Acromegaly is a serious condition that occurs when the body produces too much growth hormone (GH), the hormone that controls growth. When your body has an excess in GH, it leads to irregular growth of bones, cartilage, muscles, organs, and other tissues. This can cause serious disease and even premature death.
Hormones are natural chemicals made by various organs that get distributed throughout your body. Hormones control many different functions besides growth and development; they also control metabolism, reproduction, and influence your emotions. They affect nearly every system of the body.
Acromegaly is caused by an overproduction of the hormones that control growth.
These hormones include growth hormone, growth hormone-releasing hormone (GHRH), and insulin-like growth factor 1 (IGF-1). In most cases, a benign tumor is applying pressure to your pituitary gland, causing it to produce and distribute these hormones unnecessarily.
In rare cases, a tumor elsewhere in your body, such as the lungs, adrenal glands, or pancreas, can lead to an overproduction of growth hormone, resulting in symptoms of Acromegaly. Non-pituitary tumors found in other areas of the body like the abdomen and chest can also cause Acromegaly in extremely rare cases. The pituitary gland responds to a stimulus to produce GH. For example, some hypothalamic tumors may secrete growth hormone-releasing hormone (GHRH), which tells the body to produce GH.
Sometimes, Acromegaly can be caused by an increased growth hormone production from outside the pituitary gland, such as from neuroendocrine tumors like small cell lung cancer or carcinoid tumors.
The pituitary gland is a small gland located deep within your skull under the main part of your brain. It produces several different hormones, including GH.
Because the pituitary gland is responsible for the production of the hormones that signal your body to grow, the pressure that is applied to this gland by a tumor, it stimulates the liver to produce too much IGF-1, which causes excess tissue growth.
Acromegaly is a rare condition. It can affect people of any age, but is most often diagnosed in adults aged 40-45 years.
Most people do not know they have Acromegaly until their condition has advanced. Signs of Acromegaly often develop so gradually that they go unnoticed for years or even decades. One of the most common symptoms of Acromegaly you can watch for is the enlargement of your hands and/or feet. You may notice that your rings are becoming too small, a sign that your hands are growing larger, or that you may need to buy larger shoes.
It is common for the jaw, forehead, and other parts of the face to enlarge. This is a visible and noticeable change to your appearance, but since it happens slowly over time, many people, including your primary care doctor, may not notice without comparing old photographs to your current state. Often, a friend or relative you haven’t seen in a few years or a new consulting doctor notices the change.
Many of the symptoms result from the enlargement of tissues caused by excess GH and IGF-1 in the blood.
- Arthritis, back pain, spine curvature (kyphosis) – due to enlargement of your bones and cartilage in joints
- Swelling of your face, lips, and tongue
- Breathing problems during sleep – due to narrowing of your airway resulting from swelling
- Tiredness during the day – due to poor sleep
- Your skin thickens
- You experience overly oily skin or acne
- Increased sweating
- Tingling or numbness in your fingers or toes – due to entrapment of nerves by enlarging muscles
- Change in bite or chewing, or spreading out of teeth – due to enlargement of your jaw and other facial bones
- Large numbers of skin tags
- Vision loss, partial or complete
These symptoms are caused not by the Acromegaly itself, but by the pituitary tumor. These tumors are almost always benign, meaning that they do not spread to other parts of your body. However, they can cause problems as they grow. They press on surrounding areas of your brain, blood vessels, and nerves. For example, they can press on your optic nerve, causing vision problems. Pressure on other nerves can cause headache. The size of the tumor determines whether these symptoms occur and how severe they are.
Pituitary tumors also can damage the gland itself, disrupting your hormone production. The resulting hormone imbalances are responsible for symptoms such as impotence, low sex drive, and changes in your menstrual cycle.
The tumor causes the gland to produce too much growth hormone. This, in turn, stimulates the liver to produce too much IGF-1, which causes the excess tissue growth.
Gigantism is the name used for Acromegaly in children. Because children’s bones are still growing, more of their bones are affected by the condition. The “long bones” of their arms and legs are particularly likely to grow more than usual. Children with Acromegaly often grow very tall.
Acromegaly can cause enlargement of your organs such as your heart, thyroid gland, liver, and kidneys. Untreated, Acromegaly is linked to early heart disease, high blood pressure, heart rhythm disorders, diabetes, and colonic polyps, a precursor of colon cancer.
People with Acromegaly have almost twice the chance of dying prematurely as the general population. Successful treatment, however, will restore near-normal health in most individuals.
Acromegaly that affects the heart or blood pressure or causes diabetes may have the following symptoms, although they may not occur in everyone with Acromegaly.
- Increased thirst or urination
- Shortness of breath
- Chest pain
- Palpitations or rapid heart beat
- Poor exercise tolerance
Acromegaly itself is usually not fatal. The complications of Acromegaly, such as heart problems, high blood pressure, and diabetes, can be life-threatening. Successful treatment of Acromegaly, however, will usually restore normal health.
Acromegaly is not an easy diagnosis, and it is frequently missed by doctors. Some of the signs and symptoms of Acromegaly are very distinctive. Others are subtle and can be missed or misinterpreted. Symptoms are not always recognized as Acromegaly because they develop so slowly. Once the diagnosis is suspected, you are usually referred to a specialist in hormonal disorders (endocrinologist).
Blood tests are used to help confirm your diagnosis. Measurement of IGF-1 level is considered the most reliable test for Acromegaly. Another test measures levels of IGF-binding protein-3 (IGFBP-3), a protein that interacts with IGF-1. This test is usually used to help confirm the diagnosis of Acromegaly.
