ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

81–100 of 210 studies

E2 ModerateCohortPEM unclearCross-Sectional

Urinary and plasma organic acids and amino acids in chronic fatigue syndrome.

Jones, Mark G, Cooper, Elizabeth, Amjad, Saira et al.·Clinica chimica acta; international journal of clinical chemistry·2005

Researchers tested blood and urine samples from ME/CFS patients and compared them to healthy people, those with depression, and those with rheumatoid arthritis. Previous studies claimed certain chemicals in urine were markers for ME/CFS, but this study could not confirm those earlier findings. However, the study did find some signs of inflammation and possible muscle changes that might explain why ME/CFS patients experience fatigue and muscle pain.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Plasma and urinary carnitine and acylcarnitines in chronic fatigue syndrome.

Jones, Mark G, Goodwin, C Stewart, Amjad, Saira et al.·Clinica chimica acta; international journal of clinical chemistry·2005

Researchers tested whether people with ME/CFS have low levels of carnitine, a substance that helps muscles produce energy. They compared blood and urine samples from 31 ME/CFS patients with samples from healthy people and patients with other conditions. The study found no significant differences in carnitine levels between the groups, suggesting that low carnitine is not responsible for the fatigue experienced by ME/CFS patients.

Energy Metabolism

E2 ModerateCohortPEM not requiredCase-Control

The distribution of white blood cell fat oxidation in health and disease.

Pendergast, D R, Fisher, N M, Meksawan, K et al.·Journal of inherited metabolic disease·2004

This study looked at how white blood cells use fat for energy in different groups of people, including those with ME/CFS. Researchers measured fat burning in blood cells from healthy controls, people with ME/CFS, people with other conditions, and athletes. They found that people with ME/CFS had unusually high fat oxidation in their white blood cells, while people with a genetic disorder (CPT II deficiency) had very low fat oxidation.

Energy Metabolism

E2 ModerateCohortPEM not requiredObservational

Enterovirus related metabolic myopathy: a postviral fatigue syndrome.

Lane, R J M, Soteriou, B A, Zhang, H et al.·Journal of neurology, neurosurgery, and psychiatry·2003

Researchers tested muscle samples from ME/CFS patients to see if they contained enterovirus (a type of virus). They found that about 21% of ME/CFS patients had enterovirus in their muscles, while none of the healthy control subjects did. Patients with enterovirus in their muscles were more likely to show abnormal lactate (a byproduct of muscle work) buildup during exercise, suggesting their muscles weren't using energy efficiently.

Energy MetabolismPost-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction.

Robinson, G L, McGregor, N R, Roberts, T K et al.·Perceptual and motor skills·2001

This study looked at 61 people with ME/CFS to see if they also had a visual processing problem called Irlen Syndrome (where certain patterns and lighting cause visual discomfort). Researchers found that people with more severe visual problems had different levels of certain fats and amino acids in their blood and urine compared to those with milder visual symptoms. The authors suggest these differences might show signs of immune system activation, possibly from an infection.

Energy MetabolismImmune System

E2 ModerateCohortPEM not requiredCase-Control

Integrity of the growth hormone/insulin-like growth factor system is maintained in patients with chronic fatigue syndrome.

Cleare, A J, Sookdeo, S S, Jones, J et al.·The Journal of clinical endocrinology and metabolism·2000

This study investigated whether people with ME/CFS have problems with growth hormone (GH), a chemical in the body that affects energy and metabolism. Researchers compared 37 ME/CFS patients to 37 healthy controls by measuring various growth hormone-related substances in their blood and urine, and tested how their bodies responded to specific hormone challenges. They found no significant differences between the two groups, suggesting that ME/CFS is not caused by growth hormone deficiency.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Vitamin B status in patients with chronic fatigue syndrome.

Heap, L C, Peters, T J, Wessely, S·Journal of the Royal Society of Medicine·1999

This study tested whether people with ME/CFS have lower levels of three B vitamins (B6, B2, and B1) compared to healthy people. Researchers measured how well these vitamins work in red blood cells from 12 ME/CFS patients and 18 healthy controls. They found that all three B vitamins appeared to be functioning less effectively in ME/CFS patients, suggesting a possible vitamin deficiency that might contribute to symptoms.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Low levels of serum acylcarnitine in chronic fatigue syndrome and chronic hepatitis type C, but not seen in other diseases.

Kuratsune, H, Yamaguti, K, Lindh, G et al.·International journal of molecular medicine·1998

Researchers measured a substance called acylcarnitine in the blood of people with ME/CFS and compared it to healthy people and those with other diseases. They found that people with ME/CFS had significantly lower levels of this substance, and this same pattern appeared in both Japanese and Swedish patients. Importantly, this low level was only seen in ME/CFS and one other condition (chronic hepatitis C), not in other common diseases like diabetes or high blood pressure.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Phosphate diabetes in patients with chronic fatigue syndrome.

