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Higher heart rate and reduced heart rate variability persist during sleep in chronic fatigue syndrome: A population-based study

Chronic Viral Diseases Branch, National Center for Zoonotic, Vector-borne and Enteric Diseases, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA.
Autonomic Neuroscience (Impact Factor: 1.37). 12/2007; 137(1-2):94-101. DOI: 10.1016/j.autneu.2007.08.002
Source: PubMed

ABSTRACT Autonomic nervous system (ANS) dysfunction has been suggested in patients with chronic fatigue syndrome (CFS). In this study, we sought to determine whether increased heart rate (HR) and reduced heart rate variability (HRV) parameters observed in CFS patients during wakefulness persist during sleep. To this end, we compared heart rate (HR) and HRV as indicators of ANS function in CFS subjects and non-fatigued (NF) controls in a population-based, case-control study. Thirty subjects with CFS and 38 NF controls, matched for age-, sex- and body mass index, were eligible for analysis. Main outcome measures included mean RR interval (RRI), HR, and HRV parameters derived from overnight ECG. Plasma aldosterone and norepinephrine levels, medicines with cardiovascular effect, and reported physical activity were examined as covariates. General Linear Models were used to assess significance of associations and adjust for potential confounders. Compared to controls, CFS cases had significantly higher mean HR (71.4 vs 64.8 bpm), with a shorter mean RRI [840.4 (85.3) vs 925.4(97.8) ms] (p<0.0004, each), and reduced low frequency (LF), very low frequency (VLF), and total power (TP) of HRV (p<0.02, all). CFS cases had significantly lower plasma aldosterone (p<0.05), and tended to have higher plasma norepinephrine levels. HR correlated weakly with plasma norepinephrine (r=0.23, p=0.05) and moderately with vitality and fatigue scores (r=-0.49 and 0.46, respectively, p<0.0001). Limitation in moderate physical activity was strongly associated with increased HR and decreased HRV. Nevertheless, among 42 subjects with similar physical activity limitations, CFS cases still had higher HR (71.8 bpm) than respective controls (64.9 bpm), p=0.023, suggesting that reduced physical activity could not fully explain CFS-associated differences in HR and HRV. After adjusting for potential confounders case-control differences in HR and TP remained significant (p<0.05). Conclusion: the presence of increased HR and reduced HRV in CFS during sleep coupled with higher norepinephrine levels and lower plasma aldosterone suggest a state of sympathetic ANS predominance and neuroendocrine alterations. Future research on the underlying pathophysiologic mechanisms of the association is needed.

