Abstract：
BACKGROUND: Sleep consolidation into nighttime is considered the primary goal of sleep development in early infants. However, factors contributing to sleep consolidation into nighttime remain unclear.
OBJECTIVE: To clarify the influences of the light environment and nighttime co-sleeping on sleep consolidation into nighttime in early infants.
METHODS: Cross-sectional study.
METHODS: Sleep-wake time and light stimulation were measured in infants for 4 consecutive days using actigraphy. The infants\' mothers were asked to complete a sleep events diary and a questionnaire about childcare, including \"co-sleeping\", defined as when the infant and mother slept on the same surface throughout the night.
METHODS: The data were analyzed with a focus on daytime and nighttime sleep parameters.
RESULTS: Daytime light stimulation reduced daytime \"active sleep\", tended to reduce daytime sleep, and increased daytime waking. Nighttime light stimulation reduced nighttime \"quiet sleep\" and nighttime sleep and increased nighttime waking. Co-sleeping reduced nighttime waking, and, as a result, nighttime sleep time and sleep efficiency increased. Co-sleeping reduced daytime sleep and tended to increase daytime waking. Consequently, co-sleeping tended to increase the ratio of nighttime sleep to daytime sleep.
CONCLUSIONS: The present findings suggest that an appropriate light environment promotes daytime waking and nighttime sleep in early infants, but it does not contribute to sleep consolidation into nighttime by itself. On the other hand, co-sleeping may promote sleep consolidation into nighttime. Therefore, further methods for safe co-sleeping need to be established while avoiding risk factors for sudden unexpected death in infancy/sudden infant death syndrome.
OBJECTIVE: To clarify the influences of the light environment and nighttime co-sleeping on sleep consolidation into nighttime in early infants.
METHODS: Cross-sectional study.
METHODS: Sleep-wake time and light stimulation were measured in infants for 4 consecutive days using actigraphy. The infants\' mothers were asked to complete a sleep events diary and a questionnaire about childcare, including \"co-sleeping\", defined as when the infant and mother slept on the same surface throughout the night.
METHODS: The data were analyzed with a focus on daytime and nighttime sleep parameters.
RESULTS: Daytime light stimulation reduced daytime \"active sleep\", tended to reduce daytime sleep, and increased daytime waking. Nighttime light stimulation reduced nighttime \"quiet sleep\" and nighttime sleep and increased nighttime waking. Co-sleeping reduced nighttime waking, and, as a result, nighttime sleep time and sleep efficiency increased. Co-sleeping reduced daytime sleep and tended to increase daytime waking. Consequently, co-sleeping tended to increase the ratio of nighttime sleep to daytime sleep.
CONCLUSIONS: The present findings suggest that an appropriate light environment promotes daytime waking and nighttime sleep in early infants, but it does not contribute to sleep consolidation into nighttime by itself. On the other hand, co-sleeping may promote sleep consolidation into nighttime. Therefore, further methods for safe co-sleeping need to be established while avoiding risk factors for sudden unexpected death in infancy/sudden infant death syndrome.
摘要：
背景：夜间睡眠巩固被认为是早期婴儿睡眠发育的主要目标。然而,导致夜间睡眠巩固的因素仍不清楚。
目的：阐明光环境和夜间共睡对早期婴儿夜间睡眠巩固的影响。
方法：横断面研究。
方法：使用肌动描记术连续4天测量婴儿的睡眠-觉醒时间和光刺激。婴儿的母亲被要求完成睡眠事件日记和关于儿童保育的问卷，包括“同睡”，定义为婴儿和母亲整夜睡在同一表面上。
方法：分析数据，重点是白天和夜间睡眠参数。
结果：白天光线刺激减少了白天的“主动睡眠”，倾向于减少白天的睡眠，增加白天的清醒。夜间光线刺激减少了夜间“安静睡眠”和夜间睡眠，增加了夜间清醒。共同睡觉减少了夜间醒来，and,因此,夜间睡眠时间和睡眠效率提高。共眠减少了白天的睡眠，并倾向于增加白天的清醒。因此,同睡倾向于增加夜间睡眠与白天睡眠的比率。
结论：目前的研究结果表明，适当的光照环境可以促进早期婴儿的白天清醒和夜间睡眠，但它本身并不有助于睡眠巩固到夜间。另一方面,共同睡眠可以促进睡眠巩固到夜间。因此,需要进一步建立安全共睡的方法,同时避免婴儿期/婴儿猝死综合征中猝死的危险因素.
目的：阐明光环境和夜间共睡对早期婴儿夜间睡眠巩固的影响。
方法：横断面研究。
方法：使用肌动描记术连续4天测量婴儿的睡眠-觉醒时间和光刺激。婴儿的母亲被要求完成睡眠事件日记和关于儿童保育的问卷，包括“同睡”，定义为婴儿和母亲整夜睡在同一表面上。
方法：分析数据，重点是白天和夜间睡眠参数。
结果：白天光线刺激减少了白天的“主动睡眠”，倾向于减少白天的睡眠，增加白天的清醒。夜间光线刺激减少了夜间“安静睡眠”和夜间睡眠，增加了夜间清醒。共同睡觉减少了夜间醒来，and,因此,夜间睡眠时间和睡眠效率提高。共眠减少了白天的睡眠，并倾向于增加白天的清醒。因此,同睡倾向于增加夜间睡眠与白天睡眠的比率。
结论：目前的研究结果表明，适当的光照环境可以促进早期婴儿的白天清醒和夜间睡眠，但它本身并不有助于睡眠巩固到夜间。另一方面,共同睡眠可以促进睡眠巩固到夜间。因此,需要进一步建立安全共睡的方法,同时避免婴儿期/婴儿猝死综合征中猝死的危险因素.
