Objective: Ferritin concentrations are often increased in patients with metabolic syndrome and type 2 diabetes mellitus, but few reports have examined the associations between ferritin and atherosclerosis. We investigated whether any relationship between ferritin and coronary artery calcium score (CACS) >0 (as a marker of atherosclerosis) was independent of potential confounders, such as iron-binding capacity (transferrin), low-grade inflammation, and cardiovascular risk factors.
Methods and results: Data were analyzed from a South Korean occupational cohort of 12 033 men who underwent a cardiac computed tomography estimation of CACS and measurements of multiple cardiovascular risk factors. One-thousand three- hundred-fifteen of 12 033 (11.2%) subjects had a CACS >0. For people with a CACS >0, median (interquartile range) ferritin concentration was 196.8 (136.3-291.9) compared with 182.2 (128.1-253.6) in people with a CACS=0; P<0.001. In the highest ferritin quartile, 14.7% (442/3008) of subjects had a CACS >0 compared with 9.7% (292/3010) in the lowest quartile (P<0.0001). With increasing ferritin quartiles, there were also higher proportions of people with diabetes mellitus (P<0.0001), hypertension (P<0.0001), coronary heart disease (P=0.003), and a Framingham Risk Score >10% (P<0.0001). In logistic regression modeling with CACS >0 as the outcome, ferritin but not transferrin was independently associated with CACS >0 (odds ratio for highest quartile versus lowest quartile, 1.66 [95% CI, 1.3-1.98]; P=0.0001).
Conclusions: Increased ferritin concentrations are associated with the presence of a marker of early coronary artery atherosclerosis, independently of traditional cardiovascular risk factors including Framingham risk score, transferrin, preexisting vascular disease, diabetes mellitus, metabolic syndrome factors, and low-grade inflammation.