Many women with rheumatoid arthritis also have endometriosis, a painful condition where the tissue that normally lines the endometrium (inside the uterus) grows outside the uterus. Endometriosis affects the ovaries, fallopian tubes, and the tissue lining the pelvis.
Studies have linked endometriosis to different autoimmune conditions, including systemic lupus erythematosus (SLE), Sjogren’s syndrome, and multiple sclerosis. Researchers have also recently found connections between endometriosis and rheumatoid arthritis (RA), an autoimmune or inflammatory condition where the immune system malfunctions and attacks healthy tissues, mainly the synovium (the lining of the joints).
What to Know About Endometriosis
While endometriosis only affects 10 percent of women, it is linked to numerous chronic diseases, including cancer, autoimmune diseases, and cardiovascular disease — according to a 2015 report in the journal Human Reproduction Update.
Some women with endometriosis do not experience symptoms and, for those who do, it can take 4 to 11 years from the first symptoms to a diagnosis.
Common symptoms of endometriosis include:
- Abdominal and back pain
- Heavy and irregular periods
- Painful menstrual cramping
Endometriosis is a chronic condition that can affect a person throughout their life. There is no cure for endometriosis, but treatments like surgery, hormone treatments, and pain medications can help manage its effects. Clinical trials are also underway to see if RA drugs like DMARDS can also help treat endometriosis.
While there’s no way to prevent endometriosis, a few lifestyle strategies like exercising regularly and limiting processed foods, alcohol, and caffeine can help keep your estrogen at normal or lower levels.
The Link Between Rheumatoid Arthritis and Endometriosis
A 2021 study in the journal Rheumatology revealed people with endometriosis have a higher risk for RA.
“This study — performed using data derived from a national health care database in Taiwan — confirms previous publications that have suggested a relationship between endometriosis and a number of autoimmune diseases, in this case, rheumatoid arthritis,” explains Lisa R. Sammaritano, MD, a rheumatologist at Hospital for Special Surgery in New York City.
“While provocative and interesting, the available published data are limited in quality (and quantity) and do not yet provide a clear mechanism or explanation for this association,” she explains.
A 2019 meta-analysis found that only five of 26 studies identified in the systematic literature review provided high-quality evidence; of these, four supported a statistically significant association between endometriosis and at least one autoimmune disease:
- Rheumatoid arthritis
- Systemic lupus erythematosus
- Sjogren’s syndrome
- Chronic liver disease
- Multiple sclerosis
- Inflammatory bowel disease
Dr. Sammaritano cites another study from 2016 reported in the journal Annals of Rheumatic Diseases that “identified a statistically significant association of laparoscopically-confirmed endometriosis (the “gold standard” for diagnosis) with subsequent diagnosis of both SLE and RA.”
Similarities Between RA and Endometriosis
Both RA and endometriosis cause chronic inflammation. Inflammation is the body’s response to trauma or foreign substances like viruses and bacteria.
“Endometriosis is best described as an estrogen-dependent, chronic inflammatory condition characterized by the proliferation of endometrial glands and stromal tissue outside the uterine cavity,” Dr. Sammaritano explains. “Ongoing inflammation and scarring lead to the typical complications of pain and infertility. It is known to be driven by both hormonal and immunologic factors.”
In RA, the body’s immune malfunctions and starts attacking its healthy tissues with inflammation. Endometriosis, which has not yet been classified as an autoimmune disease, can sometimes behave like one.
“Immune system abnormalities have been documented in multiple types of immune cells and inflammatory pathways in patients with endometriosis,” says Dr. Sammaritano. “Not surprisingly, some of these changes are similar to various immune system abnormalities found in autoimmune disorders, with persistent chronic inflammation.”
RA and Endometriosis: The Genetic Link
Your risk for RA is higher if you have family members with the condition. According to the American College of Rheumatology, the disease rate in parents, children, and siblings of people with RA is around 0.8 percent compared to 0.5 percent of the population. Genes play a small role, and that risk further increases based on other risk factors, including age, gender, and smoking.
Endometriosis also runs in families, and your risk for the condition is higher if other family members have the disease. Research shows a seven to 10 times greater risk for endometriosis for women who have a first-degree relative (i.e., mother or sister) with the condition.
“Changes or defects in the immune system appear to allow each of these disorders to develop and persist, likely in conjunction with other anatomic and environmental factors,” says Dr. Sammaritano.
She further notes that “there are known genetic factors that influence the risk of endometriosis, just as there are for RA and other autoimmune disorders. Whether the precise genetic markers are identical or somehow linked is not known.”
Paying Attention to Symptoms
People living with RA should be aware of endometriosis, its symptoms, and any risk factors, such as family history, they have. The same goes for people with endometriosis who have a family history of RA.
Early diagnosis and treatment are vital for both conditions and lead to better health outcomes. Talk to your doctor about your risk factors and don’t be afraid to bring up any abdominal pain, menstrual, or fertility issues you’ve having at your next appointment.
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American College of Rheumatology. Genetics and Rheumatic Disease. https://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Living-Well-with-Rheumatic-Disease/Genetics-and-Rheumatic-Disease
Harris, H, et al. “Endometriosis and the Risks of Systemic Lupus Erythematosus and Rheumatoid Arthritis in the Nurses’ Health Study II.” Annals of the Rheumatic Diseases. July 2016. doi: https://doi.org/10.1136/annrheumdis-2015-207704.
Interview with Lisa R. Sammaritano, MD, a rheumatologist at Hospital for Special Surgery.
Kvaskoff, M, et al. “Endometriosis: A High-Risk Population for Major Chronic Diseases?” Human Reproduction Update. July 2015. doi: https://doi.org/10.1093/humupd/dmv013.
Mena, G, et al. “The Effect of Physical Activity on Reproductive Health Outcomes in Young Women: A Systematic Review and Meta-Analysis.” Human Reproduction Update. September 11, 2019. doi: https://doi.org/10.1093/humupd/dmz013.
Nouri, K, et al. “Family Incidence of Endometriosis in First-, Second-, and Third-Degree Relatives: Case-Control Study.” Reproductive Biology and Endocrinology. 2010. doi: https://doi.org/10.1186/1477-7827-8-85.
Xue, Y et al. “Increased Risk of Rheumatoid Arthritis among Patients with Endometriosis: A Nationwide Population-Based Cohort Study.” Rheumatology. July 1, 2021. doi: https://doi.org/10.1093/rheumatology/keaa784.