Having a Glucose Tolerance Test

Before Your Test
You need an appointment to have a glucose tolerance test. Please call one of the following testing locations for an appointment. 

If you need a map to any of the locations, click here.

Fast before your test.
Do not eat or drink anything for 12 hours prior to the test, and do not eat anything during the test. Consult your physician if you are taking any medication. Several drugs may cause glucose intolerance, including the following:
           • Thiazide diuretics (e.g., hydrochlorothiazide)
           • Beta-blockers (e.g., propranolol)
           • Oral contraceptives 
           • Corticosteroids (e.g., prednisone)
           • Some psychiatric medications 

Interfering factors:
Before having the glucose tolerace test test, let your health care provider know if you are under an acute amount of stress (for example, from surgery or an infection), or if you have recently participated in vigorous exercise.  These factors may interfere with your test outcome.     

What to bring
     • The filled out WakeMed Physician Order Form
     • Your insurance card and information
     • Any papers your doctor tells you to bring

When you arrive
When you arrive for your test, please report to Patient Registration first. At Patient Registration, you will be asked for information that is required for our records and for insurance billing purposes.

What is a Glucose Tolerance Test?
The glucose tolerance test measures the body's ability to metabolize glucose (sugar).

How is a Glucose Tolerance performed?
The most common glucose tolerance test is the oral glucose tolerance test (OGTT). After an overnight fast, blood is drawn from the patient.  The patient then drinks a solution containing a certain amount of glucose, and blood is drawn again every 60 minutes after the glucose is consumed for up to 3 hours. The duration of the test will depend upon the physician's orders. You will not be permitted to eat, drink or smoke for the duration of the test.  Please remain in the testing area for the entire test.

Will the test hurt?  
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

When can I get my results?
The results of the test will be sent to the physician that requested the test. Your physician will discuss them with you. Laboratory employees are not permitted to release test results to patients.