Good link by brainiac above.
First of all let us talk about Type 1 ( lack of insulin).
in the 1920's insulin was first used to treat "diabetes" and before that, you either died or live on a ridiculously low carbohydrate diet and Then you died......whichever way, one didn't last long.
Insulin in 1922 changed all that.
Type I affected all aspects of the body,,heart, kidneys , brain....etc and as a medical student in the 50's one was told:
"Know diabetes and you know medicine"
Type 2 ....sort of slid into prominence in the 50's and was known as "Early onset diabetes".....and that grew into prominence with people living longer, a more affluent lifestyle and the discovery of tablets taken by mouth to control the disease and is indeed a "bigger deal" that Type 1 diabetes.
This is a potted version of diabetes as it is always difficult to know how high to pitch one's answers in AB, so that one doesn't insult one's intelligence.
When one talks of diabetes one always assumes that diabetes mellitus is the topic, but there is another form of diabetes,diabetes insipidus which is extremely rare and due to problems of the base of the brain.
I have never seen such a case.