TFRC and type 2 diabetes mellitus: The balance between O2•- and •OH in T2DM is modulated by three critical factors: First, T2DM disease duration: Long-term hyperglycemia (≥10 years) promotes iron accumulation in skeletal muscle via upregulating transferrin receptor 1 (Van Huynh et al., 2023), increasing •OH production by enhancing Fenton reactions.