Evidence browser

E2 ModerateCohortPEM not requiredObservational

Metabolic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Not Due to Anti-mitochondrial Antibodies.

Nilsson, Isabell, Palmer, Jeremy, Apostolou, Eirini et al.·Frontiers in medicine·2020

Researchers tested whether ME/CFS patients have immune system antibodies that attack their mitochondria (the energy-producing parts of cells), similar to what happens in a different disease called primary biliary cholangitis. They found that ME/CFS patients almost never have these specific antibodies, while patients with the other disease have them consistently. This suggests that the energy problems seen in ME/CFS are caused by something other than the immune system attacking mitochondria.

Energy Metabolism

Breathing pattern disorders (dysfunctional breathing) characteristics and outcomes of children and young people attending a secondary care respiratory clinic.

Newson, Timothy P, Elias, Annie·Pediatric pulmonology·2020

This study looked at 18 young people (ages 11-16) who had breathing pattern disorders—abnormal ways of breathing that caused problems like chest tightness, difficulty breathing during exercise, or feeling like their throat was closing. Most of these young people also had asthma, anxiety, or other conditions. When properly diagnosed and treated by a speech therapist, most improved significantly and felt more confident managing their symptoms, though it often took months to get the right diagnosis.

E2 ModerateBehavioralPEM not requiredObservational

Post-exertional malaise is associated with greater symptom burden and psychological distress in patients diagnosed with Chronic Fatigue Syndrome.

May, Marcella, Milrad, Sara F, Perdomo, Dolores M et al.·Journal of psychosomatic research·2020

This study compared people with ME/CFS who experience severe post-exertional malaise (PEM—getting much worse after activity) with those who experience mild PEM. People with severe PEM reported more intense symptoms, greater disruption to their daily lives and social activities, and higher levels of depression and mood problems. Importantly, people in both groups had similarly stressful life experiences, suggesting that PEM severity itself—not just general stress—drives these differences.

Autonomic Phenotypes in Chronic Fatigue Syndrome (CFS) Are Associated with Illness Severity: A Cluster Analysis.

Słomko, Joanna, Estévez-López, Fernando, Kujawski, Sławomir et al.·Journal of clinical medicine·2020

This study looked at 131 ME/CFS patients to see if different types of autonomic nervous system problems (the system that controls heart rate, blood pressure, and digestion) exist. Researchers found four distinct patterns: some patients had sympathetic overactivity with dysfunction, some had sympathetic symptoms alone, some had parasympathetic issues, and some had an imbalance between the two systems. Patients with sympathetic overactivity had the most severe symptoms and worst quality of life, while those with balanced autonomic function were younger, less fatigued, and reported better quality of life.

E2 ModerateReviewPEM unclearReview-Narrative

Phytotherapy for Cachexia: Where Do We Stand?

Kuchta, Kenny, Cameron, Silke·Frontiers in pharmacology·2020

This review examines herbal medicines used in Japan and Russia to treat cachexia—a condition of muscle loss, weight loss, and fatigue. The researchers found that three traditional plant-based preparations (Hochuekkito, Juzentaihoto, and Rikkunshito) showed promise in clinical studies for reducing fatigue, increasing weight, and improving overall health in patients with cancer, COPD, dementia, and chronic fatigue syndrome. Since no approved medications currently exist for cachexia in Western medicine, the authors suggest these herbal treatments deserve further research and potential use in Europe and North America.

Pain and SensitizationSleepCognitive Impairment

Health-related quality of life in patients with myalgic encephalomyelitis/chronic fatigue syndrome: an Australian cross-sectional study.

Eaton-Fitch, N, Johnston, S C, Zalewski, P et al.·Quality of life research : an international journal of quality of life aspects of treatment, care and rehabilitation·2020

This Australian study of 480 people with ME/CFS found that the condition severely impacts quality of life across all major areas—physical functioning, emotional well-being, pain, and energy levels. People with ME/CFS scored much lower on quality of life measures compared to the general population, with the lowest scores for physical activities and fatigue. The study identified specific symptoms like cognitive difficulties, sleep problems, and cardiovascular issues that are most strongly linked to reduced quality of life.

E2 ModerateCohortPEM unclearObservational

Cognitive Function Declines Following Orthostatic Stress in Adults With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

van Campen, C Linda M C, Rowe, Peter C, Verheugt, Freek W A et al.·Frontiers in neuroscience·2020

This study found that people with ME/CFS experience significant problems with memory and thinking speed after their body has been stressed by a tilt test (a medical test that checks how the body handles position changes). Specifically, when tested right after the tilt procedure, patients made more mistakes on memory tasks and responded much more slowly compared to before the test. This suggests that the physical stress of orthostatic intolerance directly worsens cognitive problems in ME/CFS.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Health Conditions and Psychotic Experiences: Cross-Sectional Findings From the American Life Panel.

Oh, Hans, Smith, Lee, Koyanagi, Ai·Frontiers in psychiatry·2020

This study looked at whether people who experience psychotic symptoms (like unusual beliefs or perceptions) also tend to have more physical health problems. Researchers surveyed a representative group of American adults and found that people reporting lifetime psychotic experiences were more likely to have conditions like chronic fatigue syndrome, chronic pain, sleep disorders, migraines, and gastrointestinal problems. The more health conditions someone had, the stronger the association with psychotic experiences.

Pain and SensitizationSleep

E2 ModerateBehavioralPEM not requiredObservational

Posttraumatic Stress Disorder and Chronic Pain Conditions in Men: A Twin Study.

Gasperi, Marianna, Panizzon, Matthew, Goldberg, Jack et al.·Psychosomatic medicine·2020

This study looked at whether trauma-related stress (PTSD) and chronic pain conditions share common causes in twins. Using data from nearly 5,000 male twins, researchers found that both genetics and life experiences contribute to why people with PTSD often also develop chronic pain. The study suggests these two problems frequently occur together because they share some of the same underlying risk factors.

Maximal handgrip strength can predict maximal physical performance in patients with chronic fatigue.

Jammes, Yves, Stavris, Chloé, Charpin, Caroline et al.·Clinical biomechanics (Bristol, Avon)·2020

Researchers tested whether hand grip strength could predict how well patients with ME/CFS could exercise on a stationary bike. They found that patients with stronger hand grip were able to exercise harder and use more oxygen. This suggests that a simple hand grip test might help doctors understand a patient's exercise capacity without needing expensive equipment.

Reductions in Cerebral Blood Flow Can Be Provoked by Sitting in Severe Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients.

Campen, C Linda Mc van, Rowe, Peter C, Visser, Frans C·Healthcare (Basel, Switzerland)·2020

This study tested whether a simple sitting test could detect blood flow problems in the brains of severely ill ME/CFS patients. Researchers found that 90% of severe ME/CFS patients had significant drops in brain blood flow when sitting upright—dropping by about 24.5%—while healthy people's brain blood flow barely changed. This sitting test was easier to tolerate than standard tilt tests and could be useful for diagnosing blood flow problems in the most severely affected patients.

E2 ModerateBehavioralPEM unclearObservational

Guided graded Exercise Self-help for chronic fatigue syndrome: patient experiences and perceptions.

Cheshire, Anna, Ridge, Damien, Clark, Lucy et al.·Disability and rehabilitation·2020

This study looked at what patients experienced when they tried a guided exercise self-help program (GES) for ME/CFS. Some patients improved while others got worse. The researchers found that people who improved tended to be more motivated and faced fewer obstacles, while those who worsened had been sick longer, had other health conditions, and experienced symptom flare-ups from the exercise. The study suggests that the booklet alone isn't enough—patients need support from healthcare professionals who understand ME/CFS, especially during the difficult early weeks when improvements haven't started yet.

E2 ModerateCohortPEM not requiredObservational

Hospital Records of Pain, Fatigue, or Circulatory Symptoms in Girls Exposed to Human Papillomavirus Vaccination: Cohort, Self-Controlled Case Series, and Population Time Trend Studies.

Thomsen, Reimar Wernich, Öztürk, Buket, Pedersen, Lars et al.·American journal of epidemiology·2020

This large Danish study looked at whether the HPV vaccine (which prevents cervical cancer) was linked to symptoms like pain, fatigue, or heart problems in girls. Researchers compared vaccinated and unvaccinated girls over 14 years and found no increase in hospital visits for these symptoms in vaccinated girls. The symptoms they tracked increased over time in both vaccinated and unvaccinated children, suggesting other factors were responsible.

