Abstract: SA-PO850

ECW/TBW Determined by Three Bioimpedance Devices: A Comparative Study in Hemodialysis Patients and Healthy Subjects

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 704 Fluid, Electrolyte, Acid-Base Disorders

Authors

  • Preciado, Priscila, Renal Research Institute, New York, New York, United States
  • Zhu, Fansan, Renal Research Institute, New York, New York, United States
  • Thwin, Ohnmar, Renal Research Institute, New York, New York, United States
  • Tao, Xia, Renal Research Institute, New York, New York, United States
  • Rosales, Laura, Renal Research Institute, New York, New York, United States
  • Raimann, Jochen G., Renal Research Institute, New York, New York, United States
  • Thijssen, Stephan, Renal Research Institute, New York, New York, United States
  • Kotanko, Peter, Renal Research Institute, New York, New York, United States
Background

The ratio of extracellular (ECW) to total body water (TBW) is a widely accepted indicator of fluid status.However,ECW/TBW may differ between bioimpedance devices.We compared three commercially available bioimpedance devices in hemodialysis (HD) patients and health subjects (HS)

Methods

Ten patients (8 males,age 58.1±12 years) and 12 healthy subjects (7 females,age 33.3±5.6 years) were studied using two eight-point bioimpedance devices,InBody 770 (InBody USA,Cerritos,CA),Seca mBCA 514 (Seca North America,Chino,CA) and Hydra 4200 (Xitron Technologies,San Diego,CA).Measurements were performed pre and post HD in patients and once in HS.ECW,intracellular water (ICW),TBW, and ECW/TBW reported by the devices were compared between pre and post HD, and between patients and HS

Results

ECW and ICW were significantly lower in InBody compared to Seca and Hydra (Table 1).Peridialytic changes of ECW (ΔECW), ICW (ΔICW), and TBW (ΔTBW) did not differ.Peridialytic weight loss (ΔWt; 2.58±0.51 kg) did not differ from ΔTBW reported by InBody and Hydra. ΔECW reported by InBody and Hydra was significantly lower than ΔWt.Seca measurements of ΔTBW was higher than ΔWt.In HD patients and HS InBody measurements of ECW/TBW were lower compared to Seca and Hydra,respectively(Fig.1).Pre and post HD ECW/TBW measured with InBody and Hydra did not differ(Fig.2)

Conclusion

This pilot study indicates that ECW/TBW measurements differ between bioimpedance devices.InBody reports significantly lower ECW/TBW values compared to Seca and Hydra

DevicePre HD
ECW (L)
Pre HD
ICW(L)
Pre HD
TBW (L)
ΔECW
(L)
ΔICW
(L)
ΔTBW
(L)
Post HD
ECW/TBW
InBody15.5±2.624.0±4.439.6±6.91.1±0.40.9±0.52.0±0.80.39±0.01
Seca17.7±2.721.0±4.538.7±6.82.3±1.71.5±2.53.8±4.20.44±0.03
Hydra17.5±2.820.0±5.537.5±7.31.5±0.91.1±2.22.6±2.00.45±0.05
p1-2<0.01<0.0001ns0.06nsns<0.0001
p1-3<0.01<0.01nsnsnsns<0.001

p1-2 indicates paired t test between InBody and Seca; p1-3 indicates paired t test between InBody and Hydra.ΔECW, ΔICW and ΔTBW represent the differences between pre HD and post HD