Sleep-wake rhythm disturbances and perceived sleep in adolescent chronic fatigue syndrome

Correlation Between Chronotypes and Depressive Symptoms Mediated by Sleep Quality Among Chinese College Students During the COVID-19 Pandemic

Purpose

The COVID-19 pandemic has adversely impacted the mental health of the population. The current study aimed to determine the prevalence of depressive symptoms and sleep disturbances among Chinese college students during the COVID-19 pandemic and investigate the correlations between chronotypes, sleep quality, and depressive symptoms.

Participants and Methods

In the current study, 2526 college students responded anonymously to an online questionnaire survey from 26 May 2020 to 20 July 2020. The participants' chronotypes, sleep quality, and depressive symptoms were evaluated using the Chinese version of the Morning and Evening Questionnaire-5 (MEQ-5), Pittsburgh Sleep Quality Index (PSQI), and Patient Health Questionnaire-9 (PHQ-9). Sociodemographic information of the participants was also acquired. Statistical analyses were performed using Statistical Package for Social Sciences (SPSS) 19.0 software, with the mediating effect assessed by Hayes' PROCESS Macro.

Results

During the COVID-19 pandemic, the prevalence of depressive symptoms and sleep disturbances among Chinese college students surveyed was 54.95% and 48.18%, respectively. From absolute evening chronotype to absolute morning chronotype, the surveyed college students' chronotypes were negatively correlated with their depressive symptoms. Moreover, the mediation analysis showed that the correlation between chronotypes and depressive symptoms was fully mediated by sleep quality. Eveningness college students with poorer sleep quality were more likely to report higher levels of depressive symptoms.

Conclusion

Our findings suggest that during the COVID-19 pandemic, delayed circadian preference (ie, eveningness) may be linked to worse depressive symptoms among Chinese college students, and call for more attention to the sleep quality of Chinese college students as sleep quality fully mediated the correlation between chronotypes and depressive symptoms among them. Reasonable adjustment in bedtime/circadian preference and improvement in sleep quality may help to reduce the prevalence and severity of depressive symptoms among Chinese college students.

Objective sleep measures in chronic fatigue syndrome patients: A systematic review and meta-analysis

Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often report disrupted and unrefreshing sleep in association with worsened fatigue symptoms. However, the nature and magnitude of sleep architecture alteration in ME/CFS is not known, with studies using objective sleep measures in ME/CFS generating contradictory results. The current manuscript aimed to review and meta-analyse of case-control studies with objective sleep measures in ME/CSF. A search was conducted in PubMed, Scopus, Medline, Google Scholar, and Psychoinfo databases. After review, 24 studies were included in the meta-analysis, including 20 studies with 801 adults (ME/CFS = 426; controls = 375), and 4 studies with 477 adolescents (ME/CFS = 242; controls = 235), who underwent objective measurement of sleep. Adult ME/CFS patients spend longer time in bed, longer sleep onset latency, longer awake time after sleep onset, reduced sleep efficiency, decreased stage 2 sleep, more Stage 3, and longer rapid eye movement sleep latency. However, adolescent ME/CFS patients had longer time in bed, longer total sleep time, longer sleep onset latency, and reduced sleep efficiency. The meta-analysis results demonstrate that sleep is altered in ME/CFS, with changes seeming to differ between adolescent and adults, and suggesting sympathetic and parasympathetic nervous system alterations in ME/CFS.

