title: Non-cardiac determinants of NT-proBNP levels in the elderly: relevance of haematocrit and hepatic steatosis.
abstract: BACKGROUND
  The levels of B-type natriuretic peptide (BNP), a marker of heart failure, are higher in women and anaemic subjects, and tend to be lower in obese people. These relationships are still largely unexplained and it is unclear whether they also apply to the N-terminal portion of BNP precursor (NT-proBNP).
  
  
  OBJECTIVE
  This cross-sectional study was performed to assess general and abdominal obesity, sex and other variables as possible extra-cardiac determinants of NT-proBNP.
  
  
  RESULTS
  A random sample of 713 subjects aged 65-74 years resident of Pianoro (Northern Italy) underwent assessment of NT-proBNP, several haemato-chemical variables, body mass index (BMI), body fat estimation (through skinfold measurement), waist circumference, intra-abdominal thickness and possible presence of hepatic steatosis (by ultrasound examination). An echocardiogram was performed in a subset of 125 subjects. In multivariable analysis NT-proBNP was inversely associated with haematocrit (r=0.22, P<0.0001) and hepatic steatosis (r=0.13, P=0.0001), while no association was found with BMI and body fat estimation. NT-proBNP was higher in women, but this relationship disappeared when haematocrit was included in the multivariable model. The associations with haematocrit and hepatic steatosis were independent from echocardiographic measurements.
  
  
  CONCLUSIONS
  NT-proBNP is increased in subjects with low haematocrit, which explains the higher values in women. Although NT-proBNP is not affected by general adiposity, low levels of NT-proBNP are associated with hepatic steatosis.
authors.affiliation: Department of Internal Medicine, Cardioangiology, Hepatology, University of Bologna, S. Orsola-Malpighi Hospital, Via Albertoni, 15, 40138 Bologna, Italy. amuscari@med.unibo.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Muscari
authors.forename: Annalisa
authors.initials: A
authors.lastname: Berzigotti
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Bianchi
authors.forename: Claudia
authors.initials: C
authors.lastname: Giannoni
authors.forename: Amedeo
authors.initials: A
authors.lastname: Ligabue
authors.forename: Donatella
authors.initials: D
authors.lastname: Magalotti
authors.forename: Dario
authors.initials: D
authors.lastname: Sbano
authors.forename: Annalisa
authors.initials: A
authors.lastname: Zacchini
authors.forename: Marco
authors.initials: M
authors.lastname: Zoli
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood; D005234:Fatty Liver / Q000097:blood* / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006400:Hematocrit; D006801:Humans; D006973:Hypertension / Q000097:blood; D008297:Male; D015999:Multivariate Analysis; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009765:Obesity / Q000097:blood* / Q000503:physiopathology; D010446:Peptide Fragments / Q000097:blood*; D018570:Risk Assessment; D012737:Sex Factors; D012907:Smoking / Q000097:blood
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain