title: Insulin-like growth factors as diagnostic tools in growth hormone deficiency during childhood and adolescence: the KIGS experience.
abstract: Growth hormone (GH) deficiency in children covers a spectrum of disorders involving an impairment in GH secretion and a clinical syndrome characterized by permanent stunting of growth. Ascertaining impairments in GH secretion directly is complex, especially if GH deficiency (GHD) is isolated and not caused by congenital or acquired pituitary defects or genetic abnormalities. It has been established that the concentrations of GH-dependent peptides, such as insulin-like growth factor I (IGF-I) and IGF-binding protein 3 (IGFBP-3), are low in patients with GHD. Their levels are, however, also influenced by a multitude of factors, such as age, gender, height, liver function, nutritional status and other hormones. In addition, the type of complex formed, e.g. either binary or ternary, may influence the measurements of IGFs and their binding proteins. Therefore, levels of IGF-I and IGFBP-3 are generally lower in short children compared with age-matched norms. The reported diagnostic value of sub-normal basal levels of IGF-I and IGFBP-3 is, in terms of sensitivity and specificity, approximately 70%. Thus, definite proof of GHD can only be achieved by means of GH measurements. As the diagnosis of GHD is somewhat unlikely if IGF testing shows normal values, it is clearly advantageous to schedule these tests as part of the initial diagnostic work-up in short children, as their implementation is not only practical but also inexpensive. The Pfizer International Growth Database (KIGS) analysis of IGF-I (n = 2,750) and IGFBP-3 (n = 1,300) levels in children with idiopathic GHD shows that these two parameters are now firmly embedded in diagnostic strategies around the world.
authors.affiliation: Paediatric Endocrinology Section, University Children's Hospital, Tubingen, Germany. michael.ranke@med.uni-tuebingen.de
authors.forename: Michael B
authors.initials: MB
authors.lastname: Ranke
authors.forename: Roland
authors.initials: R
authors.lastname: Schweizer
authors.forename: Anders
authors.initials: A
authors.lastname: Lindberg
authors.forename: David A
authors.initials: DA
authors.lastname: Price
authors.forename: Edward O
authors.initials: EO
authors.lastname: Reiter
authors.forename: Kerstin
authors.initials: K
authors.lastname: Albertsson-Wikland
authors.forename: Feyza
authors.initials: F
authors.lastname: Darendeliler
authors.forename: Feyza
authors.initials: F
authors.lastname: Darendelliler
mesh_terms: D000293:Adolescent; D001827:Body Height; D002648:Child; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D019382:Human Growth Hormone / Q000172:deficiency*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000032:analysis; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D011627:Puberty; D012680:Sensitivity and Specificity; D013002:Somatomedins / Q000032:analysis*
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D013002:Somatomedins; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I