title: Predialysis NTproBNP predicts magnitude of extracellular volume overload in haemodialysis patients.
abstract: BACKGROUND
  Increased natriuretic peptides are associated with increased cardiovascular and all-cause mortality for haemodialysis (HD) patients. However, debate continues whether these biomarkers are increased by extracellular water (ECW) excess and can be used to aid clinical assessment of volume status and help determine target weight.
  
  
  METHODS
  We measured N terminal probrain natriuretic peptide (NT-proBNP) predialysis in 375 stable haemodialysis outpatients with corresponding pre and postdialysis multifrequency bioelectrical impedance assessments (MFBIA) of (ECW)/total body water (TBW).
  
  
  RESULTS
  Median age 64 (51-75), 63.9% male, 42.9% diabetic, 43.2% Caucasoid, 14.4% with a history of myocardial infarction, 8.4% coronary artery bypass surgery, dialysis vintage 28.2 (12.3-55.5) months. Median predialysis NT-proBNP 283 (123-989) pmol/l, and predialysis ECW/TBW ratio 0.397 ± 0.029. On multivariate analysis, predialysis log NT-proBNP was associated with predialysis systolic blood pressure (β 0.007, p = 0.000), weight (β -0.008, p = 0.001), valvular heart disease (β 0.342, p = 0.015, ECW/TBW (β 1.3, p = 0.019) and log CRP (β 0.145, p = 0.037). Dividing patients into NTproBNP quartiles, %ECW/TBW and relative ECW overhydration were significantly greater for the highest quartile vs. lowest (40.5 ± 4.1 vs. 39.0 ± 1.1, and 1.51 ± 1.24 vs. 0.61 ± 0.69 l, respectively, p < 0.001).
  
  
  CONCLUSIONS
  In this study, predialysis NTproBNP values were associated with direct assessments of the extracellular volume excess measured by MFBIA and systolic arterial blood pressure. This suggests that predialysis NTproBNP values can potentially be used to aid clinical assessment of volume status in dialysis patients to determine target weight.
authors.affiliation: Renal Unit, Department of Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Arkom
authors.initials: A
authors.lastname: Nongnuch
authors.forename: Kwanpeemai
authors.initials: K
authors.lastname: Panorchan
authors.forename: Andrew
authors.initials: A
authors.lastname: Davenport
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000737:chemistry; D015415:Biomarkers / Q000097:blood*; D001794:Blood Pressure; D001026:Coronary Artery Bypass; D048909:Diabetes Complications / Q000378:metabolism; D017097:Electric Impedance; D045604:Extracellular Fluid / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000150:complications; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010045:Outpatients; D010446:Peptide Fragments / Q000097:blood*; D012044:Regression Analysis; D006435:Renal Dialysis / Q000379:methods*; D014883:Water-Electrolyte Imbalance / Q000209:etiology
chemical_list: D000959:Antihypertensive Agents; D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain