Obstructive sleep-disordered breathing, enuresis and combined disorders in children: chance or related association?

Nocturnal enuresis is usually diagnosed and treated by a primary paediatrician or family practitioner; if there is any doubt, the children may be referred to a paediatric urologist. Obstructive sleep-disordered breathing is a complex, multifactorial disorder. Adenotonsillar hypertrophy is considered an important factor associated with obstructive sleep apnoea syndrome. Enuresis and obstructive sleep-disordered breathing are both frequent problems of sleep in childhood. We conducted an electronic search in Medline, Scopus and the ISI Web of Science to look for published material and identify a putative link between nocturnal enuresis and obstructive sleep-disordered breathing. A total number of 98 documents were found, but 24 of these had to be excluded after an attentive reading of the title, abstract or full text because the information therein was not suitable for the aims of our search. Studies have found that children with obstructive sleep apnoea syndrome frequently also have nocturnal enuresis. Both disorders have an underlying sleep disturbance characterised by an altered arousal response and sleep fragmentation. The pathophysiology of enuretic events is seemingly linked to nocturnal obstructive events, causing increased intra-abdominal pressure and altered systemic blood pressure that induces natriuresis and polyuria by altering levels of antidiuretic hormone, and atrial and brain natriuretic peptides. We found 17 studies regarding the urological outcome of treatment for obstructive sleep-disordered breathing in children with enuresis. Although a vast amount of information is now available regarding the relationship between nocturnal enuresis and obstructive sleep-disordered breathing, many of the published studies were uncontrolled, retrospective or prospective cohort studies (grade C recommendation). Resolution of enuresis after medical or surgical treatment for obstructive sleep-disordered breathing has been emphasised. Consequently, symptoms such as snoring, sleep apnoeas and restless sleep should be sought for all children with enuresis. Confirmed obstructive sleep-disordered breathing should be treated promptly; subsequently, the persistence of enuresis requires treatment following the standard protocol.