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What is acromegaly?

Acromegaly is a rare condition. It is 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 stimulating metabolic changes that can result in other conditions such as diabetes.

What causes acromegaly?

Some of the cells in the pituitary gland which normally produce growth hormone start to divide more rapidly 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 occur so slowly, the condition can remain undiagnosed for many years.

What is the pituitary gland?

The pituitary is a very small gland, about the size of a cherry and produces some of the body's most important hormones. It is found beneath the base of the brain, just behind the bridge of the nose in the middle. Despite being very small, the pituitary gland is an extremely important structure and plays a key role in the body's hormonal system. It is responsible for producing and controlling many of the hormones that are responsible for growth and development, sexual maturation and reproductive function, and breast feeding in women.

Your pituitary gland also controls 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 natural 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 salt and mineral balance.

Is acromegaly common?

Acromegaly is thought to affect approximately 2,000 to 2,500 people in Great Britain, although recent data suggest the numbers may be higher. 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?

Acromegaly is not usually thought to be hereditary, although there are some rare, isolated instances of so-called 'familial' acromegaly where the condition has occurred amongst members of the same family.

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 and your shoes may feel too small. 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.

What are the symptoms of acromegaly?

The excess release of growth hormone results in the growth of soft, as well as bony tissue.

The many different signs and symptoms of acromegaly are listed below. You may find that you experience some, but occasionally none, of these symptoms.

Signs and 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 (poor breathing at night leading to snoring and frequent waking)
  • Some loss of vision
  • Irregular or absent periods
  • Erectile failure ('impotence')
  • Reduced fertility
  • Decreased sex drive

The metabolic changes caused by too much growth hormone can result in conditions such as diabetes and high blood pressure. 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 rest of 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. An endocrinologist is a doctor that specialises in hormone-related conditions.

The diagnosis of acromegaly is then relatively straightforward. Blood samples will be taken so that simple tests can be done to measure your growth hormone and IGF-1 (a hormone that is produced in response to growth hormone) levels, and also to test whether or not your pituitary gland is functioning normally.

Two 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 ('sugary') drink. Further blood samples will be taken every 30 minutes over a period of about two hours. After this, you will 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 to very low levels.

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 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

Insulin-like growth factors (IGFs) are naturally occuring compounds produced mainly by the liver, but also by many other tissues, that mediate the typical growth hormone responses on cartilage, bone, muscle and fat tissues. Some of the blood you provide for the growth hormone test may also be used to assess your IGF-1 levels.

When will I get the results of the tests?

The results of the tests will usually be available in about one week, but this may vary from one hospital to another and may take up to two to three weeks.

Are there any other tests used to diagnose acromegaly?

Magnetic Resonance Imaging (MRI) or Computerised Tomography (CT) 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 be carried out without you having to stay overnight in the hospital, although if you live a long way from the hospital it may be convenient to stay overnight.

What are the aims of treating acromegaly?

The main aims of treatment are to remove or reduce the size of the adenoma if possible, and also 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 looser and your shoes and gloves may fit more comfortably), and the sweating should markedly improve. Over time other symptoms such as headache and bony changes 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.

What does surgery involve?

For most people with acromegaly, surgery to remove or reduce the size of the tumour is usually the first approach. This can dramatically reduce the growth hormone 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 to two hours 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 depends on the size and position of the tumour. If the tumour is small and completely accessible, surgery alone may be successful and no further treatment will be required.

Are there side-effects from the surgery?

Your surgeon will advise you about the possible complications which sometimes occur from the surgery. For example, sometimes the operation may damage some other parts of the pituitary gland and this may cause a reduced production of some other hormones. If this occurs, you can take replacement hormone therapy. In addition, there may be side-effects from the general anaesthetic such as feeling sick after surgery, a sore throat and headache; but most people are not affected.

When is radiotherapy used?

If surgery is not completely successful at restoring growth hormone levels to normal, then radiotherapy may sometimes be used to further reduce the size of the tumour. In some instances, radiotherapy may be recommended instead of surgery.

Radiotherapy is effective but the irradiated tumour cells die very slowly over a period of many months or years. In the meantime, growth hormone and IGF-1 levels may have to be controlled with medical treatments (see later).

External beam radiotherapy

The radiotherapy treatment most frequently used is an external beam.

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.

Radiosurgery

Another approach is radiosurgery e.g. gamma-knife, which uses a highly-focussed single beam of radiation given as one, single dose to the tumour cells.

A lightweight head frame is used to ensure that the radiation beams are directed with precision to the tumour. The frame is held in position with four pins; a local anaesthetic is applied to the area where the pins are to be attached.

The treatment involves lying on a treatment couch which then moves into a machine which will deliver the radiation treatment. The treatment will last between a few minutes to more than an hour depending on the size and shape of the tumour. The treatment is silent and totally painless.

Are there side-effects from radiotherapy treatment?

A possible side-effect of pituitary radiotherapy is damage to other normal pituitary cells. This can cause a decreased level of some other hormones. However, if this does occur, you can take replacement hormone therapy.

