Calm down, deep breaths...my PPID/IR mare has frequently high glucose, and she's fine. Yes, your horse is still IR -- the "diabetes" label is just another way to classify the IR. It is all academic exercise for your brain and nothing changes the treatment or management. Keep doing what youre doing if Po is doing well.
My mare's hyperglycemia is intermittent. Her insulin is often concurrently high. Technically the high glucose defines her as a Type II diabetes mellitus (high glucose & high insulin). It doesn't mean anything unless she is outwardly sick, and she is not. She is still Insulin Resistant and has PPID as the core of her problem, and that is what I treat and manage. Her insulin levels are at present well-controlled with pergolide. I make note of my mare's high glucose numbers and as long as she's acting fine, that's all I can and will do for now. It is the sustained high insulin that brings on the dreaded IR symptoms (tender feet, etc).
As I understand, hyperglycemia is a way of differentiating between IR of PPID and IR as a primary malady (the latter does not usually have hyperglycemia concurrent with hyperinsulinemia).
Everything is ok, Coral! You've just reached a new level of understanding your horse's condition. Nothing really will change, except you'll have something new to talk about at dinner parties ;)
Kerry in NY