PREDICTING BODY CELL MASS WITH BIOIMPEDANCE BY USING THEORETICAL METHODS - A TECHNOLOGICAL REVIEW

The body cell mass (BCM), defined as intracellular water (ICW), was es timated in 73 healthy men and women by total body potassium (TBK) and by bioimpedance spectroscopy (BIS). In 14 other subjects, extracellula r water (ECW) and total body water (TBW) were measured by bromide dilu tion and deuterium oxide dilution, respectively. For all subjects, imp edance spectral data were fit to the Cole model, and ECW and ICW volum es were predicted by using model electrical resistance terms R-E and R -I in an equation derived from Hanai mixture theory, respectively. The BIS ECW prediction bromide dilution was r = 0.91, standard error of t he estimate (SEE) 0.90 liter. The BIS TBW prediction of deuterium spac e was r = 0.95, SEE 1.33 liters. The BIS ICW prediction of the dilutio n-determined ICW was r = 0.87, SEE 1.69 Liters. The BIS ICW prediction of the TBK-determined ICW for the 73 subjects was r = 0.85, SEE = 2.2 2 liters. These results add further support to the validity of the Han ai theory, the equation used, and the conclusion that ECW and ICW volu me can be predicted by an approach based solely on fundamental princip les.