ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

301–320 of 6,157 studies

E0 ConsensusReviewPEM not requiredMeta-Analysis

Heart rate variability in patients with somatic symptom disorders and functional somatic syndromes: A systematic review and meta-analysis.

Ying-Chih, Cheng, Yu-Chen, Huang, Wei-Lieh, Huang·Neuroscience and biobehavioral reviews·2020

This large review combined results from 85 studies comparing heart rhythm patterns between people with conditions like fibromyalgia and ME/CFS (functional somatic syndromes) and healthy people. Researchers found that patients with these conditions have lower heart rate variability—meaning their heart's rhythm is less flexible and adaptive—which suggests their nervous system may not be responding normally to stress and daily activities.

Autonomic Nervous System

E0 ConsensusReviewPEM not requiredReview-Narrative

Food Implications in Central Sensitization Syndromes.

Aguilar-Aguilar, Elena, Marcos-Pasero, Helena, Ikonomopoulou, Maria P et al.·Journal of clinical medicine·2020

This review examined what is known about how food affects three related conditions—fibromyalgia, ME/CFS, and multiple chemical sensitivities—that all involve heightened nervous system sensitivity. The authors found that changing diet can help improve quality of life for many patients, but the best approach is personalized and done with help from a dietitian and doctor. They warn against following strict diets without professional guidance.

E0 ConsensusReviewPEM not requiredSystematic-Review

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

Lim, Eun-Jin, Ahn, Yo-Chan, Jang, Eun-Su et al.·Journal of translational medicine·2020

This study looked at 45 research projects involving over 1 million people to estimate how many people have ME/CFS worldwide. The researchers found that about 0.68% of the general population (roughly 1 in 150 people) has ME/CFS, though the number varies depending on who was studied and how the diagnosis was made. Women are about 1.5 to 2 times more likely to have ME/CFS than men.

Diagnostics

E0 ConsensusReviewPEM unclearSystematic-Review

Systematic Review of Primary Outcome Measurements for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in Randomized Controlled Trials.

Kim, Do-Young, Lee, Jin-Seok, Son, Chang-Gue·Journal of clinical medicine·2020

This study examined how researchers measure treatment effects in ME/CFS clinical trials by reviewing 52 studies published between 1996 and 2020. The researchers found that most trials rely on patient questionnaires asking about fatigue, physical function, and quality of life rather than objective blood tests or physical measurements. Three questionnaires—the SF-36, Checklist Individual Strength, and Chalder Fatigue Questionnaire—were used most often to track whether treatments worked.

E0 ConsensusReviewPEM not requiredSystematic-Review

A systematic review on the health outcomes associated with non-endocarditis manifestations of chronic Q fever.

Manchal, Naveen, Adegboye, Oyelola A, Eisen, Damon P·European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology·2020

This study looked at chronic Q fever, a bacterial infection that can cause long-term complications beyond heart valve infections. Researchers found that when chronic Q fever affects bones, blood vessels, or causes abscesses (pockets of infection), patients experience significantly more pain than other forms of the disease. Importantly, the study reviewed existing research to understand how pain and fatigue appear in these less common forms of chronic Q fever.

Pain and Sensitization

E0 ConsensusReviewPEM unclearReview-Narrative

Environmental, Neuro-immune, and Neuro-oxidative Stress Interactions in Chronic Fatigue Syndrome.

Bjørklund, Geir, Dadar, Maryam, Pivina, Lyudmila et al.·Molecular neurobiology·2020

This review looked at how ME/CFS develops by examining immune system problems, oxidative stress (cellular damage from harmful molecules), infections, and nutritional issues. Researchers found that people with ME/CFS often have changes in their immune cells and proteins, along with signs of cellular damage that could explain fatigue, pain, and other symptoms. The study suggests that treatments targeting oxidative stress and nutrition might help, though more research is needed.

Immune SystemPost-Exertional Malaise

E0 ConsensusReviewPEM not requiredReview-Narrative

Complex syndromes of chronic pain, fatigue and cognitive impairment linked to autoimmune dysautonomia and small fiber neuropathy.

Shoenfeld, Yehuda, Ryabkova, Varvara A, Scheibenbogen, Carmen et al.·Clinical immunology (Orlando, Fla.)·2020

This review brings together evidence suggesting that ME/CFS, along with related conditions like POTS and complex regional pain syndrome, may share a common autoimmune root cause. The researchers found that these conditions are linked by similar patterns: the body's immune system produces antibodies that attack certain nerve receptors, and small nerve fibers become damaged. By understanding these shared mechanisms, doctors may eventually be able to better identify which patients would benefit from immune-targeting treatments.

