Significance of Sleep-disordered breathing in the CF population
Insufficient sleep, which can be a consequence of sleep-disordered
breathing, has been recognized as a risk factor for mortality in young
adults and is of high concern10. Sleep complaints
occur in 40% of children with CF, with 70% reporting daytime
sleepiness11. It is important to note that neither
malnutrition nor respiratory muscle weakness are necessary to develop
hypoxemia or hypercapnia during sleep, putting a larger portion of the
CF population at risk for sleep-disordered breathing than was originally
believed 12. Obstructive sleep apnea in particular is
noted to have a high prevalence in CF children, and OSA can lead to
deteriorating school performance, failure to thrive, and worsening lung
function13. Besides, sleep-disordered breathing in
children with chronic pulmonary diseases including CF can lead to
neurocognitive effects that hamper development s14.
Therefore, it is important that CF pediatric providers are aware of the
impact of sleep-disordered breathing in their patients.
As the CF population overall has improved longevity, medical conditions
that are associated with sleep-disordered breathing such as obesity,
diabetes, and cardiovascular diseases are
emerging.15-18 It is
important to acknowledge that the adult population with CF has exceeded
the pediatric population since 2015, and increased age is known to be a
major risk factors for the development of sleep-disordered
breathing.19,20 Improvement in genetic diagnosis of CF
has also led to milder phenotypes of CF being recognized in later life
,21 when patients are at risk for other age related
comorbidities. Also, as this population gains weight, the risk for OSA
in particular is increased. A study by Peppard et al. has shown that a
10% increase in weight increases the risk of OSA
6-fold.20 Cardiovascular complications
such as hypertension, coronary artery disease, and stroke have been
described in adults with OSA22, 23,24. Autonomic dysfunction in OSA is associated with
impaired glucose tolerance25, and the implications
of the development of diabetes is well known to CF clinicians. In
addition, fragmented sleep caused by sleep-disordered breathing is known
to cause fatigue, which is highly prevalent in CF and negatively
associated with wellbeing and emotional health 26. The
fragmented sleep that leads to fatigue is a result of frequent nocturnal
awakenings. It has been shown that forced expiratory volume in 1 second
(FEV1) inversely correlates with the number of nocturnal
awakenings, which means there is more fragmented sleep as lung function
declines.27
Without question, the above concerns highlight that CF clinicians need
to be looking for and treating sleep-disordered breathing in these
patients.