夜间接触较高水平光暴露增加大学生抑郁症状风险

The mediating role of systemic inflammation in the association between bedroom light at night and new-onset depressive symptoms among Chinese young adults: A prospective cohort study

系统炎症在卧室夜间光暴露与中国青年个体新发抑郁关联中的作用：一项前瞻性队列研究

Author: Yu-xiang Xu, Min Zuo, Yi Zhou, Yu-hui Wan, Pu-yu Su, Fang-biao Tao, Ying Sun.

Source: Science of the Total Environment.

DOI: 10.1016/j.scitotenv.2024.177088.

Abstract

Background: The detrimental effects of exposure to light at night (LAN) have received increasing attention. However, the effects of LAN exposure on depressive symptoms and underlying mechanism are less explored.

Objectives: To investigate the association between LAN exposure with new-onset and trajectories of depressive symptoms, and the potential mediating role of systemic inflammation.

Methods: Baseline bedroom LAN exposure was monitored every minute for 2 consecutive nights using a portable illuminance meter. Fasting blood samples were collected at the 1-year follow-up to determine high sensitivity C-reactive protein (hs-CRP). Depressive symptoms were assessed at baseline, 1- and 2-year follow-up using the Mood and Feelings Questionnaire (MFQ).

Results: At baseline, the mean age of the 347 participants was 18.7 ± 0.8 years, and 35.2 % were men. At 2-year follow-up, the new-onset depressive symptoms were 14.7 %. Compared with low-LAN_avg (average light intensity from bedtime to rising time) intensity group (LAN_avg< 3 lx), those with high-LAN_avg intensity (LAN_avg ≥ 3 lx) were associated with an 125 % increase in risk for depressive symptoms (HR = 2.25; 95 % CI: 1.27, 4.00); Compared with short-LAN5 (duration of nighttime light intensity ≥5 lx) duration group (LAN5 < 45 min), those with long-LAN5 duration (LAN5 ≥ 45 min) were associated with an 119 % increase in risk for depressive symptoms (HR = 2.19; 95% CI: 1.18, 4.06). Participants were classified into 3 trajectory groups: consistently low, slow or rapid increase depressive symptoms; both intensity and duration of LAN exposure were associated with higher likelihood of slow or rapid increase depressive symptoms. Additionally, hs-CRP partially mediated the relationship between intensity (mediation proportion: 7.1 %) and duration (mediation proportion: 10.6 %) of LAN exposure with depressive symptoms.

Conclusion: Excessive bedroom LAN exposure is associated with increased risk of depressive symptoms among young adults, and systemic inflammation may be a partial mediator in the LAN-depressive symptoms association.

Keywords: Depressive symptoms; Developmental trajectories; Light at night; Mediation; Systemic inflammation.

摘要

背景：夜间光暴露（light at night，LAN）的有害影响越来越受到人们的关注。然而，LAN暴露对抑郁症状的影响及其潜在机制的研究较少。

目的：探讨LAN暴露与新发抑郁症状和抑郁症状轨迹的关联，以及系统炎症的潜在中介作用。

方法：基线时使用便携式照度计以1分钟为间隔连续测量2晚卧室LAN暴露。在1年随访时采集空腹血样，以检测超敏C反应蛋白（high sensitivity C-reactive protein，hs-CRP）。在基线、1年和2年随访时使用情绪和情感问卷（Mood and Feelings Questionnaire，MFQ）评估抑郁症状。

结果：在基线时，347名参与者的平均年龄为18.7±0.8岁，其中35.2%为男性。在2年的随访中，新发抑郁症状的发生率为14.7%。与低LAN_avg强度组（LAN_avg＜3 lx）相比，高LAN_avg强度（LAN_avg≥3 lx）组抑郁症状的风险增加125%（HR＝2.25；95%CI：1.27，4.00）；与短LAN5持续时长组（LAN5 < 45分钟）相比，长LAN5持续时长组（LAN5≥45分钟）抑郁症状的风险增加119%（HR＝2.19；95%CI：1.18，4.06）。参与者被分为3个抑郁症状轨迹组：持续低、缓慢或快速增加的抑郁症状；LAN暴露的强度和时长均与抑郁症状缓慢或快速增加的可能性较高有关。此外，hs-CRP部分中介了LAN暴露强度（中介比例：7.1%）和持续时长（中介比例为10.6%）与抑郁症状的关联。

结论：过多的卧室夜间光暴露与青年个体抑郁症状的风险增加有关，系统炎症可能部分中介了LAN暴露–抑郁症状的关联。

关键词：抑郁症状；发展轨迹；夜间光；中介；系统性炎症。