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.

Although you will feel no discomfort or pain during external beam radiotherapy, you may feel tired and although some people continue to work, this may not always be possible.

With radiosurgery, some patients experience a mild headache or minor swelling where the head frame was attached, but most report no problems.

What is the role of medical treatment?

Medical treatment is used to keep growth hormone levels within the normal range, or to prevent growth hormone exerting its effect on the body.

It may be used after surgery and/or radiotherapy to reduce growth hormone and IGF-1 levels further, and also 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 cabergoline are sometimes used. They prevent the release of growth hormone by stimulating dopamine receptors on the surface of the tumour. Although they may be effective in some people with acromegaly, they are generally less effective than somatostatin analogues. Because some people taking much larger doses of cabergoline have developed heart-valve problems, you may be asked to have a special scan of your heart valves; this is called an echocardiogram. However, there is little evidence that any person taking cabergoline for acromegaly has shown heart valve damage.

Somatostatin analogues

Somatostatin is a naturally occurring hormone that stops the release of hormones and other chemicals in our body. In acromegaly synthetic versions, or 'analogues', of somatostatin are used which reduce the release of growth hormone. Examples of these are lanreotide, octreotide and pasireotide. Pasireotide is licensed for patients who are not sufficiently well controlled on treatment with octreotide or lanreotide.

Growth hormone receptor antagonist

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 reducing IGF-1 hormone levels. It is licensed for use when surgery, radiotherapy and other medicines have not been completely successful in controlling acromegaly.

How are these medicines given?

Dopamine agonists

The dopamine agonists are available in tablet form. They are taken at least once a week but more usually on several days each week.

Somatostatin analogues

Octreotide can be given as a short-acting injection two to three times a day, or as a long-acting injection administered by a healthcare professional every 28 days. The short-acting form is injected into the tissue under the skin, either in the upper arm, thigh or stomach. The long-acting form is injected in the large muscle in the buttock.

Lanreotide can be given as an injection every 7-14 days or as a long-acting injection every 28 days. For some patients who are stabilised on their treatment with lanreotide, one strength of the injection may be given every 42-56 days. The long-acting injection can be administered by a nurse, either in hospital or by a practice nurse. For some patients who are stabilised on their treatment with lanreotide, it may be possible for the patient, or a relative/friend, to be taught how to give the injection themselves. The injection is given in the upper, outer quadrant of the buttock, or if you are self-injecting, into the upper thigh.

Pasireotide is administered by a healthcare professional every 28 days into the the large muscle in the buttock.

Growth hormone receptor antagonist

The growth hormone receptor antagonist pegvisomant is given as an injection once a day just under the skin

Are there side-effects with the medical treatments?

All medicines have side-effects and many wear off with time. However, it is important to read the patient information leaflet inside the medicine pack. All side-effects should be reported to your health professional so that if necessary, they can be passed on to the manufacturer of the medicine or to the Department of Health.

You should also report side effects online at www.mhra.gov.uk/yellowcard

Dopamine agonists

Feeling sick is a common side-effect of a dopamine agonist. In addition, other side-effects include headache, drowsiness and constipation, although all are uncommon.

Somatostatin analogues

The most common side-effects of lanreotide and octreotide are diarrhoea, abdominal pain and feeling sick, but these usually wear off with time. In addition other common side-effects include constipation, flatulence, bloating, gallstones and pain at the injection site.

Pasireotide has a similar side effect profile to lanreotide and octreotide but is also associated with a higher degree and frequency of elevated blood glucose levels.

Growth hormone receptor antagonist

The most common side-effects with a growth hormone receptor antagonist are injection site reactions, sweating, headache and muscle weakness. Your doctor will check your blood at intervals for liver function as well.

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) may be appropriate.

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 radiotherapist 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.

The medical treatments are suitable for administration in the community and your GP and or practice nurse will usually be involved in this part of your treatment. They will also be available to guide and support you.

It may seem that you have been passed from doctor to doctor, but this multidisciplinary approach is the recommended 'gold standard' for managing your condition, and ensures that you receive the most appropriate expert care.

How often will I see my doctor?

It is important that your growth hormone and IGF-1 levels are monitored to ensure your treatment is having the desired effect, so it will be necessary to have regular appointments at the hospital.

Can I lead a normal life during my treatment?

Many people with a diagnosis of acromegaly will have lots of questions that they want to ask and often have concerns that need to be addressed. However, 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 this information, 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 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 are listed below.

What if I get worried or concerned?

If you have any concerns or worries ask either your nurse, your hospital doctor or your GP.

Make the most of your visits with your doctor. 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 my lifestyle?

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 Pituitary Foundation is a UK organisation for people with pituitary conditions and can be contacted at:

The Pituitary Foundation
PO Box 1944, Bristol BS99 2UB
Tel No: 0845 450 0375
Email: helpline@pituitary.org.uk
Website: www.pituitary.org.uk