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

•This study examines the possible role of osteocalcin on adiposity-related factors in boys during pubertal development.•Increase in osteocalcin was associated with the increase in testosterone in boys during pubertal development.•Increase in osteocalcin was associated with the increase in insulin only in normal weight boys during pubertal development.