A link between stress and rheumatoid arthritis (RA) is commonly acknowledged. However, scientists continue to explore the connection between the nervous and immune systems and the effect on RA onset and progression. People with RA commonly report experiencing physical or emotional stress when first diagnosed with an autoimmune disorder like RA. However in a 2010 editorial in Arthritis Research & Therapy, Daniel Clauw, MD, a professor of anesthesiology at the University of Michigan (who has expertise in rheumatology and pain), commented on a review of 16 studies on the stress-arthritis link. In his editorial, Dr. Clauw highlighted the verified link in animal models and the difficulty in proving a similar linear relationship in humans.
“The reason it’s difficult is that it is hard to measure stress, and we know that not all types of stress are equally capable of affecting different individuals in the same way,” explains Dr. Clauw.
But evidence of a connection remains an important focus among researchers. In the same editorial, Dr. Clauw referenced a study that found Vietnam combat veterans with post-traumatic stress disorder (PTSD) had an almost 17 percent higher risk for autoimmune diseases compared to those without PTSD. A 2009 study in Psychosomatic Medicine showed that people with two or more traumatic events in their childhood had a 100 percent higher risk for rheumatic diseases compared with people who didn’t suffer childhood trauma.
How Stress Affects the Immune System
Showing a correlation between stress and the inflammatory chemicals associated with RA has been complicated. “We know that stress affects the sympathetic nerve system and cortisol levels, explains Theodore R. Fields MD, an attending physician in rheumatology at New York’s Hospital for Special Surgery. “But in terms of being able to show how that’s related to specific inflammatory chemicals of RA, we need more data.”
It’s believed that stress reduces the immune system’s ability to function properly. Researchers are trying to better understand the role of proinflammatory cytokines like interleukin-6 (IL-6) released during times of stress. Alex Zautra, a professor in the Department of Psychology at Arizona State University, co-authored a commentary published in the October 2013 issue of Nature Reviews Rheumatology about a July 2013 Dutch study on the effect of stress on joints. In the study, researchers measured levels of cortisol and inflammatory markers like IL-6, IL-8, interferon and tumor necrosis factor.
They found that daily stressors (for example, long appointment wait times or losing something valuable) predicted increased fatigue for patients the next month, and worrying predicted increased patient reports of pain, swollen joints and disease activity the following month. But inflammatory markers and cortisol levels did not appear to change because of stress.
“Different biopsychosocial pathways of disease progression need to be charted,” Zautra and his co-author wrote.
Zautra does believe there’s a link between RA and stress. A 2008 study he co-authored, which was published in Brain, Behavior, and Immunity, showed that higher chronic interpersonal stress did predict increased levels of IL-6 and inhibit the ability of corticosteroids to stop IL-6 production. “There is evidence that it might speed up the immune dysfunction or delay recovery. That’s all possible,” he explains.
Zautra’s research also shows that for RA patients, lack of good relations during times of stress is most associated with worsening illness, and women with better spousal relationships don’t see an increase in disease activity following an episode of interpersonal stress. “The fundamental value of others is in the social connection. To not be alone is the key. To share joy and heartache, those aspects of relations are what matters,” Zautra explains.
Can Stress Relievers Alleviate RA Symptoms?
Researchers are also working to understand how modifying stress affects RA on a biological level.
In a review published online on Sep. 10, 2013, in the Journal of Evidence-Based Complementary & Alternative Medicine, author Manoj Sharma PhD, a professor at the University of Cincinnati found yoga to be a promising modality for arthritis. Of nine studies done between 2010 and June 2013, six showed positive changes in psychological and physiological outcomes related to arthritis, including pain. “It relieves stress because your mind is not dwelling on things that are causing you anxiety and stress,” Sharma explains, adding that this form of low-impact exercise also strengthens muscles and adds to the flexibility of joints.
Zautra’s research has also shown that mindfulness meditation, which focuses on acceptance and cognitive behavioral therapy, which works to combat negative thought patterns, can help people manage their RA pain. ”The mind is in the brain and the brain is in the body, so, if we change the way we think about something, it will have a physiological effect,” Zautra says.
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