Value of Serum Systatin C Detection in Type 2 Diabetic Nephropathy Diagnosis

Objective: To investigate the changes of serum cystatin C(CysC) in type 2 diabetes mellitus(T2DM) and its significance in the diagnosis of T2DM with renal injury.Methods: According to the levels of urinary albumin excretion rate(UAER),175 T2DM cases were divided into three groups as normal proteinuria(NA) group(UAER30 mg/24 h,n=72);microalbuminuria(MA) group(UAER 30-300 mg/24 h,n=58),and clinical proteinuria(CDN) group(UAER300 mg/24 h,n=45).Serum CysC concentration was determined by immune transmission turbidity method.Serum CysC,creatinine(Scr),blood urea nitrogen(BUN),β2-microglobulin(β2-MG),and UAER were compared among the three groups.Another 60 healthy subjects were included as control group.Results: All the five indices were significantly higher in T2DM patients than in control group(P0.01);CysC,β2-MG,UAER,and Scr levels in MA group were significantly different from that respectively in control group(P0.01 or P0.05,respectively);In CDN group,CysC,Scr,BUN,β2-MG and UAER levels were significantly higher than that respectively in MA group and NA group(all P0.01).In MA group,positively detected rates were not different statistically in CysC,Scr,Bun,and β2-MG(P0.05).But in MA group,the positive rates of CysC and β2-MG were significantly higher than those of Scr and Bun(P0.01).Conclusion: Serum CysC changed early in type 2 diabetic kidney injury,and the level is increasing according to the deteriorating of kidney injury.Serum CysC detection is useful in early diagnosis of type 2 diabetic nephropathy and in evaluating the degrees of renal injury of T2DM.