Introduction
You have been asked to take a Glucose Tolerance Test because your doctor wants to see whether you have abnormal blood sugar levels in your blood, which might indicate whether you have diabetes or not.
For further details please see www.labtestsonline.org.uk which is written by practising laboratory doctors and scientists to help you understand the many clinical laboratory tests that are used in diagnosis and treatment.
The results for your test will be sent to your requesting doctor when complete.
Procedure
- You should be on your usual diet without carbohydrate restriction for at least three days prior to the test.
- You are required to fast for at least 8 hours for this test. This is to ensure that reliable results are obtained.
- On the evening prior to your appointment do not have anything to eat or drink after around mid-night. You can have small sips of water.
- Medication / tablets should be taken as normal. However, if you are pregnant and taking Gaviscon for heartburn please do not take any on the morning of the test as it affects the uptake of glucose, (Rennies are acceptable, but in moderation).
3. On the day of your appointment go along to the relevant testing centre. If you were given a Pathology request form for the Glucose Tolerance Test by your GP, take that along with you.
- The test can take up to 2 hours to complete, so please bring something to read to keep you occupied during the long wait between blood samples. Please bring a light snack (e.g. sandwich, banana or Muesli bar) with you to eat when the test is ended.
- In some cases it may be possible to end the test within less than an hour, i.e. we may have all the necessary information at that time. This is the exception rather than the rule, but you may like to make provision in your transport arrangements to take account of this.
4. Two or three blood samples will be collected: two by needle in a vein (venous) and one may be by finger prick. Once the result of the first blood sample is known, usually within 10-15 minutes, you will then be given a glucose drink (GlucosePro) which you should drink within 5 minutes (ideally). Note that if the result of the first (fasting) glucose is unequivocally high and indicative of diabetes, the test will be terminated, and you will not have to take the glucose drink.
5. After this there is a 2 hour wait before the second venous blood test.
- You should remain seated within the Unit Waiting area and must NOT eat, drink or smoke.
6. After the second blood sample has been collected you will be able to leave the department.
Failure to follow these instructions may cause invalid results or postponement of the test
Benefits
The benefit of doing the test is that it will provide your doctor with important results which will help with diagnosis and / or treatment.
Risks
Some patients do not like the taste of GlucosePro or be unable to drink it, in which case an alternative glucose solution, Polycal, can be used.
Alternatives
If you have any queries, please contact the requesting clinician.
Contact details for further information
If you have any queries, please ring your local laboratory:
Goole Tel. 03033 304025 Reception 0830-1600 (Mon-Fri)
Grimsby Tel. 03033 302677 Reception 0800-1700 (Mon-Fri)
Scunthorpe Tel. 03033 302641 Reception 0800-1700 (Mon-Fri)
Louth Tel. 01507 600100 Ext 1253 Reception 0830-1630 (Mon-Fri)
Any comments, compliments, concerns or complaints
If you have any other concerns please talk to your nurse, therapist or doctor. Our Patient Advice and Liaison Service (PALS) is available on 03033 306518 (Grimsby, Scunthorpe and Goole). You can also contact [email protected]
As a Trust we value equality of access to our information and services, therefore alternative formats are available on request at [email protected]
Review Information
Date of Issue: May 2024
Review Period: May 2027