Being obese or overweight can increase the risk of a host of health problems — diabetes, heart disease and stroke, for instance. Packing too many pounds may also raise the risk of rheumatoid arthritis.
A recent study found that women who were overweight or obese faced an increased risk of rheumatoid arthritis, a chronic condition marked by joint inflammation and pain.
This study was conducted by Bing Lu, MD, of Brigham & Women's Hospital and Harvard Medical School in Boston, and colleagues.
The study authors analyzed two groups of female nurses from previous studies: one group of 109,896 from the Nurses' Health Study and another group of 108,727 from Nurses' Health Study II.
The researchers reported that the women in both groups took surveys every two years. The Nurses' Health Study was conducted between 1976 and 2008, and the Nurses' Health Study II lasted from 1989 to 2009.
The surveys asked questions about general health, lifestyle and body mass index (BMI) — a weight-to-height ratio used to determine if someone is a healthy weight. Between both surveyed groups, the study authors noted 1,181 cases of rheumatoid arthritis.
Although the researchers found an overall increased risk of rheumatoid arthritis among the overweight and obese women (with a BMI of 25 or higher), the most pronounced risk was among younger obese women. Women who were obese at age 18 were 35 percent more likely to develop rheumatoid arthritis than the other participants.
Those younger women were about 50 percent more likely to develop rheumatoid arthritis, the study authors noted.
The study authors also reported that women who were obese for 10 years were 37 percent more likely to develop arthritis at a younger age.
The researchers concluded that, in general, rheumatoid arthritis risk increased only modestly in obese women, but the more acute risk was in women who were obese at younger ages.
"Our study implicates being overweight or obese throughout adult life as a risk factor in the development of [rheumatoid arthritis] for women diagnosed with [it] at age 55 years or younger," they wrote.
BMI accounts for overall weight but does not factor in lean muscle weight, the study authors noted. Because people tend to lose lean muscle as they age, the study might not have produced accurate information about rheumatoid arthritis in older women.
The study authors noted the need for further research on this topic to determine the effect of diet — not just BMI — on arthritis in women.
BMJ published this study online July 23.
The National Institutes of Health funded the research. One study author received funding from a Canadian Institute of Health Research Fellowship Award.