Glucose Tolerance Test

The glucose tolerance test is done to help diagnose diabetes and growth hormone issues.

Why is this test being done?

This test is done primarily for two reasons:

  • to find out if a child has diabetes or
  • to find out if a child is producing too much growth hormone

By giving a very sugary drink, we can trigger the release of growth hormone and we can measure how the body uses glucose.

How is the test done?

We start by placing an IV line in your child’s arm. This is so we can collect several blood samples without having to poke your child each time. We measure the glucose levels from these blood samples. Next, your child is given the glucose (sugar) to drink. This drink is a sweet beverage and needs to be finished in 5 minutes. Then, blood is drawn through the IV every 30 or 60 minutes for 2 hours. Plan on being at Children’s the entire morning.

How do I prepare my child for the test?

  • Your child needs to be fasting before the test. This means that your child may not have any food or liquid other than water. Have your child fast for at least 6 hours before coming in for the test. Your child may still take their daily medicines as needed with small sips of water.
  • Your child should be feeling well and not have a fever the day of the test.
  • Bring books, toys or games for your child to pass time during the test. We have a TV and DVD player with a small selection of DVDs for your child to watch.

Will my child have pain?

In partnership with you and your child, we are committed to the prevention and relief of pain as completely as possible. Your child may feel pain or be uneasy with the needle pokes. You know your child best. No matter the level of their pain, believe they are hurting and respond right away.

Your child will not feel any side effects from this test except for mild discomfort or stiffness at the IV draw site.

Where do we go for the test?

This test is done in the Ambulatory Infusion Unit in Bellevue. Please contact the reception desk and someone will come out to meet you.

When will I get the results?

It takes 1 to 2 weeks to get the results back from the lab. Be sure your child has an appointment scheduled to meet with the endocrinologist 2 to 3 weeks after the test is done. They will review the results and talk with you about next steps for your child’s care. To schedule the appointment with the endocrinologist to get your child’s test results, please call 206-987-5610.