Department of Epidemiology and Public Health, 1-19 Torrington Place, University College London, London WC1E 6BT, UK.
Psychoneuroendocrinology. 2013 Apr;38(4):533-41. doi: 10.1016/j.psyneuen.2012.07.012. Epub 2012 Aug 9.
We aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. Pilots sampled saliva and completed subjective mood ratings in a logbook 6 times over the day on two consecutive early shift days, two late days and two rest days. Sampling was scheduled at waking, waking+30 m, waking+2.5 h, waking+8 h, waking+12 h and bedtime. Waking time, sleep duration, sleep quality and working hours were also recorded. Cortisol responses were analysed with repeated measures analysis of variance with shift condition (early, late, rest) and sample time (1-6) as within-subject factors. Early shifts were associated with a higher cortisol increase in response to awakening (CAR(i)), a greater total cortisol output over the day (AUC(G)) and a slower rate of decline over the day than late shifts or rest days. Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days.
我们旨在采用个体内研究设计，调查早班和晚班工作如何影响日间皮质醇节律。参与者为 30 名健康的男性非吸烟飞行员，平均年龄 39.4 岁，受雇于一家短途航空公司。标准轮班模式包括 5 个早班（早上 06:00 前开始），随后是 3 个休息日，5 个晚班（中午 12:00 后开始）和 4 个休息日。飞行员在连续两天的早班、两天的晚班和两天的休息日中，每天六次在日志中记录唾液样本和主观情绪评分。采样时间安排在醒来时、醒来后 30 分钟、醒来后 2.5 小时、醒来后 8 小时、醒来后 12 小时和睡前。还记录了醒来时间、睡眠持续时间、睡眠质量和工作时间。使用重复测量方差分析，以轮班条件（早班、晚班、休息）和样本时间（1-6）作为个体内因素分析皮质醇反应。与晚班或休息日相比，早班与觉醒时皮质醇增加（CAR(i)）更大、全天皮质醇总输出（AUC(G)）更高、全天下降速度更慢有关。早班还与睡眠时间较短有关，但睡眠时间的共变并不能改变轮班对皮质醇节律的影响。与休息日相比，两种类型的工作班次都与更高的压力、疲劳和更低的幸福感有关，但对情绪评分进行统计调整并没有改变这一发现。与晚班或休息日相比，早班白天醒来时的循环皮质醇水平显著更高。
