基于血肌酐和胱抑素C的肾小球滤过率计算方程对老年慢性肾脏病肾功能评估的价值和意义

Assessment of equation for glomerular filtration rate estimation based on serum creatine and cystatin C in chronic kidney disease of old patients

目的探讨现有4种基于血肌酐的肾小球滤过率计算方程在评估老年慢性肾脏病患者的肾小球滤过率的价值,并开发基于胱抑素C的计算肾小球滤过率的方程。方法测定267例2008年1月至2009年4月在该科住院的老年患者(年龄>50岁,男性114例,女性153例,)血清胱抑素C水平,同时应用放射性核素标记物99mTc-DTPA测定肾小球滤过率(tGFR),以Gates法准确确定受试者GFR。血清胱抑素C(CysC)采用颗粒增强透射免疫比浊法,通过多元回归推算出基于血清胱抑素C计算肾小球滤过率的方程(eGFR),并与Cockcroft-Gault公式、MDRD公式、改良MDRD公式和基于我国人口学资料改良的简化MDRD公式计算的eGFR比较,(依次以eGFR1、eGFR2、eGFR3、eGFR4表示),评估现有4种的肾小球滤过率计算方程及基于血清胱抑素C计算肾小球滤过率的方程对老年慢性肾脏病患者的价值。结果eGFR1、eGFR2、eGFR3、eGFR4、eGFR均与tGFR呈正相关,相关系数为0.74、0.74、0.47、0.75、0.68,组内相关系数为0.80、0.74、0.30、0.79、0.65(P<0.001),基于血清胱抑素C计算肾小球滤过率的直线回归方程为eGFR=76.75-1.03×血清胱抑素-0.59×年龄+0.23×血清清蛋白(血清胱抑素:mg/L,年龄:岁,血清清蛋白:g/L),Bland-Altman回归分析显示eGFR1、eGFR4的偏差度和准确度及准确率均较eGFR2、eGFR3和eGFR良好。eGFR4落在tGFR±15%、±30%和±50%范围内的患者百分数反映了eGFR4与tGFR符合程度(准确)性,分别为29.4.8%、39.43%和64.4%。结论现有四种的肾小球滤过率计算方程中,基于我国人口学资料改良的简化MDRD公式对老年慢性肾脏病患者肾小球滤过率评估较准确,偏差度小,准确度及准确率高。基于血清胱抑素C的计算方程能用于老年慢性肾脏病患者肾小球滤过率,以基于我国人口学资料改良的MDRD公式比较无明显优势。

[ Objectives ] To evaluate the four equation for glomerular filtration rate estimation based on serum creatine in chronic kidney disease of old patients,and to develop equation for glomerular filtration rate estimation base on serum cystatin C （cysC）. [ Methods ] 267 old inpatients from January 2008 to April 2009 were recruited in the study.（114 male/153 female, age 〉50 years）. Serum eysC was determined by particle-enhanced turbidimetric immunoassay （PETIA）, tGFR was estimated using the renal dynamic imaging method （modified Gate＇s method） with ^99mTc-diethylene triamine pentaacetic acid （^99mTc-DTPA）. Equation for glomerular filtration rate （eGFR） estimation based on serum cystatin C was calculated by multiple regression. Compared with glomerular filtration rate estimated simultaneously using four methods： Cockcroft-Gault method （eGFR1）; Modification of Diet in Renal Disease （MDRD） study equation （eGFR2）; the modified abbreviated MDRD equation （eGFR3）; the modified abbreviated MDRD equation based on demography data of chinese. To evaluate the four equation for glomerular filtration rate estimation based on erum cystatin C in chronic kidney disease of old patients. [Results] eGFR1, eGFR2, eGFR3, eGFRg, eGFR showed positive correlation with tGFR, the correlation coefficient are 0.74,0.74,0.47,0.75,0.65, respectively, intraclass correlation coefficient are 0.80, 0.74, 0.30, 0.79, 0.65（P〈0.001 ）, linear regression equation for glomerular filtration rate estimation based on serum cystatin C is that eGFR=76.75-1.03 × cystatin C -0.59 × age＋ 0.23×Alb （cystatin C： rag/L, age： year,Alb： g/L）,Bland-Altman regression analysis showed that deviation, precision and accuracy of eGFR1 ,eGFR4 are better than eGFR2,eGFR3 and eGFR. For eGFR4, the corresponding accuracy rose to 29.4.8%, 39.43% and 64.4%, respectively. [ Conclusions ] The modified abbreviated MDRD equation according to demography data of chinese was better than the others,the deviation was tiny, the precision and accuracy were much higher than the others. Our results indicated that the GFR estimation based on serum cystatin C was not better than the modified abbreviated MDRD equation based on demography data of chinese in our patient group.