ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

341–360 of 742 studies

E2 ModerateCohortPEM not requiredCross-Sectional

Transforming growth factor beta (TGF-β) in adolescent chronic fatigue syndrome.

Wyller, Vegard Bruun, Nguyen, Chinh Bkrong, Ludviksen, Judith Anita et al.·Journal of translational medicine·2017

This study tested whether a protein called TGF-β, which helps regulate immune and stress responses, was elevated in adolescents with ME/CFS. Researchers compared blood levels of TGF-β in 120 young ME/CFS patients to 68 healthy controls and found the protein levels were actually the same in both groups. However, they discovered that in ME/CFS patients, TGF-β levels were connected to stress hormones and fatigue severity, suggesting it may play a role in how the illness affects the body even if it's not simply 'too high.'

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Post-Exertional Malaise in Patients with ME and CFS with Comorbid Fibromyalgia.

McManimen, Stephanie L, Jason, Leonard A·SRL neurology & neurosurgery·2017

This study looked at how having fibromyalgia (FM) alongside ME/CFS affects post-exertional malaise (PEM)—the worsening of symptoms after physical or mental activity. Researchers surveyed people online about their PEM symptoms and found that those with both conditions experienced more severe and frequent PEM symptoms than those with ME/CFS alone, particularly affecting muscle pain and overall fatigue. The findings suggest that having fibromyalgia as an additional diagnosis makes ME/CFS symptoms significantly worse.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredObservational

Current Safety Concerns with Human Papillomavirus Vaccine: A Cluster Analysis of Reports in VigiBase®.

Chandler, Rebecca E, Juhlin, Kristina, Fransson, Jonas et al.·Drug safety·2017

Researchers analyzed thousands of reports from a global database of side effects following HPV vaccination. They found that certain combinations of symptoms—headaches, dizziness, fatigue, and fainting—were reported more often after HPV vaccination than with other vaccines, particularly in young women. These symptom clusters resemble conditions like POTS, CRPS, and chronic fatigue syndrome, though most reports did not include an official diagnosis.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM not requiredCase-Control

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: case-control study.

Clark, L V, Buckland, M, Murphy, G et al.·Clinical and experimental immunology·2017

This study examined whether people with ME/CFS have abnormal immune protein levels (cytokines) in their blood, especially after physical activity. Researchers compared 24 ME/CFS patients with 21 healthy controls and measured multiple immune markers at rest and after exercise. The study found no significant differences in immune protein levels between the two groups, and no link between post-exertional symptoms and increased cytokine levels.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Murdock, Kyle W, Wang, Xin Shelley, Shi, Qiuling et al.·Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation·2017

Researchers tested three common questionnaires that measure fatigue and symptoms in ME/CFS patients to see which ones work best. They found that two popular questionnaires had problems—many patients scored so high they hit the ceiling (meaning the test couldn't measure if they got worse), and the questions weren't reliable. The DePaul Symptom Questionnaire worked much better, especially at measuring post-exertional malaise (the worsening of symptoms after activity), and could reliably distinguish ME/CFS patients from healthy people.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCase-Control

The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Healthy People.

Oosterwijck, Jessica Van, Marusic, Uros, De Wandele, Inge et al.·Pain physician·2017

This study looked at why exercise doesn't reduce pain in people with ME/CFS the way it normally does in healthy people. Researchers measured how the nervous system recovered after exercise and tracked pain levels in 20 women with ME/CFS and 20 healthy women. They found that people with ME/CFS had problems with their nervous system's ability to 'turn off' after exercise, and this was connected to their pain not improving like it should.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Differences in ME and CFS Symptomology in Patients with Normal and Abnormal Exercise Test Results.

McManimen, Stephanie L, Jason, Leonard A·International journal of neurology and neurotherapy·2017

This study looked at ME/CFS patients who had different results after exercise testing. Some patients showed abnormal test results and experienced severe post-exertional malaise (PEM)—that exhaustion and symptom flare-up after activity—while others had normal test results with milder PEM. The researchers found that patients with abnormal test results tended to be more disabled, experience worse PEM, and were more likely to be bedbound than those with normal results.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands.

Collin, Simon M, Nikolaus, Stephanie, Heron, Jon et al.·Journal of psychosomatic research·2016

This study looked at how ME/CFS symptoms vary from person to person by analyzing data from over 8,000 patients in the UK and Netherlands. Researchers found that ME/CFS patients fall into about 6 different groups based on which symptoms they experience—some have many symptoms, some mainly have pain, and others have very few symptoms beyond the core three (fatigue, brain fog, and sleep problems). Women and people who have been ill longer tended to have more symptoms overall.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome.

