Smeets Nori J L, IntHout Joanna, van der Burgh Maurice J P, Schwartz George J, Schreuder Michiel F, de Wildt Saskia N
Department of Pharmacology and Toxicology, Radboud Institute of Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
Intensive Care and Department of Pediatric Surgery, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands.
J Am Soc Nephrol. 2022 Jul;33(7):1277-1292. doi: 10.1681/ASN.2021101326. Epub 2022 Apr 26.
The evidence from individual studies to support the maturational pattern of GFR in healthy, term-born neonates is inconclusive. We performed an individual participant data (IPD) meta-analysis of reported measured GFR (mGFR) data, aiming to establish neonatal GFR reference values. Furthermore, we aimed to optimize neonatal creatinine-based GFR estimations.
We identified studies reporting mGFR measured by exogenous markers or creatinine clearance (CrCL) in healthy, term-born neonates. The relationship between postnatal age and clearance was investigated using cubic splines with generalized additive linear mixed models. From our reference values, we estimated an updated coefficient for the Schwartz equation (eGFR [ml/min per 1.73 m]=(k×height [cm])/serum creatinine [mg/dl]).
Forty-eight out of 1521 screened articles reported mGFR in healthy, term-born neonates, and 978 mGFR values from 881 neonates were analyzed. IPD were available for 367 neonates, and the other 514 neonates were represented by 41 aggregated data points as means/medians per group. GFR doubled in the first 5 days after birth, from 19.6 (95% CI, 14.7 to 24.6) to 40.6 (95% CI, 36.7 to 44.5) ml/min per 1.73 m, and then increased more gradually to 59.4 (95% CI, 45.9 to 72.9) ml/min per 1.73 m by 4 weeks of age. A coefficient of 0.31 to estimate GFR best fitted the data.
These reference values for healthy, term-born neonates show a biphasic increase in GFR, with the largest increase between days 1 and 5. Together with the re-examined Schwartz equation, this can help identify altered GFR in term-born neonates. To enable widespread implementation of our proposed eGFR equation, validation in a large cohort of neonates is required.
个体研究中支持健康足月新生儿肾小球滤过率（GFR）成熟模式的证据尚无定论。我们对已报道的实测GFR（mGFR）数据进行了个体参与者数据（IPD）荟萃分析，旨在建立新生儿GFR参考值。此外，我们旨在优化基于肌酐的新生儿GFR估算值。
我们检索了报告健康足月新生儿通过外源性标志物或肌酐清除率（CrCL）测定mGFR的研究。使用三次样条和广义相加线性混合模型研究出生后年龄与清除率之间的关系。根据我们的参考值，我们估算了施瓦茨方程的更新系数（估算肾小球滤过率[eGFR，ml/min per 1.73 m]=(k×身高[cm])/血清肌酐[mg/dl]）。
在1521篇筛选文章中，有48篇报告了健康足月新生儿的mGFR，分析了来自881例新生儿的978个mGFR值。367例新生儿有个体参与者数据，另外514例新生儿由41个汇总数据点表示，为每组的均值/中位数。出生后前5天GFR翻倍，从19.6（95%CI，14.7至24.6）增至40.6（95%CI，36.7至44.5）ml/min per 1.73 m，然后到4周龄时逐渐增至59.4（95%CI，45.9至72.9）ml/min per 1.73 m。估算GFR的系数0.31最符合数据。
这些健康足月新生儿的参考值显示GFR呈双相增加，出生后第1天至第5天增加最大。连同重新审视的施瓦茨方程，这有助于识别足月新生儿GFR的改变。为使我们提出的估算肾小球滤过率（eGFR）方程得以广泛应用，需要在大量新生儿队列中进行验证。
