ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

3061–3080 of 6,188 studies

E2 ModerateCohortPEM not requiredObservational

Prediction of peak oxygen uptake in patients fulfilling the 1994 CDC criteria for chronic fatigue syndrome.

Nijs, Jo, De Meirleir, Kenny·Clinical rehabilitation·2004

This study looked for a simple way to predict how much oxygen someone with ME/CFS can use during exercise (called VO2peak), which is a measure of exercise capacity. Researchers tested 240 ME/CFS patients on exercise bikes and found that by measuring the maximum workload a patient could achieve, they could estimate their oxygen use fairly accurately with a simple calculation.

E2 ModerateBehavioralPEM not requiredObservational

Kinesiophobia in chronic fatigue syndrome: assessment and associations with disability.

Nijs, Jo, De Meirleir, Kenny, Duquet, William·Archives of physical medicine and rehabilitation·2004

This study looked at whether ME/CFS patients who fear movement (kinesiophobia) have more activity limitations than others. Researchers used a questionnaire to measure fear of movement and found that patients with higher fear of movement reported more difficulty with daily activities, but this fear did not actually relate to how much exercise capacity they had when tested on a bike.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

IgM serum antibodies to Epstein-Barr virus are uniquely present in a subset of patients with the chronic fatigue syndrome.

Lerner, A Martin, Beqaj, Safedin H, Deeter, Robert G et al.·In vivo (Athens, Greece)·2004

Researchers tested blood samples from 58 ME/CFS patients and 68 healthy controls for antibodies to Epstein-Barr virus (EBV), a common virus that causes mononucleosis. They found that about half of the ME/CFS patients (33 out of 58) had elevated levels of a specific type of antibody called IgM against EBV, while none of the healthy controls had this pattern. These antibody levels stayed elevated in ME/CFS patients for up to 3.5 years, suggesting this test might help identify a particular subgroup of ME/CFS patients.

Immune System

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome: lack of association between pain-related fear of movement and exercise capacity and disability.

Nijs, Jo, Vanherberghen, Katrien, Duquet, William et al.·Physical therapy·2004

Many ME/CFS patients with pain avoid movement because they fear it will make them worse (a condition called kinesiophobia). This study tested whether this fear of movement actually relates to how much exercise patients can do or how disabled they are. Researchers found that fear of movement was common in ME/CFS patients, but surprisingly, it did not predict exercise capacity or activity limitations.

E2 ModerateCohortPEM unclearCase-Control

Peripheral cholinergic function in humans with chronic fatigue syndrome, Gulf War syndrome and with illness following organophosphate exposure.

Khan, Faisel, Kennedy, Gwen, Spence, Vance A et al.·Clinical science (London, England : 1979)·2004

Researchers tested how blood vessels in the forearm respond to acetylcholine (a chemical messenger in the body) in people with ME/CFS, Gulf War illness, and pesticide exposure. They found that people with ME/CFS had an unusually strong vascular response to acetylcholine, but people with the other two conditions had normal responses. This suggests ME/CFS may involve a specific problem with how the body breaks down acetylcholine in blood vessels.

Autonomic Nervous System

E2 ModerateCohortPEM not requiredObservational

Disability evaluation in chronic fatigue syndrome: associations between exercise capacity and activity limitations/participation restrictions.

Nijs, J, De Meirleir, K, Wolfs, S et al.·Clinical rehabilitation·2004

This study looked at whether ME/CFS patients with lower exercise capacity also have more difficulty with daily activities. Researchers tested 77 patients on an exercise bike and asked them to report how limited they were in everyday life. They found a modest connection between poor exercise performance and activity limitations, but the link was not strong enough to predict disability from exercise tests alone.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients.

Tritt, Karin, Nickel, Marius, Mitterlehner, Ferdinand et al.·Wiener klinische Wochenschrift·2004

This study looked at 1,000 patients at a hospital clinic to understand why some people with severe, persistent exhaustion become unable to work. The researchers found that patients who couldn't work had stronger focus on physical symptoms, difficulty recognizing their own feelings, and trouble getting along with coworkers—not necessarily because they were sicker, but because of how they coped with their condition.

E2 ModerateCohortPEM not requiredCross-Sectional

Regional distribution of fatiguing illnesses in the United States: a pilot study.