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in Adolescents: Practical Guidance and Management Challenges

This paper reviews the current understanding of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and whether any treatment strategies have been effective. ME/CFS is a condition of as yet unknown etiology that commonly follows an infective process. It includes a new onset of fatigue (of more than 3-6 month duration and not relieved by rest), post-exertional malaise, cognitive difficulties and unrefreshing sleep, and frequently orthostatic intolerance, somatic symptoms and pain. Long COVID has renewed interest in the condition and stimulated research with findings suggestive of a multisystem neuroimmune disease. There are no definitively effective treatments. Despite earlier recommendations regarding graded exercise therapy and cognitive behavior therapy, the current recommendations are managing symptoms, with lifestyle management and supportive care. This paper provides an outline of strategies that young people and their families have reported as helpful in managing a chronic illness that impacts their life socially, physically, emotionally, cognitively and educationally. As the illness frequently occurs at a time of rapid developmental changes, reducing these impacts is reported to be as important as managing the physical symptoms. Young people face a mean duration of 5 years illness (range 1-16 years) with a likely residual 20% having significant restrictions after 10 years. Their feedback has suggested that symptom management, self-management strategies, advocacy and educational liaison have been the most helpful. They value professionals who will listen and take them seriously, and after excluding alternative diagnoses, they explain the diagnosis, are supportive and assist in monitoring their progress. Remaining engaged in education was the best predictor of later functioning. This allowed for social connections, as well as potential independence and fulfilling some aspirations. The need to consider the impact of this chronic illness on all aspects of adolescent development, as part of management, is highlighted.

The Qigong of Prolong Life With Nine Turn Method Relieve Fatigue, Sleep, Anxiety and Depression in Patients With Chronic Fatigue Syndrome: A Randomized Controlled Clinical Study

Background

Chronic fatigue syndrome (CFS) is a complex disease of unknown etiology and mechanism. The purpose of this study was to investigate the effect of Prolong Life with Nine Turn Method (PLWNT) Qigong exercise on CFS focusing on fatigue, sleep quality, depression, and anxiety.

Methods

A total of 90 participants diagnosed with CFS were randomly assigned into two parallel groups: PLWNT and cognitive behavioral therapy (CBT). The participants in the PLWNT or CBT group participated in qigong exercise or cognitive behavior education program, respectively, once a week in-person and were supervised online during the remaining 6 days at home, over 12 consecutive weeks. The primary outcome was fatigue (Multi-dimensional Fatigue Inventory 20 [MFI-20]), and secondary outcomes were sleep quality (Pittsburgh Sleep Quality Index [PSQI]), anxiety, depression (Hospital Anxiety and Depression Scale [HADS]), and changes in the Neuropeptide Y (NPY) of peripheral blood.

Results

The within-group comparisons of the PLWNT and CBT groups revealed significant improvement in both groups in MFI-20, PSQI, and HADS scores (P < 0.05). No significant difference were found between the PLWNT and CBT groups, even though the effective rate of the PLWNT group was 62.22%, which is slightly than 50.00% of the CBT group. The fatigue scores in the PLWNT group were positively correlated with sleep degree (r = 0.315) and anxiety degree (r = 0.333), only anxiety degree (r = 0.332) was found to be positively correlated with fatigue in the CBT group. The analysis of peripheral blood showed that NPY decreased after PLWNT intervention but increased significantly in the CBT.

Conclusion

The PLWNT qigong exercise has potential to be an effective rehabilitation method for CFS symptoms including fatigue, sleep disturbance, anxiety, and depression. Future studies should expand study sample size for in-depth investigation to determine the optimal frequency and intensity of PLWNT qigong intervention in CFS patients. The study was registered in the ClinicalTrials.gov database on April 12, 2018, with registration number NCT03496961.

Match or mismatch between chronotype and sleep-wake cycle and their association with lean body mass gain among male high-school baseball players

