Nocturnal hypoventilation in children with obesity

Sleep-disordered breathing (SDB) is an increasingly recognized co-morbidity in childhood obesity. SDB may contribute to the excessive weight gain; however, diagnosis and treatment strategies are not well-defined during childhood. Most pediatric studies focus solely on obstructive sleep apnea (OSA), although hypoventilation may play a separate but pivotal role in the course of the condition. This study aimed to explore the role of transcutaneous carbon-dioxide monitoring (tcCO₂) as a part of the polysomnographic assessment (PSG) in identifying nocturnal hypoventilation and non-invasive ventilation (NIV) need for overweight and obese children with SDB.

In this retrospective study clinical, PSG and tcCO₂ data of children with overweight and obesity (BMI Z-score ≥1; 5-18 yrs) were collected between 2021 and 2024. PSG recordings, including tcCO2 monitoring, were analyzed according to current guideline. The frequency of OSA, nocturnal hypoventilation and obesity hypoventilation syndrome (OHS), along with the need for long-term NIV treatment were determined.

Out of 41 children involved, sixteen (39 %) had mild, seven (17 %) had moderate and ten (24 %) had severe OSA. Twenty-three children met the criteria for nocturnal hypoventilation. In four patients hypoventilation was present without OSA. Seventeen children were diagnosed with OHS; NIV was initiated in 18 children.

SDB is a possible consequence of childhood obesity and hypoventilation can be present without OSA. As our results suggest, concurrent continuous monitoring of tcCO₂ can identify hypoventilation, which can be present without severe OSA. TcCO₂-assisted polysomnography may be essential for identifying the need for NIV and for preventing adverse outcomes.