Tired, weak, or in need of rest: fatigue among general practice attenders

Psychosocial and Clinical Associations of Fatigue Severity and Fatigue-Related Impairment in Kidney Transplant Recipients

Debilitating fatigue is common in people living with kidney disease and often persists after a kidney transplant. Current understanding of fatigue is centered around pathophysiological processes. Little is known about the role of cognitive and behavioral factors. The aim of this study was to evaluate the contribution of these factors to fatigue among kidney transplant recipients (KTRs). A cross-sectional study of 174 adult KTRs who completed online measures of fatigue, distress, illness perceptions, and cognitive and behavioral responses to fatigue. Sociodemographic and illness-related information was also collected. 63.2% of KTRs experienced clinically significant fatigue. Sociodemographic and clinical factors explained 16.1% and 31.2% of the variance in the fatigue severity and fatigue impairment, respectively, increasing by 28% and 26.8% after adding distress. In adjusted models, all the cognitive and behavioral factors except for illness perceptions were positively associated with increased fatigue-related impairment, but not severity. Embarrassment avoidance emerged as a key cognition. In conclusion, fatigue is common following kidney transplantation and associated with distress and cognitive and behavioral responses to symptoms, particularly embarrassment avoidance. Given the commonality and impact of fatigue in KTRs, treatment is a clinical need. Psychological interventions targeting distress and specific beliefs and behaviors related to fatigue may be beneficial.

Fatigue and physical activity levels in poles living in Poland and the United Kingdom in the further year of the COVID-19 pandemic: a pilot study

OBJECTIVES

The aim of this study was to conduct a preliminary assessment of the prevalence of fatigue and level of physical activity, as well as the relationship between fatigue and physical activity among Poles living in Poland and the United Kingdom (UK) in the further year in the COVID-19 pandemic.

METHODS

A web-based online survey was conducted among Poles living permanently in Poland and the UK in January 2023. Responses were obtained from 200 respondents aged 18-69 years. The level of fatigue was assessed by the Modified Fatigue Impact Scale (MFIS). The level of physical activity was measured by the International Physical Activity Questionnaire (IPAQ).

RESULTS

The median for the total fatigue score was equal to 17 points out of a possible 105. 13.5% of the subjects had a low level of physical activity, the average MET for high-intensity activity was 1294.55 METs, for moderate activity 714.44 METs, and for walking 631 METs. As age and number of COVID-19 cases increased, scores on the MFIS questionnaire scale also increased. With an increase in the number of COVID-19 cases, high-intensity MET scores decreased.

CONCLUSIONS

The level of fatigue, in contrast to the level of physical activity, was low in the study population. There were few statistically significant differences in fatigue between people living in Poland and the UK. Further experimental studies on the physiological mechanism of differences in fatigue and physical activity are needed.

Psychological factors and brain magnetic resonance imaging metrics associated with fatigue in persons with multiple sclerosis

BACKGROUND

Besides demographics and clinical factors, psychological variables and brain-tissue changes have been associated with fatigue in persons with multiple sclerosis (pwMS). Identifying predictors of fatigue could help to improve therapeutic approaches for pwMS. Therefore, we investigated predictors of fatigue using a multifactorial approach.

METHODS

136 pwMS and 49 normal controls (NC) underwent clinical, neuropsychological, and magnetic resonance imaging examinations. We assessed fatigue using the "Fatigue Scale for Motor and Cognitive Functions", yielding a total, motor, and cognitive fatigue score. We further analyzed global and subcortical brain volumes, white matter lesions and microstructural changes (examining fractional anisotropy; FA) along the cortico striatal thalamo cortical (CSTC) loop. Potential demographic, clinical, psychological, and magnetic resonance imaging predictors of total, motor, and cognitive fatigue were explored using multifactorial linear regression models.

RESULTS

53% of pwMS and 20% of NC demonstrated fatigue. Besides demographics and clinical data, total fatigue in pwMS was predicted by higher levels of depression and reduced microstructural tissue integrity in the CSTC loop (adjusted R2 = 0.52, p < 0.001). More specifically, motor fatigue was predicted by lower education, female sex, higher physical disability, higher levels of depression, and self-efficacy (adjusted R2 = 0.54, p < 0.001). Cognitive fatigue was also predicted by higher levels of depression and lower self-efficacy, but in addition by FA reductions in the CSTC loop (adjusted R2 = 0.45, p < 0.001).

