SOD1 and metabolic syndrome: However, the extent to which dyslipidemia and the activity of antioxidant enzymes may be associated has been barely studied in humans [7,8], and there is more information in this respect from studies on animals [5]; for instance, reduced activity of antioxidant enzymes such as superoxide dismutase-1 (SOD1), catalase, and glutathione reductase has been observed in the liver, heart, and plasma of rats fed on a high-fat diet [5,6,9,10].