Hyperhomocysteinemia: Risk factor for development of occlusive vascular diseases

Occlusive vascular diseases take the first places on lists of diseases in general population today. In spite of this, all risk factors which contribute to development of these diseases are not yet known. Recent studies have shown that homocysteine plays a critical role in it and is established as a new risk factor. WHAT IS HOMOCYSTEINE?: Homocysteine is a sulfur containing amino acid formed in the metabolism of methionine. Reference values of homocysteine in circulation and different forms in plasma are described. HYPERHOMOCYSTEINEMIA--A RISK FACTOR: Homocysteine was associated with atherosclerosis and occlusive vascular disease in 1960s for the first time. Since then, many studies--prospective and retrospective, have confirmed the role of hyperhomocysteinemia as a risk factor in 42% of patients with cerebrovascular disease, 28% with peripheral vascular and 30% with coronary artery disease. The Physician's Health Study, a prospective study in which 15,000 male physicians took part, revealed that increase in homocysteine concentration of 1.7 mumol/l above normal values was associated by threefold higher risk for myocardial infarction. The risk for carotid artery stenosis also increases with elevation of homocysteine concentration. Hyperhomocysteinemia is associated with poor prognosis in patients with angiographically established coronary disease. Stroke, venous thromboembolism, and atherosclerosis in chronic renal failure are some of the complications of hyperhomocysteinemia.