Evidence browser

E2 ModerateCohortPEM requiredCross-Sectional

Unsupervised Cluster Analysis Reveals Distinct Subtypes of ME/CFS Patients Based on Peak Oxygen Consumption and SF-36 Scores.

Lacasa, Marcos, Launois, Patricia, Prados, Ferran et al.·Clinical therapeutics·2023

This study examined whether oxygen consumption during an exercise test could help identify different types of ME/CFS patients. Researchers used questionnaire responses from 2,347 ME/CFS patients and then tested their findings in 92 patients who completed an exercise test. They found that patient responses on a quality-of-life survey directly matched up with how much oxygen their bodies could use during exercise, suggesting that low oxygen consumption may be a useful marker for identifying ME/CFS severity.

Biomarkers

Symptom-based clusters in people with ME/CFS: an illustration of clinical variety in a cross-sectional cohort.

Vaes, Anouk W, Van Herck, Maarten, Deng, Qichen et al.·Journal of translational medicine·2023

This study looked at whether people with ME/CFS can be grouped into different subtypes based on their specific combination of symptoms. Researchers asked 337 people with ME/CFS to report their symptoms and found 13 major groups, where people in each group shared similar patterns of symptom severity and frequency. While fatigue and post-exertional malaise (PEM) appeared in all groups, other symptoms varied—meaning people with ME/CFS experience the illness quite differently from one another.

Post-Exertional Malaise

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome in caregivers of children with cerebral palsy and affecting factors.

Pasin, Tugce, Karatekin, Bilinc Dogruoz, Pasin, Ozge·Northern clinics of Istanbul·2023

This study looked at mothers caring for children with cerebral palsy to see how many developed ME/CFS and what factors affected them. The researchers found that about 80% of the mothers met the clinical criteria for ME/CFS, with mothers who stayed home having more severe fatigue than those who worked full-time. The child's hand and arm function appeared to be an important factor in how severe the mother's fatigue became.

Sleep

Cytokine network analysis in a community-based pediatric sample of patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Jason, Leonard A, Gaglio, Caroline L, Furst, Jacob et al.·Chronic illness·2023

Researchers studied immune system chemicals called cytokines in children and teens with ME/CFS by comparing blood samples from sick patients and healthy controls. They found that children with ME/CFS had different patterns of these immune chemicals compared to healthy kids, with certain inflammatory markers being more active. This suggests ME/CFS involves real biological changes in how the immune system works, particularly in severe cases.

E2 ModerateBehavioralPEM not requiredLongitudinal

The association between the number of symptoms and the severity of Post-COVID-Fatigue after SARS-CoV-2 infection treated in an outpatient setting.

Schmidbauer, Lena, Kirchberger, Inge, Goßlau, Yvonne et al.·Journal of neurology·2023

This study looked at 425 people who had mild-to-moderate COVID-19 treated as outpatients and followed them for about 8 months afterward. Researchers found that 37% of these people developed long-lasting fatigue (Post-COVID-Fatigue), and those who had more symptoms during their initial infection and ongoing symptoms were more likely to experience severe fatigue. The more symptoms someone had, the worse their fatigue tended to be.

Cognitive Impairment

Uplifts and hassles are related to worsening in chronic fatigue syndrome: a prospective study.

Friedberg, Fred, Adamowicz, Jenna L, Bruckenthal, Patricia et al.·Journal of translational medicine·2023

This study tracked 128 ME/CFS patients over six months to see how daily pleasant and unpleasant events related to whether their illness got better, stayed the same, or got worse. Patients who worsened experienced more intense unpleasant events and had fewer pleasant events over time, while those who improved showed the opposite pattern. The findings suggest that the balance between daily hassles and uplifts may play a role in how ME/CFS progresses.

Risk factors for suicidal ideation in a chronic illness.

Elliott, Meghan K, Jason, Leonard A·Death studies·2023

This study looked at why some people with ME/CFS experience suicidal thoughts. Researchers surveyed 559 people with ME/CFS and found that certain factors—including sleep problems, feeling stigmatized by others, loss of physical abilities, severe disability, and being unmarried—were associated with increased suicide risk. The findings suggest that better education about ME/CFS, reducing stigma, and developing effective treatments could help protect people with this illness.

