In the comments of a recent post, I and a couple other people mentioned Type II, or insulin independent, diabetes. You might assume that the existence of a type II means there must be a type I and, well, you’d be right.
The difference between type I and type II is fairly straightforward: type II diabetes is characterized by a loss of sensitivity to the hormone insulin, while people with Type I diabetes don’t make any insulin to begin with. The reason for this lack of insulin (in people with Type I) is, broadly speaking, that the cells that make it have been destroyed by their own immune system.
The genetic basis of type I diabetes is murky, but it’s known that there are risk factors in genes involved in immunity and the production of insulin, as one might expect. But there’s also evidence of a strong environmental role (these points are essentially copied from the abstract of this paper):
1. a pairwise concordance of type 1 diabetes of