0079 Irregular Sleep Impairs Verbal and Memory Abilities in Early Childhood

Abstract Introduction Sleep regularity, including low variability in sleep timing and duration, is one of the emerging markers of sleep health. It has been consistently linked with cognitive, emotional, and physical health, with highly variable sleep predicting negative outcomes. Yet, to date, most research regarding irregular sleep and cognitive performance has focused on adolescents and adults. The objective of this study was to examine the relationships between sleep regularity and cognitive outcomes in a sample of preschool-age children. Methods Participants were 379 preschool-age children (M=4.3 years, SD=0.78 years). Sleep was assessed using actigraphy-derived measures of regularity, including individual standard deviation of sleep midpoint and sleep duration, and social jetlag. Cognitive outcomes were measured via three separate tasks. Receptive vocabulary was assessed using the standardized scores from the Peabody Picture Vocabulary Test (PPVT-4, n=322). Visuospatial memory was measured by accuracy scores on a memory grid task (n=62). Executive attention was assessed by a preschool-adapted flanker task (n=60). Results On average, individual sleep duration varied by 59.5 min (Range=7.8-151.7 min) and sleep midpoint varied by 32.2 min (Range= 4.8-142.8 min). Additionally, the mean social jetlag was 27.6 minutes (Range= 0 - 120 min). Receptive vocabulary scores were significantly associated with variability in sleep midpoint (r(316) = -0.23, p 0.001), variability in sleep duration (r(318) = -0.21, p 0.001), and social jetlag (r(292) = -0.26, p 0.001), even after controlling for sleep duration. Performance on the visuospatial memory task was only affected by variability in sleep midpoint (r(53) = -0.3, p=0.03) and social jetlag (r(48) = -0.45, p 0.001), but not variability in sleep duration (r(53) = -0.04, p=0.75). The executive attention task was not related to any of the measures of sleep variability (all p0.05). Conclusion Findings support previous research documenting the negative impact of irregular sleep, which remains even after accounting for sleep duration. Specifically, children’s verbal and memory abilities are susceptible to these inconsistent sleep patterns. Surprisingly, however, children’s executive attention was not related to sleep variability measures, which suggests that not all cognitive outcomes are equally impacted. Support (if any) NIH R01 HL164628