Evidence browser

E2 ModerateDiagnosticPEM unclearMethods-Paper

Contrasting case definitions for chronic fatigue syndrome, Myalgic Encephalomyelitis/chronic fatigue syndrome and myalgic encephalomyelitis.

Jason, Leonard A, Brown, Abigail, Clyne, Erin et al.·Evaluation & the health professions·2012

This study looked at patients diagnosed with chronic fatigue syndrome (CFS) using an older definition and compared how many of them would also meet two newer, stricter definitions: ME/CFS and ME. Researchers found that patients meeting the newer, stricter definitions had more severe symptoms and greater disability than those who only met the older CFS definition. This suggests that the newer definitions may help doctors identify the most severely affected patients.

Diagnostics

Data mining: comparing the empiric CFS to the Canadian ME/CFS case definition.

Jason, Leonard A, Skendrovic, Beth, Furst, Jacob et al.·Journal of clinical psychology·2012

This study compared two different sets of diagnostic criteria used to identify ME/CFS patients. Researchers used a computer-based analysis technique to test which questions from patient surveys were most helpful in accurately diagnosing the illness. They found that the Canadian criteria correctly identified 87% of ME/CFS patients, while the older empiric criteria identified about 79%, suggesting the Canadian approach may be more effective for diagnosis.

Diagnostics

Heterogeneous nuclear RNPs as targets of autoantibodies in systemic rheumatic diseases.

Op De Beéck, Katrijn, Maes, Liesbeth, Van den Bergh, Karolien et al.·Arthritis and rheumatism·2012

This study looked for specific autoantibodies (immune proteins that attack the body's own cells) in people with various rheumatic diseases, including those with chronic fatigue syndrome. Researchers tested blood samples from hundreds of patients and healthy controls, measuring antibodies against different protein targets called hnRNPs. They found that people with Sjögren's syndrome (an autoimmune disease affecting glands) had significantly more of these antibodies compared to healthy people.

E2 ModerateCohortPEM not requiredObservational

Prevalence, incidence, and classification of chronic fatigue syndrome in Olmsted County, Minnesota, as estimated using the Rochester Epidemiology Project.

Vincent, Ann, Brimmer, Dana J, Whipple, Mary O et al.·Mayo Clinic proceedings·2012

This study looked at how many people in one county had ME/CFS by reviewing medical records from 1998-2002. Researchers found that about 71 out of every 100,000 people had ME/CFS, and about 13 out of every 100,000 per year were newly diagnosed. Importantly, they discovered that 70% of people initially suspected of having ME/CFS actually had other medical conditions that explained their fatigue instead.

Diagnostics

E2 ModerateCohortPEM not requiredObservational

Comparison of chronic fatigue syndrome/myalgic encephalopathy with other disorders: an observational study.

Knudsen, Ak, Lervik, Lv, Harvey, Sb et al.·JRSM short reports·2012

Researchers looked at how many people were using online discussion forums for different health conditions in Norway in 2009. They found that ME/CFS forums were far more active than forums for other illnesses—with more users and more messages posted relative to how many people have the condition. This high activity might mean that people with ME/CFS are seeking answers and support online, especially since the condition is poorly understood and sometimes stigmatized.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Psycho-physiological impact on women with chronic fatigue syndrome in the context of their couple relationship.

Blazquez, Alicia, Guillamó, Elisabeth, Alegre, José et al.·Psychology, health & medicine·2012

This study looked at how relationship satisfaction and anxiety may affect the physical symptoms of ME/CFS in women. Researchers asked 40 women with ME/CFS and their partners about their relationship quality and anxiety levels, then measured how women's hearts and breathing responded at rest and during very gentle exercise. They found that anxiety and relationship satisfaction seemed to connect with how their bodies responded physically.

Prevalence of xenotropic murine leukemia virus-related virus infection in different risk populations in Spain.

Arredondo, Miguel, Hackett, John, de Bethencourt, Fermín R et al.·AIDS research and human retroviruses·2012

Researchers tested blood samples from over 1,100 people in Spain, including those with ME/CFS and fibromyalgia, to look for a virus called XMRV that had been suggested as a possible cause of these conditions. They found no reliable evidence that XMRV was present in any of the groups they studied, including people with ME/CFS, cancer, other viral infections, or healthy blood donors.

The financial and psychological impacts on mothers of children with chronic fatigue syndrome (CFS/ME).

Missen, A, Hollingworth, W, Eaton, N et al.·Child: care, health and development·2012

This study looked at how having a child with ME/CFS affects mothers' finances and mental health. Researchers surveyed 40 mothers and interviewed 8 in depth, finding that most families lost money each month and spent more on care, while three-quarters of mothers showed signs of depression or anxiety—much higher than the general population.

E2 ModerateCohortPEM not requiredObservational

Mitochondrial dysfunction and the pathophysiology of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Booth, Norman E, Myhill, Sarah, McLaren-Howard, John·International journal of clinical and experimental medicine·2012

This study tested whether ME/CFS fatigue is caused by problems with how cells produce energy. Researchers measured energy production in immune cells from 138 ME/CFS patients and compared them to healthy controls, finding that all patients had measurable problems with their cellular energy factories (mitochondria) that matched how sick they felt. The study also found signs of tissue damage in the blood, suggesting these energy problems affect many cells throughout the body.

Energy Metabolism

Predictors of Fatigue among Patients with Chronic Fatigue Syndrome.

Jason, Leonard A, Brown, Molly, Evans, Meredyth et al.·Journal Of Human Behavior In The Social Environment·2012

This study asked ME/CFS patients to keep detailed activity logs to understand what triggers their fatigue. Researchers looked at what patients were doing, what they had been doing 30 minutes earlier, and their fatigue levels to find patterns. The study suggests that tracking daily activities can help doctors and patients see which activities are most connected to fatigue flare-ups.

