<b><i>Background:</i></b> Sleep-disordered breathing (SDB) and disturbed sleep are common, often underrecognized, comorbidities in people with cystic fibrosis (pwCF). <b><i>Objectives:</i></b> We studied the effect of CFTR triple combination therapy elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) on sleep in pwCF. <b><i>Method:</i></b> This was a prospective, observational sleep study in clinically stable adult pwCF. All participants underwent overnight polysomnography (PSG), before (T0) and after (T1) initiation of CFTR modulator therapy with ELX/TEZ/IVA. In addition, pulmonary function tests, calculation of BMI, and sweat chloride testing were performed. <b><i>Results:</i></b> Twenty-nine pwCF (mean age 32 ± 8 years; 15 female) participated in the study. Mean time between T0 and T1 was 194 ± 21 days. Total sleep time (TST) was 298 ± 40 min, with decreased sleep efficiency (SE) (76 ± 109) and increased sleep latency (SL) (73 ± 38 min). Sleep stages for NREM (N1–3) and REM sleep were within the normal range. Nocturnal respiratory events mainly occur during REM sleep (T0: AHI REM 8.3 ± 9.0/h; ODI REM 9.4 ± 10.6/h), whereas the overall AHI was normal (3.6 ± 3.7/h). After initiation of ELX/TEZ/IVA, we saw significant improvements in ppFEV1 (<i>p</i> &#x3c; 0.001) and BMI (<i>p</i> &#x3c; 0.001) and a reduction in sweat chloride levels (<i>p</i> &#x3c; 0.001). In parallel, there was a reduction in AHI (<i>p</i> = 0.003), ODI (<i>p</i> = 0.001), and nocturnal respiratory rate (<i>p</i> &#x3c; 0.001), both in total, REM and NREM sleep. Neither TST, SL, SE, nor sleep architecture was influenced (all <i>p</i> &#x3e; 0.05). <b><i>Conclusions:</i></b> Initiation of ELX/TEZ/IVA resulted in significant improvements in SDB in adult pwCF.

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.