ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2741–2760 of 6,209 studies

E2 ModerateCohortPEM not requiredObservational

Cardiac function fluctuates during exacerbation and remission in young adults with chronic fatigue syndrome and "small heart".

Miwa, Kunihisa, Fujita, Masatoshi·Journal of cardiology·2009

This study looked at the hearts of 42 young adults with ME/CFS and found that 62% had unusually small hearts on chest X-rays. Using heart ultrasound scans, researchers discovered these patients had smaller heart chambers and weaker heart function compared to healthy controls. Importantly, when patients improved, their heart size and function got better, suggesting the heart changes are connected to symptom severity rather than permanent damage.

E2 ModerateCohortPEM not requiredCross-Sectional

Lower plasma Coenzyme Q10 in depression: a marker for treatment resistance and chronic fatigue in depression and a risk factor to cardiovascular disorder in that illness.

Maes, Michael, Mihaylova, Ivanka, Kubera, Marta et al.·Neuro endocrinology letters·2009

This study found that people with depression have lower levels of Coenzyme Q10 (CoQ10), a natural substance in the body that helps protect cells from damage, compared to healthy people. The researchers discovered that people with depression who don't respond well to treatment and those with chronic fatigue had even lower CoQ10 levels. This suggests that CoQ10 might play a role in why some people with depression feel persistently tired and why depression can increase heart disease risk.

E2 ModerateCohortPEM not requiredCross-Sectional

Are chronic fatigue and chronic fatigue syndrome valid clinical entities across countries and health-care settings?

Hickie, Ian, Davenport, Tracey, Vernon, Suzanne D et al.·The Australian and New Zealand journal of psychiatry·2009

This large international study analyzed data from nearly 38,000 people across 21 countries to determine whether chronic fatigue and ME/CFS are real, recognizable conditions. Researchers found that people with these conditions share a consistent pattern of five main symptom types—muscle pain and fatigue, thinking difficulties, inflammation-related symptoms, sleep problems, and mood changes—regardless of where they live or which type of doctor they see. This consistency across different countries and healthcare settings provides strong evidence that chronic fatigue and ME/CFS are genuine medical conditions, not just psychiatric problems.

Diagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

Comparative epidemiology of chronic fatigue syndrome in Brazilian and British primary care: prevalence and recognition.

Cho, Hyong Jin, Menezes, Paulo Rossi, Hotopf, Matthew et al.·The British journal of psychiatry : the journal of mental science·2009

This study looked at how often ME/CFS occurs in two very different cities—London and São Paulo, Brazil—and whether doctors recognize it as a real condition. Researchers surveyed over 6,000 primary care patients and found that ME/CFS affected roughly the same number of people in both places (about 2%). However, while British doctors had diagnosed some cases, Brazilian doctors had not diagnosed any, suggesting that cultural and healthcare system differences affect how the disease is recognized rather than how common it actually is.

Diagnostics

E2 ModerateBehavioralPEM unclearObservational

The impact of energy modulation on physical functioning and fatigue severity among patients with ME/CFS.

Jason, Leonard, Benton, Mary, Torres-Harding, Susan et al.·Patient education and counseling·2009

This study looked at whether ME/CFS patients could improve by carefully managing their daily energy use to match their available energy. Researchers tracked patients who tried to stay within their "energy envelope"—basically not spending more energy than they have. Patients who were able to do this successfully reported feeling less tired and being more physically able to do daily activities.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Sleep apnea and psychological functioning in chronic fatigue syndrome.

Libman, Eva, Creti, Laura, Baltzan, Marcel et al.·Journal of health psychology·2009

This study looked at whether sleep apnea (a condition where breathing stops and starts during sleep) is common in people with ME/CFS and how it affects mood and psychological well-being. The researchers found that 68% of ME/CFS patients had sleep apnea, but those who did were not significantly more ill than those without it. Both the ME/CFS and sleep apnea groups showed more psychological difficulties than healthy controls, but the researchers suggest these emotional struggles are likely a natural response to living with a chronic illness rather than a separate psychiatric condition.

SleepDiagnostics

E2 ModerateCohortPEM not requiredCase-Control

Physiological cost of walking in those with chronic fatigue syndrome (CFS): a case-control study.

Paul, Lorna, Rafferty, Danny, Marshal, Rebecca·Disability and rehabilitation·2009

This study compared how much energy people with ME/CFS use when walking compared to healthy people. Researchers found that people with ME/CFS walk more slowly and use more energy per unit of distance covered, meaning their bodies have to work harder to move the same distance as healthy people.

Energy MetabolismPost-Exertional Malaise

E2 ModerateCohortPEM not requiredLongitudinal

Chronic fatigue syndrome after infectious mononucleosis in adolescents.