De Lorenzo, F, Hargreaves, J, Kakkar, V V·Postgraduate medical journal·1998

This study explored whether some ME/CFS patients might actually have a rare kidney condition called phosphate diabetes, which prevents the kidneys from properly reabsorbing phosphate. Phosphate is important for muscle and nerve function, and low levels can cause fatigue, muscle pain, and depression—symptoms that overlap with ME/CFS. The researchers tested 87 ME/CFS patients and found that 9 of them also had phosphate diabetes.

Energy Metabolism

E2 ModerateCohortPEM unclearCase-Control

A common genetic variant affecting folate metabolism is not over-represented in chronic fatigue syndrome.

Harmon, D L, McMaster, D, McCluskey, D R et al.·Annals of clinical biochemistry·1997

This study looked at whether a specific genetic variant related to how the body processes folate (a B vitamin) is more common in people with ME/CFS compared to healthy controls. The researchers found that this particular genetic variation was not significantly more frequent in ME/CFS patients, suggesting this specific genetic factor is unlikely to be a major cause of the condition.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Serum carnitine and disabling fatigue in multiple sclerosis.

Fukazawa, T, Sasaki, H, Kikuchi, S et al.·Psychiatry and clinical neurosciences·1996

This study tested whether a substance called carnitine, which helps muscles use fat for energy, might be low in people with multiple sclerosis (MS) and could explain their severe fatigue. Researchers compared carnitine levels in 25 MS patients and healthy people of similar age and sex, but found no differences between groups or between MS patients with and without severe fatigue.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Preliminary determination of a molecular basis of chronic fatigue syndrome.

McGregor, N R, Dunstan, R H, Zerbes, M et al.·Biochemical and molecular medicine·1996

Researchers tested the urine of 20 ME/CFS patients and 45 healthy controls to look for chemical differences. They found that ME/CFS patients had different levels of several substances in their urine, particularly one called CFSUM1 and beta-alanine, which were higher in patients with more severe symptoms. These findings suggest ME/CFS may have measurable biological markers that could help identify the condition.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Serum levels of carnitine in chronic fatigue syndrome: clinical correlates.

Plioplys, A V, Plioplys, S·Neuropsychobiology·1995

This study looked at carnitine, a substance that helps cells produce energy. Researchers found that people with ME/CFS have lower levels of carnitine in their blood compared to what would be expected. They also discovered that patients with higher carnitine levels reported better ability to function in daily life, suggesting a link between this energy-related chemical and symptom severity.

Energy Metabolism

E3 PreliminaryMechanismPEM not requiredMechanistic

[Effect of warming needle moxibustion on mitochondrial autophagy in rats with chronic fatigue syndrome based on AMPK/ULK1 signaling pathway].

Yuan, Yi-Na, Liu, Di, Liu, Jun-Wei et al.·Zhen ci yan jiu = Acupuncture research·2026

This study tested whether a traditional acupuncture technique called warming needle moxibustion could help rats with chronic fatigue syndrome by improving how their muscle cells produce energy. Researchers found that the treatment improved the rats' activity levels and physical strength, and appeared to work by activating cellular pathways that help damaged mitochondria (the cell's energy factories) clean themselves up and function better.

Energy Metabolism

E3 PreliminaryReviewPEM unclearReview-Narrative

A research perspective on sphingolipid metabolism and myalgic encephalomyelitis/chronic fatigue syndrome.

Xiao, Junhua·Neural regeneration research·2026

This study examines how the body breaks down and uses a type of fat called sphingolipids, which are important for nerve cell function and communication. The researchers reviewed existing knowledge about sphingolipid metabolism to understand whether problems in this process might contribute to ME/CFS symptoms like fatigue and pain. This perspective piece suggests that disruptions in how the body handles these fats could potentially play a role in the disease, though more research is needed to confirm this.

Energy Metabolism

E3 PreliminaryMechanismPEM unclearCross-Sectional

Exploring a genetic basis for the metabolic perturbations in ME/CFS using UK biobank.

Huang, Katherine, Muneeb, Muhammad, Thomas, Natalie et al.·iScience·2026

Researchers examined blood samples from nearly 900 ME/CFS patients to understand how genes influence metabolism in this condition. They found that people with ME/CFS have different genetic patterns affecting fat and lipid metabolism compared to healthy people, particularly involving genes related to immune function. These genetic differences may help explain why ME/CFS affects different people in different ways.

Energy MetabolismImmune System

E3 PreliminaryCommentaryPEM requiredEditorial

Expert perspectives on Myalgic encephalomyelitis/chronic fatigue syndrome - Insights from the 3rd International Conference of the Charité Fatigue Center.

