title: 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.
abstract: 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.
  
  
  OBJECTIVE
  To investigate biochemical markers of bone turnover in subjects, in relation to age and puberty development.
  
  
  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'.
authors.affiliation: Department of Welfare Promotion and Epidemiology, School of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsukura
authors.forename: S
authors.initials: S
authors.lastname: Kagamimori
authors.forename: H
authors.initials: H
authors.lastname: Nishino
authors.forename: T
authors.initials: T
authors.lastname: Yamagami
authors.forename: M
authors.initials: M
authors.lastname: Iki
authors.forename: E
authors.initials: E
authors.lastname: Kajita
authors.forename: Y
authors.initials: Y
authors.lastname: Kagawa
authors.forename: H
authors.initials: H
authors.lastname: Yoneshima
authors.forename: T
authors.initials: T
authors.lastname: Matsuzaki
authors.forename: F
authors.initials: F
authors.lastname: Marumo
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001842:Bone and Bones / Q000378:metabolism*; D002648:Child; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D010024:Osteoporosis / Q000378:metabolism; D011627:Puberty / Q000502:physiology*