title: Body-density measurement in children: the BOD POD versus Hydrodensitometry.
abstract: OBJECTIVE
  To compare estimates of body density (Db) from air-displacement plethysmography (ADP) with measured and predicted thoracic-gas-volume (TGV) measurements and those from hydrodensitometry (HD) in children.
  
  
  METHODS
  Seventeen participants (13 male and 4 female; 10.1 ± 2.20 yr, 42.0 ± 15.03 kg, 145.6 ± 17.41 cm, 30.0 ± 8.66 kg/m²) were tested using ADP and HD, with ADP always preceding HD. Db estimates were compared between ADP with measured TGV, ADP with predicted TGV, and the reference measure, HD. Regression analyses were used to assess the accuracy of the ADP methods, and potential bias between the ADP procedures and HD were evaluated using Bland-Altman analyses. The cross-validation criteria described by Lohman for estimating Db relative to HD were used to interpret the results of the study.
  
  
  RESULTS
  A significant difference was found between Db estimates from ADP with measured TGV (1.0453 ± 0.01934 g/cm³) and ADP with predicted TGV (1.0415 ± 0.01858 g/cm³); however, neither was significantly different from Db obtained by the reference HD procedure (1.0417 ± 0.02391 g/cm³). For both ADP procedures, regression analyses produced an r = .737-.738, r² = .543-.544, and SEE = 0.02 g/cm³, and the regression lines deviated significantly from the line of identity; however, no significant biases were indicated.
  
  
  CONCLUSIONS
  Despite no significant mean differences between Db estimates from the ADP procedures and HD, more cross-validation research is needed before recommending the BOD POD for routine use with children in clinical and research settings.
authors: Dept. of Sport and Exercise Science, Barry University, Miami Shores, FL, USA.
authors: Jason C
authors: JC
authors: Holmes
authors: Ann L
authors: AL
authors: Gibson
authors: J Gualberto
authors: JG
authors: Cremades
authors: Constance M
authors: CM
authors: Mier
mesh_terms: D000704:Analysis of Variance; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D003720:Densitometry / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D010993:Plethysmography, Whole Body / Q000295:instrumentation* / Q000379:methods*; D012044:Regression Analysis; D015203:Reproducibility of Results