REDUCED OXIDATIVE SUSCEPTIBILITY OF LDL FROM PATIENTS PARTICIPATING IN AN INTENSIVE ATHEROSCLEROSIS TREATMENT PROGRAM

The goal of this investigation was to determine whether participation in an atherosclerosis treatment program would reduce the oxidative sus ceptibility of LDL from patients with coronary artery disease. The tre atment program included intensive exercise therapy, stress management, and consumption of a diet containing 10% fat. The size and antioxidan t and lipid contents of LDL particles from 25 patients were analyzed a t baseline and after 3 mo of therapy. The susceptibility of LDL to cop per-mediated oxidation was measured by a conjugated diene assay and he adspace gas chromatography (HSGC). Atherosclerosis treatment significa ntly reduced plasma total cholesterol and apolipoprotein B concentrati ons and the molar ratio of LDL cholesterol eater to apolipoprotein B ( P < 0.01). The LDL content of alpha-tocopherol and beta-carotene was i ncreased (27% and 17%, respectively, P < 0.04) and the molar ratio of LDL cholesterol eater the sum of LDL alpha-tocopherol and LDL beta-car otene decreased from 159 at baseline to 122 at 3 mo (P < 0.01). The la g phase of LDL conjugated diene formation increased 24%, whereas the m aximum rate of oxidation slowed 29% (P < 0.01). As assessed by HSGC, c opper-catalyzed formation of volatile lipid oxidation products was red uced 15% (P < 0.007); the reduction in volatiles was correlated with a n increase in the alpha-tocopherol content of LDL (r = -0.48, P < 0.01 ). The principal determinants of reduced LDL oxidative susceptibility were the particle contents of alpha-tocopherol and beta-carotene. To o ur knowledge, this is the first report to document a reduction in LDL oxidation in coronary artery disease patients undergoing atheroscleros is-reversal therapy.