Levels of serum ferritin (A) and LDH (B) in DN patients and healthy controls. Levels of serum HMGB1 (C) and mRNA expression of HMGB1 (D) in DN patients and healthy controls. Real-time PCR was used to detect the expression of ferroptosis-related proteins, including ACSL4, PTGS2, NOX1, and GPX4 (E). **P<0.01, ***P<0.001, compared with control.