The study, “Prevalence of fibromyalgia among women with deep infiltrating endometriosis,” was published in the International Journal of Gynecology & Obstetrics.
Endometriosis is a disease characterized by overgrowth of endometrium cells — those that line the womb — elsewhere in the body. Women with this disorder often experience acute inflammation, chronic pain, and infertility.
The underlying cause of endometriosis is still not very well-understood, but studies have suggested a potential association with other disorders including fibromyalgia. A better understanding of the relationship between these diseases may help improve patient care and symptom management.
To explore this, researchers in Spain conducted an observational study to examine the prevalence of fibromyalgia in women with endometriosis and how it affects quality of life.
The study enrolled 229 women, 80 of whom had deep infiltrating endometriosis (DIE), 76 had superficial endometriosis lesions, and 73 who did not have endometriosis or any rheumatologic or autoimmune disease (control group). All participants were premenopausal (ages 18 to 40 years old) and were not obese, with a body mass index (BMI) below 30.
Women with deep infiltrating lesions were found to have significantly more pain than the other two groups.
Overall, 83% of these women reported having moderate to severe painful periods, 74% had moderate to severe painful sexual intercourse, and 21% had moderate to severe chronic pelvic pain. These pain symptoms were reported by significantly fewer women without deep infiltrating lesions (63%, 16% and 9%, respectively) and women in the control group (26%, 1% and 0%).
Based on the results of the London Fibromyalgia Epidemiological Study Screening Questionnaire (LFESSQ), the researchers found that more women in the deep infiltrating endometriosis group fulfilled the criteria for a fibromyalgia diagnosis.
A total of 31 (39%) women in the DIE group, 12 (16%) in the non-DIE group, and six (8%) in the control group fulfilled the four pain criteria of the LFESSQ consistent with a fibromyalgia diagnosis. Taking into account both the pain and fatigue diagnostic criteria of the screening tool, 22 (28%) in the DIE group, eight (11%) in the non-DIE group, and four (5%) in the control group were considered to have fibromyalgia.
These results suggest that the prevalence of fibromyalgia in women with deep endometriosis lesions is more than the double that of those with less severe endometriosis (7% vs 2.8%).
Evaluation of participants’ quality of life revealed that those with deep infiltrating endometriosis had a poorer health-related quality of life. In addition, those who screened positive for fibromyalgia had a tendency to have even lower scores for mental health-related parameters.
“These findings suggest that women with endometriosis may require greater medical care because they not only have endometriosis-related health problems, but also have other medical illnesses with a significant impact on public health,” the researchers wrote.
Additional studies are still warranted to further explore the risk of developing fibromyalgia in women with severe endometriosis.