Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)

Abstract:

BACKGROUND: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) has been emerging as a significant health issue worldwide. This study aimed to systemically assess the prevalence of CFS/ME in various aspects of analyses for precise assessment.

METHODS: We systematically searched prevalence of CFS/ME from public databases from 1980 to December 2018. Data were extracted according to 7 categories for analysis: study participants, gender and age of the participants, case definition, diagnostic method, publication year, and country of the study conducted. Prevalence data were collected and counted individually for studies adopted various case definitions. We analyzed and estimated prevalence rates in various angles: average prevalence, pooled prevalence and meta-analysis of all studies.

RESULTS: A total of 1291 articles were initially identified, and 45 articles (46 studies, 56 prevalence data) were selected for this study. Total 1085,976 participants were enrolled from community-based survey (540,901) and primary care sites (545,075). The total average prevalence was 1.40 ± 1.57%, pooled prevalence 0.39%, and meta-analysis 0.68% [95% CI 0.48-0.97]. The prevalence rates were varied by enrolled participants (gender, study participants, and population group), case definitions and diagnostic methods. For example, in the meta-analysis; women (1.36% [95% CI 0.48-0.97]) vs. men (0.86% [95% CI 0.48-0.97]), community-based samples (0.76% [95% CI 0.53-1.10]) vs. primary care sites (0.63% [95% CI 0.37-1.10]), adults ≥ 18 years (0.65% [95% CI 0.43-0.99]) vs. children and adolescents < 18 years (0.55% [95% CI 0.22-1.35]), CDC-1994 (0.89% [95% CI 0.60-1.33]) vs. Holmes (0.17% [95% CI 0.06-0.49]), and interviews (1.14% [95% CI 0.76-1.72]) vs. physician diagnosis (0.09% [95% CI 0.05-0.13]), respectively.

CONCLUSIONS: This study comprehensively estimated the prevalence of CFS/ME; 0.89% according to the most commonly used case definition CDC-1994, with women approximately 1.5 to 2 folds higher than men in all categories. However, we observed the prevalence rates are widely varied particularly by case definitions and diagnostic methods. An objective diagnostic tool is urgently required for rigorous assessment of the prevalence of CFS/ME.

Source: Lim EJ, Ahn YC, Jang ES, Lee SW, Lee SH, Son CG. Systematic review and meta-analysis of the prevalence of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). J Transl Med. 2020 Feb 24;18(1):100. doi: 10.1186/s12967-020-02269-0. https://www.ncbi.nlm.nih.gov/pubmed/32093722

Systematic review of randomized controlled trials for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME)

Abstract:

BACKGROUND: Although medical requirements are urgent, no effective intervention has been proven for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). To facilitate the development of new therapeutics, we systematically reviewed the randomized controlled trials (RCTs) for CFS/ME to date.

METHODS: RCTs targeting CFS/ME were surveyed using two electronic databases, PubMed and the Cochrane library, through April 2019. We included only RCTs that targeted fatigue-related symptoms, and we analyzed the data in terms of the characteristics of the participants, case definitions, primary measurements, and interventions with overall outcomes.

RESULTS: Among 513 potentially relevant articles, 55 RCTs met our inclusion criteria; these included 25 RCTs of 22 different pharmacological interventions, 28 RCTs of 18 non-pharmacological interventions and 2 RCTs of combined interventions. These studies accounted for a total of 6316 participants (1568 males and 4748 females, 5859 adults and 457 adolescents). CDC 1994 (Fukuda) criteria were mostly used for case definitions (42 RCTs, 76.4%), and the primary measurement tools included the Checklist Individual Strength (CIS, 36.4%) and the 36-item Short Form health survey (SF-36, 30.9%). Eight interventions showed statistical significance: 3 pharmacological (Staphypan Berna, Poly(I):poly(C12U) and CoQ10 + NADH) and 5 non-pharmacological therapies (cognitive-behavior-therapy-related treatments, graded-exercise-related therapies, rehabilitation, acupuncture and abdominal tuina). However, there was no definitely effective intervention with coherence and reproducibility.

