The association of serum irisin with anthropometric, metabolic, and bone parameters in obese children and adolescents

Background Irisin is an adipomyokine secreted by muscle and adipose cells, and it plays a role in glucose, fat, and bone metabolism. This study aimed to determine the correlation of serum irisin levels with anthropometric, metabolic, and bone parameters in obese children and adolescents. Methods:This single-center study included 103 Korean children andadolescents: 54 (52.4%) obese participants with a body mass index (BMI)>= 95thpercentile and 49 (47.6%) healthy controls with BMI within the 15th to 85thpercentile. Various parameters were measured, including fasting blood glucose,fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR),triglyceride and glucose (TyG) index, lipid profile, alkaline phosphatase (ALP),osteocalcin, and 25(OH)-Vitamin D levels. Bone mineral density (BMD) wasmeasured using dual-energy X-ray absorptiometry (DEXA) in 33 healthy subjects. Results: Serum irisin was significantly higher in the obese group than in the control group (mean 18.1 +/- 3.5 vs. 16.2 +/- 2.0 ng/mL;p= 0.001). Serum irisin level was positively correlated with chronological age (r= 0.28;p= 0.004), height SDS(r= 0.24;p= 0.02), BMI SDS (r= 0.37;p< 0. 001), fasting glucose (r= 0.27;p=0.007), fasting insulin (r=0.23;p= 0.03), HOMA-IR (r= 0.21;p= 0.04),osteocalcin (r=0.27;p= 0.006) and negatively correlated with HDL cholesterol (r= -0.29;p= 0.005). All these correlations were evident in obese subjects but not in healthy subjects. ALP and 25(OH)-Vitamin D were unrelated to irisin levels. Among 33 healthy subjects, total body-less head (TBLH) BMD Z-score was positively correlated with serum irisin (r= 0.39;p= 0.03), osteocalcin(r= 0.40;p= 0.02), fasting insulin (r= 0.39;p= 0.04), and HOMA-IR (r= 0.38;p= 0.047). Conclusion This study demonstrated an association between irisin levels and glucose, lipid, and bone parameters in children and adolescents. Our findings suggest that irisin has a potential role in metabolic disorders and bone health in obese children and adolescents.