Holst Centre, imec-the Netherlands, Eindhoven, Netherlands.
OnePlanet Research Center, imec-the Netherlands, Wageningen, Netherlands.
J Med Internet Res. 2020 Sep 9;22(9):e18253. doi: 10.2196/18253.
Chronic stress is increasing in prevalence and is associated with several physical and mental disorders. Although it is proven that acute stress changes physiology, much less is known about the relationship between physiology and long-term stress. Continuous measurement of vital signs in daily life and chronic stress detection algorithms could serve this purpose. For this, it is paramount to model the effects of chronic stress on human physiology and include other cofounders, such as demographics, enabling the enrichment of a population-wide approach with individual variations.
The main objectives of this study were to investigate the effect of chronic stress on heart rate (HR) over time while correcting for weekdays versus weekends and to test a possible modulation effect by gender and age in a healthy cohort.
Throughout 2016 and 2017, healthy employees of technology companies were asked to participate in a 5-day observation stress study. They were required to wear two wearables, of which one included an electrocardiogram sensor. The derived HR was averaged per hour and served as an output for a mixed design model including a trigonometric fit over time with four harmonics (periods of 24, 12, 8, and 6 hours), gender, age, whether it was a workday or weekend day, and a chronic stress score derived from the Perceived Stress Scale (PSS) as predictors.
The study included 328 subjects, of which 142 were female and 186 were male participants, with a mean age of 38.9 (SD 10.2) years and a mean PSS score of 13.7 (SD 6.0). As main effects, gender (χ=24.02, P<.001); the hour of the day (χ=73.22, P<.001); the circadian harmonic (χ=284.4, P<.001); and the harmonic over 12 hours (χ=242.1, P<.001), over 8 hours (χ=23.78, P<.001), and over 6 hours (χ=82.96, P<.001) had a significant effect on HR. Two three-way interaction effects were found. The interaction of age, whether it was a workday or weekend day, and the circadian harmonic over time were significantly correlated with HR (χ=7.13, P=.03), as well as the interaction of gender, PSS score, and the circadian harmonic over time (χ=7.59, P=.02).
The results show a relationship between HR and the three-way interaction of chronic stress, gender, and the circadian harmonic. The modulation by gender might be related to evolution-based energy utilization strategies, as suggested in related literature studies. More research, including daily cortisol assessment, longer recordings, and a wider population, should be performed to confirm this interpretation. This would enable the development of more complete and personalized models of chronic stress.
慢性压力的发病率正在上升，与多种身心障碍有关。虽然已经证明急性压力会改变生理机能，但对于长期压力与生理机能之间的关系，人们了解得较少。连续测量日常生活中的生命体征和慢性压力检测算法可以满足这一需求。为此，必须对慢性压力对人体生理机能的影响进行建模，并纳入其他混杂因素，如人口统计学因素，以便利用个体差异丰富人群范围的方法。
本研究的主要目的是在纠正工作日与周末差异的同时，调查慢性压力对心率（HR）随时间变化的影响，并测试健康队列中性别和年龄的可能调节作用。
在 2016 年至 2017 年间，科技公司的健康员工被要求参加为期 5 天的观察性应激研究。他们被要求佩戴两个可穿戴设备，其中一个包括心电图传感器。每小时平均得出 HR，并作为混合设计模型的输出，该模型包括一个随时间变化的三角函数拟合，有四个谐波（周期为 24、12、8 和 6 小时）、性别、年龄、是否为工作日或周末以及源自感知压力量表（PSS）的慢性压力得分作为预测因子。
该研究纳入了 328 名参与者，其中 142 名为女性，186 名为男性，平均年龄为 38.9（标准差 10.2）岁，平均 PSS 评分为 13.7（标准差 6.0）。作为主要效应，性别（χ=24.02，P<.001）；时间的小时（χ=73.22，P<.001）；昼夜节律谐波（χ=284.4，P<.001）；12 小时谐波（χ=242.1，P<.001）、8 小时谐波（χ=23.78，P<.001）和 6 小时谐波（χ=82.96，P<.001）对 HR 有显著影响。发现了两个三因素相互作用效应。年龄、工作日或周末以及昼夜节律随时间变化的三因素相互作用与 HR 显著相关（χ=7.13，P=.03），以及性别、PSS 评分和昼夜节律随时间变化的三因素相互作用与 HR 显著相关（χ=7.59，P=.02）。
结果显示 HR 与慢性压力、性别和昼夜节律三因素相互作用之间存在关系。性别调节可能与相关文献研究中提出的基于进化的能量利用策略有关。应该进行更多的研究，包括日常皮质醇评估、更长时间的记录和更广泛的人群，以证实这一解释。这将能够开发出更完整和个性化的慢性压力模型。