Pendergrast, Tricia, Brown, Abigail, Sunnquist, Madison et al.·Chronic illness·2016

This study compared ME/CFS patients who are severely ill and mostly confined to their homes with those who are less severely affected and can leave home. Researchers found that the housebound group—about 1 in 4 patients—experienced much worse physical functioning, fatigue, pain, brain fog, sleep problems, and other symptoms compared to the less severely ill group. Understanding these differences can help doctors and researchers better tailor treatments for the most severely affected patients.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearCase-Control

Association of biomarkers with health-related quality of life and history of stressors in myalgic encephalomyelitis/chronic fatigue syndrome patients.

Fenouillet, Emmanuel, Vigouroux, Aude, Steinberg, Jean Guillaume et al.·Journal of translational medicine·2016

This study examined blood markers and muscle function in 36 ME/CFS patients compared to 11 healthy controls to understand whether biological changes relate to symptoms and quality of life. Researchers found three key differences: problems with muscle response to exercise, increased oxidative stress (cellular damage), and changes in immune cells. These biomarkers correlated with how much ME/CFS affected patients' daily lives, especially in those whose illness started after a severe infection.

Immune SystemPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Case definitions integrating empiric and consensus perspectives.

Jason, Leonard A, McManimen, Stephanie, Sunnquist, Madison et al.·Fatigue : biomedicine, health & behavior·2016

This study looked at 556 ME/CFS patients from three countries to understand how doctors should diagnose this condition. The researchers found that patients fall into different groups based on their symptoms: some have chronic fatigue alone, some have fatigue with other medical reasons, and some have ME/CFS with additional symptoms like problems with exercise recovery, brain fog, and sleep issues. The groups with more specific ME/CFS symptoms were significantly more disabled than those with just general fatigue.

SleepPost-Exertional Malaise

E2 ModerateCohortPEM requiredObservational

Changes in Gut and Plasma Microbiome following Exercise Challenge in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Shukla, Sanjay K, Cook, Dane, Meyer, Jacob et al.·PloS one·2015

This study examined whether the bacteria living in the gut of ME/CFS patients behave differently after exercise compared to healthy people. Researchers collected stool and blood samples from 10 ME/CFS patients and 10 healthy controls before and after an intense exercise test. They found that after exercise, ME/CFS patients showed unusual changes in their gut bacteria and had more bacterial DNA circulating in their blood 72 hours later—something that didn't happen in healthy people.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Examining the Institute of Medicine's Recommendations Regarding Chronic Fatigue Syndrome: Clinical Versus Research Criteria.

Jason, Leonard A, McManimen, Stephanie, Sunnquist, Madison et al.·Journal of neurology and psychology·2015

This study compared two different sets of diagnostic criteria for ME/CFS: one proposed by the Institute of Medicine for clinical use, and another (the Canadian criteria) recommended for research. Using patient data from the US, UK, and Norway, researchers found that patients meeting the research criteria were significantly more severely affected across multiple symptoms and daily functioning areas. This suggests the two criteria sets identify somewhat different groups of patients.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Timed loaded standing in female chronic fatigue syndrome compared with other populations.

Eyskens, Jan B, Nijs, Jo, D'Août, Kristiaan et al.·Journal of rehabilitation research and development·2015

Researchers tested how long women with ME/CFS could hold small weights with their arms extended straight out—a test that measures muscle endurance in the arms and trunk. Women with ME/CFS performed significantly worse than healthy women and even worse than older women with osteoporosis, suggesting a specific weakness pattern in ME/CFS. This finding could help guide rehabilitation programs that focus on movement quality rather than just building strength.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis.

Jason, Leonard A, Evans, Meredyth, Brown, Abigail et al.·Journal of prevention & intervention in the community·2015

This study looked at whether using a specific definition of ME (sudden onset myalgic encephalomyelitis) identifies a sicker group of patients compared to the broader CFS (chronic fatigue syndrome) definition. Researchers found that people who met the ME criteria had more severe symptoms, greater disability, and worse post-exertional malaise (feeling much worse after physical activity) than those meeting only the CFS criteria. The findings suggest that the ME definition may identify patients with more serious illness.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains.

Jason, Leonard A, Sunnquist, Madison, Brown, Abigail et al.·Journal of neurology and neurobiology·2015

Researchers analyzed symptom patterns in people with ME/CFS from three countries to better understand what makes this illness unique. Using statistical analysis, they found that ME/CFS symptoms naturally organize into four main groups: exhaustion that gets worse after activity, brain fog and memory problems, sleep issues, and a combination of hormone, nervous system, and immune problems. This organized way of thinking about symptoms could help doctors recognize and study the disease more effectively.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Chronic Fatigue Syndrome versus Systemic Exertion Intolerance Disease.

