Sleep Propensity and Sleep Apnea-Specific Hypoxia Are Associated With Excessive Daytime Sleepiness

Excessive daytime sleepiness is a hallmark of obstructive sleep apnea (OSA). Previous research reports substantial variability in patient-reported sleepiness for a given OSA severity, i.e., apnea-hypopnea index (AHI). This may be partly due to inadequate characterization of intermittent hypoxia or a physiologic disorder involving the central nervous system (sleep propensity, Fernandez-Mendoza et al. 2015; e.g. daytime sleepiness is more common in individuals with dementia). We assessed the separate associations between respiratory event- related desaturation, as a measure of intermittent hypoxia, and sleep depth on daytime sleepiness.