Eur J Clin Invest 2011; 41 (8): 846–853
Background The aim of our study was to assess the impact of increased iron stores on the presence of asymptomatic atherosclerosis in a cohort of healthy men. We anticipated that higher iron stores would be associated with higher soluble cluster of differentiation 163 (sCD163) concentrations, elevated markers of oxidative stress, inflammation and higher common carotid intima-media thickness, independently of traditional risk factors of atherosclerosis.
Methods In this cross-sectional study that included 72 healthy men, we measured the ultrasonography of common carotid intima-media thickness (IACC), the ratio of plasma-circulating transferrin receptors concentration to plasma ferritin concentration, certain inflammatory and oxidative stress markers, insulin sensitivity, plasma lipids and markers of endothelial dysfunction.
Results The plasma-circulating transferrin receptor concentration to plasma ferritin concentration ratio (TfR/F) showed significant association with IACC (r = −0·310, P = 0·008 vs. r = 0·295, P = 0·012). Multivariate analysis confirmed that the correlation of TfR/F with IACC is independent of traditional risk factors of atherosclerosis. The TfR/F ratio correlated with other indicators of atherosclerotic process fibrinogen (r = −0·292, P = 0·013), von Willebrand factor (vWf; r = 0·284, P = 0·017), sCD163 (r = 0·239, P = 0·043) and IL-8 (r = 0·233, P = 0·049). In multivariate analysis, TfR/F independently correlated with haemoglobin (β = −0·220, P = 0·047), fibrinogen (β = −0·290, P = 0·009), IL-8 (β = 0·227, P = 0·039) and sCD163 (β = 0·244, P = 0·025); however, when vWf was added, significant independent correlation was seen only with fibrinogen (β = −0·301, P = 0·007) and IL-8 (β = 0·219, P = 0·047). In addition, we demonstrated the independent correlation of sCD163 with vWf (β = 0·240, P = 0·040).
Conclusions Our study showed a clear association of body iron stores expressed by the TfR/F ratio with asymptomatic carotid atherosclerosis. TfR/F further exhibited an independent positive correlation with fibrinogen and a negative correlation with sCD163 and IL-8.