Carrying around extra pounds can increase the risk of developing rheumatoid arthritis – but the relationship between weight and this autoimmune disease actually isn’t as cut and dried as it first appears.
First, it should be acknowledged that as body fat and waist circumference goes up, so does the chance of rheumatoid arthritis. Upwards of two-thirds of people with rheumatoid arthritis are either overweight or obese. There is no getting around the fact that extra pounds are risky when it comes to rheumatoid arthritis development.
This obesity-RA relationship comes with a gender difference; specifically, the link shows stronger in women than in men. So for a woman at risk for rheumatoid arthritis down the road (due to family history, age, and/or smoking), losing weight can reduce the risk of disease development. Overall in the United States, the rates of obesity and rheumatoid arthritis continue to rise – which is certainly a public health concern.
Obesity creates several problems in rheumatoid arthritis:
But this weight issue gets a little more interesting in people who already have rheumatoid arthritis. Being overweight helps in one way: higher weight links to a lower risk of mortality from rheumatoid arthritis. In other words, normal weight people die earlier from RA than those who carry extra pounds. This is known as the obesity paradox, in which being overweight correlates to living longer. Body mass index (BMI) of greater than 30 is the threshold where this benefit emerges in those with rheumatoid arthritis.
So what should patients take away from this? Maintaining a healthy BMI reduces the risk of rheumatoid arthritis. In addition there are benefits for achieving healthy weight in those with active RA, since medications tend to be more effective and the additional risk of osteoarthritis is lessened. Of course there are other health benefits of healthy BMI, such as heart health. Overall, the benefits of achieving a normal BMI continue to outweigh any negatives.
Sources
Linauskas A, Overvad K, Symmons D, et al. Body fat percentage, waist circumference and obesity as risk factors for rheumatoid arthritis – A Danish cohort study. Arth Care Res 2018 July 5 doi: 10.1002/acr.23694.
Dar L, Tiosano S, Watad A, et al. Are obesity and rheumatoid arthritis interrelated? Int J Clin Pract 2018;72(1). doi: 10.1111/ijcp.13045.