Abstract:
In recent years hyperhomocysteinemia has been established as a new risk factor for
neural tube defects, arterial cardiovascular disease, and venous thrombosis. Concerning
vascular problems, it first became clear that hyperhomocysteinemia might be (though
not proven) a risk factor for arterial disease as observed in case-control studies,
as well as in prospective analysis. More recently, the subject of hyperhomocysteinemia
and venous thrombosis has received much attention. In this article, we discuss the
issue of hyperhomocysteinemia, in general, the known causes of hyperhomocysteinemia
and the association with venous thrombosis. Special attention is given to the value
of the methionine loading test to diagnose hyperhomocysteinemia. An association of
venous thrombosis and hyperhomocysteinemia has now been documented in several case
control studies, but only in one prospective analysis. Thus far, there is limited
evidence for a causual relationship for mild hyperhomocysteinemia in venous thrombosis.
Briefly, the possible mechanisms of how hyperhomocysteinemia can lead to venous thrombosis
are discussed. The article ends with therapeutic options to treat hyperhomocysteinemia
(hyperhomocysteinemia can easily be treated with vitamins) and the description of
a study that is presently being undertaken in an international multicenter design.
This placebo-controlled study might resolve the question of whether lowering of homocysteine
levels is of any clinical relevance in preventing recurrent venous thrombosis.
Keywords:
homocysteine - hyperhomocysteinemia - venous thrombosis - vitamins - placebo-controlled
trial
