Evidence browser

E2 ModerateCohortPEM not requiredLongitudinal

Exploratory study into the relationship between the symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM) using a quasiexperimental design.

Mckay, Pamela G, Walker, Helen, Martin, Colin R et al.·BMJ open·2021

This study compared people diagnosed with ME/CFS to people diagnosed with fibromyalgia to see if their symptoms were actually similar. The researchers found that both groups experienced pain, fatigue, sleep problems, and impacts on quality of life in very similar ways, suggesting these conditions may share common symptom patterns. The findings suggest that how these conditions are currently diagnosed and treated might need to be reconsidered since patients experience their symptoms so similarly.

Diagnostics

Patient Reported Outcome Measures of Health-Related Quality of Life and Asthenia after Thyroidectomy.

Luddy, Mary Kate, Vetter, Rachel, Shank, Jessica et al.·The Journal of surgical research·2021

Some patients who have their entire thyroid removed experience lasting tiredness and fatigue after surgery, a condition called asthenia. This study followed 182 patients before and after thyroid surgery to measure their quality of life and fatigue levels over one year. Patients who had their entire thyroid removed were much more likely to develop asthenia (42%) compared to those who had only half removed (4%), especially if they had thyroid cancer.

A Comparison of Patients with Chronic Fatigue Syndrome and Myalgic Encephalomyelitis from the United States and Japan.

Wiedbusch, Elzbieta, Cotler, Joseph, Jason, Leonard A·Journal of preventive medicine & healthcare·2021

This study compared how ME/CFS affects people in the United States and Japan by surveying 124 Japanese patients and 210 U.S. patients. The research found that U.S. patients reported more severe brain fog, stomach problems, and exhaustion after activity compared to Japanese patients. Interestingly, Japanese women experienced similar levels of disability as American patients despite being less likely to receive official disability support.

E2 ModerateCohortPEM unclearObservational

Possible involvement of the autonomic nervous system in cervical muscles of patients with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS).

Matsui, Takayoshi, Hara, Kazuhiro, Iwata, Makoto et al.·BMC musculoskeletal disorders·2021

This study looked at 1,226 hospitalized ME/CFS patients who received daily physical therapy focused on neck muscles. About 55% of patients recovered from ME/CFS after this treatment, and those who recovered showed changes in pupil size suggesting their nervous system function improved. The findings suggest that neck muscle problems and nervous system dysfunction may be connected in ME/CFS.

Autonomic Nervous System

E2 ModerateCohortPEM requiredLongitudinal

COVID-19 Symptoms Over Time: Comparing Long-Haulers to ME/CFS.

Jason, Leonard A, Islam, Mohammed, Conroy, Karl et al.·Fatigue : biomedicine, health & behavior·2021

This study compared how symptoms change over time in people with long COVID versus people with ME/CFS. Researchers asked 278 long-haulers to describe their current symptoms and symptoms from about 5 months earlier, and compared them to 502 ME/CFS patients. They found that long-haulers generally improved over time, with better sleep and less post-exertional malaise, but their brain fog and memory problems actually got worse. Long-haulers started off more symptomatic than ME/CFS patients but became less symptomatic over time, though orthostatic symptoms (dizziness when standing) remained similar in both groups.

E2 ModerateCohortPEM requiredCross-Sectional

Hand grip strength and fatigability: correlation with clinical parameters and diagnostic suitability in ME/CFS.

Jäkel, Bianka, Kedor, Claudia, Grabowski, Patricia et al.·Journal of translational medicine·2021

This study tested hand grip strength in ME/CFS patients compared to healthy people and cancer patients to see if it could help diagnose the condition. Researchers found that ME/CFS patients had weaker grip strength and their muscles got tired much faster during repeated squeezing tests. Importantly, their muscles also recovered more slowly after resting for an hour, suggesting that muscle fatigue is a real, measurable feature of ME/CFS.

E2 ModerateCohortPEM unclearCase-Control

Reduced Parasympathetic Reactivation during Recovery from Exercise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Van Oosterwijck, Jessica, Marusic, Uros, De Wandele, Inge et al.·Journal of clinical medicine·2021

This study examined how the nervous system controls heart rate and other body functions in ME/CFS patients compared to healthy people, both at rest and after exercise. Researchers found that while ME/CFS patients had normal nerve function at rest, their bodies had difficulty recovering after exercise—specifically, their parasympathetic nervous system (the 'rest and digest' system) didn't reactivate properly. This delayed recovery is concerning because similar patterns in other diseases are linked to worse health outcomes.

