Does your fasting blood glucose have to be in a specific range for a doctor to order a gtt ?when will a doctor order one?

Various doctors: Order gtt's for various indications. Check w/your doctor about their views and intentions. One indication that should never be used for a GTT is a concern about "reactive hypoglycemia". The GTT is not and never will be a valid test for hypoglycemia, in fact reactive hypoglycemia doesn't exist in the absence of cancer, severe liver or kidney disease, prior GI surgery, someone receiving diabetes med.