Therefore, in this study, we detected the expression of serum Cat-S in DKD patients, analyzed the correlation between serum Cat-S and the severity of DKD and analyzed whether serum Cat-S was a risk factor for DKD in T2DM patients, and investigated the diagnostic value for DKD, to provide a theoretical basis for early screening of DKD. Here, PIMREG is linked to type 2 diabetes mellitus.