SIRT2 and diabetic kidney disease: This study was designed to investigate serum SIRT2 concentrations in the context of diabetic nephropathy by comparing patients with T2DM with and without nephropathy to healthy controls, and by assessing their relationships with established renal markers such as eGFR and UACR in order to determine whether SIRT2 may serve as a clinically meaningful biomarker that reflects renal injury beyond conventional indices and supports early detection and risk stratification.