Antioxidant status of hypercholesterolemic patients treated with LDL apheresis

Abstract

Oxidation of low density lipoprotein is involved in the pathogenesis of atherosclerosis. Epidemiological studies suggest a negative correlation between the occurrence of cardiovascular diseases and blood concentrations of lipophilic antioxidants such as vitamins A and E and beta-carotene. Trace elements, such as selenium, zinc, and copper, are involved in the activity of the antioxidant enzymes glutathione peroxidase and superoxide dismutase. The aim of this study was to determine the antioxidant and trace element status of patients with severe hypercholesterolemia who had been treated with dextran-sulphate low-density lipoprotein apheresis in comparison with two control populations, normocholesterolemic subjects and untreated hypercholesterolemic patients. Our results showed that, patients treated with LDL apheresis, compared with normocholesteromic subjects, were not deficient in vitamin E, beta-carotene, and copper, but had lower plasma levels of selenium, zinc, and vitamin A. The low selenium and vitamin A levels were due to the LDL-apheresis treatment, and the hypercholesterolemia might have provoked the low plasma levels of zinc. The study pointed out the potential benefits of supplemental selenium, zinc, and vitamin A in patients being treated with LDL apheresis.

Erythrocyte Antioxidant Enzyme Activities and Lipid Peroxidation in Patients with Types IIb and IV Hyperlipoproteinemias

“…However, in the literature some conflicting results such as decreased plasma SOD in combined hyperlipoproteinemic human subjects (Araujo et al 1995), and increased plasma SOD activity in cholesterol-fed rabbits were reported (Silva et al 1995). In another study, low plasma zinc and selenium levels were reported in hypercholesterolemic subjects (Lepage et al 1996). Since selenium is the cofactor of GSH-Px and zinc is a constituent of SOD, the observed reduction of GSH-Px and SOD activities in this study might be attributable to low selenium and zinc levels.…”

Acute and long-term effects of low-density lipoprotein (LDL)-apheresis on oxidative damage to LDL and reducing capacity of erythrocytes in patients with severe familial hypercholesterolaemia

“…Moreover, an increased level of GSH was reported recently in granulocytes as an acute effect of HELP [39]. On the other hand, other antioxidant factors, such as the lipophilic vitamins α-tocopherol and β-carotene, and the plasmalogen content of plasma phospholipids, have been reported previously to increase the resistance of LDL to oxidation [35,38,40,41].…”

Acute and long-term effects of low-density lipoprotein (LDL)-apheresis on oxidative damage to LDL and reducing capacity of erythrocytes in patients with severe familial hypercholesterolaemia

“…Such a finding could be the effect of an increase in the activities of free radical scavenging enzymes in erythrocytes, as observed by Schettler et al [10,37] during regular LDL-apheresis by the HELP technique. On the other hand, other antioxidant factors, such as the lipophilic vitamins α-tocopherol and β-carotene, and the plasmalogen content of plasma phospholipids, have been reported previously to increase the resistance of LDL to oxidation [35,38,40,41]. On the other hand, other antioxidant factors, such as the lipophilic vitamins α-tocopherol and β-carotene, and the plasmalogen content of plasma phospholipids, have been reported previously to increase the resistance of LDL to oxidation [35,38,40,41].…”