“The A1C test measures your average blood glucose for the past 2 to 3 months. The advantages of being diagnosed this way are that you don’t have to fast or drink anything.  Diabetes is diagnosed at an A1C of greater than or equal to 6.5%.  Before people develop type 2 diabetes, they almost always have “prediabetes” — blood glucose levels that are higher than normal but not yet high enough to be diagnosed as diabetes.”

American Diabetes Association