EXTRA- TO INTRACELLULAR FLUID RATIO IN NORMOHYDRATED AND OVERHYDRATED SUBJECTS

Abstract

Bioimpedance analysis is a potential technique to measure fluid distributions in the body. A method of whole body bioimpedance (WBIA) based dry weight estimation for dialysis patients is shown, which accounts for the individual nutrition and training status of each patient. Extracellular and intracellular fluid volumes (ECF and ICF) of healthy controls (n=34, age 25–44 y) were measured with a multifrequency WBIA analyzer (4200, XITRON Technologies Inc.). ECF/ICF was variable, but correlated with the deviation of measured TBW from TBW according to the Watson equation. Hereby the deviation of bioimpedance based TBW and Watson-TBW is affected by the individual nutrition and training status. After establishing this correlation for healthy individuals, the ECF/ICF ratio of chronic hemodialysis patients (n=31, age 31–82 y) was measured and compared to the curve of the healthy population. Pre-dialysis patients who were considered clinically overhydrated showed higher ECF/ICF ratios than healthy controls with comparable nutrition and training status. Conclusion: For dry weight assessment by use of bioimpedance analysis it is essential to account for the individual nutrition and training status of each patient.