Sleep quality in women with endometriosis

Because endometriosis is a complex condition that can negatively impact sleep, a recent study assessed the multifactorial variables associated with poorer quality of sleep in women with the disorder.

The study in the Journal of Women’s Health found that poorer overall quality of sleep was significantly associated with worse quality of life, more depression symptoms, and painful bladder syndrome (PBS).

“Sleep is important for chronic pain and for health in general,” said principal investigator Paul Yong, MD, PhD, an associate professor of ob/gyn at the University of British Columbia in Vancouver, Canada. “We wanted to further investigate the role of sleep in patients with endometriosis, a common cause of chronic pelvic pain.”

Methods
Data from the Endometriosis Pelvic Pain Interdisciplinary Cohort (EPPIC) data registry were analyzed for women with histopathological confirmation of endometriosis who underwent surgery at the BC Women's Center for Pelvic Pain and Endometriosis between June 2015 and June 2017. 

A total of 275 women met the study criteria, of whom 86.5% had superficial endometriosis; however, 28.7% also had an ovarian endometrioma cyst and 18.5% had deep infiltrating endometriosis at the time of surgery.

The primary outcome was quality of sleep preoperatively, from the Chronic Pain Sleep Inventory (CPSI), based on a 0 to 100 standardized visual analogue scale (VAS), with 0 indicating the poorest quality of sleep and 100 the best quality of sleep.

Findings
Poorer overall quality of sleep was independently connected to worse quality of life via the Endometriosis Heath Profile-30 (EHP-30) (beta = -0.18; P = 0.0026); more depression symptoms via the Patient Health Questionnaire-9 (PHQ-9) (beta = -1.62; P < 0.001); and PBS (beta = -5.82; P = 0.035).

“Our findings indicate that a1-point increase in the EHP-30 for  worsening quality of life, a 1-point increase in the PHQ-9 for worsening depression, and the presence of PBS increased the primary outcome of toward poorer quality of sleep by 0.18, 1.62, and 5.82 points, respectively,” Dr. Yong told Contemporary OB/GYN. 

However, patients with endometriomas and more severe endometriosis had overall better quality of life, perhaps because they tended to be referred for infertility and/or surgical management of a pelvic mass detected on imaging, as opposed to referral for pain symptoms.

Improved sleep was also significantly linked to higher education (graduate degree or higher) and the presence of an ovarian endometrioma cyst.

Conclusions
Dr. Yong is not surprised by any of the study’s findings, which also found an independent relationship between poorer sleep quality and depression, rather than anxiety.

“Although depression and PBS may be consequences of poor sleep, they may also be causes of poor sleep, resulting in a positive feedback cycle,” he said.

Repositioning during sleep may alleviate myofascial trigger points associated with PBS. Conversely, poor sleep might reduce pain thresholds but exacerbate PBS.

“It is possible that treating depression, as well as PBS to reduce nocturia, may improve sleep in patients with endometriosis,” Dr. Yong said.

The hormone melatonin is also a promising treatment adjunct for these patients.

Dr. Yong said research on interventions that improve sleep is warranted as part of the management of some women with endometriosis. He also believes that a clinical trial of treatment of depression or PBS in endometriosis patients, with sleep as one of the outcomes, would be enlightening.