光线对情绪有强大的影响,睡眠,和昼夜节律系统。人类在白天和黑夜有明显区别的环境中进化,但是我们的现代环境已经模糊了这种区别。夜间光照的负面影响已经得到了很好的表征。白天曝光的重要性还没有得到很好的表征。在这里,我们研究了在白天户外光线下花费的时间与情绪的横截面和纵向关联,睡眠,和昼夜节律相关的结果。
参与者来自英国生物银行队列,一项针对英国成年人的大型研究(n=502,000;37-73岁;54%的女性)。
UKBiobank参与者报告说,每天在户外花费2.5个白天小时(IQR=1.5-3.5小时)的中位数。白天在户外度过的每一小时与终生重度抑郁症的几率较低相关(95%CIOR:0.92-0.98),抗抑郁药的使用(OR:0.92-0.98),不频繁的快感缺失(OR:0.93-0.96)和情绪低落(OR:0.87-0.90),更高的幸福感(OR:1.41-1.48)和更低的神经质(发生率,IRR:0.95-0.96),独立于人口,生活方式,和就业协变量。此外,每小时的白天光线与更容易起床相关(OR:1.46-1.49),疲劳频率较低(OR:0.80-0.82),失眠症状较少(OR:0.94-0.97),和较早的时间型(调整后的比值比;OR:0.75-0.77)。自回归交叉滞后(ARCL)模型用于检查基线时在室外光线下花费的时间与后期情绪的纵向关联,在时间点2报告的睡眠和昼夜节律相关结局。总的来说,纵向关联支持横截面发现,虽然通常具有较小的效果大小。
需要进行未来的研究,以检查眼睛水平的白天光暴露强度。
我们的研究结果表明,白天光线暴露不足是情绪的重要环境风险因素,睡眠,和昼夜节律相关的结果。
Light has powerful effects on mood, sleep, and the circadian system. Humans evolved in an environment with a clear distinction between day and night, but our modern environments have blurred this distinction. Negative effects of light exposure at night have been well characterized. The importance of daytime light exposure has been less well characterized. Here we examine the cross-sectional and longitudinal associations of time spent in daytime outdoor light with mood, sleep, and circadian-related outcomes.
Participants were drawn from the UK Biobank cohort, a large
study of UK adults (n = 502,000; 37-73 years old; 54% women).
UK Biobank participants reported spending a median of 2.5
daylight hours (IQR = 1.5-3.5 h) outdoors per day. Each additional hour spent outdoors during the day was associated with lower odds of lifetime major depressive disorder (95% CI OR:0.92-0.98), antidepressant usage (OR:0.92-0.98), less frequent anhedonia (OR:0.93-0.96) and low mood (OR:0.87-0.90), greater happiness (OR:1.41-1.48) and lower neuroticism (incident rate ratio, IRR:0.95-0.96), independent of demographic, lifestyle, and employment covariates. In addition, each hour of daytime light was associated with greater ease of getting up (OR:1.46-1.49), less frequent tiredness (OR:0.80-0.82), fewer insomnia symptoms (OR:0.94-0.97), and earlier chronotype (adjusted odds ratio; OR:0.75-0.77). Auto-Regressive Cross-Lagged (ARCL) models were used to examine the longitudinal association of time spent in outdoor light at baseline with later mood-, sleep- and circadian-related outcomes reported at time point 2. Overall, longitudinal associations support cross-sectional findings, though generally with smaller effect sizes.
Future studies that examine the intensity of daytime light exposure at the ocular level are needed.
Our findings suggest that low daytime light exposure is an important environmental risk factor for mood, sleep, and circadian-related outcomes.