Enhanced Susceptibility to Oxidation and Diminished Vitamin E Content of LDL from Patients with Stable Coronary Artery Disease

modification of LDL as an important trigger in a com-plex chain of events leading to atherosclerosis. We investigated the occurrence of enhanced susceptibility of LDL to oxidation and decreased vitamin E concentra-tion in LDL as additional risk factors promoting athero-sclerosis among patients with established coronary ar-tery disease (CAD). Methods: We examined 132 patients with angiographi-cally confirmed CAD and compared them with 111 healthy control individuals. We measured conjugated diene production to assess susceptibility of LDL to copper-mediated oxidation. Vitamin E content of LDL was measured by HPLC. Results: The mean lag time of LDL oxidation and LDL a-tocopherol/LDL-cholesterol ratio were lower in the patients with CAD (55 6 14 min and 2.4 6 1.0 mmol/ mmol) than in the controls (63 6 13 min and 2.9 6 1.