Adherence to CPAP therapy in Down syndrome: the population-based DISCOVERY study.

BACKGROUND
Persons with Down syndrome (DS) have increased risk of obstructive sleep apnea (OSA) needing continuous positive airway pressure (CPAP), but data on the therapy and outcomes in this population are scarce. We aimed to compare patient characteristics and outcomes of CPAP treatment for OSA patients with and without DS.


METHODS
Population-based, longitudinal study on patients initiating CPAP therapy between July 2010 and March 2018 in Sweden and a population-based sex- and age-matched control group (control:case ratio 5:1), with linked data from the Swedish National Patient Registry and the Prescribed Drug Registry (DISCOVERY study cohort).


RESULTS
DS patients (n=64) had higher apnea-hypopnea index (AHI) (51.7±30.3 vs 36.8±29.1 events/hour, p<0.001), Epworth sleepiness scale (ESS) score (13.7±5.9 vs 11.0±4.9, p=0.001), rate of previous surgery of tonsils and/or adenoids (21.9% vs 8.2%, p=0.001), more thyroid replacement hormone therapy (45.3% vs 7.8%, p<0.001), but lower use of cardiovascular drugs (7.8% vs 22.3%, p=0.003) compared to controls. At follow-up after 1.3±0.9 years, there were no differences in nocturnal CPAP usage time (5.6±2.4 vs 5.5±2.0 hours, p=0.77), CPAP adherence ≥4 hours/night (62% vs 65%, p=0.93), or improvement in ESS score (-5.4±6.8 vs -5.0±2.0, p=0.84) between DS and non-DS patients.


CONCLUSION
OSA severity was substantially higher in DS patients despite an increased rate of tonsil surgery. Treatment outcomes in terms of adherence and improved daytime sleepiness were comparable between groups underlining the importance of both OSA diagnosis and treatment in DS patients.