Variables of interest to predict glomerular filtration rate in preterm newborns in the first days of life
Measurement of neonatal renal function is challenging, and accurate, easy-to-use markers to estimate glomerular filtration rate (eGFR) are lacking. This study aimed to evaluate principal determinants of GFR in neonates and develop a predictive equation.
GFR was measured, using single injection inulin clearance, at median day 3 of life in 48 newborns. Associations of clearance with height, gestational age, weight, creatinine, and cystatin C were explored and a multivariable model to estimate GFR developed. We also evaluated preexisting GFR equations (Schwartz, Zappitelli, combined Zappitelli).
Forty-four clearances were measured, 36 very preterm neonates (28–32 weeks); 5 extremely preterm (< 28 weeks), and 3 term newborns. No patient presented acute renal insufficiency. Median inulin clearance in preterm infants was 18.83 ml/min/1.73 m2 (IQ 15.29; 24.99). Inulin clearance correlated with weight (ρ 0.74), gestational age (ρ 0.72), height (ρ 0.49), and creatinine (ρ − 0.42), but not cystatin C. In the multivariable model, predicted GFR equation was 2.32* (weight (g))0.64/(creatinine (mcmol/l))0.62. Mean error in predicting clearance was − 0.8 ml/min/1.73 m2 (− 3.0–1.4) ranging from − 14.9 to 13.3 ml/min/1.73 m2. Mean prediction error with Zappitelli and combined Zappitelli equations were 28.5 ml/min/1.73 m2 (95% CI 24.6–32.3) and 28.3 ml/min/1.73 m2 (95% CI 24.9–31.7), respectively, and 2 ml/min/1.73 m2 (95% CI − 0.6–4.6) for Schwartz equation.
Weight and gestational age are crucial determinants of GFR in neonates. The Zappitelli models were not validated in our population. Our predictive model and Schwartz models performed better. Our model should be evaluated in another preterm population, particularly in those presenting renal insufficiency.
KeywordsGlomerular filtration rate Preterm Newborns Estimated glomerular filtration rate
Glomerular filtration rate
Estimated glomerular filtration rate
We thank Dr. Riccardo Pfister and the neonatology unit of Geneva Children Hospital for helping the inclusion of infants and the Research Platform of Geneva Children Hospital for the technical support. We are indebted to Dolores Mosig, Pediatric Nephrology Laboratory, in Lausanne for the biological measurements of inulin. A final thanks to Mme Rosemary Sudan for translation and proofreading of the text.
Dr. Wilhelm-Bals and Prof. Parvex conceptualized and designed the study, collected the data carried out the initial analyses, drafted the initial manuscript, and reviewed and critically revised the manuscript for intellectual content.
C. Combescure designed the data collection instruments, carried out the statistical analyses, and reviewed and revised the manuscript.
Y. Daali designed the pharmacological analyses, carried out the pharmacological analyses, and reviewed and revised the manuscript.
Dr. Chehade coordinated and supervised data collection and reviewed and revised the manuscript.
All Authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
Von Meissner Grant, PRD for clinical research Grant, Geneva University Hospital, grant number CGR 7121.
Compliance with ethical standards
Conflict of interest
The authors have no conflicts of interest relevant to this article to disclose. The results presented in this paper have not been published previously in whole or part, except in abstract form.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
The authors have no financial relationships relevant to this article to disclose.
- 1.Jetton JG, Guillet R, Askenazi DJ, Dill L, Jacobs J, Kent AL, Selewski DT, Abitbol CL, Kaskel FJ, Mhanna MJ, Ambalavanan N, Charlton JR, Collaborative NK (2016) Assessment of worldwide acute kidney injury epidemiology in neonates: design of a retrospective cohort study. Front Pediatr 4:68CrossRefGoogle Scholar
- 24.Leake RD, Trygstad CW, Oh W (1976) Inulin clearance in the newborn infant: relationship to gestational and postnatal age. Pediatr Res 10:759–762Google Scholar