E2 ModerateCohortPEM not requiredObservational

Undetected Jawbone Marrow Defects as Inflammatory and Degenerative Signaling Pathways: Chemokine RANTES/CCL5 as a Possible Link Between the Jawbone and Systemic Interactions?

Lechner, Johann, Schmidt, Marlene, von Baehr, Volker et al.·Journal of inflammation research·2021

This study examined jawbone abnormalities in 301 patients with various chronic illnesses, including ME/CFS. Researchers found that patients with bone loss in the jawbone had elevated levels of a chemical messenger called RANTES/CCL5, which promotes inflammation. These findings were consistent across all disease groups studied, suggesting that jawbone problems may contribute to systemic inflammation in multiple conditions.

Immune System

E2 ModerateCohortPEM requiredCross-Sectional

Post-Acute COVID-19 Symptoms, a Potential Link with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A 6-Month Survey in a Mexican Cohort.

González-Hermosillo, J Antonio, Martínez-López, Jhanea Patricia, Carrillo-Lampón, Sofía Antonieta et al.·Brain sciences·2021

This study followed 130 people recovering from COVID-19 for 6 months to see how many developed symptoms similar to ME/CFS. Nearly half the patients experienced ongoing fatigue, and those with fatigue tended to be older and had spent more time in the hospital. Only 13% of the patients met the strict diagnostic criteria for ME/CFS, suggesting that while some people have overlapping symptoms, post-COVID fatigue and ME/CFS may be distinct conditions.

E2 ModerateBehavioralPEM not requiredLongitudinal

High Prevalence of Perineural Cysts in Patients with Fibromyalgia and Chronic Fatigue Syndrome.

Hulens, Mieke, Bruyninckx, Frans, Dankaerts, Wim et al.·Pain medicine (Malden, Mass.)·2021

Researchers found that small fluid-filled sacs called perineural cysts (Tarlov cysts) near nerve roots in the spine were present in 39% of patients diagnosed with fibromyalgia or ME/CFS—three times more common than in the general population. These cysts may irritate nerves and could potentially explain why some patients with these conditions experience widespread pain and fatigue. This finding suggests that fibromyalgia, ME/CFS, and symptomatic Tarlov cysts might share a similar underlying cause related to spinal fluid pressure.

Pain and Sensitization

The association between exposure to domestic abuse in women and the development of syndromes indicating central nervous system sensitization: A retrospective cohort study using UK primary care records.

Chandan, Joht Singh, Keerthy, Deepiksana, Gokhale, Krishna Margadhamane et al.·European journal of pain (London, England)·2021

This study looked at whether women who experienced domestic abuse were more likely to develop conditions involving chronic pain and nervous system sensitivity, such as fibromyalgia and ME/CFS. Researchers compared health records of over 22,000 women who had experienced abuse with nearly 45,000 women who had not. They found that abuse survivors had significantly higher rates of several pain-related conditions, suggesting that trauma may trigger or worsen these syndromes.

Pain and Sensitization

E2 ModerateCohortPEM unclearObservational

Evaluating Routine Blood Tests According to Clinical Symptoms and Diagnostic Criteria in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Baklund, Ingrid H, Dammen, Toril, Moum, Torbjørn Åge et al.·Journal of clinical medicine·2021

Researchers compared blood test results from 149 ME/CFS patients with 264 healthy people to look for differences. They found that ME/CFS patients had higher levels of inflammation markers and certain blood cells, along with lower potassium and muscle enzyme levels. These differences suggest that ME/CFS may involve both inflammation and possible muscle or metabolic problems.