Jason, Leonard A, Sunnquist, Madison, Brown, Abigail et al.·Fatigue : biomedicine, health & behavior·2015

Researchers compared different ways of diagnosing ME/CFS by testing 796 patients using a new diagnostic system called SEID (Systemic Exertion Intolerance Disease). They found that the new SEID criteria identified about 88% of patients, which is similar to an older diagnostic system but captures a larger group than some other definitions. The study suggests that different diagnostic criteria can identify different sizes and severity levels of patient populations.

Cognitive ImpairmentPost-Exertional Malaise

E2 ModerateCohortPEM requiredCross-Sectional

Chronic Fatigue Syndrome and Myalgic Encephalomyelitis: Toward An Empirical Case Definition.

Jason, Leonard A, Kot, Bobby, Sunnquist, Madison et al.·Health psychology and behavioral medicine·2015

Researchers studied which symptoms are most important for diagnosing ME/CFS by comparing patients with the condition to people without it. They found that four main symptoms stood out: extreme fatigue, symptom worsening after activity (called post-exertional malaise), thinking or memory problems, and sleep that doesn't feel refreshing. Using these core symptoms could help doctors diagnose ME/CFS more reliably.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredObservational

Fatigue in adults with post-infectious fatigue syndrome: a qualitative content analysis.

Stormorken, Eva, Jason, Leonard A, Kirkevold, Marit·BMC nursing·2015

This study interviewed 26 adults with ME/CFS about their fatigue to better understand what they experience. The researchers found that fatigue in ME/CFS is not just tiredness—it's a complex, all-consuming symptom that gets much worse with even small activities and is accompanied by other symptoms like brain fog and pain. The fatigue also changes throughout the day and is triggered by physical activity, emotions, stress, and sometimes things patients don't even realize are triggering it.

Post-Exertional Malaise

E2 ModerateCohortPEM requiredCase-Control

Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case-control study.

Miller, Ruth R, Reid, W Darlene, Mattman, Andre et al.·Journal of translational medicine·2015

This study tested whether a simple hand-squeezing exercise combined with a special infrared light tool could help identify ME/CFS in patients. Researchers compared 16 people with ME/CFS to 16 healthy people and measured how well oxygen was being used in their muscles during the test. People with ME/CFS showed different patterns of oxygen use and reported feeling more tired during the exercise, even though they were squeezing with less force.

BiomarkersPost-Exertional Malaise

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Transforming growth factor beta (TGF-β) in adolescent chronic fatigue syndrome.

Post-Exertional Malaise in Patients with ME and CFS with Comorbid Fibromyalgia.

Current Safety Concerns with Human Papillomavirus Vaccine: A Cluster Analysis of Reports in VigiBase®.

Cytokine responses to exercise and activity in patients with chronic fatigue syndrome: case-control study.

The utility of patient-reported outcome measures among patients with myalgic encephalomyelitis/chronic fatigue syndrome.

The Role of Autonomic Function in Exercise-induced Endogenous Analgesia: A Case-control Study in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Healthy People.

Differences in ME and CFS Symptomology in Patients with Normal and Abnormal Exercise Test Results.

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands.

Housebound versus nonhousebound patients with myalgic encephalomyelitis and chronic fatigue syndrome.

Association of biomarkers with health-related quality of life and history of stressors in myalgic encephalomyelitis/chronic fatigue syndrome patients.

Case definitions integrating empiric and consensus perspectives.

Changes in Gut and Plasma Microbiome following Exercise Challenge in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Examining the Institute of Medicine's Recommendations Regarding Chronic Fatigue Syndrome: Clinical Versus Research Criteria.

Timed loaded standing in female chronic fatigue syndrome compared with other populations.

Chronic fatigue syndrome versus sudden onset myalgic encephalomyelitis.

Factor Analysis of the DePaul Symptom Questionnaire: Identifying Core Domains.

Chronic Fatigue Syndrome versus Systemic Exertion Intolerance Disease.

Chronic Fatigue Syndrome and Myalgic Encephalomyelitis: Toward An Empirical Case Definition.

Fatigue in adults with post-infectious fatigue syndrome: a qualitative content analysis.

Submaximal exercise testing with near-infrared spectroscopy in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome patients compared to healthy controls: a case-control study.

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