Pain in adolescent chronic fatigue following Epstein-Barr virus infection.

Brodwall, Elias Myrstad, Pedersen, Maria, Asprusten, Tarjei Tørre et al.·Scandinavian journal of pain·2020

This study looked at pain symptoms in teenagers who developed chronic fatigue after a common virus infection (Epstein-Barr virus). Researchers compared teenagers who had the virus and became fatigued, those who had the virus but did not become fatigued, and healthy teenagers without the virus. They found that the fatigued group reported significantly more pain symptoms and that the amount of pain they experienced was strongly linked to their quality of life.

Pain and Sensitization

Functional gastrointestinal disorders are increased in joint hypermobility-related disorders with concomitant postural orthostatic tachycardia syndrome.

Tai, Foong Way David, Palsson, Olafur S, Lam, Ching Y et al.·Neurogastroenterology and motility·2020

This study looked at people with joint hypermobility disorders (including Ehlers-Danlos syndrome) to understand how often they experience stomach and digestive problems. The researchers found that those who also have POTS (a condition affecting heart rate and blood pressure when standing) had significantly more digestive issues than those without POTS. The digestive problems remained worse in the POTS group even after accounting for other conditions like chronic fatigue syndrome.

Cytokine profiling of extracellular vesicles isolated from plasma in myalgic encephalomyelitis/chronic fatigue syndrome: a pilot study.

Giloteaux, Ludovic, O'Neal, Adam, Castro-Marrero, Jesús et al.·Journal of translational medicine·2020

This study looked at tiny particles called extracellular vesicles (EVs) in the blood of ME/CFS patients and compared them to healthy people. The researchers found that ME/CFS patients had more of these small particles, and the chemical messengers (cytokines) inside and around them showed unusual patterns of interaction that differed from healthy controls. This suggests that immune system signaling may be working differently in ME/CFS.

Immune System

Paradigm shift to disequilibrium in the genesis of orthostatic intolerance in patients with myalgic encephalomyelitis and chronic fatigue syndrome.

Miwa, Kunihisa, Inoue, Yukichi·International Journal of Cardiology. Hypertension·2020

This study looked at why people with ME/CFS struggle to stand up without feeling dizzy or unsteady. Researchers tested 72 patients and found that balance problems while standing (disequilibrium) were much more common in those who couldn't complete a 10-minute standing test than previously thought. The study suggests that poor balance, rather than just heart rate problems, may be a main reason why standing is so difficult for many ME/CFS patients.

E2 ModerateCohortPEM not requiredCase-Control

Health-related quality of life in Norwegian adolescents living with chronic fatigue syndrome.

Similä, Wenche Ann, Halsteinli, Vidar, Helland, Ingrid B et al.·Health and quality of life outcomes·2020

This study measured how ME/CFS affects the quality of life of teenagers in Norway. Researchers found that adolescents with ME/CFS reported significantly lower quality of life compared to healthy peers, with boys reporting better outcomes than girls. Having support from teachers, attending school, participating in activities, and avoiding depression were linked with better quality of life.

Reduced heart rate variability predicts fatigue severity in individuals with chronic fatigue syndrome/myalgic encephalomyelitis.

Escorihuela, Rosa María, Capdevila, Lluís, Castro, Juan Ramos et al.·Journal of translational medicine·2020

This study measured how the heart rate varies between beats in people with ME/CFS compared to healthy people. Researchers found that people with ME/CFS have less variation in their heart rate and that this reduced variation is connected to how severe their fatigue is. The findings suggest that an overactive stress response in the nervous system may contribute to fatigue severity.

Hemodynamics during the 10-minute NASA Lean Test: evidence of circulatory decompensation in a subset of ME/CFS patients.

Lee, Jihyun, Vernon, Suzanne D, Jeys, Patricia et al.·Journal of translational medicine·2020

This study tested a simple 10-minute standing test called the NASA Lean Test in ME/CFS patients to understand heart and blood vessel problems that cause dizziness and weakness. Researchers found that patients who became sick more recently (within 4 years) showed signs of circulation problems during the test—their hearts beat faster and their blood pressure changed abnormally—while those sick for over 10 years showed fewer of these changes. The NASA Lean Test appears to be a useful tool that doctors can use to diagnose and monitor these circulation problems.