Acromegaly overview: Difference between revisions
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==Causes== | ==Causes== | ||
Acromegaly is a hormonal disorder that results from too much growth hormone in the body. Growth hormone is made by the pituitary gland in the brain, usually by a benign pituitary adenoma. | |||
Secretion of growth hormone by the pituitary gland into the bloodstream stimulates the liver to produce another hormone called insulin-like growth factor I (IGF-I). IGF-I is what actually causes tissue growth in the body. High levels of IGF-I, in turn, signal the pituitary to reduce growth hormone production. | |||
The hypothalamus makes another hormone called somatostatin, which inhibits growth hormone production and release. Normally, GHRH, somatostatin, growth hormone, and IGF-I levels in the body are tightly regulated by each other and by sleep, exercise, stress, food intake, and blood sugar levels. If the pituitary continues to make growth hormone independent of the normal regulatory mechanisms, the level of IGF-I continues to rise, leading to bone overgrowth and organ enlargement. High levels of IGF-I also cause changes in glucose (sugar) and lipid (fat) metabolism and can lead to diabetes, high blood pressure, and heart disease. | |||
==Differentiating {{PAGENAME}} from Other Diseases== | ==Differentiating {{PAGENAME}} from Other Diseases== | ||
Revision as of 08:36, 27 September 2016
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Acromegaly (from Greek akros "extreme" or "extremities" and megalos "large" - extremities enlargement) is a hormonal disorder that results from too much growth hormone in the body. The pituitary gland, a small gland in the brain, makes growth hormone. In acromegaly, the pituitary produces excessive amounts of growth hormone, usually from a benign, or noncancerous, tumor on the pituitary gland. These benign tumors are called pituitary adenomas.
Acromegaly most commonly affects middle-aged adults and can result in serious illness and premature death. Because of its insidious onset and slow progression, the disease is hard to diagnose in the early stages and is frequently missed for many years. Common symptoms include slow enlargement of jaw, hands, feet, and coarsening of facial features. The most serious health consequences of acromegaly are type 2 diabetes, high blood pressure, increased risk of cardiovascular disease, and arthritis. Patients with acromegaly are also at increased risk for colon polyps, which may develop into colon cancer if not removed.
When growth hormone-producing adenomas occur in childhood, the disease that results is called gigantism rather than acromegaly. A child’s height is determined by the length of the so-called long bones in the legs. In response to growth hormone, these bones grow in length at the growth plates—areas near either end of the bone. Prior to puberty, excessive growth hormone exposure causes increased height. Growth plates fuse after puberty, so the excessive growth hormone production in adults does not affect height.
Historical Perspective
Classification
Pathophysiology
Causes
Acromegaly is a hormonal disorder that results from too much growth hormone in the body. Growth hormone is made by the pituitary gland in the brain, usually by a benign pituitary adenoma.
Secretion of growth hormone by the pituitary gland into the bloodstream stimulates the liver to produce another hormone called insulin-like growth factor I (IGF-I). IGF-I is what actually causes tissue growth in the body. High levels of IGF-I, in turn, signal the pituitary to reduce growth hormone production.
The hypothalamus makes another hormone called somatostatin, which inhibits growth hormone production and release. Normally, GHRH, somatostatin, growth hormone, and IGF-I levels in the body are tightly regulated by each other and by sleep, exercise, stress, food intake, and blood sugar levels. If the pituitary continues to make growth hormone independent of the normal regulatory mechanisms, the level of IGF-I continues to rise, leading to bone overgrowth and organ enlargement. High levels of IGF-I also cause changes in glucose (sugar) and lipid (fat) metabolism and can lead to diabetes, high blood pressure, and heart disease.