CONCLUSIONS

Our results indicate that depression and self-efficacy strongly predict fatigue in MS. Incremental variance in total and cognitive fatigue was explained by microstructural changes along the CSTC loop, beyond demographics, clinical, and psychological variables.

Post-COVID-19 fatigue and health-related quality of life in Saudi Arabia: a population-based study

Background

Despite substantial literature on symptoms and long-term health implications associated with COVID-19; prevalence and determinants of post-acute COVID-19 fatigue (PCF) remain largely elusive and understudied, with scant research documenting health-related quality of life (HRQoL). Hence, prevalence of PCF and its associated factors, and HRQoL among those who have survived Covid-19 within the general population of Saudi Arabia (KSA) is the subject under examination in this research.

Methods

This cross-sectional study was conducted on 2063 individuals, selected from the KSA's general population, using a non-probability sampling approach. An online survey was used to employ a self-administered questionnaire to the participants, which included socio-demographic information, the patient's COVID-19 infection history, 12-item Short Form Health Survey (SF-12) to assess quality of life, and Chalder Fatigue Scale (CFS) (CFQ 11) to evaluate the extent and severity of fatigue. Data were analyzed using SPSS version 26. A p < 0.05 was considered to be strong evidence against the null hypothesis.

Results

The median age of participants was 34 (IQR = 22) years, with females comprising the majority (66.2%). According to the SF-12 questionnaire, 91.2% of patients experienced physical conditions, and 77% experienced depression. The prevalence of PCF was 52% on CFQ 11 scale. Female gender, higher levels of education, a pre-existing history of chronic disease, as well as the manifestations of shortness of breath and confusion during acute COVID-19 infection, were identified as independent predictors of fatigue.

Conclusion

To facilitate timely and effective intervention for post-acute COVID-19 fatigue, it is essential to continuously monitor the individuals who have recovered from acute COVID-19 infection. Also, it is critical to raise health-education among these patients to improve their quality of life. Future research is required to determine whether COVID-19 survivors would experience fatigue for an extended duration and the impact of existing interventions on its prevalence and severity.

Critical Approach to Hypothyroid Patients With Persistent Symptoms

Hypothyroidism is a common condition, and numerous studies have been published over the last decade to assess the potential risks associated with this disorder when inappropriately treated. The standard of care for treatment of hypothyroidism remains levothyroxine (LT4) at doses to achieve biochemical and clinical euthyroidism. However, about 15% of hypothyroid patients experience residual hypothyroid symptoms. Some population-based studies and international population-based surveys have confirmed dissatisfaction with LT4 treatment in some hypothyroid patients. It is well established that hypothyroid patients treated with LT4 exhibit higher serum thyroxine:triiodothyronine ratios and can have a persistent increase in cardiovascular risk factors. Moreover, variants in deiodinases and thyroid hormone transporter genes have been associated with subnormal T3 concentrations, persistent symptoms in LT4-treated patients, and improvement in response to the addition of liothyronine to LT4 therapy. The American (ATA) and European Thyroid Association (ETA) guidelines have recently evolved in their recognition of the potential limitations of LT4. This shift is reflected in prescribing patterns: Physicians' use of combination therapy is prevalent and possibly increasing. Randomized clinical trials have recently been published and, while they have found no improvement in treating hypothyroid patients, a number of important limitations did not allow generalizability. Meta-analyses have reported a preference rate for combination therapy in 46.2% hypothyroid patients treated with LT4. To promote discussions about an optimal study design, the ATA, ETA, and British Thyroid Association have recently published a consensus document. Our study provides a useful counterpoint on the controversial benefits of treating hypothyroid patients with combination therapy.

The relationship between fatigue and sickness absence from work

Background

Although many studies have been conducted on worker fatigue and sickness absence, the association between fatigue and sickness absence is unclear in Korean workers. This study was conducted to investigate the effect of worker fatigue on future sickness absence.

