title: Sex- and age-related differences in the prognostic value of C-reactive protein in patients with angiographic coronary artery disease.
abstract: OBJECTIVE
  To determine whether sex and age affect serum C-reactive protein level and its prognostic value in patients with coronary artery disease.
  
  
  METHODS
  In a consecutive series of 2254 patients with angiographically defined coronary artery disease, baseline C-reactive protein and predictive value for incident death or nonfatal myocardial infarction by sex and age (<55 and > or =55 years) were compared. C-reactive protein levels were measured by fluorescence polarization immunoassay with use of a medium-sensitivity method. Patients were followed for a mean (+/-SD) of 3.1 +/- 2.2 years. Comparisons used ln-transformed C-reactive protein and linear and time-to-event regression analyses, adjusting for confounders.
  
  
  RESULTS
  Overall, women had higher geometric mean C-reactive protein levels than did men (1.47 vs. 1.30 mg/dL, P <0.001), even after adjustment for age, hyperlipidemia, diabetes, prior myocardial infarction, body mass index, and heart failure (P = 0.002). High C-reactive protein levels were associated with increased mortality or myocardial infarction among men (adjusted hazard ratio [HR] = 1.9; 95% confidence interval [CI]: 1.5 to 2.3) but not among women (HR = 1.0; 95% CI: 0.69 to 1.4). Among patients aged <55 years, C-reactive protein level was similarly predictive in men and women (HR = 2.2 vs. 2.7), whereas in patients > or =55 years of age, it remained predictive for men (HR = 1.8; 95% CI: 1.5 to 2.3) but not women (HR = 0.93; 95% CI: 0.63 to 1.4).
  
  
  CONCLUSIONS
  We found that the prognostic value of C-reactive protein in coronary artery disease patients varied by sex and age. This sex-age interaction may have important implications for C-reactive protein-based secondary risk assessment and requires further investigation.
authors.affiliation: Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
authors.forename: Lillian L C
authors.initials: LL
authors.lastname: Khor
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Muhlestein
authors.forename: John F
authors.initials: JF
authors.lastname: Carlquist
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Horne
authors.forename: Tami L
authors.initials: TL
authors.lastname: Bair
authors.forename: Chloe A
authors.initials: CA
authors.lastname: Maycock
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Anderson
mesh_terms: D000367:Age Factors; D000368:Aged; D002097:C-Reactive Protein / Q000032:analysis*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000097:blood* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012307:Risk Factors; D012737:Sex Factors
chemical_list: D002097:C-Reactive Protein