Abstract:Objective To explore the changes in levels of Klotho and fibroblast growth factor 23 (FGF23) in children with short stature and their correlations with the growth hormone (GH)-insulin-like growth factor 1 (IGF1) axis.Methods The 67 children in the pediatric health care clinic of Hebei General Hospital from March 2021 to November 2021 were included as the study group, and were divided into the growth hormone deficiency (GHD) group and the idiopathic short stature (ISS) group, with 26 and 41 cases in each group, respectively. Another 29 children with normal stature who underwent routine physical examinations at the same pediatric health care clinic during the same period were selected as the control group. Serum levels of Klotho, FGF23, IGF1, insulin-like growth factor binding protein 3 (IGFBP3), calcium, 1,25-dihydroxyvitamin D3, and phosphates were measured and compared between the study group and the control group.Results The height standard deviation score (SDS) and the weight SDS were different among the groups (P < 0.05), where those in the GHD group and the ISS group were lower than those in the control group (P < 0.05). There was no difference in age, sex composition, sexual maturity rating and BMI-SDS among the groups (P > 0.05). The levels of IGF1, IGFBP3, Klotho and FGF23 in the GHD group were lower than those in the ISS group and the control group (P < 0.05). The Spearman correlation analysis showed that the level of Klotho was positively correlated with the levels of IGF1, IGFBP3, FGF23 and phosphates (rs = 0.628, 0.512, 0.495 and 0.266, all P < 0.05). The level of FGF23 was in positive correlation with the levels of IGF1, IGFBP3 and phosphates (rs = 0.440, 0.484 and 0.277, all P < 0.05).Conclusions The levels of Klotho and FGF23 are low in children with GHD. Klotho and FGF23 play a significant role in linear growth in children with GHD by participating in the regulation of the GH-IGF1 axis, and they are important in regulating serum phosphate homeostasis in children with short stature.