Methods

The study was conducted on workers who received medical check-ups at a university hospital for two consecutive years (2014-2015). During check-ups in the first year, the Fatigue Severity Scale (FSS) was used to assess fatigue levels, and during check-ups in the second year, sickness absence was surveyed to determine whether they had been absent from work due to physical or mental illness during previous 12 months. The χ2 test was used to analyze relationships between sociodemographic and occupational characteristics, fatigue levels, and sickness absence. Odds ratios (ORs) were calculated by logistic regression analysis controlled for confounding factors.

Results

A total of 12,250 workers were included in the study, and 396 (3.2%) workers experienced more than one day of sickness absence during the study period. Adjusted ORs for sickness absence were 3.35 (95% confidence interval [CI]: 2.64-4.28) in the moderate-fatigue group and 6.87 (95% CI: 4.93-9.57) in the high-fatigue group versus the low-fatigue group. For men in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 3.40 (95% CI: 2.58-4.48) and 8.94 (95% CI: 6.12-13.07), and for women in the moderate- and high-fatigue groups, adjusted ORs for sickness absence were 2.93 (95% CI: 1.68-5.10) and 3.71 (95% CI: 1.84-7.49), respectively.

Conclusions

Worker fatigue is associated with sickness absence during the following 12 months, and this association appears to be stronger for men than women. These results support the notion that sickness absence can be reduced by evaluating and managing work-related fatigue.

A Randomized Trial of Intravenous Iron Supplementation and Exercise on Exercise Capacity in Iron-Deficient Nonanemic Patients With CKD

Introduction

Patients with chronic kidney disease (CKD) are often iron deficient, even when not anemic. This trial evaluated whether iron supplementation enhances exercise capacity of nonanemic patients with CKD who have iron-deficiency.

Methods

Prospective, multicenter double-blind randomized controlled trial of nondialysis patients with CKD and iron-deficiency but without anemia (Hemoglobin [Hb] >110 g/l). Patients were assigned 1:1 to intravenous (IV) iron therapy, or placebo. An 8-week exercise program commenced at week 4. The primary outcome was the mean between-group difference in 6-minute walk test (6MWT) at 4 weeks. Secondary outcomes included 6MWT at 12 weeks, transferrin saturation (TSAT), serum ferritin (SF), Hb, renal function, muscle strength, functional capacity, quality of life, and adverse events at baseline, 4 weeks, and at 12 weeks. Mean between-group differences were analyzed using analysis of covariance models.

Results

Among 75 randomized patients, mean (SD) age for iron therapy (n = 37) versus placebo (n = 38) was 54 (16) versus 61 (12) years; estimated glomerular filtration rate (eGFR) (34 [12] vs. 35 [11] ml/min per 1.73 m2], TSAT (23 [12] vs. 21 [6])%; SF (57 [64] vs. 62 [33]) μg/l; Hb (122.4 [9.2] vs. 127 [13.2] g/l); 6MWT (384 [95] vs. 469 [142] meters) at baseline, respectively. No significant mean between-group difference was observed in 6MWT distance at 4 weeks. There were significant increases in SF and TSAT at 4 and 12 weeks (P < 0.02), and Hb at 12 weeks (P = 0.009). There were no between-group differences in other secondary outcomes and no adverse events attributable to iron therapy.

Conclusion

This trial did not demonstrate beneficial effects of IV iron therapy on exercise capacity at 4 weeks. A larger study is needed to confirm if IV iron is beneficial in nondialysis patients with CKD who are iron-deficient.

The demographic features of fatigue in the general population worldwide: a systematic review and meta-analysis

Background

Fatigue is one of the most common subjective symptoms that impairs daily life and predict health-related events. This study aimed to estimate the prevalence of fatigue in the global population.

Methods

PubMed and the Cochrane Library were used to search for relevant articles from inception to December 31, 2021. Studies with prevalence data of fatigue in the general population were selected and reviewed by three authors independently and cross-checked. Regarding subgroups, adults (≥18 years), minors (<18 years), and specific occupation population (participants in each study being limited to a specific occupational group), and fatigue types and severity, meta-analysis was conducted to produce point estimates and 95% confidence intervals (95% CI).

