| Abstract: | Siconolfi, Steven F., Randal J. Gretebeck, William W. Wong,Robert A. Pietrzyk, and Sheril S. Suire. Assessing total body andextracellular water from bioelectrical response spectroscopy. J. Appl. Physiol. 82(2): 704-710, 1997. We developed and validated assessments for total body water(TBW) and extracellular water (ECW) by using two resistance values of anew electric circuit model (CM) (two resistors: a capacitor and aninductor) with or without body mass. Fluid shifts occurring after 40 min of supine rest did not decrease the validity of either estimate. CMestimates were valid; r = 0.941 to0.969, low SE of estimates of 1.15-2.28 kg, nonsignificant meandifferences (CM  dilution; % = 0.4 to 1.3%) thatwere close to the expected measurement errors for TBW (±1%) andECW (±5%), and Bland-Altman pairwise comparisons that showedequivalence between methods. The CM estimates of TBW and ECW hadmarginally better validity than the previously published bioimpedancemodels. The advantage of the CM model is its assessments of multiplefluid spaces and that it does not require gender-specific equations. Weconclude that CM estimate of TBW is acceptable, whereas furthervalidation is needed before the ECW estimate should be used in aclinical or research setting. |
