Interplay of Weight Status and Sleep Autonomic Function in Mediating and Moderating the Link Between Disease Severity...

Obstructive sleep apnoea (OSA) in children is associated with numerous adverse outcomes, including elevated blood pressure. While the associations between OSA, obesity, and autonomic dysfunction are recognised, the precise mechanisms linking these factors and their relationship with elevated blood pressure in children remain unclear.

This retrospective case series included 76 children with OSA. The relationships between night-time systolic and diastolic blood pressures, body mass index, and clinical, polysomnographic, and sleep heart rate variability variables were investigated. Mediation and moderation analyses were performed.

Correlation analyses revealed significant associations between both systolic and diastolic blood pressures with body mass index, age, sex, adenoidal-nasopharyngeal ratio, apnoea-hypopnoea index, and sleep low frequency/high frequency (LF/HF) ratio. In multivariable linear regression models, body mass index, adenoidal-nasopharyngeal ratio, and LF/HF ratio were independently associated with systolic blood pressure, while body mass index and adenoidal-nasopharyngeal ratio were independently associated with diastolic blood pressure. Mediation and moderation analyses identified a conceptual mediation with a moderated direct path model in which body mass index mediated, and the LF/HF ratio moderated, the relationship between apnoea-hypopnoea index and systolic blood pressure. Additionally, children with concomitant OSA and attention deficit hyperactivity disorder had a significantly higher LF/HF ratio than those with OSA alone.

In children with OSA, the relationship between apnoea-hypopnoea index and systolic blood pressure was mediated by weight status and modulated by sleep sympathovagal balance. Children with OSA and attention deficit hyperactivity disorder exhibited greater disturbances in sympathovagal balance. Further research is warranted to explore these associations.