Significance of Serum Cystatin C、Urine NAG、Ratio of Urine Microalbumin to Creatinine for Diagnosing Early Renal Impairment in Patients with Diabetes Mellitus

Objective:To evaluate the applicability of serum cystatin C(Cys C) 、urine NAG、ratio of urine microalbumin(mAlb) to creatinine(Cr) for diagnosing early renal impairment in patients with diabetes mellitus. Methods: The concentration of serum Cystatin C was measured by colloidal gold immunoturbidimetric method ,urine mAlb was measured by immune turbidimetry method , urine NAG was measured by 2-point method , the urine micro-malbumin was measured by immunoturbidimetric method, the concentration of serum creatinine and urine creatinine were measured by enzyme method by automatic chemisty analyzer in 68 cases of hypertension patients and 95 cases of health adults.Results:The concentration of Cys C 、urine NAG、ratio of urine mAlb to creatinine in diabetes mellitus group were higher than those in health control group,and there had statistical differences between the two groups( P 0.05) ,but no statistical significance about the concentration of serum Cr(P0.05) .Serum Cys C 、urine NAG、 ratio of urine mAlb to urine urine creatinine joint detect have higher diagnostic value than individual testing .Conclusions:The negative result of qualitative urine protein could not exclude early renal impairment. Through serum Cys C 、urine NAG、urine mAlb / Cr index detection,there should have more important clinical significan for diagnosing early renal damage with diabetes mellitus.