title: B-type natriuretic peptide is not a volume marker among patients on hemodialysis.
abstract: BACKGROUND
  Although the cardiac biomarker B-type natriuretic peptide (BNP) is strongly related to mortality in end-stage renal disease (ESRD), whether it is a predictor of weight change or blood pressure (BP) response upon probing dry weight among hypertensive hemodialysis patients remains unknown. The purpose of this study was to examine among people with hypertension on hemodialysis whether BNP is a biomarker of excess volume.
  
  
  METHODS
  Hypertensive hemodialysis patients (n = 150) were randomized to a control group (n = 50) or an ultrafiltration group (n = 100) and followed up for 30 dialysis treatments. After a baseline run-in of six treatments, those assigned to the ultrafiltration group had dry weight probed over 8 weeks. Forty-four-hour interdialytic ambulatory BP and predialysis BNP were measured at the end of run-in period, at 4 weeks and at 8 weeks.
  
  
  RESULTS
  The median BNP concentration was 93 pg/mL (interquartile range 31-257 pg/mL). The magnitude of decline in the BNP depended on the baseline concentration of BNP, but did not require probing dry weight or weight loss. No relationship existed between decline in postdialysis weight upon probing dry weight and baseline BNP. Furthermore, reduction in the BNP was not required for decline in postdialysis weight. Predialysis log BNP modestly predicted ambulatory systolic and pulse pressure independently of other risk factors. No relationship was found between decline in BP upon probing dry weight and baseline BNP. Upon probing dry weight, reduction in BNP was not required for decline in systolic ambulatory BP.
  
  
  CONCLUSIONS
  Taken together, these data suggest that among hypertensive patients on hemodialysis BNP is not a volume marker.
authors.affiliation: Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center, Indianapolis, IN, USA.
authors.forename: Rajiv
authors.initials: R
authors.lastname: Agarwal
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D018660:Blood Pressure Monitoring, Ambulatory; D001810:Blood Volume; D001835:Body Weight; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D006435:Renal Dialysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain
keywords: BNP; ESRD; dry weight; hemodialysis; hypertension