MRC Centre of Epidemiology for Child Health, UCL Institute of Child Health, London WC1N 1EH, UK.
Occup Environ Med. 2009 Dec;66(12):824-31. doi: 10.1136/oem.2008.044396. Epub 2009 Jun 14.
To examine the relationships between exposure to workplace factors (night work, extended working hours, psychosocial work stress) and cortisol secretion, and to test whether workplace factors interact, resulting in combined effects.
Multiple linear and logistic regression was used to test relationships between workplace factors and cortisol secretion in the 1958 British birth cohort at 45 years. Salivary cortisol was measured twice on the same day to capture the post-waking decline, facilitating the analysis of different cortisol patterns: (1) time 1 (T1, 45 minutes post-waking); (2) time 2 (T2, 3 h after T1); (3) average 3 h exposure from T1 to T2 cortisol; and (4) T1 to T2 change. To identify altered diurnal cortisol patterns we calculated: (1) flat T1-T2 change in cortisol; (2) top 5% T1; (3) bottom 5% T1; and (4) T1 hypo-secretion or hyper-secretion. Models were adjusted for socioeconomic position at birth and in adulthood, qualifications, marital status, dependent children, and smoking status.
25% of men and 8% of women were exposed to >1 workplace factor (night work, extended work hours, job strain). Night work was associated with a 4.28% (95% CI 1.21 to 7.45) increase in average 3 h cortisol secretion independently of job strain or work hours. Night workers not exposed to job strain had elevated T1 cortisol (5.81%, 95% CI 1.61 to 10.19), although for T2 cortisol it was night workers exposed to low job control who had elevated levels (11.72%, 95% CI 4.40 to 19.55). Men (but not women) working >48 h/week had lower average 3 h cortisol secretion (4.55%, 95% CI -8.43 to -0.50). There were no main effects for psychosocial work stress. All associations for T2 and average 3 h cortisol secretion weakened slightly after adjustment for confounding factors, but associations for T1 cortisol were unaffected by adjustment.
Our study suggests that night work in particular is associated with elevated cortisol secretion and that cortisol dysregulation may exist in subgroups with specific combinations of stressors.
研究职业暴露因素（夜班、延长工作时间、心理社会工作压力）与皮质醇分泌之间的关系，并检验职业暴露因素是否存在相互作用，从而产生联合效应。
使用多元线性和逻辑回归分析检验了 1958 年英国出生队列在 45 岁时的职业暴露因素与皮质醇分泌之间的关系。两次在同一天测量唾液皮质醇，以捕捉清醒后的下降，从而分析不同的皮质醇模式：（1）时间 1（T1，清醒后 45 分钟）；（2）时间 2（T2，T1 后 3 小时）；（3）T1 至 T2 皮质醇暴露 3 小时的平均时间；（4）T1 至 T2 的变化。为了确定改变的昼夜皮质醇模式，我们计算了：（1）皮质醇 T1-T2 变化的平坦度；（2）T1 的前 5%；（3）T1 的后 5%；（4）T1 分泌不足或分泌过多。模型根据出生时和成年时的社会经济地位、学历、婚姻状况、受抚养子女和吸烟状况进行了调整。
25%的男性和 8%的女性暴露于＞1 种职业暴露因素（夜班、延长工作时间、工作压力）。独立于工作压力或工作时间，夜班与平均 3 小时皮质醇分泌增加 4.28%（95%CI 1.21%至 7.45%）相关。不暴露于工作压力的夜班工人 T1 皮质醇升高（5.81%，95%CI 1.61%至 10.19%），而夜班且暴露于低工作控制的工人 T2 皮质醇升高（11.72%，95%CI 4.40%至 19.55%）。每周工作＞48 小时的男性（而非女性）平均 3 小时皮质醇分泌降低（4.55%，95%CI -8.43%至 -0.50%）。心理社会工作压力无主要效应。调整混杂因素后，T2 和平均 3 小时皮质醇分泌的所有关联略有减弱，但 T1 皮质醇的关联不受调整影响。
本研究表明，夜班工作尤其与皮质醇分泌升高有关，并且皮质醇失调可能存在于具有特定压力源组合的亚组中。
