When people hear the general term arthritis, they typically think of an older person with joint pain as in osteoarthritis – common wear and tear on the joints. But this term can miss the mark when describing the systemic impact of autoimmune rheumatoid disease on the entire body. One of the first symptoms that doctors often examine for establishing a diagnosis of RA is bone erosion – typically in the fingers. But as an autoimmune disease, RA can impact much more than the bones as it can damage a variety of soft tissues including the eyes (iritis), lungs (fibrosis), heart, blood vessels (vasculitis), nerves (carpal tunnel), and skin (nodules, ulcers), and connective tissue (cartilage, tendons, ligaments) (see https://rheumatoidarthritis.net/symptoms/). Often-times, the soft tissue damage occurs long before bone erosion is visible or even before an official RA diagnosis comes.
Besides bone erosion, RA can impact other parts of the joint including the surrounding connective soft tissues comprised of tendons, ligaments, and cartilage. Chronic tenosynovitis, inflammation of the sheath of a tendon, is common in rheumatoid arthritis and can result in the permanent damage and tearing of the involved tendons. Such tendon problems caused by RA are well known by the scientific community and are linked to joint deformities.1, 2 Tendon problems have even been posited as being one of the most powerful predictors of early RA.3 Sophisticated imaging techniques developed in the last few decades, such as MRIs and ultrasound, can reveal connective tissue damage in joints caused from RA that are not seen in x-rays.4 Bursitis, inflammation of the fluid-filled sacs that protect joints5, often accompanies tenosynovitis. RA is also implicated as a cause of cartilage damage in knees.4
In my particular RA case, damage to soft and connective tissue before bone damage to joints occurs is a typical presentation. Two symptoms now linked to RA which I personally experienced before an official diagnosis were iritis – inflammation in the eyes, and torn Achilles tendons and bursitis in my ankles resulting in three surgeries. An MRI taken at the onset of my RA diagnosis revealed cartilage damage in one knee. And just last week, an MRI revealed a 50% tear of a tendon in my elbow. The elbow joint, while actively inflamed, did not yet show bone erosions.
Although not publicly well known, scientists and doctors have recognized for some time that rheumatoid arthritis is also linked to an increased risk for cardiovascular disease (CVD) including heart attack, stroke and diabetes. Systemic inflammation inherent in rheumatoid arthritis may play a role in the increased CVD risk.7 Some researchers have even called for the development of specific CVD predictors for RA patients as a special population with unique characteristics.8 Systemic inflammation involved with RA can impact the complex metabolic processes of the body including use of food for energy, sugar processing, insulin production, production of fats and lipids, body weight, and physical activity. Whenever one of these interconnected systems gets out of normal parameters, a cascade of problems may occur which can impact cardiovascular health. This is called metabolic syndrome and involves a set of interconnected risk factors which are related to cardiovascular disease and diabetes.9 In a study published in 2013, it was found that 18-49% of RA patients also had metabolic syndrome which was significantly higher than general populations.10 These researchers also found that RA patients with higher inflammatory blood markers and those who used corticosteroids were more likely to show signs of metabolic syndrome leading to increased cardiovascular risk which can have serious and fatal consequences.
As an autoimmune disease, RA can cause the body to attack itself in many different ways – not just in bones and joints. RA patients and doctors need to be aware of the numerous extra-articular (outside the joint) manifestations of the disease, carefully monitor them, and treat as needed. The stereotype of RA as “just arthritis” needs to be challenged and it needs to be seen as a hideous disease that can attack many different tissues and systems in the body.