Found this on the web, a couple years old at this point:
Interestingly to me, as a kid I suffered from migraines... right up until my last year in junior high when I was diagnosed with T1 diabetes. Since then I've had some headaches but nothing like the semi-regular migraines I suffered with before then.
I was taking a daily migraine medicine for about 2 years before I was diagnosed with type two diabetes (I had suffered from migraines for at least 5 years before seeking treatment). When I started diabetes medicine I decided to try cutting out the migraine medicine (I did not want to take any more pills) and to my surprise the headaches were mostly gone. I still have headaches here and there, but the frequency and severity are much less than they used to be. I don't know if this could be related to my diabetes, but this is really interesting. It would be nice to know that diabetes can have some positive side affects!