Understanding acromegaly
The information in this section is part of a comprehensive information pack for patients which is currently being updated.
What is acromegaly?
Acromegaly is a rare condition caused, in almost all cases, by the prolonged, excess release of growth hormone from the pituitary gland. This excess release of growth hormone promotes the growth of bone and soft tissues, as well as metabolic changes that can result in symptoms such as diabetes.
What causes acromegaly?
Some of the cells in the pituitary gland, which normally produce growth hormone, start to divide in a less controlled way than normal. The continued growth of these hormone-producing cells results in a pituitary "adenoma" or tumour. The tumour is almost always benign (not cancerous) and does not spread to other parts of the body.
In about one-third of people with acromegaly, the pituitary tumour also produces another hormone called prolactin.
Because the symptoms of acromegaly appear so slowly, the condition can remain undiagnosed for many years.
What is the pituitary gland?
The pituitary gland is very small. It can be found at the base of the brain behind the bridge of your nose. It is a very important gland because it is responsible for producing and controlling many of the hormones that determine growth and development, sexual maturation, reproductive function and breast feeding in women.
Your pituitary gland also controls the thyroid and adrenal function, which in turn control blood pressure, sleep cycles, the immune system, and the metabolism of proteins, carbohydrates, fats and water.
What is growth hormone?
The scientific name for growth hormone is somatotrophin. It is derived from the Greek words for body and nourishment. It has an effect on virtually all organs of the body in terms of growth, metabolism and overall quality of life.
When is growth hormone released?
Growth hormone is released throughout life in short bursts, typically when you are asleep.
What is the role of growth hormone?
Growth hormone affects fat cells and muscle. It also has a major effect on bone. When too much growth hormone is released, bone and tissues grow more than they should. Growth hormone is also important in many metabolic processes, for example protein, carbohydrate and lipid metabolism, and electrolyte and mineral balance.
Is acromegaly common?
Four to five new cases per one million of the population are diagnosed each year.
Acromegaly affects approximately 2,000-2,500 people in Great Britain. Men and women are affected equally. Although it can affect people at any age, most people with acromegaly are between 30 and 50 years of age when they are diagnosed.
Is acromegaly hereditary?
No it is not.
How will acromegaly affect me?
Acromegaly could affect you in different ways.
You may have noticed that your rings no longer fit your fingers. You may need larger-sized gloves. When you put on a hat in the winter, you may notice that it feels small. Your shoes may also feel too tight.
You may also suffer from headaches or excessive perspiration. You may just not feel very well. All of these symptoms develop gradually and you may not be aware of them for some time.
Diagnosing acromegaly
What are the symptoms of acromegaly?
The excess release of growth hormone results in the growth of soft, as well as bony tissue.
There are many different symptoms of acromegaly:
- - Enlargement of the hands, feet and head
- - Changes in facial features
- - Protrusion of the jaw
- - Excessive sweating
- - Tiredness and lethargy
- - Increased frequency and/or severity of headaches
- - Ear, nose (snoring), throat or dental problems
- - Thickening and oily skin
- - Enlarged thyroid gland
- - Enlargement of the tongue
- - Deepening of the voice
- - Joint stiffness, arthritis
- - Impaired glucose tolerance or diabetes
- - Tingling in the fingers and hands (carpal tunnel syndrome)
- - High blood pressure
- - Sleep apnoea
- - Some loss of vision
- - Irregular periods
- - Impotence
- - Reduced fertility
- - Decreased sex drive
Some of the symptoms, for example diabetes and high blood pressure, are a result of the metabolic changes caused by too much growth hormone. Other symptoms such as the headaches and loss of vision are a result of the benign tumour in the pituitary swelling and pressing on other areas in the brain.
The tumour can also squeeze the pituitary gland and prevent it from working properly. A deficiency of one or more hormones produced by the pituitary gland is called hypopituitarism.
What tests will be carried out to diagnose my acromegaly?
Your doctor will send you to see an endocrinologist at your nearest main hospital. This is a doctor who specialises in hormone-related conditions.
The diagnosis of acromegaly is then relatively straightforward.
Blood samples will have to be taken so that simple tests can be done to measure your growth hormone and Insulin-like Growth Factor 1 (IGF-1) levels and also to test whether or not your pituitary gland is functioning normally.
