Evidence browser

E2 ModerateCohortPEM requiredCross-Sectional

Chronic fatigue syndrome patients have alterations in their oral microbiome composition and function.

Wang, Taiwu, Yu, Lei, Xu, Cong et al.·PloS one·2018

Researchers studied the bacteria living in the mouths of ME/CFS patients and compared them to healthy people. They found that ME/CFS patients have a different balance of oral bacteria, with some types being more common and others less common. These bacterial differences appear to affect how the body processes energy and amino acids, which could be relevant to understanding ME/CFS.

Energy Metabolism

Deconstructing post-exertional malaise in myalgic encephalomyelitis/ chronic fatigue syndrome: A patient-centered, cross-sectional survey.

Chu, Lily, Valencia, Ian J, Garvert, Donn W et al.·PloS one·2018

This study asked 150 ME/CFS patients to describe what happens when they experience post-exertional malaise (PEM)—the characteristic crash that follows physical activity, mental effort, or emotional stress. Researchers found that 90% of patients experienced PEM from all three types of triggers, with fatigue being the most common symptom, but also cognitive problems, sleep issues, headaches, and muscle pain. Most patients' PEM lasted at least 24 hours, though the timing and severity varied from person to person.

Post-Exertional Malaise

Intracranial compliance is associated with symptoms of orthostatic intolerance in chronic fatigue syndrome.

Finkelmeyer, Andreas, He, Jiabao, Maclachlan, Laura et al.·PloS one·2018

Many people with ME/CFS experience dizziness or lightheadedness when standing up—a condition called orthostatic intolerance. This study used brain imaging to measure how well the brain's blood vessels and fluid systems adjust to position changes. Researchers found that ME/CFS patients with worse symptoms had less flexible brain spaces and higher blood flow at rest, suggesting their brains may struggle to maintain proper blood flow when standing.

Autonomic Nervous System

E2 ModerateCohortPEM unclearCase-Control

The X-Y factor: Females and males with urological chronic pelvic pain syndrome present distinct clinical phenotypes.

Hosier, Gregory W, Doiron, R Christopher, Tolls, Victoria et al.·Canadian Urological Association journal = Journal de l'Association des urologues du Canada·2018

This study compared how chronic pelvic pain affects men and women differently. Researchers found that women with pelvic pain had more bladder symptoms, nerve-related symptoms, and were more likely to have other conditions like chronic fatigue syndrome, fibromyalgia, and depression. Men and women with the same diagnosis actually experience quite different patterns of pain and related health problems.

Identification of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome-associated DNA methylation patterns.

Trivedi, Malav S, Oltra, Elisa, Sarria, Leonor et al.·PloS one·2018

Researchers studied chemical tags on DNA (called methylation) in people with ME/CFS compared to healthy people. While the overall amount of these tags was similar between groups, they found specific locations on thousands of genes where the tags differed. Many of these differences were in genes involved in immune system function, which aligns with what doctors already know about ME/CFS affecting immunity.

BiomarkersImmune System

Comparison of Fatigue Severity and Quality of Life between Unexplained Fatigue Patients and Explained Fatigue Patients.

Yoo, Eun Hae, Choi, Eun Sil, Cho, Soo Hyun et al.·Korean journal of family medicine·2018

This study compared fatigue and quality of life in 200 Korean adults with fatigue. Researchers divided participants into two groups: those whose fatigue had a clear medical explanation (like anemia or thyroid disease) and those whose fatigue remained unexplained after testing. People with unexplained fatigue reported significantly lower quality of life, especially in physical functioning, compared to those with explained fatigue.

Operationalizing Substantial Reduction in Functioning Among Young Adults with Chronic Fatigue Syndrome.

Gleason, Kristen D, Stoothoff, Jamie, McClellan, Damani et al.·International journal of behavioral medicine·2018

This study looked for the best way to measure the 'substantial reduction in functioning' that is required for ME/CFS diagnosis. Researchers used a standard health survey (SF-36) with young adults (ages 18-29) who had ME/CFS and compared them to people without the condition. They found that specific cutoff scores on four areas of the survey—physical functioning, general health, role physical (ability to work), and social functioning—could accurately identify who has ME/CFS.

E2 ModerateCohortPEM not requiredCase-Control

Glucocorticoid receptor DNA methylation and childhood trauma in chronic fatigue syndrome patients.

Vangeel, Elise Beau, Kempke, Stefan, Bakusic, Jelena et al.·Journal of psychosomatic research·2018

This study looked at chemical changes (called methylation) on genes that control how the body handles stress in people with ME/CFS compared to healthy controls. The researchers found small but consistent differences in a stress-response gene, particularly in patients who had experienced childhood trauma. While the differences were tiny (about 1-2%), they suggest that ME/CFS may involve changes in how the body's stress system works.

Endocrine Disruption

E2 ModerateCohortPEM unclearObservational

Why do some ME/CFS patients benefit from treatment with sodium dichloroacetate, but others do not?

