In our study, HbA1c in the G5 group of DKD was significantly better than that in the G3 and G4 groups, and the main reason may be that the low GFR of DKD patients in the G5 group led to the decreased ability of the kidneys to expel insulin and hypoglycemic drugs, and the decrease of renal gluconogenesis (30, 31). Here, INS is linked to diabetic kidney disease.