尿胱抑素C在2型糖尿病肾病肾小管损伤早期诊断中的价值

Diagnosis Value of Urinary Cystatin C in Type 2 Diabetic Nephropathy Renal Tubular Injury

目的：探讨尿胱抑素 C（Cys C）在2型糖尿病肾病（DN）肾小管损伤早期诊断中的价值。方法2型糖尿病（T2DM）确诊病例72例，并按1989年 Mogensen提出的方法，根据尿清蛋白排泄率（UAER）分为三组：T2DM正常清蛋白尿组（UAER＜30 mg／24h）26例，T2DM微量清蛋白尿组（UAER 30～300 mg／24h）28例，T2DM大量清蛋白尿组（UAER＞300 mg／24h）18例，同时测定尿Cys C，α1微球蛋白（α1MU）和β2微球蛋白（β2MU）进行比较。结果 T2DM组尿Cys C为0.106±0.076 mg／L，明显高于对照组0.032±0.013 mg／L（t值为27.8，P＝0.000）；T2DM正常清蛋白尿组与对照组比较，尿Cys C与β2MU，差异均有统计学意义（P＜0.05），而α1MU，差异无统计学意义（P＞0.05）；T2DM患者尿 Cys C与α1MU，β2MU的相关性分析，尿Cys C与α1MU呈现明显的正相关（r＝0.88，P＝0.000），与β2MU也呈明显正相关（r＝0.92，P＝0.000）；以 UAER＞30 mg／24h为截点作T2DM患者尿Cys C与α1MU，β2MU的ROC曲线，其曲线下分布面积（AUC）分别为0.911，0.806，0.899，经比较尿Cys C与α1MU的AUCROC的差异具有统计学意义（P＜0.05），尿Cys C与β2MU的AUCROC差异无统计学意义（P＞0.05）。结论尿Cys C的灵敏度和特异度与β2MU相当，要优于α1MU，且干扰因素少，是一种诊断DN早期肾小管损伤的敏感指标。

Objective To study the diagnosis value of urinary cystatin C （Cys C）in type 2 diabetic nephropathy （DN）renal tubular injury.Methods 72 cases of type 2 diabetes mellitus （T2DM）were divided into three groups using urinary albumin excretion rate （UAER）according to the method proposed by Mogensen in 1989,T2DM normal albumin urine group （UAER〈30 mg/24h）26 cases,T2DM Microalbuminuria urine group （UAER30~300 mg/24h）28 cases,T2DM Macroalbuminuria urine group （UAER〉300 mg/24h）18 cases,urinary Cys C,α1MU andβ2MU were compared.Results T2DM urinary Cys C was 0.106±0.076 mg/L,significantly higher than the control group of 0.032±0.013 mg/L （t=27.8,P=0.000）.Urina-ry Cys C andβ2MU （P〈0.05）both,while theα1MU P〉0.05 in T2DM group compared with the control group.Urinary Cys C andα1MU showed a significant positive correlation （r=0.88,P=0.000）,andβ2MU also showed a significant posi-tive correlation with Urinary Cys C in T2DM patients correlation analysis （r=0.92,P=0.000）.Using UAER〉30 mg/24h as cut-off points made urinary Cys C,α1MU,β2MU ROC curve in T2DM patients,the area under the curve （AUC）were 0.911,0.806,0.899 respectively,urinary Cys C andα1MU has the statistically significant （P〈0.05）and no difference be-tween urinary Cys C withβ2MU （P〉0.05）in AUCROC.Conclusion The sensitivity and specificity of urinary Cys C was comparable toβ2MU,which was better thanα1MU.It is a sensitive indicator of early renal tubular injury in DN.