Homocysteine--relevant for atherogenesis?

Abstract

Numerous studies report strong associations between hyperhomocysteinemia and premature atherosclerotic vascular disease. Causes of hyperhomocysteinemia are hereditary heterozygous or, in very rare cases, homozygous defects, and quite frequently a lack of the coenzymes B6 and B12 and the cosubstrate folate. Lifestyle factors, age, sex, acute and chronic illness, vitamin deficiency and certain drugs may elevate homocysteine concentrations. Vitamin B supplementation, especially folic acid, is an effective treatment of hyperhomocysteinemia. Clinical trials are required to confirm the potential benefit of lowering homocysteine in regard of the development and progression of atherosclerotic vascular disease. The relevance of hyperhomocysteinemia as a risk factor for atherosclerosis, in contrast to the classical triad of risk factors, namely hypercholesterolemia, smoking and hypertension, is still unknown. Furthermore, a lack of standardized analytical methods for the determination of both homocysteine and blood folate renders the evaluation of studies and clinical data difficult. Therefore, at present, diagnosis and treatment is only recommended in high-risk patients (strong family history of premature atherosclerosis or arterial occlusive disease, especially in the absence of other risk factors, as well as in members of their families) with hyperhomocysteinemia.