Acromegaly is a disorder resulting from excess growth hormone (GH) after the growth plate is closed. The initial symptoms are usually the enlargement of the hands and feet. There may also be an enlarged forehead, jaw, and nose. Other symptoms may include joint pain, thicker skin, deepening of voice, headache, and vision problems. Complications of this disease may include type 2 diabetes, sleep apnea, and high blood pressure.
Acromegaly is usually caused by a pituitary gland that produces too much growth hormone. In over 95% of cases, excess production is caused by a benign tumor, known as pituitary adenoma. This condition is not inherited from one's parents. Rarely acromegaly is due to tumors in other parts of the body. Diagnosis is by measuring the growth hormone after a person takes glucose or by measuring growth factors such as insulin in the blood. After diagnosis, pituitary medical imaging is performed to look for adenomas. If excess growth hormone is produced during childhood, the result is gigantism.
Treatment options include surgery to remove tumors, medications, and radiation therapy. Surgery is usually the preferred treatment and most effective when the tumor is smaller. In those with ineffective surgery, drugs from somatostatin analogs or GH receptor antagonist types may be used. The effects of radiation therapy are more gradual than surgery or treatment. Without treatment, those affected live an average of 10 years less; with treatment, however, life expectancy is usually normal.
Acromegaly affects about 6 per 100,000 people. It is most commonly diagnosed in middle age. Men and women are affected with the same frequency. The first medical description of the disorder occurred in 1772 by Nicolas Saucerotte. This term is derived from the Greek ????? akron which means "extremity" and ???? mega which means "big".
Video Acromegaly
Signs and symptoms
The features resulting from high levels of GH or tumors include:
- Soft tissue swelling is seen to cause enlargement of the hands, feet, nose, lips and ears, and skin thickening in general
- Soft tissue swelling of the internal organs, especially the heart accompanied by weak muscles, and kidneys, as well as the vocal cords that produce thick sound, deep voice, and speech deceleration.
- General skull expansion in fontanel
- Spoken eyebrows, often with ocular distension (frontal bossing)
- Pronounced lower jaw (prognathism) with the presence of makroglossia (tongue enlargement) and tooth spacing
- Hypertrichosis, hyperpigmentation and hyperhidrosis can occur in these patients.
- Acrochordon (skin tag)
- Carpal tunnel syndrome
Complications
- Severe headache
- Arthritis and carpal tunnel syndrome
- Enlarged heart
- Liver fibrosis and bile duct hyperplasia.
- Hypertension
- Diabetes mellitus (excess GH leads to insulin resistance)
- Heart failure
- Kidney failure
- Colorectal cancer
- Optical chiasma compression causes loss of vision in the external visual field (usually a bitemporal hemianopia.)
- Increased palmar sweats and sebum production above the face (seborrhea) is a clinical indicator of an active GH-producing pituitary tumor. These symptoms can also be used to monitor tumor activity after surgery, although biochemical monitoring is confirmation.
Maps Acromegaly
Cause
Pituitary adenoma
Approximately 98% of cases of acromegaly are caused by excess production of growth hormone by benign pituitary gland tumors called adenomas. These tumors produce excessive growth hormones and suppress the surrounding brain tissue as they grow larger. In some cases, they can suppress the optic nerve. Expansion of the tumor can cause headaches and visual impairment. In addition, compression of normal pituitary tissue may alter the production of other hormones, leading to menstrual changes and breast implants in women and impotence in men due to reduced production of testosterone.
Significant variation in GH production rates and tumor aggressiveness occurs. Some adenomas grow slowly and symptoms of GH excess are often unnoticed for years. Another adenoma grows rapidly and invades the surrounding area of ​​the brain or sinuses, located near the pituitary. In general, younger patients tend to have more aggressive tumors.
