Which criterion is used in the oral glucose tolerance test for diagnosing diabetes?

Which criterion is used in the oral glucose tolerance test for diagnosing diabetes?

• A. Fasting glucose >126 mg/dL
• B. 2 hour plasma glucose >200 mg/dL
• C. A1c >6.5%
• D. Random glucose >200 mg/dL

Answer: (B)

In the oral glucose tolerance test, you look at how the body handles a glucose load by measuring the glucose level two hours after drinking a fixed amount of glucose. A 2-hour plasma glucose level of 200 mg/dL or higher is diagnostic for diabetes with this test because it shows the body's tissues aren’t clearing glucose efficiently after the load. The other numbers come from different tests: fasting glucose uses a 126 mg/dL threshold, A1c uses 6.5% or higher, and a random glucose of 200 mg/dL with symptoms is diagnostic in the appropriate clinical context. But for the OGTT, the key criterion is the 2-hour value at or above 200 mg/dL.

In the oral glucose tolerance test, you look at how the body handles a glucose load by measuring the glucose level two hours after drinking a fixed amount of glucose. A 2-hour plasma glucose level of 200 mg/dL or higher is diagnostic for diabetes with this test because it shows the body's tissues aren’t clearing glucose efficiently after the load. The other numbers come from different tests: fasting glucose uses a 126 mg/dL threshold, A1c uses 6.5% or higher, and a random glucose of 200 mg/dL with symptoms is diagnostic in the appropriate clinical context. But for the OGTT, the key criterion is the 2-hour value at or above 200 mg/dL.