This was research presented to the World Congress on Osteoporosis, Osteoarthritis, and Musculoskeletal Disease. This was looking at middle age woman in Britain.
I can tell you that individuals carrying a lot of excess weight wear down their lower joint easier because take a lot of the stress of carrying that extra weight.
I also remember seeing work that showed us that belly size can be a factor as well BMI. That being said, if the individuals with knee osteoarthritis and knee pain are very over weight, I can see the correlation. Being over-weight, of course, has numerous health complicates.