Comorbid insomnia and sleep apnea in children: a preliminary explorative study.

Insomnia and sleep-disordered breathing (SDB) are prevalent sleep disorders. These disorders can therefore be concurrently present - comorbid insomnia and sleep apnea (COMISA). The prevalence of COMISA in the paediatric age range is unclear. As such, phenotypic constructs should help better define this comorbid condition if it exists in children and improve both diagnostic sensitivity and ultimately clinical care outcomes. We aimed to evaluate the frequency of insomnia in children and adolescents referred for evaluation of sleep symptoms suggestive of SDB in one initial (Cohort#1) and verify such findings in an independent cohort (Cohort#2) using a retrospective cross-sectional approach in patients aged 9-19 years presenting at a sleep centre to be evaluated for symptoms of SDB. Cohort #1 comprised 50 consecutive children (58% males; mean [SD] age 13.6 [3.3] years; median [interquartile range, IQR] Epworth Sleepiness Scale score 10 [6-12]) who were evaluated using validated SDB and insomnia questionnaires. Cohort#2 was extracted from electronic medical records and included 384 polysomnographically evaluated children (mean [SD] age 12.9 [3.6] years; mean [SD] body mass index z score 1.27 [0.28]; median Epworth Sleepiness Scale score 9.7 [4-17]). In Cohort #1, 56% were at high risk of SDB, 36% had insomnia alone, and 18% were at high risk of COMISA. The prevalence of COMISA in Cohort #2 was 16%, 72% had SDB alone, and 12% had insomnia alone. In both cohorts, COMISA manifested as increased propensity for sleepiness and fatigue during both waking and daytime. Thus, the presence of COMISA is frequent in the paediatric age range and accompanied by a more prominent symptomatic phenotype.