Effects of continuous positive airway pressure on fatigue and sleepiness in patients with obstructive sleep apnea: data from a randomized controlled trial

Abstract

Objectives: Complaints of fatigue are frequent in patients with obstructive sleep apnea (OSA); however, the impact of continuous positive airway pressure (CPAP) on fatigue remains unclear.

Methods: Fifty-nine men and women with OSA were randomly assigned to therapeutic or placebo CPAP in a double-blind fashion for a 3-week intervention period. Four outcome measures were assessed: (1) fatigue/vigor measured with the Multidimensional Fatigue Symptom Inventory--Short Form (MFSI-sf), the (2) fatigue and (3) vigor subscales of the Profile of Mood States--Short Form (POMS), and (4) the Epworth Sleepiness Scale (ESS). Data were analyzed using repeated-measures analysis of variance.

Results: Compared with patients receiving placebo CPAP, those patients treated with therapeutic CPAP showed significant reductions in the apnea-hypopnea index, as well as decreases in both measures of fatigue and increases in vigor (P values < 0.05). The beneficial effect of therapeutic treatment was most pronounced in patients with high levels of fatigue at study onset. Significant treatment effects in sleepiness scores were not observed in the entire sample (P > 0.05); however, in a subset of patients with excessive sleepiness at the onset of treatment, ESS scores were significantly reduced with use of therapeutic CPAP (P < 0.05).

Conclusions: Results suggest that 3 weeks of therapeutic CPAP significantly reduced fatigue and increased energy in patients with OSA. Therapeutic CPAP significantly reduced daytime sleepiness in patients who reported excessive sleepiness at the onset of treatment.

Keywords: Obstructive sleep apnea; continuous positive airway pressure; energy; fatigue; sleepiness; vigor.

Figure 1

Recruitment profile

Figure 2

MFSI-sf Total scores in the therapeutic (baseline 8.76 ± 16.84 vs. post-treatment −0.10 ± 14.80) and placebo-CPAP (baseline 5.77 ± 14.96 vs. post-treatment 4.20 ± 16.00) groups at baseline and after three weeks of treatment. There was a significant time-by-treatment interaction (F_1,57 = 5.49, P = 0.02, η² = 0.09).

Figure 3

POMS fatigue scores in the therapeutic (baseline 7.17 ± 6.30 vs. post-treatment 4.03 ± 4.46) and placebo-CPAP groups (baseline 6.27 ± 5.05 vs. post-treatment 5.77 ± 5.42) at baseline and after three weeks of treatment. There was a significant time-by-treatment interaction (F_1,57 = 5.23, P = 0.03, η² = 0.08)

Figure 4

POMS vigor scores in the therapeutic (baseline 14.28 ± 7.39 vs. post-treatment 16.52 ± 5.97) and placebo-CPAP groups (baseline 15.33 ± 6.69 vs. post-treatment 14.27 ± 7.87) at baseline and after three weeks of treatment. There was a significant time-by-treatment interaction (F_1,57 = 5.94, P = 0.02, η² = 0.09).