Raised plasma homocysteine as a risk factor for idiopathic and recurrent deep-vein thrombosis

ABSTRACT

Previous studies have suggested that hyperhomocysteinemia [Hyper-Hcy] may be a risk factor for venous thrombosis. To assess the risk of venous thrombosis-associated with Hyper-Hcy, we studied plasma total homocysteine [tHcy] levels in patients with deep venous thrombosis and in normal control subjects. Fasting tHcy levels were measured in 40 consecutive patients with objectively diagnosed deep venous thrombosis and in 20 healthy controls matched to the patients according to age and sex. Hyper-Hcy was defined as plasma total homocysteine level > 15 micro mol/l. Plasma homocysteine level was significantly higher in patients than in controls. It was significantly higher in patients with idiopathic [unprovoked] vein thrombosis than in patients with secondary disease [associated with at least one predisposing factor]. Mean homocysteing was higher in male than in female patients and increased with age. Hyperhomocysteinemia was more frequent in patients with relapsing disease than in those presenting with a single episode. Mean homoqsteine level was similar in patients presenting with either proximal or calf vein thrombosis. Mild Hyper-Hcy is an independent risk factor for deep- vein thrombosis, more prevalent in patients with idiopathic or recurrent disease. The next question to be answered is whether homocysteine-lowering therapy - folic acid, vitamin 36 or vitamin B12 contributes to the prevention of recurrent venous thrombosis