Prolonged Fatigue Research Articles

Effect of Prolonged Running-induced Fatigue on Free-torque Components

Running is a popular sport because it demands physical activity and can be performed at a convenient time in any place (Ida et al., 2010). Although running has a positive effect on health, it can have a negative impact on the body because of possible injury. In particular, the incidence of injury from prolonged running is reported to be 30~ 79% (Lun et al., 2004; Taunton et al., 2003; van Gent et al., 2007). There are various possible factors involved in injury from prolonged running, including mechanical abnor- malities previous injuries sex, body mass index, training frequency, intensity, and duration, muscle strength, flexibility, shoes, and fatigue (Taunton et al., 2003). Among prolonged running injuries, stress fractures are a common problem and account for a large proportion of running injuries (Taunton et al., 2002). In prolonged running, stress fractures of the tibia are most common, accounting for 35~56% of the stress fractures caused by prolonged running (Romani et al., 2002). One of the bio- mechanical factors causing tibial stress fractures is free torque (FT) (Milner & Davis, 2006). FT refers to the torque in the vertical axis that is generated by friction between the foot and the ground during the support phase in

The Association between Job-Related Psychosocial Factors and Prolonged Fatigue among Industrial Employees in Taiwan.

Background and ObjectivesProlonged fatigue is common among employees, but the relationship between prolonged fatigue and job-related psychosocial factors is seldom studied. This study aimed (1) to assess the individual relations of physical condition, psychological condition, and job-related psychosocial factors to prolonged fatigue among employees, and (2) to clarify the associations between job-related psychosocial factors and prolonged fatigue using hierarchical regression when demographic characteristics, physical condition, and psychological condition were controlled.MethodsA cross-sectional study was employed. A questionnaire was used to obtain information pertaining to demographic characteristics, physical condition (perceived physical health and exercise routine), psychological condition (perceived mental health and psychological distress), job-related psychosocial factors (job demand, job control, and workplace social support), and prolonged fatigue.ResultsA total of 3,109 employees were recruited. Using multiple regression with controlled demographic characteristics, psychological condition explained 52.0% of the variance in prolonged fatigue. Physical condition and job-related psychosocial factors had an adjusted R2 of 0.370 and 0.251, respectively. Hierarchical multiple regression revealed that, among job-related psychosocial factors, job demand and job control showed significant associations with fatigue.ConclusionOur findings highlight the role of job demand and job control, in addition to the role of perceived physical health, perceived mental health, and psychological distress, in workers’ prolonged fatigue. However, more research is required to verify the causation among all the variables.

Cyclic deformation behaviors of a high strength carbide-free bainitic steel

The cyclic deformation behaviors of low-temperature bainite, lower bainite and upper bainite obtained on a high-strength carbide-free bainitic steel were examined through low-cycle fatigue testing. The relationship between the bainitic microstructure and fatigue behavior was systematically studied using scanning electron microscopy, transmission electron microscopy, atom probe technology, and electron back-scattered diffraction analyses. The results show that low-cycle fatigue undergoes three stages, namely, cyclic hardening, saturation or cyclic softening, and fracturing. The low-temperature bainite exhibits a long fatigue life under the total strain amplitudes, because of its high strength and larger high-angle misorientation distribution of the packets of bainitic ferrite plates. The low-temperature bainite also presents bilinearity in the Coffin–Manson plots. Coordinate deformation and high-uniform elongation lead to prolonged fatigue life at low plastic strain amplitude, whereas phase component primarily affects the fatigue life at high plastic strain amplitude. Highly stable film-like retained austenite is beneficial to arresting fatigue crack propagation. Blocky type retained austenite easily transforms to martensite, resulting in high compatible deformation capability. The hardening ability of the low-temperature bainite is higher than that of the upper bainite, which is attributed to its high pre-existent density of dislocations transformed from movable to immovable during initial hardening stage.

Validation of the Korean Version of Schedule of Fatigue and Anergia: General Physician Questionnaire.

The Schedule of Fatigue and Anergy/General Physician (SOFA/GP) was developed to screen for prolonged fatigue in the primary care setting. We aimed to evaluate the reliability and validity of the Korean version of the SOFA/GP (SOFA/GP-K), which is adapted from the original English version. We performed translation and back translation, and after conducting a pilot study, we tested the final version of the questionnaire for its reliability and validity in a Korean primary care setting. Two hundred participants that visited a health examination center in a university hospital completed the survey between September and November 2012. A second survey was performed within 2 weeks of the primary survey to test for reliability. We evaluated concurrent validity between the SOFA/GP-K score, the Fatigue Severity Scale (FSS), and Brief Fatigue Index (BFI) scores. The Spearman correlation coefficient between SOFA/GP-K and FSS was 0.71 and 0.61 between SOFA/GP-K and BFI. Internal consistency of SOFA/GP-K was observed (Cronbach's alpha = 0.82) and construct validity was confirmed by factor analysis. The Kappa scores for test-retest reliability for each survey item were between 0.28 and 0.64. The SOFA/GP-K is a valid and reliable questionnaire for screening fatigue in a primary care setting.

