Obstructive Sleep Apnea (OSA)
In the spectrum ranging from snoring to respiratory event related
arousals (RERAs) to OSA, OSA is the most pathologic. In a study with 63
children and adolescents with CF between the ages of 2 and 14 years, the
prevalence of polysomnogram-identified OSA has been reported to be
55.6%.47 Similarly, a study by Spicuzza et al.
demonstrated that 70% of the 40 children between the age of 6 months
and 11 years with stable CF had OSA.13 Of note, in
children without underlying lung disease, the prevalence of OSA has been
reported to be 1% to 4%.8 Although both groups of
children with OSA share common factors such as adenotonsillar
hypertrophy, craniofacial abnormalities such as micrognathia or
midfacial hypoplasia, the children with CF have increased chronic
rhinosinusitis (CRS).8,47 Increased respiratory
resistance and hypoventilation related to acute and chronic inflammation
has been cited as a potential mechanism for upper airway
obstruction.48
To our knowledge, there are no studies specifically examining the
relationship between CF related CRS and OSA, however the literature
surrounding non-CF CRS and OSA can be extrapolated to CF related CRS.
CRS has been shown to be strongly associated with poor subjective sleep
quality and unequivocally associated with OSA.49-51With respect to the latter, Jiang et al found that up to 64.7% of adult
patients with CRS had comorbid OSA on polysomnography
(PSG).49 In contrast, Alt et al identified OSA in only
15% of adult patients with CRS.50 Mahdavinia et al.
examined how CRS affects polysomnography findings in patients with
comorbid OSA. They compared patients with both CRS and OSA to patients
with OSA and without CRS, and found that the AHI (Apnea-Hypopnea Index
)between the two groups was similar suggesting that CRS may not
significantly impact AHI.52 The effect of CRS, if any,
on OSA has been theorized to be related to increased nasal airway
resistance and sequelae of chronic inflammation.53 It
has also been posited that chronic post-nasal drainage associated with
sino-nasal inflammation can induce inflammatory, obstructive changes in
the upper airway including the soft palate and
uvula.52
OSA is not known to be as common in adults as in the pediatric
population with CF. In a cross-sectional study with 51 stable CF adults
(mean age 25.1 years), only two CF patients (3.9%) met the standard
criteria for OSA.5 One major study in a non-CF
population has reported prevalence rates in men and women as high as
24% and 9% respectively.8 Studies with adult CF
patients have been limited due to the sample size, lack of diversity,
lack of an older age group which potentially underestimates the
prevalence.5