Fatigue in sleep apnea: the role of depressive symptoms and self-reported sleep quality

OBJECTIVES OR BACKGROUND: Obstructive Sleep Apnea (OSA) is characterized by partial or complete cessation of breath during sleep. OSA is associated with increased cardiovascular risk as well as psychosocial complications such as daytime somnolence, depression, and fatigue. The goal of the present study was to better understand fatigue in OSA by examining self-reported sleep quality, depressive symptoms, excessive daytime sleepiness, and OSA severity in a group of newly diagnosed OSA patients.

Two hundred and forty newly diagnosed OSA patients enrolled in the study. Participants completed several questionnaires at baseline.

Depressive symptoms accounted for 15% of variance in fatigue beyond that of demographics and OSA severity (p<0.001). Self-reported sleep quality accounted for 11% of variance beyond that of depressive symptoms (p<0.001). The total model accounted for 48% of the variance in fatigue. Post hoc analysis found that the total model accounted for only 14% of the variance in sleepiness (as measured by the Epworth Sleepiness Scale).

The current study confirms the findings of previous OSA studies, which found depressive symptoms have a greater association with fatigue than OSA disease severity variables. This study extends those findings by showing that self-reported sleep quality is independently associated with fatigue, even after taking into account demographic, comorbid conditions, OSA disease severity, sleepiness, and depressive symptoms. The role of sleep quality as an independent contributor to daytime fatigue in OSA may be under appreciated. Sleep quality should be closely followed in the clinical management of OSA.