Well, well. I have the same thing and hadn't even paid attention to it until I read that. Learn something every day.
My hair is thinning also. I had my thyroid checked too and it came back okay. I have read all sorts of things and I can never find anything that blames diabetes. I sometimes wonder if it is my diet? I have read sugar will do a number on the body. If you find an answer, let me know.
When I was diagnosed in 1978 and began using insulin, just some of my hair fell out (back at the bottom) but grew back right away. At the time I related it to introducing insulin, more than the disease because my hairdresser said he had seen it with other medications. Don’t remember telling a doctor about it, though.