I did some more research on the connection between rheumatoid arthritis (RA) and ethnic background.
One interesting study conducted by the University of Texas examined the information of 777 rheumatoid arthritis patients. This included 432 Hispanic, 272 non-Hispanic whites (NHW), 53 African American and 20 Asian. Of these, 498 were women. This study found that Hispanics had significantly more tender joints, swollen joints, and more frequent rheumatoid factor positivity than NHW. They also found that African Americans had a higher onset age and less frequent subcutaneous nodules that NHW. They concluded that there is an ethnic variation in the clinical expression of rheumatoid arthritis.
Another study looked at the outcomes of 5685 rheumatoid arthritis patients from the Arthritis, Rheumatism, and Aging Medical Information System (ARAMIS) database. This study compared levels of function, pain and overall health status between Caucasian, Hispanic and African Americans.
The results of this study showed that the Caucasian patients had the best scores for all three measurement parameters among the three ethnic groups, while Hispanics reported the worst scores on all three parameters. The researchers did note, however, that the Caucasian patients were better educated and on average, were older. They also indicated that there were other potential factors that were not included in the analysis such as gender, rheumatoid factor status and level of treatments received.
A third study was from Canada that was a retrospective chart analysis of Canadian aboriginals, Finnish Canadians, Italian Canadians and other Caucasian Canadians. Their findings showed that Canadian aboriginals developed RA at an earlier age than the other groups and they were more likely to have a family history of RA. They also found, as other studies have found, that women were more likely to develop rheumatoid arthritis than men.
In addition, the drugs used to treat RA appeared to have similar effects regardless of the ethnic background, although the Italian and other Caucasian groups were more likely to report reactive dermatitis.