Physiology of an Eating Disorder
Jonna Fries, Veronica Sullivan in Eating Disorders in Special Populations, 2017
More than 50% of adolescents with AN have evidence of osteopenia and 25% have osteoporosis (Zipfel et al. 2001). Ninety percent have evidence of reduced bone density. Malnutrition and estrogen deficiency can lead to decreased bone density. The bone metabolism is abnormal in anorexic patients due to the effects of malnutrition on osteoblastic activity as well as excessive exercise. The laboratory results will show low estrogen, low growth hormone, androgen, and T3 levels. The markers of bone formation are osteocalcin and bone alkaline phosphatase, which will be low. IGF-1 recombinant human insulin-like growth factor 1 is a hormone similar in molecular structure to insulin. It plays an important role in childhood growth and continues to have anabolic effects in adults. Giving external estrogen is not beneficial as it inhibits IGF-1. Recombinant IGF-1 promotes bone formation and reduces bone resorption (Vaisman et al. 1991). The best treatment is weight gain.
Endocrine system
Brian J Pollard, Gareth Kitchen in Handbook of Clinical Anaesthesia, 2017
GH (somatotropin) is secreted by the somatotrophic cells of the anterior pituitary. It stimulates the production of insulin-like growth factor-1 (IGF-1) in the liver. Regulation of GH secretion is complex and under both stimulatory and inhibitory control. Secretion is stimulated by GHRH (growth hormone releasing hormone) and ghrelin as well as androgens during puberty. Dopaminergic mechanisms contribute to the regulation of GHRH secretion; L-DOPA increases and bromocriptine suppresses secretion. GH secretion is inhibited by the hypothalamic hormone somatostatin and is also under negative feedback control of circulating GH and IGF-1. Hyperglycaemia and glucocorticoids also inhibit GH secretion. To illustrate the complex interactions, hypoglycaemia, the standard clinical test of somatotroph function, does not directly stimulate GH release but acts indirectly by inhibiting somatostatin and thus removing its inhibitory effect on GH secretion.
Malignant Neoplasms of the Colon
Philip H. Gordon, Santhat Nivatvongs, Lee E. Smith, Scott Thorn Barrows, Carla Gunn, Gregory Blew, David Ehlert, Craig Kiefer, Kim Martens in Neoplasms of the Colon, Rectum, and Anus, 2007
In a meta-analysis of 18 epidemiologic studies of postmenopausal hormone therapy and colorectal carcinoma Grodstein et al. (204) found a 20% reduction in risk of colon carcinoma and a 19% decrease in the risk of rectal carcinoma for postmenopausal women who had ever taken hormone therapy compared with women who never used hormones. Much of the apparent reduction in colorectal carcinoma was limited to current hormone users (relative risk = 0.66). From a case-control study among women, ever use of hormone replacement therapy was more strongly associated with reduced risk of advanced adenomas relative to polyp-free controls (OR = 0.4) than with reduced risk of nonadvanced adenomas (OR = 0.7) (191). Baris et al. (205) studied the patterns of carcinoma risk in Sweden and Denmark in 177 patients with acromegaly. Increased risks were found for colon (standardized incidence ratio = 2.6) and rectum (standardized incidence ratio = 2.5). Among other risks, the increased risk for several carcinoma sites among acromegaly patients may be due to the elevated proliferative and antiapoptotic activity associated with increased circulating levels of insulin-like growth factor-1.
Plasma insulin-like growth factor binding protein 1 in pulmonary arterial hypertension
Published in Scandinavian Cardiovascular Journal, 2021
Habib Bouzina, Roger Hesselstrand, Göran Rådegran
Insulin-like growth factor 1 (IGF-1) is a hormone with similar structure as insulin, which serves as an anabolic hormone in adults. When binding to the receptor tyrosine kinase IGF-1 receptor, IGF-1 initiates molecular cascades that play a pivotal role in cellular proliferation and survival [13]. An altered IGF-1 and IGF-1 receptor system is indeed associated with several malignancies [13]. IGF-1 and IGF-1 receptor signalling has also been implied to influence pulmonary hypertension (PH) [14–16]. In neonatal hypoxic PH models, IGF-1 depletion may reduce right ventricular (RV) hypertrophy and vascular remodelling in small pulmonary arteries [15]. IGF binding protein (IGFBP)-1, which acts as a carrier protein that binds to and modulates IGF-1 [13], has additionally been shown to predict survival in PAH patients [17].
Resistance training effect on serum insulin-like growth factor 1 in the serum: a meta-analysis
Published in The Aging Male, 2020
Guanlun Ye, Zhifang Xiao, Zhuozhang Luo, Xiaomin Huang, Mohamed E. A. Abdelrahim, Wenlong Huang
Aging is a progressive and non-reversible process characterized by a slow and steady worsening of the physiology of the body. The progression is also accompanying deterioration in the level of anabolic hormones, notably insulin-like growth factor 1, which is a vital mediator for growth hormone associated signaling pathways [1]. The main roles for insulin-like growth factor 1 include the regulation of cell metabolism, growth, proliferation, and apoptosis in multiple organ systems; hence, the net effect of insulin-like growth factor 1 includes supporting newborn and children growth and applying anabolic properties in adults [2]. Preserving optimal levels of insulin-like growth factor 1 in serum is very critical for wellbeing. Hyper-secretion of insulin-like growth factor 1 is associated with cancers [3] and acromegaly [4], while decreased serum insulin-like growth factor 1 is linked to augmented risk for type 2 diabetes [5].
Does cord blood leptin level mediate the association between neonatal body size and postnatal growth? Results from the EDEN mother–child cohort study
Published in Annals of Human Biology, 2020
Marion Taine, Olfa Khalfallah, Anne Forhan, Nicolas Glaichenhaus, Marie-Aline Charles, Barbara Heude
These physiological mechanisms deserve to be better understood (Gat-Yablonski and Phillip 2015). If several hormones seem to be involved, the importance of their role to help the infant to reach his/her growth potential has not been assessed yet (Gat-Yablonski and Phillip 2015). Several studies have shown high birth weight associated with high concentrations of certain cord blood hormones such as leptin, insulin-like growth factor 1, and c-peptide (Leger et al. 1996; Ong et al. 1999; Verkauskiene et al. 2007; Mantzoros et al. 2009; Karakosta et al. 2011). Conversely, low birth weight was associated with low concentrations of these three hormones (Leger et al. 1996; Ong et al. 1999; Verkauskiene et al. 2007; Mantzoros et al. 2009; Karakosta et al. 2011). Insulin-like growth factor 1 is one of the main growth factors (Laron 2001); its low levels in newborns with intrauterine growth retardation cannot explain a growth acceleration over the first months of life (Leger et al. 1996). However, low cord blood leptin level could be responsible for such early growth acceleration in newborns with intrauterine growth retardation and early deceleration in newborns with macrosomia.
Related Knowledge Centers
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