A GTT test or glucose tolerate test is a test that measures how well your body handles glucose. This test is used to detect if there is a problem such as diabetes type 2 or gestational diabetes which is only found in pregnant women. There is the oral test and the intravenous test for GTT test. The oral test, known as OGTT test, is more common because it renders results for most people that are accurate. When a person gets the intravenous test, this is often referred to as the fasting blood sugar test.
Who Needs a GTT Test?
Those who need a GTT test are people who are expected to have issues with their blood sugar levels and pregnant women. Pregnant women are recommended to get this test when they are between 24 and 28 weeks pregnant. Women who tend to develop gestational diabetes often have some common risk factors, which include:
- Women whose body mass index is above 30.
- Women who have given birth to large babies over 9 pounds before.
- Women who have had gestational diabetes inprevious pregnancy.
- Women who have family members that have diabetes.
- Women who have family origin factors for diabetes, such as being South Asian, African-Caribbean descent or Middle Eastern.
For people who have blood sugar issues, the GTT test is often given to know what their glucose levels are and to conclude whether they have diabetes or are close to develop diabetes.
What Are the Preparations Before GTT Test?
A GTT test does not require significant preparations, but there are a few things to keep in mind:
- Most of the times your test will be scheduled for the morning.
- At least 3 days before the test, keep to your regular diet, so you will get results that are typical for your lifestyle.
- Be sure that you are healthy and well for at least 2 weeks before the test.
- 8 to 10 hours before the test, avoid eating or drinking. However, you can have sips of water if thirsty.
- Have a list of current medications that you are taking.
- Do not smoke one hour before the test or during the test.
- Let the doctor know if you have any allergies.
How Is GTT Test Performed?
To start the GTT test, a sample of blood is taken from the patient. After this sample is taken, the person is asked to drink an oral glucose solution. This solution puts a certain amount of sugar into the body, and then blood tests are performed 30 to 60 minutes after drinking the solution. The entire time of the test can take up to 3 hours, depending on what the doctor wants to measure. In high risk patients, the blood is often taken every hour after drinking the solution for the next 3 hours.
The intravenous test involves injecting glucose into the blood stream and pulling blood every few minutes to check for imbalances, though this is not the test that is often used by doctors.
How Are the Results of GTT Test Evaluated?
The results of the GTT testwill explain what issues a person may have by analyzing their glucose blood levels. These results are:
- Normal. When the test shows a blood glucose level that is at or below 140 after a two-hour window, then the person is said to have a normal result.
- Impaired Glucose Tolerance. This is found when the fasting level glucose measures at 126 mg/dl or the glucose blood level is above 140 mg/dl and lower than 199 mg/dlduring a two-hour window. This result is often referred to as pre-diabetes.
- Diabetes. In order to confirm diabetes, the GTT test has to be done on two different days. If the result of fasting level is above 126 mg/dl, while the two-hour window result is above 200 mg/dl, it means you have diabetes.
- Gestational Diabetes. In pregnant women, the fasting level that is over 92 mg/dl or the two-hour window level is above 153 mg/dl shows that gestational diabetes is something that she needs to be aware of and she need to adjustthe diet to help avoid it.
What Are the Treatments for Positive GTT Test?
If you have had positive GTT test, your doctor will recommend some treatments for you.For some people, insulin may be prescribed as a way to manage the glucose levels in the body. Beside, you may find that with proper diet and exercise, you can get glucose levels in the control. This is why many doctors recommend the person go to a nutritionist.