Evidence browser

Comparison of heart rate variability in patients with chronic fatigue syndrome and controls.

Yataco, A, Talo, H, Rowe, P et al.·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·1997

Researchers tested whether ME/CFS patients have problems with their autonomic nervous system (the system that automatically controls heart rate, blood pressure, and other vital functions). They measured heart rate variability—natural variations in heart rate—in ME/CFS patients and healthy controls while lying down and standing up. They found that the heart rate patterns were similar between the two groups both at rest and when standing, suggesting that basic autonomic function may not be obviously different in ME/CFS.

E2 ModerateCohortPEM not requiredLongitudinal

The natural history of concurrent sick building syndrome and chronic fatigue syndrome.

Chester, A C, Levine, P H·Journal of psychiatric research·1997

This study followed 23 people who developed fatigue and other symptoms during an outbreak linked to a problem building environment. Four years later, about two-thirds of the group had improved significantly or felt much better, while about one-third remained quite ill and unable to work. People who improved tended to also see their respiratory symptoms, sore throats, and headaches get better over time.

E2 ModerateCohortPEM unclearCross-Sectional

An investigation of sympathetic hypersensitivity in chronic fatigue syndrome.

Sendrowski, D P, Buker, E A, Gee, S S·Optometry and vision science : official publication of the American Academy of Optometry·1997

Researchers tested whether ME/CFS patients have unusually sensitive nerves that control pupil size, similar to what is seen in fibromyalgia. They applied eye drops to 29 ME/CFS patients and 33 healthy controls and measured how much the pupils dilated. The results showed no significant difference between the two groups, suggesting that ME/CFS patients do not have this type of nerve sensitivity.

E2 ModerateCohortPEM not requiredObservational

[Demonstration on Borna disease virus in patients with chronic fatigue syndrome].

Nakaya, T, Kuratsune, H, Kitani, T et al.·Nihon rinsho. Japanese journal of clinical medicine·1997

Researchers tested whether a virus called Borna disease virus (BDV) might be connected to ME/CFS. They found that some patients with ME/CFS had signs of BDV infection, and the virus was also detected in one family where multiple members had ME/CFS. While these findings suggest BDV could play a role, the study shows it's likely not the sole cause of ME/CFS.

The quality of life of persons with chronic fatigue syndrome.

Anderson, J S, Ferrans, C E·The Journal of nervous and mental disease·1997

This study asked 110 people with ME/CFS to rate their quality of life and interviewed 22 of them in depth about their daily experiences. The researchers found that people with ME/CFS reported significantly lower quality of life compared to people with other chronic illnesses, with the biggest problems in health and physical functioning. The detailed interviews helped explain why the numbers were so low and showed that ME/CFS uniquely disrupts many aspects of a person's life.

E2 ModerateBehavioralPEM not requiredCross-Sectional

An epidemiologic study of fatigue with relevance for the chronic fatigue syndrome.

Fukuda, K, Dobbins, J G, Wilson, L J et al.·Journal of psychiatric research·1997

Researchers surveyed nearly 1,700 households across four rural Michigan communities to investigate reports of a cluster of chronic fatigue syndrome cases. They found that fatigue was equally common across all communities studied, and the symptoms people with fatigue experienced were similar to generic tiredness rather than distinctly different. The reported cluster of CFS cases could not be confirmed.

Physical fatigability and exercise capacity in chronic fatigue syndrome: association with disability, somatization and psychopathology.

Fischler, B, Dendale, P, Michiels, V et al.·Journal of psychosomatic research·1997

This study looked at how people with ME/CFS respond to exercise by measuring whether they can reach their target heart rate during activity. Researchers found that many patients don't reach expected heart rates and that this relates to how disabled they feel in daily life. Interestingly, anxiety and depression didn't explain why people avoided strenuous exercise, suggesting that avoidance behavior in ME/CFS may have different causes than in other conditions.

Post-Exertional Malaise

Does the chronic fatigue syndrome involve the autonomic nervous system?

Freeman, R, Komaroff, A L·The American journal of medicine·1997

This study tested whether ME/CFS patients have problems with their autonomic nervous system—the part of the nervous system that controls automatic functions like heart rate and blood pressure. Researchers found that ME/CFS patients had abnormal heart rate and blood pressure responses during standing and tilting tests, and their nervous system wasn't regulating these responses properly. The findings suggest that either deconditioning from reduced activity, a viral infection damaging the nervous system, or both could explain why many ME/CFS patients feel dizzy or faint when standing up.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Latent variable models of functional somatic distress.

