title: Fibroblast growth factor 23 and Klotho serum levels in healthy children.
abstract: Data for fibroblast growth factor 23 (FGF23) and particularly for Klotho in healthy children are limited. We aimed to investigate the relationship between FGF23 and Klotho with age and TmP/GFR and to evaluate parameters that might affect FGF23 and Klotho. In 159 healthy children (82 boys) with a mean±SD age of 8.78±3.47years we measured FGF23 (intact FGF23/iFGF23 and C-terminal FGF23/cFGF23) and soluble aKlotho serum levels by ELISA. Mean±SD value for cFGF23, was 51.14±12.79 RU/ml whereas median (range) values for iFGF23 and Klotho were 35 (8.8, 120) pg/ml and 1945 (372, 5866) pg/ml respectively. Neither FGF23 nor Klotho were significantly associated with age. Pubertal children had higher Klotho than prepubertal (p<0.05), and girls had higher levels of cFGF23 (p<0.05) and Klotho (p<0.001) than boys. Serum phosphate and TmP/GFR were positively associated with cFGF23 (p<0.01 and p<0.001), iFGF23 (p<0.05 and p<0.001) and Klotho (p<0.05 and p<0.01). Klotho was positively correlated with IGF-I (p<0.0001) and 1,25 (OH)2 vitamin D (p<0.05). In this study we provide data on cFGF23, iFGF23, and Klotho measured simultaneously in healthy children. The positive association of serum phosphate and TmP/GFR with FGF23 and Klotho suggests that they have a counterregulatory effect on phosphate homeostasis. The strong association of Klotho with IGF-I could indicate a role of Klotho in linear growth through phosphate regulation, but further studies are required.
authors.affiliation: Department of Pediatrics, Medical School, University of Patras, Rio, Greece. Electronic address: gkentzid@hotmail.com.
authors.forename: Despoina
authors.initials: D
authors.lastname: Gkentzi
authors.affiliation: Pediatric Endocrine Unit, Department of Pediatrics, Medical School, University of Patras, Rio, Greece.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Efthymiadou
authors.affiliation: Pediatric Endocrine Unit, Department of Pediatrics, Medical School, University of Patras, Rio, Greece.
authors.forename: Dimitra
authors.initials: D
authors.lastname: Kritikou
authors.affiliation: Pediatric Endocrine Unit, Department of Pediatrics, Medical School, University of Patras, Rio, Greece.
authors.forename: Dionisios
authors.initials: D
authors.lastname: Chrysis
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000097:blood*; D005966:Glucuronidase / Q000097:blood*; D006262:Health; D006801:Humans; D007334:Insulin-Like Growth Factor I; D000090265:Klotho Proteins; D008297:Male; D011627:Puberty / Q000097:blood
chemical_list: C000717427:FGF23 protein, human; D005346:Fibroblast Growth Factors; D007334:Insulin-Like Growth Factor I; D000089703:Fibroblast Growth Factor-23; D005966:Glucuronidase; D000090265:Klotho Proteins
keywords: Children; Fibroblast growth factor 23; Klotho; Phosphate