Hi, this is a great forum for finding out everything you never wanted to know about the nasty drugs for PMR. I am concerned for you when reading your post that your Rheumatologist has had you taking 10 to 15mg Prednisone since April when you have diabetes and that you have gone from diet controlled diabetes to needing insulin. And even more concerned that you take it 'when you feel like it' Sounds to me like you need a second opinion. There are lots of great links on this site to help you understand how Prednisone works, a lot of us have had problems with our medical management and have had to become experts on our own disease and how we should be managed.