.7 ± 3.8 years and a mean disease duration of 2.1 ± 1.6 years. Body composition was assessed by bioelectrical impedance analysis (muscle-to-fat ratio 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: Among boys, the first linear regression model found a significant interaction between age and puberty (β= -11.0, SE = 4.2, P = 0.011). Irisin levels increased with age among prepubertal boys, whereas irisin levels declined with age among pubertal boys. The second regression model included age, HbA1c, IDAA1c, creatinine, skeletal muscle mass index and muscle-to-fat ratio z-score; age was the sole significant correlation with irisin levels among pubertal boys (β=-12.5, SE=3.4, P =0.002) but not prepubertal boys. In contrast to boys, there was no significant interaction between puberty and age observed in girls. Furthermore, the second regression model did not reveal any significant association with irisin.

Conclusion: Our preliminary findings highlight sex and age differences in irisin levels among children and adolescents with type 1 diabetes. Further research is needed to clarify the potential role of irisin in metabolic and hormonal processes during different stages of pubertal development in children and adolescents with diabetes.