Homocysteine is an intermediate product in the methionine metabolism, which is catalysed by several enzymes with
B2, B6, B12 vitamins and folic acid as cofactors. Moderate hyperhomocysteinemia, defined as total homocysteine
concentration between 12 to 30 µmol/l, represents an independent risk factor for heart disease, vascular brain disease,
phlebothrombosis and thromboembolic complications. It is related to placental abruptions, spina bifida and some
neuropsychiatric disorders. Hyperhomocysteinemia is a metabolic syndrome based on interaction between genetic
factors (most frequently 677C/T polymorphism of methylentetrahydrofolate reductase), diseases and demographic
factors (smoking, aging, hormonal and nutritional factors). Moderate hyperhomocysteinemia occurs in about 20 to
30 % of patients with clinical complications of atherosclerosis. Prospective and genetic studies have shown, that
moderate hyperhomocysteinemia in healthy persons is only a weak predictor of cardiovascular diseases. Contrary
to it, in patients with ischaemic heart disease, renal failure or diabetes mellitus and in thromboembolic disease,
hyperhomocysteinemia represents a strong predictor of vascular morbidity and mortality. Toxic effects of hyperhomocysteinemia
on the vascular wall can be explained by a chemical modification of lipoproteins and vascular
structure, oxidative stress, endothelial dysfunction, inadequate endothelial cell regeneration, smooth muscle cell
proliferation or by an accumulation of functionally non sufficient connective tissue. Also thrombogenic effects or
an increased expression of cholesterol level controlling proteins and fatty acids in the liver can be considered.
Treatment of hyperhomocysteinemia is based on the administration of pharmacological doses of folic acid, B6 and
B12 vitamines, which can decrease total homocysteine concentration by 25 to 30 %. Such decrease, which is in
average 3 µmol/l, results in the decrease of relative risk of ischaemic heart disease by 11 to 16 %, phlebothrombose
by 25 % and vascular brain diseases by 19 to 24 %.
homocysteine, hyperhomocysteinemia, risk of cardiovascular diseases, pharmoconutrition, B2, B6, B12
vitamins, folic acid.