Most pituitary tumors arise spontaneously and are not genetically inherited. Many pituitary tumors arise from genetic changes in a single pituitary cell leading to increased cell division and tumor formation. This genetic change, or mutation, is absent at birth, but is acquired during life. Mutations occur in genes that regulate the transmission of chemical signals in pituitary cells; permanently switches to signals that tell the cell to divide and excrete growth hormones. The occurrences within cells that cause irregular pituitary cell growth and current GH oversecretion are the subject of intensive research.
Pituitary adenomas and diffuse somatomammotroph hyperplasia may result from mutations of somatic activation GNAS , which may be obtained or associated with McCune-Albright syndrome.
Other tumors
In some patients, acromegaly is not caused by pituitary tumors, but by pancreatic tumors, lung, and adrenal glands. These tumors also cause excess GH, either because they produce their own GH or, more often, because they produce GHRH (hormone releasing hormone growth), a hormone that stimulates the pituitary to make GH. In these patients, excess GHRH may be measured in the blood and establish that the cause of acromegaly is not due to pituitary defects. When this non-hypothermal tumor is surgically removed, the GH level decreases and the acromegaly symptoms improve.
In patients with GHRH-producing tumors, non-pituitary, the pituitary may still be enlarged and may be misinterpreted as a tumor. Therefore, it is important that doctors carefully analyze all "pituitary tumors" removed from patients with acromegaly so as not to ignore the possibility that tumors elsewhere in the body cause such disorders.
Diagnosis
If suspected, medical imaging and medical laboratory examinations are commonly used together to confirm or exclude the presence of this condition.
IGF1 provides the most sensitive laboratory tests for the diagnosis of acromegaly, and the GH suppression test after oral glucose load, which is a very specific laboratory test, will confirm the diagnosis after positive screening tests for IGF1. A single GH value is useless given its pulse (blood levels vary greatly even in healthy individuals).
GH levels taken 2 hours after a glucose tolerance test of 75 or 100 grams are helpful in diagnosis: GH levels are pressed below 1 Âμg/l in normal people, and a higher level of this cutoff is a confirmation of acromegaly.
Other pituitary hormones should be assessed to overcome the effects of tumor secretion, as well as the effect of tumor mass on the normal pituitary gland. They include thyroid stimulating hormone (TSH), gonadotropic hormone (FSH, LH), adrenocorticotropic hormone, and prolactin.
A brain MRI that focuses on sella turcica after gadolinium administration allows for clear representation of the pituitary and hypothalamus and tumor sites. A number of other excess growth syndromes can cause similar problems.
Pseudoacromegaly
Pseudoacromegaly is a condition with the usual acromegaloid features, but without increased growth hormone and IGF-1. This is often associated with insulin resistance. Cases have been reported due to minoxidil at very high doses. It can also be caused by selective postreceptor defects against insulin signaling, which causes metabolic disorders, but mitogenic preservation, signaling.
Treatment
There is no known cure for acromegaly. The goal of treatment is to reduce the production of GH to normal levels, to reduce the pressure of pituitary tumors that grow in the area of ​​the surrounding brain, to maintain normal pituitary function, and to reverse or improve acromegaly symptoms. Currently, treatment options include surgical removal of tumors, drug therapy, and pituitary radiation therapy.
Drugs
Analog Somatostatin
The main current medical treatment of acromegaly is using somatostatin-octreotid analog (Sandostatin) or lanreotide (Somatuline) analogues. This somatostatin analogue is a synthetic form of the brain hormone, somatostatin, which halts the production of GH. These long-acting forms of these drugs should be injected every 2 to 4 weeks for effective treatment. Most patients with acromegaly respond to this drug. In many patients, GH levels fall within an hour and headaches improve within minutes after injection. Octreotide and lanreotide are effective for long-term treatment. Octreotide and lanreotide have also been successfully used to treat patients with acromegaly caused by non-pituitary tumors.
Analog somatostatin is sometimes also used to shrink large tumors before surgery.
