ABSTRACT

Circadian misalignment remains a distinct challenge for night shift workers. Variability in individual sleep-wake/light-dark patterns might contribute to individual differences in circadian alignment in night shift workers. In this simulation study, we compared the predicted phase shift from a mathematical model of the effect of light on the human circadian pacemaker to the observed melatonin phase shift among individuals who completed one of four interventions during simulated night shift work. Two inputs to the model were used to simulate circadian phase: sleep-wake/light-dark patterns measured from a wrist monitor (Simulation 1) and sleep-wake/light-dark patterns measured from a wrist monitor enhanced by known light levels measured at the level of the eye during simulated night shifts (Simulation 2). The estimated phase shift from the model was within 2 hours of the observed phase shift in ~80% of night shift workers for both simulations; none of the model-predicted phase shifts was more than ~3 hours from the observed phase shift. Overall, the root-mean-square error between observed and predicted phase shifts was better for Simulation 1. The light input from the wrist monitor informed by actual light level measured at the eye performed better in the sub-group exposed to bright light during their night shifts. The findings from this simulation study suggest that using a mathematical model combined with sleep-wake and light exposure data from a wrist monitor can facilitate the design of shift work schedules to enhance circadian alignment, which is expected to improve sleep, alertness, and performance.

摘要

昼夜节律失调仍然是夜班工人面临的一个明显挑战。个体睡眠-觉醒/明-暗模式的差异可能导致夜班工人昼夜节律排列的个体差异。在这项模拟研究中，我们将光对人类昼夜节律起搏器影响的数学模型的预测相移与在模拟夜班工作期间完成四项干预措施之一的个体中观察到的褪黑激素相移进行了比较。模型的两个输入用于模拟昼夜节律阶段：从腕部监视器测量的睡眠-觉醒/明暗模式（模拟 1）和从腕部监视器测量的睡眠-觉醒/明暗模式，通过在模拟夜班期间眼睛的高度（模拟 2）。在两种模拟中，大约 80% 的夜班工人观察到的相移都在模型的估计相移的 2 小时内；与观察到的相移相比，模型预测的相移均不超过约 3 小时。总体而言，观察到的相移和预测的相移之间的均方根误差对于模拟 1 来说更好。根据在眼睛处测量的实际光水平通知的腕式监视器的光输入在其期间暴露于强光的子组中表现更好。夜班。这项模拟研究的结果表明，使用数学模型结合来自手腕监视器的睡眠-觉醒和光照数据可以促进轮班工作时间表的设计，以增强昼夜节律，这有望改善睡眠、警觉性和表现。