If a FPG doesn’t catch diabetes, this test may — as it’s known to be more sensitive. Like the FPG test, the patient must fast for eight hours or more before taking the OGT test. The patient’s blood sugar levels are then measured just before and two hours after drinking a beverage that contains sugar. The patient would be diagnosed with prediabetes if their blood sugar was between 140 and 199 mg/dL two hours after drinking the beverage, and diagnosed with diabetes if their blood sugar was above 200 mg/dL.