Because octreotides inhibit gastrointestinal and pancreatic function, long-term use causes digestive problems such as loose stools, nausea, and gas in one-third of patients. In addition, about 25 percent of patients experience gallstones, which are usually asymptomatic. In some cases, ocreotid treatment can lead to diabetes due to the fact that somatostatin and its analogues can inhibit insulin release.
dopamine agonists
For those unresponsive to somatostatin analogues, or for whom they are contraindicated, it is possible to treat using either dopamine, bromocriptine or cabergoline agonists. As a tablet and not a shot, the price is much cheaper. These medications can also be used as an adjunct to somatostatin analog therapy. They are most effective in those whose pituitary tumors produce prolactin. Side effects of this dopamine agonist include gastrointestinal disorders, nausea, vomiting, dizziness when standing, and nasal congestion. These side effects can be reduced or eliminated if the drug starts with a very low dose at bedtime, taken with food, and gradually increases to a full therapeutic dose. Bromocriptine lowers GH and IGF-1 levels and reduces tumor size in fewer than half of patients with acromegaly. Some patients report improvements in their symptoms even though their GH and IGF-1 levels are still rising.
Growth hormone receptor antagonist
The latest development in medical treatment of acromegaly is the use of growth hormone receptor antagonists. The only member available from this family is pegvisomant (Somavert). By blocking the action of endogenous growth hormone molecules, these compounds are able to control the activity of acromegaly disease in almost all patients. Pegvisomant should be administered subcutaneously with daily injections. The combination of a long-acting somatostatin analogue and a weekly injection of pegvisomant appears to be as effective as daily injections of pegvisomant.
Surgery
Surgery is a quick and effective treatment, in which there are two alternative methods. The first method, a procedure known as endonasal transphenoidal surgery, involves the surgeon reaching the pituitary through an incision in the nasal cavity wall. The walls are achieved by passing through the nostrils with a micro instrument. The second method is a transphenoidal operation where the incision is made into chewing gum under the upper lip. A further incision is made to cut through the septum to reach the nasal cavity, where the pituitary is located. Endonasal transphenoidal surgery is a less invasive procedure with a shorter recovery time than the old method of transphenoidal surgery, and the possibility to remove all larger tumors by reducing side effects. As a result, endonasal transphenoidal surgery is often used as a first choice, with transphenoidal and other treatments, such as drug therapy or stereotactic radiosurgery, used to reduce remaining residual effects of the remaining tumors.
These procedures usually reduce the pressure on the surrounding brain region and cause a decrease in GH levels. Surgery is most successful in patients with blood GH levels below 40 ng/ml before surgery and with pituitary tumors not greater than 10 mm. Success depends on the skill and experience of the surgeon. The success rate also depends on the level of GH defined as the drug. The best measure of successful surgery is normalization of GH and IGF-1 levels. Ideally, GH should be less than 2 ng/ml after oral glucose load. A GH-level review of 1,360 patients worldwide immediately after the surgery revealed that 60% had a random level of GH below 5 ng/ml. Complications of surgery may include cerebrospinal fluid leak, meningitis, or destruction of the surrounding pituitary tissue, requiring lifelong pituitary hormone replacement.
Even when the surgery is successful and hormone levels return to normal, the patient should be carefully monitored for years for possible recurrence. More generally, hormone levels may improve, but do not return fully to normal. These patients may require additional treatment, usually with medication.
Radiation therapy
Radiation therapy has been used both as a primary treatment and combined with surgery or medication. Usually reserved for patients who have tumors left after surgery. These patients often also receive medications to lower GH levels. Radiation therapy is given in divided doses for four to six weeks. This treatment lowers GH levels by about 50 percent for 2 to 5 years. Patients monitored for more than 5 years showed a significant further increase. Radiation therapy causes the loss of production of other pituitary hormones gradually over time. Loss of vision and brain injury, which has been reported, is a very rare complication of radiation treatment.
