title: Development and validation of a new dry weight estimation method using single frequency bioimpedance in hemodialysis patients.
abstract: BACKGROUND
  We proposed a new method to estimate dry weight (DW) using single frequency bioimpedance.
  
  
  METHODS
  We hypothesized that the change in whole body resistance at 50 kHz (R(50)) was proportional to the ultrafiltration volume (UFV) during a hemodialysis (HD) session. When the targeted resistance estimated in healthy subjects was reached, the patient achieved his/her DW. UFV and R(50) were monitored in 40 HD patients. Another 43 HD patients were stratified into 2 groups to validate this method.
  
  
  RESULTS
  The change in whole body resistance was proportional to UFV in each of the 40 HD patients. In the DW(decrease) group, pre-dialysis systolic blood pressure (n = 29, 154.5 ± 22.8 vs. 146.9 ± 22.3, p < 0.05) and antihypertensive medicine (4.7 ± 3.6 vs. 3.3 ± 2.2, p < 0.05) decreased without adverse symptoms change. In the DW(increase) group, the number of adverse symptoms in 1 week (n = 14, 26 vs. 6, p < 0.05) decreased without a change in systolic blood pressure.
  
  
  CONCLUSIONS
  This method may become a convenient and cheaper way to estimate DW in HD patients.
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, and Key Laboratory of Renal Disease, Ministry of Health of China, Beijing.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Dou
authors.forename: Xuyang
authors.initials: X
authors.lastname: Cheng
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.forename: Xiafeng
authors.initials: X
authors.lastname: Bai
authors.forename: Leiyun
authors.initials: L
authors.lastname: Wu
authors.forename: Weiya
authors.initials: W
authors.lastname: Guo
authors.forename: Xinju
authors.initials: X
authors.lastname: Zhao
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Liyun
authors.initials: L
authors.lastname: Cao
authors.forename: Li
authors.initials: L
authors.lastname: Zuo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition; D001835:Body Weight; D017097:Electric Impedance; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis / Q000379:methods*; D015203:Reproducibility of Results; D055815:Young Adult