Multifrequency bioelectric impedance measurements for predicting body water compartments in duchenne muscular dystrophy.

Body hydration and extra- to intra-cellular water ratio (ECW: ICW) have been studied in 12 duchenne muscular dystrophy (DMD) patients and 15 healthy controls. Subjects underwent total body water (TBW) and extracellular water (ECW) assessment by deuterium and bromide dilution, respectively. Multifrequency bioelectric impedance analysis (MFBIA) was performed on all subjects with the aim to establish its accuracy in predicting TBW and ECW in DMD. Body hydration was lower (51.8 +/- 2.8 vs 58.5 +/- 5.9%, P < 0.01) and the ECW: ICW ratio higher (1.15 +/- 0.25 vs 0.70 +/- 0.23, P < 0.001) in DMD than in control subjects. Hence, control-generated formulae for predicting TBW and ECW from MFBIA gave inaccurate results in DMD subjects. Population-specific formulae were developed to obtain an accurate prediction of body water compartments in DMD patients.