Glucagon Stimulation Test

Why am I having this test?

Your doctor has suggested that you have a Glucagon Stimulation Test, to check that you are able to produce enough cortisol and/or growth hormone.

The pituitary gland regulates the release of both cortisol and growth hormone. The best way to determine if you have a deficiency (lower than normal amounts) of either of these hormones is to stimulate the pituitary gland.

In order to do this, it is necessary to carry out a Glucagon Stimulation Test.

Cortisol is vital for life and we all need it:

• to keep our blood sugar levels stable
• to maintain blood pressure within normal limits/range
• for our metabolism (which is how we turn our food into energy)
• for our immune system (which protects us from infection)
• for our fluid balance (which makes sure that our body has the right amount of water)

Growth hormone is needed:

• for building and repairing cells, which are the building blocks of our bodies

If you do not have enough cortisol or growth hormone, you may feel tired, weak and irritable.

Who carries out this test?

A nurse who specialises in endocrinology (endocrine nurse) is responsible for carrying out this test.

Where is the test carried out?

• You will be sent a letter with details of the test and which department you will need to attend.
• If you wish you may bring a companion with you. They may stay with you during the test

How long will the test take?

• The test usually takes approximately 4 hours to complete.
• You may wish to bring a book, magazine or activity with you.

What do I need to do before the test?

• If you are taking the contraceptive pill or hormone replacement therapy [HRT] it may be necessary to stop these 8 weeks prior to the test, as it interferes with the interpretation of the result. If you are taking either of these treatments, please let the endocrine nurse know as soon as possible. You will need to use an alternative method of contraception during this time.
• If you are pregnant or think that you may be pregnant, please let the endocrine nurse know as soon as possible.
• If you have diabetes, please inform the endocrine nurse prior to attending for the test.
• If you are taking hydrocortisone tablets, steroid inhalers, steroid nasal sprays or steroid creams, you may be asked to stop these prior to the test, as these may interfere with the test results. Please see your appointment letter for further details.
• If you are unsure about any medicines you are currently taking, please contact the endocrine nurse.

What do I need to do the day before and the day of the test?

• Please have nothing to eat from 10.00pm the evening before the test. You may drink plain water freely.
• If you have diabetes and we have had to adjust your medication, you should not drive on the day of the investigation.
• Please bring all your medicines with you.
• Please carry on taking any other medicines that you are already on, unless we have specifically requested you not to.

What happens during the test?

• On arrival you will meet the endocrine nurse who is responsible for the test. The nurse will explain the test and you will be given the opportunity to ask questions prior to the start of the test.
• A cannula, which is a fine plastic tube, is placed into a vein in your arm and this is used to take blood samples. There may be some discomfort for a few seconds.
• You will then be given an injection of a drug called Glucagon into your bottom by the endocrine nurse. This acts as a stimulus to the pituitary gland and should cause cortisol and growth hormone to be released.
• Once you have been given the glucagon blood samples are taken at regular intervals from the cannula.
• Your blood pressure will be checked as appropriate during the test.
• At the end of the test the cannula will be removed and a small dressing applied. The dressing can be removed when you get home.

Are there any side effects?

• It is necessary for you to remain on a bed or a couch, as side effects of the drug may cause nausea, vomiting, tiredness and feeling cold.
• There is also a small possibility of a rapid heartbeat for a short time after the injection has been given.
• These side effects soon settle down naturally.
• If you experience any of these side effects, please inform the nurse who is in charge of the test.

What happens after the test?

• On completion of the test you will be safe to resume your daily activities.
• If you have been asked to stop any medicines prior to the test, the endocrine nurse will advise you when to restart the medicines.
• The results will be discussed at your next clinic visit or a letter will be sent to you and your GP.
• The endocrine nurse looking after you will arrange a further appointment as required.

If you require more details please contact the Specialist Nurses in Endocrinology:
Tel: 01274 382019 Monday – Friday between 8.00am and 4.00pm except Bank Holidays