title: The Association between Bone Density at Os Calcis and Body Composition in Healthy Children Aged 9-12 Years.
abstract: OBJECTIVE
  This cross-sectional study aimed to quantify the relationship between the bone mineral density at the os calcis and the body mass composition in healthy children.
  
  
  METHODS
  The areal bone mineral density was measured at the os calcis with peripheral dual energy X-ray absorptiometry. The fat free mass, fat mass and percentage fat mass were measured using bioelectric impedance, in 237 Korean children, aged 9 to 12 years. The sexual maturity was determined by self assessment, using standardized series of the 5 Tanner stage drawings, accompanied by explanatory text.
  
  
  RESULTS
  From multiple linear regression models, adjusted for age, sexual maturity and height, the fat free mass was found to be the best predictor of the calcaneal bone mineral density in both sexes. About 15 and 20% variabilities were found in the calcaneal bone mineral densities of the boys and girls, respectively, which can be explained by the fat free mass. After weight adjustment, the percentage fat mass was negatively associated with the calcaneal bone mineral density in both sexes.
  
  
  CONCLUSIONS
  The findings of this study suggest that the fat free mass, among the body compositions, is the major determinant of bone mineral density at the os calcis in Korean children aged 9 to 12 years. Obesity, defined as the percentage fat mass, is assumed to have a negative effect on the calcaneal bone density in children of the same weight.
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Shin
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: Ki Suk
authors.initials: KS
authors.lastname: Kim
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: Hee Young
authors.initials: HY
authors.lastname: Kim
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: In Sook
authors.initials: IS
authors.lastname: Lee
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: Hyo Jee
authors.initials: HJ
authors.lastname: Joung
authors.affiliation: School of public health, Seoul National University, Korea.
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Cho
keywords: Body composition; Bone density; Calcaneus; Obesity; Sex Maturation