growth hormone deficiency

(noun)

Growth hormone deficiency (GHD) is a medical condition caused by problems arising in the pituitary gland in which the body does not produce enough growth hormone (GH).

Related Terms

Examples of growth hormone deficiency in the following topics:

  • Hormonal Abnormalities and Height

    • Abnormal production of growth hormone due to tumors on the pituitary or other genetic causes can cause pathological changes in growth.
    • However, if these are not factors, then growth hormone deficiency may be the cause.
    • Growth hormone deficiency (GHD) is a medical condition in which the body produces insufficient growth hormone.
    • Growth hormone, also called somatotropin, is a polypeptide hormone which stimulates growth and cell reproduction.
    • Growth hormone deficiency has no single definite cause.

  • Pituitary Gland Disorders

    • Disorders of pituitary gland can affect hormones which regulate growth and activity of other glands in the body.
    • Growth hormone (GH) excess is rare in children and is referred to as pituitary gigantism , because the excessive growth hormone produces excessive growth of bones and the child can achieve excessive height; from 2.1 to 2.7 m (6'11" to 8'11") in stature by adulthood if left untreated.
    • If elevated growth hormone levels occur before the closure of the epiphyses (i.e. in prepubertal children), then gigantism ensues.
    • Pituitary adenoma affects hormones which regulate growth and the activity of other glands in the body.
    • Measurement of ACTH and growth hormone usually requires dynamic testing, whereas the other hormones (LH/FSH, prolactin, TSH) can typically be tested with basal levels.

  • Development of the Endocrine System

    • The endocrine system regulates growth, metabolism, and body homeostasis using hormones that target organs via the bloodstream.
    • A deficiency of iodine in the diet leads to the enlargement of the thyroid gland, known as a simple goiter.
    • The most popular of these defects is one that results from dietary iodine deficiency.
    • Thyroxine is also necessary for normal growth, likely by promoting the effects of growth hormone on protein synthesis.
    • The absence of thyroxine significantly reduces the ability of growth hormone to stimulate amino acid uptake and RNA synthesis.

  • Aging and the Endocrine System

    • Three hormone axes are affected by aging: growth hormone/insulin-like growth factor I, cortisol/dehydroepiandrosterone, and testoterone/estradiol.
    • The endocrine system consists of glands and organs that produce and release hormones that affect the body in different ways and help control functions including tissue homeostasis, growth and development, reproduction, response to stress, and metabolism.
    • Three of the most important hormone axes in the endocrine system that are affected by aging include growth hormone (GH)/insulin-like growth factor I (IGF-I), cortisol/dehydroepiandrosterone (DHEA), and testosterone/estradiol.
    • Decreases in IGF-I signaling, GH deficiency, and GH resistance cause delayed aging and extended lifespan in animal models, in sharp contrast to the effects of GH/IGF-I in humans.
    • Testosterone is a steroid hormone secreted by the Leydig cells that can act upon many target organs, resulting in development of secondary sexual characteristics and growth spurt at puberty.

  • Formation, Storage, and Release of Thyroid Hormones

    • Thyroid hormones (T4 and T3) are produced by the follicular cells of the thyroid gland and regulated by thyroid-stimulating hormone (TSH).
    • The thyroid hormones thyroxine (T4) and triiodothyronine (T3) are produced from thyroid follicular cells within the thyroid gland, a process regulated by the thyroid-stimulating hormone secreted by the anterior pituitary gland.
    • T4 is believed to be a pro-hormone and a reservoir for the more active and main thyroid hormone T3.
    • If there is a deficiency of dietary iodine, the thyroid will not be able to make thyroid hormone.
    • This enlarged endemic colloid goiter has the effect of increasing the thyroid's ability to trap more iodide, compensating for the iodine deficiency and allowing it to produce adequate amounts of thyroid hormone.

  • Lipid-Derived, Amino Acid-Derived, and Peptide Hormones

    • All hormones in the human body can be divided into lipid-derived, amino acid-derived, and peptide hormones.
    • The primary class of lipid hormones in humans is the steroid hormones.
    • Examples of steroid hormones include estradiol, which is an estrogen, or female sex hormone, and testosterone, which is an androgen, or male sex hormone.
    • This class also includes small proteins, such as growth hormones produced by the pituitary, and large glycoproteins, such as follicle-stimulating hormone produced by the pituitary .
    • The structures of peptide hormones (a) oxytocin, (b) growth hormone, and (c) follicle-stimulating hormone are shown.

  • Congenital Adrenal Hyperplasia

    • Cortisol is an adrenal steroid hormone that is required for normal endocrine function.
    • The resulting excessive or deficient production of these three classes of hormones produce the most important problems for people with CAH.
    • CAH due to deficiencies of enzymes other than 21-hydroxylase present many of the same management challenges as 21-hydroxylase deficiency, but some involve mineralocorticoid excess or sex steroid deficiency.
    • providing replacement mineralocorticoid and extra salt if the person is deficient
    • additional treatments to optimize growth by delaying puberty or delaying bone maturation

  • Hormonal Regulation of Growth

    • Body growth is controlled by growth hormone (GH), produced by the anterior pituitary, and IGF-1, whose production is stimulated by GH.
    • Hormonal regulation is required for the growth and replication of most cells in the body.
    • GH release is stimulated by growth hormone-releasing hormone (GHRH) and is inhibited by growth hormone-inhibiting hormone (GHIH), also called somatostatin.
    • A balanced production of growth hormone is critical for proper development.
    • Oversecretion of growth hormone can lead to gigantism in children, causing excessive growth.

  • Growth Factors

    • Growth factors, cytokines, and hormones are all chemical messengers that mediate intercellular communication.
    • Growth factors are typically cytokines or hormones, but not all cytokines and hormones are growth factors.
    • A cytokine differs from a hormone in that it is not secreted from a gland.
    • As with cytokines, some are involved with growth, such as the growth hormone produced by the anterior pituitary gland, and may be classed as growth factors, but others are not.
    • The majority of growth factors shown above are cytokines such as GM-CSF, however the hormone EPO secreted by the kidney plays a key role in erythrocyte (red blood cell) proliferation.

  • Control of Thyroid Hormone Release

    • TSH release, in turn, stimulates the hypothalamus to secrete thyrotropin-releasing hormone (TRH).
    • This results in increased metabolism, growth, development and the activation of numerous other systems controlled by thyroid hormones.
    • Thyroid hormones also provide negative feedback to the hypothalamus and anterior pituitary gland.
    • Thyroid hormones are produced from the thyroid under the influence of thyroid-stimulating hormone (TSH) from the anterior pituitary gland, which is itself under the control of thyroptropin-releasing hormone (TRH) secreted by the hypothalamus.
    • Thyroid hormones provide negative feedback, inhibiting secretion of TRH and TSH when blood levels are high.