title: Impact of hemoglobin on plasma pro-B-type natriuretic peptide concentrations in the general population.
abstract: BACKGROUND
  Age, sex, and renal function contribute to variations in plasma concentrations of B-type natriuretic peptide (BNP) and its molecular precursor (proBNP). Recent studies indicate that anemia may also affect proBNP concentrations in patients with heart failure or stroke. However, the impact of hemoglobin status on proBNP concentrations has not been established in the general population.
  
  
  METHODS
  In the 4th examination in the Copenhagen City Heart Study, we performed a nested case-control study of 6238 individuals from a Danish general population. Of these, 3497 randomly selected participants also underwent an echocardiographic examination. The population was stratified into groups depending on health and hemoglobin status. Correlations between hemoglobin and proBNP concentrations were examined by simple and multiple regression analyses, adjusted for variables known to influence the proBNP plasma concentration.
  
  
  RESULTS
  The mean proBNP concentration was increased 1.7-fold in the group with anemia vs the nonanemic group [mean (SD) 42 (45) pmol/L vs 25 (29) pmol/L, P <0.0001, n = 5892]. Multiple regression analysis confirmed an independent effect of hemoglobin on proBNP concentrations. In a selected subgroup without signs or symptoms of heart disease (n = 2855), lower hemoglobin concentrations, defined as <120 g/L in women and <130 g/L in men, were associated with increased circulating proBNP concentrations, but the contribution to the overall variation in proBNP concentrations was modest.
  
  
  CONCLUSIONS
  Because moderate anemia is associated with a 1.7-fold increase in proBNP concentrations, hemoglobin concentrations should be taken into consideration in patients with nonspecific symptoms of heart disease and increased proBNP concentrations.
authors.affiliation: Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Nybo
authors.forename: Marianne
authors.initials: M
authors.lastname: Benn
authors.forename: Rasmus
authors.initials: R
authors.lastname: Mogelvang
authors.forename: Jan Skov
authors.initials: JS
authors.lastname: Jensen
authors.forename: Peter
authors.initials: P
authors.lastname: Schnohr
authors.forename: Jens F
authors.initials: JF
authors.lastname: Rehfeld
authors.forename: Jens Peter
authors.initials: JP
authors.lastname: Goetze
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006454:Hemoglobins; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010949:Plasma; D011498:Protein Precursors / Q000097:blood*; D012016:Reference Values; D012044:Regression Analysis; D016277:Ventricular Function, Left
chemical_list: D006454:Hemoglobins; D011498:Protein Precursors; D020097:Natriuretic Peptide, Brain