Nocturnal Hypoxemia Associates With Symptom Progression and Mortality in Patients With Progressive Fibrotic Interstitial Lung Disease

Background

OSA and nocturnal hypoxemia (NH) are common in patients with fibrotic interstitial lung disease (F-ILD), but their relationship with disease outcomes remains unclear.

Research Question

What is the relationship between NH and OSA and clinical outcomes in patients with F-ILD?

Study Design and Methods

This was a prospective observational cohort study of patients with F-ILD and without daytime hypoxemia. Patients underwent home sleep study at baseline and were followed up for at least 1 year or until death. NH was defined as ≥ 10% of sleep with oxygen saturation of < 90%. OSA was defined as an apnea-hypopnea index of ≥ 15 events/h.

Results

Among 102 participants (male, 74.5%; age, 73.0 ± 8.7 years; FVC, 2.74 ± 0.78 L; 91.1% idiopathic pulmonary fibrosis), 20 patients (19.6%) demonstrated prolonged NH and 32 patients (31.4%) showed OSA. No significant differences were found between those with and without NH or OSA at baseline. Despite this, NH was associated with a more rapid decline in both quality of life as measured by the King's Brief Interstitial Lung Disease questionnaire (change, –11.3 ± 5.3 points in the NH group vs –6.7 ± 6.5 in those without NH; P = .005) and higher all-cause mortality at 1 year (hazard ratio, 8.21; 95% CI, 2.40-28.1; P < .001). No statistically significant difference was seen between the groups in annualized change in measures of pulmonary function testing.

Interpretation

Prolonged NH, but not OSA, is associated with worsening disease-related quality of life and increased mortality in patients with F-ILD.