Sleep

E2 ModerateCohortPEM not requiredObservational

A cross-sectional study exploring the relationship between symptoms of anxiety/depression and P50 sensory gating in adult patients diagnosed with chronic fatigue syndrome/myalgic encephalomyelitis.

Liu, Xinyi, Liu, Sitong, Ren, Runtao et al.·Frontiers in neuroscience·2023

This study looked at 249 people with ME/CFS to understand how anxiety and depression relate to a specific brain activity pattern called P50 sensory gating. Researchers used questionnaires to measure anxiety and depression, and brain scans (EEG) to measure how well the brain filters out repetitive sounds. They found that abnormal filtering of sounds was linked to anxiety, depression, and fatigue severity.

The multi-generational familial aggregation of interstitial cystitis, other chronic nociplastic pain disorders, depression, and panic disorder.

Allen-Brady, Kristina, Fyer, Abby J, Weissman, Myrna·Psychological medicine·2023

This study found that interstitial cystitis (a chronic bladder pain condition) and several other conditions—including ME/CFS, fibromyalgia, irritable bowel syndrome, depression, and panic disorder—tend to run in families. Researchers looked at medical records and family trees of over a century of people in Utah to see if relatives of patients with these conditions had higher rates of the same or related conditions. They discovered that these six conditions share something in common genetically, meaning a family history of any one of them may increase the risk of developing others.

Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome.

van Eeden, Charmaine, Redmond, Desiree, Mohazab, Naima et al.·International journal of molecular sciences·2023

This study looked at people with a connective tissue disease called systemic sclerosis who also experience severe fatigue (ME/CFS symptoms). Researchers found that fatigued patients had different patterns in how their cells' energy-producing structures (mitochondria) work compared to non-fatigued patients. These differences involved specific genes related to energy production, suggesting that measuring these genes might help doctors identify which systemic sclerosis patients have ME/CFS.

Biomarkers

Autoantibodies to selenoprotein P in chronic fatigue syndrome suggest selenium transport impairment and acquired resistance to thyroid hormone.

Sun, Qian, Oltra, Elisa, Dijck-Brouwer, D A Janneke et al.·Redox biology·2023

Some people with ME/CFS have antibodies that attack a protein called selenoprotein P, which normally helps transport selenium (a mineral needed for thyroid function) throughout the body. This study found that ME/CFS patients with these antibodies have lower selenium levels and struggle to convert thyroid hormone into its active form, which could explain why they feel tired and have other thyroid-like symptoms even when standard thyroid tests appear normal.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Poor health-related quality of life in postural orthostatic tachycardia syndrome in comparison with a sex- and age-matched normative population.

Seeley, Marie-Claire, Gallagher, Celine, Ong, Eric et al.·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·2023

This study compared quality of life in people with POTS (a condition causing rapid heartbeat when standing) to people without POTS. Researchers found that people with POTS reported significantly worse quality of life across all areas tested, including mobility, self-care, daily activities, pain, and mood. The impact was consistent across all age groups, and was worse in people with severe symptoms, women, those with fatigue, and those who also had ME/CFS.

Autonomic Nervous System

A comparison of pain, fatigue, and function between post-COVID-19 condition, fibromyalgia, and chronic fatigue syndrome: a survey study.

Haider, Saman, Janowski, Adam J, Lesnak, Joseph B et al.·Pain·2023

This study surveyed 707 people with post-COVID-19, fibromyalgia, and/or ME/CFS to compare their symptoms. Researchers found that all three conditions share similar patterns of pain, fatigue, brain fog, anxiety, and depression that impact daily life. People with post-COVID-19 reported somewhat less severe pain and fatigue than those with fibromyalgia or ME/CFS, but those with multiple diagnoses had worse symptoms overall.

Pain and SensitizationCognitive Impairment

E2 ModerateBehavioralPEM not requiredCross-Sectional

Social position and functional somatic disorders: The DanFunD study.

Schovsbo, Signe U, Dantoft, Thomas M, Thuesen, Betina H et al.·Scandinavian journal of public health·2023

This study looked at whether people with lower social position—such as having less education, being unemployed, or living alone—are more likely to develop functional somatic disorders like ME/CFS, fibromyalgia, and IBS. The researchers found that people with lower social position did have higher rates of these conditions, and the effect was strongest for more severe cases. However, the study does not explain why this connection exists.

