Serum markers of collagen metabolism and serum osteocalcin in relation to pubertal development in 57 boys at 14 years of age.

We investigated whether levels of serum collagen markers and serum osteocalcin are related to pubertal growth and development in a cross-sectional study of 57 healthy boys at 14 y of age. The level of the soft tissue marker, serum amino-terminal propeptide of type III procollagen (PIIINP) was higher in boys at Tanner stages G3 versus G2 (p < 0.01). The levels of the markers of bone collagen matrix differed only at a more advanced pubertal stage: the formation markers, carboxy-terminal and amino-terminal propeptides of type I procollagen, and the degradation marker, carboxy-terminal telopeptide of type I collagen were higher only at stage G4 versus G3 (p < 0.01). The marker of bone mineralization, serum osteocalcin was also higher only at stage G4 versus G3 (p < 0.01). Stage G4 was associated with the pubertal growth spurt. The results demonstrate that pubertal development should be taken into account when serum levels of collagen markers and osteocalcin are evaluated, and suggest that an increase in serum PIINP in boys at G3 might predict a normal pubertal growth spurt, but the finding remains to be confirmed in longitudinal studies.