Background: Renal inulin clearance is the gold standard for glomerular filtration rate (GFR), but is compromised by problems of collecting urine samples in children, especially those <6 years of age or with a bladder dysfunction. Therefore, we should utilize the serum creatinine (Cr)-based estimated GFR (eGFR), measuring serum Cr by enzymatic method. The updated Schwartz formulae were reported by enzymatic Cr instead of by the Jaffe method in American children aged 1-16 years old. We believe it would be better to determine serum Cr-based eGFR by the enzymatic method in Japanese children for evaluation of renal function.
Methods: Serum Cr-based eGFR was determined by measuring inulin clearance and serum Cr level in 76 pediatric chronic kidney disease (CKD) patients (49 males and 27 females) aged 2-11 years with no underlying disease that would affect renal function.
Results: We showed the inulin clearance by expression of the body length/serum Cr ratio in pediatric CKD patients, which resulted in the equation: [Formula: see text]. Additionally, we suggest the following serum Cr-based eGFR formula passing through the origin: [Formula: see text], because it is simple and easy to remember, thus making it clinically useful.
Conclusion: The new eGFR formula derived from body length and serum Cr level is applicable for clinical screening of renal function in Asian as well as Japanese children aged between 2 and 11 years old.