Immune System

E0 ConsensusReviewPEM requiredSystematic-Review

Review of case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Lim, Eun-Jin, Son, Chang-Gue·Journal of translational medicine·2020

This study reviewed how ME/CFS has been defined and diagnosed over the past 34 years, examining 25 different case definitions created by researchers. The researchers found that these definitions fall into four main categories and emphasize different key symptoms—some focus on a viral cause, others on inflammation, and some on multiple system problems. Understanding these different approaches helps doctors and patients recognize that ME/CFS is complex and may require more than one way to diagnose it.

Cognitive ImpairmentPost-Exertional Malaise

E0 ConsensusReviewPEM not requiredSystematic-Review

Systematic Review and Meta-analysis of Postlicensure Observational Studies on Human Papillomavirus Vaccination and Autoimmune and Other Rare Adverse Events.

Willame, Corinne, Gadroen, Kartini, Bramer, Wichor et al.·The Pediatric infectious disease journal·2020

Researchers reviewed 22 studies that tracked the safety of HPV vaccines (which prevent certain cancers) in millions of people after the vaccines were approved for use. They looked specifically at whether these vaccines were linked to autoimmune diseases—conditions where the immune system attacks the body. Overall, they found no clear connection between HPV vaccines and most rare diseases, though a few associations (both positive and negative) were noted.

E0 ConsensusReviewPEM requiredSystematic-Review

Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

Davenport, Todd E, Lehnen, Mary, Stevens, Staci R et al.·Frontiers in pediatrics·2019

This review examines how people with ME/CFS respond to exercise differently than healthy people. Researchers found that during exercise tests, people with ME/CFS have a blunted heart rate response—their heart rate doesn't increase as much as expected for the amount of work they're doing. This abnormal response, called chronotropic intolerance, may help explain why exercise worsens symptoms in ME/CFS patients.

Post-Exertional Malaise

E0 ConsensusReviewPEM not requiredSystematic-Review

General medical services by non-medical health professionals: a systematic quantitative review of economic evaluations in primary care.

Anthony, Bethany F, Surgey, Alun, Hiscock, Julia et al.·The British journal of general practice : the journal of the Royal College of General Practitioners·2019

This review looked at whether nurses, pharmacists, and other healthcare professionals can provide medical care more cheaply than doctors in primary care settings. The researchers found very limited evidence about costs and outcomes, with some nurse-led care for minor problems being cost-effective, but nurse-led care for chronic fatigue syndrome was not cost-effective compared to doctor care.

E0 ConsensusReviewPEM not requiredSystematic-Review

Identification of mental health and quality of life outcomes in primary care databases in the UK: a systematic review.

Carreira, Helena, Williams, Rachael, Strongman, Helen et al.·BMJ open·2019

Researchers reviewed 120 studies that used UK patient medical records to track mental health and quality of life problems like depression, anxiety, fatigue, and cognitive issues. They found that different studies used different definitions and coding systems to identify these conditions, making it hard to compare results across studies. The authors recommend that researchers agree on standard definitions and validated code lists so findings are more consistent and reliable.

Pain and SensitizationSleepCognitive Impairment

E0 ConsensusReviewPEM not requiredSystematic-Review

Post-bacterial infection chronic fatigue syndrome is not a latent infection.

Melenotte, Cléa, Drancourt, Michel, Gorvel, Jean Pierre et al.·Medecine et maladies infectieuses·2019

This review examined whether bacteria that stay dormant (inactive) in the body after an infection could cause chronic fatigue syndrome symptoms. The researchers looked at scientific evidence and found no proof that dormant bacteria cause the ongoing fatigue and other symptoms people experience after bacterial infections. The study suggests that psychological trauma and unknown causes may play a role in post-infection fatigue, rather than persistent bacterial infection.

E0 ConsensusReviewPEM unclearMeta-Analysis

Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and meta-analysis.

Nelson, Maximillian J, Bahl, Jasvir S, Buckley, Jonathan D et al.·Medicine·2019

This study looked at how the hearts of people with ME/CFS respond differently compared to healthy people, focusing on heart rate and its patterns. Researchers reviewed 64 previous studies and found that ME/CFS patients tend to have higher resting heart rates, unusual heart rate responses to position changes, and different patterns in heart rate variability (the natural variation in time between heartbeats). These findings suggest that the nervous system that controls heart function may work differently in people with ME/CFS.

Autonomic Nervous System

E0 ConsensusReviewPEM not requiredSystematic-Review

Cognitive behavioural therapy for myalgic encephalomyelitis/chronic fatigue syndrome is not effective. Re-analysis of a Cochrane review.

Vink, Mark, Vink-Niese, Alexandra·Health psychology open·2019

This study reviewed research on cognitive behavioural therapy (CBT) for ME/CFS and found that it helps only a small number of patients with mild symptoms experience temporary subjective fatigue improvement. The improvement didn't translate into better physical fitness, job status, or disability benefits. Safety concerns were largely unreported in the original studies, but patient reports suggest about 1 in 5 people experienced negative outcomes.

