Systematic review of fatigue severity in ME/CFS patients: insights from randomized controlled trials

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a debilitating illness medically unexplained, affecting approximately 1% of the global population. Due to the subjective complaint, assessing the exact severity of fatigue is a clinical challenge, thus, this study aimed to produce comprehensive features of fatigue severity in ME/CFS patients.

Methods: We systematically extracted the data for fatigue levels of participants in randomized controlled trials (RCTs) targeting ME/CFS from PubMed, Cochrane Library, Web of Science, and CINAHL throughout January 31, 2024. We normalized each different measurement to a maximum 100-point scale and performed a meta-analysis to assess fatigue severity by subgroups of age, fatigue domain, intervention, case definition, and assessment tool, respectively.

Results: Among the total of 497 relevant studies, 60 RCTs finally met our eligibility criteria, which included a total of 7088 ME/CFS patients (males 1815, females 4532, and no information 741). The fatigue severity of the whole 7,088 patients was 77.9 (95% CI 74.7-81.0), showing 77.7 (95% CI 74.3-81.0) from 54 RCTs in 6,706 adults and 79.6 (95% CI 69.8-89.3) from 6 RCTs in 382 adolescents. Regarding the domain of fatigue, ‘cognitive’ (74.2, 95% CI 65.4-83.0) and ‘physical’ fatigue (74.3, 95% CI 68.3-80.3) were a little higher than ‘mental’ fatigue (70.1, 95% CI 64.4-75.8). The ME/CFS participants for non-pharmacological intervention (79.1, 95% CI 75.2-83.0) showed a higher fatigue level than those for pharmacological intervention (75.5, 95% CI 70.0-81.0). The fatigue levels of ME/CFS patients varied according to diagnostic criteria and assessment tools adapted in RCTs, likely from 54.2 by ICC (International Consensus Criteria) to 83.6 by Canadian criteria and 54.2 by MFS (Mental Fatigue Scale) to 88.6 by CIS (Checklist Individual Strength), respectively.

Conclusions: This systematic review firstly produced comprehensive features of fatigue severity in patients with ME/CFS. Our data will provide insights for clinicians in diagnosis, therapeutic assessment, and patient management, as well as for researchers in fatigue-related investigations.

Source: Park JW, Park BJ, Lee JS, Lee EJ, Ahn YC, Son CG. Systematic review of fatigue severity in ME/CFS patients: insights from randomized controlled trials. J Transl Med. 2024 Jun 3;22(1):529. doi: 10.1186/s12967-024-05349-7. PMID: 38831460; PMCID: PMC11145935. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11145935/ (Full text)

Examining well-being and cognitive function in people with long Covid and ME/CFS, and age-matched healthy controls: A Case-Case-Control Study

Abstract:

Purpose: Well-being and cognitive function had not previously been compared between people with long COVID and people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Therefore, this study examined well-being and cognitive function in people with long COVID (∼16 months illness duration; n= 17) and ME/CFS (∼16 years illness duration; n=24), versus age-matched healthy controls (n=16).

Methods: Well-being was examined using several questionnaires, namely the Health Visual Analogue Scale (VAS), Fatigue Severity Scale (FSS), Post-exertional malaise (PEM), Pittsburgh Sleep Quality Index (PSQI), European Quality of Life-5 Domains (EQ-5D), MRC Dyspnoea, Self-Efficacy (SELTC), The Edinburgh Neurosymptoms Questionnaire (ENS), General Anxiety Disorder 7 (GAD-7), and Patient Health Questionnaire 9 (PHQ-9). Cognitive function was examined using Single Digit Modalities Test (SDMT), Stroop test, and Trails A and B. These were delivered via a mobile application (app) built specifically for this remote data collection.

Results: The main findings of the present investigation were that people with ME/CFS and people with long COVID were generally comparable on all well-being and cognitive function measures, but self-reported worse values for pain, fatigue, Post-exertional malaise, sleep quality, general well-being in relation to mobility, usual activities, self-care, breathlessness, neurological symptoms, self-efficacy, and other well-being such as anxiety and depression, compared to controls. There was no effect of group for cognitive function measures.

Conclusions: These data suggest that both people with long COVID and people with ME/CFS have similar impairment on well-being measures examined herein. Therefore, interventions that target well-being of people with ME/CFS and long COVID are required.

