A new equation to estimate the glomerular filtration rate in children, adolescents and young adults

…the Pottel group in Belgium has provided novel and useful information to assist clinicians and researchers in estimating GFR from serum creatinine. Their approach provides the basic format for screening children, adolescents and young adults for the presence of kidney disease. Background A new estimated glomerular filtration rate (eGFR) equation, designed for isotope dilution mass spectrometry-standardized serum creatinine (Scr), is presented for use in children, adolescent boys and girls and young adults. Methods The new equation, eGFR = 107.3/(Scr/Q), is based on the concept of normalized Scr: Q is the normalization value and is considered as the Scr concentration for the average healthy child, adolescent or young adult of a specific height (L) and is modeled as a height-dependent polynomial of the fourth degree. Results The well-known Schwartz equation [eGFR = kL/Scr, k = 0.413 (Schwartz) or k = 0.373 (Schwartz–Lyon)] for children between 1 and 14 years can be seen as a special case of the new equation for which the Q-polynomial is simplified to a linear equation: Q = 0.0035 × L (cm). The new eGFR equation has been validated in a data set of n = 750 children, adolescents and young adults aged 10–25, against the true GFR (inulin method), and outperforms the selected (but most used) creatinine-based eGFR equations for children, mainly in the healthy GFR region. Conclusions The new Q(height)-eGFR equation serves as an excellent screening tool for kidney disease in 1–25-year-old children, adolescents and young adults.