Hyperhomocysteinaemia as a risk factor for deep-vein thrombosis.

OBJECTIVE: Several studies have shown a relation between hyperhomocysteinaemia and vascular disease. To assess the risk of deep-vein thrombosis (DVT) associated with hyperhomocysteinaemia, we studied plasma homocysteine levels in patients with deep-vein thrombosis and in normal control subjects. MATERIALS AND METHODS: We measured plasma homocysteine levels in 48 patients with deep-vein thrombosis and in 33 healthy controls matched to the patients according to age and sex. Plasma homocysteine levels were measured with high performance liquid chromatography and fluorescence detection. Hyperhomocysteinaemia was defined as a plasma homocysteine level about 15 micromol/L in both groups. The diagnosis of all patients with deep-vein thrombosis (n=48) was verified by Doppler ultrasonography. RESULTS: Plasma homocysteine levels were found to be increased in the deep-vein thrombosis group compared the control group (p<0.001, t-test). The mean plasma homocysteine level in the patients was 17.1 SD 5.13 micromol/L (range 6.4-31.3), and that in the controls was 9.0 SD 1.27 micromol/L (range 6.0-11.5). The association between elevated homocysteine levels and venous thrombosis was stronger among men than among women. CONCLUSIONS: The increased plasma homocysteine levels we have observed may have a causative role in the development of deep-vein thrombosis.