title: N‑terminal pro‑B-type natriuretic peptide as a marker of hypervolemia and predictor of increased mortality in patients on hemodialysis.
abstract: BACKGROUND
  N‑terminal pro‑B‑type natriuretic peptide (NT‑proBNP) is an established biomarker of heart failure in the general population. However, its diagnostic value is unclear in hemodialysis (HD) patients owing to renal insufficiency.
  
  
  OBJECTIVE
  The aim of the study was to establish the usefulness of NT‑proBNP for hydration assessment and the relation of NT‑proBNP to the nutritional state and prognosis of survival.
  
  
  METHODS
  In 321 HD patients (206 men; mean age, 65.1 ±21.4 years), we assessed NT‑proBNP levels, overhydration (OHBIA), and the indices of the nutritional state (using a bioimpedance analysis [BIA]) in relation to cardiac troponin T (cTnT), hemoglobin, albumin, total cholesterol (TC), and C‑reactive protein (CRP) levels. The efficacy of HD was assessed using Kt/V, weekly HD dose, and HD session ultrafiltration. The cohort was divided into NT‑proBNP quartiles. Patients with 2 NT‑proBNP measurements were categorized also into change‑over‑time subgroups. A follow‑up lasted for a median period of 23.8 ±26.3 months.
  
  
  RESULTS
  Relative OHBIA increased across the NT‑proBNP quartiles (Q1/Q2/Q3/Q4, 1.31% ±2.56%/2.06% ±2.35%/2.92% ±2.97%/4.62% ±4.22%; P <0.0001). NT‑proBNP was also closely associated with other OH parameters. In addition, there was a significant correlation between NT‑proBNP and cTnT (r = 0.55; P <0.0001). Body mass index (BMI) and fat tissue index (FTI) decreased across the quartiles (BMI, 28.5 ±7.7/26.0 ±6.6/25.8 ±5.4/23.7 ±5.5 kg/m2; FTI, 14.4 ±9.0/14.1 ±7.3/12.3 ±6.8/11.6 ±6.1; P <0.001). The highest albumin level was present in Q1 (4.10 ±0.63/3.99 ±0.51/3.90 ±0.62/3.97 ±0.78 g/dl; P = 0.006). The TC level was the lowest in Q4 (190 ±60/169 ±56/173 ±51/153 ±56 mg/dl; P = 0.002). The hemoglobin level decreased across the quartiles (11.44 ±1.25/11.15 ±2.50/10.79 ±1.51/10.45 ±1.67 g/dl; P = 0.0006). The differences in CRP levels and HD‑related parameters were nonsignificant. During the follow‑up, 97 deaths were recorded (11/26/21/39, P <0.0001).
  
  
  CONCLUSIONS
  NT‑proBNP seems to be a useful biomarker of hypervolemia in HD patients. Nevertheless, it has to be interpreted with regard to the patient's individual residual renal function and cardiovascular status.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Schwermer
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Hoppe
authors.forename: Dorota
authors.initials: D
authors.lastname: Radziszewska
authors.forename: Patrycja
authors.initials: P
authors.lastname: Kłysz
authors.forename: Peter
authors.initials: P
authors.lastname: Sawatiuk
authors.forename: Justin
authors.initials: J
authors.lastname: Nealis
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kałużna
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kaczmarek
authors.forename: Ewa
authors.initials: E
authors.lastname: Baum
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Pawlaczyk
authors.forename: Andrzej
authors.initials: A
authors.lastname: Oko
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001810:Blood Volume; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain; D010446:Peptide Fragments; D006435:Renal Dialysis / Q000401:mortality*
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain