Predicting Sleep-Disordered Breathing in Patients With Cystic Fibrosis

To examine predictors of sleep-disordered breathing in patients with cystic fibrosis (CF) and moderate-to-severe lung disease using a comprehensive evaluation of both sleep and daytime function. Cross-sectional analysis of sleep studies, lung function, respiratory muscle strength, and evening and morning arterial blood gas measurements in patients with stable CF. A questionnaire addressing sleep quality was administered. Forward stepwise regression analysis was used to identify the parameters that best predict sleep-related desaturation, hypercapnia, and respiratory disturbance. Sleep investigation unit and lung function laboratory. Thirty-two patients with CF and FEV1 < 65% predicted, in stable clinical condition. Patients were aged 27 ± 8 years (mean ± 1 SD) with FEV1 of 36 ± 10% predicted, evening Pao2 of 68 ± 8 mm Hg, and Paco2 of 43 ± 5 mm Hg. Evening Pao2 (p < 0.0001) and morning Paco2 (p < 0.01) were predictive of the average minimum oxyhemoglobin saturation per 30-s epoch of sleep (r2 = 0.74; p < 0.0001). Evening Pao2 (p < 0.001) was predictive of the rise in transcutaneous carbon dioxide (Tcco2) seen from non-rapid eye movement (NREM) to rapid eye movement (REM) sleep (r2 = 0.37; p < 0.001). In addition, there was some relationship between expiratory respiratory muscle strength and the REM respiratory disturbance index (r2 = 0.22; p < 0.01). Evening Pao2 was found to contribute significantly to the ability to predict both sleep-related desaturation and the rise in Tcco2 from NREM sleep to REM sleep in this subgroup of patients with CF.