Comhaire, Frank·Medical hypotheses·2018

This study looked at why some ME/CFS patients improve when taking sodium dichloroacetate (DCA), a drug that helps mitochondria—the energy centers of cells—work better, while others don't benefit at all. By examining 35 ME/CFS patients, researchers found 6 specific patient characteristics that could predict who would respond well to DCA treatment. These findings suggest doctors might be able to identify which patients are most likely to benefit from this treatment before they start taking it.

Interventions

E2 ModerateCohortPEM requiredCross-Sectional

Visual Aspects of Reading Performance in Myalgic Encephalomyelitis (ME).

Wilson, Rachel L, Paterson, Kevin B, McGowan, Victoria et al.·Frontiers in psychology·2018

This study tested reading and vision abilities in 27 people with ME/CFS and compared them to healthy controls. Researchers found that people with ME/CFS read more slowly and had greater difficulty reading when text was crowded together, even though their basic vision was similar to controls. These findings suggest that vision-related reading problems in ME/CFS are real and measurable, not just imagined.

Cognitive Impairment

Systemic exertion intolerance disease diagnostic criteria applied on an adolescent chronic fatigue syndrome cohort: evaluation of subgroup differences and prognostic utility.

Asprusten, Tarjei Tørre, Sulheim, Dag, Fagermoen, Even et al.·BMJ paediatrics open·2018

This study looked at whether a diagnostic checklist called SEID (Systemic Exertion Intolerance Disease) could reliably identify and predict outcomes in teenagers with ME/CFS. The researchers compared 120 adolescents who did or didn't meet the SEID criteria and found that the criteria didn't actually help predict who would improve over time. Interestingly, teens who met the SEID criteria were more likely to show symptoms of depression, which raises questions about whether the criteria are truly measuring ME/CFS itself.

E2 ModerateBehavioralPEM not requiredLongitudinal

Reciprocal associations between daily need-based experiences, energy, and sleep in chronic fatigue syndrome.

Campbell, Rachel, Vansteenkiste, Maarten, Delesie, Liesbeth et al.·Health psychology : official journal of the Division of Health Psychology, American Psychological Association·2018

This study tracked 120 ME/CFS patients for 14 days to understand how their daily psychological needs, energy levels, and sleep quality relate to each other. Researchers found that on days when patients felt their needs were met (feeling in control, capable, and connected to others), they had more energy and better sleep. On days when patients felt frustrated in meeting these needs, they experienced more fatigue and worse sleep quality.

Sleep

E2 ModerateBehavioralPEM not requiredCross-Sectional

A reexamination of the cognitive behavioral model of chronic fatigue syndrome.

Sunnquist, Madison, Jason, Leonard A·Journal of clinical psychology·2018

This study tested whether the idea that ME/CFS is caused or worsened mainly by unhelpful thoughts and not being active enough actually explains what happens to patients with ME/CFS. Researchers looked at 990 people with ME/CFS and found this explanation didn't fit well, especially for people who met stricter diagnostic criteria. The findings suggest that ME/CFS may work differently than this model assumes.

Chronic fatigue syndrome in Chinese middle-school students.

Shi, Jieyao, Shen, Jie, Xie, Jian et al.·Medicine·2018

Researchers in China surveyed over 18,000 middle school students to see how many had chronic fatigue syndrome (CFS). They found that about 1 in 100 students met the criteria for CFS, with older students and boys more commonly affected. Beyond typical tiredness, these students also reported school anxiety, sadness, and irritability, suggesting CFS in teenagers may involve emotional symptoms alongside physical exhaustion.

E2 ModerateDiagnosticPEM unclearMethods-Paper

Blood Volume Status in ME/CFS Correlates With the Presence or Absence of Orthostatic Symptoms: Preliminary Results.

van Campen, C Linda M C, Rowe, Peter C, Visser, Frans C·Frontiers in pediatrics·2018

This study measured the amount of blood circulating in the bodies of 20 adults with ME/CFS and found that those with symptoms of dizziness or lightheadedness when standing up had significantly less blood volume than those without these symptoms. On average, all ME/CFS patients had about 11 milliliters less blood per kilogram of body weight than expected, but the drop was much more pronounced in patients with orthostatic symptoms. This finding suggests that reduced blood volume may be connected to specific symptoms some ME/CFS patients experience.

Autonomic Nervous System

Defining the minimally clinically important difference of the SF-36 physical function subscale for paediatric CFS/ME: triangulation using three different methods.

Brigden, Amberly, Parslow, Roxanne M, Gaunt, Daisy et al.·Health and quality of life outcomes·2018

This study determined the smallest meaningful improvement in physical function that children and teenagers with ME/CFS can experience. Researchers asked young patients and their parents what amount of improvement would feel worthwhile, and they also analyzed clinical data from a specialist service. They found that an improvement of 10 points on a standard physical function scale represents a clinically meaningful change for children with ME/CFS.