C-reactive protein, interleukin-6, and fibrinogen as predictors of coronary heart disease: The PRIME study

Abstract

Objective - This study was undertaken to examine the association of plasma inflammatory markers such as C-reactive protein (CRP), interleukin-6, and fibrinogen with the incidence of coronary heart disease within the prospective cohort study on myocardial infarction (PRIME study). Methods and Results - Multiple risk factors were recorded at baseline in 9758 men aged 50 to 59 years who were free of coronary heart disease (CHD) on entry. Nested case-control comparisons were carried out on 317 participants who suffered myocardial infarction (MI)-coronary death (n = 163) or angina (n = 158) as an initial CHD event during a follow-up for 5 years. After adjustment for traditional risk factors, incident MI-coronary death, but not angina, was significantly associated with CRP, interleukin-6, and fibrinogen, but only interleukin-6 remained significantly associated with MI-coronary death when the 3 inflammatory markers were included in the model. The different interleukin-6 levels in Northern Ireland and France partly explained the difference in risk between these countries. Interleukin-6 appeared as a risk marker of MI-coronary death, and it improved the definition of CHD risk beyond LDL cholesterol. Conclusions - This association may reflect the underlying inflammatory reaction located in the atherosclerotic plaque or a genetic susceptibility on the part of CHD subjects to answer a proinflammatory stimulus and subsequent increase in hepatic CRP gene expression.