Introduction
Given the well-recognized coexistence of sleep-disordered breathing and
obstructive lung diseases such as COPD and asthma , it is not surprising
that sleep-disordered breathing also coexists with cystic fibrosis
(CF).1-4 Sleep architecture, the cyclical pattern of
sleep between different sleep stages, is similar in CF patients compared
to normal controls; however, CF patients have impaired subjective sleep
quality.5 Poor sleep quality can be due to upper
airway disease such as sinus disease, structural lung disease, chronic
cough, use of medications including opioids, and the prevalence of
sleep-disordered breathing.6 Sleep-disordered
breathing encompasses a broad spectrum of respiratory abnormalities
during sleep, ranging from primary snoring, respiratory event related
arousals (RERAs), nocturnal hypoxia, obstructive sleep apnea (OSA), and
hypoventilation. Primary snoring does not have physiological
consequences; however, other respiratory abnormalities during sleep,
especially OSA, can have significant deleterious effects.
Untreated sleep-disordered breathing can adversely affect outcomes in
patients with chronic lung disease7, and therefore it
is essential that CF clinicians expeditiously screen, diagnose, and
treat sleep-disordered breathing in the CF population. In this review,
we focus on three clinically relevant categories of sleep-disordered
breathing: nocturnal hypoxemia, obstructive sleep apnea, and nocturnal
hypoventilation.8 We will also discuss proposed areas
for future research, and suggest key practical take home points for the
non- sleep trained CF clinician.
We acknowledge that other sleep disorders such as insomnia, periodic leg
movements and circadian rhythm disturbances are prevalent in individuals
with CF, but these are outside the scope of this review. In addition, we
will not be covering respiratory related arousals and central sleep
apnea, as little is known about these conditions as it specifically
applies to the CF population9.