title: Bioimpedance-guided fluid management in maintenance hemodialysis: a pilot randomized controlled trial.
abstract: BACKGROUND
  Chronic subclinical volume overload happens very frequently in hemodialysis patients and is associated directly with hypertension, increased arterial stiffness, left ventricular hypertrophy, and ultimately higher mortality.
  
  
  METHODS
  Randomized controlled parallel-group trial.
  
  
  METHODS
  131 patients from one hemodialysis center, randomly assigned into 2 groups.
  
  
  METHODS
  Dry weight prescription using results derived from repeated 3-month bioimpedance measurements to guide ultrafiltration for strict volume control (bioimpedance group; n=62) compared with clinical judgment without bioimpedance measures (clinical-methods group; n=69) for 2.5 years.
  
  
  RESULTS
  The primary outcome was all-cause mortality over 2.5 years (the duration of the intervention). Secondary outcomes were change in relative arterial stiffness, fluid overload, and blood pressure (BP) over 2.5 years.
  
  
  METHODS
  Bioimpedance measurements were performed using a Body Composition Monitor device. Pulse wave velocity analysis was performed at baseline, 2.5 years (end of intervention), and 3.5 years (end of study). Relative fluid overload and BP were assessed at 3-month intervals.
  
  
  RESULTS
  The unadjusted HR for all-cause death in the bioimpedance group (vs the clinical-methods group) was 0.100 (95% CI, 0.013-0.805; P=0.03). After 2.5 years, we found a greater decline in arterial stiffness, relative fluid overload, and systolic BP in the bioimpedance group than the clinical-methods group. Between-group differences in change from baseline to the end of intervention were -2.78 (95% CI, -3.75 to 1.80)m/s for pulse wave velocity (P<0.001), -2.99% (95% CI, -5.00% to -0.89%) for relative fluid overload (P=0.05), and -2.43 (95% CI, -7.70 to 2.84)mmHg for systolic BP (P=0.4).
  
  
  CONCLUSIONS
  Echocardiography was not performed as cardiovascular assessment and the caregivers were not masked to the intervention.
  
  
  CONCLUSIONS
  Our study showed improvement in both surrogate and hard end points after strict volume control using bioimpedance to guide dry weight adjustment. These findings need to be confirmed in a larger trial.
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania. Electronic address: onomihai@yahoo.com.
authors.forename: Mihai
authors.initials: M
authors.lastname: Onofriescu
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania.
authors.forename: Simona
authors.initials: S
authors.lastname: Hogas
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania.
authors.forename: Luminita
authors.initials: L
authors.lastname: Voroneanu
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania.
authors.forename: Mugurel
authors.initials: M
authors.lastname: Apetrii
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania.
authors.forename: Ionut
authors.initials: I
authors.lastname: Nistor
authors.affiliation: Department of Medicine, Division of Nephrology, Istanbul Medeniyet University School of Medicine, Istanbul, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kanbay
authors.affiliation: Nephrology Department, "Dr. C.I. Parhon" University Hospital, University of Medicine and Pharmacy "Gr. T. Popa," Iasi, Romania.
authors.forename: Adrian C
authors.initials: AC
authors.lastname: Covic
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology; D017097:Electric Impedance / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000517:prevention & control; D017379:Hypertrophy, Left Ventricular / Q000453:epidemiology / Q000517:prevention & control; D007676:Kidney Failure, Chronic / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D063177:Pulse Wave Analysis; D006435:Renal Dialysis; D012307:Risk Factors; D016896:Treatment Outcome; D059289:Vascular Stiffness / Q000502:physiology; D014882:Water-Electrolyte Balance / Q000502:physiology*
keywords: Bioimpedance; hemodialysis; pulse wave velocity; survival