Association between primary nocturnal enuresis and habitual snoring in children with obstructive sleep apnoea-hypopnoea syndrome dren without sleep-disordered breathing (11.3% vs. 6.3%). However, a recent large cohort of 7.5-year olds found that of the 15.5% children who wet the bed, the majority wet only once or less a week, with a rela- tively small number (2.6%) meeting the DSM-IV (Ame- rican Psychiatric Association 1995) criteria of noctur- nal enuresis, wetting at least twice a week [4]. There was evidence for an association between SDB and NE in a large Greek community sample of children aged 5-14 years [26], whereas children with habitual snoring were 4 times more likely than those who did not regularly snore to have primary enuresis. It is known that snoring symptomatology alone correlates poorly with objective (polysomnographic) findings [27]. In our study there was also an associa- tion between the presence of snoring and the severity of OSAHS, although without statistical significance (p > 0.05). No statistically significant association was also recorded between the degree of OSAHS expres- sed as AHI and the presence of NE (p = 0.70). Howe- ver, no population-based studies have assessed the association between primary nocturnal enuresis and snoring while considering the effect of the subjects’ age and sex. Nocturnal enuresis is also more common in the habitual snoring group [13], as in our study where 7/38 children who snore had NE (18.42%), while none of the non-snorers had NE (4/4, 100%), and all belong to the habitual snorers group (more than 4 times per week). Based on 95% CI shown in Table III there were statistically significant associa- tions between NE and snoring almost every night (OD: 1.33, 95% CI: 1.05-1.68). A number of polysomnographic studies (PSG) have compared patients with NE to controls and in gene- ral found no evidence of SDB, but did note that enu- retic patients had a high arousal threshold [13]. It has been postulated that nocturnal enuresis in people with airway obstruction results from increased pro- duction of atrial natriuretic peptide, which increases the arousal threshold in sleep [6]. Moreover, based on the article of T. Nevéus, enuresis is not just a nocturnal problem but a disorder of sleep. The high arousal threshold is one of three major pathogenetic factors in enuresis – nocturnal polyuria and detrusor hyper- activity being the other two [28]. In our study, chil- dren with NE had a higher arousal index per hour of TST (8.14 ±8.05) compared with children with OSAHS who did not present NE (4.61 ±7.95) (p = 0.19). The relationship between sleep EEG and the enu- retic event cannot safely be assumed to be the same in these different subgroups of children, because it is quite possible that sleep mechanisms might inter- act with urine production and/or bladder function [23]. Children with OSA have fewer EEG arousals compa- red to adults with OSA, and thus are able to better preserve sleep architecture. This observation may reflect increased sleep pressure leading to decreased arousability in the child. As such, the decreased arou- sability may contribute to the increased frequency of nocturnal enuresis seen in paediatric OSA [7]. The most common aetiology of OSAHS in children is hypertrophy of adenoids and/or tonsils. In these cases, surgical removal is the treatment of choice and can also affect bedwetting. For example, Weiss- bach et al. [29] documented significant reductions or elimination of nocturnal enuresis in children who had surgical repair for upper airway obstruction. Similar results were reported by Firoozi et al. [2] for children who underwent surgical resection of hyper- trophic tonsils and adenoids. In our study, there was a positive correlation between the severity of OSAHS expressed with AHI and the tonsillar size (r = 0.20, p = 0.23), according to the Mallampati classification [15]. This observation is in agreement with our find- ings that the most important symptoms that are correlated with the presence of NE were mouth brea- thing (p = 0.01, OD: 10, 95% CI: 1.59-62.78) and nasal congestion (p = 0.005, OD: 15, 95% CI: 2.25-99.63), which are symptoms that are correlated with hyper- trophic tonsils and adenoids and OSAHS [30]. Primary nocturnal enuresis is usually more com- mon in boys than in girls, with a 3 : 1 gender ratio [31, 32]. In published reports, the prevalence of bed- wetting was greater in populations with low socio- economic status, and declined with increasing age [4, 31], as in our study where NE was not recorded in children older than 10 years of age and its frequency was reduced after 8 years of age (5/42 patients [11.8%] in the age group 2-8 years old and 2/42 pa- tients [4.8%] in the age group > 8 years old). In our study, there was a predominance of female sex con- cerning the appearance of nocturnal enuresis in chil- dren with OSAHS. In particular, there were 3/28 males (10.71%) with OSAHS (3/42 patients, 7.14% of the study population) and 4/14 females (28.57%) with OSAHS (4/42 patients, 9.5% of the study population) who presented with nocturnal enuresis (p = 0.14) (Table II). There were significantly higher levels of reports of daytime sleepiness and behavioural problems in all NE children [13]. In our study, behaviour problems were reported in 9.5% of children with OSAHS, but none presented NE. Hyper-motility was recorded in 26.2% of patients with OSAHS (11/42), aggressive- ness in 2.4% (1/42), attention deficit in 11.9% (5/42) and difficulty in arousal in 47.6% of patients with OSAHS (20/42). Aggressive behaviour or attention deficit disorder has not been reported for any of the patients with OSAHS and NE. Only 2/11 (18.18%) with hyper-motility also had NE (p = 1.00) and 2/20 chil- dren with difficulty in arousal had NE (p = 0.41). According to 95% CI shown in Table III, behaviour pro- blems and attention deficit disorders did not appear to be statistically significant factors that were corre- lated with the presence of NE in children with OSAHS. We should also mention that 95% CI were quoted because clinically important outcomes may fail to Arch Med Sci 3, June / 2012 525