Fatigue properties of Fe-28Mn-6Si-5Cr-0.5NbC alloy

In this study, we conducted a low-cycle fatigue testing in a Fe-28Mn-6Si-5Cr-0.5NbC (FMS) alloy and a SUS304 steel. The fatigue tests were made using a servo hydraulic fatigue testing machine of capacity 50kN, at maximum total strain amplitudes (εta) of 2.0%, 1.4%, 0.9%, 0.6%. In the SUS304 steel, with decrease in applied strain amplitude, stress-strain hysteresis loop is reduced. On the other hand, the stress response of the FMS alloy is almost unchanged, irrespective of the applied strain amplitude. The life to failure of the FMS alloy is 4 times higher at εta=0.6%, and twice at εta=0.9% and at εta=1.4% than the SUS304 steel. In addition, the stress amplitude of the FMS alloy is 2 times higher at εta =0.6 %, and 1.5 times higher at εta =0.6% than the SUS304 steel. The prolonged fatigue life of the FMS alloy is attributable to the reversible deformation associated with the transformation pseudo-elasticity that can reduce the accumulated strain.

Work, eat and sleep: towards a healthy ageing at work program offshore

BackgroundHealth management tools need to be developed to foster healthy ageing at work and sustain employability of ageing work-forces. The objectives of this study were to 1) perform a needs assessment to identify the needs of offshore workers in the Dutch Continental Shelf with regard to healthy ageing at work and 2) to define suitable program objectives for a future healthy ageing at work program in the offshore working population.MethodsA mixed methods design was used applying an intervention mapping procedure. Qualitative data were gathered in N = 19 semi-structured interviews and six focus-group sessions (N = 49). Qualitative data were used to develop a questionnaire, which was administered among N = 450 offshore workers. Subgroup analyses were performed to investigate age-related differences relating to health status and work-related factors.ResultsThe importance of good working environments, food, as well as sleep/fatigue management was identified by the qualitative data analysis. A total of 260 offshore workers completed the questionnaire. Significant differences in work ability were found between offshore workers aged <45 and 45–54 years (mean 8.63 vs. 8.19; p = 0.005) and offshore workers aged <45 and >55 years (mean 8.63 vs. 8.22; p = 0.028). Offshore workers had a high BMI (M = 27.06, SD = 3.67), with 46 % classified as overweight (BMI 25–30) and 21 % classified as obese (BMI >30). A significant difference in BMI was found between offshore workers aged <45 and ≥55 years (mean 26.3 vs. 28.6; p <0.001). In total, 73 % of offshore workers reported prolonged fatigue. A significant difference in fatigue scores was found between offshore workers aged <45 and ≥55 years (mean 36.0 vs. 37.6; p = 0.024). Further, a “dip” was reported by 41 % of offshore workers. Dips were mainly experienced at day 10 or 11 (60 %), with 45 % experiencing the dip both as physical and mental fatigue, whereas 39 % experienced the dip as only mental fatigue.ConclusionsBoth qualitative and quantitative analyses identified work, food and sleep/fatigue management as most important program objectives for a healthy ageing at work and sustainable employability program offshore. Future studies should investigate possible causes of dip occurrences and high fatigue scores to identify suitable interventions.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-016-2807-5) contains supplementary material, which is available to authorized users.

Constructing better roads with asphalt rubber

Abstract Brazilians mixtures containing asphalt rubber were evaluated by mechanical laboratory tests. A conventional mixture with asphalt CAP-50/70 was produced as a mixture control. With the aim of compare the Brazilians mixtures performance, a Portuguese asphalt rubber mixture was tested as well. The testing set involved the determination of the mechanical properties, fatigue and permanent deformation, of asphalt rubber produced by wet process through two different systems: continuous blend and terminal blend. The asphalt rubber morphology was evaluated in order to determine the compatibility of the systems. The asphalt rubber mixtures exhibit good resistance to permanent deformation and prolonged fatigue life in relation to mixture control. Therefore it is concluded that the application of asphalt rubber alters the characteristics of asphalt mixture in a very beneficial way.

