title: Correlation between forearm bone mineral density and body composition in Japanese females aged 18-40 years.
abstract: OBJECTIVE
  The purpose of this study was to clarify the relationship between forearm bone mineral density (BMD), body mass index (BMI), and body composition focusing on body fat percentage (BF%) in Japanese females 18 to 40 years old.
  
  
  METHODS
  Subjects were 2,280 females 18-40 years old. Anthropometric measurements were taken, and a medical history was obtained by questionnaire, including age at the time of the study and age at menarche. BF% was measured by bioelectrical impedance analysis. Forearm BMD was measured using dual-energy X-ray absorptiometry (DXA). The correlations of BMD with BMI and BF% were analyzed using a structural equation model.
  
  
  RESULTS
  The standardized regression coefficients for the path from BMI to BMD and the path from BF% to BMD were 0.538 and -0.184 respectively. The squared multiple correlation of BMD was 0.146. In addition, the standardized regression coefficient for the path from BMI to BF% was 0.896.
  
  
  CONCLUSIONS
  The results showed a positive correlation between BMD and BMI and an inverse correlation between BMD and BF%. At the same time, it was noted that BF% increased with BMI. This indicated that BMD is dependant on BF% in subjects who have a similar BMI. Therefore, this study concluded that it is necessary to take body composition measurements into account when examining the relationship between BMI and BMD, especially in young females.
authors: Department of Fundamental Nursing, School of Health Sciences, Kumamoto University, 4-24-1 Kuhonji, 862-0976, Kumamoto, Japan, arimatsu@hs.kumamoto-u.ac.jp.
authors: Misao
authors: M
authors: Arimatsu
authors: Takao
authors: T
authors: Kitano
authors: Naoko
authors: N
authors: Kitano
authors: Takeaki
authors: T
authors: Inomoto
authors: Masahiro
authors: M
authors: Shono
authors: Makoto
authors: M
authors: Futatsuka