Obesity linked to increase in rheumatoid arthritis among women

Researchers at the Mayo Clinic have found that a history of obesity puts women at significant risk of developing rheumatoid arthritis, according to a study published in Arthritis Care & Research.

“We know that fat tissues and cells produce substances that are active in inflammation and immunity,” Eric Matteson, MD, stated in a Mayo Clinic news release. “We know too that obesity is related to many other health problems, such as heart disease and diabetes, and now perhaps to autoimmunity. It adds another reason to reduce and prevent obesity in the general population.”

Matteson and his team examined medical records dating from 1980 to 2007, looking specifically at 813 adult patients with rheumatoid arthritis (RA) and 813 adult patients without, according to the study abstract. The researchers looked at each patient’s height, weight and smoking status. Patient with a BMI over 30 were defined as obese in the study.

Thirty percent of the patients in each group were obese, according to the release, with women making up 68% of the overall cohort.

According to the study results, history of obesity was found to be a significant risk factor for the development of RA, with RA cases increasing by 9.2 per 100,000 women from 1985 to 2007 and obesity accounting for 52% of the increase.

“Obesity is associated with a modest risk for developing RA,” the authors wrote in the abstract. “Given the rapidly increasing prevalence of obesity, this has had a significant impact on RA incidence and accounts for much of the recent increase in incidence of RA.”

Smoking was found to be a substantial risk factor for RA development, according to the release, but its prevalence remained constant over the years studied and thus it was ruled out as an explanation for the increase in RA rates.

Reference:

Crowson CS, Matteson EL, Davis JM, Gabriel SE. Obesity fuels the upsurge in rheumatoid arthritis. Arth Care Res. 2012. doi: 10.1002/acr.21660