Do you know about child growth deficiency disorder?
Overview of human growth hormone (hGH)
What is hGH?
hGH (somatotropin) is produced by somatotroph cells in the anterior pituitary gland of the brain
hGH is the most abundant pituitary hormone. It is encoded by the GH1 gene, which is part of a cluster of five genes located on 17q22.
Effects on growth
The main role of hGH in body growth is to stimulate the liver and other tissues to secrete IGF-1. IGF-1is important in bone growth for the differentiation and hypertrophy of chondrocytes. Chondrocytes are unique cells in articular cartilage tissue and are essential for cartilage formation and functionality. hGH also acts directly on the germinal zone of the growth plate. hGH affects bone mineralization by increasing bone turnover, bone mineral density and bone mineral content without modifying phosphate and calcium metabolism. IGF-1 also appears to play a key role in muscle growth. IGF-1 stimulates both the differentiation and proliferation of myoblasts. It also stimulates amino acid uptake and protein synthesis in muscle and other tissues.
Metabolic effects
hGH has important effects on protein, lipid and carbohydrate metabolism.
Regulation of hGH secretion
The production of hGH is modulated by many factors, including stress, exercise, nutrition, sleep and hGH itself. However, the primary controllers of hGH are two hypothalamic hormones and one hormone from the stomach.
Growth hormone-releasing hormone (GHRH) stimulates the synthesis and secretion of hGH from the pituitary gland.
Somatostatin (SST) is a peptide produced by several tissues in the hypothalamus and elsewhere in the body. It inhibits the release of hGH.
Ghrelin is a peptide hormone secreted from the stomach. It binds to receptors on somatotroph cells in the pituitary gland and stimulates secretion of hGH.
hGH secretion is part of a negative feedback system. High levels of IGF-1 lead to suppression of hGH by directly suppressing the somatotroph cells and also stimulating the release of somatostatin from the hypothalamus. hGH also inhibits GHRH secretion.
What are the growth hormone deficiency disorders?
There are a group of disorder related to growth hormone deficiency disorder. These are:
• Paediatric growth hormone deficiency (pGHD)
• Adult growth hormone deficiency (aGHD)
• Turner syndrome (TS)
• Chronic renal insufficiency (CRI)
• Small for gestational age (SGA)
• Prader-Willi syndrome (PWS)
• Idiopathic short stature (ISS)
