Sleep-related symptoms and sleep-disordered breathing in adult Pompe disease

Respiratory muscle weakness is the major cause of early death in patients with adult Pompe disease. It first manifests as nocturnal hypercapnia, eventually leading to sleep disruption. Sleep-related symptoms along with motor performance, forced vital capacity (FVC) and respiratory symptoms were investigated in 65 adult patients with Pompe disease.

Patients answered the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale, the Fatigue Severity Scale, the Rotterdam Nine-item Handicap Scale, the SF-36 health-related quality of life questionnaire, and a respiratory symptom questionnaire. In all patients, the 6-min walk test was performed and FVC was obtained. Polysomnography and oxycapnometry results were available in 31 patients.

Sixty patients received enzyme replacement therapy, and 32 individuals were on home ventilatory support. Reduced sleep quality was highly prevalent (PSQI > 5; 43.1%) and correlated with both excessive daytime sleepiness (Epworth Sleepiness Scale > 10; 24.6%) and fatigue (Fatigue Severity Scale > 4; 72.3%). The SF-36 health-related quality of life questionnaire was reduced in the physical domains, and was inversely correlated with sleep quality, FVC and motor performance. In 11 out of 17 non-ventilated patients with polysomnography records, sleep-disordered breathing was present, and duration of nocturnal oxygen desaturation (SaO2 < 90%) was significantly correlated to the PSQI global score.

In adult Pompe disease, sleep disturbances are a common cause of excessive daytime sleepiness and fatigue. Sleep-related symptoms may be indicative of respiratory muscle weakness and should give rise to further work-up of sleep-disordered breathing.