title: Vasoactive Peptide Levels after Change of Dialysis Mode.
abstract: OBJECTIVE
  Plasma concentrations of the N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) are increased in end-stage renal disease. Improvement in hemodynamic stability has been reported when switching from hemodialysis (HD) to on-line hemodiafiltration (ol-HDF). The aim of this study was to investigate plasma concentrations of NT-proBNP, BNP and neuropeptide Y (NPY) during a 1-year follow-up, after a change from high-flux HD to postdilution ol-HDF. Additional variables were also studied, e.g. pulse wave velocity and ordinary clinical parameters.
  
  
  METHODS
  We conducted a prospective, single-center study including 35 patients who were switched from HD to HDF. Plasma concentrations of NT-proBNP, BNP and NPY before and after dialysis were measured at baseline (i.e. HD) and at 1, 2, 4, 6 and 12 months on HDF.
  
  
  RESULTS
  All three peptide levels decreased significantly during HD and HDF when comparing concentrations before and after dialysis. Mean absolute value (before/after) and relative decrease (%) before versus after dialysis was 13.697/9.497 ng/l (31%) for NT-proBNP, 62/40 ng/ml (35%) for BNP and 664/364 pg/l (45%) for NPY. No significant differences were observed when comparing predialysis values over time. However, postdialysis NT-proBNP concentration showed a significant decrease of 48% over time after the switch to HDF.
  
  
  CONCLUSIONS
  The postdialysis plasma levels of NT-proBNP, BNP and NPY decreased significantly during both dialysis modes when compared to before dialysis. The postdialysis lowering of NT-proBNP increased further over time after the switch to ol-HDF; the predialysis levels were unchanged, suggesting no effect on its production in the ventricles of the heart.
authors.affiliation: Department of Nephrology, Region Östergötland, Linköping, Sweden ; Department of Medical and Health Sciences, Linköping University, Linköping, Sweden ; Department of Biomedical Engineering, Technomedicum, Tallinn University of Technology, Tallinn, Estonia.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Uhlin
authors.affiliation: Department of Clinical Pharmacology, Karolinska University Hospital Huddinge, Stockholm, Sweden.
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Odar-Cederlöf
authors.affiliation: Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden ; Department of Clinical Chemistry, Center for Diagnostics, County Council of Östergötland, Linköping, Sweden.
authors.forename: Elvar
authors.initials: E
authors.lastname: Theodorsson
authors.affiliation: Department of Nephrology, Region Östergötland, Linköping, Sweden ; Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Fernström
keywords: Convective therapies; Hemodiafiltration; N-terminal fragment of pro-brain natriuretic peptide; Neuropeptide Y; Vasoactive peptides