Description
Glucose Tolerance Test
(3hr)(F,1,2,3HR)
Sample Type:Plasma
Tests Included:
Evaluation of glucose levels at fasting, 1 hour, 2 hours, and 3 hours after consuming a glucose solution.
Sample Re
quired:
Blood sample
Test T
ime:
Results are typically available on the same day or within a few days.
Test R
ange Values:
Normal values for glucose levels can vary based on the time of measurement and individual circumstances. Generally, for a glucose tolerance test, values above 200 mg/dL at 2 hours indicate impaired glucose tolerance.
What 
is the test?
The Glucose Tolerance Test (GTT) over 3 hours assesses how the body processes glucose at various intervals after ingesting a glucose solution. It’s used to diagnose diabetes, gestational diabetes, and assess insulin resistance.
Test P
rocedure:
The test involves fasting overnight, then drinking a glucose solution. Blood samples are taken at specific intervals to measure how the body processes glucose over three hours.
When to take the test:
This test is often used to diagnose diabetes or assess gestational diabetes during pregnancy. It might also be ordered when there’s suspicion of insulin resistance that’s not captured in a standard 2-hour GTT.
Who should take the test:
Individuals with risk factors for diabetes, gestational diabetes, or those showing symptoms like excessive thirst, frequent urination, or unexplained weight loss might be recommended to take this test.
Precautions for exceptional cas
es (pregnancy, etc.):
Glucose tolerance testing, particularly over 3 hours, is important during pregnancy to screen for gestational diabetes. Pregnant individuals should inform their healthcare provider about their pregnancy status.
Frequently Asked Questions (FAQs) for Glucose Tolerance Test (3hr):
Q1: How is the 3-hour glucose tolerance test different from the standard 2-hour test?
A: The 3-hour test extends the evaluation period to capture more detailed information about glucose metabolism, especially in cases where the standard 2-hour test might not provide a clear diagnosis.
Q2: Can the 3-hour test give different results than the 2-hour test?
A: Yes, the extended test period might provide additional insight, especially in cases of suspected diabetes or gestational diabetes where glucose metabolism might be less predictable.
Q3: Are there specific dietary or activity restrictions during the 3-hour test?
A: Similar to the standard GTT, individuals are usually asked to fast overnight and avoid certain foods or excessive physical activity that might affect glucose levels.
Q4: Can this test determine the severity of diabetes?
A: The test helps diagnose diabetes and assess glucose metabolism but might not specifically determine the severity of the condition.
Q5: What do elevated glucose levels during the 3-hour test indicate?
A: Elevated glucose levels at fasting or during the 1, 2, or 3-hour measurements might suggest impaired glucose tolerance, prediabetes, or diabetes.
*Please note that specific testing protocols and guidelines may vary based on the latest recommendations from health authorities and regulatory agencies. It is essential to consult healthcare professionals and follow local testing guidelines for accurate and appropriate testing.