CONCLUSIONS: This systematic review integrates the comprehensive features of previous RCTs for CFS/ME and reflects on their limitations and perspectives in the process of developing new interventions.

Source: Kim DY, Lee JS, Park SY, Kim SJ, Son CG. Systematic review of randomized controlled trials for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). J Transl Med. 2020 Jan 6;18(1):7. doi: 10.1186/s12967-019-02196-9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943902/ (Full article)

Inflammatory proteins are altered in chronic fatigue syndrome-A systematic review and meta-analysis

Abstract:

Immune dysfunction has been posited as a key element in the aetiology of chronic fatigue syndrome (CFS) since the illness was first conceived. However, systematic reviews have yet to quantitatively synthesise inflammatory biomarkers across the literature. We undertook a systematic review and meta-analysis to quantify available data on circulating inflammatory proteins, examining studies recruiting patients with a CFS diagnosis and a non-affected control group. Results were meta-analysed from 42 studies.

Patients with CFS had significantly elevated tumour necrosis factor (ES = 0.274, p < 0.001), interleukin-2 (ES = 0.203, p = 0.006), interleukin-4 (ES = 0.373, p = 0.004), transforming growth factor-β (ES = 0.967, p < 0.001) and c-reactive protein (ES = 0.622, p = 0.019). 12 proteins did not differ between groups.

These data provide some support for an inflammatory component in CFS, although inconsistency of results indicates that inflammation is unlikely to be a primary feature in all those suffering from this disorder. It is hoped that further work will elucidate whether there are subgroups of patients with clinically-relevant inflammatory dysfunction, and whether inflammatory cytokines may provide a prognostic biomarker or moderate treatment effects.

Copyright © 2019. Published by Elsevier Ltd.

Source: Strawbridge R, Sartor ML, Scott F, Cleare AJ. Inflammatory proteins are altered in chronic fatigue syndrome-A systematic review and meta-analysis. Neurosci Biobehav Rev. 2019 Aug 26;107:69-83. doi: 10.1016/j.neubiorev.2019.08.011. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31465778

A systematic review of cytokines in chronic fatigue syndrome/myalgic encephalomyelitis/systemic exertion intolerance disease (CFS/ME/SEID)

Abstract:

BACKGROUND: Cytokines in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis/Systemic Exertion Intolerance Disease (CFS/ME/SEID) patients compared with healthy controls have been extensively studied. However, the evidence regarding whether a baseline difference between CFS/ME/SEID patients and the normal population remains unclear. The aim of this study was to conduct a systematic review of the literature regarding cytokines in CFS/ME/SEID and whether there is a significant difference in cytokine levels between this patient group and the normal population.

METHODS: Pubmed, Scopus, Medline (EBSCOHost), and EMBASE databases were searched to source relevant studies for CFS/ME/SEID. The review included any studies examining cytokines in CFS/ME/SEID patients compared with healthy controls. Results of the literature search were summarised according to aspects of their study design and outcome measures, namely, cytokines. Quality assessment was also completed to summarise the level of evidence available.

RESULTS: A total of 16,702 publications were returned using our search terms. After screening of papers according to our inclusion and exclusion criteria, 15 studies were included in the review. All the included studies were observational case control studies. Ten of the studies identified measured serum cytokines in CFS/ME/SEID patients, and four measured cytokines in other physiological fluids of CFS/ME/SEID patients. The overall quality assessment revealed most papers included in this systematic review to be consistent.

CONCLUSIONS: Despite the availability of moderate quality studies, the findings of this review are inconclusive as to whether cytokines play any definitive role in CFS/ME/SEID, and consequently, they would not serve as reliable biomarkers. Therefore, in light of these results, it is recommended that further efforts toward a diagnostic test and treatment for CFS/ME/SEID continue to be developed in a range of research fields.

