血清胱抑素C检测在评价2型糖尿病早期肾功能损害中的应用

目的探讨血清胱抑素C（CysC）水平测定在2型糖尿病患者不同肾损害期中的临床诊断价值。方法采用乳胶颗粒增强免疫透射比浊法（PETIA）测定2型糖尿病患者150例血清CysC水平，同时测定血清肌酐（SCr）、尿素氮（Bun）、β2-微球蛋白（β2-MG）及晨尿微量清蛋白，采用受试者工作特征曲线（ROC）评价CysC的诊断效能。结果2型糖尿病组血清CysC水平明显高于健康对照组（P〈0．01），其中无糖尿病肾病（无DN）组、Ⅲ期DN组以及Ⅳ、Ⅴ期DN组间血清CysC水平比较差异有统计学意义（P〈0．01）。在无DN组中，血清CysC、β2-MG、SCr、Bun四项指标的异常检出率无显著差异（P〉0．05），但在Ⅲ期DN组中，CysC、β2-MG的异常检出率明显高于SCr和Bun（P〈0．01）。以尿微量清蛋白为标准，2型糖尿病患者中DN的诊断敏感性和特异性，血CysC（以1．22mg／L为界值）分别为72．1％、88．6％，β2-MG（以2．82mg／L为界值）分别为79．0％、92．3％，SCr（以101μmol／L为界值）分别为46．2％、93．5％，Bun（以6．19mmol／L为界值）分别为41．7％、84．3％。CysC、β2-MG诊断DN的敏感性显著高于SCr和Bun（P〈0．01），4项指标诊断DN的特异性差异无统计学意义（P〉0．05）。CysC、β2-MG、SCr、Bun的ROC分别为0．781、0．812、0．645、0．619。结论血清Cys C是一个灵敏、准确、可靠的反映肾小球滤过功能的指标，有助于2型糖尿病肾病的早期诊断。

Applicaton of serum cystatin C detection in assessment of early renal function injury in patients with type 2 diabetes mellitus

Objective To explore the clinical diagnostic value of serum cystatin C detection indifferent stages of renal impairment in patients with type 2 diabetes mellitus. Methods The serum lev-el of cystatin C was detected by particle-enhanced turbidimetric immunoassay (PETIA);while serum creatinine (SCr), blood urea nitrogen (Bun), β2-microglobulin (β2-MG), morning urine microalbumin were measured in 150 patients with type 2 diabetes mellitus. The area under receiver operating charac-teristic curve (ROC) was applied to evaluating the diagnostic efficiency of cystatin C. Results The se-rum cystatin C level was much higher in diabetes group than that of healthy control group (P<0.01).The differences among non-diabetic nephropathy (non-DN) group, DN group (including DN stage Ⅲ group, stage Ⅳ group and stage Ⅴ group) were statistically significant in serum cystatin C level (P<0. 01). The abnormal detection rates for serum cystatin C,β2-MG, SCr and Bun were not statistically different in non-DN group (P>0. 05), but the abnormal rates for serum cystatin C and β2-MG were significantly higher than those of SCr and Bun in stage Ⅲ group (P<0. 01). With a cutoff value of 1.22 mg/L, sensitivity and specificity were 72. 1% and 88. 6% for serum cystatin C;with a cutoffvalue of 2.82mg/L, sensitivity and specificity were 79.0% and 92.3% for β2-MG;with a cutoff valueof 101 μmol/L, sensitivity and specificity were 46.2% and 93.5% for SCr;and with a cutoff value of6.19 mmol/L, sensitivity and specificity were 41.7% and 84.3% for Bun, respectively. The sensitivi-ty of serum cystatin C and β2-MG was significantly higher than that of SCr and Bun(P<0.01). The specificity for above four markers was not statistically different (P>0.05). The area under ROC for cystatin C, β2-MG, SCr and Bun was 0. 781, 0. 812, 0. 645 and 0. 619 respectively. Conclusion Serum cystatin C is a sensitive, accurate and reliable marker for glomerular filtration rate, Which is helpful for early diagnosis of type 2 diabetic nephropathy.