For athletes, it is important to acquire lean body mass (LBM) involving the skeletal muscle mass during their growth periods; however, the influence of chronotype on LBM gain remains unclear. We therefore aimed to investigate whether chronotype, sleep-wake cycle on weekdays (SWC-W), and their interaction contribute to LBM gain among adolescent male athletes in a 4-month intervention study. The participants were 45 male high-school baseball players. The intervention, including exercise menu (running and muscle strength training) and nutritional education, was conducted during a 4-month period of season-off training. The chronotype, body composition, lifestyle, and dietary intake were investigated before intervention (baseline) and after 4 months. Among the participants [Morningness (n = 14), Eveningness (n = 15), Intermediate (n = 16); ME score based on the Morningness/Eveningness Scale for Children (MES-C)], the midpoint of sleep on weekdays (MSW) was calculated in the "Morningness" and "Eveningness" participants, respectively. They were divided into 4 groups based on a match/mismatch with the chronotype: Type M-match (n = 8), Type M-mismatch (n = 6), Type E-match (n = 7), and Type E-mismatch (n = 8) groups. The data were compared among the 4 groups. Moreover, multiple regression analysis was conducted using an increase (kg) LBM gain as a response variable. When comparing the data between the "Morningness" and "Eveningness" participants, there were no differences in nutrient intake, the duration of training, or each parameter of body composition (per body weight) at baseline or after 4 months. There were also no differences in the rates of change in the body weight or each parameter of body composition. In groups in which the chronotype was consistent with the SWC-W (the Type M-match and Type E-match groups), the LBM gain were slightly greater than in the Type M-mismatch and Type E-mismatch groups (Type M-match: 3.5 ± 2.0 kg, Type M-mismatch: 1.6 ± 1.7 kg, Type E-match: 3.4 ± 2.2 kg, and Type E-mismatch: 1.2 ± 1.8 kg, p = .057). Multiple regression analysis revealed that an extent of the LBM gain was associated with a match between the chronotype and SWC-W (ß = 0.37, p = .030), independent of a long duration of training (ß = 0.52, p = .004). The results suggested that training-related LBM gain is associated with interactions between the chronotype and SWC-W in adolescent male athletes.Abbreviations: LBM: Lean body mass; SWC-W: Sleep-wake cycle on weekdays; ME score: Morningness-eveningness score; MES-C: Morningness/Eveningness Scale for Children; MSW: Midpoint of sleep on weekdays; MSF: Midpoint of sleep on free days; MSFsc: Midpoint of sleep on free days corrected for sleep debt accumulated through weekdays.

Sleep-wake rhythm disruption is associated with cancer-related fatigue in pediatric acute lymphoblastic leukemia

Study Objectives

To compare sleep–wake rhythms, melatonin, and cancer-related fatigue in pediatric patients with acute lymphoblastic leukemia (ALL) to healthy children and to assess the association between sleep–wake outcomes and cancer-related fatigue.

Methods

A national cohort of ALL patients (2–18 years) was included. Sleep–wake rhythms were measured using actigraphy and generated the following variables: Interdaily stability (IS): higher IS reflects higher stability; intradaily variability (IV): lower IV indicates less fragmentation; L5 and M10 counts: activity counts during the five least and 10 most active hours, respectively; and relative amplitude (RA): the ratio of L5 and M10 counts (higher RA reflects a more robust rhythm). The melatonin metabolite, 6-sulfatoxymelatonin (aMT6s), was assessed in urine. Cancer-related fatigue was assessed with the PedsQL Multidimensional Fatigue Scale. Using regression models sleep–wake rhythms, aMT6s, and cancer-related fatigue were compared to healthy children and associations between sleep–wake outcomes and cancer-related fatigue were assessed in ALL patients.

Results

In total, 126 patients participated (response rate: 67%). IS, RA, and M10 counts were lower in patients compared to healthy children (p < 0.001). aMT6s levels were comparable to healthy children (p = 0.425). Patients with ALL were more fatigued compared to healthy children (p < 0.001). Lower IS, RA and M10 counts and higher IV were significantly associated with more parent-reported cancer-related fatigue. Associations between sleep–wake rhythms and self-reported cancer-related fatigue were not statistically significant.

Conclusions

Sleep–wake rhythm impairment is associated with more cancer-related fatigue in pediatric ALL patients. Interventions aimed to improve sleep hygiene and encourage physical activity may reduce cancer-related fatigue.

