I firmly believe that is is extremely common but for lesser cases it is brushed off as something else. I believe that my mom had it and maybe my dad too. It's the inflammatory thing, and it can translate to other inflammatory types of illnesses.

My mom had type 2 diabetes and my dad likely would have too but he was very physically active in his work. Someday maybe genetic mapping or testing will let us know all of the connections or relevance of these conditions.