Persson Roger, Garde Anne Helene, Hansen Ase Marie, Osterberg Kai, Larsson Britt, Orbaek Palle, Karlson Björn
National Research Centre for the Working Environment, Copenhagen, Denmark.
Chronobiol Int. 2008 Nov;25(6):923-37. doi: 10.1080/07420520802553648.
Measurement of cortisol concentration can contribute important information about an individual's ability to adjust to various environmental demands of both physical and psychosocial origin. However, one uncertainty that affects the possibilities of correctly interpreting and designing field studies is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month-to-month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time-of-day (4 levels) as categorical predictors. Cortisol concentrations were analyzed on a log scale. The diurnal pattern of cortisol was similar across months (interaction between month and time of day: p>0.4). The main effects of month and time-of-day were statistically significant (p<0.001). Highest concentrations were observed in February, March, and April, and lowest concentrations were observed in July and August. There were no statistically significant effects in any of the other measures, or between men and women. In conclusion, a seasonal variation in salivary cortisol concentrations was detected in an occupationally active population. Thus, seasonal variation needs to be taken into account when designing and evaluating field studies and interventions and when making comparisons across studies.
测量皮质醇浓度有助于获取有关个体适应身体和心理社会等各种环境需求能力的重要信息。然而，影响正确解释和设计现场研究可能性的一个不确定因素是缺乏关于季节变化对皮质醇排泄影响的观察。因此，对一组年龄在32至61岁、从事体力工作的24名健康男性和女性进行了研究，观察其昼夜皮质醇浓度、觉醒皮质醇反应（ACR）、早晨最高浓度以及白天下降情况的逐月变化。在连续12个月的一个工作日里，参与者在四个时间点采集唾液以测定皮质醇：觉醒时、30分钟后、8小时后以及21:00时。数据采用重复测量设计进行分析，将月份（12个水平）和一天中的时间（4个水平）作为分类预测变量。皮质醇浓度以对数尺度进行分析。皮质醇的昼夜模式在各月间相似（月份与一天中时间的交互作用：p>0.4）。月份和一天中时间的主效应具有统计学意义（p<0.001）。在2月、3月和4月观察到最高浓度，在7月和8月观察到最低浓度。在任何其他测量指标中，以及在男性和女性之间均未观察到统计学上的显著差异。总之，在从事职业活动的人群中检测到唾液皮质醇浓度存在季节性变化。因此，在设计和评估现场研究及干预措施以及进行跨研究比较时，需要考虑季节性变化。
