SOD2 and hyperlipidemia: In addition to increasing ROS production, hyperglycemia and hyperlipidemia aggravate oxidative stress through reducing antioxidant capability, evidenced by the reduction in reduced to oxidized glutathione (GSH/GSSG ratio) in hyperglycemia, and reduced superoxide dismutase 1(SOD1) and SOD2 expression in hyperlipidemia in human and rat β cells [14,54,55].