Background: Obstructive sleep apnea (OSA), nocturnal hypoxemia and excessive daytime sleepiness (EDS) are common comorbidities in people with cystic fibrosis (pwCF). Most of the data showing this originates from children and adolescents. The aim of this study was to collect data on sleep parameters, EDS and pulmonary function from a large cohort of adult pwCF.

Methods: Full overnight polysomnography (PSG) was performed. EDS was determined using the Epworth Sleepiness Scale (ESS). Demographic and clinical data (body mass index [BMI], pulmonary function, capillary blood gases) were collected.

Results: A total of 52 adult pwCF were included (mean age 30.7 ± 8.0 years, mean percent predicted forced expiratory volume in 1 s [ppFEV₁] of 52.1 ± 14.8). Overall AHI was in the normal range (4.5 ± 4.0/h); 21/52 pwCF (40%) had an apnea-hypopnea index > 5/h. Nocturnal hypoxemia was found in 25% of participants and this was associated with ppFEV₁ (p = 0.014), awake oxygen saturation (SpO₂; p = 0.021) and awake partial pressure of oxygen (pO₂; p = 0.003); there were no significant differences in age, lung function and BMI were found for pwCF with versus without OSA (all p > 0.05). Eight pwCF (15%) had an ESS score > 10 (indicating EDS). OSA was best predicted by awake pO₂ (area under the curve [AUC] 0.66, p = 0.048), while nocturnal hypoxemia was best predicted by ppFEV₁ (AUC 0.74, p = 0.009), awake pO₂ (AUC 0.76, p = 0.006) and awake SpO₂ (AUC 0.71; p = 0.025).

Conclusion: OSA, nocturnal hypoxemia and EDS were common in adult pwCF, but no strong predictors were identified. Therefore, we suggest regular PSG and ESS scoring in adult pwCF, regardless of disease severity.