C-Reactive Protein Reportedly a Moderate Predictor for Coronary Heart Disease
C-reactive protein appears to have a lower odds ratio for coronary heart disease than previously reported, but when combined with other circulating markers of inflammation, seems sufficiently stable over time to serve as a predictor of coronary heart disease according to findings from a large prospective cohort study and an updated meta-analysis.
“We found that the decade-to-decade consistency of values for C-reactive protein, the erythrocyte sedimentation rate, and von Willebrand factor is similar to that of values for blood pressure and total serum cholesterol concentration,” writes John Danesh, MB, ChB, DPhil, University of Cambridge, United Kingdom, and colleagues.
The investigators used paired C-reactive protein samples, obtained 12 years apart on average, from 379 of the participants from The Reykjavik Study to determine that C-reactive protein had long-term within-person stability similar to that of blood pressure and total serum cholesterol.
They also assessed the predictive value of C-reactive protein in serum collected from 2,459 patients who died of coronary heart disease or had nonfatal myocardial infarction during a mean follow up of 17.5 years compared with values from 3,969 controls without coronary heart disease who had serum samples available from participation in The Reykjavik Study. They compared these values with values of erythrocyte sedimentation rate and von Willebrand factor also identified in The Reykjavik Study.
After adjusting for smoking status, other established coronary risk factors, and socioeconomic status, the odds ratio for coronary heart disease was 1.45 among patients with C-reactive protein values in the top third – cutoff value of 2.0 mg/L – compared with the bottom third – cutoff value of 0.78 mg/L – of baseline concentrations.
A similar comparison for erythrocyte sedimentation rate – cutoff value of 10 mm and 4 mm in first hour of measurement, respectively, for the top and bottom third – showed an odds ratio of 1.30. A likewise comparison for von Willebrand factor – cutoff value of 124 IU and 88 IU/dL, respectively, for the top and bottom third – showed an odds ratio of 1.11.
By comparison, the odds ratios for coronary heart disease for increased total cholesterol concentration and cigarette smoking were 2.35 and 1.87, respectively.
An updated meta-analysis, of 22 prospective studies involving 7,068 patients, produced similar overall findings.
The authors conclude, “These findings suggest that recent recommendations regarding the use of measurements of C-reactive protein in the prediction of coronary heart disease may need to be reviewed.”
N Engl J Med 2004;350:1387-97.