Mitochondria and immunity in chronic fatigue syndrome

It is widely accepted that the pathophysiology and treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) could be considerably improved. The heterogeneity of ME/CFS and the confusion over its classification have undoubtedly contributed to this, although this would seem a consequence of the complexity of the array of ME/CFS presentations and high levels of diverse comorbidities. This article reviews the biological underpinnings of ME/CFS presentations, including the interacting roles of the gut microbiome/permeability, endogenous opioidergic system, immune cell mitochondria, autonomic nervous system, microRNA-155, viral infection/re-awakening and leptin as well as melatonin and the circadian rhythm. This details not only relevant pathophysiological processes and treatment options, but also highlights future research directions. Due to the complexity of interacting systems in ME/CFS pathophysiology, clarification as to its biological underpinnings is likely to considerably contribute to the understanding and treatment of other complex and poorly managed conditions, including fibromyalgia, depression, migraine, and dementia. The gut and immune cell mitochondria are proposed to be two important hubs that interact with the circadian rhythm in driving ME/CFS pathophysiology.

Sleep problems in adolescents with CFS: A case-control study nested within a prospective clinical cohort

Sleep problems have a negative impact on a range of outcomes and are very common in adolescents with chronic fatigue syndrome (CFS). We aimed to (a) establish whether adolescents with CFS have more self-reported sleep problems than illness controls as well as healthy controls, (b) investigate changes in sleep problems and (c) explore the extent to which sleep problems at baseline predict fatigue and functioning at follow-up in adolescents with CFS. The Insomnia Scale was completed by 121 adolescents with CFS, 78 healthy adolescents and 27 adolescents with asthma. Eighty (66%) treatment-naïve adolescents with CFS completed questionnaires approximately 3 months later. Adolescents with CFS reported increased sleep problems compared to healthy controls and adolescents with asthma. In CFS, there was no significant change in sleep problems without treatment over a 3-month follow-up. Sleep problems at baseline predicted a significant proportion of the variance in sleep problems at follow-up. Sleep problems should be targeted in treatment. Regulating the 'body clock' via the regulation of sleep could influence outcomes not assessed in this study such as school attainment.

Cognitive-behavioural therapy combined with music therapy for chronic fatigue following Epstein-Barr virus infection in adolescents: a feasibility study

​BACKGROUND

Cognitive-behavioural therapy (CBT) is effective in chronic fatigue syndrome. However, CBT has not been investigated in postinfectious chronic fatigue (CF), nor is it known whether addition of therapeutic elements from other disciplines might be feasible. We studied the feasibility of a combined CBT and music therapy intervention for CF following Epstein-Barr virus (EBV) infection in adolescents.

​METHODS

Adolescents (12-20 years old) participating in a postinfectious cohort study who developed CF 6 months after an acute EBV infection were eligible for the present feasibility study. A combined CBT and music therapy programme (10 therapy sessions and related homework) was compared with care as usual in a randomised controlled design. Therapists and participants were blinded to outcome evaluation. Endpoints included physical activity (steps/day), symptom scores, recovery rate and possible harmful effects, but the study was underpowered regarding efficacy. Total follow-up time was 15 months.

​RESULTS

A total of 43 individuals with postinfectious CF were included (21 intervention group, 22 control group). Seven individuals left the study during the first 3 months, leaving 15 in the intervention group and 21 in the control group at 3 months' follow-up. No harmful effects were recorded, and compliance with appointment was high. In intention-to-treat analyses, number of steps/day tended to decrease (difference=-1158, 95% CI -2642 to 325), whereas postexertional malaise tended to improve (difference=-0.4, 95% CI -0.9 to 0.1) in the intervention group at 3 months. At 15 months' follow-up, there was a trend towards higher recovery rate in the intervention group (62% vs 37%).

​CONCLUSION

An intervention study of combined CBT and music therapy in postinfectious CF is feasible, and appears acceptable to the participants. The tendencies towards positive effects on patients' symptoms and recovery might justify a full-scale clinical trial.

​TRIAL REGISTRATION NUMBER

NCT02499302.

