SOD2 and hypothyroidism: Our findings are consistent with previous studies that reported increased lipid peroxidation in the liver and increased serum 8-OHdG levels, both indicative of increased oxidative damage to the liver in hypothyroidism (52, 54–58). This is associated with a reduced expression of the mitochondrial antioxidant enzymes SOD2, GPX4 and PRDX3, suggesting of impaired liver antioxidant defences.