Sustained elevation of blood homocysteine, by damaging endothelial cells, predisposes to premature atherosclerosis of the aorta and its branches, the peripheral arteries, the cerebral arteries, and possibly the coronary arteries. Although homocysteine levels are usually elevated in association with other risk factors, they can be modified by diet and vitamin B supplements. Symptoms, Signs, and Diagnosis Clinical syndromes of arterial occlusion depend on the vessel involved, the extent of obstruction, how rapidly occlusion progresses, and whether collateral flow is adequate. The extremity is cold and pale, and pulses are absent distal to the obstruction. The initial symptom is intermittent claudication.
Similar symptoms related to exertion can occur with involvement of the arm.
Disease progression is indicated by a reduction in the distance that the patient can walk without symptoms. If intermittent claudication is the only symptom, the extremity may appear normal, but the pulses are reduced or absent. In males, impotence is common and depends on the location and extent of occlusion. In femoropopliteal disease, claudication is typically in the calf, and all pulses below the femoral are absent. Pallor of the involved foot after 1 to 2 min of elevation, followed by rubor on dependency, helps confirm arterial insufficiency.