Evidence browser

E2 ModerateCohortPEM unclearCase-Control

Can submaximal exercise variables predict peak exercise performance in women with chronic fatigue syndrome?

Nijs, Jo, Demol, Seppe, Wallman, Karen·Archives of medical research·2007

Researchers tested whether measurements taken during moderate-intensity exercise could predict how much energy a person with ME/CFS could produce during their maximum effort. In 222 women with ME/CFS, oxygen use at moderate intensity correlated well with peak oxygen use, but the prediction had too much variation to be reliable for individual patients.

Post-Exertional Malaise

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.

Sleep quality perception in the chronic fatigue syndrome: correlations with sleep efficiency, affective symptoms and intensity of fatigue.

Neu, Daniel, Mairesse, Olivier, Hoffmann, Guy et al.·Neuropsychobiology·2007

ME/CFS patients often report feeling like they have poor sleep quality, even though doctors cannot always find obvious problems when measuring sleep objectively. This study compared how ME/CFS patients and healthy people rated their own sleep quality and found that ME/CFS patients consistently reported worse sleep, despite having similar sleep efficiency measurements. The poor sleep quality perception was somewhat linked to fatigue severity but not related to depression or anxiety symptoms.

Sleep

Prevalence of chronic fatigue syndrome in metropolitan, urban, and rural Georgia.

Reeves, William C, Jones, James F, Maloney, Elizabeth et al.·Population health metrics·2007

This study surveyed over 5,600 people in Georgia to find out how many have ME/CFS. Researchers found that about 2.5% of adults aged 18-59 have the condition, which is higher than estimates from other parts of the United States. Interestingly, the disease affected men and women very differently depending on whether they lived in cities or rural areas.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Assessment of vulvodynia symptoms in a sample of US women: a prevalence survey with a nested case control study.

Arnold, Lauren D, Bachmann, Gloria A, Rosen, Raymond et al.·American journal of obstetrics and gynecology·2007

This study looked at how common vulvodynia (chronic pain in the vulva) is among American women and found that about 4% currently experience it. Women with vulvodynia were more likely to also have other conditions like chronic fatigue syndrome, fibromyalgia, depression, and irritable bowel syndrome. Many women reported that the pain significantly affected their sexual life and daily activities.

Pain and Sensitization

Psychological, medical, and pharmacological correlates of persistent genital arousal disorder.

Leiblum, Sandra, Seehuus, Martin, Goldmeier, David et al.·The journal of sexual medicine·2007

This study surveyed 156 women about persistent genital arousal disorder (PGAD), a condition involving unwanted arousal sensations. Women with full PGAD were more likely to experience depression, anxiety, panic attacks, and chronic fatigue compared to women with milder symptoms or no condition. The researchers suggest that anxiety and worry about these sensations may play a role in making PGAD worse.

E2 ModerateBehavioralPEM unclearCross-Sectional

Complementary and alternative medical therapy utilization by people with chronic fatiguing illnesses in the United States.

Jones, James F, Maloney, Elizabeth M, Boneva, Roumiana S et al.·BMC complementary and alternative medicine·2007

This study looked at how many people with ME/CFS and similar fatiguing illnesses use complementary and alternative medicine (CAM) therapies like massage, chiropractic care, prayer, and other non-conventional treatments. Researchers surveyed over 880 people across the United States and found that people with ME/CFS-like illness were more likely to use body-based therapies (like massage and chiropractic) and mind-body therapies than people without fatigue.

Interventions

Alexithymia in chronic fatigue syndrome: associations with momentary, recall, and retrospective measures of somatic complaints and emotions.

Friedberg, Fred, Quick, Joyce·Psychosomatic medicine·2007

This study looked at whether difficulty identifying and expressing emotions (a trait called alexithymia) is linked to fatigue and pain in ME/CFS patients. Researchers asked 111 people with ME/CFS to report their symptoms three ways: in real-time through daily diaries, in weekly recall, and in overall retrospective ratings over 6 months. The results showed that day-to-day emotional difficulty was not connected to how patients experienced symptoms moment-to-moment, but there was a weak connection to how they remembered pain over longer periods.

Endometriosis is associated with prevalence of comorbid conditions in migraine.

