Growth Hormone-Binding Protein Measurements in Normal Children and Children with Short Statute Using Ligand-Mediated Immunofunctional Assay

Abstract

To investigate the role of growth hormone (GH) and its downstream axis in normal growth and growth disorders, we measured serum GH-binding protein (GHBP) levels in normal children and children with short stature by ligand-mediated immunofunctional assay (LIFA). Samples were obtained from 512 healthy children with normal stature, 146 5-day-old healthy neonates, and 153 short children with normal GH secretion (normal short children). Serum GHBP showed significant correlation with percent overweight (r=0.71, P<0.01) in normal children. Diurnal variations in serum GHBP were scarcely observed. Serum GHBP levels were low in neonates, rose acutely within 6 months, and gradually increased toward pubertal age in normal children (r=0.2, P<0.01, assessed among subjects over 1 year old). Neither significant sex differences nor rapid peaked changes during puberty were observed. In normal short children, GHBP levels were lower than in normal controls.These data suggest resistance to GH or low efficacy of GH utilization could be one of the etiologies of growth disorder in normal short children.