Sex- and age-related differences in the prognostic value of C-reactive protein in patients with angiographic coronary artery disease.
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.
Khor
Lillian L C
LL
Department of Internal Medicine, University of Utah, Salt Lake City, Utah, USA.
Muhlestein
Joseph B
JB
Carlquist
John F
JF
Horne
Benjamin D
BD
Bair
Tami L
TL
Maycock
Chloe A
CA
Anderson
Jeffrey L
JL
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
D002097:C-Reactive Protein