Results

From the initial 3,432 studies, 91 studies accounting for 115 prevalence data points (623,624 participants) were finally selected. The prevalence of general fatigue (fatigue lasting < 6 months, or fatigue of unspecified duration) was 20.4% (95% CI, 16.7-25.0) in adults, 11.7% (95% CI, 5.2-26.6) in minors, and 42.3% (95% CI, 33.0-54.2) in specific occupations. Chronic fatigue (fatigue lasting more than 6 months) affected 10.1% (95% CI, 8.2-12.5) of adults, 1.5% (95% CI, 0.5-4.7) of minors, and 5.5% (95% CI, 1.4-21.6) of subjects in specific occupations. There was an overall female-predominant prevalence for all subgroup analyses, with a total odds ratio of 1.4 (95% CI, 1.3-1.6). Regarding the severity and presence of medical causes, the total prevalence of moderate fatigue [14.6% (95% CI, 9.8-21.8)] was 2.4-fold that of severe fatigue [6.1% (95% CI, 3.4-11.0)], while unexplained fatigue (fatigue experienced by individuals without any underlying medical condition that can explain the fatigue) was ~2.7-fold that of explained fatigue (fatigue experienced by individuals with a medical condition that can explain the fatigue); as proportion of 40.0% of physical, 8.6% of mental, and 28.4% of mixed cause.

Conclusions

This study has produced the first comprehensive picture of global fatigue prevalence in the general population, which will provide vital reference data contributing to fatigue-related research, including the prevention of diseases.

Systematic review registration

Identifier: CRD42021270498.

Investigating brain cortical activity in patients with post-COVID-19 brain fog

Brain fog is a kind of mental problem, similar to chronic fatigue syndrome, and appears about 3 months after the infection with COVID-19 and lasts up to 9 months. The maximum magnitude of the third wave of COVID-19 in Poland was in April 2021. The research referred here aimed at carrying out the investigation comprising the electrophysiological analysis of the patients who suffered from COVID-19 and had symptoms of brain fog (sub-cohort A), suffered from COVID-19 and did not have symptoms of brain fog (sub-cohort B), and the control group that had no COVID-19 and no symptoms (sub-cohort C). The aim of this article was to examine whether there are differences in the brain cortical activity of these three sub-cohorts and, if possible differentiate and classify them using the machine-learning tools. he dense array electroencephalographic amplifier with 256 electrodes was used for recordings. The event-related potentials were chosen as we expected to find the differences in the patients' responses to three different mental tasks arranged in the experiments commonly known in experimental psychology: face recognition, digit span, and task switching. These potentials were plotted for all three patients' sub-cohorts and all three experiments. The cross-correlation method was used to find differences, and, in fact, such differences manifested themselves in the shape of event-related potentials on the cognitive electrodes. The discussion of such differences will be presented; however, an explanation of such differences would require the recruitment of a much larger cohort. In the classification problem, the avalanche analysis for feature extractions from the resting state signal and linear discriminant analysis for classification were used. The differences between sub-cohorts in such signals were expected to be found. Machine-learning tools were used, as finding the differences with eyes seemed impossible. Indeed, the A&B vs. C, B&C vs. A, A vs. B, A vs. C, and B vs. C classification tasks were performed, and the efficiency of around 60-70% was achieved. In future, probably there will be pandemics again due to the imbalance in the natural environment, resulting in the decreasing number of species, temperature increase, and climate change-generated migrations. The research can help to predict brain fog after the COVID-19 recovery and prepare the patients for better convalescence. Shortening the time of brain fog recovery will be beneficial not only for the patients but also for social conditions.

The prevalence and severity of fatigue in meningioma patients and its association with patient-, tumor- and treatment-related factors

Background

Fatigue is a commonly reported and severe symptom in primary brain tumor patients, but the exact occurrence in meningioma patients is unknown. This study aimed to determine the frequency and severity of fatigue in meningioma patients as well as associations between the level of fatigue and patient-, tumor-, and treatment-related factors.

Methods

In this multicenter cross-sectional study, meningioma patients completed questionnaires on fatigue (MFI-20), sleep (PSQI), anxiety and depression (HADS), tumor-related symptoms (MDASI-BT), and cognitive functioning (MOS-CFS). Multivariable regression models were used to evaluate the independent association between fatigue and each patient-, tumor-, and treatment-related factor separately, corrected for relevant confounders.

