The study that is being cited is a study in mice that had a gene removed. To extend its findings to humans is very far fetched.
They are suggesting that mice with high blood sugars but few insulin receptors in their brains outlived mice with normal blood sugars and insulin receptors in their brains.
We have no idea what the effect of removing insulin receptors from the brain might be on the function of the cortex, which is the part of the brain that mice have very little of, and you use for thought.
Looking at humans we can say conclusively that people with high blood sugars do NOT outlive people with lower blood sugars for a host of reasons.
The way in which the press reports rodent studies without ever mentioning that very few findings in mice relative to diabetes ever translate to humans, is pathetic.
Now doctors will use this as yet another reason to deny people with Type 2 the insulin they need to regain normal blood sugars and prevent severe complications.