Sex-Related Differences in Sleep-Related PSG Parameters and Daytime Complaints in a Clinical Population

Abstract

Background

Recent research suggested that perception of sleep impairments might present sex-related effects (ie, women appear to be more prone to report fatigue rather than sleepiness). The latter has been evidenced in sleep-related breathing disorders (SRBD). Differently, it has been suggested that sleep-related movement disorders may also be associated to fatigue rather than to sleepiness. Whether sex-related differences would be similar irrespective of diagnosis remains unclear.

Methods

During a one-year period, systematic clinical evaluation, by means of structured symptom scales, was performed for a cohort of 921 consecutive patients attending an academic sleep center for polysomnography. The Brugmann Fatigue Scale (BFS), an instrument designed for the assessment of rest propensity was used among other scales (ie, Epworth Sleepiness Scale, ESS). According to inclusion and exclusion criteria, 420 men and 376 women were finally included in the study and retained for data analysis.

Results

While men and women presented with similar age, BMI, total sleep time and sleep efficiency, men presented with higher levels of respiratory events and more periodic limb movements. Irrespective of diagnosis, women presented with significantly higher levels of sleep-associated complaints on all scales. Comparative stratifications of daytime symptoms, per diagnostic groups (SRBD, Movement Disorders (SRMD) and Insomnia), revealed significant main effects for diagnosis alongside with main effects of biological sex. Associations between common markers of disease severity for SRBD or SRMD and sleep or rest propensity, respectively, only showed significant correlation between periodic limb movements and rest propensity. The strength of association was similarly significant for both sexes.

Conclusion

While men displayed more objective impairment on polysomnography (PSG) and lower symptom levels, the opposite was true in women. However, both men and women present with statistically significant associations between SRMD severity (PLMS index) and physical fatigue.

Keywords:

• sleep-related sex effects
• fatigue
• rest propensity
• sleepiness
• sleep propensity

Abbreviations

AHI, Apnea–Hypopnea Index; ArI, Arousal Index; BFS, Brugmann Fatigue Scale; BFS Ψ, Brugmann Fatigue Scale (mental rest propensity subscale); BFS Φ, Brugmann Fatigue Scale (physical rest propensity subscale); BMI, Body Mass Index; ESS, Epworth Sleepiness Scale; FSS, Fatigue Severity Scale; HADRS, Hospital Anxiety and Depression Rating Scale; HADA, Hospital Anxiety and Depression – Anxiety subscale; HADD, Hospital Anxiety and Depression – Depression subscale; ID, Insomnia Disorders; ODI, Oxygen Desaturation Index; OSA, obstructive sleep apnea; PLM, Periodic Limb Movements; PLMSI, Periodic Limb Movements during Sleep Index; PSG, Polysomnography; PSQI, Pittsburgh Sleep Quality Index; RDI, Respiratory Disturbance Index; REM, Rapid Eye Movement; REMLAT, REM sleep latencies; RERA, respiratory effort-related arousal; RLS, restless legs syndrome; SE, sleep efficiency; SOL, sleep onset latency; SRBD, sleep-related breathing disorders; SRMD, sleep-related movement disorders; SWS, slow-wave sleep; TIB, time in bed; TST, total sleep time; USD, unspecified sleep disorder; WASO, wake after sleep onset.

Acknowledgments

An adapted version of the abstract of this paper has been presented at the 15^th World Sleep Congress (Vancouver, Canada, September 20–25, 2019) as a poster presentation with interim findings. The poster’s abstract was published in “Poster Abstracts” in Volume 64, supplement 1 of Sleep medicine: https://doi.org/10.1016/j.sleep.2019.11.773.

Author Contributions

DN, SVE, OM: script writing and data analyses. SVE, JN: data collection and review. DN, OM and CK: supervision, logistics and review. All authors contributed to data analysis, drafting or revising the article, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.