Neither obstructive sleep apnea nor nocturnal hypoxemia is associated with mortality in idiopathic pulmonary fibrosis patients

<bold>Introduction:</bold> Obstructive sleep apnea (OSA) has been recognized as an important comorbidity in the latest guidelines for idiopathic pulmonary fibrosis (IPF). OSA is common in patients with IPF and is associated with worse prognosis. The latest reports suggests that nocturnal hypoxemia (NH) and not OSA drives this relation. We aimed to assess the relationship between OSA, NH, and survival in patients with IPF. <bold>Methods:</bold> Patients with IPF underwent home cardio-respiratory monitoring (CRM) at baseline, and if it fulfilled the criteria for OSA, they were offered referral. Patients were followed for 36 months or until death. The criteria for OSA were based on international guidelines (AHI ≥15 or AHI ≥ 5 and Epworth sleepiness score ≥ 11 or comorbidities), and NH was defined as > 10% of sleep with SaO2 < 90%. The primary outcome measure was mortality. <bold>Results:</bold> Among 150 participants, 122 completed CRM and an 7 were already diagnosed with OSA and had a CRM in the records. A total of 69 (53%) fulfilled the criteria for OSA, and 45 (35%) had NH. Patients with NH had significantly reduced DLCO % predicted and KBILD score as well as a tendency towards lower FVC % predicted, 6-minute walk test distance, and health-related quality of life (SGRQ-I) score at baseline. No difference was seen among the baseline values for patients with OSA and OSA was not associated with increased mortality. In unadjusted analyses, NH was associated with increased mortality, but this association was not significant after adjustment for gender, age, and lung function. <bold>Conclusion:</bold> OSA or NH was not significantly associated with mortality, but NH was associated with reduced DLCO and quality of life.