Application of Multi-frequency Bioelectrical Impedance Analysis for Body Water Evaluation in Hemodialysis Patients

Jang, Jae Young; Cho, Seong; Jang, Ho Sick; Kim, Sung Hun; Park, Jee Eun; Song, Chun Young; Kim, Sung Rok

Abstract

BACKGROUND
It is necessary to measure total body water (TBW) in evaluation of the hemodialysis adequacy. Waston's equation has been used clinically. And it is important to measure adequate dry body weight to avoid fluid overloading after hemodialysis. But there was no objective method to measure dry body weight, it was estimated subjectively by clinicians (doctors and nurses). Multi-frequency bioelectrical impedance analysis (MFBIA) has emerged as a clinical tool of the measurement of total body water (TBW) and body fluid compartment (ICW, ECW). The purpose of this study is to investigate the correlation MFBIA-TBW and Watson equation, Then intracellular water (ICW)/extracellular water (ECW) ratio (I/E ratio) usefulness in the evaluation of dry body weight. METHODS: 20 HD patients treated 3 times/week and 21 sex and age adjusted normal control subjects were studied. We measuerd and compared MFBIA-TBW to Waston equation, estimate reproducibility MFBIA-TBW measurement. Then MFBIA-ECW, ICW and I/E ratio were measured and compared dialysis patients both pre- and post dialysis to control group. RESULTS: The correlation between Wastron-TBW and MFBIA-TBW for patients was 0.948 (p<0.001). The closeness of agreement between MFBIA-TBW and Waston-TBW is shown Bland-Altman plots. There was no difference in post-dialysis patient's ICW/ECW ratio compared to control group. CONCLUSION: MFBIA is useful tool for dialysis patients' TBW measurements. Also ICW/ECW ratio measurement by MFBIA may be used to estimate the adequate ultrafiltration.