After adjusting for all possible confounders using multivariable logistic regression analysis serum cystatin C (P <0.001), SBP (P = 0.02), FBG (P =0.001), TC (P <0.01), TG (P <0.001), LDL (P <0.001), VLDL (P <0.001), HDL (P<0.061) and duration of T2DM (P =0.04) were identified to be significantly associated with diabetic nephropathy. Here, CST3 is linked to diabetic kidney disease.