Actigraphic estimates of sleep and the sleep-wake rhythm, and 6-sulfatoxymelatonin levels in healthy Dutch children

Sleep and the sleep-wake rhythm are essential for children's health and well-being, yet reference values are lacking. This study therefore aimed to assess actigraphic estimates of sleep and the 24-h sleep-wake rhythm, as well as 6-sulfatoxymelatonin (aMT6s) levels in healthy children of different age groups. Additionally, relationships between the outcomes and sex, highest parental educational level (as an indication of socioeconomic status (SES)), and body-mass-index (BMI) were explored. In this cross-sectional study, healthy Dutch children (2-18 years) wore an actigraph (GT3x) for 7 consecutive days, collected first-morning void urine and completed a sleep log and sociodemographic questionnaire. Actigraphically estimated sleep variables were sleep onset latency (SOL), sleep efficiency (SE), total sleep time (TST), and wake after sleep onset (WASO). Non-parametric sleep-wake rhythm variables were intradaily variability (IV); interdaily stability (IS); the activity counts and timing of the least active 5-h period (L5counts and midpoint) and of the most active 10-h period (M10 counts and midpoint); and the relative amplitude (RA), i.e. the ratio of the difference and the sum of M10 and L5 counts. Finally, creatinine-corrected aMT6s levels were obtained by isotope dilution mass spectrometry. Effects of age group (preschool 2-5 years/school-aged 6-12 years/teenager 13-18 years), sex, highest parental educational level and BMI (Z-scores) were explored. Ninety-four children participated, equally divided across age groups (53% boys). Teenagers slept less, but more efficiently, than younger children, while their 24 h sleep-wake rhythm was the least stable and most fragmented (likely due to fragmentation of daytime activity). Additionally, aMT6s levels significantly declined over the age groups. Children from highly educated parents had lower sleep efficiency, but a more stable sleep-wake rhythm. Finally, sex or increase in BMI was not associated with any of the outcomes in this study. In conclusion, this study provides reference values of healthy children across different age groups and different sociodemographic factors. In the future, this information may help to better interpret outcomes in clinical populations.

Cognitive-behavioural therapy combined with music therapy for chronic fatigue following Epstein-Barr virus infection in adolescents: a randomised controlled trial

BACKGROUND

Cognitive-behavioural therapy (CBT) is effective in chronic fatigue (CF) syndrome. However, CBT has not been investigated in postinfectious CF, nor is it known whether addition of therapeutic elements from other disciplines might be useful. We explored combined CBT and music therapy intervention for CF following Epstein-Barr virus (EBV) infection in adolescents.

METHODS

Adolescents (12-20 years old) participating in a postinfectious cohort study who developed CF 6 months after an acute EBV infection were eligible for the present study. A combined CBT and music therapy programme (10 therapy sessions and related homework) was compared with care as usual in a randomised controlled design. Therapists and participants were blinded to outcome evaluation. Endpoints included physical activity (steps/day), symptom scores, recovery rate and possible harmful effects, but the study was underpowered regarding efficacy. Total follow-up time was 15 months. Power analyses suggested that 120 participants would be needed in order to detect a moderate effect size.

RESULTS

A total of 91 individuals with postinfectious CF were eligible, and a total of 43 were included (21 intervention group, 22 control group). Concern regarding school absence due to therapy sessions was the main reason for declining participation. Seven individuals left the study during the first 3 months, leaving 15 in the intervention group and 21 in the control group at 3 months follow-up. No harmful effects were recorded, and compliance with appointment was high. In intention-to-treat analyses, the primary endpoint (number of steps/day) did not differ significantly between the intervention group and the control group (difference (95% CI) =-1298 (-4874 to 2278)). Secondary outcome measures were also not significantly different among the two groups.

CONCLUSION

An intervention study of combined CBT and music therapy in postinfectious CF is feasible. A fully powered trial is needed to evaluate efficacy; participants' concern regarding school absence should be properly addressed to secure recruitment.

TRIAL REGISTRATION NUMBER

ClinicalTrials ID: NCT02499302, registered July 2015.