Interventions

E0 ConsensusReviewPEM unclearSystematic-Review

Epigenetic Components of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Uncover Potential Transposable Element Activation.

Almenar-Pérez, Eloy, Ovejero, Tamara, Sánchez-Fito, Teresa et al.·Clinical therapeutics·2019

This study reviewed research on how ME/CFS may involve changes in how genes are regulated, not the genes themselves. The researchers discovered that dormant DNA sequences called transposable elements—which make up almost half of our genome and were previously thought to be 'junk DNA'—might become activated in ME/CFS patients. This activation could trigger the immune system to attack without an actual infection present.

Immune System

E0 ConsensusReviewPEM requiredReview-Narrative

[Myalgic encephalomyelitis or chronic fatigue syndrome].

Brinth, Louise, Nielsen, Henrik, Varming, Kim et al.·Ugeskrift for laeger·2019

ME/CFS is a serious condition that causes extreme tiredness affecting both mind and body, along with pain, sleep problems, difficulty thinking clearly, and a symptom called post-exertional malaise where activity makes symptoms worse. Research has found changes in patients' cells, hormones, immune systems, and how their bodies process energy, which could lead to better ways to diagnose and treat this condition.

BiomarkersEnergy MetabolismImmune SystemPost-Exertional Malaise

E0 ConsensusReviewPEM unclearReview-Narrative

How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?

Nacul, Luis, Lacerda, Eliana M, Kingdon, Caroline C et al.·Journal of health psychology·2019

This study examines why ME/CFS research has been inconsistent and controversial. The main problem is that doctors and researchers use different definitions to diagnose ME/CFS, which means different groups of patients are studied in different research projects. The authors explain how using clearer, more consistent diagnostic criteria could help researchers better understand the disease and make progress in finding treatments.

Diagnostics

E0 ConsensusReviewPEM not requiredReview-Narrative

Anti-Inflammatory Diets and Fatigue.

Haß, Ulrike, Herpich, Catrin, Norman, Kristina·Nutrients·2019

This review looked at whether eating anti-inflammatory foods—like whole grains, vegetables rich in plant compounds, and omega-3 fatty acids—might help reduce fatigue in people with chronic illnesses. The researchers examined 21 human studies and found that while single nutrients alone showed mixed results, eating a balanced diet with these whole foods showed promise for improving fatigue. However, more research is still needed to confirm these findings.

E0 ConsensusReviewPEM unclearMeta-Analysis

Peak Oxygen Uptake in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Meta-Analysis.

Franklin, John Derek, Atkinson, Greg, Atkinson, Janet M et al.·International journal of sports medicine·2019

This research review analyzed 32 studies comparing how much oxygen people with ME/CFS can use during maximum exercise compared to healthy people. On average, people with ME/CFS used about 5 milliliters less oxygen per kilogram of body weight per minute than healthy controls—a meaningful difference that likely affects real-world functioning. This reduced oxygen capacity is one of the measurable physical differences between ME/CFS patients and healthy individuals.

Post-Exertional Malaise

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Evidence browser

Heart rate variability in patients with somatic symptom disorders and functional somatic syndromes: A systematic review and meta-analysis.

Food Implications in Central Sensitization Syndromes.

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

Systematic Review of Primary Outcome Measurements for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) in Randomized Controlled Trials.

A systematic review on the health outcomes associated with non-endocarditis manifestations of chronic Q fever.

Environmental, Neuro-immune, and Neuro-oxidative Stress Interactions in Chronic Fatigue Syndrome.

Complex syndromes of chronic pain, fatigue and cognitive impairment linked to autoimmune dysautonomia and small fiber neuropathy.

Review of case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

Systematic Review and Meta-analysis of Postlicensure Observational Studies on Human Papillomavirus Vaccination and Autoimmune and Other Rare Adverse Events.

Chronotropic Intolerance: An Overlooked Determinant of Symptoms and Activity Limitation in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome?

General medical services by non-medical health professionals: a systematic quantitative review of economic evaluations in primary care.

Identification of mental health and quality of life outcomes in primary care databases in the UK: a systematic review.

Post-bacterial infection chronic fatigue syndrome is not a latent infection.

Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome: A systematic review and meta-analysis.

Cognitive behavioural therapy for myalgic encephalomyelitis/chronic fatigue syndrome is not effective. Re-analysis of a Cochrane review.

Epigenetic Components of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Uncover Potential Transposable Element Activation.

[Myalgic encephalomyelitis or chronic fatigue syndrome].

How have selection bias and disease misclassification undermined the validity of myalgic encephalomyelitis/chronic fatigue syndrome studies?

Anti-Inflammatory Diets and Fatigue.

Peak Oxygen Uptake in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A Meta-Analysis.

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Neuroinflammation Evidence

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Biomarkers

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