The effect of GH treatment on serum FGF23 and Klotho in GH-deficient children. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: Efthymiadou, Alexandra; Kritikou, Dimitra; Mantagos, Stefanos; Chrysis, Dionisios
• Is Part Of: European journal of endocrinology. Volume 174:Issue 4(2016)
• Page Start: 473
• Page End: 479
• Publication Date: 2016-04
• Subjects: Endocrinology -- Periodicals; 616.4005
• DOI: 10.1530/EJE-15-1018
• Languages: English
• ISSNs: 0804-4643

Abstract

Abstract : Background: Normal phosphate homeostasis is essential for normal linear growth. The phosphaturic fibroblast growth factor 23 (FGF23)/Klotho axis is a major regulator of phosphate homeostasis; therefore, an intact FGF23/Klotho axis is important for normal linear growth. On the other hand, GH/IGF1 axis has opposing effects on phosphate homeostasis, but the underline mechanisms remain unclear. Aim: The main objective of this study was to investigate the possible interactions of FGF23 and its co-receptor Klotho, with growth hormone (GH)/IGF1 axis in the regulation of phosphate metabolism in GH-deficient children under GH treatment. Methods: We studied 23 GH-deficient children, before and 3 months after the onset of GH treatment. Anthropometry and assessment of biochemical parameters were performed, as well as measurement of FGF23 (intact FGF23/iFGF23 and C-terminal FGF23/cFGF23) and soluble α-Klotho (sKlotho) levels. Results: After 3 months on GH treatment, the elevation of serum phosphate and TmPO4/GFR ( P <0.0001 and P <0.01 respectively) was accompanied by a significant increase in cFGF23 ( P <0.01), iFGF23 ( P <0.0001), sKlotho ( P <0.0001) and IGF1 ( P <0.0001). Serum phosphate and TmPO4/GFR were positively associated with iFGF23 ( P <0.01 and P <0.05) and IGF1 ( P <0.05 and P <0.05). iFGF23 levels were positively correlated with sKlotho ( P <0.001), IGF1 ( P <0.0001) and height SDS ( P <0.0001), whereas sKlotho was positively associated with IGF1 ( P <0.0001) and height SDS ( P <0.001). Conclusion: The increase in serum phosphate, which we found in GH-deficient children under GH treatment, is not associated with suppression but rather than with upregulation of the phosphaturic FGF23/Klotho axis.