Chronic Fatigue Syndrome and chronic pain conditions - vitally protective systems gone wrong

Chronic Fatigue Syndrome (CFS) and chronic pain syndromes represent major health problems in society. These conditions are disabling and strongly associated with low quality of life. Even though CFS and chronic pain are separate conditions, they have strikingly much in common. Both pain and fatigue are important sensations with protective value in an acute situation. It can be life-threatening not to be aware of them. However, as these symptoms become chronic, their protective roles decrease and instead they become health problems. Our understanding of the perception of pain and fatigue has shifted through the years, from a dualistic biomedical point of view to a holistic biopsychosocial understanding. This combined with the increasing evidence of how our brain works in a predictive/anticipatory manner, gives a deeper understanding of why treatments like cognitive behavior therapies and stress relief therapies can help these patients recover to better health.

Fatigue in Epstein-Barr virus infected adolescents and healthy controls: A prospective multifactorial association study

OBJECTIVE

Acute Epstein-Barr virus (EBV) infection is a known trigger of both acute and chronic fatigue. The aim of this study was to investigate associations to fatigue in adolescents with EBV infection during the initial stage and six months after, as well as in healthy controls.

METHODS

200 adolescents (12-20 years old) with EBV infection were assessed as soon as possible after the onset of symptoms (EBV_baseline) and six months later (EBV_{six months}, 5 drop-outs). Also, 70 healthy controls (HC) were included. Associations between current fatigue and 148 different variables (including symptoms, functional abilities and biomarkers) were investigated separately for EBV_baseline, EBV_{six months} and HC using linear regression modelling.

RESULTS

Fatigue was associated with symptoms of sleeping difficulties, negative emotions, and quality of life under all circumstances. Fatigue was independently associated with markers of immune response at EBV_{six months} and in HC, not at EBV_baseline. An association between fatigue and markers of autonomic cardiovascular control was only present at EBV_{six months}. Cognitive functioning shifted from a positive association to fatigue at EBV_baseline to a negative trend at EBV_{six months.} Markers of infection were not associated with fatigue at EBV_baseline, EBV_{six months} nor in HC.

CONCLUSION

Irrespective of the cause, fatigue is important for quality of life and is highly associated with negative emotions. Markers of infection and immune response had respectively none and barely any association to fatigue. Autonomic alterations and cognitive dysfunction were exclusively associated with fatigue long after infection, corroborating findings from studies of the Chronic Fatigue Syndrome.

Non-restorative Sleep Caused by Autonomic and Electroencephalography Parameter Dysfunction Leads to Subjective Fatigue at Wake Time in Shift Workers

Sleep is a physiological state that plays important role in the recovery of fatigue. However, the relationship between the physiological status of sleep and subjective fatigue remains unknown. In the present study, we hypothesized that the non-recovery of fatigue at wake time due to non-restorative sleep might be ascribed to changes in specific parameters of electroencephalography (EEG) and heart rate variability (HRV) in poor sleepers. Twenty healthy female shift-working nurses participated in the study. Subjective fatigue was assessed using the visual analog scale (VAS) at bedtime and wake time. During sleep on the night between 2 consecutive day shifts, the EEG powers at the frontal pole, HRV based on electrocardiograms, and distal-proximal gradient of skin temperature were recorded and analyzed. The results indicated that the subjects with high fatigue on the VAS at wake time exhibited (1) a decrease in deep non-rapid eye movement (NREM) (stageN3) sleep duration in the first sleep cycle; (2) a decrease in REM latency; (3) a decrease in ultra-slow and delta EEG powers, particularly from 30 to 65 min after sleep onset; (4) a decrease in the total power of HRV, particularly from 0 to 30 min after sleep onset; (5) an increase in the very low frequency component of HRV; and (6) a smaller increase in the distal-proximal gradient of skin temperature, than those of the subjects with low fatigue levels. The correlational and structural equation modeling analyses of these parameters suggested that an initial decrease in the total power of HRV from 0 to 30 min after sleep onset might inhibit the recovery from fatigue during sleep (i.e., increase the VAS score at wake time) via its effects on the ultra-slow and delta powers from 30 to 65 min after sleep onset, stageN3 duration in the first sleep cycle, REM latency, and distal-proximal gradient of skin temperature. These findings suggest an important role of these physiological factors in recovery from fatigue during sleep, and that interventions to modify these physiological factors might ameliorate fatigue at wake time.

