Iron and cardiovascular diseases.

Iron is a necessary element for life; however, excess iron leads to oxidative stress by the Fenton reaction. Iron deficiency is prevalent in patients with heart failure, while iron overload is associated in the pathogenesis of atherosclerosis. These findings suggest the "iron paradox" in cardiovascular diseases. Iron metabolism in cardiovascular diseases is complex, and the mechanisms regulating systemic and cellular iron metabolism in cardiovascular diseases remain completely unknown. In this review, we focus on the role of iron in cardiovascular diseases.