Glucose Tolerance Test: Information for Patients
Introduction
A glucose tolerance test has been requested by your doctor, which involves assessing how your body deals with an intake of glucose. The purpose of the test is to see if you have sugar diabetes.
The procedure involves taking a blood sample from your arm when you arrive for your appointment, which is taken to the laboratory where the blood sugar level is measured. A finger-prick sample will also be taken and tested on a meter in the clinic. This cannot be used for diagnosis but will identify patients with high blood levels of glucose before starting the test. These patients may not require the second part of the test and will be sent home once the meter result has been confirmed.
Most patients will be asked to drink a sugary liquid. The drink contains (75g) 2 ½ ounces of a sugary drink, dissolved in water. You should drink this all within five minutes and you will then be asked to sit quietly for two hours. You must not smoke during this test. After the two hours you will have a second blood test in which the blood sugar level will be measured again. Once this second blood test has been performed you may go home.
What are the benefits of me having the procedure?
Your doctor has referred you for a glucose tolerance test as you may have symptoms of diabetes mellitus. The results of the glucose tolerance test will help us to diagnose or rule out diabetes mellitus.
What are the risks, consequences and alternatives associated with having the procedure?
A few patients may suffer headaches after drinking the sugary drink, rarely some people may feel sick or actually be sick. You should contact one of the numbers below to let them know if you are one of the few patients who have a reaction to orange flavourings or colourings to enable a different sugary drink to be provided for you. If you are concerned about any of these risks, or have any further queries, please speak to your Doctor. The procedure will only be carried out with your consent.
Heartlands Patients Diabetes Centre 0121 424 0234 Solihull Patients Biochemistry Lab 0121 424 5527 Good Hope Hospital Biochemistry Lab 0121 424 7250
Will I be asked to a pre-admission appointment – what will happen?
The procedure is carried out as an out-patient procedure and does not require admission to hospital, therefore, no pre-admission appointment is required.
Getting ready for the procedure
After 11.00pm on the night before the test you must not eat or drink anything other than water. Drink enough fluid to avoid feeling thirsty. Do not eat breakfast on the day of the test. You should expect to be in the clinic for approximately 3 hours. Smoking is not allowed. We suggest you bring something to read to pass the time.
For some procedures some patients will be required to sign a consent form, but for this test this is not necessary. By drinking the sugary drink and allowing us to obtain a blood sample from you, you are giving your consent. You will have the opportunity to discuss the procedure with the health professional responsible for carrying out the glucose tolerance test at the time of your appointment.
What should I expect after the procedure?
There should be no pain following the test. The sugary drink makes some people feel a little sick but this should pass within an hour or so. You can eat and drink normally when you leave the hospital but must not eat between the 1st and 2nd blood sample been taken. You should expect to return to what you would normally be doing on that day when you leave the clinic.
What happens when I leave the hospital?
You will not need any further time off from work/school and should be able to return to what you would normally be doing on that day. The results of the test will be sent to your doctor and he will let you know whether you need any follow up appointments.
Further Information
If you cannot attend, or do not understand what you have to do, please telephone one of the following numbers between 9.00 am – 4.00pm, Monday to Friday.
Heartlands Patients Diabetes Centre 0121 424 0234 Solihull Patients Biochemistry Lab 0121 424 5527 Good Hope Hospital Biochemistry Lab 0121 424 7250
Cross relate to QPulse document BI.L002 v6 active 31/07/12, review 31/07/14