Source: Sanal-Hayes NEM, Mclaughlin M, Hayes LD, Berry ECJ, Sculthorpe NF. Examining well-being and cognitive function in people with long Covid and ME/CFS, and age-matched healthy controls: A Case-Case-Control Study. Am J Med. 2024 May 13:S0002-9343(24)00273-0. doi: 10.1016/j.amjmed.2024.04.041. Epub ahead of print. PMID: 38750713. https://www.amjmed.com/article/S0002-9343(24)00273-0/fulltext (Full text)

Actigraphic and Genetic Characterization of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Phenotypes in the UK Biobank (P10-9.007)

Abstract:

Objective: Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) often experience debilitating fatigue and autonomic dysregulation, yet objective measurements of these symptoms are limited. This study utilized actigraphic data from the United Kingdom Biobank (UKBB) to investigate (1) reduced activity in those with CFS, (2) decreased amplitudes of daily temperature rhythms as a potential indicator of autonomic dysregulation, and (3) the impact of specific single nucleotide polymorphisms (SNPs) associated with CFS on these actigraphic parameters.

Background: ME/CFS is a complex and poorly understood condition characterized by profound fatigue, postural orthostasis, and temperature dysregulation. Objective metrics reflecting these fatigue-related symptoms are scarce. Previous research explored small-scale actigraphic analyses, shedding light on movement and temperature patterns in CFS, but large-scale investigations remain limited. Genetic factors have also emerged as potential contributors to CFS risk, although how they affect phenotypic manifestations remains unclear.

Design/Methods: Actigraphic data from the UKBB were analyzed to compare those with CFS (n = 295) to controls (n = 63,133). Movement parameters, acceleration amplitudes, and temperature amplitudes were assessed. Additionally, the impact of specific SNPs associated with CFS on actigraphic measurements and subjective fatigue experiences was examined.

Results: In addition to profound fatigue, those with CFS exhibited significantly reduced overall movement (Cohen’s d = −0.220, p-value = 2.42 × 10–15), lower acceleration amplitudes (Cohen’s d = −0.377, p-value = 1.74 × 10−6), and decreased temperature amplitudes (Cohen’s d = −0.173, p-value = 0.002) compared to controls. Furthermore, certain SNPs associated with CFS were found to significantly influence both actigraphic measurements and subjective fatigue experiences.

Conclusions: This study provides valuable insights into the objective characterization of CFS using actigraphy, shedding light on the interaction between genetics and symptomatology in CFS. The findings offer avenues for further research into the pathophysiology of CFS and may contribute to a better understanding of fatigue-related conditions in general.

Source: Patrick Liu, David Raizen, Carsten Skarke, Thomas Brooks, and Ron Anafi. Actigraphic and Genetic Characterization of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Phenotypes in the UK Biobank (P10-9.007). Neurology, April 9, 2024 issue
102 (17_supplement_1) https://doi.org/10.1212/WNL.0000000000204829 https://www.neurology.org/doi/abs/10.1212/WNL.0000000000204829

The influence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) family history on patients with ME/CFS

Abstract:

Aim: It is unclear if individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) with family histories of ME/CFS differ from those with ME/CFS without this family history. To explore this issue, quantitative data from patients with ME/CFS and controls were collected, and we examined those with and without family histories of ME/CFS.

Methods: The samples included 400 patients with ME/CFS, and a non-ME/CFS chronic illness control group of 241 patients with multiple sclerosis (MS) and 173 with post-polio syndrome (PPS).

Results: Confirming findings from prior studies, those with ME/CFS were more likely to have family members with ME/CFS than controls. We found family histories of ME/CFS were significantly higher (18%) among the ME/CFS group than the non-ME/CFS controls (3.9%). In addition, patients with ME/CFS who had family histories of ME/CFS were more likely to have gastrointestinal symptoms than those with ME/CFS without those family histories.

Conclusions: Given the recent reports of gastrointestinal difficulties among those with ME/CFS, our findings might represent one predisposing factor for the emergence of ME/CFS.
Source: Jason LA, Ngonmedje S. The influence of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) family history on patients with ME/CFS. Explor Med. 2024;5:185–92. https://doi.org/10.37349/emed.2024.00215 https://www.explorationpub.com/Journals/em/Article/1001215 (Full text)

Research progress in the treatment of chronic fatigue syndrome through interventions targeting the hypothalamus-pituitary-adrenal axis

Abstract:

Chronic fatigue syndrome (CFS) causes great harm to individuals and society. Elucidating the pathogenesis of CFS and developing safe and effective treatments are urgently needed. This paper reviews the functional changes in the hypothalamus-pituitary-adrenal (HPA) axis in patients with CFS and the associated neuroendocrine mechanisms. Despite some controversy, the current mainstream research evidence indicates that CFS patients have mild hypocortisolism, weakened daily variation in cortisol, a weakened response to the HPA axis, and an increase in negative feedback of the HPA axis. The relationship between dysfunction of the HPA axis and the typical symptoms of CFS are discussed, and the current treatment methods are reviewed.

