PIMREG and type 2 diabetes mellitus: Therefore, detecting the expression of Cat-S which is a vascular injury marker and determining whether serum Cat-S in T2DM patients is a risk factor for the incidence of DKD are of great significance for preventing the incidence of DKD, strengthening early screening for DKD, and searching for new therapeutic targets for the treatment of DKD in T2DM patients.