Comparative Study on the Diagnositc value of Cystatin C and α1-Microglobulin in Diabetic nephropathy

Objective To compare and analyze the diagnostic value of cystatin C(Cys C)and α1-microglobulin(α1-MG) measurements in diabetic nephropathy(DN).and provide reference for clinical diagnosis of DN.Methods Latex enhanced immunoturbidimetric assay was applied to measure levels of Cys C andα1——MG in serum and urine samples from patients with simple diabetic mellitus(DM).DN patients and health controls.Results The levels of Cys C andα1-MG in serum and urine were significantly higher in DN group than those in healthy control group and simple DM group(P0.05 or P0.01),especially in clinical proteinuria subset(all P0.01).The levels of serum Cys C and urineα1-MG were markedly higher in simple DM group than those in health comtrol group(P0.05).The abnormality rate of serum Cys C serum α1-MG urine Cys C and urineα1-MG in DN group was 95.9%,85.0%,25.8% and 43.3% respectively,higher than that in health control group and simple DM group(P0.05 or P0.01),especially in clinical proteinuria subset.The abnormality rates of serum Cys C.serumα1-MG urine Cys C.and urineα1-MG was significantly higher in simple DM group than those in healthcontrol group.The differences were statistically significant.Conclusion As an ideal evaluating marker for glomerular filtration rate(GFR),serum Cys C may provide evidence for early diagnosis of glomerular filtration function impairment in DN.Meanwhile,as a sensitive marker for the tubular injury,urine Cys C contributes to early discovery of tubular impairment complicated with diabetic nephropathy.Combined dctection the serum Cys C and urine Cys C is helpful for carly finding and fully reflection of renal damage in the course of diabetic mellitus,it is suitable to be spreaded and applied in clinic.