Source: Yi-Dan Zhang, Li-Na Wang. Research progress in the treatment of chronic fatigue syndrome through interventions targeting the hypothalamus-pituitary-adrenal axis. Front. Endocrinol., 09 April 2024, Sec. Neuroendocrine Science, Volume 15 – 2024 | https://doi.org/10.3389/fendo.2024.1373748 https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1373748/full

Do people with ME/CFS and joint hypermobility represent a disease subgroup? An analysis using registry data

Abstract:

Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a chronic, multifaceted disease that affects millions globally. Despite its significant impact, the disease’s etiology remains poorly understood, and symptom heterogeneity poses challenges for diagnosis and treatment. Joint hypermobility, commonly seen in hypermobile Ehlers-Danlos Syndrome (hEDS), has been observed in ME/CFS patients but its prevalence and clinical significance within this population are not well-characterized.

Objective: To compare the characteristics of ME/CFS patients with and without joint hypermobility (JH+ and JH-) as assessed using the Beighton scoring system, and to explore whether JH+ ME/CFS patients exhibit distinct disease characteristics, comorbidities, and health-related quality of life (HRQOL).

Methods: The study used cross-sectional, self-reported data from 815 participants of the You + ME Registry. Participants were categorized as JH+ or JH- based on self–assessed Beighton scores and compared across demographics, comorbidities, family history, and symptoms. HRQOL was assessed using the Short Form-36 RAND survey and Karnofsky Performance Status.

Results: 15.5% (N = 126) of participants were classified as JH+. JH+ participants were more likely to be female, report Ehlers-Danlos Syndrome (EDS), Postural Orthostatic Tachycardia Syndrome (POTS), and a family history of EDS. They experienced worse HRQOL, particularly in physical functioning and pain, and a higher number of autonomic, neurocognitive, headache, gut, and musculoskeletal symptoms. Sensitivity analysis suggested that ME/CFS with concurrent JH+ and EDS was associated with more severe symptoms and greater functional impairment.

Conclusion: ME/CFS patients with joint hypermobility, particularly those with EDS, demonstrate distinct clinical characteristics, including more severe symptomatology and reduced HRQOL. These findings highlight the need for comprehensive clinical assessments of ME/CFS patients with joint hypermobility. Understanding these relationships could aid in subgroup identification, improving diagnosis, and informing targeted therapeutic approaches. Further research is warranted to explore these associations and their implications for clinical practice.

Source: Kathleen Mudie, Allison Ramiller, Sadie Whittaker, Leslie E. Phillips. Do people with ME/CFS and joint hypermobility represent a disease subgroup? An analysis using registry data. Front. Neurol., 12 March 2024, Sec. Autonomic Disorders, Volume 15 – 2024 | https://doi.org/10.3389/fneur.2024.1324879 https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2024.1324879/full (Full text)

The effect of comorbid medical diagnoses on disturbed sleep in chronic fatigue syndrome

Abstract:

Background: Chronic fatigue syndrome [CFS] may occur alone or with fibromyalgia. This has led some to believe the two occur along a common illness spectrum. Evaluating whether this is the case is important as differences in burden or severity of CFS with fibromyalgia (FM) would suggest different underlying pathophysiological processes.

Objective: To determine if Insomnia Severity Index [ISI] scores differ between patients with CFS and those with CFS plus FM. In addition, we aim to determine if insomnia severity is impacted by other comorbid medically unexplained diagnoses.

Methods: 247 patients with CFS completed the ISI and the Centers for Epidemiological Study – Depression. Patient groups were stratified on CFS severity and the presence of FM. A secondary analysis was conducted to evaluate insomnia severity related to the number of comorbid medically unexplained diagnoses including, FM, multiple chemical sensitivity and/or irritable bowel syndrome.

Results: When controlling for depressed mood, ISI did not differ significantly across patient groups defined by CFS severity and FM status. However, independent of mood, ISI was sensitive to multiple diagnoses showing a significant increasing trend from CFS alone to CFS plus one, two or three comorbid diagnoses.

Conclusion: Although CFS severity and FM status do not impact insomnia severity, increased illness burden as manifested by multiple medically unexplained diagnoses does appear to influence insomnia. In contrast to our earlier studies, this study did not find that a comorbid diagnosis of FM in patients with CFS is related to a worse outcome in the variable of interest.

