Hyperhomocysteinemia, considered "the cholesterol of nineties", is an established risk factor for cardiovascular diseases and premature atherosclerosis. Hyperhomocysteinemia is due to genetic and acquired factors (unhealthy lifestyle with poor diet in folate and vitamin B, elderly, renal impairment, thyroid diseases, malignancies). More recently, hyperhomocysteinemia was associated with venous thrombosis. Several studies found a correlation with a usual site of thrombosis (central retinal vein, mesenterical level, cerebral veins, Budd-Chiari syndrome). Other studies showed the association between hyperhomocysteinemia and recurrent venous thrombosis. This condition is of high interest because homocysteine may represent a potentially reversible cause of thrombophilia. Although methylenetetrahydrofolate reductase (MTHFR) C677T genotype and deficits of folic acid, vitamin B12 lead to hyperhomocysteinemia, in cases with a thrombotic event the correlations between homocysteine level and folic acid as well as between homocysteinemia and vitamin B12 were found to be weak and no significant correlation between homocysteinemia and MTHFR was identified. Recently, some authors reported an independent association between low levels of folic acid or vitamin B12 and venous thrombosis. Regarding the MTHFR genotype, the risk for venous thrombosis is increased only in patients with factor V Leiden. A recent meta-analysis of 24 retrospective and 3 prospective studies published in electronic literature showed that a 5 micromol/L higher homocysteine level was associated with a 27

作者：Cristina, Ho?oleanu；M, Porojan-Iuga；M L, Rusu；A, Andercou

来源：Romanian journal of internal medicine = Revue roumaine de medecine interne 2007 年 45卷 2期