Source: Corbitt M, Eaton-Fitch N, Staines D, Cabanas H, Marshall-Gradisnik S. A systematic review of cytokines in chronic fatigue syndrome/myalgic encephalomyelitis/systemic exertion intolerance disease (CFS/ME/SEID). BMC Neurol. 2019 Aug 24;19(1):207. doi: 10.1186/s12883-019-1433-0. https://bmcneurol.biomedcentral.com/articles/10.1186/s12883-019-1433-0 (Full article)

Acupuncture for chronic fatigue syndrome: a systematic review and meta-analysis

Abstract:

OBJECTIVE: To evaluate evidence for the efficacy of acupuncture for chronic fatigue syndrome (CFS).

METHODS: Randomized controlled trials (RCTs) comparing acupuncture with sham acupuncture, other interventions that may have a therapeutic effect, or no intervention, for the treatment of CFS, were searched for in the following databases up to March 2018: Pubmed; Embase; the Cochrane Library; Web of Science; Wanfang database; China National Knowledge Infrastructure (CNKI); Chinese Biomedicine (CBM) database; and VIP database. Risk of bias was determined using the Cochrane tool. Meta-analyses were performed using RevMan V.5.3 software. The GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) was adopted for levels of evidence.

RESULTS: Sixteen studies with 1346 subjects were included. Most studies had low methodological quality. Meta-analyses showed a favourable effect of acupuncture on overall response rate compared with sham acupuncture (four studies, 281 participants, RR=2.08, 95% CI 1.4 to 3.1, I2=64%, low certainty) and Chinese herbal medicine (three studies, 290 participants, RR=1.17, 95% CI 1.07 to 1.29, I2=0%, low certainty). Acupuncture also appeared to significantly reduce fatigue severity measured by Chalder’s Fatigue Scale and the Fatigue Severity Scale compared with other types of control.

CONCLUSION: Our review indicated that acupuncture was more effective than sham acupuncture and other interventions (Chinese herbal medicine, mainly), but no firm conclusion could be reached owing to limited data, poor quality and potentially exaggerated effect size evaluation. Further large, rigorously designed and reported RCTs are required.

Source: Zhang Q, Gong J, Dong H, Xu S, Wang W, Huang G. Acupuncture for chronic fatigue syndrome: a systematic review and meta-analysis. Acupunct Med. 2019 Jun 17:acupmed2017011582. doi: 10.1136/acupmed-2017-011582. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31204859

Assessment of the scientific rigour of randomized controlled trials on the effectiveness of cognitive behavioural therapy and graded exercise therapy for patients with myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review

Abstract:

Cognitive behavioural therapy and graded exercise therapy have been promoted as effective treatments for patients with myalgic encephalomyelitis/chronic fatigue syndrome. However, criticism on the scientific rigour of these studies has been raised. This review assessed the methodological quality of studies on the effectiveness of cognitive behavioural therapy and graded exercise therapy. The methodological quality of the 18 included studies was found to be relatively low, as bias was prominently found, affecting the main outcome measures of the studies (fatigue, physical functioning and functional impairment/status). Future research should focus on including more objective outcome measures in a well-defined patient population.

Source: Ahmed SA, Mewes JC, Vrijhoef H. Assessment of the scientific rigour of randomized controlled trials on the effectiveness of cognitive behavioural therapy and graded exercise therapy for patients with myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review. J Health Psychol. 2019 May 10:1359105319847261. doi: 10.1177/1359105319847261. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31072121

A systematic review of enteric dysbiosis in chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

BACKGROUND: Chronic fatigue syndrome or myalgic encephalomyelitis (CFS/ME) is an illness characterised by profound and pervasive fatigue in addition to a heterogeneous constellation of symptoms. The aetiology of this condition remains unknown; however, it has been previously suggested that enteric dysbiosis is implicated in the pathogenesis of CFS/ME. This review examines the evidence currently available for the presence of abnormal microbial ecology in CFS/ME in comparison to healthy controls, with one exception being probiotic-supplemented CFS/ME patients, and whether the composition of the microbiome plays a role in symptom causation.

