Parasympathetic activity is reduced during slow-wave sleep, but not resting wakefulness, in patients with chronic fatigue syndrome

Abstract

Study Objectives: Physiological dearousal characterized by an increase in parasympathetic nervous system activity is important for good-quality sleep. Previous research shows that nocturnal parasympathetic activity (reflected by heart rate variability [HRV]) is diminished in individuals with chronic fatigue syndrome (CFS), suggesting hypervigilant sleep. This study investigated differences in nocturnal autonomic activity across sleep stages and explored the association of parasympathetic activity with sleep quality and self-reported physical and psychological wellbeing in individuals with CFS. Methods: Twenty-four patients with medically diagnosed CFS, and 24 matched healthy control individuals participated. Electroencephalography and HRV were recorded during sleep in participants' homes using a minimally invasive ambulatory device. Questionnaires were used to measure self-reported wellbeing and sleep quality. Results: Sleep architecture in patients with CFS differed from that of control participants in slower sleep onset, more awakenings, and a larger proportion of time spent in slow-wave sleep (SWS). Linear mixed-model analyses controlling for age revealed that HRV reflecting parasympathetic activity (normalized high frequency power) was reduced in patients with CFS compared to control participants, particularly during deeper stages of sleep. Poorer self-reported wellbeing and sleep quality was associated with reduced parasympathetic signaling during deeper sleep, but not during wake before sleep, rapid eye movement sleep, or with the proportion of time spent in SWS. Conclusions: Autonomic hypervigilance during the deeper, recuperative stages of sleep is associated with poor quality sleep and self-reported wellbeing. Causal links need to be confirmed but provide potential intervention opportunities for the core symptom of unrefreshing sleep in CFS.

Systematic Review of Sleep Characteristics in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

“…These terms were also excluded due to their broad nature, although this may have resulted in potentially relevant articles not being captured. Some studies also utilised components of polysomnography including EEG and discussed features of sleep but did not undergo the whole polysomnography process [ 39 ]. Additionally, two studies by Neu et al were not included in this review due to not containing any key words in the abstract or title [ 40 , 41 ].…”

Feature of Heart Rate Variability and Metabolic Mechanism in Female College Students with Depression

“…LF power is a compound regulatory function of the sympathetic nerve and vagus nerve, which further reflects the heart rate changes caused by baroreceptor reflex and blood pressure regulation [32]. Some research reported that HF and LF were significantly reduced in patients with chronic fatigue syndrome (CFS) or anxiety, which discovered there were an imbalance of cardiac autonomic nerves and the decreased cardiac vagus function in some mental illness [33,34]. Moreover, a recent study reported the average heart rate was increased in patients with depression [35].…”

The well-being of medical students: A biopsychosocial approach

“…In order to fall asleep, autonomic balance must switch to a parasympathetic dominant, recuperative mode, and the degree to which this is achieved is closely associated with a perception of good quality and refreshing sleep (Cvejic et al, 2018;Patel et al, 2013). We have previously documented that distress and ill health impede adequate induction of parasympathetic (vagal) activity leading, physiologically, to hypervigilant sleep that is typically reported as poor in quality and that impacts negatively on daytime functioning (Burton et al, 2010;Cvejic et al, 2017;Fatt et al, 2019).…”

“…Insufficient and poor quality sleep have been associated with physical and mental health problems, higher stress levels, burnout and reduced empathy, as well as drug and alcohol use (Lund et al, 2010;Wolf and Rosenstock, 2017). In addition, sleep impacts on cognitive performance and has a bidirectional link with autonomic and immune function (Cvejic et al, 2018;Fatt et al, 2019;Irwin, 2015). The autonomic nervous system (ANS) plays a complex role in the maintenance of physical and mental health (Beaumont et al, 2012;Thayer et al, 2009).…”

“…Measures of beat-to-beat heart rate variability (HRV) are widely recognized as valid indices of autonomic activity and reflect sympathetic/parasympathetic balance. Low parasympathetic (vagal) activity (best reflected in reduced HRV) has been reliably linked to disordered sleep, the perception of unrefreshing and poor quality sleep, as well as indices of well-being including psychiatric morbidity (Fatt et al, 2019;Kemp and Quintana, 2013).…”