title: The Insulin-Like Growth Factor System in Obesity, Insulin Resistance and Type 2 Diabetes Mellitus.
abstract: The insulin-like growth factor (IGF) system, acting in concert with other hormone axes, is important in normal metabolism. In obesity, the hyperinsulinaemia that accompanies peripheral insulin resistance leads to reduced growth hormone (GH) secretion, while total IGF-I levels are relatively unchanged due to increased hepatic GH sensitivity. IGF-binding protein (IGFBP)-1 levels are suppressed in relation to the increase in insulin levels in obesity and low levels predict the development of type 2 diabetes several years later. Visceral adiposity and hepatic steatosis, along with a chronic inflammation, contribute to the IGF system phenotype in individuals with metabolic syndrome and type 2 diabetes mellitus, including changes in the normal inverse relationship between IGFBP-1 and insulin, with IGFBP-1 concentrations that are inappropriately normal or elevated. The IGF system is implicated in the vascular and other complications of these disorders and is therefore a potential therapeutic target.
authors.affiliation: School of Health Nursing & Midwifery, the University of the West of Scotland, Paisley PA1 2BE, UK. Moira.Lewitt@uws.ac.uk.
authors.forename: Moira S
authors.initials: MS
authors.lastname: Lewitt
authors.affiliation: School of Health Nursing & Midwifery, the University of the West of Scotland, Paisley PA1 2BE, UK. Mairi.Dent@uws.ac.uk.
authors.forename: Mairi S
authors.initials: MS
authors.lastname: Dent
authors.affiliation: Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm SE171 76, Sweden. Kerstin.Hall@ki.se.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hall
keywords: GH; IGFBP; insulin-like growth factor; obesity; type 2 diabetes