If you have cystic fibrosis, you will need to be screened for cystic fibrosis related diabetes (CFRD). We will ask you to complete a 2-hour oral glucose tolerance test. Please read these instructions.
Do not do this test if you are sick or taking oral steroids. Inhaled steroids, such as Advair® are okay.
How the Test Works
This test involves drawing blood twice over a period of two hours to measure how your body removes glucose (a kind of sugar) from the blood after drinking a sugary drink.
Reasons for Test
People with CF may have trouble making insulin or using the insulin their body makes. This could lead to CFRD or impaired glucose tolerance (IGT).
High glucose levels can lead to:
Weight loss
Trouble gaining weight
Drop in lung function
Other long-term health problems
Fasting Before Test
You must be fasting for at least 8 hours before this test. During this time:
Do not eat or drink anything except plain water.
Do not drink coffee, tea, soda (regular or diet) or any other drinks.
Do not smoke, chew gum (regular or sugar-free) or exercise.
Length of Test
The test takes about 2 hours. You must remain onsite (in the lab, clinic room, waiting room) for the entire 2 hours.
What to Bring
When you come for the test, we suggest you bring:
A book or laptop, or something else to do.
Food for after the test. We suggest a protein bar, nuts, or fruit.
Day of the Test
Fasting blood draw: You will first have a fasting blood sample taken when you arrive at the lab.
Get glucose drink: 1 bottle of the 75-gram glucose drink from the lab staff.
Drink the solution: As instructed. Do not eat or drink anything else.
Wait 2 hours: Remain in the lab/clinic for the next 2 hours. During this time:
Do not eat or drink anything.
Do not exercise or exert yourself.
Tell staff if you feel ill or need help.
Final blood draw: After 2 hours, have your second (and final) blood sample drawn.
After the Test
After the test, you may eat and drink as normal. Resume taking any medicine you may have stopped.
Results
The CF team will share the results of this test with you.
Who to Call
UW Adult CF Clinic nurse
608-262-9382