Iron and atherosclerosis.

Iron is a vital element in life. However, it may participate in diverse pathological processes by catalyzing the formation of reactive oxygen free radicals. During the past decade, considerable evidence has supported the role of oxidative stress in the development of atherosclerosis and related cardiovascular diseases. The oxidation of low-density lipoprotein (LDL) and lipid is believed to be one of the crucial events leading to plaque formation in vasculature. It has been hypothesized that iron-mediated oxidation is involved in this process. In favor of this idea, several epidemiological studies have shown that the level of body iron stores is positively correlated with the incidence of coronary heart disease in human populations. However, some studies have yielded conflicting results. Recently, studies conducted in our laboratory and others have demonstrated that iron deposition is prominent in human atherosclerotic lesions. The iron deposits appear to colocalize with ceroid, which is an end product of extensively oxidized lipid and protein complex, in lesions, providing histological evidence to support the iron hypothesis. Additional experiments in animals have further revealed that the severity of atherosclerosis can be markedly influenced by iron overload or deficiency. Collectively, these data provide a strong pathological basis to support the detrimental role of iron in vascular damage and progression of the disease.