Sleep findings and predictors of sleep desaturation in adult cystic fibrosis patients.

PURPOSE: Questions remain about the polysomnographic findings and the predictors for sleep desaturation in cystic fibrosis (CF) patients. Our study aimed to evaluate sleep parameters in a sample of adult CF patients comparing them with healthy controls and to determine the best predictors of sleep desaturation in CF patients with awake resting peripheral oxygen saturation (SpO(2)) ≥90%.
METHODS: In a cross-sectional study, with data collected prospectively, 51 clinically stable adult CF patients (mean age 25.1 ± 6.7 years) and 25 age-matched controls underwent an overnight polysomnography and answered sleep questionnaires. CF patients had their pulmonary function, 6-min walk test, and echocardiography assessed.
RESULTS: CF patients and control subjects had similar sleep architecture. However, CF patients had impaired subjective sleep quality and a higher arousal index than controls. The apnea-hypopnea index was similar in both groups, and only two CF patients (3.9%) fulfilled the criteria for obstructive sleep apnea syndrome. Sleep desaturation was more common in CF patients (29.4% vs 0%; p < 0.001). In a logistic regression model, we observed that awake resting SpO(2) was the single best variable associated with sleep desaturation in CF population (p < 0.001). The awake SpO(2) <94% had a sensitivity, specificity, positive and negative predictive value for sleep desaturation of, respectively, 93.3%, 100%, 100%, and 97.3%.
CONCLUSIONS: CF patients had a worse subjective sleep quality and small changes in sleep architecture. In nonhypoxic, adult CF patients, sleep desaturation is common, is not associated with obstructive sleep events, and can be accurately predicted by awake resting SpO(2) <94%.