Sleep quality and associated daytime consequences in patients with idiopathic pulmonary fibrosis

The aim of this study was to describe sleep quality and associated daytime consequences in idiopathic pulmonary fibrosis (IPF).

Fifteen patients with IPF and 15 control subjects matched on age and anthropometric variables were included in the study. Sleep quality and its daytime consequences were assessed by clinical interview, the Pittsburgh Sleep Quality Index (PSQI), the Functional Outcomes in Sleep Questionnaire (FOSQ), the Fatigue Severity Scale (FSS), the Epworth Sleepiness Scale and attended all-night polysomnography.

Polysomnography revealed a decrease in sleep efficiency and slow wave sleep, and an increase in stage 1 sleep and arousal index in IPF patients compared to controls. Daytime tachypnea persisted during sleep. Oxygen saturation below 90% was observed during 34.3 +/- 37.3% of the total sleep time (TST). Quality of sleep and daytime function were moderately to significantly impaired based on the PSQI and FOSQ. The total FOSQ score was negatively correlated with TST with oxygen saturation below 90% (p = 0.01, r = -0.62). FSS scores were correlated with TST at oxygen saturation below 90% and mean oxygen saturation during sleep (p = 0.002, r = 0.74, and p = 0.007, r = -0.66, respectively).

Our data suggest significant sleep disruption and consequent impairment of physical and social functioning in patients with IPF. In the absence of effective treatments for IPF, the improvement of sleep quality should be a primary therapeutic goal.