N E Bakker1, J van Doorn1, J S Renes1, G H Donker1, A C S Hokken-Koelega1. 1. Dutch Growth Research Foundation (N.E.B., A.C.S.H.-K.), 3016 AH Rotterdam, The Netherlands; Department of Pediatrics (N.E.B., J.S.R., A.C.S.H.-K.), Subdivision of Endocrinology, Erasmus Medical Center/Sophia Children's Hospital, 3000 DR Rotterdam, The Netherlands; and Department of Clinical Chemistry and Haematology (J.v.D., G.H.D.), Laboratory of Endocrinology and Department of Medical Genetics, Section of Metabolic Diseases, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands.
Abstract
CONTEXT: Children with Prader-Willi syndrome (PWS) attain high-serum immunoreactive IGF-1 levels during a standard-dose GH treatment, which leads to concern, but lowering the dose deteriorates their body composition. OBJECTIVE: The objective of the study was to evaluate serum IGF-1, IGF binding protein (IGFBP)-3, and acid-labile subunit (ALS) levels, complex formation, and IGF bioactivity in GH-treated PWS children. DESIGN: This was a cross-sectional study. SETTING: The setting of the study was a Dutch PWS cohort. PARTICIPANTS: Forty GH-treated PWS children compared with 41 age- and sex-matched healthy controls participated in the study. INTERVENTIONS: Interventions included GH treatment (1.0 mg/m(2) · d = ∼0.035 mg/kg · d). MAIN OUTCOME MEASURES: Serum IGF-1, IGFBP-3, and ALS levels, complex formation, and IGF bioactivity by IGF-1 receptor kinase activation assay were measured. RESULTS: Serum IGF-1, IGFBP-3, and ALS levels and IGF-1 to IGFBP-3 ratio were significantly higher in GH-treated PWS children than in healthy controls. The 150-kDa ternary complex formation was, however, also significantly higher than in controls, indicating that most of serum IGF-1 is sequestered in the ternary 150-kDa complex with ALS and IGFBP-3. Young GH-treated PWS children [median (interquartile range) aged 5.2 (4.3-7.2) y] exhibited higher serum IGF bioactivity than controls, but no difference was observed in IGF bioactivity between older GH-treated PWS children, aged 14.9 (13.8-16.2) years, and controls. The proportion of IGF bioactivity of total serum IGF-1 was, however, lower in GH-treated PWS children than in controls. Serum immunoreactive IGF-1 levels did not correlate with IGF bioactivity in GH-treated children with PWS, in contrast to a strong positive correlation in healthy controls. CONCLUSIONS: In GH-treated PWS children, most serum IGF-1 is sequestered in the 150-kDa complex. Higher IGF bioactivity was found only in young GH-treated PWS children and not in the older ones. IGF bioactivity during GH showed a wide variation, and there was a disrupted correlation with immunoreactive IGF-1 levels, which makes immunoreactive IGF-1 levels an inappropriate indicator for GH dosing in PWS children.
CONTEXT: Children with Prader-Willi syndrome (PWS) attain high-serum immunoreactive IGF-1 levels during a standard-dose GH treatment, which leads to concern, but lowering the dose deteriorates their body composition. OBJECTIVE: The objective of the study was to evaluate serum IGF-1, IGF binding protein (IGFBP)-3, and acid-labile subunit (ALS) levels, complex formation, and IGF bioactivity in GH-treated PWSchildren. DESIGN: This was a cross-sectional study. SETTING: The setting of the study was a Dutch PWS cohort. PARTICIPANTS: Forty GH-treated PWSchildren compared with 41 age- and sex-matched healthy controls participated in the study. INTERVENTIONS: Interventions included GH treatment (1.0 mg/m(2) · d = ∼0.035 mg/kg · d). MAIN OUTCOME MEASURES: Serum IGF-1, IGFBP-3, and ALS levels, complex formation, and IGF bioactivity by IGF-1 receptor kinase activation assay were measured. RESULTS: Serum IGF-1, IGFBP-3, and ALS levels and IGF-1 to IGFBP-3 ratio were significantly higher in GH-treated PWSchildren than in healthy controls. The 150-kDa ternary complex formation was, however, also significantly higher than in controls, indicating that most of serum IGF-1 is sequestered in the ternary 150-kDa complex with ALS and IGFBP-3. Young GH-treated PWSchildren [median (interquartile range) aged 5.2 (4.3-7.2) y] exhibited higher serum IGF bioactivity than controls, but no difference was observed in IGF bioactivity between older GH-treated PWSchildren, aged 14.9 (13.8-16.2) years, and controls. The proportion of IGF bioactivity of total serum IGF-1 was, however, lower in GH-treated PWSchildren than in controls. Serum immunoreactive IGF-1 levels did not correlate with IGF bioactivity in GH-treated children with PWS, in contrast to a strong positive correlation in healthy controls. CONCLUSIONS: In GH-treated PWSchildren, most serum IGF-1 is sequestered in the 150-kDa complex. Higher IGF bioactivity was found only in young GH-treated PWSchildren and not in the older ones. IGF bioactivity during GH showed a wide variation, and there was a disrupted correlation with immunoreactive IGF-1 levels, which makes immunoreactive IGF-1 levels an inappropriate indicator for GH dosing in PWSchildren.
Authors: Paulo F Collett-Solberg; Geoffrey Ambler; Philippe F Backeljauw; Martin Bidlingmaier; Beverly M K Biller; Margaret C S Boguszewski; Pik To Cheung; Catherine Seut Yhoke Choong; Laurie E Cohen; Pinchas Cohen; Andrew Dauber; Cheri L Deal; Chunxiu Gong; Yukihiro Hasegawa; Andrew R Hoffman; Paul L Hofman; Reiko Horikawa; Alexander A L Jorge; Anders Juul; Peter Kamenický; Vaman Khadilkar; John J Kopchick; Berit Kriström; Maria de Lurdes A Lopes; Xiaoping Luo; Bradley S Miller; Madhusmita Misra; Irene Netchine; Sally Radovick; Michael B Ranke; Alan D Rogol; Ron G Rosenfeld; Paul Saenger; Jan M Wit; Joachim Woelfle Journal: Horm Res Paediatr Date: 2019-09-12 Impact factor: 2.852
Authors: Daniel B Hawcutt; Jennifer Bellis; Victoria Price; Anne Povall; Paul Newland; Paul Richardson; Matthew Peak; Jo Blair Journal: PLoS One Date: 2017-07-17 Impact factor: 3.240
Authors: Layla Damen; Melitza S M Elizabeth; Stephany H Donze; Sjoerd A A van den Berg; Laura C G de Graaff; Anita C S Hokken-Koelega Journal: J Clin Med Date: 2022-02-26 Impact factor: 4.241