Fibromyalgia is prevalent in women with deep infiltrating endometriosis and significantly lowers their health-related quality of life, researchers from Spain report.
The study, “Prevalence of fibromyalgia among women with deep infiltrating endometriosis,” was published in the International Journal of Gynecology & Obstetrics.
Endometriosis is classified into three types based on the region affected — superficial peritoneal, ovarian, and deep infiltrating. In deep infiltrating endometriosis, several regions such as the ovaries, vagina, and intestinal canal can be affected and cause severe pain.
Pain is a common symptom of endometriosis; however, the prevalence of fibromyalgia — widespread pain and discomfort in the muscles and joints — in endometriosis remains unclear. Moreover, there is insufficient information about its impact on women with different types of endometriosis.
Researchers assessed the prevalence of fibromyalgia in women with different types of endometriosis at the Hospital Clinic of Barcelona between April 6, 2015, and March 31, 2017. They also evaluated the impact of fibromyalgia on patients’ health-related quality of life (HRQoL).
The study included 80 women with deep infiltrating endometriosis (DIE group) and 76 women with superficial or ovarian endometriosis (non-DIE group). Also, 73 women without endometriosis or any joint or autoimmune conditions were included as controls.
The mean age of the participants in the DIE, non-DIE and control groups was 35.3, 35.8, and 34.7 years, respectively. All the women were premenopausal and had a body mass index of less than 30.
The London Fibromyalgia Epidemiological Study Screening Questionnaire (LFESSQ) was used to assess fibromyalgia in the study population. LFESSQ is a six-item questionnaire. It has two components — LFESSQ-4, with questions about widespread pain, and LFESSQ-6, with questions about both pain and fatigue. The patient is considered to have fibromyalgia if both components are fulfilled.
Researchers found that fibromyalgia was prevalent in women with DIE compared with the rest of the study population. More women in the DIE group (31; 39%) met the LFESSQ-4 score compared with those in the non-DIE (12; 16%) and control groups (6; 8%). A similar trend was noted in those who met the LFESSQ-6 score as well (28%, 11%, and 5%).
The 36-Item Short Form (SF-36) questionnaire was used to assess the patients’ HRQoL. The SF-36 consists of eight sections covering physical functioning, energy/fatigue, bodily pain, role limitations due to physical health, general health perception, social functioning, role limitations due to emotional problems, and emotional well-being. The questions are scored on a scale of 0-100. The lower the score, the greater the disability.
Women with DIE experience a significant reduction in their HRQoL as indicated by a significantly lower score in all the questions in SF-36 compared with those in non-DIE and control groups.
Moreover, the SF-36 can be divided into two components: the items that evaluate the physical quality of life (physical component summary, or PCS) and those that assess the emotional quality of life (mental component summary, or MCS).
The percentage PCS score was significantly lower in the DIE group (68.1) compared with the non-DIE (82.4) and control groups (88.9). Similarly, the percentage MCS score in the DIE, non-DIE and control groups was 68.1, 79.1, and 81.9 respectively.
Statistical analysis showed a correlation between fibromyalgia diagnosis in women with DIE and the reduction in HRQoL. Women with DIE who screened positive for fibromyalgia (as per LFESSQ) also tended to have lower PCS and MCS scores.
“The estimated prevalence of fibromyalgia was higher among women with DIE. Women with DIE and positive fibromyalgia screening had lower HRQoL,” the authors stated. “Further studies are needed to confirm whether women with DIE have an increased risk of fibromyalgia.”