E2 ModerateCohortPEM not requiredLongitudinal

Understanding long-term outcomes of chronic fatigue syndrome.

Brown, Molly M, Bell, David S, Jason, Leonard A et al.·Journal of clinical psychology·2012

This study followed people who were diagnosed with ME/CFS 25 years earlier and compared them to healthy people. Most participants (20 out of 25) no longer had an ME/CFS diagnosis, but surprisingly, they still experienced significantly more health problems and limitations than healthy controls. This suggests that even when people stop meeting the criteria for ME/CFS, they may not fully recover to their previous level of health.

E2 ModerateCohortPEM unclearCase-Control

Responses to exercise differ for chronic fatigue syndrome patients with fibromyalgia.

Cook, Dane B, Stegner, Aaron J, Nagelkirk, Paul R et al.·Medicine and science in sports and exercise·2012

This study compared how the bodies of ME/CFS patients respond to moderate exercise on a stationary bike. Researchers found that patients who have both ME/CFS and fibromyalgia (a condition causing widespread pain) showed different heart and breathing responses during exercise compared to healthy people, including higher perceived effort and different blood pressure patterns.

Post-Exertional Malaise

E2 ModerateCohortPEM unclearLongitudinal

Longitudinal investigation of natural killer cells and cytokines in chronic fatigue syndrome/myalgic encephalomyelitis.

Brenu, Ekua W, van Driel, Mieke L, Staines, Donald R et al.·Journal of translational medicine·2012

This study tracked immune system changes in 65 people with ME/CFS over one year, comparing them to 21 healthy controls. Researchers found that people with ME/CFS had consistently lower natural killer (NK) cell activity—immune cells that help fight infections—throughout the year. They also found changes in inflammatory molecules called cytokines that fluctuated at different time points.

No evidence for xenotropic murine leukemia-related virus infection in Sweden using internally controlled multiepitope suspension array serology.

Blomberg, Jonas, Blomberg, Fredrik, Sjösten, Anna et al.·Clinical and vaccine immunology : CVI·2012

Researchers tested blood samples from ME/CFS patients and healthy blood donors to see if they had been infected with a mouse virus called XMRV, which had been proposed as a possible cause of ME/CFS. Using a sensitive new testing method that looked for multiple signs of XMRV infection, they found no difference in viral markers between the two groups, suggesting XMRV is not associated with ME/CFS.

Evidence for inflammation and activation of cell-mediated immunity in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): increased interleukin-1, tumor necrosis factor-α, PMN-elastase, lysozyme and neopterin.

Maes, Michael, Twisk, Frank N M, Kubera, Marta et al.·Journal of affective disorders·2012

This study examined whether people with ME/CFS have higher levels of inflammatory markers—substances in the blood that signal inflammation—compared to healthy people and those with regular fatigue. Researchers found that ME/CFS patients had significantly elevated levels of five different inflammatory markers, and these markers were linked to common ME/CFS symptoms like fatigue, brain fog, and flu-like feelings. The findings suggest that low-grade inflammation in the body may be contributing to ME/CFS symptoms.

Do you think it's a disease? a survey of medical students.

Erueti, Chrissy, Glasziou, Paul, Mar, Chris Del et al.·BMC medical education·2012

This study asked medical students whether various health conditions should be classified as a 'disease' or not. Interestingly, when the same condition was given a more medical-sounding name (like 'myalgic encephalomyelitis') versus a simpler name (like 'chronic fatigue syndrome'), students were more likely to call it a disease. This suggests that the words doctors use to describe an illness can influence how seriously it is viewed, even when describing the exact same condition.

NMR metabolic profiling of serum identifies amino acid disturbances in chronic fatigue syndrome.

Armstrong, Christopher W, McGregor, Neil R, Sheedy, John R et al.·Clinica chimica acta; international journal of clinical chemistry·2012

Researchers used a specialized blood test called NMR to compare the levels of different chemicals in the blood of 11 people with ME/CFS and 10 healthy people. They found that people with ME/CFS had significantly lower levels of two amino acids (building blocks of protein): glutamine and ornithine. These findings suggest that people with ME/CFS may have problems with how their bodies process certain proteins and manage nitrogen, which are important for energy and cell function.

Biomarkers

E2 ModerateCohortPEM not requiredCase-Control

Neurohumoral and haemodynamic profile in postural tachycardia and chronic fatigue syndromes.

Okamoto, Luis E, Raj, Satish R, Peltier, Amanda et al.·Clinical science (London, England : 1979)·2012

This study looked at patients with POTS (a condition where heart rate increases too much when standing) to see how many also have ME/CFS and whether they are different from POTS patients without ME/CFS. The researchers found that most POTS patients experience severe fatigue, and about two-thirds also meet ME/CFS criteria. Those with both conditions had stronger heart rate increases when standing and signs of greater stress hormone activity.

Autonomic Nervous System

Loss of capacity to recover from acidosis on repeat exercise in chronic fatigue syndrome: a case-control study.

Jones, David E J, Hollingsworth, Kieren G, Jakovljevic, Djordje G et al.·European journal of clinical investigation·2012

This study looked at how muscles produce and use energy during exercise in ME/CFS patients compared to healthy people. Researchers found that ME/CFS patients' muscles became more acidic (like buildup of lactic acid) during exercise and took much longer to recover back to normal levels, even after repeated exercise sessions. This abnormal response to exercise may explain why some ME/CFS patients feel worse after exertion rather than better.

Post-Exertional Malaise