Longitudinal changes in bone-testis axis and their associations with insulin resistance in 11- to 12-year-old boys

Abstract Purpose Associations between osteocalcin (OCN), an osteoblast-specific hormone, and different markers of energy metabolism and insulin resistance have been reported in adults, but few studies have investigated this in children. The aim of the current study was to investigate serum OCN levels during pubertal development in normal weight (NW) and overweight (OW) boys, and to evaluate possible associations of OCN with body composition, testosterone, insulin resistance and adipocytokine values during puberty. Methods Ninety 11- to 12-year-old boys were investigated at 12-month intervals over the next 2 years. Boys were divided by their BMI into NW (n = 60) and OW (n = 30) groups. Serum OCN, testosterone, leptin, adiponectin, insulin, HOMA-IR score, and body composition were measured. Results Pubertal development over the 2-year period was similar in both groups. Serum OCN was not different at the beginning of the study and increased similarly in both groups. However, at the end of the study, NW had higher OCN than OW (142.9 ± 5.2 vs. 124.0 ± 7.4 ng/ml; p  Conclusion Serum OCN concentration increases in puberty and the increment is positively associated with the rise in testosterone level in both NW and OW boys. The positive association between the rise in OCN and insulin in NW boys would suggest that OCN may have a role in the development of insulin resistance.