OBJECTIVE To explore the association between vitamin D in cord blood or in venous blood and children's sleep-wake patterns at two years of age. METHODS Data were from 209 children in a birth cohort, Shanghai Sleep Birth Cohort Study (SSBC). 25-Hydroxyvitamin D (25(OH)D) was assessed in cord blood and venous blood samples at two years of age by electrochemiluminescence immunoassay. Children's sleep-wake patterns were measured with the Brief Infant Sleep Questionnaire (BISQ) and Acti-Watch at two years of age. RESULTS The prevalence of vitamin D deficiency (defined as <50 nmol/L) was 50.4% in cord blood and 28% at two years of age. The cord blood 25(OH)D level was not significantly associated with children's sleep at two years of age. Children with 25(OH)D deficiency at two years old had shorter reported and actigraphic night sleep duration (NSD) and total sleep duration (TSD) than those with normal 25(OH)D concentration. 25(OH)D level at two years old was positively associated with night and total sleep duration (βreported-NSD = 0.6, p = 0.011; βreported-TSD = 0.6, p = 0.029; βactigraphic-NSD = 0.82, p = 0.003; βactigraphic-TSD = 0.78, p = 0.006), but was not associated with daytime sleep duration. There was no significant association between 25(OH)D level with night waking duration and midpoint of sleep either measured subjectively or objectively. CONCLUSION We found that not cord blood 25(OH)D level but two-year-old 25(OH)D level was associated with children's sleep-wake patterns at two years of age. These findings suggest more attention should be paid to the assessment of 25(OH)D levels in children with short sleep duration.

中文翻译：

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25-羟基维生素D水平与儿童睡眠-觉醒模式之间的关联：一项前瞻性队列研究。

目的探讨脐带血或静脉血中维生素D与两岁儿童的睡眠-觉醒模式之间的关系。方法数据来自上海睡眠睡眠队列研究（SSBC）的出生队列中的209名儿童。通过电化学发光免疫分析法评估了两岁时脐带血和静脉血样本中的25-羟基维生素D（25（OH）D）。在2岁时，通过《简明婴儿睡眠问卷》（BISQ）和Acti-Watch来测量儿童的睡眠-觉醒模式。结果脐带血中维生素D缺乏症（定义为<50 nmol / L）的患病率为50.4％，两岁时为28％。脐血25（OH）D水平与两岁儿童的睡眠没有显着相关。两岁时患有25（OH）D缺乏症的儿童的报告和活动性夜间睡眠时间（NSD）和总睡眠时间（TSD）短于正常25（OH）D浓度的儿童。两岁时的25（OH）D水平与夜间和总睡眠时间呈正相关（β报告的NSD = 0.6，p = 0.011;β报告的TSD = 0.6，p = 0.029;β显像性NSD = 0.82，p = 0.003; βactigraphic-TSD= 0.78，p = 0.006），但与白天睡眠时间无关。主观或客观测量的25（OH）D水平与夜间醒来时间与睡眠中点之间无显着关联。结论我们发现，不是脐带血25（OH）D水平而是两岁的25（OH）D水平与两岁儿童的睡眠-觉醒模式有关。