Predictors of chronic fatigue in adolescents six months after acute Epstein-Barr virus infection: A prospective cohort study

INTRODUCTION

Acute Epstein-Barr virus (EBV) infection is a trigger of chronic fatigue and Chronic Fatigue Syndrome (CFS). This study investigated baseline predictors of chronic fatigue six months after an acute EBV infection.

MATERIALS AND METHODS

A total of 200 adolescents (12-20 years old) with acute EBV infection were assessed for 149 possible baseline predictors and followed prospectively. We performed linear regression to assess possible associations between baseline predictors and fatigue (Chalder Fatigue Questionnaire total score) six months after the acute EBV infection. A total of 70 healthy controls were included for cross-sectional reference. This study is part of the CEBA-project (Chronic fatigue following acute Epstein-Barr virus infection in adolescents).

RESULTS

In the final multiple linear regression model, fatigue six months after acute EBV infection was significantly and independently predicted by the following baseline variables (regression coefficient B[95% CI]): Sensory sensitivity (0.8[0.09-1.6]), pain severity (0.2[0.02-0.3]), functional impairment (1000 steps/day) (-0.3[-0.5 to -0.08]), negative emotions (anxiety) (0.4[0.2-0.6]), verbal memory (correct word recognition) (1.7[0.1-3.3]), plasma C-reactive protein (2.8[1.1-4.4] for CRP values >0.86) and plasma Vitamin B₁₂ (-0.005[-0.01 to -0.001]).

CONCLUSIONS

Development of fatigue after acute EBV infection is to a larger extent predicted by baseline variables related to symptoms and functions than to baseline variables reflecting infectious and immune processes.

TRIAL REGISTRATION

ClinicalTrials, ID: NCT02335437, https://clinicaltrials.gov/ct2/show/NCT02335437.

Circadian rhythm abnormalities and autonomic dysfunction in patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) patients frequently show autonomic symptoms which may be associated with a hypothalamic dysfunction. This study aimed to explore circadian rhythm patterns in rest and activity and distal skin temperature (DST) and their association with self-reported outcome measures, in CFS/ME patients and healthy controls at two different times of year. Ten women who met both the 1994 CDC/Fukuda definition and 2003 Canadian criteria for CFS/ME were included in the study, along with ten healthy controls matched for age, sex and body mass index. Self-reported measures were used to assess fatigue, sleep quality, anxiety and depression, autonomic function and health-related quality of life. The ActTrust actigraph was used to record activity, DST and light intensity, with data intervals of one minute over seven consecutive days. Sleep variables were obtained through actigraphic analysis and from subjective sleep diary. The circadian variables and the spectral analysis of the rhythms were calculated. Linear regression analysis was used to evaluate the relationship between the rhythmic variables and clinical features. Recordings were taken in the same subjects in winter and summer. Results showed no differences in rhythm stability, sleep latency or number of awakenings between groups as measured with the actigraph. However, daily activity, the relative amplitude and the stability of the activity rhythm were lower in CFS/ME patients than in controls. DST was sensitive to environmental temperature and showed lower nocturnal values in CFS/ME patients than controls only in winter. A spectral analysis showed no differences in phase or amplitude of the 24h rhythm, but the power of the second harmonic (12h), revealed differences between groups (controls showed a post-lunch dip in activity and peak in DST, while CFS/ME patients did not) and correlated with clinical features. These findings suggest that circadian regulation and skin vasodilator responses may play a role in CFS/ME.