Robbins, J M, Kirmayer, L J, Hemami, S·The Journal of nervous and mental disease·1997

This study looked at how symptoms of ME/CFS, fibromyalgia, and irritable bowel syndrome relate to each other in nearly 700 patients visiting family medicine clinics. Using statistical methods, researchers found evidence that these conditions may be distinct from one another, rather than being different expressions of the same underlying problem. The findings suggest that depression and anxiety may play a role alongside these syndromes.

High frequency of autoantibodies to insoluble cellular antigens in patients with chronic fatigue syndrome.

von Mikecz, A, Konstantinov, K, Buchwald, D S et al.·Arthritis and rheumatism·1997

Researchers tested blood samples from 60 ME/CFS patients and found that 83% had unusual antibodies (immune proteins) attacking their own cells—specifically targeting proteins that form the structural framework inside and around cell nuclei. These antibodies were rarely seen in healthy people (only 17%), suggesting this autoimmune pattern might be unique to ME/CFS and could potentially help doctors identify the disease.

E2 ModerateCohortPEM not requiredCase-Control

Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome.

De Lorenzo, F, Hargreaves, J, Kakkar, V V·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·1997

Some ME/CFS patients experience dizziness or fainting when standing up, a condition called orthostatic hypotension. This study tested whether salt supplements could help 22 ME/CFS patients with this symptom. After 8 weeks, salt helped 11 patients feel better, but 10 patients' symptoms returned—and those 10 had lower levels of a hormone called renin that helps regulate blood pressure.

E2 ModerateCohortPEM unclearCross-Sectional

[Prevalence of chronic fatigue syndrome in 4 family practices in Leiden].

Versluis, R G, de Waal, M W, Opmeer, C et al.·Nederlands tijdschrift voor geneeskunde·1997

Researchers in the Netherlands looked at how many people in general medical practices had chronic fatigue syndrome (CFS). They reviewed medical records from about 23,000 patients and found that at least 1-2 out of every 1,000 patients had CFS. Interestingly, they noticed that women were diagnosed with CFS about five times more often than men.

Sleep anomalies in the chronic fatigue syndrome. A comorbidity study.

Fischler, B, Le Bon, O, Hoffmann, G et al.·Neuropsychobiology·1997

This study examined sleep patterns in 49 ME/CFS patients compared to 20 healthy people using overnight sleep monitoring. Patients with ME/CFS had difficulty falling asleep and staying asleep, and spent less time in deep, restorative stage 4 sleep. These sleep problems were distinctive enough that researchers could correctly identify who had ME/CFS based on sleep patterns alone.

Sleep

E2 ModerateCohortPEM not requiredCase-Control

Electron microscopic immunocytological profiles in chronic fatigue syndrome.

Holmes, M J, Diack, D S, Easingwood, R A et al.·Journal of psychiatric research·1997

Researchers used a special microscope to examine immune cells from ME/CFS patients and found structures that resembled a type of virus in 10 out of 17 patients, but not in healthy control subjects. However, when they tried to confirm this finding using additional testing methods, the results were unclear. This suggests something might be different in the cells of some ME/CFS patients, but more research is needed to understand what it means.

E2 ModerateCohortPEM not requiredObservational

Chronic fatigue syndrome.

Mawle, A C·Immunological investigations·1997

This study examined whether ME/CFS might be caused by an infection or involve immune system problems. While researchers didn't find a specific virus or bacteria responsible for the illness, they discovered that when they grouped patients based on whether their symptoms started suddenly or gradually, some differences in immune markers appeared between patients and healthy people.

The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression.

Johnson, S K, Lange, G, DeLuca, J et al.·Applied neuropsychology·1997

Researchers tested whether fatigue directly worsens brain performance on a specific attention test (PASAT) in people with ME/CFS, multiple sclerosis, and depression. They found that people with ME/CFS and depression performed worse overall on the test compared to healthy controls, but fatigue itself did not prevent people from improving with practice. This suggests that fatigue may not be the main factor directly causing the thinking difficulties some ME/CFS patients experience.

Cognitive Impairment

Lack of association of Borna disease virus and human T-cell leukemia virus type 1 infections with psychiatric disorders among Japanese patients.

Kubo, K, Fujiyoshi, T, Yokoyama, M M et al.·Clinical and diagnostic laboratory immunology·1997

Researchers tested whether two viruses—Borna disease virus (BDV) and HTLV-1—might be linked to psychiatric disorders like schizophrenia and depression in Japanese patients. After testing blood samples from 346 patients with psychiatric conditions and 70 healthy people, they found almost no evidence that either virus was associated with these mental health conditions.