Effect of 12-month statin therapy on antioxidant potential of LDL and serum antioxidant vitamin concentrations

Abstract

BACKGROUND. Statins are known to cause short-term reduction in serum lipid-soluble antioxidant concentrations, but their long-term effects are not known. AIM: We randomised 104 subjects with CHD and hypercholesterolaemia to receive either atorvastatin or simvastatin treatment for 52 weeks and measured the antioxidant potential of LDL and serum antioxidant vitamin concentrations. METHOD: Initial daily dose for both statins was 20 mg. RESULTS: LDL antioxidant capacity and serum α-tocopherol, γ-tocopherol and β-carotene concentrations decreased by 22%-35% with both statins during the first 12 weeks' therapy (P < 0.01 for all). After 52 weeks' therapy, the concentrations of serum γ-tocopherol in the simvastatin group and serum β-carotene in both treatment groups returned to baseline levels, while the concentrations of serum γ-tocopherol in the atorvastatin group and LDL antioxidant capacity and serum α-tocopherol in both treatment groups remained reduced (P < 0.001 for all). The LDL antioxidant capacity:LDL-cholesterol and the serum α-tocopherol:LDL-cholesterol ratios were significantly elevated with both statins after 12 and 52 weeks (P < 0.001 for all). Statistically significant increases were also observed for corresponding ratios of the less abundant vitamins γ-tocopherol and β-carotene. CONLUSIONS: Some of the decreases in serum lipid soluble antioxidant vitamins reported in short-term statin interventions may become attenuated when therapy continues longer. The relative antioxidant capacity of LDL particles increased during the 52-week treatment, suggesting that the oxidation resistance of LDL particles did not become impaired and that their atherogenicity did not increase.