Hi - I am not medically qualified but I have much experience of diabetes and prolonged use of steroids which I was taking to control an inflammatory bowel disease (I had Ulcerative Colitis). In fact, the high dose and long use of them actually caused my diabetes.
Like you, I experienced very high levels while taking them. When I was first diagnosed, I used Novomix twice a day. However, in an effort to better control my levels I was changed to Lantus in the evening and Novorapid with meals. To illustrate the change to my levels, whilst I was taking Prednisolone I used 18-20 units of Lantus at night and between 16-20 units of Novorapid with meals, depending on what I was eating. Since coming off steroids I take 14 units of Lantus at night and 8 units of Novorapid with meals.
I was told to tweak my units of Novorapid by 2 units at a time until I achieved reasonable levels. I don't know if your prescriber has ever mentioned this to you but that is the advice I was given by my diabetic specialised nurse, my GP (who is a specialist diabetes GP) and the gastroenterologist who was treating me with the steroids.
I hope this helps. Good luck and I hope the steroids help control your inflammatory problems. If you haven't had them before, be warned they make you hungry .... and you need lots of willpower!
Jackie