Department of Psychosocial Science, University of Bergen, Bergen, Norway
Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway.
Occup Environ Med. 2020 Apr;77(4):249-255. doi: 10.1136/oemed-2019-106049. Epub 2020 Feb 4.
To investigate how a standard ceiling mounted light-emitting diode (LED)-based bright light intervention affected alertness and neurobehavioural performance during three consecutive simulated night shifts, and timing of circadian rhythm after the shifts.
Twenty seven participants (20 females, 21.4±2.1 years; mean±SD) worked three consecutive night shifts (23:00-07:00) under a full-spectrum (4000 K) bright light (900 lx) and a standard light (90 lx) condition in a counterbalanced crossover design (separated by 4 weeks). Subjective alertness (Karolinska Sleepiness Scale) and neurobehavioural performance (Psychomotor Vigilance Task and Digit Symbol Substitution Test) were assessed five times during each shift. Salivary dim-light melatonin onset (DLMO) was assessed before and after the shifts. The simulated night shifts were conducted in a laboratory while the participants slept at home.
Subjective alertness and neurobehavioural performance deteriorated during the night shifts in both light conditions. However, bright light significantly reduced alertness and performance decrements as compared with standard light. For a subset of the participants, DLMO was delayed by a mean of 3:17±0:23 (mean±SEM) hours after three night shifts in bright light and by 2:06±0:15 hours in standard light, indicating that bright light causes larger phase delay.
Bright light improved performance and alertness during simulated night shifts and improved adaptation to night work. Bright light administered by ceiling mounted LED luminaires has the potential to improve adaptation to night work and reduce the risk of accidents and injuries among night workers.
NCT03203538.
研究标准吸顶式发光二极管（LED）基明亮光干预如何在连续三个模拟夜间轮班期间影响警觉性和神经行为表现，并研究轮班后昼夜节律的时间。
27 名参与者（20 名女性，21.4±2.1 岁；均值±标准差）在全光谱（4000 K）明亮光（900 lx）和标准光（90 lx）条件下连续工作三个连续夜间轮班（23:00-07:00），采用完全交叉设计（间隔 4 周）。在每个轮班期间，五次评估主观警觉性（Karolinska 睡眠量表）和神经行为表现（精神运动警觉任务和数字符号替代测试）。在轮班前和轮班后评估唾液微光褪黑素起始（DLMO）。模拟夜间轮班在实验室进行，而参与者在家中睡觉。
在两种光照条件下，夜间轮班期间主观警觉性和神经行为表现均恶化。然而，与标准光相比，明亮光显著减少了警觉性和表现下降。对于一部分参与者，在明亮光下进行三个夜间轮班后，DLMO 延迟了平均 3:17±0:23（均值±SEM）小时，而在标准光下延迟了 2:06±0:15 小时，表明明亮光引起更大的相位延迟。
明亮光改善了模拟夜间轮班期间的表现和警觉性，并改善了对夜间工作的适应。通过吸顶式 LED 照明灯具提供的明亮光有可能改善对夜间工作的适应，并降低夜间工人事故和伤害的风险。
NCT03203538。
