Insulin-like growth factor-I (IGF-I) and clinical nutrition

Abstract

IGF-I (insulin-like growth factor-I) is a peptide hormone, produced predominantly by the liver in response to pituitary GH (growth hormone), which is involved in a wide variety of physiological processes. It acts in an endocrine, paracrine and autocrine manner to promote growth. The production of IGF-I signals the availability of nutrients needed for its anabolic actions. Recently, there has been growing interest in its role in health and disease. IGF-I has long been known to be regulated by nutrition and dysregulated in states of under- and over-nutrition, its serum concentrations falling in malnutrition and responding promptly to refeeding. This has led to interest in its utility as a nutritional biomarker. A considerable evidence base supports utility for measurement of IGF-I in nutritional contexts. Its concentration may be valuable in providing information on nutritional status, prognosis and in monitoring nutritional support. However, it is insufficiently specific for use as a screening test for under nutrition as its serum concentration is influenced by many factors other than nutritional status, notably the APR (acute-phase response) and endocrine conditions. Concentrations should be interpreted along with clinical findings and the results of other investigations such as CRP (C-reactive protein). More recently, there has been interest in free IGF-I which holds promise as a nutritional marker. The present review covers nutritional regulation of IGF-I and its dysregulation in disease, then goes on to review recent studies supporting its utility as a nutritional marker in clinical contexts. Although not currently recommended by clinical guidelines, it is likely that, in time, measurement of IGF-I will become a routine part of nutritional assessment in a number of these contexts.

Proprotein convertase furin/PCSK3 and atherosclerosis: New insights and potential therapeutic targets

“…Insulin-like growth factor-1 (IGF-1), which is mainly produced by the liver, participates in diverse physiological processes [93]. The in vitro and in vivo studies showed that the interaction of IGF-1 and IGF-1R is essential for cell growth and survival of various transformed cells [94].…”

Potassium diformate influences gene expression of GH/IGF-I axis and glucose homeostasis in weaning piglets

“…Previous observations also found that addition of KDF to the diet improved growth performance in post-weaning piglets (Paulicks et al, 2000;Htoo and Molares, 2012), and increased ADG and ADFI in growing-finishing pigs (Overland et al, 2000;Mroz et al, 2002). Furthermore, the expression of IGF-I from peripheral tissue is also GH dependent, it plays an important role in body growth via autocrine/paracrine manner (Livingstone, 2013). Iresjö et al (2013) observed that re-synthesis of muscle proteins following starvation is not critically dependent on endocrine liver-derived IGF-I.…”

Hormonal dysfunction is frequent in cancer survivors treated with radiotherapy to the head and neck region

“…Dysfunction in the GH axis is difficult to estimate in basal blood samples since IGF-1 level is not regulated by GH alone, but also by other factors such as insulin level and nutritional status [25]. Provocative testing of the GH axis, such as testing of GH response to insulin-induced hypoglycemia or arginine and GH releasing hormone in combination, is critical to diagnosing GH deficiency.…”