- What Is It?
- Pituitary Gland
What is acromegaly?
- Acromegaly is a serious condition that occurs when the body produces too much of the hormones that control growth.
- This causes abnormal enlargement of bone, cartilage, muscle, organs, and other tissues.
- This abnormal growth can cause serious disease and even premature death.
What is a hormone?
- Hormones are natural chemicals made by various organs. Hormones control many different functions in the body.
- Besides growth and development, they also control metabolism and reproduction and influence emotions.
- They affect just about every system of the body.
What causes acromegaly?
- Acromegaly occurs when the body produces too much of any of the hormones that control growth.
- These include growth hormone (GH), growth hormone-releasing hormone (GHRH), and insulin-like growth factor 1 (IGF-1).
- Overproduction of these hormones is caused by certain types of tumors.
- In most cases, the tumor is an adenoma of the pituitary gland.
How does a tumor in the pituitary gland cause abnormal growth elsewhere?
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.
How common is acromegaly?
Acromegaly is a rare disease. It can affect people of any age, but is most often diagnosed in adults aged 40-45 years.
How do I know if I have acromegaly?
Most people do not know they have acromegaly until the disease is advanced. Signs of acromegaly often develop so gradually that they go unnoticed for years or even decades.
The most common symptom is an enlargement of the hands or feet. You may notice that your rings are becoming too small, a sign that your hands are growing larger. You may need to buy larger shoes.
Your jaw, forehead, and other parts of the face also may enlarge. This changes the way you look. Because this growth happens slowly over time, many people, including your primary care doctor, may not notice the change in your appearance. Often, a friend or relative you haven’t seen in a few years or a new consulting doctor notices the change.
What are other symptoms of acromegaly?
Many of the symptoms result from the enlargement of tissues caused by excess growth hormone and IGF-1 in the blood.
- Arthritis, back pain, and curvature of the spine (kyphosis) - Due to enlargement of bones and cartilage in joints
- Swelling of the face, lips, and tongue
- Breathing problems during sleep - Due to narrowing of the airway resulting from swelling
- Tiredness during the day - Due to poor sleep
- Thickening of the skin
- Oily skin or acne
- Increased sweating
- Tingling or numbness in the 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 the jaw and other facial bones
- Large numbers of skin tags
- Vision loss, partial or complete
Why does acromegaly cause vision loss and headache?
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 the body. However, they can cause problems as they grow. They press on surrounding areas of the brain, blood vessels, and nerves. For example, they can press on the 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 hormone production. The resulting hormone imbalances are responsible for symptoms such as impotence, low sex drive, and changes in the menstrual cycle.
What is gigantism?
Gigantism is the name used for acromegaly in children. Because children’s bones are still growing, more of their bones are affected by the disease. The “long bones” of their arms and legs are particularly likely to grow more than usual. Children with acromegaly often grow very tall.
What are the complications of acromegaly?
Acromegaly can cause the enlargement of body organs such as the 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. These do not occur in everyone with acromegaly.
- Increased thirst or urination
- Shortness of breath
- Chest pain
- Palpitations or rapid heartbeat
- Poor exercise tolerance
Is acromegaly a fatal disease?
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.
How is acromegaly diagnosed?
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. They 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 the 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 used sometimes to help confirm the diagnosis of acromegaly.
Some health care providers measure what is called “glucose nonsuppressibility.” 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.
What treatments are available for acromegaly?
There are several treatment options for acromegaly. Whichever treatments are used, the goal is to relieve and reverse the symptoms of the disease. This is done in 2 ways: by normalizing the production of growth hormone and IGF-1 and by reducing the effects of the pituitary tumor on the surrounding tissues. A secondary goal is to avoid damaging normal pituitary tissue.
Which treatments are used for a specific individual depends on the cause of the disease. For the large majority of cases caused by pituitary adenomas, treatments include surgery, drug therapy, and radiation therapy.
Will I have surgery?
Surgery is usually the first approach to treating acromegaly. For most people, this means the removal of the pituitary tumor that is causing overproduction of growth hormone. 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.
Is surgery a cure for acromegaly?
Surgery alone does bring about remission for some people, but not everyone. “Remission” in this case means to return levels of growth hormone and IGF-1 to normal. Remission is different than cure in that the disease can come back from remission.
If it is successful, this operation quickly relieves symptoms caused by the tumor pressing on adjacent tissue. Remission rates are high for small and large adenomas (microadenomas and macroadenomas, respectively).
People who are in remission after surgery usually need no further treatment. (Some people, however, require lifelong hormone replacement after pituitary surgery.) Growth hormone and IGF-1 levels after surgery usually indicate whether further treatment is needed. If these levels have not returned to normal, another treatment is needed.
What other treatments are available?
Often a combination of treatments is needed to put the disease in remission. No one combination of therapies works best for everyone.
Drug therapy is usually the second treatment. Drugs are given to normalize levels of growth hormone and IGF-1. Some drugs work by blocking the production of growth hormones. Others work by preventing the growth hormone from stimulating the production of IGF-1. In some cases, drugs are given to shrink the tumor.
Radiation therapy usually is reserved for adenomas that are not cured by surgery and drug therapy. Radiation also is used for people who cannot undergo surgery because of other medical problems. A majority of people who undergo radiation therapy have permanent loss of pituitary function. 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 to put the disease in remission.
What drugs are used to treat acromegaly?
Growth hormone receptor blockers are the newest category of drugs used for acromegaly. These drugs work by blocking 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. The only drug in this category that has been approved by the US Food and Drug Administration for acromegaly is pegvisomant (Somavert). In early studies, this drug normalized the IGF-1 level in more than 90% of people treated. Pegvisomant is given a shot every day.
Somatostatin analogs act like a natural hormone called somatostatin, which stops the secretion of growth hormones. The most widely used drug in this group by far is octreotide (Sandostatin). This drug works in most people who take it. It can be taken only as shots, either 3 times a day under the skin or once a month in the muscle.
Dopamine agonists promote the activity of dopamine, a chemical in the brain. These drugs work by stopping the secretion of growth hormones by some pituitary tumors. The most widely used of these drugs is bromocriptine (Parlodel). It is popular because it comes in a convenient oral form and is much less expensive than octreotide. These drugs generally do not work as well as the growth hormone receptor blockers or the somatostatin analogs.
Other questions about acromegaly
Can acromegaly be cured?
Acromegaly can be put into remission. This means that the disease is stopped and many of the signs and symptoms reversed. But, acromegaly can be a lifelong disease. Drug and/or radiation therapy typically goes on for several years. Even after successful therapy, you will need to see your health care provider regularly to have your growth hormone and IGF-1 levels checked.
How can acromegaly be prevented?
There is no known way to prevent acromegaly. Early detection is the best hope of preventing severe symptoms and complications.
What does it mean to live with acromegaly?
Treatments for acromegaly do work in a significant proportion of people. Unfortunately, however, the disease 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, and goiter, and sexual problems, are reversible with treatment.
Complications such as high blood pressure, diabetes, and high triglycerides start to reverse when the levels of growth hormone and IGF-1 are normalized. Correction of these complications can prevent more serious illnesses, such as stroke, heart disease, and death.
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"Causes and clinical manifestations of acromegaly"