It can happen to people who are insulin resistant even before they get the diabetic or pre-diabetic diagnosis. They are heading toward diabetic and already being damaged and just don't know it.

If doctors would request an fasting insulin assay in addition to the standard blood tests a person could tell if they were heading for trouble long before it shows up in fasting blood glucose test or HbA1c. The range for insulin is something like 2-20 which is crazy. Metabolically healthy people should be in single digits and according to some doctors 5 or less ideal.