Effects of Insulin-Like Growth Factor I (IGF-I) Administrations on Serum IGF Binding Proteins (IGFBPS) in Patients with Growth Hormone Deficiency

Recently, with an availability of recombinant human insulin-like growth factor I (IGF-I), IGF-I has been tried for various clinical therapeutic applications. IGFs are found in blood complexed to specific binding proteins (IGFBPs), and these IGFBPs might influence the biological effect of administered IGF-I. Therefore, it is interesting to study the responses of serum IGFBPs to IGF-I administrations. We have previously reported that serum IGFBP-I levels increased after single sc injection of IGF-I, and serum IGFBP-2 levels increased and decreased serum IGFBP-3 and acid labile subunit levels after repetitive IGF-I injections in normal subjects1. We report here the responses of IGFBPs to single and repetitive IGF-I sc injections in patients with growth hormone (GH) deficiency.