Fehrer, Annick, Windzio, Lara, Schoening, Simon et al.·Autoimmunity reviews·2026

Nearly 4,000 ME/CFS researchers and experts gathered at an international conference in May 2025 to share the latest discoveries about this serious illness. They discussed how ME/CFS develops, better ways to diagnose it, and new treatments being tested. The conference highlighted that while COVID-19 has brought more attention and funding to ME/CFS research, the disease is still not well understood and needs much more study.

Energy MetabolismImmune SystemPost-Exertional Malaise

E3 PreliminaryMechanismPEM unclearMechanistic

Indistinguishable mitochondrial phenotypes after exposure of healthy myoblasts to myalgic encephalomyelitis/chronic fatigue syndrome or control serum.

Ryback, Audrey A, Hillier, Charles B, Loureiro, Camila M et al.·PloS one·2026

Researchers wanted to test whether something in the blood of people with ME/CFS could damage the energy-producing parts of cells (mitochondria) when added to healthy cells in the lab. They tested blood from 67 people with ME/CFS and 53 healthy people on cultured muscle cells and measured how well the cells could use oxygen. Unlike a previous smaller study, they found no difference between the ME/CFS blood and healthy blood samples.

BiomarkersEnergy Metabolism

E3 PreliminaryCohortPEM requiredCase-Control

Significant aggravation of pre-existing myalgic encephalomyelitis/chronic fatigue syndrome following proton beam therapy for sphenoid wing meningioma: case report.

Fischer, Christian, Seidlitz, Annekatrin, Krause, Mechthild·Strahlentherapie und Onkologie : Organ der Deutschen Rontgengesellschaft ... [et al]·2026

This is a single case report of a 46-year-old woman with ME/CFS whose condition severely worsened after receiving proton beam radiation therapy for a brain tumor. Over months following treatment, she went from being ambulatory to completely bedridden, with worsening fatigue, pain, dizziness, and cognitive problems. The report suggests that radiation may have triggered this deterioration, but it remains unclear whether this outcome would occur in other ME/CFS patients undergoing similar treatment.

Pain and SensitizationSevere MEEnergy MetabolismCognitive Impairment

E3 PreliminaryReviewPEM not requiredReview-Narrative

Pathophysiological mechanisms of fatigue and multidisciplinary management strategies (Review).

Zhou, Hong, Yu, Wenwen, Lei, Jiaming et al.·Experimental and therapeutic medicine·2026

This review examines why people feel extreme fatigue and how doctors can better manage it. The authors explain that fatigue involves problems with how the body makes energy, stress chemicals in the body, and the immune system. They discuss how new technologies and teamwork between different medical specialists—plus telemedicine—can help patients with chronic fatigue syndrome and other conditions feel better.

Energy Metabolism

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Urinary and plasma organic acids and amino acids in chronic fatigue syndrome.

Plasma and urinary carnitine and acylcarnitines in chronic fatigue syndrome.

The distribution of white blood cell fat oxidation in health and disease.

Enterovirus related metabolic myopathy: a postviral fatigue syndrome.

A biochemical analysis of people with chronic fatigue who have Irlen Syndrome: speculation concerning immune system dysfunction.

Integrity of the growth hormone/insulin-like growth factor system is maintained in patients with chronic fatigue syndrome.

Vitamin B status in patients with chronic fatigue syndrome.

Low levels of serum acylcarnitine in chronic fatigue syndrome and chronic hepatitis type C, but not seen in other diseases.

Phosphate diabetes in patients with chronic fatigue syndrome.

A common genetic variant affecting folate metabolism is not over-represented in chronic fatigue syndrome.

Serum carnitine and disabling fatigue in multiple sclerosis.

Preliminary determination of a molecular basis of chronic fatigue syndrome.

Serum levels of carnitine in chronic fatigue syndrome: clinical correlates.

[Effect of warming needle moxibustion on mitochondrial autophagy in rats with chronic fatigue syndrome based on AMPK/ULK1 signaling pathway].

A research perspective on sphingolipid metabolism and myalgic encephalomyelitis/chronic fatigue syndrome.

Exploring a genetic basis for the metabolic perturbations in ME/CFS using UK biobank.

Expert perspectives on Myalgic encephalomyelitis/chronic fatigue syndrome - Insights from the 3rd International Conference of the Charité Fatigue Center.

Indistinguishable mitochondrial phenotypes after exposure of healthy myoblasts to myalgic encephalomyelitis/chronic fatigue syndrome or control serum.

Significant aggravation of pre-existing myalgic encephalomyelitis/chronic fatigue syndrome following proton beam therapy for sphenoid wing meningioma: case report.

Pathophysiological mechanisms of fatigue and multidisciplinary management strategies (Review).

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