AM I REQUIRED TO FAST FOR THIS LAB TEST?
Yes. You must fast at least eight (8) hours prior to having your specimen collected.
WHAT IS THE PRICE OF A GLUCOSE TOLERANCE LAB TEST?
*Price may vary by location – contact your local ANY LAB TEST NOW
The Glucose Tolerance Test is a test that checks how the body metabolizes sugar. The oral glucose tolerance test is where you are asked to drink a cup of glucose (75 grams). Your blood will be collected before you drink the glucose, and every 30 to 60 minutes after drinking the solution. The test usually takes up to 3 hours to complete.
The test is done to diagnose hypoglycemia (low blood sugar), prediabetes, diabetes, gestational diabetes in pregnant women between 24 to 28 weeks of pregnancy, or metabolic disorder (i.e. Cushing’s Syndrome).
WHY DO I NEED A GLUCOSE TOLERANCE LAB TEST?
This test is a confirmatory test for diabetes. If you have a family history of diabetes, or recent elevated blood glucose or diabetic signs and/or symptoms, such as increased thirst, increased frequency of urination, slow healing wounds, numbness of your hands and/or feet and increased irritability or fatigue, you might consider this test.
This is also a standard test for pregnant women between 24 – 28 weeks of gestation, and for individuals who are at high risk of gestational diabetes.
OTHER RELEVANT LAB TESTS:
You might also consider a Hemoglobin A1c, which measures your blood sugar over a three (3) month period. Insulin and C-peptide levels can also be ordered to measure and evaluate insulin production.
75-gram oral glucose tolerance test: Normal Blood Values
|Normal||60 – 100 mg/dL|
|1 Hour||< 200 mg/dL|
|2 Hours||< 140 mg/dL|
50-gram oral glucose tolerance test: Normal Blood Values
|1 Hour||< or equal to 140 mg/dL|
100-gram oral glucose tolerance test: Normal Blood Values
|Fasting||< 95 mg/dL|
|1 Hour||< 180 mg/dL|
|2 Hour||< 155 mg/dL|
|3 Hour||< 140 mg/dL|
High Results Indicate:
High levels of the Glucose Tolerance Test may indicate prediabetes, diabetes, gestational diabetes, or metabolic disorders (i.e. Cushing Syndrome, hyperthyroidism or acute stress).
Low Results Indicate:
Low levels of the Glucose Tolerance Test may indicate adrenal insufficiency, hypothyroidism or insulin overdose.
WHAT TYPE OF PHYSICIAN SHOULD I SEE IF MY TEST RESULTS ARE ABNORMAL OR OUT OF RANGE?
You should see your primary care physician, endocrinologist or OB/GYN for further evaluation.