Genetically Reduced Antioxidative Protection and Increased Ischemic Heart Disease Risk

Abstract
Background— Extracellular superoxide dismutase (EC-SOD) is an antioxidative enzyme found in high concentrations in the arterial wall. Two to three percent of all people in Denmark carry an R213G substitution, which increases plasma concentration 10-fold. This may reduce arterial wall EC-SOD concentrations, increase intimal LDL oxidation, and therefore may accelerate atherogenesis. Our primary hypothesis was that EC-SOD-R213G predisposes to ischemic heart disease (IHD). The secondary hypothesis was that EC-SOD-R213G offers predictive ability with respect to IHD beyond that offered by measurements of plasma EC-SOD and autoantibodies against oxidized LDL (oxLDL). Methods and Results— The primary hypothesis was tested in a prospective, population-based study of 9188 participants from The Copenhagen City Heart Study with 956 incident IHD events during 23 years of follow-up and retested cross-sectionally with independent case populations of patients with IHD (n=943) or ischemic cerebrovascular disease (ICVD) (n...