The following tests may be done to measure your growth hormone levels:
Oral glucose tolerance test
This test usually involves fasting from about 10pm the evening before an early morning appointment at the hospital. Blood samples are then taken every half an hour from a catheter (thin plastic tube) that is placed in a vein in your arm.
After the first blood sample you will be given a glucose drink. Further blood samples will be taken every 30 minutes over a period of about two hours. After this, you will usually be able to have some breakfast and go home.
If you have acromegaly, your growth hormone levels will remain high throughout the test. This will happen even after a glucose drink, which would normally result in the growth hormone levels decreasing.
Growth hormone profile/day curve
This test also involves fasting from about 10pm the evening before an early morning appointment at the hospital. A needle is placed in your arm and blood will be taken at intervals over several hours. After the first sample is taken, you can usually have breakfast and you will be able to move about freely.
If you have acromegaly, your growth hormone levels remain high throughout the day.
IGF-1 measurement
Some of the blood you provide for the growth hormone assessment may also be used to assess your IGF-1 levels.
When will I get the results of the tests?
The results of the growth hormone level tests will usually be available in about one week.
Are there any other tests used to diagnose acromegaly?
MRI or computerised tomography can provide useful information about the exact position and size of the tumour in the pituitary gland.
MRI scans are painless, but you have to lie very still on a couch inside the scanner for about 30 minutes. Some people can feel claustrophobic, especially as the scanner may make a lot of noise.
Do I have to stay in hospital when I have these tests?
No. These tests can usually be carried out without you having to stay overnight in the hospital.
Treatment and care
Will I have to have the tests regularly?
You are likely to have your growth hormone and IGF-1 levels measured when you attend the hospital for your routine appointment. This is the main way of ensuring that your treatment is having an effect.
What are the aims of treating acromegaly?
The main aim of your treatment is to reduce your growth hormone and IGF-1 levels to within the normal range. This will improve your symptoms and reverse the physical signs of acromegaly.
Within days of the successful reduction of growth hormone levels, soft tissue swellings may become reduced quite noticeably (for example your rings may become loose again), and over time other symptoms such as sweating and high blood pressure may decrease.
What are the treatment options?
There are three treatment options for people with acromegaly; surgery, radiotherapy or medical treatment. For some people a combination of all three is used:
Surgery
For most people, surgery to remove the tumour is the first stage in the treatment of acromegaly. This can dramatically reduce the growth hormone and IGF-1 levels, as well as easing some of the other problems caused by the presence of the tumour, such as headaches and visual problems.
Surgery is carried out by a pituitary surgeon who will make a small cut in your nose or mouth (called the transsphenoidal route). Doing the operation this way means that there is no visible scarring and your stay in hospital is short. The operation will normally take about one hour and you will be in hospital for about five days.
Very occasionally an operation through the skull (transcranial) may need to be done instead.
Whether it is possible to completely remove the tumour and restore growth hormone levels to normal will depend on the size of the tumour. If the tumour is small, surgery may be completely successful and no further treatment would be required.
Radiotherapy
If surgery is not completely successful at restoring growth hormone levels to normal, then radiotherapy may be used to further reduce the size of the tumour. In some instances, radiotherapy may be recommended instead of surgery.
Radiotherapy involves the use of external beam radiation and is planned and carried out with extreme care.
Small doses of radiation are given for a few minutes each day, for five days, usually for five to six weeks. The radiation beam is aimed with great precision from three directions at the tumour. A transparent mask will be made for you to prevent your head from moving during the procedure. Don't worry, the mask will have big holes for your eyes and mouth.
You will feel no discomfort or pain during this treatment. But you may feel tired and although some people continue to work, this may not always be possible.
Also, although the dose of radiation is relatively small, some people may lose some of their hair temporarily - but it does grow back after the treatment is finished.
Radiotherapy is effective, but the irradiated tumour cells die slowly over a period of months, even years. In the meantime, growth hormone levels may have to be controlled with medical treatments such as dopamine agonists or somatostatin analogues.
Medical therapies
Medical treatment is used to keep growth hormone and IGF-1 levels within the normal range.
