卧室夜间光暴露延迟大学生昼夜节律时相

Exposure to real-ambient bedroom light at night delayed circadian rhythm in healthy Chinese young adults: A cross-sectional study

暴露于真实环境卧室夜间光延迟健康中国青年的昼夜节律：一项横断面研究

Authors: Yu-xiang Xu, Yan Huang, Wen-qin Ding, Yi Zhou, Yu-ting Shen, Yu-hui Wan, Pu-yu Su, Fang-biao Tao, Ying Sun

Source: Environmental Research. 2024 Mar 21; 251(Pt 2): 118657.

DOI: 10.1016/j.envres.2024.118657

Abstract

Background: Light at night (LAN)have attracted increased research attention on account of itswidespread health hazards.However, the underlying mechanism remains unknown.The objective of this study was toinvestigate the effects of real-ambient bedroom LAN exposure on circadian rhythm among young adults and potential sex differences.

Methods: Bedroom LAN exposure was measured at 60-s intervals for 2 consecutive days using a portable illuminance meter.Circadian phase was determined by the dim light melatonin onset (DLMO) time in 7 time-series saliva samples.

Results: The mean age of the 142 participants was 20.7 ± 0.8 years, and 59.9% were women.The average DLMO time was 21:00 ± 1:11 h, with men (21:19 ± 1:12 h) later than women (20:48 ± 1:07 h).Higher level of LAN intensity (LAN_avg ≥ 3lx vs. LAN_avg < 3lx) was associated with an 81.0-min later in DLMO time (95% CI: 0.99, 1.72), and longerduration of nighttime light intensity ≥ 5lx (LAN5; LAN5 ≥ 45 min vs. LAN5 < 45 min) was associated with a 51.6-min later in DLMO time (95% CI: 0.46, 1.26). In addition,the delayed effect of LAN exposure on circadian phase was more pronounced in men than in women (all P-values < 0.05).

Conclusions:Overall, bedroom LAN exposure was significantly associated with delayed circadian rhythm.Additionally, the delayed effect is more significant in men.Keeping bedroom dark at night may be a practicable option to prevent circadian disruption and associated health implications. Future studies with more advanced light measurement instrument and consensus methodology for DLMO assessment are warranted.

摘要

背景：夜间光暴露（light at night，LAN）由于其广泛的健康危害而引起越来越多的关注。然而，其潜在机制尚不清楚。本研究的目的是调查真实环境下卧室LAN暴露对青年大学生昼夜节律的影响及潜在性别差异。

方法：使用便携式照度计，以60秒为间隔连续测量2天卧室LAN暴露。通过7个唾液样本的暗光环境褪黑素开始分泌（dim light melatonin onset，DLMO）时间来确定昼夜节律时相。

结果：142名参与者的平均年龄为20.7 ± 0.8岁，女性占59.9%。平均DLMO时间为21:00 ± 1:11 h，男性（21:19 ± 1:12 h）晚于女性（20:48 ± 1:07 h）。较高水平的LAN暴露（LAN_avg ≥3lx vs.LAN_avg <3lx）与DLMO时间延迟81.0 min相关（95%CI：0.99，1.72），夜间光照强度 ≥5lx持续时长较长（LAN5 ≥ 45min vs. LAN5 <45min）与DLMO时间延迟51.6 min相关（95%CI：0.46，1.26）。此外，LAN暴露对昼夜节律的延迟效应在男性中比在女性中更加显著（所有P值均< 0.05）。

结论：总之，卧室LAN暴露与昼夜节律时相延迟显著相关。此外，延迟效应在男性中更为显著。晚上保持卧室黑暗可能是一种切实可行的选择，以防止昼夜节律紊乱及相关的健康影响。未来有必要使用更先进的光测量仪器和一致的DLMO评估方法进行研究。

Graphical Abstract