Serum levels of insulin‐like growth factor binding proteins in Ecuadorean children with growth hormone insensitivity

Burren CP, Wanek D, Mohan S, Cohen P, Guevara‐Aguirre J, Rosenfeld RG. Serum levels of insulin‐like growth factor binding proteins in Ecuadorean children with growth hormone insensitivity. Acta Pædiatr 1999; Suppl 428: 185–91. Stockholm. ISSN 0803–5326 Although insulin‐like growth factor binding proteins (IGFBPs) are known to be important modulators of the action of insulin‐like growth factors (IGFs), regulation of their production in vivo is not completely understood. Serum concentrations of IGFBP‐3, ‐4 and ‐5 and acid‐labile subunit (ALS) were therefore examined in 20 children with growth hormone (GH) insensitivity before and after 6 months of therapy with recombinant human IGF‐I (80 or 120 ug/kg twice daily). The IGFBP concentrations in these children were compared with those in 62 GH‐deficient children receiving GH therapy for 3 months. Serum levels of IGFBP‐3, ‐4 and ‐5 and ALS all increased significantly (p < 0.0001) in GH‐deficient children in response to GH therapy, whereas no significant increases occurred in the children with GH insensitivity. These findings indicate that GH is responsible for the regulation of serum levels of IGFBP‐3, ‐4 and ‐5 and ALS, and that IGF‐I does not directly regulate the concentrations of these circulating IGFBPs. □Growth hormone, growth hormone insensitivity, insulin‐like growth factor I, insulin‐like growth factor binding protein