Long-Term Improvements in Sleep and Respiratory Parameters in Preschool Children Following Treatment of Sleep Disordered Breathing.

STUDY OBJECTIVE: Sleep disordered breathing (SDB) in preschool-aged children is common, but long-term outcomes have not been investigated. We aimed to compare sleep and respiratory parameters in preschool children to examine the effects of treatment or non-treatment after 3 years. METHODS: Children (3-5 years) diagnosed with SDB (n = 45) and non-snoring controls (n = 30) returned for repeat overnight polysomnography (39% of original cohort), 3 years following baseline polysomnography. Children with SDB were grouped according to whether they had received treatment or not. SDB resolution was defined as an obstructive apnea hypopnea index (OAHI) ≤ 1 event/h, no snoring detected on polysomnography and habitual snoring not indicated by parents on questionnaire. RESULTS: Fifty-one percent (n = 23) of the children with SDB were treated. Overall, SDB resolved in 49% (n = 22), either spontaneously (n = 8) or with treatment (n = 14). SDB remained unresolved in 39% (n = 9) of those treated and 64% (n = 14) of the children who were untreated. Two of the non-snoring controls developed SDB at follow-up. The treated group had significantly lower OAHI (p < 0.01), respiratory disturbance index (p < 0.001), total arousal and respiratory arousal indices (p < 0.01 for both) at follow-up compared with baseline. There were no differences between studies for the untreated group. CONCLUSIONS: Although treatment resulted in an improvement in indices related to SDB severity, 39% had SDB 3 years following diagnosis. These findings highlight that parents should be made aware of the possibility that SDB may persist or recur several years after treatment. This is relevant regardless of the severity of SDB at baseline and the treatment given.

Seasonal variability in paediatric obstructive sleep apnoea.

BACKGROUND: Allergy and respiratory viral infection may contribute to the pathogenesis of sleep disordered breathing (SDB) through promoting adenotonsillar growth. We investigated the seasonal variation of SDB in children by analysing the change in the obstructive apnoea hypopnoea index (OAHI) throughout the year. PARTICIPANTS: 257 3-12-year-old children referred for assessment of SDB underwent overnight polysomnography (PSG). RESULTS: Mean seasonal OAHI was significantly higher in winter (5.1±0.8 events/h) and spring (4.6±0.9 events/h) compared with autumn (2.4±0.8 events/h; p<0.01 and p<0.05, respectively) and summer (2.0±0.5 events/h; p<0.05 for both). There were no differences in OAHI between summer and the other seasons or between winter and spring. CONCLUSIONS: We identified more severe obstructive sleep apnoea in clinically referred children during winter and spring and suggest that inflammation from respiratory viruses may contribute to adenotonsillar hypertrophy, worsening airway obstruction. Clinicians should take season into account when interpreting PSG results.