As a diabetic I can say that is can be extremely deadly. Actually that's what keeps me so healthy. I've learned all the terrible things that can happen. Not just kill you but first do all kinds if terrible things to each organ in your body.
And limbs as well. My friend went in to have her right big toe removed because of diabetes and came out of recovery with her leg gone from the knee down. Surprise! She is learning to drive with a prosthetic right leg and foot.