Association of ferritin and lipids with C-reactive protein

C-reactive protein (CRP) and lipids (e.g., low-density lipoprotein [LDL]) are both markers of cardiovascular disease risk, yet they are not highly correlated. Oxidative stress of lipids induced by iron may play a role in vascular inflammation, as indicated by CRP. The purpose of this study was to examine, in a representative sample of United States adults, the relation between ferritin, lipids, and CRP. We analyzed data on adults (aged ≥25 years) in the National Health and Nutrition Examination Survey III, a national public-use data set collected between 1988 and 1994. Ferritin, total cholesterol, LDL, high-density lipoprotein, and ferritin-lipid combinations were analyzed in relation to CRP in age-, gender-, and race-adjusted models as well as models with other potential confounding variables. In adjusted models, neither elevated ferritin (odds ratio [OR] 1.11, 95% confidence interval [CI] 0.94 to 1.32) nor elevated LDL was significantly associated with elevated CRP (OR 1.03, 95% CI 0.79 to 1.33). Patients with elevated ferritin and elevated LDL were more likely to have elevated CRP (OR 1.68; 95% CI 1.06 to 2.68). Patients with elevated ferritin and low high-density lipoprotein were also more likely to have elevated CRP (OR 1.71; 95% CI 1.28 to 2.27). These results suggest that both iron and lipids induce inflammation. Future research needs to focus on preventive medicine to decrease iron in patients with elevated lipids.