Tietjen, Gretchen E, Bushnell, Cheryl D, Herial, Nabeel A et al.·Headache·2007

This study found that women with migraines who also have endometriosis (a painful condition affecting the uterus) experience more frequent and severe headaches than women with migraines alone. Women with both conditions were also more likely to have other related conditions like chronic fatigue syndrome, anxiety, and bladder pain. The findings suggest these conditions may share common underlying factors, possibly related to hormones.

Pain and Sensitization

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.

E2 ModerateCohortPEM not requiredObservational

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 unclearCross-Sectional

Symptoms of autonomic dysfunction in chronic fatigue syndrome.

Newton, J L, Okonkwo, O, Sutcliffe, K et al.·QJM : monthly journal of the Association of Physicians·2007

This study looked at whether people with ME/CFS have problems with their autonomic nervous system (the part that controls automatic body functions like heart rate and blood pressure). Researchers used a questionnaire called COMPASS to measure autonomic symptoms in ME/CFS patients and healthy controls. They found that autonomic dysfunction symptoms were significantly more common in ME/CFS patients and were linked to how severe their fatigue was.

Autonomic Nervous System

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

Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls.

Wyller, Vegard Bruun, Due, Reidar, Saul, J Philip et al.·The American journal of cardiology·2007

This study tested how the hearts of adolescents with ME/CFS respond to mild physical stress (tilting the body slightly upright for 15 minutes) compared to healthy teenagers. Researchers found that young people with ME/CFS had abnormal heart and blood vessel responses during this test—their hearts beat faster, their blood pressure increased more, and their stroke volume (amount of blood pumped per heartbeat) decreased more than in healthy controls. These differences suggest that ME/CFS involves problems with how the body regulates blood flow and heart function during even mild stress.

Autonomic Nervous System

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

Perception versus polysomnographic assessment of sleep in CFS and non-fatigued control subjects: results from a population-based study.

Majer, Matthias, Jones, James F, Unger, Elizabeth R et al.·BMC neurology·2007

People with ME/CFS commonly report that their sleep doesn't feel refreshing and that they have trouble sleeping, even though standard sleep tests don't always show obvious sleep problems. This study compared how 35 people with ME/CFS and 40 healthy people described their sleep quality against what their actual sleep looked like on overnight sleep monitoring. Interestingly, the sleep recordings looked similar between both groups, but ME/CFS patients were more accurate at noticing their actual sleep behavior, while healthy controls tended to overestimate how long it took them to fall asleep.

Sleep

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

The relative impact of 13 chronic conditions across three different outcomes.

Perruccio, Anthony V, Power, J Denise, Badley, Elizabeth M·Journal of epidemiology and community health·2007

This study looked at how 13 common long-term health conditions—including ME/CFS and fibromyalgia—affect people's daily activities, overall health, and doctor visits. Researchers used information from over 130,000 Canadians and found that ME/CFS and fibromyalgia had the strongest individual impact on activity limitations and poor health ratings, while conditions like arthritis and heart disease affected the most people overall in the population.

Impaired natural immunity, cognitive dysfunction, and physical symptoms in patients with chronic fatigue syndrome: preliminary evidence for a subgroup?

Siegel, Scott D, Antoni, Michael H, Fletcher, Mary Ann et al.·Journal of psychosomatic research·2006

This study looked at whether a specific immune system measure called natural killer cell activity (NKCA) could help identify different subgroups of ME/CFS patients. Researchers compared 41 women with ME/CFS who had low NKCA levels to those with normal levels, measuring their cognitive ability and symptoms. They found that patients with low NKCA reported worse cognitive problems, more daytime dysfunction, and performed worse on thinking tests compared to those with normal NKCA levels.

A first study of cytokine genomic polymorphisms in CFS: Positive association of TNF-857 and IFNgamma 874 rare alleles.

Carlo-Stella, N, Badulli, C, De Silvestri, A et al.·Clinical and experimental rheumatology·2006

This study looked at genetic variations in immune system genes among Italian ME/CFS patients to see if certain genetic patterns might make some people more prone to developing the condition. Researchers found that patients with ME/CFS were more likely to carry specific genetic variants in two genes (TNF and IFNgamma) that are involved in controlling inflammation. These findings suggest that genetic differences might influence how a person's immune system responds and could play a role in ME/CFS development.