Association between primary nocturnal enuresis and habitual snoring in children with obstructive sleep apnoea-hypopnoea syndrome

INTRODUCTION: Nocturnal enuresis (NE) and obstructive sleep apnoea-hypopnoea syndrome (OSAHS) are common problems during childhood, and population studies have reported a significant correlation between them. This study aimed to assess whether habitual snoring, mouth breathing and daytime sleepiness are associated with increased incidence of NE in children with OSAHS. MATERIAL AND METHODS: Polysomnography was performed in 42 children (66.7% males), 3.5-14.5 years old, who were evaluated for sleep-disordered breathing (SDB). RESULTS: Fourteen out of 42 children (33.3%) presented mild, 16 out of 42 (38.1%) moderate and 12 out of 42 (28.6%) severe degree of OSAHS. Apnea hypopnea index (AHI) ranged between 1.30-94.20 (10.54 ±15.67) events per hour of sleep. Nocturnal enuresis was reported in 7/42 (16.7%) of them. The main observed symptoms were snoring (90.5%), restless sleep (81%), mouth breathing (71.4%), nasal congestion (76.2%), and difficulty in arousal (52.4%). A statistically significant association was found between NE and mouth breathing (p = 0.014) or nasal congestion (p = 0.005). Children with OSAHS and NE had a higher arousal index (8.14 ±8.05) compared with OSAHS children without NE (4.61 ±7.95) (p = 0.19, z = –1.28). Snorers had higher levels of AHI (11.02 ±16.37) compared with non-snorers (6.05 ±4.81) (p = 0.33, z = –0.96), and habitually snorers (23/42, 54.76%) were at greater risk of having NE (4/23) than were non-snorers (0/4, p = 0.36). However, the prevalence of enuresis was not related to the severity of OSAHS, expressed as AHI (p = 0.70). CONCLUSIONS: Mouth breathing, nasal congestion and high threshold of arousal during sleep should be more carefully evaluated in cases of children with NE who do not respond to standard treatment and present SDB.