Age-dependent dissociation between sleep-disordered breathing severity and ventilatory impairment in children with Prader-Willi syndrome.

Introduction: Sleep-disordered breathing (SDB) is highly prevalent in children with Prader-Willi syndrome (PWS), encompassing central, obstructive, and ventilatory abnormalities. However, its longitudinal evolution remains incompletely understood. Methods: We conducted a retrospective longitudinal study of children with genetically confirmed PWS who underwent serial respiratory polygraphy with concurrent transcutaneous carbon dioxide (TcCO₂) monitoring. Clinical characteristics, therapeutic interventions, and longitudinal respiratory parameters were analyzed using linear mixed-effects models. Results: Twenty-nine children were included. SDB demonstrated an age-dependent pattern, with central respiratory abnormalities predominating in early childhood and obstructive events becoming more prominent during preschool and school age. In contrast, nocturnal ventilatory impairment was mainly observed in older children and adolescents. Clinical symptoms were independently associated with ENT intervention, whereas higher body mass index was associated with a greater likelihood of requiring non-invasive ventilation, supporting distinct obstructive and ventilatory phenotypes. Although unadjusted analyses suggested increasing TcCO₂ values with age, adjusted mixed-effects models indicated that this relationship was largely explained by obesity and treatment-related factors. Conclusions: SDB in children with PWS appears to represent an evolving continuum of central, obstructive, and ventilatory abnormalities. Conventional apnea indices alone may not adequately reflect ventilatory impairment, supporting longitudinal assessment of nocturnal gas exchange in addition to standard respiratory event indices.