Estimating GFR using serum cystatin C alone and in combination with serum creatinine: A pooled analysis of 3,418 individuals with CKD
Estimating GFR using serum cystatin C alone and in combination with serum creatinine: A pooled analysis of 3,418 individuals with CKD
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DOI：
10.1053/j.ajkd.2007.11.018
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发表时间：
2008-03-01
影响因子：
13.2
通讯作者：
Levey, Andrew S.
中科院分区：
文献类型：
--
作者：
Stevens, Lesley A.;Coresh, Josef;Levey, Andrew S.
背景：血清胱抑素C被提议作为肾小球滤过率（GFR）估计中血清肌酐的潜在替代物。我们报告的发展和评价GFR估计方程使用血清胱抑素C单独和血清胱抑素C，血清肌酐，或两者与人口统计学变量。研究设计：诊断准确性测试。设置和参与者：参与者筛选3慢性肾脏疾病（CKD）的研究在美国（n = 2，980）和法国巴黎的临床人群（n = 438）。参考试验：测量的GFR（mGFR）。指数试验：使用基于单独的血清胱抑素C、血清胱抑素C、血清肌酐或两者与年龄、性别和种族的4个新方程估计的GFR。通过使用线性回归开发了新的方程，并将log GFR作为来自美国研究的三分之二数据的结果。在美国CKD研究的其余三分之一数据中进行了内部验证;在巴黎研究中进行了外部验证。测量：在美国研究中通过使用碘-125-碘酞酸盐的尿清除率测量GFR，在巴黎研究中通过使用铬-51-EDTA测量GFR。结果：平均mGFR为48 mumin/1.73 m2（第5 ~ 95百分位数，15 ~ 95），血清肌酐为2.1 mg/dL，血清胱抑素C为1.8 mg/L。对于新的方程，年龄，性别和种族的系数在血清胱抑素C的方程中是显着的，但2- 4倍小于血清肌酐的方程。新方程中的性能指标在开发和内部和外部验证数据集之间保持一致。对于基于血清胱抑素C单独、血清胱抑素C、血清肌酐或两者水平的方程，估计的GFR在mGFR的30%以内的百分比随年龄、性别和人种的变化分别为81%、83%、85%和89%。单独使用血清半胱氨酸蛋白酶抑制剂C水平的方程产生的估计值在年龄、性别和种族亚组中存在较小的偏差，在包含这些变量的方程中得到了改进。局限性：研究人群主要由慢性肾病患者组成。结论：单独的血清胱抑素C水平提供了GFR估计，其几乎与经年龄、性别和种族校正的血清肌酐水平一样准确，从而提供了一种与肌肉质量无关的替代GFR估计值。包括血清胱抑素C水平与血清肌酐水平、年龄、性别和种族的方程提供了最准确的估计。
Background: Serum cystatin C was proposed as a potential replacement for serum creatinine in glomerular filtration rate (GFR) estimation. We report the development and evaluation of GFR-estimating equations using serum cystatin C alone and serum cystatin C, serum creatinine, or both with demographic variables.Study Design: Test of diagnostic accuracy.Setting & Participants: Participants screened for 3 chronic kidney disease (CKD) studies in the United States (n = 2,980) and a clinical population in Paris, France (n = 438).Reference Test: Measured GFR (mGFR).Index Test: Estimated GFR using the 4 new equations based on serum cystatin C alone, serum cystatin C, serum creatinine, or both with age, sex, and race. New equations were developed by using linear regression with log GFR as the outcome in two thirds of data from US studies. Internal validation was performed in the remaining one third of data from US CKD studies; external validation was performed in the Paris study.Measurements: GFR was measured by using urinary clearance of iodine-125-iothalamate in the US studies and chromium-51-EDTA in the Paris study. Serum cystatin C was measured by using Dade-Behring assay, standardized serum creatinine values were used.Results: Mean mGFR, serum creatinine, and serum cystatin C values were 48 mumin/1.73 m(2) (5th to 95th percentile, 15 to 95), 2.1 mg/dL, and 1.8 mg/L, respectively. For the new equations, coefficients for age, sex, and race were significant in the equation with serum cystatin C, but 2- to 4-fold smaller than in the equation with serum creatinine. Measures of performance in new equations were consistent across the development and internal and external validation data sets. Percentages of estimated GFR within 30% of mGFR for equations based on serum cystatin C alone, serum cystatin C, serum creatinine, or both levels with age, sex, and race were 81%, 83%, 85%, and 89%, respectively. The equation using serum cystatin C level alone yields estimates with small biases in age, sex, and race subgroups, which are improved in equations including these variables.Limitations: Study population composed mainly of patients with CKD.Conclusions: Serum cystatin C level alone provides GFR estimates that are nearly as accurate as serum creatinine level adjusted for age, sex, and race, thus providing an alternative GFR estimate that is not linked to muscle mass. An equation including serum cystatin C level in combination with serum creatinine level, age, sex, and race provides the most accurate estimates.