Monoclonal Gammopathy in the General Practioners’s Office. Diagnosis and Treatment of Plasma Cell Myeloma

A monoclonal gammopathy is a common finding in the general practitioner’s office. An active search for a paraproteinemia is indicated in case of suspected malignancy, evidence of end organ damage (e.g. anemia, renal insufficiency) or in case of recurrent infections or prolonged fatigue. Plasma cell myeloma is an important differential diagnosis of a monoclonal gammopathy and implies a broad spectrum of diagnostic as well as therapeutic consequences for the patient. Plasma cell myeloma is still being considered an incurable disease, but its prognosis could be significantly improved with the introduction of new drugs.

Effect of thermal aging on the low cycle fatigue behavior of Z3CN20.09M cast duplex stainless steel

Nuclear grade Z3CN20.09M cast duplex stainless steel exhibits enhanced cyclic stress response and prolonged low cycle fatigue life at room temperature after thermal aging at 400°C for up to 6000h. The threshold strain amplitude for the onset of secondary hardening is shifted to a lower value after thermal aging. Microstructural observations reveal that fatigue cracks tend to initiate from phase boundaries in virgin specimens, but to initiate in the ferrite phase in aged ones. Denser fatigue striations are found on the fracture surface of fatigued specimen subjected to longer thermal aging duration. These observations are explained in the context of thermal aging induced embrittlement of the ferrite phase and deformation induced martensitic phase transformation in the austenite phase.

The Role of Toll-Like Receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis: A New Promising Therapeutic Approach?

Perturbations in immune processes play an important role in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME), a multifactorial disorder mainly characterized by severe and prolonged fatigue and tipically affecting a variety of bodily systems including the immune system. Recent reports have shown that CFS/ME is an inflammatory disorder may be associated with autoimmune responses, mainly characterized by reduced functional activity of most immune cells, including neutrophils, natural killer cells, monocytes/macrophage and dendritic cells, together with dysregulations in cytokine levels, responsible for changes in the adaptive immune system. Interactions between gut microorganisms and host immune function have been shown to contribute to aberrant inflammation in CFS/ME patients. Commensal and/or pathogen-associated molecular patterns detected by Toll-like receptors (TLRs) expressed on intestinal epithelial cells appear to trigger inflammatory signaling cascade leading to neuroinflammation and neurodegeneration. This paper examines the role of TLR-mediated innate immunity in CFS/ME with evaluation of the current literature, also discussing about innovative therapeutic approaches represented by immunomodulators TLR-targeting.

Fatigue prolongée ou chronique d’origine indéterminée

Although prolonged or chronic fatigue is a very common complaint in primary care medicine, a biomedical obvious cause is often not found. In such a case, for women between 18 and 50 years with a ferritin level of less than 50 µg/l in the absence of anaemia, an iron supplementation may be associated with an improvement in fatigue. Appropriate treatment is also important for depression, anxiety or insomnia. In other cases, the approach is essentially non-pharmacological in the form of lifestyle advice, empathy and cognitive behavioural therapy as well as progressive and adapted physical exercises.

The effect of osteoporosis treatments on fatigue properties of cortical bone tissue

Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFFs). AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene), a bisphosphonate (alendronate or zoledronate), or parathyroid hormone (teriparatide, PTH). Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissue treated with alendronate had reduced fatigue life and less modulus loss at failure compared with other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared with alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

Prolonged fatigue in Ukraine and the United States: prevalence and risk factors

Background: Prolonged, severe, unalleviated fatigue may be disabling whether it occurs on its own or in conjunction with medical or psychiatric conditions. This paper compares the prevalence and correlates of prolonged fatigue in general population samples in Ukraine versus the US. Methods: Population surveys were conducted in 2002 in both Ukraine (Ukraine World Mental Health [WMH] Survey) and the US (National Comorbidity Survey-Replication; NCS-R). Both surveys administered the Composite International Diagnostic Interview (CIDI 3.0), which contained modules assessing: neurasthenia (prolonged fatigue); mood, anxiety, and alcohol/drug use disorders; chronic medical conditions; and demographic characteristics. Multivariable logistic regression was used to examine risk factors in each country. Results: The lifetime prevalence of prolonged fatigue was higher in Ukraine (5.2%) than the US (3.7%). In both countries, one-fifth of individuals with prolonged fatigue had no medical or DSM-IV psychiatric condition. Also in both settings, fatigue was significantly associated with socio-demographic characteristics (being female, not working, and married before) as well as early onset and adult episodes of mood/anxiety disorder. Fatigue prevalence in Ukraine increased with age, but decreased in the US at age 70. Unique risk factors for fatigue in Ukraine included lower socio-economic status, Ukrainian versus Russian ethnicity, and cardiovascular disease. Unique risk factors in the US were parental depression/anxiety, adult episodes of alcohol/drugs, pain conditions, and other health problems. Conclusions: The lifetime prevalence of prolonged fatigue in Ukraine was 40% higher than that found in US data. In addition, fatigue prevalence increased sharply with age in Ukraine perhaps due to limited social and medical resources and greater comorbidity.

