Evidence browser

SleepAutonomic Nervous System

Heart rate variability during sleep and subsequent sleepiness in patients with chronic fatigue syndrome.

Togo, Fumiharu, Natelson, Benjamin H·Autonomic neuroscience : basic & clinical·2013

This study looked at how the heart's rhythm changes during sleep in ME/CFS patients compared to healthy people, and whether these changes relate to feeling more or less tired after sleep. Researchers found that some ME/CFS patients who woke up feeling sleepier had different heart rhythm patterns during deep sleep than healthy controls, even though standard sleep measurements looked normal. This suggests the nervous system's control of the heart during sleep might be disrupted in ME/CFS, which could contribute to unrefreshing sleep.

Subjective sleep quality and daytime sleepiness in a large sample of patients with chronic fatigue syndrome (CFS).

Mariman, A, Vogelaers, D, Hanoulle, I et al.·Acta clinica Belgica·2012

This study looked at sleep problems in 415 ME/CFS patients by asking them to complete questionnaires about sleep quality and daytime sleepiness. The researchers found that ME/CFS patients reported both poor sleep quality and high daytime sleepiness, but these two problems didn't always occur together—some patients had poor sleep quality without feeling sleepy during the day, and a smaller group resembled people with insomnia. The findings suggest that sleep problems in ME/CFS are complex and may affect different patients in different ways.

E2 ModerateCohortPEM not requiredCase-Control

Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study.

Moldofsky, Harvey, Patcai, John·BMC neurology·2011

This study looked at people who had severe SARS infection and were unable to return to work for over a year afterward. These patients experienced long-lasting fatigue, widespread muscle pain, weakness, depression, and poor sleep quality. Researchers found that their sleep patterns and symptoms were very similar to those seen in fibromyalgia and chronic fatigue syndrome.

E2 ModerateCohortPEM not requiredCase-Control

Cognitive impairment in fatigue and sleepiness associated conditions.

Neu, Daniel, Kajosch, Hendrik, Peigneux, Philippe et al.·Psychiatry research·2011

This study compared how fatigue and sleepiness affect thinking and memory. Researchers tested 15 people with ME/CFS, 15 people with sleep apnea, and 16 healthy controls using memory tests, attention tasks, and brain wave measurements. Both patient groups showed cognitive problems, though people with sleep apnea had slightly more difficulty with certain thinking tasks and movement speed.

SleepCognitive Impairment

E2 ModerateCohortPEM unclearCross-Sectional

Sleep-stage dynamics in patients with chronic fatigue syndrome with or without fibromyalgia.

Kishi, Akifumi, Natelson, Benjamin H, Togo, Fumiharu et al.·Sleep·2011

This study looked at sleep patterns in women with ME/CFS, comparing those with ME/CFS alone to those who also have fibromyalgia (FM). Researchers found that people with ME/CFS alone had trouble staying asleep and waking up too often from REM sleep, while those with both conditions showed different sleep problems including difficulty maintaining deeper sleep stages. These findings suggest that ME/CFS and fibromyalgia may involve different types of sleep disturbances.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Long-term sickness absence among patients with chronic fatigue syndrome.

Knudsen, Ann Kristin, Henderson, Max, Harvey, Samuel B et al.·The British journal of psychiatry : the journal of mental science·2011

This study looked at ME/CFS patients who were on long-term sick leave from work and compared them to those still working. Patients taking sick leave had more severe physical fatigue and sleep problems than other patients. Interestingly, those on sick leave also tended to avoid situations they found embarrassing and rested more often as a coping strategy. The researchers suggest that helping patients manage embarrassment-related thoughts and avoidance behaviors might help them return to work.

Characteristics of chronic fatigue syndrome in a Japanese community population : chronic fatigue syndrome in Japan.

Hamaguchi, Masahide, Kawahito, Yutaka, Takeda, Noriyuki et al.·Clinical rheumatology·2011

This Japanese study looked at how many people have ME/CFS in the general population and what their daily habits are like. Researchers found that about 1 in 100 people in Japan have ME/CFS, and people with the condition slept significantly less (about 5.5 hours per night) compared to people without it (about 6.3 hours). The symptom of unrefreshing sleep was particularly useful for identifying who has ME/CFS.

E2 ModerateCohortPEM not requiredCase-Control

Adolescent offspring of mothers with chronic fatigue syndrome.

Smith, Mark S, Buchwald, Dedra S, Bogart, Andy et al.·The Journal of adolescent health : official publication of the Society for Adolescent Medicine·2010

This study looked at whether teenagers whose mothers have ME/CFS are more likely to develop ME/CFS themselves or experience fatigue and other related symptoms. Researchers compared 26 teenagers with mothers who had ME/CFS to 45 teenagers whose mothers were healthy. While teenagers with affected mothers showed higher rates of prolonged fatigue and ME/CFS diagnosis, the differences were small and not statistically proven.

E2 ModerateCohortPEM unclearObservational

A retrospective review of the sleep characteristics in patients with chronic fatigue syndrome and fibromyalgia.

Spitzer, A Robert, Broadman, Melissa·Pain practice : the official journal of World Institute of Pain·2010

Researchers studied sleep patterns in 118 patients with ME/CFS and fibromyalgia using objective sleep tests. They found that most patients had abnormal sleep studies showing excessive daytime sleepiness, and some had sleep features similar to narcolepsy. A genetic marker (HLA DQB1*0602) associated with narcolepsy was found in 43% of patients, much higher than in the general population.

E2 ModerateCohortPEM unclearObservational

Treatment of the narcoleptiform sleep disorder in chronic fatigue syndrome and fibromyalgia with sodium oxybate.

Spitzer, A Robert, Broadman, Melissa·Pain practice : the official journal of World Institute of Pain·2010

Researchers looked at 118 patients with ME/CFS or fibromyalgia who had sleep problems similar to narcolepsy. When these patients were treated with a medication called sodium oxybate, 75% reported significant improvement in fatigue and 60% reported significant improvement in pain. This suggests that fixing the underlying sleep disorder might help relieve both conditions.

Fatigue status in relation to lifestyle in healthy Japanese adolescents.

Zou, Ning, Kubota, Masaru, Kuruma, Eriko et al.·International journal of pediatrics·2010

This study looked at fatigue in over 1,200 healthy Japanese teenagers aged 11–16 to see how common different types of fatigue were and whether lifestyle habits made a difference. Researchers found that girls reported higher fatigue scores related to ME/CFS-type symptoms than boys, and fatigue increased as teenagers got older. Sleep, exercise, diet quality, and sugary drinks were all linked to how tired teenagers felt.

Interstitial cystitis/painful bladder syndrome and associated medical conditions with an emphasis on irritable bowel syndrome, fibromyalgia and chronic fatigue syndrome.

Nickel, J Curtis, Tripp, Dean A, Pontari, Michel et al.·The Journal of urology·2010

This study looked at how often bladder pain syndrome occurs alongside other conditions like irritable bowel syndrome, fibromyalgia, and ME/CFS. Researchers found that people with bladder pain syndrome were much more likely to have these other conditions compared to healthy controls. Importantly, people who had multiple overlapping conditions experienced worse pain, sleep problems, depression, and lower quality of life than those with just one condition.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Physical and psychosocial correlates of severe fatigue in rheumatoid arthritis.

van Hoogmoed, Dewy, Fransen, Jaap, Bleijenberg, Gijs et al.·Rheumatology (Oxford, England)·2010

This study looked at severe fatigue in people with rheumatoid arthritis (RA), a condition that causes joint inflammation. Researchers found that 42% of RA patients experienced severe fatigue that felt frustrating and exhausting. Importantly, this severe fatigue was more closely linked to pain, mood, sleep quality, and how patients thought about their fatigue—rather than to inflammation markers alone.

Electroencephalographic correlates of Chronic Fatigue Syndrome.

