title: Fluid overload correction and cardiac history influence brain natriuretic peptide evolution in incident haemodialysis patients.
abstract: OBJECTIVE
  Brain natriuretic peptide (BNP) is a cardiac peptide secreted by ventricle myocardial cells under stretch constraint. Increased BNP has been shown associated with increased mortality in end-stage renal disease patients. In patients starting haemodialysis (HD), both fluid overload and cardiac history are frequently present and may be responsible for a high BNP plasma level. We report in this study the evolution of BNP levels in incident HD patients, its relationship with fluid removal and cardiac history as well as its prognostic value.
  
  
  METHODS
  Forty-six patients (female/male: 21/25; 68.6 ± 14.5 years old) surviving at least 6 months after HD treatment onset were retrospectively analysed. Plasma BNP (Chemoluminescent Microparticule ImmunoAssay on i8200 Architect Abbott, Paris, France; normal value < 100 pg/mL) was assessed at HD start and during the second quarter of HD treatment (Q2).
  
  
  RESULTS
  At dialysis start, the plasma BNP level was 1041 ± 1178 pg/mL (range: 14-4181 pg/mL). It was correlated with age (P = 0.0017) and was significantly higher in males (P = 0.0017) and in patients with cardiac disease history (P = 0.001). The plasma BNP level at baseline was not related to the mortality risk. At Q2, predialysis systolic blood pressure (BP) decreased from 140.5 ± 24.5 to 129.4 ± 20.6 mmHg (P = 0.0001) and the postdialysis body weight by 7.6 ± 8.4% (P < 0.0001). The BNP level decreased to 631 ± 707 pg/mL (P = 0.01) at Q2. Its variation was significantly correlated with systolic BP decrease (P = 0.006). A high BNP level was found associated with an increased risk of mortality.
  
  
  CONCLUSIONS
  Hence, plasma BNP levels decreased during the first months of HD treatment during the dry weight quest. Whereas initial BNP values were not associated with increased mortality risk, the BNP level at Q2 was independently predictive of mortality. Hence, BNP is a useful tool to follow patient dehydration after dialysis start. Initial fluid overload may act as a confounding factor for its value as a prognostic marker because of cardiac disease.
authors.affiliation: NephroCare, Tassin, France. chchazot@gmail.com
authors.forename: Charles
authors.initials: C
authors.lastname: Chazot
authors.forename: Cyril
authors.initials: C
authors.lastname: Vo-Van
authors.forename: Eric
authors.initials: E
authors.lastname: Zaoui
authors.forename: Thierry
authors.initials: T
authors.lastname: Vanel
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Hurot
authors.forename: Christie
authors.initials: C
authors.lastname: Lorriaux
authors.forename: Brice
authors.initials: B
authors.lastname: Mayor
authors.forename: Patrick
authors.initials: P
authors.lastname: Deleaval
authors.forename: Guillaume
authors.initials: G
authors.lastname: Jean
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism*; D005260:Female; D005440:Fluid Therapy / Q000009:adverse effects*; D005500:Follow-Up Studies; D005602:France; D005919:Glomerular Filtration Rate; D006331:Heart Diseases / Q000150:complications*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000209:etiology / Q000628:therapy*; D007677:Kidney Function Tests; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011379:Prognosis; D006435:Renal Dialysis; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain