Evidence browser

Orthostatic intolerance in adolescent chronic fatigue syndrome.

Stewart, J M, Gewitz, M H, Weldon, A et al.·Pediatrics·1999

This study looked at how the bodies of adolescents with ME/CFS respond when they stand up or tilt upright. Researchers found that nearly all ME/CFS patients showed significant problems with this response, including rapid heart rate, blood pressure drops, and symptoms like dizziness and fainting. These problems were much more common in ME/CFS patients than in healthy teenagers or those with simple fainting disorders.

E2 ModerateBehavioralPEM not requiredCross-Sectional

[Chronic fatigue syndrome:objective criteria of metabolic defects].

Gil'miiarova, F N, Radomskaia, V M, Kretova, I G et al.·Klinicheskaia laboratornaia diagnostika·1999

This study looked at blood protein levels in people who worked at chemical plants in polluted areas and compared them to people living in clean environments. Researchers found that workers in polluted areas had lower levels of protective proteins in their blood and higher levels of waste products, suggesting that exposure to chemical pollution may interfere with the body's natural defense systems and contribute to chronic fatigue.

Chronic fatigue syndrome, chronic fatigue, and psychiatric disorders: predictors of functional status in a national nursing sample.

Wagner-Raphael, Lynne I, Jason, Leonard A, Ferrari, Joseph R·Journal of occupational health psychology·1999

This study looked at nurses with severe tiredness to understand how fatigue affects their daily lives and well-being. Researchers found that as fatigue got worse, people had more trouble with physical activities, work tasks, social interactions, and overall quality of life. Nurses who had ME/CFS experienced greater difficulties than those with fatigue from other causes.

E2 ModerateBehavioralPEM not requiredCross-Sectional

[The chronic fatigue and neurasthenia in the student population].

Mojarro Práxedes MD, Benjumea Pino P·Actas espanolas de psiquiatria·1999

This study looked at fatigue in 277 medical students to see how common chronic fatigue syndrome (CFS) and a related condition called neurasthenia actually are. The researchers found that while over one-third of students reported fatigue, very few met the strict criteria for CFS (less than 1%), and a small number met criteria for neurasthenia (about 3%). The study also found that students with fatigue were more likely to have depression symptoms, though it's unclear whether depression causes fatigue or results from it.

Detection of borna disease virus-reactive antibodies from patients with psychiatric disorders and from horses by electrochemiluminescence immunoassay.

Yamaguchi, K, Sawada, T, Naraki, T et al.·Clinical and diagnostic laboratory immunology·1999

Researchers developed a new blood test to detect antibodies against Borna disease virus (BDV), a virus found in animals. They tested thousands of blood samples from people with various conditions, including psychiatric disorders, and found that people with schizophrenia and mood disorders had higher rates of BDV antibodies compared to healthy blood donors. However, people with chronic fatigue syndrome did not show elevated BDV antibodies in this study.

Cardiovascular response during head-up tilt in chronic fatigue syndrome.

LaManca, J J, Peckerman, A, Walker, J et al.·Clinical physiology (Oxford, England)·1999

This study tested how the hearts of ME/CFS patients respond to positional changes using a tilt table test, where participants lie flat then are gradually tilted upward for 45 minutes. While ME/CFS patients showed different baseline heart rates and heart pumping patterns compared to healthy controls, the overall frequency of fainting-like responses was similar between the two groups.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Psychiatric adjustment in adolescents with a history of chronic fatigue syndrome.

Garralda, E, Rangel, L, Levin, M et al.·Journal of the American Academy of Child and Adolescent Psychiatry·1999

This study looked at mental health in teenagers who had ME/CFS, comparing them to healthy peers. Researchers found that teenagers with a history of ME/CFS were more likely to experience anxiety and depression, had more emotional symptoms, and felt worse about themselves—especially regarding how they fit in socially. Interestingly, those who had recovered from ME/CFS actually showed more anxiety disorders than those still experiencing active illness.

Acute fatigue in chronic fatigue syndrome patients.

Smith, A P, Borysiewicz, L, Pollock, J et al.·Psychological medicine·1999

This study tested whether people with ME/CFS get tired more quickly during mental tasks than healthy people. Researchers compared 67 ME/CFS patients with 126 healthy controls while they performed attention tests over a long session. ME/CFS patients performed worse than healthy people, and the gap widened as fatigue set in, suggesting they struggle more with mental tiredness.

E2 ModerateCohortPEM not requiredCase-Control

Chronic fatigue syndrome and nickel allergy.

Marcusson, J A, Lindh, G, Evengård, B·Contact dermatitis·1999

This study tested 50 patients with ME/CFS and 73 healthy people for allergic reactions to eight different metals. Researchers found that people with ME/CFS were more likely to be allergic to nickel—36% of ME/CFS patients had nickel allergies compared to only 19% of healthy people. This difference was especially pronounced in women with ME/CFS, where over half (52%) showed nickel allergy. The researchers suggest that nickel exposure might somehow trigger or contribute to ME/CFS in some people.

Immune System

E2 ModerateBehavioralPEM not requiredCross-Sectional

Self-reported depression and suicide attempts among U.S. women physicians.

Frank, E, Dingle, A D·The American journal of psychiatry·1999

This study surveyed over 4,500 U.S. women doctors to understand how often they experience depression and attempt suicide. The researchers found that about 1 in 5 women physicians have experienced depression at some point in their lives, and about 1.5% have attempted suicide. Several factors increased the risk, including a history of abuse, substance use, chronic fatigue syndrome, and work-related stress.

E2 ModerateCohortPEM unclearLongitudinal

Prognostic factors for persons with idiopathic chronic fatigue.

Hartz, A J, Kuhn, E M, Bentler, S E et al.·Archives of family medicine·1999

This study followed 199 people with chronic fatigue for 2 years to understand which factors predicted who would improve. Researchers found that people who had clearer thinking, fewer additional symptoms, better sleep patterns, and were married tended to show the most improvement in fatigue. Interestingly, when patients improved in other symptoms like depression, muscle pain, or sleep problems, their fatigue also tended to improve together.

SleepCognitive Impairment

Chronic fatigue syndrome: gender differences in the search for legitimacy.

Clarke, J N·The Australian and New Zealand journal of mental health nursing·1999

This study interviewed 59 people with ME/CFS (18 men and 41 women) about their experiences with the illness and how doctors treated them. While men and women described similar symptoms and the disease itself affected them in comparable ways, they experienced very different treatment from healthcare providers. The study suggests that gender plays an important role in how seriously doctors take ME/CFS patients and how they are believed.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Prediction of peak oxygen uptake in chronic fatigue syndrome.

Mullis, R, Campbell, I T, Wearden, A J et al.·British journal of sports medicine·1999

Researchers tested 130 ME/CFS patients on exercise bikes to measure their peak oxygen uptake (fitness capacity). They found a simple formula could accurately predict oxygen uptake from how hard patients could work during the test, with only a 10.7% average error. Importantly, almost all patients (97%) reported no worsening of symptoms after this maximal exercise test.

Psychological states and neuropsychological performances in chronic Lyme disease.

Elkins, L E, Pollina, D A, Scheffer, S R et al.·Applied neuropsychology·1999

This study looked at mood and thinking abilities in 30 people with post-Lyme syndrome (a condition that can develop after Lyme disease). Researchers found that these patients had lower levels of positive feelings (like happiness or hopefulness) compared to the general population, but their actual thinking and memory skills tested normally. The study suggests that reduced positive mood, rather than depression or other psychiatric conditions, may be the most important psychological marker of this illness.

Brain MRI abnormalities exist in a subset of patients with chronic fatigue syndrome.

Lange, G, DeLuca, J, Maldjian, J A et al.·Journal of the neurological sciences·1999

Researchers used brain MRI scans to look for abnormalities in people with ME/CFS and compared them to healthy controls. They found that some ME/CFS patients—specifically those without a separate psychiatric diagnosis—had small spots of unusual tissue in the white matter of their brains, mostly in the frontal lobes (the front part of the brain). These brain changes were not found in healthy people or in ME/CFS patients who also had psychiatric diagnoses.

E2 ModerateBehavioralPEM not requiredCase-Control

Critical life events, infections, and symptoms during the year preceding chronic fatigue syndrome (CFS): an examination of CFS patients and subjects with a nonspecific life crisis.

Theorell, T, Blomkvist, V, Lindh, G et al.·Psychosomatic medicine·1999

This study looked at whether stressful life events and infections in the months before ME/CFS develops might play a role in triggering the illness. Researchers interviewed 46 people with ME/CFS and 46 matched control subjects without the illness, asking them to recall what happened and how they felt month-by-month for a year. They found that people who developed ME/CFS experienced more infections and stressful events—especially in the 3 months right before onset—and their fatigue, pain, and fever symptoms stayed very high even after diagnosis, unlike the control group who recovered.

E2 ModerateCohortPEM unclearCase-Control

Changes in immune parameters seen in Gulf War veterans but not in civilians with chronic fatigue syndrome.

Zhang, Q, Zhou, X D, Denny, T et al.·Clinical and diagnostic laboratory immunology·1999

This study compared immune system markers in people with ME/CFS, looking separately at Gulf War veterans and non-veterans. Researchers found that Gulf War veterans with ME/CFS had different immune patterns (more of certain types of T cells, fewer NK cells, and higher levels of inflammation markers) compared to healthy veterans. However, non-veterans with ME/CFS showed no such immune differences from healthy controls, suggesting Gulf War service may have affected the immune system differently than sporadic ME/CFS.

Immune System

Autonomic function in patients with chronic fatigue syndrome.

Soetekouw, P M, Lenders, J W, Bleijenberg, G et al.·Clinical autonomic research : official journal of the Clinical Autonomic Research Society·1999

Researchers tested whether ME/CFS patients have problems with the part of the nervous system that automatically controls heart rate and blood pressure. They compared 37 ME/CFS patients to 38 healthy people using several tests (like standing up quickly, holding their breath, and doing mental math). The study found only minor differences, suggesting that major autonomic problems may not be the primary issue in ME/CFS, though some specific responses to stress were reduced.

Orthostatic intolerance in the chronic fatigue syndrome.

Schondorf, R, Benoit, J, Wein, T et al.·Journal of the autonomic nervous system·1999

This study looked at whether ME/CFS patients experience problems with blood pressure and heart rate when standing up quickly, a condition called orthostatic intolerance. Researchers tested 75 ME/CFS patients and 48 healthy controls using a tilt table test and other physical challenges. They found that 40% of ME/CFS patients had orthostatic intolerance compared to fewer healthy controls, suggesting this may be an important symptom in some patients that could be treated.

Patterns of orthostatic intolerance: the orthostatic tachycardia syndrome and adolescent chronic fatigue.

Stewart, J M, Gewitz, M H, Weldon, A et al.·The Journal of pediatrics·1999

This study looked at how the hearts and blood pressure of adolescents with ME/CFS and a related condition called orthostatic tachycardia syndrome (OTS) respond when they stand up or are tilted upright. Researchers found that adolescents with ME/CFS had more severe problems with standing (like dizziness and fainting) than those with OTS, but the underlying patterns were quite similar. The study suggests that OTS may be a milder version of the same blood pressure and heart rate problems seen in ME/CFS.