Cardiopulmonary coupling estimated sleep quality and memory in children with obstructive sleep-disordered breathing.

Objective: To investigate the association between sleep quality/stability and memory in children with sleep-disordered breathing.

Methods: Children aged 5-12 years with suspected sleep-disordered breathing who visited the Sleep Center of Beijing Children's Hospital, from June 2022 to March 2023 were enrolled. All patients underwent polysomnography (PSG) and cardiopulmonary coupling monitoring (CPC) analysis based on the photoplethysmogram, and memory tests (immediate and delayed recognition and recall) before sleep and after sleep, respectively. In the CPC analysis, high frequency coupling (HFC) as percentage of total sleep time is stable sleep. A sleep quality index (SQI) integrates HFC, sleep duration and sleep fragmentation. The correlation between memory function and sleep quality/stability was analyzed. Cyclic variation in heart rate was quantified as a sleep apnea indicator (SAI).

Results: Patients were divided into three groups based on HFC: low (<60), moderate (60-80) and high (>80). A total of 152 children were included in the study, 100 males and 52 females, with an average age of 8.2 ± 1.7 years.HFC% was negatively correlated with AHI and OAHI (r: -0.32,p: <0.01; r: -0.31, p: <0.01), while LFC% was positively correlated with AHI and OAHI (r: 0.29, p: <0.01; r: 0.28, p: <0.01). The SQI and HFC was positively correlated with the delayed recall test score(r: 0.19, p: <0.05), and with the recognition consolidation rate (r: 0.23, p: <0.05). In contrast, LFC was negatively correlated with delayed recall test score (r:0.19, p: <0.05), delayed recognition score (r:0.15,p < 0.05), and recognition consolidation rate (r:0.21, p: <0.01). SAI was negatively correlated with Recognition consolidation rate score (r: -0.17, p: <0.05).

Conclusions: Sleep stability assessed via CPC may reflect a risk biomarker for memory function in children with OSA.