Primary snoring in school children: prevalence and neurocognitive impairments

We aimed to investigate the prevalence of primary snoring (PS) and its association with neurocognitive impairments. Data from a community-based study in 1,114 primary school children were used to identify children who never (N = 410) or habitually snored (N = 114). In order to separate children with PS from those with upper airway resistance syndrome (UARS) or obstructive sleep apnoea (OSA), home polysomnography was conducted in all habitually snoring children. Neurocognitive impairments and poor school performance were compared between children who never snored, PS, and UARS/OSA. Polysomnography was successfully conducted in 92 habitual snorers. Of these, 69 and 23 had PS and UARS/OSA, respectively. Prevalence [95% confidence interval (95% CI)] of PS was 6.1% (4.5-7.7). Compared to children who had never snored, children with PS had more hyperactive (39% vs. 20%) and inattentive behaviour (33% vs. 11%), as well as poor school performance in mathematics (29% vs. 16%), science (23% vs. 12%), and spelling (33% vs. 20%; all P values < 0.05). PS was a significant risk factor (odds ratio; 95% CI) for hyperactive behaviour (2.8; 1.6-4.8), inattentive behaviour (4.4; 2.4-8.1), as well as daytime sleepiness (10.7; 4.0-28.4). PS was also an independent risk factor for poor school performance in mathematics (2.6; 1.2-5.8), science (3.3; 1.2-8.8), and spelling (2.5; 1.1-5.5). Odds ratios throughout were similar to the UARS/OSA group. Children with non-hypoxic, non-apnoeic PS may exhibit significant neurocognitive impairments. Consequences may be similar to those associated with UARS or OSA. If confirmed, PS is not "benign" and may require treatment.