title: Estimation of abdominal fat mass: validity of abdominal bioelectrical impedance analysis and a new model based on anthropometry compared with dual-energy x-ray absorptiometry.
abstract: OBJECTIVE
  Since abdominal adiposity has been associated with increased risk for chronic diseases, valid and low cost methods to estimate it are needed for clinical and research purposes. The aim of the current study was to develop and validate, using dual-energy x-ray absorptiometry (DXA) as reference method, a model that estimates abdominal fat mass percentage (AFM%) in white postmenopausal women based on simple and easy-to-apply anthropometric measurements. An additional aim was to validate an abdominal bioelectrical impedance analyzer (ViScan) for estimating waist circumference (WC) and AFM% in this group.
  
  
  METHODS
  Ninety-one postmenopausal women (mean age, 61.5 y) with body mass index ranging from 20.9 to 42 kg/m2 were randomly divided into one training set (n = 60) and one testing set (n = 31) to develop and validate a model based on anthropometric measurements estimating abdominal fat mass. Furthermore, in all 91 participants, ViScan estimations of WC and AFM% were validated against tape measurement and DXA results.
  
  
  RESULTS
  The model developed was AFM% = 4.496 + (0.318 × WC) + 0.342 × suprailiac skinfold (r = 0.834, P < 0.0001). The model had no significant bias (0.25%) and ± 7.5% limits of agreement. ViScan significantly overestimated WC by 7.04 cm and estimated AFM% with no significant bias (-0.13%) and ± 7.6% limits of agreement.
  
  
  CONCLUSIONS
  Both the model and ViScan are equally valid against DXA in estimating AFM%. However, ViScan is not valid in estimating WC in white postmenopausal women.
authors.affiliation: From the 1Department of Nutrition and Dietetics, Harokopio University, Athens, Greece; and 2Laboratory of Body Composition, Department of Human Nutrition and Dietetics, Technological Educational Institute of Crete, 72 300, Sitia, Greece.
authors.forename: Yannis
authors.initials: Y
authors.lastname: Manios
authors.forename: Spyridon
authors.initials: S
authors.lastname: Kanellakis
authors.forename: George
authors.initials: G
authors.lastname: Moschonis
authors.forename: Ilias
authors.initials: I
authors.lastname: Pipidis
authors.forename: Efstathios
authors.initials: E
authors.lastname: Skoufas
authors.forename: Vassilis
authors.initials: V
authors.lastname: Zafiropulos
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D050154:Adiposity; D000886:Anthropometry / Q000379:methods*; D017097:Electric Impedance; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology*; D008875:Middle Aged; D017698:Postmenopause; D012044:Regression Analysis; D015203:Reproducibility of Results