Introduction: Sleep breathing disorders (SBD) are a relevant comorbidity in IPF. Differences in SBD prevalence, features and impact may depend on the methodology used. We evaluated the SBD features and the treatment effect depending on the type of methodology: systematic sleep study (SSS) versus conventional study due to clinical SBD suspicion.

Methodology: SBD study in two IPF cohorts; a retrospective cohort (RC) and a prospective cohort (PC) with SSS in consecutive patients that initiated anti-fibrotic treatment. Polysomnography, biomarkers and quality of life were performed at inclusion and after 1-year in PC. Mortality, IPF progression and exacerbations were compared. SBDs were classified into obstructive sleep apnea (OSA), central sleep apnea (CSA), and sleep-related hypoxemia (SRH). SBD were treated with CPAP and/or nocturnal oxygen therapy (NOT) as appropriate.

Results: 181 IPF patients (131 RC and 50 PC) were included. RC identified 12% OSA, while PC found 70% SDB, 36% OSA, 22% CSA and 12% SRH. CPAP was used in 11% of RC and 54% of PC. NOT was used in 16% of PC. No differences in IPF progression or mortality were found between cohorts at one year. PC showed fewer mild-moderate exacerbations (p=0.002). PSG under SBD treatment found improved SBD, but 6/35 patients had to add NOT or CPAP. 5/15 patients without SBD at baseline presented SBD at one year and initiated appropriate treatment. MMP-1 was higher in IPF patients with OSA and CSA that decreased after 1-year of SBD treatment (p=0.029 and p=0.027).

Conclusions: The systematic study of SBD identifies subclinical sleep disorders, including OSA, that may require specific treatment. SBD and its treatment may influence in some profibrotic pathways.