Sleepiness in patients with moderate to severe sleep-disordered breathing

BACKGROUND: Population-based studies suggest that complaints of sleepiness are absent in many individuals with sleep-disordered breathing. We investigated the prevalence of sleepiness as well as factors associated with sleepiness in individuals with moderate to severe sleep-disordered breathing (apnea-hypopnea index > or = 15). DESIGN: Cross-sectional study. SETTING: The Sleep Heart Health Study. PARTICIPANTS: Sleep Heart Health Study participants (N = 6440). MEASUREMENTS AND RESULTS: Sleepiness was defined as an Epworth Sleepiness Scale score >10 or a report of at least frequently feeling unrested or sleepy. Forty-six percent of participants with moderate to severe sleep-disordered breathing (n = 1149) reported sleepiness. Characteristics associated with sleepiness after adjustment for confounders included presence of respiratory disease, shorter self-reported weekday and weekend sleep, sleep durations, complaints of insufficient sleep, complaints of sleep maintenance insomnia, early morning awakening, habitual snoring, and complaints of awakening with leg cramps or leg jerks. Some respiratory polysomnography measures were associated with sleepiness, but sleep-stage percentages and measures of sleep disruption were not. CONCLUSIONS: In this community-based cohort, subjective sleepiness is absent in many individuals with significant sleep-disordered breathing. Comorbid conditions, including respiratory disease, sleep restriction, insomnia, and nocturnal leg complaints, are important risk factors for sleepiness in individuals with moderate to severe sleep-disordered breathing.