Quality of life in clinically stable adult cystic fibrosis out-patients: associations with daytime sleepiness and sleep quality

Background: Patients with cystic fibrosis (CF) may suffer from sleep disturbances and reduced health-related quality of life (HRQoL). However, the relationships of daytime sleepiness and sleep quality to HRQoL in CF have not yet been investigated.

Patients and methods: 55 adult CF out-patients free from a pulmonary exacerbation were prospectively enrolled in this study. Questionnaires were used to assess disease-specific HRQoL (German version of the revised Cystic Fibrosis Questionnaire for adults, CFQ18 + R), daytime sleepiness (Epworth Sleepiness Scale, ESS) and sleep quality (Pittsburgh Sleep Quality Index, PSQI). 30 age- and sex-matched healthy volunteers served as a control group.

Results: The prevalence of daytime sleepiness was higher in the CF than in the control group (ESS > 10; n = 11 [20%] vs. n = 2 [6.7%]; p < 0.01) as was reduced sleep quality (PSQI > 5; n = 21 [38.2%] vs. n = 1 [3.3%]; p < 0.01). Multiple regression analysis including age, gender, body mass index, lung function and pseudomonas status showed that higher PSQI scores significantly correlated with lower CFQ18 + R scores for vitality, emotional functioning, social, role, eating disturbances and digestive symptoms.

Conclusion: In clinically stable adult CF out-patients self-reported daytime sleepiness and poor sleep quality are more common than in age and sex-matched healthy controls. In addition, impaired sleep quality is related to reduced disease-specific HRQoL in CF.