Impaired declarative memory consolidation in children with REM sleep-related obstructive sleep apnea

Study objectives: We explored whether declarative memory consolidation is impaired in children with rapid eye movement sleep-related obstructive sleep apnea (REM-OSA) and investigated the correlation between memory consolidation and sleep-related respiratory parameters. Methods: Participants were children with habitual snoring aged 6-14 years and control children. Participants underwent polysomnography and declarative memory testing. Participants with snoring were categorized as primary snoring (PS), non-rapid eye movement sleep-related obstructive sleep apnea (NREM-OSA), stage-independent (SI)-OSA, and REM-OSA according to obstructive apnea-hypopnea index (OAHI), OAHI in REM sleep (OAHI(REM)), and OAHI in NREM sleep (OAHI(NREM)). Declarative memory consolidation level was assessed by recall and recognition rates. Results: There were 34 controls and 228 children with sleep-disordered breathing: 73 PS, 48 NREM-OSA, 59 SI-OSA, and 48 REM-OSA. Total arousal index was lower in the REM-OSA group than in the NREM-OSA group. In all groups, retest scores were higher than immediate test scores. Recall consolidation in PS, SI-OSA, and REM-OSA groups was lower than for controls and lower in REM-OSA than in NREM-OSA. There were no correlations between recall consolidation or recognition consolidation and OAHI, OAHI(NREM), oxygen desaturation index in REM sleep, total arousal index, or REM sleep percent. Recognition consolidation was negatively correlated with OAHI(REM). Conclusions: Memory consolidation is impaired in children with REM-OSA compared with NREM-OSA and controls. There was no significant correlation between memory consolidation and OAHI, and recognition consolidation was negatively correlated with OAHI(REM). It is important to pay attention to the OSA subtype in children.