Source: Aaron J. StegnerMichelle Blate & Benjamin H. Natelson (2024) The effect of comorbid medical diagnoses on disturbed sleep in chronic fatigue syndrome, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2024.2322915 https://www.tandfonline.com/doi/full/10.1080/21641846.2024.2322915

Heterogeneity in Measures of Illness among Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Is Not Explained by Clinical Practice: A Study in Seven U.S. Specialty Clinics

Abstract:

Background: One of the goals of the Multi-site Clinical Assessment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (MCAM) study was to evaluate whether clinicians experienced in diagnosing and caring for patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) recognized the same clinical entity.
Methods: We enrolled participants from seven specialty clinics in the United States. We used baseline data (n = 465) on standardized questions measuring general clinical characteristics, functional impairment, post-exertional malaise, fatigue, sleep, neurocognitive/autonomic symptoms, pain, and other symptoms to evaluate whether patient characteristics differed by clinic.
Results: We found few statistically significant and no clinically significant differences between clinics in their patients’ standardized measures of ME/CFS symptoms and function. Strikingly, patients in each clinic sample and overall showed a wide distribution in all scores and measures.
Conclusions: Illness heterogeneity may be an inherent feature of ME/CFS. Presenting research data in scatter plots or histograms will help clarify the challenge. Relying on case–control study designs without subgrouping or stratification of ME/CFS illness characteristics may limit the reproducibility of research findings and could obscure underlying mechanisms.
Source: Unger ER, Lin J-MS, Chen Y, Cornelius ME, Helton B, Issa AN, Bertolli J, Klimas NG, Balbin EG, Bateman L, et al. Heterogeneity in Measures of Illness among Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Is Not Explained by Clinical Practice: A Study in Seven U.S. Specialty Clinics. Journal of Clinical Medicine. 2024; 13(5):1369. https://doi.org/10.3390/jcm13051369 https://www.mdpi.com/2077-0383/13/5/1369 (Full text)

Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome

Abstract:

Background: Fatigue of unknown origin is a hallmark symptom in chronic fatigue syndrome (CFS) and is also found in 20% of hypothyroidism patients despite appropriate levothyroxine treatment. Here, we suggest that in these disorders, peripheral serotonin levels are low, and elevating them to normal range with L-carnitine is accompanied with reduced fatigue.

Methods: We conducted a retrospective analysis of follow-up clinical data (CFS N=12; hypothyroidism with fatigue N=40) where serum serotonin and fatigue levels were compared before vs. after 7 weeks of oral L-carnitine supplementation.

Results: After L-carnitine, serotonin increased (8-fold in CFS, Sig. = 0.002, 6-fold in hypothyroidism, Sig. < 0.001) whereas fatigue decreased (2-fold in both CFS and hypothyroidism, Sig. = 0.002 for CFS, Sig. < 0.001 for hypothyroidism). There was a negative correlation between serotonin level and fatigue (for CFS, rho = -0.49 before and -0.67 after L-carnitine; for hypothyroidism, rho = -0.24 before and -0.83 after L-carnitine).

Conclusions: These findings suggest a new link between low peripheral serotonin, L-carnitine, and fatigue.

Source: Tommi Raij, Kari Raij. Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome. Front. Endocrinol. Sec. Neuroendocrine Science, Volume 15 – 2024 | doi: 10.3389/fendo.2024.1358404 https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2024.1358404/abstract

The Head-Up Tilt Table Test as a Measure of Autonomic Functioning among Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) often experience autonomic symptoms. In the present study, we evaluated 193 adults seeking treatment for ME/CFS, who were recruited from an outpatient clinic. The participants completed a head-up tilt table test to assess two common types of orthostatic intolerance, namely, postural orthostatic tachycardia syndrome (POTS) and orthostatic hypotension (OH).
During the tilt test, 32.5% of the participants demonstrated POTS or OH. The participants with either of these two common types of orthostatic intolerance were found to have more problems with sleep and post-exertional malaise as assessed by the DePaul Symptom Questionnaire; these patients also reported more physical and health function limitations. The implications of the findings are discussed.
Source: Jason LA, McGarrigle WJ, Vermeulen RCW. The Head-Up Tilt Table Test as a Measure of Autonomic Functioning among Patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Journal of Personalized Medicine. 2024; 14(3):238. https://doi.org/10.3390/jpm14030238 https://www.mdpi.com/2075-4426/14/3/238 (Full text)