Background and aims: The increased iron level and the labile iron pool (LIP) in circulating monocytes are connected to a higher frequency of cardiovascular events. Methods: The study investigates the relationship between LIP in circulating monocytes and markers of iron metabolism and atherosclerosis (inflammation, oxidative stress, endothelial dysfunction and arterial elasticity) in long-term blood donors and non-donor volunteers.
Results: We found that donors had significantly higher LIP values than the control group (1.89 +- 0.47 μM vs. 1.50 +- 0.41 μM, p = 0.007). Despite the observed tendency for the donor group to have higher blood pressure, cholesterol, glucose and HOMAR-IR (homeostasis model assessment of insulin resistance), the groups did not differ in inflammatory markers, markers of endothelial dysfunction and markers of impaired arterial elasticity.
The donor group had significant changes in iron metabolism (higher serum Fe, ceruloplasmin, and TfR/Ft ratio (transferrin receptor/ferritin ratio) and lower hepcidin, ferritin, and CD163), indicating depletion of body iron stores and activation of iron turnover. Conclusions: LIP seems to be a good marker of iron turnover activity in these individuals despite the lack of a decrease in the hemoglobin concentration.
We did not find a significant correlation between LIP levels and atherosclerosis progression in the two groups. However, further studies are needed to assess long-term donorship as a protective factor against atherosclerosis.