Sleep maturation influences cognitive development of preterm toddlers

Akiko Ando,Isao Kusakawa,Tsutomu Takahashi,Rika Fukutomi,Atsushi Manabe,Takayo Nakazawa,Michio Hirata,Takashi Ikeda,Yoshihisa Oishi,Masato Mizushima,Rinshu Shimabukuro,Hiroyuki Adachi,Miwa Ozawa,Yoko Asaka,Hitoshi Yoda,Kazuo Mishima,Yuko Yoshimura,Machiko Nakagawa,Masahiro Takeshima,Keita Morioka,Kyoko Kobayashi,Yusuke Mitani,Hidenobu Ohta,Yosuke Kaneshi,Mitsuru Kikuchi,Kazutoshi Cho

doi:10.1038/s41598-021-95495-5

Abstract

Our recent study on full-term toddlers demonstrated that daytime nap properties affect the distribution ratio between nap and nighttime sleep duration in total sleep time but does not affect the overall total amount of daily sleep time. However, there is still no clear scientific consensus as to whether the ratio between naps and nighttime sleep or just daily total sleep duration itself is more important for healthy child development. In the current study, to gain an answer to this question, we examined the relationship between the sleep properties and the cognitive development of toddlers born prematurely using actigraphy and the Kyoto scale of psychological development (KSPD) test. 101 premature toddlers of approximately 1.5 years of age were recruited for the study. Actigraphy units were attached to their waist with an adjustable elastic belt for 7 consecutive days and a child sleep diary was completed by their parents. In the study, we found no significant correlation between either nap or nighttime sleep duration and cognitive development of the preterm toddlers. In contrast, we found that stable daily wake time was significantly associated with better cognitive development, suggesting that sleep regulation may contribute to the brain maturation of preterm toddlers.

Highlights

Nighttime sleep contributes more to the proper cognitive development of children or whether appropriate intellectual development depends merely on daily total sleep d uration[2,3]
Focusing on the early developmental stage of approximately 1.5 years of age, when the basic sleep structure of young children has been reported to be e stablished[1,4,5,6,7,8,9,10,11,12,13,14], we examined the effects of sleep maturation on the cognitive development of the preterm toddlers in order to find which sleep variables, such as nap, nighttime sleep, total sleep duration, or other sleep variables, contribute to their cognitive development
DQ-related factors Birth profiles Gender Birth weight Gestational age Maternal age at birth Birth order Respiratory complications Prolonged ventilation (> 7 days ) Non-significant chronic lung disease (CLD) RDS Sleep variables Daily variation in wake time Daily variation in sleep onset time Total sleep duration Sleep onset time Bed time Nighttime sleep duration Nap duration Wake time Total bed duration Sleep efficiency Sleep latency Night wakings WASO Nap end time Nap onset time Sleep arrangements Co-sleeping with parents Nighttime formula feeding Child attending kindergarten Putting children to sleep with formula Nighttime breast feeding No feeding during nighttime Child having own room r

Summary

Introduction

Nighttime sleep contributes more to the proper cognitive development of children or whether appropriate intellectual development depends merely on daily total sleep d uration[2,3]. Focusing on the early developmental stage of approximately 1.5 years of age, when the basic sleep structure of young children has been reported to be e stablished[1,4,5,6,7,8,9,10,11,12,13,14], we examined the effects of sleep maturation on the cognitive development of the preterm toddlers in order to find which sleep variables, such as nap, nighttime sleep, total sleep duration, or other sleep variables, contribute to their cognitive development

Methods

Results

Conclusion