Taking any form of Steroid if you are diabetic is never a good thing as it makes controlling diabetes B/G levels very much harder due to the inevitable rise in B/G levels. Steroids causes an impact in the body basal metabolism, which makes diabetic patients a susceptible target to that impact increasing or moving the lipid profile and glucose levels to the roof is not regularly control and checked. The short term complications can vary and be very simple(or not) long term complications are a big problem here (macro and micro-vascular complications). Can you use them? maybe… but at the end is your decision. Never do anything without consulting your physician.
Injectable steroids are injected into muscle tissue, not into the veins. They are slowly released from the muscles into the rest of the body, and may be detectable for months after last use. Injectable steroids can be oil-based or water-based. Injectable anabolic steroids which are oil-based have longer half-life than water-based steroids. Both steroid types have much longer half-lives than oral anabolic steroids. And this is proving to be a drawback for injectables as they have high probability of being detected in drug screening since their clearance times tend to be longer than orals. Athletes resolve this problem by using injectable testosterone early in the cycle then switch to orals when approaching the end of the cycle and drug testing is imminent.