Katz, Ben Z, Shiraishi, Yukiko, Mears, Cynthia J et al.·Pediatrics·2009

This study followed 301 teenagers with infectious mononucleosis (mono) to see how many developed ME/CFS afterward. Researchers checked in at 6, 12, and 24 months and found that fewer teenagers had ME/CFS as time went on: 13% at 6 months, 7% at 12 months, and 4% at 24 months. All 13 teenagers still diagnosed with ME/CFS at 24 months were female, and they had reported more severe fatigue earlier in their illness.

E2 ModerateCohortPEM unclearCross-Sectional

Further validation of the Multidimensional Fatigue Inventory in a US adult population sample.

Lin, Jin-Mann S, Brimmer, Dana J, Maloney, Elizabeth M et al.·Population health metrics·2009

This study tested whether a 20-question fatigue measurement tool (the MFI-20) works well for people with ME/CFS and other chronic illnesses. Researchers gave the questionnaire to 783 people in Georgia—some with ME/CFS-like illness, some with chronic unwellness, and some who were healthy—and found that the tool reliably distinguished between these groups and accurately measured different types of fatigue.

E2 ModerateCohortPEM not requiredCross-Sectional

Diurnal pattern of cortisol output in postnatal depression.

Taylor, Alyx, Glover, Vivette, Marks, Maureen et al.·Psychoneuroendocrinology·2009

This study looked at how stress hormone (cortisol) levels change throughout the day in women with depression after having a baby, compared to women without postpartum depression and non-pregnant women. The researchers found that depressed women had unusually high cortisol levels when they woke up and didn't show the normal increase in cortisol that typically happens 30 minutes after waking, which is similar to patterns seen in chronic fatigue syndrome.

Endocrine Disruption

E2 ModerateCohortPEM not requiredCase-Control

Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study.

Burton, Christopher, Knoop, Hans, Popovic, Nikola et al.·BioPsychoSocial medicine·2009

This study measured how people with ME/CFS move and rest over a 12-day period compared to healthy people. Researchers found that people with ME/CFS have activity patterns that are more repetitive and predictable—like a broken record—whereas healthy people's activity patterns are more varied and flexible. This difference held true even when accounting for the fact that ME/CFS patients were less active overall.

E2 ModerateCohortPEM not requiredCross-Sectional

Anticardiolipin antibodies in the sera of patients with diagnosed chronic fatigue syndrome.

Hokama, Yoshitsugi, Campora, Cara Empey, Hara, Cynthia et al.·Journal of clinical laboratory analysis·2009

Researchers tested blood samples from ME/CFS patients and found abnormal antibodies called anticardiolipin antibodies (ACAs) in 95% of the samples. These antibodies mistakenly attack cardiolipin, a substance found in cell membranes. The study suggests that something in the immune system may be going wrong in ME/CFS, possibly affecting how cells produce energy.

Immune System

E2 ModerateCohortPEM not requiredCase-Control

Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study.

Pietrangelo, T, Toniolo, L, Paoli, A et al.·International journal of immunopathology and pharmacology·2009

This study looked at muscle tissue from ME/CFS patients and compared it to healthy controls. Researchers found that ME/CFS patients had a shift in their muscle fiber types—more of the fast-twitch fibers (which tire easily) and fewer slow-twitch fibers (which are better for endurance). However, the individual muscle fibers themselves worked normally; the problem was the wrong mix of fiber types, which could explain why ME/CFS patients get tired so quickly.

E2 ModerateCohortPEM not requiredCross-Sectional

Autoantibodies, polymorphisms in the serotonin pathway, and human leukocyte antigen class II alleles in chronic fatigue syndrome: are they associated with age at onset and specific symptoms?

Ortega-Hernandez, Oscar-Danilo, Cuccia, Mariaclara, Bozzini, Sara et al.·Annals of the New York Academy of Sciences·2009

This study looked at whether certain genetic traits and immune markers in the blood are linked to when ME/CFS develops and what symptoms people experience. Researchers tested 81 ME/CFS patients for specific genes related to serotonin (a brain chemical), immune system genes, and antibodies. They found that different genetic patterns were associated with developing ME/CFS at different ages and with certain symptoms like joint pain and fever, but not muscle pain.

Immune System

E2 ModerateCohortPEM unclearCross-Sectional

Implications of gender in chronic Lyme disease.

Wormser, Gary P, Shapiro, Eugene D·Journal of women's health (2002)·2009

This study compared three groups of patients: those with confirmed Lyme disease, those with lingering symptoms after Lyme disease treatment (post-Lyme disease syndrome), and those diagnosed with 'chronic Lyme disease' (a less clearly defined condition). The researchers found that women made up a much larger percentage of the chronic Lyme disease group compared to the other two groups. This suggests that some patients labeled with chronic Lyme disease may actually have other conditions like fibromyalgia or chronic fatigue syndrome that also affect more women.

Diagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

An investigation into the cognitive deficits associated with chronic fatigue syndrome.