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    • "Previous research has shown that there is a relationship between disrupted sleep patterns and chronic fatigue syndrome (CFS; Boneva et al., 2007; Morriss, Wearden, & Battersby, 1997; Togo et al., 2008). Sleep is a consistent complaint of those suffering from CFS; 87– 95% of patients with CFS report feeling unrefreshed on waking, despite adequate sleep duration (Hamaguchi, Kawahito, Takeda, Kato, & Kojima, 2011; Jason et al., 1999; Nisenbaum, Jones, Unger, Reyes, & Reeves, 2003; Nisenbaum, Reyes, Unger, & Reeves, 2004). "
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    ABSTRACT: Sleep disturbances are common in chronic fatigue syndrome (CFS), and one of the key symptom complaints, yet it has been neglected by previous qualitative research. The aim was to explore the specific role of sleep in patients' experience of their illness. A qualitative semi-structured interview format facilitated a detailed and open exploration of sleep, and the extent to which its management and problems were linked to the lived experience of CFS. Eleven semi-structured interviews were conducted with individuals with CFS. Data were transcribed verbatim and analysed thematically, to explore and describe patients' experience of their sleep, and its impact on their condition. Sleep emerged as a key aspect of the illness experience, and its management and effect on daytime functioning was a central pre-occupation for all 11 participants; all of them saw sleep as playing a critical role in their illness through either maintaining or exacerbating existing symptoms. Exploration of individual experiences presented three overarching themes: (1) sleep pattern variability over illness course and from day to day; (2) effect of sleep on daytime functioning; and (3) attempts at coping and sleep management. Each patient with CFS has a unique experience of sleep. Despite the differing narratives regarding the role of sleep in CFS, all participants held the belief that sleep is a vital process for health and well-being which has had a direct bearing on the course and progression of their CFS. Also, every participant regarded their sleep as in some way 'broken' and in need of management/repair. Patients' insights demonstrate sleep-specific influences on their CFS, and the impact of disturbed sleep should be a consideration for clinical and research work. Statement of contribution What is already known on this subject? Sleep disturbances are common in CFS, and one of the key symptom complaints, yet it has been neglected by previous qualitative research. Ontology of CFS is a matter of dispute, with models ranging from the biological to the psychological competing to explain symptomatology in this illness. A qualitative study has the potential to add some clarity to the debate by making the patients' lived experience of the condition, and their own understanding of it, the focus of research. What this study adds? Coping and attempts at managing sleep problems in CFS adds to the 'illness burden' experienced by patients. Disturbed sleep is universally seen by patients with CFS as impacting on other daytime symptoms. Broken sleep may contribute to a biopsychosocial cycle that serves to maintain this illness. © 2015 The British Psychological Society.
    British Journal of Health Psychology 02/2015; DOI:10.1111/bjhp.12136 · 2.70 Impact Factor
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    • "Healthy research participants made hypoglycemic with exogenous insulin demonstrate increased SNS tone assessed by heart rate variability [25] and manifestations of somatic arousal [26]. Among individuals diagnosed with chronic fatigue syndrome [27], fibromyalgia [28], IBS [29], Gulf War illness [30], and chronic insomnia [31], disorders associated with chronic stress [11] [12] [13] [14] [15], investigators have analyzed heart rate variability to demonstrate increased SNS tone. Thus, disorders conceptualized as having a common basis of stress are characterized by increased SNS tone and somatic arousal. "
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    ABSTRACT: Objectives We tested the hypothesis that the symptoms of upper airway resistance syndrome (UARS) are manifestations of chronic stress. To accomplish this we utilized the score on a self-report questionnaire for somatic arousal (a component of stress) to compare somatic arousal between UARS patients and healthy controls and, among all participants, to correlate the level of somatic arousal with the severity of UARS symptoms. Methods We administered the Mood and Anxiety Symptom Questionnaire anxious arousal subscale (MASQaas; a 17-item questionnaire with increasing levels of arousal scored 17-85) to 12 UARS patients and 12 healthy controls and compared scores between groups. For all participants, we correlated the MASQaas scores with scores for the Epworth Sleepiness Scale (ESS), Functional Assessment of Chronic Illness Therapy – Fatigue (FACIT-fatigue) scale, Pittsburgh Sleep Quality Index (PSQI), SF-36 Health Survey and Perceived Deficits Questionnaire (PDQ; assessing cognitive function). Results Compared to healthy controls, UARS patients demonstrated increased somatic arousal (MASQaas scores of 18 ± 2 and 28 ± 7 respectively; p < 0.0001). For all participants, the MASQaas scores correlated significantly with scores of the ESS (r = 0.64; p = 0.0008), the FACIT-fatigue scale (r = -0.89; p < 0.0001), the PSQI (r = 0.70; p = 0.0002), SF-36 Physical component (r = -0.78; p < 0.0001), SF-36 Mental component (r = -0.74; p < 0.0001) and the PDQ (r = 0.89; p < 0.0001). Conclusions Our findings suggest that UARS patients have increased levels of the stress component, somatic arousal, proportionate to the severity of their symptoms.
    Sleep Medicine 04/2014; DOI:10.1016/j.sleep.2014.01.014 · 3.10 Impact Factor
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    • "Patients with CFS develop increased HR, reduced HRV (Yamamoto et al., 2003), and increased symptoms (Bou-Holaigah et al., 1995) during orthostatic challenge. A population-based study also found increased HR and reduced HRV in CFS patients during sleep as well as a significant correlation between high norepinephrine levels and higher HR in CFS patients (Boneva et al., 2007) – possibly reflecting increased sympathetic tone to the heart. In line with these studies, our present study showed lower mean RRI, higher ratio of LF to HF, and a non-significant trend for lower HF, LF, and VLF powers of whole night HRV for patients in the a.m. "
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    ABSTRACT: We determined whether alterations in heart rate dynamics during sleep in patients with chronic fatigue syndrome (CFS) differed from controls and/or correlated with changes of sleepiness before and after a night in the sleep laboratory. We compared beat-to-beat RR intervals (RRI) during nocturnal sleep, sleep structure, and subjective scores on visual analog scale for sleepiness in 18 CFS patients with 19 healthy controls aged 25-55 after excluding subjects with sleep disorders. A short-term fractal scaling exponent (α1) of RRI dynamics, analyzed by the detrended fluctuation analysis (DFA) method, was assessed after stratifying patients into those who reported more or less sleepiness after the night's sleep (a.m. sleepier or a.m. less sleepy, respectively). Patients in the a.m. sleepier group showed significantly (p<0.05) higher fractal scaling index α1 during non-rapid eye movement (non-REM) sleep (Stages 1, 2, and 3 sleep) than healthy controls, although standard polysomnographic measures did not differ between the groups. The fractal scaling index α1 during non-REM sleep was significantly (p<0.05) lower than that during awake periods after sleep onset for healthy controls and patients in the a.m. less sleepy group, but did not differ between sleep stages for patients in the a.m. sleepier group. For patients, changes in self-reported sleepiness before and after the night correlated positively with the fractal scaling index α1 during non-REM sleep (p<0.05). These results suggest that RRI dynamics or autonomic nervous system activity during non-REM sleep might be associated with disrupted sleep in patients with CFS.
    Autonomic neuroscience: basic & clinical 03/2013; DOI:10.1016/j.autneu.2013.02.015 · 1.37 Impact Factor
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