title: Comparison of Near-Infrared Spectroscopy and Bioelectrical Impedance Analysis for the Assessment of Body Composition in the Frail Elderly.
abstract: BACKGROUND
  Body composition is an important component of health related fitness. Near-infrared spectroscopy (NIRS) is a non-invasive, simple and rapid method of assessing body fat percentage. However, it is unknown whether NIRS can accurately estimate FFM in community-dwelling frail elderly.
  
  
  OBJECTIVE
  This study aimed to compare NIRS with bioelectrical impedance analysis (BIA) in FFM measurement.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Shizuoka, Japan.
  
  
  METHODS
  The study population comprised 53 community-dwelling frail elderly (15 men, 38 women; mean age 84.8±6.4 years; body mass index 19.7±3.5 kg/m2).
  
  
  METHODS
  FFM and percentage fat mass (%FM) were estimated using a NIRS device at two sites (biceps and calf) and compared to body composition measured by BIA. Simple linear regression and Bland-Altman analyses were used to determine agreement between the methods.
  
  
  RESULTS
  FFM determined by BIA highly correlated with that determined by NIRS at both the biceps and calf (r=0.92 for both; p<0.001). The correlation coefficients for %FM estimated by NIRS were slightly lower (r=0.70 for biceps; r=0.66 for calf). In NIRS assessments, systematic biases were found for %FM but not for FFM.
  
  
  CONCLUSIONS
  NIRS has significant potential for body composition analysis. Further comparative and longitudinal studies need to be conducted using an agreed reference analysis method to find a simple and more suitable method that can be applied among the community-dwelling frail elderly.
authors.affiliation: Tomohiko Kamo, 3453 Mikatahara-machi, Kitaku, Hamamatsu-shi, Shizuoka, Japan. Tel: +81-090-7682-1192, e-mail:12dr01@g.seirei.ac.jp.
authors.forename: T
authors.initials: T
authors.lastname: Kamo
authors.forename: H
authors.initials: H
authors.lastname: Ishii
authors.forename: D
authors.initials: D
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Iwagaya
authors.forename: T
authors.initials: T
authors.lastname: Ishida
authors.forename: Y
authors.initials: Y
authors.lastname: Nishida