胱抑素C对冠状动脉旁路移植术患者肾功能监测的价值

Value of serum cystatin C in monitoring renal dysfunction after coronary artery bypass grafting

目的对血清胱抑素C（Cys C）作为肾小球滤过率（GFR）指标在监测冠状动脉旁路移植（CABG）患者急性肾功能不全中的价值进行评价。方法对61例非体外循环CABG患者术前1d，术后1、2、4、7d的血清CysC、血肌酐（SCr）、内生肌酐清除率（CCr）和Cockcroft—Gault（CG）公式估计的GFR等进行测定分析，并以CCr为GFR的参考标准对各检测指标进行比较。结果术前各检测指标均在正常范围内，术后各时段CysC与术前比较差异均有统计学意义（P〈0．01或〈0．05），SCr与术前比较差异均无统计学意义（P均〉0．05），CG的变化与GFR相似，但所·有时段与GFR比较差异均有统计学意义（P均〈0．05）。相关分析表明，1／CysC与GFR的相关性和1／SCr、CG公式与GFR的相关性比较，差异均有统计学意义（P〈0．01或〈0．05）。ROC曲线表明，无论以GFR〈60ml／min，还是以GFR〈80ml／min定义为肾功能不全，CysC对诊断CABG术后急性肾功能不全的准确性均高于SCr、CG公式。结论CysC是监测CABG患者术后急性肾功能不全的良好标志物，可替代SCr来评估GFR。

Objective To assess the value of serum cystatin C （Cys C） as a marker of glomerular filtration rate （GFR） in acute renal dysfunction after coronary artery bypass grafting （CABG）. Methods Sixty - one patients undergoing off- pump CABG were studied. Blood samples were collected on day 1 preoperatively and on day 1, 2, 4 and 7 postoperatively to measure Cys C, serum creatinine （SCr）, creatinine clearance rate （CCr） and the estimated GFR according to the Cockcroft -Gault （CG）formula respectively. CCr served as reference method for GFR, and then Cys C, SCr and CG levels were compared. Results The mean values of the preoperative markers were within normal range. Cys C significantly increased postoperatively compared to those preoperatively （ P 〈 0.01 or 〈 0.05 ）. SCr increased postoperatively but there was no significance compared to those preoperatively. CG significantly decreased postoperatively compared to those preoperatively （P 〈 0.05 or 〈 0.01 ）, but the median values were found to be significantly lower than those of GFR （ all P 〈 0.05）. On evaluation of the correlation study for renal function, although significant relationships were found between GFR and 1/Cys C （r = 0. 878, P 〈 0.01 ）, GFR and 1/SCr （r = 0. 702, P 〈 0.01） （ both expressed inverse relationships with GFR）, as well as GFR and CG （r = 0. 731, P 〈 0.05 ） levels, the best correlation of GFR was found with Cys C. Receiver operating curves （ROC） revealed of all markers the area under the curve （AUC） for Cys C was found be greatest in the condition of renal dysfunction was defined as GFR less than 60 ml/ rain （AUC = 0.964） or less than 80 ml/min （AUC = 0. 921 ）. Conclusion Cys C is a good indicator in acute renal dysfunction following CABG, and may be used as surrogate measures for GFR in CABG.