Homocysteine

Increased blood levels as a risk factor for vascular diseases

Physiology and pathophysiology
Homocysteine is a sulphur-containing amino acid not found in food. The role of homocysteine is to transfer methyl groups, an important intermediate step in the formation of essential amino acids. Vitamins B6, B12 and folic acid are involved in the conversion of dietary protein to methionine, and then to homocysteine and cysteine. A deficiency of these vitamins leads to an accumulation of homocysteine. Homocysteine is regarded as toxic. Even slightly increased homocysteine levels in the blood increase the risk of atherosclerosis, which is caused by increased plaque formation, oxidative damage to endothelial cells, enzymes and proteins through the formation of highly reactive radicals. An increased homocysteine level is therefore an independent risk factor for cardiovascular disease. This means that, even in the absence of other known risk factors such as smoking, hypertension and hypercholesterolaemia, merely the increased concentration of homocysteine in the blood can cause atherosclerotic changes.

Every second to fourth patient with stroke, peripheral arterial disease, heart attack and chronic renal insufficiency has elevated homocysteine levels in the blood.

Reference range
< 15 µmol/l,
Some authors believe that therapy should be given for levels as low as 10 µmol/l and above.

Test materials
In vitro homocysteine passes from the erythrocytes into the plasma. This can lead to increased values in whole blood tubes. For this test, please send us special homocysteine tubes or send us frozen EDTA plasma.
Please request special homocysteine tubes in the laboratory.

Therapy and risk minimisation
As a rule, the following applies: Vitamins are considered to have a protective effect, and thus a balanced diet is the best form of prevention. An additional increased supply of vitamins B6, B12 and folic acid is advisable.

Recommendation
Additionally determining vitamins B6 and B12 and folic acid for ascertaining the initial situation in cases of elevated homocysteine values (> 15 µmol/l).
Therapy monitoring (for compliance!) after 6-8 weeks.

To top

Back