Fibromyalgia: gender differences and sleep-disordered breathing

Abstract

Objectives: The prevalence of fibromyalgia (FM) is much lower in men than in women. Therefore, current knowledge about this chronic pain syndrome emerged mainly from research on women. The aim of the present study was to compare clinical symptoms and sleep parameters between male and female FM patients.

Methods: Forty FM patients (18 men and 22 women) aged 48.00±8.45 years were evaluated with questionnaires on pain, sleep, fatigue, depression, anxiety and functional impact, and polysomnography (PSG).

Results: 61% of male FM patients had an apnea-hypopnea index (AHI) greater than 15, compared to 31.8% of women, and a desaturation index (DI) above five, which was twice more prevalent in men than in women. In addition, males had poorer sleep quality (16.05±2.92% vs. 13.08±3.88%; p=0.01) and slow wave sleep (SWS) (stage 3 duration: 9.02±7.84% vs. 14.44±7.32%; p=0.03) than women. No differences were found between the two groups in the level of pain, emotional distress, or daily functioning. However, pain in men, fatigue in women, and functional impact in both sexes seemed to be related to worse sleep quality. Also in women, alterations in total sleep time (TST) and rapid eye movement (REM) sleep features appeared to be related to emotional status.

Conclusions: Alterations in sleep respiratory patterns were more highly prevalent in male than in female FM patients. More so in male FM patients, the alterations in sleep patterns, non-refreshing sleep, and other FM-related symptoms observed in this population might be part of a primary sleep-disordered breathing.