Fatigue: Biomedicine, Health & Behavior - Volume 7, Issue 2, 2019

Titles and abstracts for the journal, Fatigue: Biomedicine, Health & Behavior, Volume 7, Issue 2, 2019.

Volume 7, Issue 2, 2019

 * Myalgic encephalomyelitis and chronic fatigue syndrome case definitions: effects of requiring a substantial reduction in functioning"Abstract - Background: Current case definitions for myalgic encephalomyelitis (ME) and chronic fatigue syndrome (CFS) require an individual to report a ‘substantial reduction’ in activity levels, when compared to premorbid functioning. However, little guidance is provided on how to measure these reductions, as well as what level of reduction should be deemed ‘substantial,’ leading to inconsistencies in how this criterion is applied across research settings. Purpose: The current study examined the influence of substantial reduction criterion on case definitions. Method: The current study analyzed an international convenience sample of 1002 individuals with ME or CFS, 53 healthy controls, and 260 controls with other chronic illnesses. Results: Findings indicated that the utility of the substantial reduction criterion varied by case definition, with more stringent case definitions not needing this criterion to identify cases. Conclusion: These results suggest that the requirement of a substantial reduction in functioning may be redundant when case definitions specify that individuals must endorse a set of core symptoms at specified frequency and severity levels."
 * Serum histidine is lower in fatigued women with multiple sclerosis"Abstract - Background: Disabling persistent perceived fatigue occurs in 50% of people with multiple sclerosis (MS), but mechanisms are poorly understood. Low histidine could contribute to fatigue since it is the neurotransmitter histamine precursor and low serum levels are reported in other diseases where fatigue is common (e.g. breast cancer, kidney disease, diabetes). Serum histidine is also inversely correlated with proinflammatory cytokines (e.g. TNF, IFN-y), which have been linked to MS fatigue. Purpose: To determine if serum histidine is low in fatigued women with MS, and if histidine is related to differences in proinflammatory cytokines. Methods: Participants were classified as having elevated (n = 19) or normal (n = 18) perceived fatigue based on a median sample split using Profile of Mood States fatigue scale scores, with the elevated fatigue group having scores >7. Histidine and gene-expression of TNF, IFN-y, and leptin were assayed from a serum sample. Results: After adjustment for depression, serum histidine was significantly lower in women with MS with elevated fatigue, compared to normal fatigue (64.57 vs. 70.48 nmol/mL, p = .048, g = 0.75). There were no differences between groups in cytokine expression (all p > .24). Gene expression of TNF correlated with histidine only in people with normal fatigue (r = .51, p = .034), while no other cytokines related to histidine levels. Conclusions: These results provide evidence that serum histidine is lower in fatigued women with MS, but the study did not find a relationship between histidine and TNF, IFN-y, or leptin gene expression."
 * Deciphering fatigue factor in chronic hepatitis B infection"Abstract - Background: With success in treating hepatitis C disease, chronic hepatitis B infection will be given more attention here forward. Whereas prevention of late morbidity with chronic hepatitis B infection is an admirable goal, the benefit for treating chronic carriers who lack determinable advances in their liver disease remains a debate. Purpose: Fatigue, as a symptom, is one of several clinical complications that may be useful to assess the treatment of relatively asymptomatic chronic carriers. This narrative review assesses the current status for assessment of fatigue in this context. Methods: A literature review was conducted of citations intersecting fatigue and hepatitis B as found in PubMed, EMBASE, CINAHL Plus, and the Cochrane Library. Results: Fatigue measurement can be direct or indirect with the assistance of several survey instruments, but there is a lack of universal adoption of any one or more. Nevertheless, there appears to be a consensus that worse fatigue scores are associated with increased hepatitis B-associated morbidity. There is no clear consensus about which quality of life indicators will serve treatment studies best. Conclusion: Studies of treatment that assess fatigue and other clinical symptoms as outcomes must be properly matched and controlled. The combination of clinical and/or biochemical measures should have uniformity and consensus among scientists."
 * The relation between fatigue severity and anxious arousal, negative affect, and emotion dysregulation among adult e-cigarette users "Abstract - Background: Electronic cigarette (e-cigarette) use has risen dramatically in the United States. Research on combustible cigarette use has indicated that mental health symptoms and disorders are among the most important factors related to the maintenance and relapse of use. There is emerging research that suggests mental health symptoms, such as anxiety and negative affect, are overrepresented among e-cigarette users and that these factors are related to more frequent use of e-cigarettes. Yet, little is known about individual difference factors that may be associated with some of the most common mental health symptoms among e-cigarette users. Objective: Clinically significant fatigue may be one individual difference factor related to greater anxiety and distress and dysregulated emotional states more generally among e-cigarette users. Unfortunately, past work has yet to explore this relation. Method: Thus, the current study sought to evaluate clinically significant fatigue severity and its relation to negative affect, anxious arousal, and emotion dysregulation among 525 adult e-cigarette smokers (50.9% female, Mage = 35.25 years, SD = 10.10). Results: Results indicated that severe fatigue was significantly related to negative affect (p < 0.001), anxious arousal (p < 0.001), and emotion dysregulation (p < 0.001); effects that were evident after adjusting for a range of other factors (e.g. combustible cigarette use). Conclusions: These novel empirical results highlight the severity of fatigue as a potentially important construct in efforts to better understand common mental health problems among e-cigarette users."
 * Acceptance, fatigue severity and self-reported physical activity in individuals with chronic fatigue syndrome/myalgic encephalomyelitis "Abstract - Background: Acceptance is a coping strategy associated with chronic pain management, but its effectiveness is unclear for Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME). Objective: The aim of the study was to investigate the relationship between acceptance, fatigue severity, pain and self-reported physical activity in individuals with CFS/ME. Method: Ten females and seven males diagnosed with CFS/ME (51.9 ± 8.8 years), and gender, age-matched sedentary controls, completed self-reported measures of acceptance, fatigue severity and physical activity. Acceptance was measured using the Chronic Pain Acceptance Questionnaire and Acceptance and Action Questionnaire-II. Fatigue was assessed with the Fatigue Severity Scale, and Physical Activity using the International Physical Activity Questionnaire – Short Form. Self-reported physical activity was calculated using categorical and continuous measures (MET-minutes). Result: CFS/ME and control groups were compared using Independent t-tests and Spearman's Rho correlations. The CFS/ME group reported significantly greater fatigue severity and psychological inflexibility, and lower pain willingness and time spent sitting than controls. However, no between-group differences for activity engagement or physical activity. The CFS/ME group showed a negative relationship between pain willingness and psychological inflexibility, and a positive relationship between walking time and the time since symptom onset, and time since diagnosis. Conclusion: Despite reporting greater fatigue and less acceptance of their illness, CFS/ME patients had comparable levels of physical activity to controls, possibly due to pacing their activity to avoid symptom exacerbation. CFS/ME patients with an older diagnosis walked further than the newly diagnosed, suggesting the development of better coping skills and management strategies over time."