title: Bilirubin and coronary heart disease risk in the Prospective Epidemiological Study of Myocardial Infarction (PRIME).
abstract: BACKGROUND
  Classic coronary heart disease risk factors fail to explain the large coronary heart disease incidence gradient between Northern Ireland and France. The Prospective Epidemiological Study of Myocardial Infarction (PRIME), a multicentre prospective study of 10593 men, aims to investigate novel risk factors in these populations. We tested the hypothesis that higher bilirubin, a bile pigment possessing antioxidant properties, is associated with decreased coronary heart disease risk.
  
  
  METHODS
  Bilirubin was measured in 216 participants who had developed coronary heart disease at 5-year follow-up and in 434 matched controls.
  
  
  RESULTS
  Bilirubin was significantly lower in cases (geometric mean 7.95 micromol/l; interquartile range 5.32-12.33 micromol/l) compared with controls (9.07; 6.16-12.76; P=0.005). Conditional logistic regression, adjusted for classical and putative risk factors, showed a U-shaped pattern, with coronary heart disease risk significantly lower for bilirubin in the third and fourth fifths, compared with the first. Additionally, there was a significant quadratic relationship between coronary heart disease risk and fifths of bilirubin concentration (chi2=6.80, df=2; P=0.035).
  
  
  CONCLUSIONS
  These findings suggest that bilirubin is a novel coronary heart disease risk marker in middle-aged men, with a U-shaped relationship observed between bilirubin concentration and coronary heart disease risk.
authors.affiliation: Faculty of Medicine, Queen's University Belfast, Northern Ireland, UK.
authors.forename: Judith A
authors.initials: JA
authors.lastname: Troughton
authors.forename: Jayne V
authors.initials: JV
authors.lastname: Woodside
authors.forename: Ian S
authors.initials: IS
authors.lastname: Young
authors.forename: Dominique
authors.initials: D
authors.lastname: Arveiler
authors.forename: Philippe
authors.initials: P
authors.lastname: Amouyel
authors.forename: Jean
authors.initials: J
authors.lastname: Ferrières
authors.forename: Pierre
authors.initials: P
authors.lastname: Ducimetière
authors.forename: Chris C
authors.initials: CC
authors.lastname: Patterson
authors.forename: Frank
authors.initials: F
authors.lastname: Kee
authors.forename: John W G
authors.initials: JW
authors.lastname: Yarnell
authors.forename: Alun
authors.initials: A
authors.lastname: Evans
mesh_terms: D001663:Bilirubin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D003327:Coronary Disease / Q000097:blood* / Q000453:epidemiology*; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D007494:Ireland; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000453:epidemiology*; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D001663:Bilirubin