Clinical Significance Of Detection Cystatin C In Early Diabetic Nephropathy

Purpose:We Take 115 cases of type 2 diabetic patients who live in our hospital as research subjects, to explore the Clinical significance of detection of serum cystatin C in the early diagnosis of type 2 diabetic nephropathy and the relationship between glomerular filtration rate and serum cystatin C.Method:In accordance with WHO 1999 diagnosis and classification of diabetes mellitus ,we selected 115 patients with type 2 diabetes who has been confirmed, 74 patients were male, 41 patients were female, 30-80 years old. while patients in the diet patterns of life, count the amount of urine specimens of 24 hours, take l0ml of them to detect the albumin excretion (UAE). The next morning after 10 hours'fasting ,draw venous blood and immediately inspected, measured cystatin C (CysC), total cholesterol, triglycerides, low density lipoprotein cholesterol, high density lipoprotein cholesterol, fasting plasma glucose (FPG ), blood urea nitrogen (BUN), serum creatinine (SCr), glycated hemoglobin and retinol-binding protein. Calculated glomerular filtration rate by a simplified MDRD equation, calculated creatinine clearance (CCr) by CG equation. According to the measured results of urinary albumin excretion, patients were divided into three groups:①simple diabetic group (24-hour urinary albumin excretion <30 mg);②early DN group (24-hour urinary albumin excretion = 30 ~ 300 mg);③clinical DN group ((24-hour urinary albumin excretion≥300 mg). Compare the different indicators'detection rate of renal dysfunction at different levels of proteinuria. Analyze the correlation between CysC, SCr , CCr and eGFR. The patients who with normal albuminuria are divided into two groups by eGFR :eGFR <60ml/min/l.73m2 group and eGFR≥60ml/min/l.73m2 group. Between the two groups , serum cystatin C and other indicators are compared and analyzed statistically.Result:⒈eGFR using in detection of renal dysfunction was significantly better than that of Cys-c, SCr and CCr, the difference was statistically significant (p <0.01), the detection rate of serum cystatin C and CCr is equal, no statistical difference ( p> 0.05), was higher than that of both SCr and BUN, the difference was statistically significant (p <0.01). Especially in the normal albuminuria group, the detection rate of CCr,and BUN is very low.⒉With the increase of the amount of urinary albumin, eGRF and CCr decreased ,serum cystatin C ang serum creatinine increased.⒊CysC and eGFR had a good correlation, r =- 0.625, but its relevance is less than CCr and SCr.⒋In the normal albuminuria group,the patients'level of cystatin C whose eGFR less than 60ml/min/l.73m2 was significantly higher than the patient whose eGFR more than 60ml/min/l.73m2 .Conclusion:The serum cystatin C and glomerular filtration rate have good correlation, and serum cystatin C can prompt an early decline in glomerular filtration rate in diabetic patients with normal proteinuria .