An elevated level of the amino acid homocysteine in the blood is being heralded as the ‘new cholesterol’ in predicting cardiovascular disease.
It has certainly captured the press’s imagination. UK Health Journalist of the Year Susan Clark wrote a feature extolling the tests virtues, going as far as to say it was 40 times more accurate than cholesterol in predicting heart problems. She also bemoans the fact that despite high levels being treatable with B vitamins and folic acid doctors do not yet offer the test.
Likewise Steve Connor of the Independent reported on the excitement caused by the announcement of a clinical trial of homocysteine at the American Association for the advancement of science meeting in Washington (2000).
The trial is being run in Oregon and aims to demonstrate whether taking dietary supplements of folic acid will be as effective as existing cholesterol lowering efforts. According to Dr Donald Jacobsen of the Cleveland Clinical Foundation the key was having reliable assays:" As a result of this it soon became that homocysteine, as a risk factor would rival cholesterol. In fact, some call homocysteine the new cholesterol.
It was some 25 year ago that Kilmer McCully observed that children born with homocystinuria, an inability to metabolise the amino acid homocysteine and resulting in high urine levels, exhibited gross atherosclerotic lesions of the blood vessel wall. Since then a vast number of clinical studies have confirmed the association of elevated blood levels of homocysteine with increased risk of cardiovascular disease.
The American Heart Association has cautiously endorsed this new risk factor and the US is now fortifying bread and cereals with vitamins known to potentially lower homocysteine. Test methodology has improved to the extent that the assay can now be carried out in hospital laboratory analysers. Bedside versions are under development.
Homocysteine has arrived as a marker of cardiovascular disease. Together with cholesterol and other modern assays, such as for AFT, homocysteine should make up a routine battery of tests used to establish the risk profile of an individual developing CHD. |