Does oral coenzyme Q10 plus NADH supplementation improve fatigue and biochemical parameters in chronic fatigue syndrome?

Chronic fatigue syndrome (CFS) is a chronic and extremely debilitating illness characterized by prolonged fatigue and multiple symptoms with unknown cause, diagnostic test, or universally effective treatment. Inflammation, oxidative stress, mitochondrial dysfunction, and CoQ10 deficiency have been well documented in CFS. We conducted an 8-week, randomized, double-blind placebo-controlled trial to evaluate the benefits of oral CoQ10 (200 mg/day) plus NADH (20 mg/day) supplementation on fatigue and biochemical parameters in 73 Spanish CFS patients. This study was registered in ClinicalTrials.gov (NCT02063126). A significant improvement of fatigue showing a reduction in fatigue impact scale total score (p<0.05) was reported in treated group versus placebo. In addition, a recovery of the biochemical parameters was also reported. NAD+/NADH (p<0.001), CoQ10 (p<0.05), ATP (p<0.05), and citrate synthase (p<0.05) were significantly higher, and lipoperoxides (p<0.05) were significantly lower in blood mononuclear cells of the treated group. These observations lead to the hypothesis that the oral CoQ10 plus NADH supplementation could confer potential therapeutic benefits on fatigue and biochemical parameters in CFS. Larger sample trials are warranted to confirm these findings.

P3-10-2 - Treatment After Discontuance of Regorafenib for Colorectal Cancer

Background: Regorafenib has statically proved effect for the third line therapy of metastatic colorectal cancer, however there seemed to be some problems in clinical practice because of shortage of clinical experience .Patients: Nine cases of metastatic colorectal cancer, who has terminated administration of Regorafenib, by reason for progression of disease in six patients and severe fatigue in three. There were three cases on third line, two cases on fourth line, three cases on fifth or later line.Results: Capecitabine plus Bevasizumab was administered in five cases, S-1 plus CPT-11 was administered in one. Three cases who complained of severe fatigue after termination of Regorafenib administration did not receive another chemotherapy for cancer.Conclusion: There was no evidence for the anti-cancer-treatment after Regorafenib administration as yet. However there are some patients who can stand more lines of chemotherapy. Prolonged fatigue is a clinical problem to be overcome for further treatment which should be proved of its clinical meaning in near future.

The response of the pulmonary circulation and right ventricle to exercise: exercise-induced right ventricular dysfunction and structural remodeling in endurance athletes (2013 Grover Conference series).

There is unequivocal evidence that exercise results in considerable health benefits. These are the result of positive hormonal, metabolic, neuronal, and structural changes brought about by the intermittent physiological challenge of exercise. However, there is evolving evidence that intense exercise may place disproportionate physiological stress on the right ventricle (RV) and the pulmonary circulation. Both echocardiographic and invasive studies are consistent in demonstrating that pulmonary arterial pressures increase progressively with exercise intensity, such that the harder one exercises, the greater the load on the RV. This disproportionate load can result in fatigue or damage of the RV if the intensity and duration of exercise is sufficiently prolonged. This is distinctly different from the load imposed by exercise on the left ventricle (LV), which is moderated by a greater capacity for reductions in systemic afterload. Finally, given the increasing RV demand during exercise, it may be hypothesized that chronic exercise-induced cardiac remodeling (the so-called athlete's heart) may also disproportionately affect the RV. Indeed, there is evidence, although somewhat inconsistent, that RV volume increases may be relatively greater than those for the LV. Perhaps more importantly, there is a suggestion that chronic endurance exercise may cause electrical remodeling, predisposing some athletes to serious arrhythmias originating from the RV. Thus, a relatively consistent picture is emerging of acute stress, prolonged fatigue, and long-term remodeling, which all disproportionately affect the RV. Thus, we contend that the RV should be considered a potential Achilles' heel of the exercising heart.

Evaluation of prolonged fatigue post-West Nile virus infection and association of fatigue with elevated antiviral and proinflammatory cytokines.

