What Are the Complications of Rheumatoid Arthritis?

Rheumatoid arthritis is probably most widely known for attacking the joints, leaving joint-related disability as its hallmark. However, many people may not realize that RA doesn't just affect the joints. It is an inflammatory autoimmune disease that also causes complications in many organ systems and tissues throughout the body, including the heart, blood vessels, lungs, bones, eyes, skin, kidneys, salivary glands and nerve tissue.

According to the Mayo Clinic, approximately 40 percent of people with RA have signs and symptoms that don't involve the joints.

Of all the non-joint-related complications of RA, cardiovascular disease is the most serious. It is the leading cause of death in both men and women in the U.S., and people with RA have twice the risk of most cardiovascular-related problems compared with the general population, including heart attack, strokes and atherosclerosis -- hardening of the arteries caused by the buildup of plaque on the inner walls of the blood vessels. The risk of heart failure is also increased.

[See: How to Practice Yoga When You Have Arthritis or Another Chronic Condition.]

The cardiovascular disease that develops in people with RA is different from the disease that occurs in people who do not have RA, probably because it is the result of the systemic inflammation that RA unleashes. It occurs earlier, is more severe and the outlook is worse following an event such as a heart attack or stroke.

The risk of osteoporosis -- bone loss and fracture -- is also increased in people with RA, especially in the areas immediately surrounding affected joints. According to the Osteoporosis and Related Bone Diseases National Resource Center of the National Institutes of Health, there are many reasons for this.

The corticosteroid medications that are often prescribed to treat RA can cause substantial bone loss. Pain and loss of joint function can also lead to inactivity, which increases the risk of osteoporosis even more. But RA itself may cause osteoporosis.

Inflammation and scarring of the lungs -- called interstitial lung disease -- is also a hazard of RA. Over time, scarring can make it difficult to breathe and some individuals may need lung transplants.

The Arthritis Foundation lists several risk factors for interstitial lung disease, including smoking, higher levels of RA disease activity, older age at initial RA diagnosis -- especially after age 60 -- and treatment with disease-modifying antirheumatic drugs like methotrexate.

Male gender also increases the risk of lung disease. "We are not sure why that is," says Dr. Kevin Deane, a rheumatologist and associate professor of medicine at the University of Colorado in Denver, "but it could be in part because men may smoke more cigarettes than women."

Rheumatoid arthritis can also lead to myriad additional complications. According to the Mayo Clinic, these include:

-- Rheumatoid nodules. These are firm lumps of tissue that can occur throughout the body, including the lungs, although they are most often found around pressure points, such as the elbows.

-- Dry eyes and mouth. Individuals with RA are much more likely to develop Sjogren's syndrome, a disorder that is characterized by dry eyes and decreased saliva production.

-- Infections. RA medications and RA itself can impair immune system functioning, which can increase the incidence of infection.

-- Abnormal body composition. Individuals with RA often have a higher proportion of fat compared to lean mass, even in people who have a normal body mass index.

-- Carpal tunnel syndrome. When RA affects the wrist joints, the inflammation can compress the median nerve in the wrist.

-- Lymphoma. RA increases the risk of developing lymphoma, a group of blood cancers that arise in the lymph system.

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Sleep difficulties can also occur in individuals with RA, and a handful of studies indicate that people with RA may have an increased risk of obstructive sleep apnea, which is characterized by multiple pauses in breathing during sleep that can last from seconds to more than a minute.

"There does seem to be a higher prevalence of obstructive sleep apnea in RA patients," says Dr. Clete Kushida, a neurologist and medical director of the Stanford Sleep Medicine Center.

A sleep study is necessary to determine if insomnia is caused by a sleep disorder. "Pain can also disrupt sleep and can lead to daytime sleepiness," Kushida says.

Deane also considers the high cost of RA to be a further complication. "[The costs of] health care provider visits, medications and work loss are important," he says.

"To reduce complications, the main goal is to diagnose RA early, before joint damage can develop, and then control arthritis with the modern medicines that are available," Deane says. "Good control of joint disease also seems to help reduce other complications like cardiovascular disease that may be a direct result of inflammation."

Additional measures may help prevent complications, Deane advises, including getting appropriate vaccines and watching for infections, monitoring and treating bone health, stopping smoking and maintaining optimal body weight because obesity is a risk factor for poor disease control.

Ultimately, perhaps the best way to avoid the complications of RA is to prevent them from developing.

"On the near horizon, an exciting issue in RA is that we and others are working to try to prevent the arthritis of RA from ever developing," says Deane, who is currently an investigator in a prevention study called StopRA.

The study is enrolling people who have not developed RA but have high blood levels of antibodies to cyclic citrullinated protein, or anti-CCP, a risk marker for RA. Study participants are treated with the drug hydroxychloroquine to determine if treatment in the early, pre-clinical phase of the disease can delay or prevent the development of RA.

[See: 9 Ways to Boost Your Immune System.]

The StopRA study is based on a recently concluded European prevention trial called PRAIRI, which showed that a single dose of the drug rituximab can delay the onset of RA.

"The results of [the StopRA] trial and others should be out in the next few years and may change the way RA is treated," Deane says.

Maureen Donohue is a freelance Health reporter at U.S. News. A medical writer, editor and journalist since 1991, Maureen has written for both physicians and consumers covering a wide a variety of medical topics. Maureen's work has been published in several prestigious, peer-reviewed medical journals as well as on consumer-based websites. She has been a writer for the Stanford School of Medicine, Healthline Media, the International Medical News Group, the UC Davis Cancer Center, the Arizona Heart Institute, MedExperts International and the Sutter Institute for Medical Research. You can connect with Maureen on LinkedIn or email her at emelldee@icloud.com.