Thomas, Marie, Smith, Andrew·The open neurology journal·2009

This study tested whether people with ME/CFS have real problems with thinking and memory, not just imagine they do. The researchers gave a large group of properly diagnosed ME/CFS patients a thorough set of cognitive tests and found clear evidence of cognitive difficulties. Importantly, these problems were not caused by depression or anxiety, suggesting they are a direct part of the illness.

Cognitive Impairment

E2 ModerateBehavioralPEM not requiredCross-Sectional

"Functional" or "psychosomatic" symptoms, e.g. a flu-like malaise, aches and pain and fatigue, are major features of major and in particular of melancholic depression.

Maes, Michael·Neuro endocrinology letters·2009

This study looked at whether depression and ME/CFS share similar physical symptoms like fatigue, muscle pain, and feeling like you have an infection. Researchers found that people with severe depression often experience these "body-centered" symptoms as a major part of their illness. The findings suggest that doctors should pay more attention to these physical symptoms when diagnosing and treating depression.

Pain and SensitizationCognitive Impairment

E2 ModerateCohortPEM not requiredCross-Sectional

Replication of an empirical approach to delineate the heterogeneity of chronic unexplained fatigue.

Aslakson, Eric, Vollmer-Conna, Uté, Reeves, William C et al.·Population health metrics·2009

This study looked at nearly 400 women from different parts of Georgia to understand why chronic fatigue affects people so differently. Instead of treating all chronic fatigue as one disease, researchers found that people fall into five distinct groups with different symptom patterns—some with sleep and mood problems, some with weight and metabolic issues, and some without significant fatigue at all. The findings suggest that chronic fatigue is not one-size-fits-all, and doctors may need personalized approaches for different patient groups.

Sleep

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome and DSM-IV personality disorders.

Courjaret, Joachime, Schotte, Christiaan K W, Wijnants, Herlindis et al.·Journal of psychosomatic research·2009

This study looked at whether ME/CFS patients have more personality disorders than people without ME/CFS. Researchers tested 50 women with ME/CFS and compared them to 50 healthy women and 50 women with psychiatric conditions. They found that women with ME/CFS had similar personality traits and rates of personality disorders as healthy women, suggesting that personality problems are not a major cause of ME/CFS.

E2 ModerateCohortPEM not requiredCross-Sectional

High slow-wave sleep and low-light sleep: chronic fatigue syndrome is not likely to be a primary sleep disorder.

Neu, Daniel, Cappeliez, Bernard, Hoffmann, Guy et al.·Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society·2009

This study compared sleep patterns between people with ME/CFS and people with a primary sleep disorder (sleep apnea) to see if ME/CFS might actually be a sleep problem in disguise. Researchers found that ME/CFS patients have distinctly different sleep patterns—more deep sleep and fewer light sleep stages—compared to people with actual sleep disorders. This suggests ME/CFS is not primarily a sleep disorder, even though both conditions cause people to feel unrefreshed.

Sleep

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Cardiac function fluctuates during exacerbation and remission in young adults with chronic fatigue syndrome and "small heart".

Lower plasma Coenzyme Q10 in depression: a marker for treatment resistance and chronic fatigue in depression and a risk factor to cardiovascular disorder in that illness.

Are chronic fatigue and chronic fatigue syndrome valid clinical entities across countries and health-care settings?

Comparative epidemiology of chronic fatigue syndrome in Brazilian and British primary care: prevalence and recognition.

The impact of energy modulation on physical functioning and fatigue severity among patients with ME/CFS.

Sleep apnea and psychological functioning in chronic fatigue syndrome.

Physiological cost of walking in those with chronic fatigue syndrome (CFS): a case-control study.

Chronic fatigue syndrome after infectious mononucleosis in adolescents.

Further validation of the Multidimensional Fatigue Inventory in a US adult population sample.

Diurnal pattern of cortisol output in postnatal depression.

Reduced complexity of activity patterns in patients with chronic fatigue syndrome: a case control study.

Anticardiolipin antibodies in the sera of patients with diagnosed chronic fatigue syndrome.

Functional characterization of muscle fibres from patients with chronic fatigue syndrome: case-control study.

Autoantibodies, polymorphisms in the serotonin pathway, and human leukocyte antigen class II alleles in chronic fatigue syndrome: are they associated with age at onset and specific symptoms?

Implications of gender in chronic Lyme disease.

An investigation into the cognitive deficits associated with chronic fatigue syndrome.

"Functional" or "psychosomatic" symptoms, e.g. a flu-like malaise, aches and pain and fatigue, are major features of major and in particular of melancholic depression.

Replication of an empirical approach to delineate the heterogeneity of chronic unexplained fatigue.

Chronic fatigue syndrome and DSM-IV personality disorders.

High slow-wave sleep and low-light sleep: chronic fatigue syndrome is not likely to be a primary sleep disorder.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research