Selenium as a risk factor for cardiovascular diseases.

Selenium is a powerful antioxidant regulating the activity of the glutathione peroxidase enzymes, which catalyse the detoxification of hydrogen peroxide and organic hydroperoxides. Selenium deficiency has been implicated in the aetiopathogeny of Keshan disease, an endemic cardiomyopathy observed in China, and in other cases of congestive cardiomyopathy in subjects on artificial nutrition. However, the evidence from case-control and prospective studies for an association between low selenium status and cardiovascular diseases remains controversial. Mechanisms whereby selenium protects against such diseases include increased resistance of low-density lipoproteins against oxidative modification, modulation of prostaglandin synthesis and platelet aggregation, and protection against toxic heavy metals. The therapeutic benefit of selenium administration in the prevention and treatment of cardiovascular diseases still remains insufficiently documented.