Rise in RA Linked to Obesity

Obesity puts a strain on your body. As rates of obesity continue to grow among Americans, so do rates of obesity-related conditions like diabetes. Is obesity also to blame for the rise in rheumatoid arthritis?

Women who are obese may have an increased risk of rheumatoid arthritis.

gnored as a risk factor for rheumatoid arthritis. In recent years, rates of both obesity and rheumatoid arthritis have been on the rise.

Dr. Gabriel and colleagues wanted to see if the obesity epidemic could explain for the recent rise in rheumatoid arthritis.

They found that obesity was associated with a modest risk of rheumatoid arthritis.

"We know that fat tissues and cells produce substances that are active in inflammation and immunity. We know too that obesity is related to many other health problems such as heart disease and diabetes, and now perhaps to autoimmunity," says Eric L. Matteson, M.D., M.P.H., also of Mayo Clinic and one of the study's co-authors.

"It adds another reason to reduce and prevent obesity in the general population," he says.

Rheumatoid arthritis is an autoimmune disease, which means that the body's immune system mistakenly attacks healthy tissue. It causes painful inflammation around the joints and other tissues. The inflammation can even spread to other organs.

In their recent study, Dr. Gabriel and colleagues recorded an increase in cases of rheumatoid arthritis among women. Between 1985 and 2007, there were 9.2 new cases of rheumatoid arthritis per 100,000 women.

Obesity was linked to 52 percent of this increase.

Smoking was also linked to rheumatoid arthritis risk. However, smoking habits did not change much during the study period, ruling it out as the cause of increased rates of rheumatoid arthritis.

Scientists are still unclear about how obesity is linked to autoimmune diseases, explains Dr. Matteson. More research is needed to figure out how obesity may lead to rheumatoid arthritis.

For their study, the researchers looked at medical records from the Rochester Epidemiology Project, and studied 813 rheumatoid arthritis patients and 813 otherwise healthy adults.

The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases.

The research was published April 18 in Arthritis Care & Research.