This study aimed to characterize fatigue postinfection among study participants with a history of West Nile virus (WNV) infection and determine whether antiviral and pro-inflammatory cytokines were significantly elevated in those reporting prolonged fatigue. We found that 31% (44/140) of study participants experienced prolonged (more than 6 months) fatigue postinfection, with an average length of fatigue duration of 5 years. Females, those younger than 50 years of age, and those with symptomatic clinical WNV disease were significantly more likely to report fatigue. Pro-inflammatory and antiviral cytokines (granulocyte macrophage colony stimulating factor, interferon-γ, interferon-γ inducing protein 10, interleukin 2, interleukin 6, and interleukin 12p70) were significantly elevated in those reporting fatigue postinfection compared to those not reporting fatigue. Clinicians should consider history of WNV infection as a possible factor when evaluating causes of prolonged fatigue following a febrile viral illness in their patients.

Induction of interleukin-1β by activated microglia is a prerequisite for immunologically induced fatigue.

We previously reported that an intraperitoneal (i.p.) injection of synthetic double-stranded RNA, polyriboinosinic:polyribocytidylic acid (poly-I:C), produced prolonged fatigue in rats, which might serve as a model for chronic fatigue syndrome. The poly-I:C-induced fatigue was associated with serotonin transporter (5-HTT) overexpression in the prefrontal cortex (PFC), a brain region that has been suggested to be critical for fatigue sensation. In the present study, we demonstrated that microglial activation in the PFC was important for poly-I:C-induced fatigue in rats, as pretreatment with minocycline, an inhibitor of microglial activation, prevented the decrease in running wheel activity. Poly-I:C injection increased the microglial interleukin (IL)-1β expression in the PFC. An intracerebroventricular (i.c.v.) injection of IL-1β neutralising antibody limited the poly-I:C-induced decrease in activity, whereas IL-1β (i.c.v.) reduced the activity in a dose-dependent manner. 5-HTT expression was enhanced by IL-1β in primary cultured astrocytes but not in microglia. Poly-I:C injection (i.p.) caused an increase in 5-HTT expression in astrocytes in the PFC of the rat, which was inhibited by pretreatment with minocycline (i.p.) and rat recombinant IL-1 receptor antagonist (i.c.v.). Poly-I:C injection (i.p.) led to a breakdown of the blood-brain barrier and enhanced Toll-like receptor 3 signaling in the brain. Furthermore, direct application of poly-I:C enhanced IL-1β expression in primary microglia. We therefore propose that poly-I:C-induced microglial activation, which may be at least partly caused by a direct action of poly-I:C, enhances IL-1β expression. Then, IL-1β induces 5-HTT expression in astrocytes, resulting in the immunologically induced fatigue.

Prevalence and clinical specificity of fatigue symptoms in chronic fatigue syndrome, multiple sclerosis, and myasthenia gravis

This article provides a critical review of the psychological and related literature on fatigue resulting in both mental and physical experiences. On one hand, prolonged severe fatigue is a prominent disabling symptom in various diseases of different aetiology – psychiatric (e.g. depression), somatic (e.g. some infections) and neurologic (e.g. multiple sclerosis, myasthenia gravis). For instance, fatigue is a main symptom of myasthenia that leads to pathological skeletal muscle weakness. Furthermore, 40 to 90 per cent of individuals suffering from multiple sclerosis confirm they have experienced fatigue, which impairs their cognitive functioning. In both multiple sclerosis and myasthenia, fatigue has not only a physical but also a psychological dimension. On the other hand, fatigue can be seen as an isolated set of symptoms of unknown origin called the chronic fatigue syndrome (CFS). The development of the concept, diagnostic criteria and some strategies of coping with CFS are presented. Various somatic disorders, as well as subjective cognitive and emotional complaints, are common and well documented in patients with CFS. The most typical include depression, as well as problems with concentration of attention, decision-making and reasoning in complex situations. However, general intellectual abilities and higher order cognitive skills are intact. Directions for future research are outlined.

Leisure Opportunities and Fatigue in Employees: A Large Cross-Sectional Study

The aim of the present study was to investigate the association between perceived leisure availability and fatigue in working individuals and the extent it mediates the known association between work hours and fatigue. A sample of 7,154 working individuals (ages 20–59) was drawn from the Austrian Health Survey 2006–07. The associations were determined using stepwise logistic regression analysis. Individuals perceiving few opportunities for leisure activities had a 2.7 greater likelihood of having prolonged fatigue (95% CI = 2.05–3.29) than those with sufficient leisure, after controlling for relevant confounders. Furthermore, the positive association between weekly hours of work and fatigue was mediated to a greater part by leisure opportunities, indicating that working long hours leads to fatigue by limiting leisure opportunities. The results of this study suggest that the perceived availability of leisure is a source of health and well-being in working individuals.