How does the OGTT define diabetes and prediabetes?
In the OGTT, a person’s blood glucose is measured after a fast and 2 hours after drinking a glucose-rich beverage. Normal blood glucose is below 140 mg/dl 2 hours after the drink. In prediabetes, the 2-hour blood glucose is 140 to 199 mg/dl. If the 2-hour blood glucose rises to 200 mg/dl or above, a person has diabetes.