Evidence browser

Functioning in individuals with chronic fatigue syndrome: increased impairment with co-occurring multiple chemical sensitivity and fibromyalgia.

Brown, Molly M, Jason, Leonard A·Dynamic medicine : DM·2007

This study looked at 114 people with ME/CFS to see how often they also had fibromyalgia or multiple chemical sensitivity, and whether having more than one condition made their symptoms worse. The researchers found that about 44% had ME/CFS alone, while others had it combined with one or both of the other conditions. People with all three conditions were the most disabled and had the hardest time with daily activities compared to those with ME/CFS alone.

Decreased expression of CD69 in chronic fatigue syndrome in relation to inflammatory markers: evidence for a severe disorder in the early activation of T lymphocytes and natural killer cells.

Mihaylova, Ivana, DeRuyter, Marcel, Rummens, Jean-Luc et al.·Neuro endocrinology letters·2007

This study looked at immune cell activation in people with ME/CFS by measuring a protein called CD69 on the surface of immune cells. Researchers found that ME/CFS patients had significantly lower levels of this activation marker on their T cells and natural killer cells compared to healthy people, even though the total number of immune cells was normal. This suggests that immune cells in ME/CFS may have trouble becoming activated properly in response to challenges.

E2 ModerateBehavioralPEM not requiredLongitudinal

[Course, consequences and treatment of prolonged fatigue among workers: an overview of findings from the Maastricht Cohort Study].

Kant, Ij, Jansen, N W H, van Amelsvoort, L G P M et al.·Tijdschrift voor psychiatrie·2007

This study followed over 12,000 workers for 4 years to understand how prolonged fatigue develops and affects people's lives. Researchers found that fatigue often lasts a long time and can lead to serious problems like missed work, job loss, and weakened immunity. When doctors tried treating fatigue with brief talk therapy, it did not help.

A twin study of cognitive function in chronic fatigue syndrome: the effects of sudden illness onset.

Claypoole, Keith H, Noonan, Carolyn, Mahurin, Roderick K et al.·Neuropsychology·2007

This study compared 22 pairs of identical twins where one had ME/CFS and the other was healthy. Researchers gave both twins thinking and memory tests to see if ME/CFS affects the brain. Twins with ME/CFS had slower processing speed, weaker verbal memory, slower motor responses, and more difficulty with complex thinking tasks, even though they had the same genetic background as their healthy twin.

Cognitive Impairment

beta-Alanine and gamma-aminobutyric acid in chronic fatigue syndrome.

Hannestad, Ulf, Theodorsson, Elvar, Evengård, Birgitta·Clinica chimica acta; international journal of clinical chemistry·2007

Researchers measured two brain chemicals (GABA and beta-alanine) in the urine of ME/CFS patients and healthy people to see if abnormal levels might explain fatigue and sleep problems. They found no overall difference between patients and controls, but a small subgroup of ME/CFS patients (4 out of 33) had unusually high beta-alanine levels, suggesting this chemical imbalance might affect some—but not all—people with ME/CFS.

The experience of cancer-related fatigue and chronic fatigue syndrome: a qualitative and comparative study.

Bennett, Barbara, Goldstein, David, Friedlander, Michael et al.·Journal of pain and symptom management·2007

This study compared how fatigue affects women with cancer-related fatigue (after breast cancer treatment) versus women with ME/CFS. Both groups described very similar experiences: exhaustion, problems with thinking and memory, and mood changes. Women with ME/CFS also reported muscle pain and flu-like symptoms more often. The researchers found that these two conditions share a common set of disabling symptoms, suggesting they may involve similar underlying causes despite different triggers.

Cognitive Impairment

Reduced levels of oestrogen receptor beta mRNA in Swedish patients with chronic fatigue syndrome.

Gräns, Hanna, Nilsson, Maria, Dahlman-Wright, Karin et al.·Journal of clinical pathology·2007

This study looked at a protein called estrogen receptor beta in immune cells from ME/CFS patients and healthy people. Researchers found that ME/CFS patients had lower levels of this protein compared to healthy controls. Since estrogen plays a role in immune function and ME/CFS affects more women than men, this finding suggests hormone-related immune problems might be involved in the disease.

E2 ModerateCohortPEM not requiredLongitudinal

Cortisol and severe fatigue: a longitudinal study in adolescent girls.

Ter Wolbeek, Maike, van Doornen, Lorenz J P, Coffeng, Luc E et al.·Psychoneuroendocrinology·2007

This study looked at whether girls with severe, ongoing fatigue have different stress hormone (cortisol) levels than girls without fatigue. Researchers tested cortisol levels at different times over a year and found that while fatigued girls reported much worse symptoms overall, their cortisol levels were actually normal and similar to non-fatigued girls. This suggests that severe fatigue in adolescents may not be caused by problems with how the body manages stress hormones.

Endocrine Disruption

Increased serum IgA and IgM against LPS of enterobacteria in chronic fatigue syndrome (CFS): indication for the involvement of gram-negative enterobacteria in the etiology of CFS and for the presence of an increased gut-intestinal permeability.

Maes, Michael, Mihaylova, Ivana, Leunis, Jean-Claude·Journal of affective disorders·2007

This study found that people with ME/CFS have higher levels of immune antibodies (IgA and IgM) that react against bacteria normally found in the gut. The researchers suggest this indicates the gut barrier may be more permeable (leaky), allowing bacterial products to enter the bloodstream and trigger an immune response. The study suggests testing for these antibodies might help identify and treat this potential gut problem in ME/CFS patients.

E2 ModerateCohortPEM not required

Characteristics of the formation of chronic fatigue syndrome and approaches to its treatment in young patients with focal brain damage.

