Inflammatory biomarkers and the prediction of coronary events among people at intermediate risk: the EPIC-Norfolk prospective population study

Objective: To evaluate the role of the inflammatory biomarkers C-reactive protein (CRP), myeloperoxidase, paraoxonase, secretory phospholipase A2 group IIA (sPLA2), lipoprotein-associated phospholipase A2, fibrinogen, macrophage chemoattractant protein-1 and adiponectin, in predicting the risk of coronary heart disease (CHD) among people estimated to be at intermediate risk according to the Framingham Risk Score (FRS). Design: Prospective case-control study nested in EPIC-Norfolk cohort. Setting: Norfolk, UK. Patients: Apparently healthy men and women aged 4579 years. Main outcome measures: Risk of future coronary artery disease. Results: For participants predicted to be at intermediate risk by the FRS, the highest c statistics were observed for FRS plus CRP (0.61, 95% CI 0.57 to 0.65) and for FRS plus sPLA2 (0.56, 95% CI 0.52 to 0.6). Net correct reclassification of cases and controls for each marker was assessed for people across the entire risk spectrum and again for people at intermediate risk only. The largest differences were observed for CRP, 12.0% net reclassification improvement in the entire risk spectrum and 28.4% net reclassification improvement in the intermediate-risk group and for sPLA2, the net reclassification improvement was 6.4% in the entire risk spectrum and 16.3% in the intermediate-risk group. Conclusions: The discriminatory potential of inflammatory biomarkers was substantially different when analysed across the entire risk spectrum compared with the subgroup of people at intermediate risk.