Options
There is no single effective treatment for all patients. Treatment should be individualized depending on patient characteristics, such as age and tumor size. If the tumor has not invaded the surrounding brain tissue, removal of pituitary adenomas by experienced neurosurgeons is usually the first choice. After surgery, a patient should be monitored for a long time to raise the GH level. If surgery does not normalize hormone levels or relapse, doctors will usually start additional drug therapy. The current first choice is generally okreotida or lanreotide. Bromocriptine or cabergoline is much cheaper and easier to manage. With both types of treatment, long-term therapy is necessary because their withdrawal may lead to an increase in GH levels and tumor expansion. Radiation therapy is generally used for patients whose tumors are not completely eliminated by surgery; for patients who are not good candidates for surgery due to other health problems; and for patients who do not respond adequately to surgery and treatment.
Prognosis
After successful treatment, symptoms and complications generally increase substantially or disappear, including headaches, visual impairment, excessive sweating, and diabetes. Swelling of the soft tissue generally decreases and the facial features associated with acromegaly are gradually returning to normal, although this may take time. Life expectancy after the success of early acromegaly treatment equals normal population.
Famous cases
The famous people with acromegaly include:
- Richard Kiel, actor, "Jaws" from two James Bond movies and Mr. Larson at Happy Gilmore . It grows up to 7 ft. 1.5 in (2.17 m), but is a little under 7 feet (2.13 m) in its final years due to age and injury.
- PÃÆ'o Pico, the last Mexican governor in California (1801-1894), embodied acromegaly without gigantism between at least 1847 and 1858. Sometime after 1858, signs of growth hormone-producing tumors disappeared along with all secondary effects the tumor had caused. She looked normal in her 90s. His remarkable recovery is probably an example of spontaneous selective pituitary apoplexy tumors.
- Adam Rainer, born in 1899, an Austrian man, is by far the only one recorded in history is a dwarf and a giant. The rapid change from dwarf to giant is believed to be caused by acromegaly. He died on March 4, 1950.
- Tony Robbins, motivational speaker
- AndrÃÆ'Â © the Giant (born AndrÃÆ' Â © Roussimoff), French professional wrestler and actor is 2.13 m (7 feet) after back surgery; wrestling statistics originally recorded it at 2.23 m (7 ft 4 in). He died at the age of 46 and weighed 240 kilograms (530 pounds). (He chose not to be treated and died of cardiac complications from acromegaly.)
- The Big Show (born Paul Wight), a professional American wrestler and actor, currently working for WWE, has discarded his pituitary tumor in 1991.
- The Great Khali (born Dalip Singh Rana), an Indian professional wrestler, is renowned for his tenure with WWE. She has her pituitary tumor removed in 2012, aged 39 years.
- AntÃÆ'Â'nio Silva, a mixed Brazilian martial artist, competes in the UFC heavyweight division.
- Maurice Tillet (1903-1954), a Russian-born Russian professional wrestler, better known as the ring, the French Angel.
- Ted Cassidy, American actor, best known for playing Lurch in the original Addams Family family TV series.
- Carel Struycken, Dutch actor, 2.13m (7ft), famous for playing Lurch in The Addams Family the trilogy movie, The Giant in
, and the Silent Servant Lwaxana Troi, Mr. Homn on Star Trek: The Next Generation . - Irwin Keyes, an American actor. Best known for describing Hugo Mojoloweski, George's occasional bodyguard at The Jeffersons
- Paul Benedict, American actor. Best known for describing Harry Bentley, The Jeffersons the English next door
- Rondo Hatton, American actor. Hollywood favorites in B-movie horror movies of the 1930s and 1940s. Hatton's damage, due to acromegaly, evolved over time, beginning during his service in World War I.
- Morteza Mehrzad, Iranian Paralympics and medalist. The volleyball team sat Iran. Top scorer in the 2016 gold medal match.
See also
- The hypothalamic-pituitary-somatic axis
References
External links
- Acromegaly in Curlie (based on DMOZ)
- The American Association of 2011 on Klini's Endocrinological Guidelines,
- Endocrine and Metabolic Disease Information Services
Source of the article : Wikipedia
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