胱蛋白酶抑制素C对糖尿病合并肾功能不全患者对比剂诱导的急性肾损伤的早期诊断价值

Value of plasma cystatin C in early diagnosis of contrast induced acute kidney injury in diabetic patients complicated with renal dysfunction

目的 探讨血浆胱蛋白酶抑制素C （CysC）对糖尿病合并肾功能不全患者对比剂诱导的急性肾损伤（CIAKI）的早期诊断价值.方法 连续选择2009年1月至2010年7月于首都医科大学附属北京安贞医院就诊的冠状动脉粥样硬化性心脏病（冠心病）合并糖尿病及肾功能不全,拟行冠状动脉造影及支架置入术的患者.检测术前血清肌酐、血糖、血脂、术后48 ～ 72 h血清肌酐水平,术前、术后24 h血浆CysC水平,评价CysC对糖尿病合并肾功能不全患者CIAKI的早期诊断价值.结果 入选患者122例,根据是否发生CIAKI分成CIAKI组（21例）和无CIAKI组（101例）.CIAKI组与无CIAKI组年龄、尿素氮、肾小球滤过率、肾小球滤过率＜60 ml/（min· 1.73 m2）者占比、冠状动脉病变数以及对比剂使用量比较[（67±11）岁比（59±10）岁,（8.6 ±2.1） mmol/L比（7.4±0.9）mmol/L,（62±17） mL/（min·1.73 m2）比（71±14） ml/（min· 1.73 m2）,61.9％ （13/21）比35.6％ （36/101）,1支：19.0％ （4/21）比35.6％（36/101）,2支：38.1％ （8/21）比49.5％ （50/101）,≥3支：42.9％ （9/21）比14.9％ （15/101）,（210 ±55） ml比（178±47）ml],差异均有统计学意义（均P＜0.05）.术前,CIAKI组血清肌酐水平明显高于无CIAKI组[（108 ±21） μmol/L比（99 ±9） μmol/L,P＜0.05],而CysC水平2组比较差异无统计学意义（P＞0.05）.术后,CIAKI组血清肌酐、CysC水平明显高于术前和无CIAKI组术后[（120±27） μmol/L比（108±21）、（102±12） μmol/L,（567±187） μg/L比（468±176）、（454±180）μg/L],差异有统计学意义（P＜0.05）;无CIAKI组术后CysC水平明显高于术前[（454±180）μg/L比（413±158） μg/L,P＜0.05],但血清肌酐水平与术前比较差异无统计学意义（P =0.070）.Pearson检验表明,基线时血清肌酐水平与CysC明显相关（r=0.554,P＜0.01）.术前及术后24 h血浆CysC水平的受试者工作特征曲线下面积分别为0.605（95％置信区间：0.464～0.745,P=0.136）和0.663（95％置信区间：0.541～0.785,P=0.020）.CysC相对升高≥25％诊断CIAKI的敏感度和特异度分别为0.905和0.782,阴性预测价值97.5％.结论 血浆CysC可以作为CIAKI的早期诊断标志物,阴性诊断价值更大。

Objective To evaluate the value of plasma cystatin C （CysC） in early diagnosis of contrast induced acute kidney injury （CIAKI） in diabetic patients complicated with renal dysfunction.Methods Coronary heart disease patients with diabetes and renal dysfunction who underwent coronary angiography or stent implantation from January 2009 to July 2010 were enrolled.The baseline serum creatinine （SCr） , glucose and lipids were measured, the SCr was measured again at 48-72 hours after procedure;the plasma CysC levels before and 24 h after procedure were detected and the value of CysC in early diagnosis of CIAKI was evaluated.Results Totally 122 patients were enrolled and divided into CIAKI group （21 cases） and non-CIAKI group （101 cases）.The age, urea, glomerular filtration rate, proportion of patients with glomerular filtration rate 〈60 ml/（min · 1.73 m2）, the number of coronary artery lesions and contrast material usage in CIAK group were significantly different from those in non-CIAKI group [（67 ± 11） years vs （59 ± 10） years;（8.6 ±2.1） mmol/L vs （7.4 ±0.9） mmol/L;（62 ± 17） ml/（min · 1.73 m2） vs （71 ± 14） ml/（min · 1.73 m2）;61.9% （13/21） vs 35.6% （36/101）;single vessel disease： 19.0% （4/21） vs 35.6% （36/101）, double vessels disease： 2 branchs lesion： 38.1% （8/21） vs 49.5% （50/101）, ≥ 3 vessels disease： 42.9% （9/21） vs 14.9% （15/101）;（210 ±55） ml vs （178±47） ml] （P〈0.05）.The baseline SCrin CIAKI group was significantly higher than that in non-CIAKI group [（108 ± 21） μmol/L vs （99 ± 9） μmol/L] （P 〈0.05） , while the CysC level had no significant difference between the two groups （P 〉 0.05）.The levels of Scr and CysC in CIAKI group after operation were significantly higher than those before operation and those in non-CIAKI group after operation [（120 ±27） μmol/L vs （108 ±21）, （102 ± 12） μmol/L, （567 ± 187） μg/L vs （468 ± 176）, （454 ± 180） μg/L] （P 〈 0.05）;the post-operative CysC level was significantly higher than preoperative level in non-CIAKI group [（454 ± 180） μg/L vs （413 ± 158） μg/L], but Scr showed no statistical difference after operation （P =0.070）.The Pearson analysis showed that the baseline Scr was positively correlated with post-operative CysC level （r =0.554, P 〈 0.01）.The area under receiver operating characteristic curve of plasma CysC at baseline and after procedure was 0.605 （95% confidence interval： 0.464-0.745, P =0.136） and 0.663 （95% confidence interval： 0.541-0.785, P =0.020）.The sensitivity, specificity and negative predictive value of CysC in diagnosing CIAKI were 0.905, 0.782 and 97.5% with increasing by ≥ 25% than baseline as cut off value.Conclusion Plasma CysC might be an early biomarker for diagnosis of CIAKI with high negative predictive value.