The characteristics of bone turnover in the second decade in relation to age and puberty development in healthy Japanese male and female subjects - Japanese Population-based Osteoporosis Study

Background : There are few studies that clarify the characteristics of bone turnover in children and adolescents. Furthermore, little has been published on changes in urinary CrossLaps(TM) (CTx) in Japanese subjects. Aim : To investigate biochemical markers of bone turnover in subjects, in relation to age and puberty development. Subjects and methods : We measured serum bone specific alkaline phosphatase (B-Alp) and CTx in 1207 Japanese subjects aged 9 18 years. As an indicator of puberty development, the age that pubic hair appeared in males and menstruation started in females was obtained from questionnaires. Results : B-Alp and CTx/Cr ( creatinine) had high values before and just after the indicators and was lower thereafter, reaching a plateau in both genders. There was no significant difference in these values in males 5-6 years, or 7 years and more after the appearance of pubic hair. B-Alp and CTx/Cr values 7 years and more after menarche were significantly lower than those 5-6 years after menarche, however the differences were relatively small. Conclusions : Subjects in the second decade can be divided into three groups: before the appearance of pubic hair for males and menarche for females, up to and including 3 4 years after them and 5-6 years and more after them'.