Background

The inclusion of race in equations to estimate the glomerular filtration rate (GFR) has become controversial. Alternative equations that can be used to achieve similar accuracy without the use of race are needed.

Methods

In a large national study involving adults with chronic kidney disease, we conducted cross-sectional analyses of baseline data from 1248 participants for whom data, including the following, had been collected: race as reported by the participant, genetic ancestry markers, and the serum creatinine, serum cystatin C, and 24-hour urinary creatinine levels.

Results

Using current formulations of GFR estimating equations, we found that in participants who identified as Black, a model that omitted race resulted in more underestimation of the GFR (median difference between measured and estimated GFR, 3.99 ml per minute per 1.73 m² of body-surface area; 95% confidence interval [CI], 2.17 to 5.62) and lower accuracy (percent of estimated GFR within 10% of measured GFR [P₁₀], 31%; 95% CI, 24 to 39) than models that included race (median difference, 1.11 ml per minute per 1.73 m²; 95% CI, −0.29 to 2.54; P₁₀, 42%; 95% CI, 34 to 50). The incorporation of genetic ancestry data instead of race resulted in similar estimates of the GFR (median difference, 1.33 ml per minute per 1.73 m²; 95% CI, −0.12 to 2.33; P₁₀, 42%; 95% CI, 34 to 50). The inclusion of non-GFR determinants of the serum creatinine level (e.g., body-composition metrics and urinary excretion of creatinine) that differed according to race reported by the participants and genetic ancestry did not eliminate the misclassification introduced by removing race (or ancestry) from serum creatinine–based GFR estimating equations. In contrast, the incorporation of race or ancestry was not necessary to achieve similarly statistically unbiased (median difference, 0.33 ml per minute per 1.73 m²; 95% CI, −1.43 to 1.92) and accurate (P₁₀, 41%; 95% CI, 34 to 49) estimates in Black participants when GFR was estimated with the use of cystatin C.

Conclusions

The use of the serum creatinine level to estimate the GFR without race (or genetic ancestry) introduced systematic misclassification that could not be eliminated even when numerous non-GFR determinants of the serum creatinine level were accounted for. The estimation of GFR with the use of cystatin C generated similar results while eliminating the negative consequences of the current race-based approaches. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.)

中文翻译：

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CKD 患者的种族、遗传祖先和肾功能评估

背景

在估算肾小球滤过率 (GFR) 的方程中加入种族已成为争议。需要可用于在不使用种族的情况下实现类似精度的替代方程。

方法

在一项涉及患有慢性肾病的成年人的大型全国性研究中，我们对 1248 名参与者的基线数据进行了横断面分析，这些参与者的数据包括以下内容：参与者报告的种族、遗传祖先标记和血清肌酐、血清胱抑素 C 和 24 小时尿肌酐水平。

结果

使用当前 GFR 估计方程的公式，我们发现在确定为黑人的参与者中，忽略种族的模型导致对 GFR 的低估（测量和估计 GFR 之间的中位数差异，每 1.73 m ²身体每分钟 3.99 毫升 -表面积；95% 置信区间 [CI]，2.17 到 5.62）和更低的准确度（估计 GFR 的百分比在测量 GFR 的 10% [P ₁₀ ] 内，31%；95% CI，24 到 39）比包括种族的模型（中位数差异，每 1.73 m ²每分钟 1.11 ml ；95% CI，-0.29 至 2.54；P 10，42 _%；95% CI，34 至 50）。结合遗传血统数据而不是种族导致对 GFR 的相似估计（中位数差异，每 1.73 m ^{2每分钟 1.33 ml}; 95% CI，-0.12 至 2.33；P ₁₀ , 42%; 95% CI，34 至 50）。包括根据参与者报告的种族和遗传血统而不同的血清肌酐水平的非 GFR 决定因素（例如，身体成分指标和尿中肌酐排泄量）并不能消除通过消除种族（或血统）引入的错误分类来自基于血清肌酐的 GFR 估计方程。相比之下，种族或血统的结合对于实现类似的统计无偏（中位数差异，每 1.73 m ²每分钟 0.33 ml ；95% CI，-1.43 至 1.92）和准确（P 10，41 _%；95%当使用胱抑素 C 估计 GFR 时，黑人参与者的 CI，34 至 49）估计值。

结论

使用血清肌酐水平来估计没有种族（或遗传血统）的 GFR 引入了系统性错误分类，即使考虑到血清肌酐水平的许多非 GFR 决定因素也无法消除。使用胱抑素 C 估计 GFR 产生了类似的结果，同时消除了当前基于种族的方法的负面影响。（由国家糖尿病、消化和肾脏疾病研究所等资助。）