CLINICAL CHEMISTRY, Vol. 41, No.1,1995 173 Plasma Homocyst(e)ine and Arterial Occlusive Diseases: A Mini-Review

Homocysteine (HCY), which is derived from the intracel-lular metabolism of methionine, is exported into plasma, where it circulates mostly in oxidized forms (i.e., homo-cystine and cysteine-HCY disulfide) and mainly bound to proteins. Concentrations of total HCY, or homocyst(e)ine [H(e)], are increased in 15-40 % of patients with coronary, cerebral, or peripheral arterial diseases. Such association of H(e) with arterial occlusive diseases has been docu-mented in retrospective, cross-sectional, and prospective studies. Concentrations of H(e) are also increased in sub-jects having thickened carotid arteries, as determined by ultrasonography, and who are asymptomatic for athero-sclerosis. Statistical analyses of data from several series of patients demonstrate that H(e) concentrations are as-sociated with coronary artery disease, independently fro