Immune System

Delineating the Association Between Soluble CD26 and Autoantibodies Against G-Protein Coupled Receptors, Immunological and Cardiovascular Parameters Identifies Distinct Patterns in Post-Infectious vs. Non-Infection-Triggered Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Szklarski, Marvin, Freitag, Helma, Lorenz, Sebastian et al.·Frontiers in immunology·2021

This study looked at a protein called sCD26 in people with ME/CFS to understand how it relates to immune system problems and heart function issues. Researchers found that people with ME/CFS triggered by an infection had different patterns of immune problems linked to low sCD26 levels compared to people whose ME/CFS started without an infection. The findings suggest that infection-related and non-infection-related ME/CFS may involve different biological mechanisms.

Immune System

E2 ModerateCohortPEM unclearObservational

[Individuals with sub-health status have obviously unbalanced structure of the intestinal flora: analysis of 150 nursing staff members].

Zhang, X, Cai, W, Liao, S et al.·Nan fang yi ke da xue xue bao = Journal of Southern Medical University·2021

This study compared the gut bacteria of 75 nursing staff members with sub-health status (feeling unwell without a specific diagnosis) to 75 healthy staff members. Researchers found that people with sub-health status had a different balance of gut bacteria compared to healthy people, with greater diversity in bacterial types but an overall imbalance in their gut microbial community.

Warning Signals of Post-Exertional Malaise in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Retrospective Analysis of 197 Patients.

Ghali, Alaa, Lacout, Carole, Ghali, Maria et al.·Journal of clinical medicine·2021

This study looked at whether certain new or unusual symptoms might warn ME/CFS patients that a post-exertional malaise (PEM) flare is coming. Researchers reviewed medical records from 197 ME/CFS patients and found that about 14% experienced mood changes or other new symptoms before their baseline symptoms got worse. Interestingly, these patients had less intense PEM flares than those without warning symptoms, suggesting these early signals might help patients prepare or prevent more severe crashes.

E2 ModerateCohortPEM requiredCross-Sectional

The Epidemiology of Insomnia and Sleep Duration Across Mental and Physical Health: The SHoT Study.

Sivertsen, Børge, Hysing, Mari, Harvey, Allison G et al.·Frontiers in psychology·2021

This study looked at sleep problems in over 50,000 Norwegian college students and found that insomnia (difficulty sleeping) is much more common in people with both mental and physical health conditions. Students with ME/CFS had particularly high rates of insomnia—about 65% of women and an unspecified percentage of men experienced insomnia when they also had ME/CFS. The study also found that people with these conditions slept shorter amounts overall.

Sleep

Comparing Idiopathic Chronic Fatigue and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in Males: Response to Two-Day Cardiopulmonary Exercise Testing Protocol.

van Campen, C Linda M C, Visser, Frans C·Healthcare (Basel, Switzerland)·2021

This study compared how men with ME/CFS respond to exercise testing on two consecutive days versus men with chronic fatigue that doesn't meet ME/CFS criteria. When ME/CFS patients exercised on the second day, they performed worse and couldn't reach the same levels they achieved on day one. Men with chronic fatigue (but not ME/CFS) actually improved on day two, similar to healthy people.

E2 ModerateCohortPEM not requiredCase-Control

Rome IV Functional Gastrointestinal Disorders and Health Impairment in Subjects With Hypermobility Spectrum Disorders or Hypermobile Ehlers-Danlos Syndrome.

Lam, Ching Y, Palsson, Olafur S, Whitehead, William E et al.·Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association·2021

This study compared stomach and digestive problems in people with hypermobility disorders (including hypermobile Ehlers-Danlos Syndrome) to a general population. Nearly all people with these hypermobility conditions (98%) had one or more functional gastrointestinal disorder, compared to less than half of the comparison group. People with hypermobility disorders also experienced many other widespread body symptoms and used healthcare services much more frequently.

Potential role of microbiome in Chronic Fatigue Syndrome/Myalgic Encephalomyelits (CFS/ME).

Lupo, Giuseppe Francesco Damiano, Rocchetti, Gabriele, Lucini, Luigi et al.·Scientific reports·2021

This study looked at the bacteria living in the gut and mouth of people with ME/CFS compared to healthy people. Researchers found that people with ME/CFS have different types and amounts of bacteria in their intestines, including fewer beneficial bacteria and more of certain harmful ones. They also found differences in the chemical makeup of patients' stool samples. These differences suggest that gut bacteria imbalance may play a role in ME/CFS, though scientists don't yet know if this is a cause or a result of the illness.