Some health care providers measure how suppressible diabetic glucose levels. Blood glucose (sugar) suppresses growth hormone. The level of growth hormone in your blood is measured after you drink a sugary drink. The resulting high blood sugar level suppresses the growth hormone level in healthy people but not in people who have too much growth hormone.
A CT scan or MRI of the head is done to look for a pituitary tumor.
Treatments for Acromegaly do work in a significant proportion of people. Unfortunately, however, the disorder is rarely caught early enough to prevent permanent damage or even premature death.
Bone changes of Acromegaly are permanent. Many of the soft-tissue changes, such as swelling, enlarged tongue, thickened skin, acne, carpal tunnel syndrome, goiter, and sexual problems are reversible with treatment.
Complications such as high blood pressure, diabetes, and high triglycerides start to reverse when your levels of GH and IGF-1 are normalized. Correction of these complications can prevent more serious illness, such as stroke, heart disease, and death.
There are several treatment options in Acromegaly. Whichever treatments are used, the goal is to relieve and reverse the symptoms of the disease. This is done in two ways: by normalizing your GH and IGF-1 production and by reducing the effects of your pituitary tumor on surrounding tissues. A secondary goal is to avoid damaging normal pituitary tissue. The treatments that are used for a specific individual depend on the cause of your Acromegaly. For the large majority of cases caused by pituitary adenomas, treatments include surgery, drug therapy, and radiation therapy.
Surgery is usually the first approach to treating Acromegaly if it is discovered that you have a pituitary adenoma and it qualifies for removal. There are several factors that go into deciding whether or not a tumor is operable including, size, location, and accessibility. Since the removal of these types of tumors instantly relieves the pressure applied to your pituitary gland, it is the most effective treatment in most cases and offers hope for a cure. By removing your tumor, you will stop the overproduction of GH and other growth-stimulating hormones once the pressure has stopped being applied to your pituitary gland. The tumor is removed through an incision inside the nose. The operation is called transsphenoidal hypophysectomy. While technically not “brain surgery,” this is a very delicate operation calling for an experienced surgeon.
Surgery alone does bring about remission for most patients. “Remission” in this case means to return levels of GH and IGF-1 to normal. Remission is different than a cure in that the condition could return in the future. Transsphenoidal surgery is a safe, effective and relatively quick operation that can immediately relieve your symptoms. Remission rates are significantly higher in GH secreting pituitary macroadenomas than other hormone-secreting pituitary tumors.
If your Acromegaly goes into remission after surgery, there is usually no need for further treatment. (Some people, however, require lifelong hormone replacement after pituitary surgery.) GH and IGF-1 levels after surgery will indicate whether or not you need to continue to manage your symptoms with other treatments such as drugs and radiation. If these levels have not returned to normal, it is likely that you will require additional treatment.
The three types of medications that treat the symptoms of Acromegaly fall into three categories: Growth hormone receptor blockers, Somatostatin analogs, and dopamine antagonists.
Growth hormone receptor blockers represent the newest category of drugs for the treatment of Acromegaly. These drugs block the places on cells where growth hormone “docks.” If the excess growth hormone in the blood can’t dock on a cell, it can’t cause abnormal growth of the cell.
Pegvisomant, the only U.S. Food and Drug Administration-approved treatment for Acromegaly normalizes IGF-1 level in over 90% of people.
Somatostatin analogs act like a natural hormone, which stops the secretion of growth hormone. Octreotide, the most common drug in this group, works in most people who take it. You must inject yourself with this medication either three times per day under the skin or once per month in the muscle.
Dopamine agonists stop the secretion of growth hormone by stimulating dopamine (a chemical in the brain) activity.
Cabergoline continues to gain popularity due to the fact that its oral route administration and lower price tag than hormone receptor blockers or somatostatin analogs.
No one series of therapies works best for everyone and a combination of treatments is necessary for the remission of Acromegaly.Usually, surgery for removal of the hormone-secreting tumor is the first step in treatment.
Drug therapy is available to treat the symptoms of Acromegaly and shrink tumors in preparation for surgery. Some drugs block the production of growth hormones while others prevent GH from stimulating the production of IGF-1.
The final treatment option for symptoms of Acromegaly that persist after surgery and drug therapy is radiation.
Radiation is often the first treatment for people who cannot undergo surgery because of other medical conditions or the size and/or the location of their tumor.
A majority of people who undergo radiation therapy permanently lose function of their pituitary gland. These people must take hormone replacement for the rest of their lives. Drug or radiation therapy usually goes on for years. Radiation therapy can take anywhere from 18 months to several years.
Signs and symptoms of Acromegaly reverse or disappear in remission. Although cures for Acromegaly can be a lifelong condition.
Surgery can remove your hormone-secreting tumor completely or partially. Even after surgery, you may require additional therapies.
Drug therapy, an effective way to treat the symptoms of Acromegaly before and after surgery, can shrink tumors in preparation for surgery. Some drugs block the production of growth hormones, others prevent growth hormone from stimulating the production of IGF-1, and via dopamine, stimulation stops GH production in people with Acromegaly.
Drug and/or radiation therapy typically goes on for several years. Even after successful therapy, you may want to see your health care provider regularly to check your GH and IGF-1 levels.
To send Acromegaly into remission, care providers prescribe a combination of treatments since no one series of therapies works best for everyone and
Radiation serves as the final treatment option for the treatment of the symptoms of Acromegaly that persist after surgery and drug therapy.
Radiation can be the first treatment for patients who cannot undergo surgery, due to the size and/or the location of their tumor and offers a solution for patients with other medical conditions that interfere with the surgery or the size and/or the location of their tumor.
The majority of people who undergo radiation therapy permanently lose function of their pituitary gland. These people must take hormone replacement for the rest of their lives. Drug or radiation therapy usually goes on for years. Radiation therapy can take anywhere from 18 months to several years.
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