Sleep disordered breathing and airway disease in primary ciliary dyskinesia

Background and objective: Sleep-disordered breathing (SDB) may develop in primary ciliary dyskinesia (PCD), leading to these diseases worsening one another. Methods: Sixteen stable PCD patients (4.9-17.2 years) and 42 controls underwent overnight respiratory polysomnography (rPSG) and Sleep Disturbances Scale for Children (SDSC). In PCD we assessed nasal endoscopy, pulmonary function tests and chest highresolution computed tomography (HRCT). Results: Compared with controls, PCD had higher obstructive apnoea (4.7 vs 0.2, P < 0.001), central apnoea (0.8 vs 0.2, P < 0.001), hypopnoea (1.8 vs 0.2, P < 0.001), apnoea-hypopnoea (7.8 vs 0.6, P < 0.001), oxygen desaturation indexes (ODI; 0.7 vs 0.2, P = 0.002), and mean oxygen desaturation (4% vs 1%, P < 0.001), while mean and nadir oxygen saturation (97.1% vs 98.1, P < 0.001) (93% vs 97.2%, P < 0.001) were lower, respectively. In PCD, SDSC was unrelated to rPSG (P > 0.05), with total score and subscores of disorders in initiating and maintaining sleep, and sleep- wake transition lower than controls. PCD patients had chronic rhinosinusitis (100%) and adenoidal hypertrophy (50%). Total HRCT score was 7 (range 0-14). ODI correlated with functional residual capacity (r = 0.8, P = 0.02), total HRCT (r = 0.6, P = 0.03) and peribronchial thickening scores (r = 0.7, P = 0.02). Oxygen saturation was associated with bronchiectasis severity score (r = -0.6, P = 0.02). Conclusions: PCD's parents may underestimate SDB. As nocturnal desaturation is associated with lung function and structure abnormalities, SDB may signifi- cantly contribute to pulmonary morbidity.