摘要目的 观察糖尿病患者血清和尿半胱氨酸蛋白酶抑制剂C(cystatin C)的浓度变化并与临床常用反映肾功能改变的指标进行比较,探讨其对糖尿病早期肾损伤的临床评估价值.方法 选择本院首次确诊为糖尿病患者82例,按24 h尿白蛋白定量程度分成3组,以健康志愿者为对照,分别观察血清cystatin C、血清肌酐(Scr)、尿cystatin C、N-乙酰-β-葡萄糖苷酶(NAG)、α1微球蛋白(MG),99mTc肾小球滤过率(GFR),内生肌酐清除率(Ccr)-GFR等临床指标并行统计分析.结果 尿cystatin C浓度及其异常率的升高早于血清cystatin C.血清cystatin C与99mTc-GFR的相关性较Ccr-GFR与99mTc-GFR的相关性好(r=-0.88和r=0.84,P<0.01).尿cystatin C与NAG的相关性和尿cystatin C与α1-MG的相关性之间差异无统计学意义(r=0.89和r=0.90,P>0.05).血清cystatin C的工作特征曲线下面积(AUCROC)大于Ccr-GFR的AUCROC(0.897±0.094和0.757±0.228,P<0.01);尿cystatin C的AUCROC大于NAG的AUCROC(P<0.05),与α1-MG的AUCROC差异无统计学意义(P>0.05).尿cystatin C的似然比(LR)大于血清cystatin C的LR.结论 血清和尿cystatin C水平可较早期地反映糖尿病患者肾功能的损伤,其反映肾小管功能的损伤早于肾小球功能的损伤.

abstractsObjective To detect the changes of serous and urinary cystatin C concentration compared with clinic general renal function indexs, and to evaluate the value of cystatin C for the diagnosis of early kidney injuryin diabetic patients. Methods Eighty-two patients preliminayily diagnosed as diabetes were divided into three groups according to the degree of 24 hours urinary microalbumin quantitation. Twenty-eight healthy volunteers were selected as control. Serous cystatin C, serous creatinine, urinary cystatin C, urinary N-acetyl-β-d-glucosaminidase (NAG), urinary α1-microglobulin(α1-MG), 99mTc-DTPA glomerular filtration rate (99mTc-GFR) and creatinine clearance rate resulted from Cockcroft-Gault equation (Ccr-GFR) were measured and statistical analysis was performed. Results The concentration and abnormal rate of urinary cystatin C increased before those of serous cystatin C were higher. Correlation between serous cystatin C and 99mTc-GFB was superior to that between Ccr-GFR and 99mTc-GFR (r=-0.88 vs r=0.84, P< 0.01). Correlation between urinary cystatin C and NAG was similar to that between urinary cystatin C and α1-MG (r=0.89 vs r=0.90, P<0.01). Area under curve of receiver operating characteristic (AUCROC) of serous cystatin C and Ccr-GFR was significantly different (0.897±0.094 vs 0.757±0.228, P<0.01). AUCROC of urinary cystatin C was superior to that of NAG (P<0.05), and no difference to that of α1-MG was found(P> 0.05). Likelihood ratio (LR) of urinary cystatin C was superior to that of serous cystatin C. Conclusion Serous and urinary cystatin C concentration can diagnose early diabetic kidney injury, which can earlier reflect impairment of kidney tubule than that of glomerulum.