Severe obstructive sleep apnea: sleepy versus nonsleepy patients

To compare demographic and polysomnographic data of sleepy versus nonsleepy severe obstructive sleep apnea (OSA) patients according to the Epworth Sleepiness Scale (ESS).

Retrospective cohort.

Six hundred forty-four consecutive severe (apnea-hypopnea index [AHI] >or= 30) adult OSA patients who underwent a polysomnographic evaluation in our sleep disorders unit. ESS data were available in 569 (88.3%). Three hundred twenty-seven (57.5%) patients had ESS > 10.

Sleepy severe OSA patients are slightly younger and more obese than nonsleepy patients. These sleepy patients have shorter sleep latency and lower percentage of slow wave sleep. They consistently show a higher AHI, both supine and lateral AHI, have a higher number of short arousals, and a higher arousal index. They also have higher snoring loudness in the supine and both lateral positions and a lower minimal SaO(2) in rapid eye movement and non-rapid eye movement sleep. After adjusting for confounders, a logistic regression model points to apnea index as a significant prognostic factor for excessive daytime sleepiness.

Severe OSA sleepy patients have a syndrome that is significantly more severe than nonsleepy patients. Sleepy patients have worse sleep-related breathing parameters, and their sleep patterns are lighter and more fragmented than nonsleepy patients. Apnea index appears as an important prognostic factor for excessive daytime sleepiness.