My mother and grandfather do. I think they have Type Two... could be Type One. I probably will get it eventually, considering which half of the family I get my genes from and whatever...
Life has pretty much just moved on after they were diagnosed though. My parents don't keep as much "snack food" around the house, and I try to be nice and not say things like "this is sooo good" or "I've been craving this" when I eat something they can't eat.