It may be used after surgery and/or radiotherapy to reduce growth hormone and IGF-1 levels further and to control your symptoms. In some cases medical treatment can be given to help your symptoms before surgery or radiotherapy. Occasionally, surgery may not be suitable for some people and they may receive long-term medical treatment instead.
What medicines are used?
There are three groups of medicines used:
Dopamine agonists
Dopamine agonists such as bromocriptine are sometimes used. They prevent the release of growth hormone by binding to dopamine receptors on the surface of the tumour. Whilst they may be effective in some people, they are generally less effective than somatostatin analogues.
Somatostatin analogues
Somatostatin is a naturally occurring hormone that stops the release of hormones and other chemicals in our body. In acromegaly, it acts directly on the tumour, preventing the release of growth hormone. It is now possible to manufacture synthetic versions or "analogues" of somatostatin to use in medicines. Examples of these are lanreotide and octreotide.
Growth hormone receptor antagonists
Another type of medicine is available that prevents growth hormone from having its effect on the body. Although it does not have a direct effect on the tumour or the release of growth hormone, it is effective in treating the symptoms of acromegaly. Pegvisomant is the only growth hormone receptor antagonist currently approved in the UK and is recommended for use when other treatments have not been completely successful in controlling acromegaly.
Do these medicines have to be injected?
The dopamine agonists are available in tablet form.
The somatostatin analogues are given as an injection either three times a day, fortnightly or monthly. The monthly formulations are becoming most popular in terms of convenience for the patient. Many people now receive their somatostatin analogues each month at their GP's surgery.
The growth hormone receptor antagonist is approved as a daily injection.
Do I need any hormone replacement treatment?
People with acromegaly can develop a loss of normal pituitary function either because of the pituitary tumour or its treatment. This means that patients need to be continually monitored and, if there is a problem, replacement hormones such as hydrocortisone (or cortisol), thyroxine, testosterone (in men) and oestrogen (in women) can be used.
Who will give me my treatment?
Your GP will have referred you to a hospital doctor, called an endocrinologist. If surgery is required, the endocrinologist will involve a pituitary surgeon or neurosurgeon. If radiotherapy is required then a radiologist will be involved in your treatment. The endocrinologist will decide what medical treatment you require. There will be an endocrine nurse to help and support you in hospital. Your GP and or practice nurse will also be available to guide and support you.
It may seem that you have been passed from doctor to doctor, but it is important that you receive the most appropriate expert care.
How often will I see my doctor or nurse?
It is important that your growth hormone and IGF-1 levels are monitored, so it will be necessary to have regular appointments at the hospital.
Self-help and support
Can I lead a normal life during my treatment?
Yes. Many people are able to continue to work and maintain a relatively normal life during their treatment. For those people who may feel vulnerable and alone, there is always help and support available.
How can I help myself?
Many people find it useful to know as much as they can about their condition and its management.
As well as the information provided in this resource, the Pituitary Foundation provides a series of booklets about various conditions including acromegaly, with advice and information on life insurance, entitlement to free prescriptions, pension arrangements, employment issues, travel arrangements and much more.
In addition, a newsletter is available four times a year and a nurse counsellor is available on their helpline to answer your questions.
The Pituitary Foundation also runs local support groups - you may find it useful to belong to one in your area.
The contact details of the Pituitary Foundation can be found below.
What if I get worried or concerned?
If you have any concerns or worries ask either your nurse or the hospital doctor.
Make the most of your visits with your healthcare team. The more you understand about your condition, the more in control you will feel. Take a list of the questions you have to your next hospital appointment and make notes of the answers.
Or take a partner or friend with you so that they can remind you about the questions you need to ask. They will also help you to remember comments from the doctor and nurse after your visit.
Do I have to change what I eat?
Some people use their diagnosis as a spring-board to a healthier lifestyle. They may stop smoking, cut down on alcohol and make a conscious effort to eat more fruit and vegetables and less fatty foods. Following a healthy diet and if possible, regular, gentle exercise may help you to feel better.
Taking a positive attitude may also help your progress.
What patient organisations are there?
The main patient organisation is the Pituitary Foundation:
The Pituitary Foundation
PO Box 1944, Bristol BS99 2UB
Tel/Fax No: 0845 450 0375
Email: helpline@pituitary.org.uk
Website: www.pituitary.org.uk
