Homocysteine is a sulfur-containing aminoacid produced during methionine metabolism. Since 1969 the relationshipbetween altered homocysteine metabolism and both coronary and peripheral atherotrombosis has been known; inrecent years, experimental evidence has shown that elevated plasma concentrations of homocysteine are associatedwith an increased risk of atherosclerosis and cardiovascular ischemic events. Several mechanisms by which elevatedhomocysteine concentrations impair vascular function have been proposed, including impairment of endothelialfunction, production of reactive oxygen species and consequent oxidation of low-density lipoproteins. Folate and Bvitamins, required for remethylation of homocysteine to methionine, are the most important dietary determinants ofhomocysteinemia and daily supplementation typically lowers plasma homocysteine concentrations. Recently, largescaleintervention trials have been conducted to determine whether lowering homocysteine concentrations through Bvitamins supplementation can decrease cardiovascular risk in healthy subjects or improve survival in patients withcoronary heart disease. Some of these trials found no significant beneficial effects of combined treatment with folateand vitamin B12, with or without vitamin B6, in spite of significant homocysteine lowering. In conclusion, it is still unclearwhether decreasing plasma concentrations of homocysteine through diet or vitamin supplementation may beparalleled by a reduction in cardiovascular risk.
|Numero di pagine||7|
|Stato di pubblicazione||Published - 2010|
All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Medical Laboratory Technology
- Biochemistry, medical