“I had blood tests and my insulin-like growth factor level was very high”
This patient testimonial reflects only this person’s opinions about their own care. Each person’s case is unique and you should always consult a doctor for information and advice about the diagnosis and treatment of acromegaly.
Please note that the tests used to diagnose acromegaly may vary according to your particular situation.
The oral glucose tolerance test, or OGTT, is generally done in the morning and will require you to fast for 8 to 10 hours before the test. This includes having no food or fluids such as tea, coffee or fruit juice. You may however have sips of water if you are thirsty.
When you go in for the test, a blood sample will be taken and you will be given a glucose (‘sugary’) liquid that you will need to drink within 5 minutes.
A blood sample will be collected 1 hour and 2 hours after you finished drinking the glucose liquid.
In people without acromegaly, the glucose in the drink will normally cause growth hormone levels to fall. If your body is making too much of the hormone, these levels will not go down enough, which helps confirm the diagnosis of acromegaly.
The three main elements of the oral glucose tolerance test
A reliable way to track growth hormone in the body is by measuring the level of IGF-1 (insulin growth factor) in the blood.
IGF-1 measurement is the most accurate screening blood test. In most cases, a high IGF-1 level suggests that you have acromegaly.
IGF-1 measurement is often done at the same time as an oral glucose tolerance test.
Learn about acromegaly including what causes this slowly evolving condition, and the early signs and symptomsLearn about acromegaly
Read about acromegaly treatment options, including surgery, medications and radiotherapy, and the goals of therapyTreating acromegaly
Read and hear answers to some common questions that patients with acromegaly have askedView FAQs