Longitudinal Analysis of Sleep-disordered Breathing and Cognitive Outcomes in Children Living with Sickle Cell Anaemia

Objectives: Sleep-disordered breathing (SDB) and cognitive challenges are commonly observed in children living with sickle cell anaemia (SCA). This study investigated the longitudinal change in polysomnographic outcomes and the association with cognitive functions in children living with SCA. Method: Data from the Sleep Asthma Cohort (SAC 1, 2 and 3) included participants living with SCA (aged 4-18 years) who were initially recruited between 2006-2009, with follow-up studies conducted through until 2019. Polysomnographic indices (PSG indices), i.e., obstructive apnoea hypopnoea index (OAHI), central apnoea index (CAI), mean overnight oxygen saturation and total sleep time were assessed over two visits. Additional analyses assessed the impact of PSG indices on cognitive outcomes collected at Visit 3. Results: Ninety-two participants (91 HbSS, 1HbSβ) completed a PSG at Visit 1 and 56 participants returned for Visit 2, 40 of whom returned for the Visit 3 cognitive assessment; mean ages were 9.9 (3.8), 14.7 (3.69), and 17.7 (4.64) years, respectively. Total sleep time significantly decreased between the two visits, while overall PSG indices remained stable. Mean overnight oxygen saturation at Visit 1 significantly predicted working memory at Visit 3. In addition, CAI at Visit 2 was associated with lower scores on the verbal comprehension index and self or caregiver-reported measures of executive function. Conclusions: PSG indices did not change significantly over time; however, routine PSG screening is recommended, given the complexity of sickle pathology. Overnight oxygen saturation levels and central apnoea influence cognitive outcomes for children living with SCA.