In the UK, you can fly with Type 1 Diabetes controlled by Insulin on a
National PPL (NPPL) It is restricted to UK airspace, but you can fly solo or
with a Pilot in the right seat rated on the type. This is based on the
UK driving licence. Other UK states are getting their licences together
on the same basis. The person who signs the Medical Certificate is your
own GP, based on the fact that it is he who knows your health best.
It is a gift from heaven and put lots of us back in the sky who were otherwise grounded. A pretty enlightened CAA if you ask me.
How do I know all this.?? I am one of those fortunate people.
Check the CAA website for more info.