Unit of Public Health and Preventive Medicine, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
Occupational Stress Research Group, National Institute of Occupational Safety and Health, 6-21-1 Nagao, Tama-ku, Kawasaki-shi, Kanagawa 214-8585, Japan.
Psychoneuroendocrinology. 2020 Jun;116:104650. doi: 10.1016/j.psyneuen.2020.104650. Epub 2020 Mar 12.
This study aimed to validate the association between hair cortisol and 30-day integrated salivary cortisol levels. Additionally, the intra-individual stability of the hair cortisol and the association between hair cortisol and salivary cortisol in several time domains were systematically explored. Twenty-four adults (15 men and 9 women, mean age: 22.7 ± 2.8 years) were asked to collect three saliva samples per day for 30 days, immediately after awakening (time 1), 30 min after awakening (time 2), and at bedtime (time 3). The hair sample was taken from the posterior vertex as close as possible to the scalp at the end of the 30-day study period. The area under the curve based on times 1 and 3 showed that cortisol levels in the 1 cm hair segment closest to the scalp were moderately correlated with the 30-day salivary cortisol levels (r = 0.41, p = 0.047). However, this correlation was not observed for the cortisol awakening response, diurnal slope, or other metrics in different time domains. The mean salivary cortisol at time 3 was significantly correlated with hair cortisol (r = 0.42, p = 0.041). Intra-individual stability of the hair cortisol was maintained for at least 4 months. Hair cortisol may reflect basal cortisol levels more substantially over longer periods (longer than 1 month and for at least 4 month), thus reflecting longitudinal cortisol production, rather than the day-to-day temporal cortisol response. Salivary cortisol is an ideal metric for short-term or day-to-day stress response. Researchers should select suitable metrics, such as hair cortisol for basal level (or trait) or salivary cortisol for response (or state), depending on the study objective.
本研究旨在验证头发皮质醇与 30 天综合唾液皮质醇水平之间的关联。此外，还系统地探讨了头发皮质醇的个体内稳定性以及几个时间域内头发皮质醇与唾液皮质醇之间的关联。
24 名成年人（15 名男性和 9 名女性，平均年龄：22.7±2.8 岁）被要求在 30 天的研究期间每天采集 3 次唾液样本，分别在醒来后立即（时间 1）、醒来后 30 分钟（时间 2）和睡前（时间 3）。在 30 天研究结束时，从后顶点尽可能靠近头皮采集头发样本。基于时间 1 和 3 的曲线下面积显示，靠近头皮的 1 厘米头发段中的皮质醇水平与 30 天唾液皮质醇水平中度相关（r=0.41，p=0.047）。然而，在不同时间域的皮质醇觉醒反应、日间斜率或其他指标中并未观察到这种相关性。时间 3 的平均唾液皮质醇与头发皮质醇显著相关（r=0.42，p=0.041）。头发皮质醇的个体内稳定性至少可维持 4 个月。
头发皮质醇可能在更长的时间内（超过 1 个月且至少 4 个月）更能反映基础皮质醇水平，从而反映纵向皮质醇生成，而不是每日的皮质醇反应。唾液皮质醇是短期或每日应激反应的理想指标。研究人员应根据研究目的选择合适的指标，例如头发皮质醇用于基础水平（或特征），或唾液皮质醇用于反应（或状态）。
