Age and sex dependency of the biochemical indices of bone remodelling

The values for the bone isoenzyme of serum alkaline phosphatase peak in the first two years of age, between 6 and 7 years of age, before the end of puberty and in the postmenopause. A population between the ages of 29 and 45 provides a reference population to which all other age groupings can be compared. A significant positive correlation was found between bone isoenzyme of serum alkaline phosphatase and urinary hydroxyproline excretion in children as well as after puberty. However, in the children the urinary hydroxyproline excretion was significantly higher when compared with the bone isoenzyme of alkaline phosphatase. A significant positive correlation was found between the bone isoenzyme of alkaline phosphatase and plasma tartrate-resistant acid phosphatase, irrespective of age and sex. The biochemical indices of bone remodelling correlated significantly with the growth rate in children and adolescents. The results are in good agreement with the concept of the coupling of bone formation to bone resorption.