血清半胱氨酸蛋白酶抑制剂C与肌酐在评价糖尿病患者肾小球滤过功能中的比较研究

Comparison of serum Cystatin C and creatinine in the detection of glomeruli filtration function in diabetic patients

目的与血清肌酐(SCr)、肌酐清除率(Ccr)比较,评价血清半胱氨酸蛋白酶抑制剂C(CystatinC)在2型糖尿病患者肾小球滤过功能改变中的临床应用价值。方法以99mTcDTPA清除率测得的肾小球滤过率(GFR)作为诊断评价的金指标,比较CystatinC、Scr、Ccr与GFR的相关性,用受试者工作特征曲线(ROC)评价上述指标检测肾小球滤过功能的准确性。结果51例患者血CystatinC、Scr及Ccr与99mTcDTPA清除率相关系数分别为-0.744、-0.658、0.625(P值均<0.001)。3项指标ROC曲线下的面积(AUC)分别为0.891、0.77、0.753,且CystatinC与Ccr两者间的AUC差异有统计学意义(P<0.05)。ROC曲线阈值移动发现血清CystatinC判定肾小球滤过功能减退的最佳诊断界值(cutoff值)为1.02mg/L,此时诊断的灵敏度和特异性分别为92.3%、68.4%,而以SCr参考值上限(133μmol/L)和Ccr的参考值下限(80ml/min)为cutoff值,则不能同时得到理想的诊断灵敏度和特异性。结论CystatinC是一较理想的反映GFR血清标志物,建议在常规检测SCr、Ccr的基础上,联合应用CystatinC可更早地发现2型糖尿患者GFR的改变。

Objective This study was designed to estimate the value of Cystatin C, compared to routine marker (Scr、Ccr), as the screening marker for reduced GFR in type 2 diabetes patient. Methods The study was performed on 51 type 2 diabetic patients, and GFR was estimated by the plasma clearance of ~ 99m Tc-DTPA. Sensitivity and specificity for the diagnosis of renal impairment were calculated by receiver operating characteristic (ROC) curves for above three parameters.Results Correlation coefficients with ~ 99m Tc-DTPA were-0.744 for serum Cystatin C,-0.658 for serum creatinine, 0.625 for creatinine clearance (all P<0.001). Areas under the ROC curve (AUC) were 0.891 for Cystatin C, 0.77 for creatinine and 0.753 for creatinine clearance. The area under the receiver operating characteristics curve (AUC) was statistically different between serum Cystatin C and creatinine clearance (P<0.05). ROC plot suggests the optimum cut off for Cystatin C was 1.02mg/L, the value of sensitivity was 92.3 %, the specificity was 68.4 %. Conclusion Serum Cystatin C is a more sensitive and specific maker for GFR, and if combine with serum creatinine and creatinine clearance, it can early reflect the changes of the GFR in type 2 diabetes.