Serum intact fibroblast growth factor 23 in healthy paediatric population

INTRODUCTION: It is believed that fibroblast growth factor 23 (FGF23) can become an early biomarker of chronic kidney disease progression. Data on FGF23 age dependency are inconsistent. We present the results of the cross-sectional study concerning FGF23 levels in healthy Polish children. MATERIAL AND METHODS: This study was conducted in 121 children aged 0–18 years. Kidney function and intact FGF23 levels in serum were assessed. Differences between age groups and according to gender were analysed. RESULTS: The difference in FGF23 between age groups and according to gender was statistically insignificant. In the youngest and the oldest group, a trend to higher FGF23 levels was observed. FGF23 level in girls tended to be higher than boys, apart from the age group between 1 and 4 years. There was a negative correlation between eGFR and FGF23 (r = −0.26, p < 0.05) – strong in girls (r = −0.38, p < 0.05), but not in boys. In each age group, we found no significant correlation between eGFR and FGF23. CONCLUSIONS: Our study supports the evidence that the FGF23 level in paediatric population is not age or sex dependent. The results can serve as a reference point under clinical conditions and for other studies on the topic.