IGF-1 generation test

What is an IGF-1 generation test?

An ‘insulin-like growth factor-1’ (IGF-1) is made by your body when growth hormone is released.

Growth hormone is produced by the pituitary gland, a small gland in your brain. Growth hormone is an important hormone for growth, but it also works by telling the liver to produce another hormone called IGF-1 that is also important for promoting growth.

In rare cases, children can produce enough growth hormone from the pituitary gland, but the body is unable to respond to growth hormone. This condition is called growth hormone resistance. Because the liver will not be able to respond to the growth hormone signal, it cannot produce enough IGF-1. This will lead to poor growth.

This test will show how much IGF-1 you are able to make, to decide if growth hormone resistance is the cause of poor growth.

How does the IGF-1 test work?

You will have 2 appointments on different days for this test

In this test we will check the levels of IGF-1 after an injection of growth hormone.

On your first appointment we will take blood sample, and tell you how to inject yourself with growth hormone at home.

At your second appointment we will take another blood sample to see how your body reacted to these injections.

The easiest way to do blood samples is with a cannula. This is a little plastic tube we put into the back of your hand or arm.

We will give you a local anaesthetic cream or cold spray to help stop any pain and discomfort. Please arrive 30 minutes earlier than your appointment time to allow for this cream to work.

Please allow enough time to attend the hospital for this test, particularly at your first appointment as you will need to be trained to give a growth hormone injection at home

What about my medications?

If you have any prescribed medications, they should be taken as normal before you come in. Please double check this with your doctor if you are not sure.

What happens after my test?

You will be able to go home once you have fully recovered from the test and are feeling well. If you are having any headaches from this test, please contact the Endocrine nurse on 0114 226 7815.

When will my results come back?

The results take around 1 month to be analysed. Your consultant might write to you with the results or want to talk about them with you at your next appointment.

What happens if I cannot make my appointment?

Please make every effort to attend the appointment. If the date or time you have been given is not convenient or your child is unwell, please contact the Endocrine nurse on 0114 226 7815.