Effect of CPAP on Symptoms of Patients With Fibromyalgia and Obstructive Sleep Apnea

Overview

Fibromyalgia (FM) is a chronic pain disorder associated with a wide spectrum of sleep disorders. In fact, insomnia and waking unrefreshed are currently considered part of the criteria for diagnosis. Recent studies show that sleep quality and symptoms of FM are inversely correlated. Obstructive sleep apnea (OSA) is a sleep disorder characterized by repeated episodes of complete or partial blockage of the upper airway. Nonrestorative sleep and fatigue are common symptoms of FM and OSA and may suggest related pathophysiology or co-morbidity that is yet to be diagnosed. This prospective randomized controlled clinical trial will enroll adult FM patients who screen positive for OSA by the STOP-Bang questionnaire. OSA will be confirmed by a laboratory polysomnography (PSG) study. After undergoing further baseline questionnaires and investigations, patients confirmed to have FM with moderate to severe OSA will be randomized to one of two different treatments: 1) Treatment for FM at the Chronic Pain Clinic together with Continuous Positive Airway Pressure (CPAP) devices for their OSA OR 2) Control group receiving treatment for FM at the Chronic Pain Clinic only.

Sleep, pain and breathing have a complex multidimensional relationship. Pain disturbs sleep, poor sleep alters the perception of pain and sleep is a vulnerable state of breathing. The central system sensitization affecting the sensation of widespread pain in FM is due to a decrease in the neurophysiologic inhibition of perception of painful stimuli. This is caused by disturbed sleep. Rheumatic disease pathology can be understood in the light of the interference of cytokines and cellular immune functions with the sleeping/waking brain. Sleep disturbances such as unrefreshing sleep, difficulty falling asleep and frequent night awakenings have been reported by over 90% of FM patients. Sleep disturbances may be related to depression through pain and alteration of physical functioning. Depression and sleep disturbances have been proven to contribute to fatigue in FM patients. Although non-restorative sleep and fatigue are the most commonly reported symptoms by FM patients, the exact cause of these problems is not well understood. A study reported that 50% of the women with obstructive sleep apnea syndrome or upper airway resistance syndrome had chronic pain and more than 11 tender points. One case report has suggested OSA as a possible cause for FM. No studies have been conducted to demonstrate the effect of CPAP treatment on symptoms of FM syndrome in patients with OSA.