title: Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children.
abstract: OBJECTIVE
  To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand.
  
  
  METHODS
  Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8-10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach.
  
  
  RESULTS
  The BIA prediction equation for the estimation of TBW was as follows: TBW=0.231 × height(2)/resistance+0.066 × height+0.188 × weight+0.128 × age+0.500 × sex-0.316 × Thais-4.574 (R (2)=88.0%, root mean square error (RMSE)=1.3 kg), and for the estimation of FFM was as follows: FFM=0.299 × height(2)/resistance+0.086 × height+0.245 × weight+0.260 × age+0.901 × sex-0.415 × ethnicity (Thai ethnicity =1, others = 0)-6.952 (R (2)=88.3%, RMSE=1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category.
  
  
  CONCLUSIONS
  Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.
authors: Department of Student Nutrition, National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, China.
authors: A
authors: A
authors: Liu
authors: N M
authors: NM
authors: Byrne
authors: G
authors: G
authors: Ma
authors: L
authors: L
authors: Nasreddine
authors: T P
authors: TP
authors: Trinidad
authors: K
authors: K
authors: Kijboonchoo
authors: M N
authors: MN
authors: Ismail
authors: M
authors: M
authors: Kagawa
authors: B K
authors: BK
authors: Poh
authors: A P
authors: AP
authors: Hills
mesh_terms: D000886:Anthropometry / Q000379:methods*; D001208:Asia; D044466:Asian People; D001825:Body Fluid Compartments; D015992:Body Mass Index; D001834:Body Water; D002648:Child; D003903:Deuterium; D017097:Electric Impedance; D005006:Ethnicity; D005260:Female; D006801:Humans; D007201:Indicator Dilution Techniques; D008297:Male; D008433:Mathematics; D012044:Regression Analysis; D015203:Reproducibility of Results
chemical_list: D003903:Deuterium