title: Comparison of segmental multifrequency bioelectrical impedance analysis with dual-energy X-ray absorptiometry for the assessment of body composition in a community-dwelling older population.
abstract: OBJECTIVE
  The purpose of the present study was to examine the agreement of segmental multifrequency bioelectrical impedance analysis (SMF-BIA) for the assessment of whole-body and appendicular fat mass (FM) and lean soft tissue mass (LSTM) compared with dual-energy X-ray absorptiometry (DXA) in a community-dwelling Japanese older population.
  
  
  METHODS
  The study population included 551 community-dwelling Japanese older adults (241 men and 310 women) aged between 65 and 87 years. Agreement between SMF-BIA and DXA for whole-body and appendicular body composition was assessed using simple linear regression and Bland-Altman analysis.
  
  
  RESULTS
  High coefficients of determination (R(2)) were observed for whole-body FM (R(2) = 0.91, standard error of estimate [SEE] = 1.4 kg in men and R(2) = 0.94, SEE = 1.2 kg in women) between SMF-BIA and DXA. The R(2) coefficient for whole-body LSTM was higher in men (R(2) = 0.88, SEE = 1.9 kg) than in women (R(2) = 0.83, SEE = 1.5 kg). There was systematic bias with overestimation of whole-body FM and underestimation of whole-body LSTM by SMF-BIA. Proportional bias was noted for measurement of whole-body FM and LSTM in both men and women, but there was no proportional bias between the two methods for measurement of appendicular LSTM (r = 0.05, P = 0.428 and r = -0.10, P = 0.070 for men and women, respectively).
  
  
  CONCLUSIONS
  SMF-BIA is a good alternative for estimating the whole-body and appendicular FM and LSTM in a community-dwelling Japanese older population, although it overestimated FM and underestimated LSTM when validated against DXA.
authors.affiliation: Research Team for Promoting Independence of the Elderly, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Miji
authors.initials: M
authors.lastname: Kim
authors.affiliation: Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Shinkai
authors.affiliation: Research Team for Social Participation and Community Health, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murayama
authors.affiliation: Department of Internal Medicine, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
authors.forename: Seijiro
authors.initials: S
authors.lastname: Mori
mesh_terms: D015502:Absorptiometry, Photon; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D015331:Cohort Studies; D017097:Electric Impedance; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D057187:Independent Living; D007564:Japan; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology; D011446:Prospective Studies; D012111:Residence Characteristics; D018570:Risk Assessment; D055948:Sarcopenia / Q000175:diagnosis / Q000453:epidemiology; D012680:Sensitivity and Specificity; D012737:Sex Factors
keywords: bioelectrical impedance analysis; body composition; dual-energy X-ray absorptiometry; obesity; older adults; sarcopenia