Prediabetes 2-hour post-glucose range after an oral glucose tolerance test is:

• A. 100-126 mg/dL
• B. 140-200 mg/dL
• C. 70-99 mg/dL
• D. >200 mg/dL

Answer: (B)

In the oral glucose tolerance test, the 2-hour post-load value after drinking 75 g of glucose is used to classify glucose tolerance. Prediabetes, defined as impaired glucose tolerance, corresponds to a 2-hour glucose level around 140 to just under 200 mg/dL. This is why a range like 140–200 mg/dL is considered the prediabetes range on the 2-hour test. If the value reaches 200 mg/dL or higher, that indicates diabetes, while a value below 140 mg/dL is considered normal. The 70–99 mg/dL and 100–126 mg/dL ranges refer to fasting glucose categories, not the 2-hour post-load measurement.