Women diagnosed with fibromyalgia and endometriosis have a higher risk of developing autoimmune diseases, a study found. Additionally, patients with both conditions had a higher incidence of mental conditions such as depression and used their healthcare system more often.
The study, “Evidence for an association between endometriosis, fibromyalgia and autoimmune diseases,” was published in the American Journal of Reproductive Immunology.
Endometriosis is a complex disease characterized by cells of the endometrium — the lining of the womb — growing elsewhere in the body. The condition is associated with acute inflammation, chronic pain and infertility.
Fibromyalgia causes chronic pain in the muscles and is sometimes accompanied by cognitive and psychiatric symptoms. The disease mainly occurs in women.
Although the diseases’ exact causes remain unknown, the immune system seems to play a crucial role in both. This is supported by studies suggesting high prevalence of fibromyalgia and autoimmune diseases in patients with endometriosis.
A group of researchers performed a retrospective study addressing the association between endometriosis, fibromyalgia, and autoimmune diseases. They used data from the computerized databases of Maccabi Healthcare Services (MHS), which contains the information of 2.1 million healthcare plan users in Israel.
Women diagnosed with either fibromyalgia or endometriosis were compared to a random sample corresponding to 10% of the insured population that did not have either condition.
Of the 781,571 adult women evaluated, 6,647 had endometriosis (mean age, 42; average time since diagnosis, eight years), 25,425 had fibromyalgia (mean age, 55; average time since diagnosis, 10 years), and 401 had both.
Forty-three percent of patients were first diagnosed with fibromyalgia; 17% were diagnosed with both conditions in the same year.
“The results of this study indicate that fibromyalgia is prevalent among 6% of women with endometriosis, compared to 3.2% of the general population,” researchers said.
Women diagnosed with endometriosis or fibromyalgia had a higher prevalence of autoimmune diseases, such as inflammatory bowel disease, systemic lupus erythematosus, and Sjögren’s syndrome, than the general population. “This suggests that both endometriosis and fibromyalgia may have an autoimmune component,” the authors stated.
Additionally, women diagnosed with both conditions also had a higher incidence of anxiety and depression, were more likely to take antidepressants, and made more use of healthcare services, especially hospitalizations.
“Our study has found that co-occurrence of endometriosis and fibromyalgia is associated with a high burden of [autoimmune diseases], depression and anxiety, and [healthcare resource utilization]. To the best of our knowledge, this is the first study to examine the association between [these conditions] in a large community-based database and may, therefore, be relevant for other populations,” the authors wrote.
They also noted that the relationship among fibromyalgia, endometriosis, and autoimmune disease should be further studied to understand its implications.