How much of a risk is 5mg prednisone?

Well, I don't know what you mean by long term. You don't want to stay on Pred permanently and taking Pred to manage blood sugar problems (which is probably being caused by the Pred) doesn't make much sense. But you have been on it four months...which doesn't seem terrible. You do need another plan beyond steroids. Google the side effects of Prednisone if you need motivation to try for an alternative.

Were you doing 5mg/day before you went to 5mg/every-other-day? How long had you been doing the 5mg/day? Can you give us your full history of how much you've taken over the four months?

Once you get to 5mg, you're below what your adrenal glands normally produce every day. But since you've been on higher doses (I'm assuming) for a few months, your adrenal glands may have atrophied and need time to come back.

If you're struggling with just going from 5mg/day to 5mg/every other day, you can get prednisone in 1mg sized pills and then go to 4mg/day, then 3mg/day, then 2mg/day, then 1mg/day, etc, every few days. That should be slow enough to give your adrenal glands time to wake up and get to work.

I'm aware of all the issues mentioned; that is why I brought up the topic. I am just interested in knowing how it may affect me after taken for several months at such a low dose.