I have been diabetic for a good part of 2 decades now (Jeuvenile) and have been a smoker of finer herbals for about as long. Aside from the "munchies" there have been no real adverse side-effects of smoking. Although it is not proven I suspect that some strains of smoke actually serve to lower the blood sugar. I did test this out once upon a time (when I actually gave a shit) and it did lower my sugar by about 20. Whoever posted that Diabetics should not smoke is correct. Smoking restricts the small blood vessels and ironically, diabetes does the same thing so, in essence you are doing a double-whammy by having diabetes and smoking. I am also a smoker, regretfully and have experienced some adverse effects from it but am trying to quit. If smoking Marijuana actually serves to restrict the small blood vessels (and I am not aware of this fact) then I would have to saY that, aside from using a vaporizer, that Diabetics should avoid it altogether. Nuf said!