E2 ModerateCohortPEM requiredCross-Sectional

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study.

van Eeden, Charmaine, Mohazab, Naima, Redmond, Desiree et al.·Lancet regional health. Americas·2023

This study looked at fatigue in people with ANCA-vasculitis (a type of blood vessel inflammation) and found that over half met the diagnostic criteria for ME/CFS. The researchers discovered that the type of vasculitis matters: people with MPO-ANCA had fatigue patterns more similar to fibromyalgia, while those with PR3-ANCA had fatigue linked to inflammation markers. This suggests different types of vasculitis may cause fatigue through different biological mechanisms.

Serum GDF-15 Levels Accurately Differentiate Patients with Primary Mitochondrial Myopathy, Manifesting with Exercise Intolerance and Fatigue, from Patients with Chronic Fatigue Syndrome.

Bermejo-Guerrero, Laura, de Fuenmayor-Fernández de la Hoz, Carlos Pablo, Guerrero-Molina, María Paz et al.·Journal of clinical medicine·2023

This study tested whether a blood marker called GDF-15 could help doctors tell the difference between ME/CFS and a rare condition called primary mitochondrial myopathy (PMM), which affects how cells produce energy. Both conditions cause fatigue and exercise intolerance that can look very similar, but PMM requires different treatment. The researchers found that GDF-15 levels were very good at distinguishing between these two conditions, which could help patients get the right diagnosis faster without needing extensive genetic testing or muscle biopsies.

Diagnostics

Influence of Chronic Fatigue Syndrome Codiagnosis on the Relationship between Perceived and Objective Psychoneuro-Immunoendocrine Disorders in Women with Fibromyalgia.

Otero, Eduardo, Gálvez, Isabel, Ortega, Eduardo et al.·Biomedicines·2023

This study compared women with fibromyalgia (FM), some of whom also had been diagnosed with chronic fatigue syndrome (CFS), to healthy women. Researchers measured both what patients reported feeling (like stress and pain levels) and actual biological markers in their blood (like stress hormones and immune chemicals). They found that FM patients generally felt worse than healthy women, and their blood work matched this—showing higher stress hormones and lower mood-boosting chemicals. Interestingly, FM patients who also had a CFS diagnosis showed different blood markers than those with FM alone, suggesting these two conditions may overlap in ways that current diagnosis methods don't catch.

Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study.

Querec, Troy D, Lin, Jin-Mann S, Chen, Yang et al.·Journal of translational medicine·2023

Researchers tested whether a specific immune cell function called natural killer (NK) cytotoxicity could be a reliable blood test to help diagnose ME/CFS. They compared 174 people with ME/CFS to 86 healthy people and found no meaningful difference between the two groups. This means the test is not accurate enough to use in clinics right now, and scientists need to keep searching for better biological markers of ME/CFS.

Tryptophan catabolites, inflammation, and insulin resistance as determinants of chronic fatigue syndrome and affective symptoms in long COVID.

Al-Hakeim, Hussein Kadhem, Khairi Abed, Anwar, Rouf Moustafa, Shatha et al.·Frontiers in molecular neuroscience·2023

This study looked at 90 Long COVID patients and measured specific molecules in their blood related to how their body processes an amino acid called tryptophan. The researchers found that patients with the most severe Long COVID symptoms had low tryptophan levels and high levels of a related compound called kynurenine, along with markers of inflammation. These three measurements together explained about 40% of why patients had fatigue, pain, depression, and anxiety symptoms.

E2 ModerateCohortPEM unclearObservational

Observational Study of Repeat Immunoadsorption (RIA) in Post-COVID ME/CFS Patients with Elevated ß2-Adrenergic Receptor Autoantibodies-An Interim Report.

Stein, Elisa, Heindrich, Cornelia, Wittke, Kirsten et al.·Journal of clinical medicine·2023

This study tested a blood-cleaning procedure called immunoadsorption in 10 patients with ME/CFS that developed after COVID-19. The treatment removes harmful antibodies from the blood that may be attacking the body's nerve receptors. Seven patients showed meaningful improvement in physical function within four weeks, suggesting this approach may help some people with post-COVID ME/CFS.