Abstract
For more than 30 years, mild to moderate hyperhomocysteinaemia either fasting or after methionine loading have been placed by some authors to independent risks of atherosclerotic vascular disease. The methionine-loading test consistes in the peroral administration of 100 mg of methionine (precursor of homocysteine) per kilogram.
The plasma total homocysteine is measured before and 4-8 hours after ingestion of methionine. No significant adverse effects of the methionine administration was described yet.
A normal range of fasting homocysteine and concentration after a methionine-loading test is defined by an arbitrary cut-off in the distribution of concentrations found in the normal population and depends on age and sex. It is recomended to measure homocysteine levels after a methionine-loading test in high-risk patients with normal basal homocysteine levels.
If the prospective studies confirm the causality between atherosclerosis and homocysteine will be the measurement of fasting homocysteine and homocysteine after a standardised methionine-loading test an unprententious test for determination of non-conventional vascular risk.