Decker, Michael J, Tabassum, Humyra, Lin, Jin-Mann S et al.·Behavioral and brain functions : BBF·2009

This study looked at brain wave patterns during sleep in people with ME/CFS compared to healthy controls using a sleep study test. Researchers found that people with ME/CFS had abnormal brain wave activity during different sleep stages, particularly weaker delta waves during deep sleep and weaker alpha waves during REM sleep. These findings suggest that the problem in ME/CFS may not be the structure of sleep itself, but rather how the brain regulates and maintains restorative sleep.

Replication of an empirical approach to delineate the heterogeneity of chronic unexplained fatigue.

Aslakson, Eric, Vollmer-Conna, Uté, Reeves, William C et al.·Population health metrics·2009

This study looked at nearly 400 women from different parts of Georgia to understand why chronic fatigue affects people so differently. Instead of treating all chronic fatigue as one disease, researchers found that people fall into five distinct groups with different symptom patterns—some with sleep and mood problems, some with weight and metabolic issues, and some without significant fatigue at all. The findings suggest that chronic fatigue is not one-size-fits-all, and doctors may need personalized approaches for different patient groups.

High slow-wave sleep and low-light sleep: chronic fatigue syndrome is not likely to be a primary sleep disorder.

Neu, Daniel, Cappeliez, Bernard, Hoffmann, Guy et al.·Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society·2009

This study compared sleep patterns between people with ME/CFS and people with a primary sleep disorder (sleep apnea) to see if ME/CFS might actually be a sleep problem in disguise. Researchers found that ME/CFS patients have distinctly different sleep patterns—more deep sleep and fewer light sleep stages—compared to people with actual sleep disorders. This suggests ME/CFS is not primarily a sleep disorder, even though both conditions cause people to feel unrefreshed.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Sleep apnea and psychological functioning in chronic fatigue syndrome.

Libman, Eva, Creti, Laura, Baltzan, Marcel et al.·Journal of health psychology·2009

This study looked at whether sleep apnea (a condition where breathing stops and starts during sleep) is common in people with ME/CFS and how it affects mood and psychological well-being. The researchers found that 68% of ME/CFS patients had sleep apnea, but those who did were not significantly more ill than those without it. Both the ME/CFS and sleep apnea groups showed more psychological difficulties than healthy controls, but the researchers suggest these emotional struggles are likely a natural response to living with a chronic illness rather than a separate psychiatric condition.

SleepDiagnostics

Actigraphic assessment of sleep disorders in children with chronic fatigue syndrome.

Ohinata, Junko, Suzuki, Nao, Araki, Akiko et al.·Brain & development·2008

This study examined sleep patterns in 12 children with ME/CFS using a special watch-like device called an actigraph that tracks movement and sleep. Children with ME/CFS slept much longer than healthy children but had lower activity levels and disrupted sleep patterns. The researchers found two main types of sleep problems: some children had very irregular sleep schedules, while others had a delayed sleep phase (sleeping much later than normal).

Dynamics of sleep stage transitions in healthy humans and patients with chronic fatigue syndrome.

Kishi, Akifumi, Struzik, Zbigniew R, Natelson, Benjamin H et al.·American journal of physiology. Regulatory, integrative and comparative physiology·2008

This study examined sleep patterns in people with ME/CFS compared to healthy people by recording brain activity during sleep. Researchers found that people with ME/CFS have disrupted transitions between different types of sleep, particularly trouble maintaining lighter sleep and REM sleep, and instead wake up more frequently. This suggests that the brain's sleep regulation mechanisms work differently in ME/CFS.

Sleep structure and sleepiness in chronic fatigue syndrome with or without coexisting fibromyalgia.

Togo, Fumiharu, Natelson, Benjamin H, Cherniack, Neil S et al.·Arthritis research & therapy·2008

This study looked at sleep patterns in people with ME/CFS, comparing those with and without fibromyalgia to healthy people. Researchers found that ME/CFS patients had worse sleep quality and felt more tired and sleepy after sleeping than healthy controls. The key finding was that some ME/CFS patients experienced frequent sleep interruptions—their sleep kept getting broken up—which made their sleep feel unrefreshing even though they didn't have diagnosable sleep disorders like sleep apnea.