OBJECTIVE: To determine the prevalence of nocturnal hypoxemia and its association with
pulmonary function, nutritional status, sleep macrostructure, and
obstructive respiratory events during sleep in a population of clinically
stable children and adolescents with cystic fibrosis (CF). METHODS: This was a cross-sectional study involving 67 children and adolescents with
CF between 2 and 14 years of age. All of the participants underwent
polysomnography, and SpO2 was measured by pulse oximetry. We also
evaluated the Shwachman-Kulczycki (S-K) scores, spirometry findings, and
nutritional status of the patients. RESULTS: The study involved 67 patients. The mean age of the patients was 8 years.
The S-K scores differed significantly between the patients with and without
nocturnal hypoxemia, which was defined as an SpO2 < 90% for
more than 5% of the total sleep time (73.75 ± 6.29 vs. 86.38 ± 8.70; p
< 0.01). Nocturnal hypoxemia correlated with the severity of lung
disease, FEV1 (rs = −0.42; p = 0.01), FVC (rs
= −0.46; p = 0.01), microarousal index (rs = 0.32; p =
0.01), and apnea-hypopnea index (rs = 0.56; p = 0.01). CONCLUSIONS: In this sample of patients with CF and mild-to-moderate lung disease,
nocturnal oxygenation correlated with the S-K score, spirometry variables,
sleep macrostructure variables, and the apnea-hypopnea index.