SIRT1 and Hyperglycemia: Conversely, normalization of SIRT1 exhibited a protective effect against oxidative stress and hyperglycemia-induced cardiac injury by activating the Nrf2 pathway and Nrf2-dependent antioxidant genes (30, 31), or by promoting mitochondrial fusion/inhibiting mitochondrial fission and subsequent suppression of mitochondria-derived ROS production (32, 33).