Reduced heart rate variability predicts poor sleep quality in a case–control study of chronic fatigue syndrome

Abstract

Parasympathetic function is important in the induction and maintenance of sleep. We examined whether nocturnal vagal modulation of heart rate is related to the poor sleep quality commonly reported in chronic fatigue syndrome (CFS). Heart rate (HR, as R-R intervals) was continuously monitored during sleep in 20 patients with CFS and 20 matched control subjects. Questionnaires assessed demographic information, symptoms, functional impairment, and subjective sleep quality. CFS was associated with more sleep problems in general and poorer subjective sleep quality on the study night (all p < 0.003), and reports of repeated awakening during the night were 7 times more likely compared to healthy subjects (p = 0.017). Time and frequency-domain parameters of HR variability during sleep were significantly lower in patients with CFS (all p < 0.006). Multiple regression analyses revealed that heart rate variability (HRV) parameters were the best predictors of subjective sleep measures. This study identified significant reductions in vagal modulation of heart rate during sleep in CFS. Low HRV strongly predicted sleep quality-suggesting a pervasive state of nocturnal sympathetic hypervigilance in CFS.

Health and distress predictors of heart rate variability in fibromyalgia and other forms of chronic pain

“…In addition, little attention has been paid to other factors that may be related to HRV function in individuals with pain conditions. For example, anxiety, depression, health impairments, and poor sleep were related to reduced HRV while active and acceptance coping were related to increased HRV across a number of studies and conditions [12,[15][16][17][18][19]. Given the known association between chronic benign pain and many of these factors, examining the role of these psychosocial factors in autonomic function of individuals with chronic pain warrants further exploration.…”

Sleep Abnormalities in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Review

“…75 HRV during sleep is consistently found to be significantly lower in CFS/ME patients compared to wellmatched controls, reflecting a reduction in nocturnal parasympathetic activity. 39,43,75,76 Decreased HRV is thought to reflect a persistent state of autonomic hypervigilance. The influence of daytime physical activity, however, should not be dismissed as a potential confounder.…”

“…Regression analyses have also demonstrated that HRV is the best predictor of subjective sleep quality in CFS/ME patients in one study. 39 Cardiopulmonary coupling (CPC) is another emerging technique, used as a measure of sleep quality and stability based solely on the electrocardiogram (ECG) signal. 77 This technique records both heart rate (R-R interval) and respiration dynamics to generate a spectrogram of cardiopulmonary coupling.…”

“…4,37 It has been reported that CFS/ME patients may have differential parasympathetic activity at sleep onset, which may contribute to delayed sleep latency. 39 This finding could also reflect poor sleep hygiene or extended sleep periods and napping, which may reduce sleep drive at night. Actigraphy studies potentially provide a more ecologically valid assessment of TST, sleep efficiency, and sleep onset latency parameters, as measurements are made in a naturalistic setting where patients can follow their usual sleep routines.…”

Observación automatizada: la variabilidad de la frecuencia cardíaca y su relación con las variables psicológicas determinantes del rendimiento en nadadores jóvenes

“…Given that HRV depends on the modulation of the autonomic nervous system, which has obvious implications in terms of emotional states, some authors have analyzed links between HRV and psychological aspects that can affect sports performance, such as anxiety (Cervantes, Rodas, and Capdevila, 2009;Morales et al, 2013) and a poor sleep quality, which can be predictors of a chronic fatigue syndrome (Burton et al 2010;Plews et al 2012). In the case of anxiety, HRV has been found to be susceptible to changes in anxiety levels in precompetition situations.…”