Growth and its disorders [editorial]

The growth hormone and insulin like growth factors (GH-IGF) play a vital role in the regulation of growth. The GH-IGF axis includes the hypothalamic-pituitary axis (responsible for production of GH) GH receptors (responsible for IGF production) IGF binding proteins (IGFBP responsible for transport of IGF) and IGF receptors (responsible for IGF action). Insulin like growth factors were initially considered to be mediators of GH action but are now considered to be independent endocrine factors which influence a number of biological processes. Recent advances have led to tremendous increase in the clinical utility of the GH-IGF axis. IGF-based investigations (IGF1 and IGFBP 3) are now replacing GH-based investigations for evaluation and monitoring of disorders of the GH-IGF axis including GH deficiency and insensitivity. IGF therapy has been successfully utilized in growth hormone insensitivity syndrome and GH deficiency type 1B. The possibility of IGF axis as a therapeutic option is being explored in other disorders. Anurag Bajpai and P S N Menon discuss the details of GH-IGF axis in this symposium. (excerpt)