Combination of low-dose folic acid and pyridoxine for treatment of hyperhomocysteinaemia in patients with premature arterial disease and their relatives.

Hyperhomocysteinaemia is an independent risk factor for atherosclerotic disease and venous thrombosis. The optimal homocysteine-lowering vitamin dose and target total homocysteine (tHcy) concentration are currently unknown. We prospectively studied the homocysteine-lowering effect after 8 weeks low-dose combination of folic acid (0.5 mg) and pyridoxine (100 mg) in 49 hyperhomocysteinaemic persons (33 patients with documented premature arterial disease and 16 of their first-degree relatives). Hyperhomocysteinaemia was in both sexes defined as fasting tHcy concentration > 12 micromol/l and/or post-methionine load tHcy concentration > 38 micromol/l. Low-dose vitamin therapy significantly reduced fasting tHcy concentration (median 13.9 to 9.3 micromol/l, reduction 32% (95% CI: 27-37%)) and post-load tHcy concentration (median 55.2 to 36.5 micromol/l, reduction 30% (95% CI: 25-35%)). Fasting tHcy reduction was similar in women and men, as well as in patients and relatives. Post-load tHcy reduction was significantly less in men compared to women (P = 0.04) and in relatives compared to patients (P = 0.03). Although low-dose combination of folic acid and pyridoxine results in a substantial reduction of tHcy concentrations (30-32%) in subjects with hyperhomocysteinaemia, the normalisation percentage to predefined criteria was less impressive (49%).