Evidence browser

E2 ModerateBehavioralPEM not requiredCross-Sectional

The Relationship between Age and Illness Duration in Chronic Fatigue Syndrome.

Kidd, Elizabeth, Brown, Abigail, McManimen, Stephanie et al.·Diagnostics (Basel, Switzerland)·2016

This study looked at how age and how long someone has had ME/CFS might affect their symptoms and daily functioning. Researchers divided patients into four groups based on whether they were younger or older than 55, and whether they'd had the illness for more or less than 10 years. Interestingly, older patients who had lived with ME/CFS for over 10 years reported better mental health functioning than the other groups, while younger patients with longer illness duration experienced worse immune and nervous system symptoms compared to older patients with similar illness duration.

Factors determining fatigue in the chronic fatigue syndrome: a path analysis.

Tobback, Els, Hanoulle, Ignace, Mariman, An et al.·Acta clinica Belgica·2016

This study looked at how different factors—sleep quality, mood, and overall health—affect fatigue in ME/CFS patients. Researchers asked 167 patients to fill out questionnaires about their fatigue, sleep, personality traits, and quality of life. Surprisingly, they found that poor sleep directly harmed both physical and mental quality of life, but didn't necessarily increase fatigue scores on standard tests.

Sleep

E2 ModerateCohortPEM not requiredObservational

Reduced cardiac volumes in chronic fatigue syndrome associate with plasma volume but not length of disease: a cohort study.

Newton, Julia L, Finkelmeyer, Andreas, Petrides, George et al.·Open heart·2016

This study found that people with ME/CFS have smaller hearts and lower blood volumes than healthy people. Interestingly, these differences were not related to how long someone had been sick, suggesting the heart changes are not simply from being inactive. Patients with more severe fatigue tended to have lower plasma volume (the liquid part of blood), which might be a target for future treatment.

Autonomic Nervous System

E2 ModerateDiagnosticPEM not requiredMethods-Paper

Methods of applying the 1994 case definition of chronic fatigue syndrome - impact on classification and observed illness characteristics.

Unger, E R, Lin, J-M S, Tian, H et al.·Population health metrics·2016

Researchers tested two different ways of diagnosing ME/CFS using the same official criteria to see if the method mattered. One method asked patients direct questions about fatigue and symptoms, while the other used standardized questionnaires with scoring thresholds. They found that both methods identified similar people as having ME/CFS (about 82% agreement), but the questionnaire method identified somewhat more cases without them being less severely ill.

Diagnostics

E2 ModerateCohortPEM not requiredLongitudinal

Aberrant Resting-State Functional Connectivity in the Salience Network of Adolescent Chronic Fatigue Syndrome.

Wortinger, Laura Anne, Endestad, Tor, Melinder, Annika Maria D et al.·PloS one·2016

This study looked at how the brains of teenagers with ME/CFS show different activity patterns compared to healthy teenagers. Researchers used brain imaging to examine a network called the salience network, which helps the brain notice important signals like pain and fatigue. They found that teenagers with ME/CFS had weaker connections in this network, and the strength of these connections was linked to how severe their fatigue and pain symptoms were.

Chronic Fatigue Syndrome at Age 16 Years.

Collin, Simon M, Norris, Tom, Nuevo, Roberto et al.·Pediatrics·2016

This study found that about 1.9% of 16-year-olds in the UK experience chronic fatigue syndrome (CFS)—a condition causing severe, long-lasting tiredness that lasts at least 6 months and cannot be explained by other illnesses. Girls were nearly twice as likely as boys to have CFS at this age, and young people experiencing more family stress or difficulties were at higher risk. Children with CFS missed significantly more school than their peers.

High prevalence of asymptomatic carriers of Tropheryma whipplei in different populations from the North of Spain.

García-Álvarez, Lara, Pérez-Matute, Patricia, Blanco, José Ramón et al.·Enfermedades infecciosas y microbiologia clinica·2016

Researchers tested stool samples from healthy people, HIV patients, and people with ME/CFS from Spain to see how common a bacterium called Tropheryma whipplei was in each group. They found this bacterium in about 25% of all samples, but it was more common in HIV patients (34%) than in healthy people without other conditions (20%), and was not found in any of the ME/CFS patients tested.

E2 ModerateCohortPEM unclearCase-Control

Reductions in circulating levels of IL-16, IL-7 and VEGF-A in myalgic encephalomyelitis/chronic fatigue syndrome.

Landi, Abdolamir, Broadhurst, David, Vernon, Suzanne D et al.·Cytokine·2016

Researchers measured 34 different immune system proteins in blood samples from 100 ME/CFS patients and 79 healthy controls. They found that three specific immune proteins—IL-16, IL-7, and VEGF-A—were significantly lower in ME/CFS patients. This pattern was different from what is seen in other chronic diseases with similar fatigue symptoms, suggesting it may be unique to ME/CFS.

BiomarkersImmune System

Natural killer cells and single nucleotide polymorphisms of specific ion channels and receptor genes in myalgic encephalomyelitis/chronic fatigue syndrome.

Marshall-Gradisnik, Sonya, Huth, Teilah, Chacko, Anu et al.·The application of clinical genetics·2016

This study looked at immune cells called natural killer cells in ME/CFS patients and compared them to healthy controls. Researchers found that ME/CFS patients had weaker natural killer cell function and carried genetic variations in genes related to calcium regulation and nerve signal transmission. These genetic differences were not found in the healthy control group, suggesting they may play a role in ME/CFS.

Regulatory T, natural killer T and γδ T cells in multiple sclerosis and chronic fatigue syndrome/myalgic encephalomyelitis: a comparison.

Ramos, Sandra, Brenu, Ekua, Broadley, Simon et al.·Asian Pacific journal of allergy and immunology·2016

This study compared immune system cells in people with ME/CFS, people with multiple sclerosis (MS), and healthy people. Researchers found that ME/CFS patients had higher levels of certain regulatory immune cells called Tregs, while MS patients had lower levels of gamma delta T cells. The findings suggest that ME/CFS and MS affect the immune system in different ways, rather than through the same mechanisms.

E2 ModerateCohortPEM unclearCase-Control

Cytokine network analysis of cerebrospinal fluid in myalgic encephalomyelitis/chronic fatigue syndrome.

Hornig, M, Gottschalk, G, Peterson, D L et al.·Molecular psychiatry·2016

Researchers examined fluid from around the spine (cerebrospinal fluid) in ME/CFS patients and compared it to healthy people and those with multiple sclerosis. They found that ME/CFS patients had unusual patterns of immune proteins called cytokines in this fluid, suggesting their immune system in the brain and spinal cord is activated differently. The most notable finding was higher levels of a protein called eotaxin, which typically helps recruit immune cells involved in allergic responses.

A Preliminary Comparative Assessment of the Role of CD8+ T Cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis and Multiple Sclerosis.

Brenu, Ekua W, Broadley, Simon, Nguyen, Thao et al.·Journal of immunology research·2016

This study looked at specific immune cells called CD8+ T cells in people with ME/CFS and compared them to people with multiple sclerosis and healthy controls. Researchers found that ME/CFS patients had lower levels of certain proteins on their CD8+ T cells that help these immune cells function properly. These findings suggest that ME/CFS may involve problems with how immune cells are working, similar to but different from what happens in multiple sclerosis.

E2 ModerateMechanismPEM unclearMechanistic

Abnormal Resting-State Functional Connectivity in Patients with Chronic Fatigue Syndrome: Results of Seed and Data-Driven Analyses.

Gay, Charles W, Robinson, Michael E, Lai, Song et al.·Brain connectivity·2016

This study used brain imaging (MRI) to examine how different regions of the brain communicate with each other in people with ME/CFS compared to healthy people. Researchers found that people with ME/CFS have weaker communication between certain brain regions, particularly in areas involved in attention and movement. These abnormal communication patterns were directly linked to how severe patients' fatigue symptoms were.

ERK1/2, MEK1/2 and p38 downstream signalling molecules impaired in CD56 dim CD16+ and CD56 bright CD16 dim/- natural killer cells in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis patients.

Huth, Teilah Kathryn, Staines, Donald, Marshall-Gradisnik, Sonya·Journal of translational medicine·2016

This study looked at natural killer (NK) cells, which are immune cells that help fight infections and abnormal cells. Researchers found that NK cells in ME/CFS patients have problems with their internal signaling systems—the chemical pathways that tell these cells to attack threats. Specifically, certain types of NK cells showed abnormal activity in proteins called ERK, MEK, and p38 when compared to healthy people. These problems in cell signaling might explain why people with ME/CFS have weaker immune responses.

E2 ModerateBehavioralPEM not requiredObservational

Chronic fatigue syndrome: comparing outcomes in White British and Black and minority ethnic patients after cognitive-behavioural therapy.

Ingman, Tom, Ali, Sheila, Bhui, Kamaldeep et al.·The British journal of psychiatry : the journal of mental science·2016

This study looked at whether cognitive-behavioural therapy (CBT)—a talking therapy that helps change thought patterns and behaviours—works equally well for ME/CFS patients from Black and minority ethnic (BME) backgrounds compared to White British patients. Both groups showed significant improvements in fatigue, physical functioning, and ability to work or socialise after CBT treatment. Importantly, BME patients improved despite starting with more negative beliefs about their condition and more avoidance behaviours.

Interventions

BiomarkersEnergy Metabolism

Index markers of chronic fatigue syndrome with dysfunction of TCA and urea cycles.

Yamano, Emi, Sugimoto, Masahiro, Hirayama, Akiyoshi et al.·Scientific reports·2016

Researchers analyzed blood samples from ME/CFS patients and healthy people to look for chemical markers that could help diagnose the disease. They found that certain metabolites—molecules involved in energy production and waste removal—were abnormal in ME/CFS patients. Two specific chemical ratios in the blood showed promise as potential diagnostic tools, correctly identifying CFS patients about 75-80% of the time.

E2 ModerateCohortPEM unclear

Factors facilitating patient satisfaction among women with medically unexplained long-term fatigue: A relational perspective.

Lian, Olaug S, Hansen, Anne Helen·Health (London, England : 1997)·2016

This study surveyed 431 women with ME/CFS about their experiences with doctors in Norway. The researchers found that patients were most satisfied when their doctor understood their illness, saw them regularly, and referred them to specialists. The most important factor was feeling like an equal partner with their doctor rather than just being told what to do.

Diagnostics

Association of mitochondrial DNA variants with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptoms.

Hanson, Maureen R, Gu, Zhenglong, Keinan, Alon et al.·Journal of translational medicine·2016

This study looked at whether variations in mitochondrial DNA (the genetic material in the energy-producing parts of our cells) are linked to ME/CFS. Researchers compared genetic samples from ME/CFS patients and healthy people. While they didn't find that specific DNA variants caused the disease itself, they did discover that certain genetic variations were associated with specific symptoms and how severe those symptoms were.

Energy Metabolism

Support for the Microgenderome: Associations in a Human Clinical Population.

Wallis, Amy, Butt, Henry, Ball, Michelle et al.·Scientific reports·2016

This study looked at gut bacteria in 274 ME/CFS patients and found that certain bacteria may affect symptoms differently in men and women, even when they have similar amounts of these bacteria. Specific bacteria called Firmicutes (including types like Clostridium and Lactobacillus) appeared connected to neurological, immune, and mood symptoms, but the way they affected symptoms depended on the patient's sex. This suggests that sex differences matter when understanding how gut bacteria influence ME/CFS.