eGFR-MDRD和Cys C糖尿病肾病患者早期诊断的 价值分析

摘要:目的　探讨血清胱抑素C（Cystatin C，Cys C）与利用Cys C估算的eGFR-cys对于早期诊断糖尿病肾病的临床应用价值。方法　根据尿白蛋白排泄率将126例2型糖尿病患者分为单纯糖尿病组和糖尿病肾病组，对其空腹血糖（FBG）、餐后2 h血糖（2hPBG）、糖化血红蛋白（HbA1c）、24 h尿蛋白定量（24 h UPQ）、血肌酐（Scr）、尿素氮（BUN）、血清胱抑素C（Cys C）进行检测，根据简化的MDRD方程估算肾小球滤过率（eGFR），使用CHINAcys方程估算eGFR（eGFR-cys）。使用受试者工作特征曲线（Receiver Operator Characteristic curve，ROC）分析各项指标的诊断价值。结果　与单纯糖尿病组相比，糖尿病肾病组的24 h UPQ、BUN、Scr、Cys C显著升高，eGFR-MDRD、eGFR-cys显著降低，差异有统计学意义（P＜0.01）。Cys C及eGFR-cys与24 h UPQ、Bun、Scr及eGFR-MDRD均有一定的相关性，Cys C与eGFR-MDRD相关性最大，相关系数为-0.681；4 h UPQ、Cys C与eGFR-cys的AUC＞0.75，这3项指标诊断DN的效能优于BUN、Scr与eGFR-MDRD。当以eGFR-cys＜60［ml·min-1（173m2）-1］，Cys C＞0.98 mg/L为截点时，eGFR-MDRD+Cys C联合诊断DN的敏感度和约登指数分别为87.35%与0.710，均高于BUN、Cys C、Scr、eGFR-MDRD。结论　eGFR-MDRD、Cys C 2项指标联合筛查发现真正的DN患者与单纯糖尿病患者的效果好，真实性大且敏感性强。

Analysis of the clinical significance of eGFR-MDRD and Cys C on early diagnosis of diabetic nephropathy

Abstract: Objective The study aimed to explore the clinical application value of serum cystatin C (Cys C) and glomerular filtration rate (eGFR-cys) estimated by Cys C on early diagnosis of diabetic nephropathy (DN). Methods 126 patients with type II diabetes were divided into a simple diabetes group and a diabetic nephropathy group according to their urinary albumin excretion rate. Fasting blood glucose (FBG), 2h postprandial blood glucose (2hPBG), hemoglobin A1c (HbA1c), 24h urine protein quantitation (24h UPQ), serum creatinine (Scr), blood urea nitrogen (BUN), cystatin C (Cys C) of the patients were determined; furthermore, eGFRs of the patients were estimated by simplified MDRD equation, and eGFR-cys was estimated by the CHINAcys equation. Diagnostic values of each of the indicators were analyzed by using the receiver operator characteristic curve (ROC) of the subjects. Results As compared with the simple diabetes group, the diabetic nephropathy group had significantly increased 24h UPQ, BUN, Scr, and Cys C and significantly decreased eGFR-MDRD and eGFR-cys (P<0.01). Cys C and eGFR-cys were correlated with 24h UPQ, Bun, Scr, and eGFR-MDRD; Cys C has the highest correlation coefficient with eGFR-MDRD, (-0.681). AUC of 24h UPQ, Cys C, and eGFR-cys were higher than 0.75, indicating that 24h UPQ, Cys C, and eGFR are more effective in diagnosing DN than BUN, Scr, and eGFR-MDRD. When intercepting at eGFR-cys <60 ml·min-1(173m2)-1] and Cys C >0.98 mg/L, the sensitivity and Youden index of eGFR-MDRD in conjunction with Cys C in diagnosing DN were 87.35% and 0.710, respectively; which were higher than those of BUN, Cys C, Scr, and eGFR-MDRD. Conclusion Adopting eGFR-MDRD in conjunction with Cys C in screening true DN and simple diabetes is effective and high in accuracy and sensitivity.