Boiko, A N, Batysheva, T T, Matvievskaya, O V et al.·Neuroscience and behavioral physiology·2007

This study looked at why people with brain injuries (from multiple sclerosis, stroke, infection, or trauma) develop severe fatigue. Researchers tested 50 patients and gave half of them a medication called Fezam to see if it would help. The medication reduced fatigue symptoms, especially in MS patients, with few side effects.

Interventions

SleepAutonomic Nervous System

Higher heart rate and reduced heart rate variability persist during sleep in chronic fatigue syndrome: a population-based study.

Boneva, Roumiana S, Decker, Michael J, Maloney, Elizabeth M et al.·Autonomic neuroscience : basic & clinical·2007

This study found that people with ME/CFS have a faster heart rate and less heart rate variability (natural changes in heartbeat speed) during sleep compared to healthy people. These differences suggest that the nervous system in ME/CFS patients stays more activated even during sleep, which may be related to chemical imbalances in the body.

Prevalence of clinically significant functional fatigue or weakness in specialty outpatient clinics of Pune, India.

Paralikar, Vasudeo, Agashe, Mohan, Oke, Meera et al.·Journal of the Indian Medical Association·2007

This study looked at how common significant fatigue and weakness are in hospital outpatient clinics in Pune, India. Researchers surveyed nearly 1,900 patients across four different specialty clinics and found that about 5% experienced clinically significant fatigue or weakness. Women were more likely to have this condition than men, and it was more common in dermatology and traditional medicine clinics than in psychiatry or general medicine clinics.

E2 ModerateCohortPEM not requiredObservational

Publication trends in chronic fatigue syndrome: comparisons with fibromyalgia and fatigue: 1995-2004.

Friedberg, Fred, Sohl, Stephanie, Schmeizer, Brett·Journal of psychosomatic research·2007

This study looked at how many scientific articles about ME/CFS were published between 1995 and 2004, and compared this to articles about fibromyalgia and fatigue. The researchers found that while articles about fibromyalgia and general fatigue increased significantly during this decade, the number of ME/CFS articles stayed relatively flat. This suggests that ME/CFS was not receiving growing research attention compared to similar conditions.

Actuarial analysis of private payer administrative claims data for women with endometriosis.

Mirkin, David, Murphy-Barron, Carrieann, Iwasaki, Kosuke·Journal of managed care pharmacy : JMCP·2007

This study looked at insurance claims from nearly 4 million people to understand how common endometriosis is and how much it costs to treat. Researchers found that women with endometriosis spend significantly more on medical care than other women, have frequent hospital stays and surgeries, and often have other health conditions at the same time—including chronic fatigue syndrome. The study shows endometriosis is a serious, expensive condition that affects many aspects of a woman's health.

E2 ModerateCohortPEM unclearCase-Control

Not in the mind but in the cell: increased production of cyclo-oxygenase-2 and inducible NO synthase in chronic fatigue syndrome.

Maes, Michael, Mihaylova, Ivana, Kubera, Marta et al.·Neuro endocrinology letters·2007

This study found that people with ME/CFS have higher levels of two inflammatory molecules (COX-2 and iNOS) in their white blood cells compared to healthy people. The levels of these inflammatory markers were directly linked to how severe their symptoms were, including fatigue, pain, brain fog, and feeling like they have an infection. This suggests ME/CFS involves real inflammation in the body, not just psychological factors.

E2 ModerateBehavioralPEM not requiredCross-Sectional

The impact of informational interventions about cognitive behavioral therapy for chronic fatigue syndrome on GPs referral behavior.

Scheeres, Korine, Wensing, Michel, Mes, Carola et al.·Patient education and counseling·2007

This study looked at whether giving doctors written information about cognitive behavioral therapy (CBT) as a treatment for ME/CFS would encourage them to refer their patients to try it. Researchers surveyed over 300 general practitioners and found that most who received the information remembered it and had better understanding of ME/CFS. About 22% of the doctors ended up referring at least one patient for CBT treatment during the study period.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Screening for psychological distress using internet administration of the Hospital Anxiety and Depression Scale (HADS) in individuals with chronic fatigue syndrome.

McCue, Patricia, Buchanan, Tom, Martin, Colin R·The British journal of clinical psychology·2006

This study tested whether an online questionnaire called the HADS (Hospital Anxiety and Depression Scale) accurately measures anxiety and depression in people with ME/CFS. Researchers found that people with ME/CFS did have higher anxiety and depression scores than healthy controls, but the online format may have artificially inflated these scores. The questionnaire appears useful for screening but measures three different aspects of emotional distress rather than just two as previously thought.

Chronic widespread pain and its comorbidities: a population-based study.

Kato, Kenji, Sullivan, Patrick F, Evengård, Birgitta et al.·Archives of internal medicine·2006

This large study of over 44,000 Swedish adults found that chronic widespread pain (a hallmark of fibromyalgia) occurs together with ME/CFS, joint pain, depression, and irritable bowel syndrome much more often than by chance alone. Interestingly, when researchers compared twins, they discovered that shared family genes and home environment—not just the pain condition itself—explained much of why these conditions cluster together.

Generalized joint hypermobility is more common in chronic fatigue syndrome than in healthy control subjects.

Nijs, Jo, Aerts, Annemie, De Meirleir, Kenny·Journal of manipulative and physiological therapeutics·2006

This study found that people with ME/CFS are about 5 times more likely than healthy people to have loose, overly flexible joints (joint hypermobility). Researchers tested 68 ME/CFS patients and 69 healthy volunteers using physical exams and knee movement tests. Most ME/CFS patients in the study had joint hypermobility, but surprisingly, this looseness did not seem to be connected to how much pain they experienced.