title: [Study of normal reference values for bone mineral contents in children and adolescents in Beijing].
abstract: OBJECTIVE
  The paper aims to provide reference values of bone mineral content for school-age children and adolescents in Beijing.
  
  
  METHODS
  Normal values for total body bone mineral content (TBMC) were derived from measurements on 1025 children and adolescents aged from 6 to 18 years in Beijing city, and bone mineral content (BMC) values for selected regions of interest were also presented, including head, chest, midriff, pelvis, legs and arms. Both BMC and body mineral density were determined by dual-energy x-ray absorptiometry (DEXA).
  
  
  RESULTS
  The results revealed that bone mineralization increased gradually in early childhood and accelerated during adolescence and there were significant age and gender effects on all regions of interest as well as total body. TBMC in 18 year group was about 3 and 2.7 times more respectively for male and female than that in 6 year group, and female's increasing trend flat at the age of 14, while male TBMC keep growing until 17. Legs contribute much more to the increase of TBMC than other regions. Compared with white-origin children, the subjects were bestowed with more TBMC but less TBMD.
  
  
  CONCLUSIONS
  BMC depends on sex, age, region and race. The normal values can be used to the assessment of bone status for children and adolescences to serve clinical as well as research purposes.
authors.affiliation: Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Fengying
authors.initials: F
authors.lastname: Zhai
authors.forename: Liwei
authors.initials: L
authors.lastname: Zhang
authors.forename: Chuanxian
authors.initials: C
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Pan
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000367:Age Factors; D044466:Asian People; D015519:Bone Density; D002648:Child; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012494:Sampling Studies; D012737:Sex Factors