Bierl, Cynthia, Nisenbaum, Rosane, Hoaglin, David C et al.·Population health metrics·2004

Researchers called people across the United States and asked about chronic fatigue lasting at least 6 months. They estimated that about 2.2 million American adults have a condition that looks like ME/CFS based on symptoms alone, without medical testing. The study found that fatiguing illnesses were slightly more common in rural areas than cities, but there were no major differences between different regions of the country.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Chronic fatigue syndrome and sexual dysfunction.

Vermeulen, Ruud C W, Scholte, Hans R·Journal of psychosomatic research·2004

This study examined whether women with ME/CFS experience more sexual problems than healthy women. Researchers surveyed 35 women with ME/CFS and 36 healthy women using questionnaires about fatigue and sexual function. Interestingly, the women with ME/CFS reported similar levels of sexual satisfaction as healthy women, even though they had significantly higher fatigue levels.

E2 ModerateCohortPEM not requiredCross-Sectional

Chronic fatigue syndrome impairs circadian rhythm of activity level.

Tryon, Warren W, Jason, Lenny, Frankenberry, Erin et al.·Physiology & behavior·2004

This study looked at how people with ME/CFS move and rest throughout the day and night by using activity monitors worn on the waist. Researchers found that people with ME/CFS were less active during the day and had less predictable patterns of activity and rest compared to healthy people. These disrupted patterns may help explain why ME/CFS patients experience fatigue and other symptoms.

Sleep

E2 ModerateBehavioralPEM not requiredCross-Sectional

Objective assessment of personality disorder in chronic fatigue syndrome.

Henderson, Max, Tannock, Charles·Journal of psychosomatic research·2004

This study looked at whether people with ME/CFS have personality traits that might be associated with mental health conditions. Researchers interviewed 61 ME/CFS patients, 40 people with depression, and 45 healthy students using a structured clinical assessment tool. They found that 39% of ME/CFS patients had identifiable personality patterns, which was higher than healthy people but lower than those with depression—and importantly, this wasn't simply explained by having depression alongside ME/CFS.

E2 ModerateCohortPEM not requiredCross-Sectional

Sleep assessment in a population-based study of chronic fatigue syndrome.

Unger, Elizabeth R, Nisenbaum, Rosane, Moldofsky, Harvey et al.·BMC neurology·2004

This study looked at sleep problems in 339 people with ME/CFS from Kansas to understand how sleep issues relate to their fatigue. Researchers found that over 80% of ME/CFS patients had at least one sleep problem, with non-restorative sleep (sleep that doesn't feel refreshing) and restlessness being the most common. Interestingly, ME/CFS patients were not unusually sleepy during the day, which suggests their fatigue comes from a different mechanism than typical sleep deprivation.

Sleep

E2 ModerateCohortPEM not requiredCross-Sectional

Salivary cortisol response to awakening in chronic fatigue syndrome.

Roberts, Amanda D L, Wessely, Simon, Chalder, Trudie et al.·The British journal of psychiatry : the journal of mental science·2004

This study tested how well the body's stress response system (controlled by the brain and hormones) works in ME/CFS patients. Researchers measured cortisol, a stress hormone, in saliva when people first woke up and for an hour afterward. They found that people with ME/CFS had a weaker cortisol response compared to healthy people, suggesting their stress-response system may not be working properly.

Endocrine Disruption

E2 ModerateCohortPEM not requiredCase-Control

Gastric emptying is slow in chronic fatigue syndrome.

Burnet, Richard B, Chatterton, Barry E·BMC gastroenterology·2004

This study found that people with ME/CFS often have stomach problems that can be measured with special imaging tests. Researchers compared 32 ME/CFS patients with 45 healthy people and discovered that most ME/CFS patients had slower movement of food through their stomachs, particularly liquids. These measured stomach delays matched up with how severe patients' digestive symptoms were.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Alcohol use in chronic fatigue syndrome.

Woolley, James, Allen, Roz, Wessely, Simon·Journal of psychosomatic research·2004

This study looked at how people with ME/CFS relate to alcohol. Researchers surveyed 114 patients and found that about two-thirds reduced or stopped drinking alcohol after getting ME/CFS. The main reasons were that alcohol made their tiredness worse (67%), caused more nausea (33%), made hangovers worse (23%), and disturbed sleep (24%). Most people made this decision based on their own experience rather than medical advice.

E2 ModerateBehavioralPEM not requiredCase-Control

Physiological responses during a submaximal cycle test in chronic fatigue syndrome.

