Fatigue: Biomedicine, Health & Behavior - Volume 1, Issue 4, 2013

Titles and abstracts for the journal, Fatigue: Biomedicine, Health & Behavior, Volume 1, Issue 4, 2013.

Volume 1, Issue 4, 2013

• A metagenomic approach to investigate the microbial causes of myalgic encephalomyelitis/chronic fatigue syndrome: moving beyond XMRV, An Editorial. Full Text
• Post-exertion malaise in chronic fatigue syndrome: symptoms and gene expression

  Abstract - Background: A primary complaint of chronic fatigue syndrome (CFS) patients is post-exertion malaise, which is a worsening of symptoms following activities such as exercise. Purpose: To examine the link between gene expression for metabolite, adrenergic, immune, and glucocorticoid receptors on leukocytes and symptoms (pain, fatigue, and mood) following a maximal exercise test. Methods: Thirteen CFS patients and 11 healthy participants matched on age and fitness underwent blood draws and completed questionnaires immediately before, and 15 minutes, 48 hours, and 72 hours following, maximal exercise. Symptom and genetic measures collected before and after exercise were compared using a doubly multivariate repeated-measures analysis of variance. Results: This comparison of CFS and healthy participants resulted in a significant multivariate main effect for Group (p < 0.05). Univariate analyses indicated group differences for adrenergic α-2A and glucocorticoid (NR3C1) receptor messenger ribonucleic acid and symptoms of fatigue and confusion. Changes in gene expression were significantly correlated with symptoms. Conclusions: Results suggest that increased glucocorticoid sensitivity may contribute to the symptoms of post-exertion malaise in CFS. As NR3C1 interacts with other transcription factors, investigating the resulting cascades may lead to greater understanding of the biological mechanism of post-exertion malaise. This finding, if confirmed, could lead to novel approaches to prevent symptom exacerbation in CFS.

• Beyond myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptom severity: stress management skills are related to lower illness burden

  Abstract - Background: The onset of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) typically involves reductions in activities of daily living and social interactions (jointly referred to as “illness burden”). Emotional distress has been linked to increased reported symptoms, and stress management skills have been related to lower fatigue severity in CFS patients. Symptom severity and illness burden are highly correlated. The ability to manage stress may attenuate this relationship, allowing individuals to feel less burdened by the illness independent of the severity of their symptoms. Purpose: This study aimed to evaluate if perceived stress management skills affect illness burden via emotional distress, independent of ME/CFS symptom severity. Methods: A total of 117 adults with ME/CFS completed measures of perceived stress management skills, emotional distress, ME/CFS symptom severity, and illness burden. Results: Regression analyses revealed that greater perceived stress management skills related to less social and fatigue-related illness burden, via lower emotional distress. This relationship existed independent of the association of symptom severity on illness burden, and was stronger among those not currently employed. Conclusions: Ability to manage stress is associated with a lower illness burden for individuals with ME/CFS. Future studies should evaluate the efficacy of psychosocial interventions in lowering illness burden by targeting stress management skills.

• The effect of a single bout of exercise on energy and fatigue states: a systematic review and meta-analysis.

  Abstract - Background: Studies examining acute exercise effects on energy and fatigue levels have not been quantitatively summarized. Purpose: To estimate the population effects of a single bout of exercise on energy and fatigue states and examine potential moderators. Methods: Google Scholar and MEDLINE were searched systematically for published studies that measured changes in energy and fatigue after acute exercise. Meta-analytic techniques were used to analyze 58 energy effects and 58 fatigue effects from the same 16 studies involving 678 participants. Most studies involved 21–40 minutes of moderate-intensity aerobic-type exercise. Result: The homogeneous mean effect for energy was Δ = 0.47 (95% confidence interval [CI] = 0.39, 0.56). The heterogeneous mean effect for fatigue was Δ = 0.03 (95% CI = −0.08, 0.13). The fatigue effect was moderated by a three-way interaction between change in feelings of energy, exercise intensity, and exercise duration. Conclusion: Acute exercise enhances feelings of energy. Decreases in fatigue occur only when post-exercise increases in energy are at least moderately large after low-to-moderate intensity exercise lasting longer than 20 minutes. Future research should focus on short-duration (<15 minutes), vigorous-intensity exercise and long-duration (>40 minutes) exercise in non-student groups.

• Scientific and legal challenges to the functional capacity evaluation in chronic fatigue syndrome.

  Abstract - Background: Objective measurements of function often form the basis for legal decisions about whether a patient is fit for return to work, or conversely, entitled to disability compensation. The functional capacity evaluation (FCE) is regarded as the gold standard for measuring work capacity in plaintiffs seeking disability benefits. Yet the FCE often fails to link the unremitting fatigue of chronic fatigue syndrome (CFS) to the ability to work. Purpose: To review the legal rationale and scientific evidence related to functional capacity measurements used to establish disability in individuals with CFS. Methods: Narrative review. Results: Several legal cases demonstrate problems with the FCE as determinative of the ability to work in people with CFS. In addition, scientific studies are lacking to support the reliability and validity of the FCE in this population. The putative metabolic pathology of CFS suggests that maximal cardiopulmonary exercise testing, which combines direct measurements of functioning and metabolic status, may be more appropriate to establish ability and disability than the FCE in this population. Conclusion: Utilization of the FCE in legal cases to establish disability in individuals with CFS may yield erroneous findings that can be addressed with the use of alternative validated measurements.

• Editorial Board, Publishing models and article dates explained. First Page Preview

See also

• Fatigue: Biomedicine, Health & Behavior for other Issues

metabolite A chemical compound produced by, or involved in, metabolism. The term is often used to refer to the degradation products of drugs in the body.

α α / Α. Greek letter alpha or alfa (a symbol used in science), equivalent to "a".

δ δ / Δ. Greek letter delta (a symbol used in science). Equivalent to a "d".

stress Stress can by either physical or psychological, or both. Stress is either 1) a state of emotional or psychological strain or 2) the physical stress (pressure or tension) that a physical object such the human body is placed under, e.g., a stress test is a medical test that monitors the cardiovascular system during strenuous exercise.