Introduction of serum creatinine for detecting chronic kidney disease in pediatric lifestyle-related disease screening

As most children with stage 3–5 chronic kidney disease (CKD) in Japan present with nonglomerular disease, its detection is difficult during annual urinalysis conducted in school. Since 2020, in Uwajma city, Japan, to screen pediatric CKD, the practice of measuring serum creatinine (Cr) levels was introduced in addition to the pediatric lifestyle-related disease checkup, which involved measuring total and HDL cholesterol levels in fourth-grade elementary school children. Decisions regarding positive screening were made according to the Cr-based estimated glomerular filtration rate (Cr-eGFR). Similar screening practice was initiated in Ozu City in 2022 for fourth graders in elementary school (E4) and first graders in junior high school (J1). Till date, 1,900 E4 and 352 J1 have been screened. The criterion for positive screening was Cr-eGFR level of