[The prevalence of hyperhomocysteinemia in thromboangiitis obliterans. Does homocysteine play a role pathogenetically?].

OBJECTIVE: As hyperhomocysteinaemia is known to be an important risk factor in the early onset of arteriosclerotic occlusive disease and leg-vein thrombosis, we investigated the prevalence of hyperhomocysteinaemia in patients with thromboangiitis obliterans (TAO), a condition predominantly affecting peripheral arteries and veins.

PATIENTS AND METHODS: Plasma homocysteine (HC), before and after administration of methionine (0.1 g/kg) as well as serum folic acid, vitamins B6 and B12 were measured in 15 patients with TAO (12 men, 3 women; mean age 33.3 years: group 1), in 15 non-smokers without peripheral vascular disease (group 2) and 15 smokers without peripheral vascular disease (group 3). At the time of the study, of those in group 1 seven were active smokers, seven were ex-smokers and one was a non-smoker.

RESULTS: Before methionine administration four patients (27%), none of the healthy non-smokers and one smoker without vascular disease (7%) had increased HC levels (> 13.9 nmol/ml). The difference between groups 1 and 2 was statistically significant (P < 0.05), but not that between groups 1 and 3 and between 2 and 3. 4 hours after methionine increased HC levels (> or = 31 nmol/ml) were measured in nine patients but in none of the healthy controls. The difference between patients and the two control groups without vascular disease was clearly significant (P = 0.0107). There was a difference in folic acid levels between the patients and the smokers without vascular disease: in eight patients (53%) the levels were in the lower third of normal, in six (40%) they were in the middle and in one (7%) in the upper third. Corresponding levels in group 3 were: four (27%), three (20%) and eight (53%).

CONCLUSION: Hyperhomocysteinaemia occurs frequently in patients with TAO. It may play an important and nicotine-independent role in its pathogenesis.