Mild hyperhomocysteinemia is an independent risk factor of arterial vascular disease

Evidence of a positive association between mild hyperhomocysteinemia and ar terial vascular disease has been accumulating in the last decade. Mild hype rhomocysteinemia acts as an independent vascular risk factor with equal str ength as hypercholesterolemia and smoking. If jointly present with hyperten sion and smoking, its effect seems synergistic. This could make the outcome of homocysteine-lowering intervention beneficial, particularly in cases wi th concomitance of conventional vascular risk factors. So far, however, dat a on the clinical outcome of homocysteine-lowering treatment with a simple, safe, and cheap vitamin regimen are lacking. Trials investigating a benefi cial clinical effect of homocysteine-lowering treatment using folic acid in a dose ranging from 0.2 to 5 mg daily, alone or in combination with vitami n B-12 with or without vitamin B-6 versus placebo, are ongoing. Furthermore , exploration of the unifying mechanism by which increased homocysteine lev els may lead to both arterial and venous occlusions is warranted. These lin es of investigations have to provide the ultimate proof of causality of hyp erhomocysteinemia in vascular disease in the near future.