Wallman, Karen E, Morton, Alan R, Goodman, Carmel et al.·Medicine and science in sports and exercise·2004

This study compared how people with ME/CFS and healthy people without the condition respond to exercise on a stationary bike. The main finding was that people with ME/CFS felt much more exhausted during the same amount of exercise, and they couldn't exercise as hard before becoming tired. Both groups were matched carefully so they had similar activity levels before the study, which makes the comparison more fair.

Post-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

Factors influencing the diagnosis of chronic fatigue syndrome.

Solomon, Laura, Reeves, William C·Archives of internal medicine·2004

Researchers in Wichita, Kansas identified people with ME/CFS symptoms from the general population and found that only 16% had ever been diagnosed with the condition by a doctor. People were more likely to have received a diagnosis if they had moderate income, developed fatigue suddenly, or had tender lymph nodes and sore throat. This suggests that most people with ME/CFS in the community are never formally diagnosed.

Diagnostics

E2 ModerateCohortPEM not requiredCross-Sectional

Factor analysis of symptoms among subjects with unexplained chronic fatigue: what can we learn about chronic fatigue syndrome?

Nisenbaum, Rosane, Reyes, Michele, Unger, Elizabeth R et al.·Journal of psychosomatic research·2004

This study looked at 1,391 people with unexplained chronic fatigue to understand which symptoms tend to occur together. Researchers found that ME/CFS symptoms cluster into three main groups: muscle and joint pain, infection-like symptoms, and problems with thinking, mood, and sleep. Interestingly, people with and without an ME/CFS diagnosis had significant overlap in these symptoms, suggesting that ME/CFS exists on a spectrum rather than as a completely distinct condition.

Diagnostics

E2 ModerateCohortPEM unclearLongitudinal

Childhood predictors of self reported chronic fatigue syndrome/myalgic encephalomyelitis in adults: national birth cohort study.

Viner, Russell, Hotopf, Matthew·BMJ (Clinical research ed.)·2004

This study followed over 11,000 children born in 1970 into adulthood to understand what childhood factors might lead to developing ME/CFS later in life. Researchers found that people who were less active as children, had long-term health conditions in childhood, or were female had higher chances of developing ME/CFS by age 30. Importantly, childhood stress or psychological problems were not found to be risk factors, contrary to some earlier beliefs.

E2 ModerateCohortPEM not requiredLongitudinal

Chronic fatigue syndrome in adolescents: a follow-up study.

Gill, Anna C, Dosen, Ana, Ziegler, John B·Archives of pediatrics & adolescent medicine·2004

This study followed teenagers with severe fatigue for up to 8 years to see how many got better. Teenagers who had been fatigued for less than 6 months all recovered completely. Those diagnosed with ME/CFS had worse outcomes, with less than a quarter showing near-complete improvement, though some did get partially better. Being admitted to the hospital did not change whether teenagers recovered or not.

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Prediction of peak oxygen uptake in patients fulfilling the 1994 CDC criteria for chronic fatigue syndrome.

Kinesiophobia in chronic fatigue syndrome: assessment and associations with disability.

IgM serum antibodies to Epstein-Barr virus are uniquely present in a subset of patients with the chronic fatigue syndrome.

Chronic fatigue syndrome: lack of association between pain-related fear of movement and exercise capacity and disability.

Peripheral cholinergic function in humans with chronic fatigue syndrome, Gulf War syndrome and with illness following organophosphate exposure.

Disability evaluation in chronic fatigue syndrome: associations between exercise capacity and activity limitations/participation restrictions.

Chronic fatigue and indicators of long-term employment disability in psychosomatic inpatients.

Regional distribution of fatiguing illnesses in the United States: a pilot study.

Chronic fatigue syndrome and sexual dysfunction.

Chronic fatigue syndrome impairs circadian rhythm of activity level.

Objective assessment of personality disorder in chronic fatigue syndrome.

Sleep assessment in a population-based study of chronic fatigue syndrome.

Salivary cortisol response to awakening in chronic fatigue syndrome.

Gastric emptying is slow in chronic fatigue syndrome.

Alcohol use in chronic fatigue syndrome.

Physiological responses during a submaximal cycle test in chronic fatigue syndrome.

Factors influencing the diagnosis of chronic fatigue syndrome.

Factor analysis of symptoms among subjects with unexplained chronic fatigue: what can we learn about chronic fatigue syndrome?

Childhood predictors of self reported chronic fatigue syndrome/myalgic encephalomyelitis in adults: national birth cohort study.

Chronic fatigue syndrome in adolescents: a follow-up study.

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