EDN1 and Renal insufficiency: To identify the possible reason for the increase in NGAL and RBP levels in T2DM patients with normoalbuminuric renal insufficiency, we performed single linear regression analysis on the relationships between plasma TNF-α, IL-6, ET-1, and 8-OHdG with urinary NGAL and RBP in T2DM patients with normoalbuminuria.