PURPOSE: the study aims at describing the role of sleep disordered breathing (SDB) on daytime symptoms, quality of sleep and quality of life (QoL) in patients with moderate-severe IPF.
METHODS: we enrolled 34 consecutive room air breathing IPF outpatients who received a full-night polysomnography. The following questionnaires were administered: Epworth Sleepiness Score (ESS), Pittsburg Sleep Quality Index (PSQI), StGeorge's Questionnaire (StGQ).
RESULTS: patients were classified in 3 groups:Group A (NO-SDB, 9 patients), Group B(OSAS without sleep-related hypoxemia, 17 patients), Group C(OSAS with sleep-related hypoxemia, 8 patients). Although sleep parameters showed no significant differences among the 3 groups, worse measures were found in group C. 50% of patients (17/34) reported a StGQ score indicating a reduced QoL and the StGQ score was significantly higher in group C patients compared to group A (p < 0.05). In the stepwise multiple regression analysis, 75% of StGQ score variability was significantly predicted by FVC(Forced Vital Capacity) %, DLco (diffusion lung capacity for carbon monoxide)%, PSQI and ESS.
CONCLUSIONS: in patients with IPF both subjective and polysomnographic poor sleep quality are extremely common features, they are predicted by variables associated with SBD severity and are linked to low QoL. IPF with more severe SDB present poor sleep quality and a worse QoL compared to SDB-free or OSAS-only.