School of Psychiatry, University of New South Wales, NSW, Australia; University of Sydney, School of Public Health, NSW, Australia.
UNSW Fatigue Clinic, University of New South Wales, NSW, Australia.
J Psychosom Res. 2017 Dec;103:91-94. doi: 10.1016/j.jpsychores.2017.10.010. Epub 2017 Oct 19.
To explore changes in autonomic functioning, sleep, and physical activity during a post-exertional symptom exacerbation induced by physical or cognitive challenge in participants with chronic fatigue syndrome (CFS).
Thirty-five participants with CFS reported fatigue levels 24-h before, immediately before, immediately after, and 24-h after the completion of previously characterised physical (stationary cycling) or cognitive (simulated driving) challenges. Participants also provided ratings of their sleep quality and sleep duration for the night before, and after, the challenge. Continuous ambulatory electrocardiography (ECG) and physical activity was recorded from 24-h prior, until 24-h after, the challenge. Heart rate (HR) and HR variability (HRV, as high frequency power in normalized units) was derived from the ECG trace for periods of wake and sleep.
Both physical and cognitive challenges induced an immediate exacerbation of the fatigue state (p<0.001), which remained elevated 24-h post-challenge. After completing the challenges, participants spent a greater proportion of wakeful hours lying down (p=0.024), but did not experience significant changes in sleep quality or sleep duration. Although the normal changes in HR and HRV during the transition from wakefulness to sleep were evident, the magnitude of the increase in HRV was significantly lower after completing the challenge (p=0.016).
Preliminary evidence of reduced nocturnal parasympathetic activity, and increased periods of inactivity, were found during post-exertional fatigue in a well-defined group of participants with CFS. Larger studies employing challenge paradigms are warranted to further explore the underlying pathophysiological mechanisms of post-exertional fatigue in CFS.
探讨慢性疲劳综合征（CFS）患者在体力或认知挑战后，因过度劳累症状加重而导致自主神经功能、睡眠和体力活动的变化。
35 名 CFS 患者在完成先前描述的体力（固定自行车）或认知（模拟驾驶）挑战前 24 小时、挑战前即刻、挑战后即刻和挑战后 24 小时报告他们的疲劳水平。参与者还提供了挑战前一天晚上和后一天晚上的睡眠质量和睡眠时间的评分。在挑战前 24 小时到挑战后 24 小时期间，连续进行动态心电图（ECG）和体力活动记录。从 ECG 记录中得出心率（HR）和心率变异性（HRV，以归一化单位中的高频功率表示），用于记录清醒和睡眠期间的 HR 和 HRV。
体力和认知挑战都立即引起疲劳状态的加重（p<0.001），这种状态在挑战后 24 小时仍然升高。完成挑战后，参与者在清醒时躺着的时间比例增加（p=0.024），但睡眠质量或睡眠时间没有明显变化。尽管在从清醒到睡眠的过渡过程中，HR 和 HRV 的正常变化是明显的，但在完成挑战后，HRV 的增加幅度明显降低（p=0.016）。
在一组明确诊断的 CFS 患者中，在过度劳累后疲劳期间发现了夜间副交感神经活动减少和不活动时间增加的初步证据。需要进行更大规模的研究，采用挑战范式来进一步探索 CFS 中过度劳累后疲劳的潜在病理生理机制。
