Glucose Tolerance Test (GTT)

An appointment is required for this test. Please phone your nearest Laverty Pathology Collection Centre to make arrangements. Collection Centres and the test availability can be found here.

We recommend the following pre-test preparation for optimal results:

1. NO diet is required for pregnant patients. We suggest you eat the type of foods you normally eat.
2. In non-pregnant patients, for the three (3) days before your test, you should eat “high carbohydrate” meals. We suggest you eat the type of foods you normally eat, but make sure that throughout the day you include in your diet all of the following foods:
   • 1 serving of breakfast cereal, porridge or spaghetti
   • AND 3 slices of bread or toast (or 1½ bread rolls)
   • AND 3 servings of vegetables
   • AND 3 pieces of fruit
   • AND 1 medium potato or 1 serving of rice.
   Children who are too small to be able to eat all of the above foods should eat whatever they can comfortably manage.
3. If you do not follow the diet, you will not be turned away, as it is more important that the test is performed. However, our clinic staff will be happy to re-schedule you if preferred.
4. You are required to fast for eight hours prior to the test – which usually means an overnight fast.
5. The maximum acceptable duration of a fast is fourteen hours – if the fast is longer than this, your referring doctor will be notified and consulted before the test is either rescheduled or carried out on the day.
6. During a fast, you must have nothing to eat or drink, except for water. NO soft drinks, tea, milk, coffee or fruit juice may be taken during the fast.
7. NO SMOKING on the day of the test and until the test is completed.

Information:

• On arrival at our Collection Centre, a blood sample will be taken from you by one of our trained collecting staff. You will then be asked to drink a sweet glucose drink and blood will be collected one and two hours later.
• Please note that you will be required to remain in the Collection Centre for the duration of the test. We suggest you bring a book to read to help pass the time.

Important: While on the 3-day high carbohydrate preparation, if you should become very unwell, or notice that you are losing weight, feeling drowsy, very thirsty and are passing large amounts of urine, please contact your referring doctor immediately.