Comorbid Insomnia and Sleep Apnea Across the Pediatric Age: A Polysomnographic Study

Background/Objectives: Comorbid insomnia and sleep apnea (COMISA) in children is poorly documented. This study aimed to evaluate the frequency of COMISA and to explore its clinical and polysomnographic characteristics in children referred for polysomnography (PSG) for any sleep complaint. Methods: All patients with a complete insomnia sub-score on the Sleep Disturbance Scale for Children (SDSC; for children from 6 months to 16 years old) who underwent a night PSG in a pediatric sleep unit (2018–2024) were included in this retrospective study. Pathological SDSC insomnia sub-score defined insomnia and obstructive apnea-hypopnea index ≥ 2/h on PSG defined OSA. Questionnaires regarding sleepiness, depression, anxiety, and hyperactivity were also collected. Results: Children had isolated insomnia in 11.5% of cases, isolated OSA in 37.5%, and COMISA in 13.5%. Insomnia frequency was not different between patients with and those without OSA (26.5% vs. 23.5%). COMISA was more frequent in patients under 4 years old than in older ones (39.1% vs. 5.8%). No polysomnographic or clinical characteristic of COMISA was identified, except that OAHI was higher in children with isolated OSA. Patients with COMISA or isolated insomnia were more anxious than those with isolated OSA. Conclusions: Unlike in adults, the present findings do not support a mutual association between OSA and insomnia in children. OSA severity was lower in children with COMISA. Anxiety levels were higher in children with insomnia, regardless of the presence of OSA, suggesting that anxiety should be assessed in all children with OSA.