METHODS: EMBASE, Medline (via EBSCOhost), Pubmed and Scopus were systematically searched from 1994 to March 2018. All studies that investigated the gut microbiome composition of CFS/ME patients were initially included prior to the application of specific exclusion criteria. The association between these findings and patient-centred outcomes (fatigue, quality of life, gastrointestinal symptoms, psychological wellbeing) are also reported.

RESULTS: Seven studies that met the inclusion criteria were included in the review. The microbiome composition of CFS/ME patients was compared with healthy controls, with the exception of one study that compared to probiotic-supplemented CFS/ME patients. Differences were reported in each study; however, only three were considered statistically significant, and the findings across all studies were inconsistent. The quality of the studies included in this review scored between poor (< 54%), fair (54-72%) and good (94-100%) using the Downs and Black checklist.

CONCLUSIONS: There is currently insufficient evidence for enteric dysbiosis playing a significant role in the pathomechanism of CFS/ME. Recommendations for future research in this field include the use of consistent criteria for the diagnosis of CFS/ME, reduction of confounding variables by controlling factors that influence microbiome composition prior to sample collection and including more severe cases of CFS/ME.

Source: Du Preez S, Corbitt M, Cabanas H, Eaton N, Staines D, Marshall-Gradisnik S. A systematic review of enteric dysbiosis in chronic fatigue syndrome/myalgic encephalomyelitis. Syst Rev. 2018 Dec 20;7(1):241. doi: 10.1186/s13643-018-0909-0. https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-018-0909-0 (Full article)

Prevalence and incidence of myalgic encephalomyelitis/chronic fatigue syndrome in Europe-the Euro-epiME study from the European network EUROMENE: a protocol for a systematic review

Abstract:

INTRODUCTION: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a chronic disease involving central nervous system and immune system disorders, as well as cardiovascular abnormalities. ME/CFS is characterised by severe chronic fatigue lasting for at least 6 months, including clinical symptoms such as tender cervical or axillary lymph nodes, muscle pain, joint pain without swelling or redness, post-exertional malaise for more than 24 hours and unrefreshing sleep. Studies on the epidemiology of ME/CFS in Europe only include single countries and, therefore, the prevalence and incidence of ME/CFS in Europe (as a whole) is unknown. One of the purposes of the European Network on ME/CFS (EUROMENE; European Union-funded COST Action; Reference number: 15111) is to address this gap in knowledge. We will systematically review the literature reporting figures from European countries to provide a robust summary and identify new challenges.

METHODS AND ANALYSIS: We will systematically search the literature databases Scopus, PubMed and Web of Science for studies published in the last 10 years (ie, after 2007). No language restriction will be applied. Two independent reviewers will search, screen and select studies as well as extract data about their main characteristics and evaluate their methodological and reporting quality. When disagreements emerge, the reviewers will discuss to reach a consensus. We plan to produce a narrative summary of our findings as we anticipate that studies are scarce and heterogeneous. The possibility of performing meta-analyses will be discussed in a EUROMENE meeting.

ETHICS AND DISSEMINATION: Ethical approval is not required as only publicly available data will be included. Findings will be described in EUROMENE reports, published in peer-reviewed journal(s) and presented at conferences. The findings will be also communicated to policy-makers, healthcare providers, people with ME/CFS and other sections of society through regular channels including the mass-media.

PROSPERO REGISTRATION NUMBER: CRD42017078688.

© Author(s) (or their employer(s)) 2018. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Source: Estévez-López F, Castro-Marrero J, Wang X, Bakken IJ, Ivanovs A, Nacul L, Sepúlveda N, Strand EB, Pheby D, Alegre J, Scheibenbogen C, Shikova E, Lorusso L, Capelli E, Sekulic S, Lacerda E, Murovska M; European Network on ME/CFS (EUROMENE). Prevalence and incidence of myalgic encephalomyelitis/chronic fatigue syndrome in Europe-the Euro-epiME study from the European network EUROMENE: a protocol for a systematic review. BMJ Open. 2018 Sep 4;8(9):e020817. doi: 10.1136/bmjopen-2017-020817. https://www.ncbi.nlm.nih.gov/pubmed/30181183