Kim SA, et al. – This research explored the factors affecting fatigue severity in patients with obstructive sleep apnea (OSA). It was observed that fatigue severity was more likely to be associated with younger age, sleepiness, and insomnia. And it was less likely to be directly associated with OSA severity.

Methods

• 633 OSA patients who were diagnosed by polysomnography were examined.
• All patients completed sleep questionnaires including self–reported sleep duration, the Fatigue Severity Scale (FSS), the Korean version of Epworth Sleepiness Scale (K–ESS), Insomnia Severity Index (ISI), Korean version of Pittsburgh Sleep Quality Index (K–PSQI) and Beck Depression Inventory–2 (BDI–2).

Results

• The subjects had a mean age of 48.7 ± 10.5 years.
• 72.5% (n = 459) were men.
• The subjects were distributed as follows: 160 with mild, 168 with moderate and 305 with severe OSA.
• A multiple regression model found that age (β = –0.146, P = .005), K–ESS (β =–0.689, P < .001), 8 ≤ ISI score < 15 (β= 3.801,P = .006), 15≤ISI score (β = 4.565, P = .009), and K–PSQI (β = 0.684, P = .002) were predictors of a higher FSS score.
• BDI–2 (β = 0.007, P = .918), apnea–hypopnea index (AHI) (β = –0.006, P = .895), arousal index ( β = 0.034, P = .415), and nadir O₂ saturation ( β = –0.044, P = .655) were not associated with FSS score.