Results

Based on predetermined in- and exclusion criteria, 275 patients, on average 5.3 (SD = 2.0) year since diagnosis, were recruited. Most patients had undergone resection (92%). Meningioma patients reported higher scores on all fatigue subscales compared to normative data and 26% were classified as fatigued. Having experienced a complication due to resection (OR 3.6, 95% CI: 1.8-7.0), having received radiotherapy (OR 2.4, 95% CI: 1.2-4.8), a higher number of comorbidities (OR 1.6, 95% CI: 1.3-1.9) and lower educational level (low level as reference; high level OR 0.3, 95% CI: 0.2-0.7) were independently associated with more fatigue.

Conclusions

Fatigue is a frequent problem in meningioma patients even many years after treatment. Both patient- and treatment-related factors were determinants of fatigue, with the treatment-related factors being the most likely target for intervention in this patient population.

[Asthenia, mental fatigue and cognitive dysfunction]

Conditions associated with asthenia are usually characterized by increased fatigue, impaired activities of daily living and decreased productivity. In clinical practice it is important to distinguish between idiopathic chronic fatigue (primary or functional asthenia) and chronic fatigue syndrome (CFS). Fatigue can also be classified by neuromuscular and/or cognitive and mental fatigue. The article discusses the neuroanatomical basis and focuses on the neurocognitive theory of pathological fatigue. In addition the relationship between mental stress, fatigue and cognitive impairments such as subjective cognitive impairment (SCI) and mild cognitive impairment (MCI) are also discussed. We discuss the rationale that for treatment of asthenic conditions accompanied by cognitive dysfunction it is justified to use combination therapy - fonturacetam and a preparation containing nicotinoyl-GABA and Ginkgo Biloba.

Work-related fatigue: A hazard for workers experiencing disproportionate occupational risks

BACKGROUND

Long working hours and fatigue are significant occupational safety and health (OSH) hazards for working populations who experience disproportionate risks of injury and illness. These groups include young or new workers, aging workers, contingent and temporary workers, immigrant and nonnative workers, female workers, minority workers, workers with low levels of education and lower socioeconomic status, and small business employees. An increasing focus on newer determinants of health in the workplace, such as health equity and work-life conflict, in worker populations at greater risk for injury or illness, provides an opportunity for researchers to address the causes and consequences of work-related fatigue in high-risk populations.

METHODS

Articles in the OSH literature that addressed fatigue in higher-risk workers were identified by the authors or recommended by subject matter experts in workplace fatigue as part of a Working Hours, Sleep and Fatigue Forum. Additional articles were identified by searching for a combination of specific at-risk worker group titles (e.g., female workers, temporary workers) with fatigue or working hours.

RESULTS

There remains a paucity of research specifically addressing working hours and fatigue among disproportionately at-risk worker populations. The literature reviewed in this paper suggests that several of these populations are at increased risk of fatigue due to multiple factors, such as irregular shifts, lack of access to fatigue management resources, and socioeconomic barriers.

CONCLUSIONS

More research is needed to identify solutions to address fatigue in working populations who may be at greater risk for its consequences by virtue of adverse socioeconomic and related factors. Interventions to address work-related fatigue in specific at-risk worker groups should also consider the multiple and overlapping categories of risk within these populations.

Longitudinal trajectories of fatigue in early RA: the role of inflammation, perceived disease impact and early treatment response

OBJECTIVE

Fatigue is common in rheumatoid arthritis (RA). We aimed to explore its longitudinal course, predictors and association with disease activity in early RA.

METHODS

Data came from the 2-year treat-to-target trial CareRA (Care in early RA) and its 3-year extension. Fatigue was measured on Visual Analogue Scale, Multidimensional Fatigue Inventory and Short Form-36 (SF-36) vitality. Longitudinal fatigue trajectories were identified with multivariate growth mixture modelling. Early predictors of fatigue and the association of fatigue and its trajectories with disease activity and clinical/psychosocial outcomes were studied with linear mixed models and multilevel mediation.

RESULTS

We included 356 and 244 patients in the 2-year and 5-year analyses, respectively. Four fatigue trajectories were identified: rapid, gradual, transient improvement and early deterioration, including 10%, 14%, 56% and 20% of patients. Worse pain, mental health and emotional functioning were seen in the early deterioration group. Higher pain, patient global assessment (PGA) and disability (Health Assessment Questionnaire), lower SF-36 mental components, and fewer swollen joints at baseline predicted higher fatigue over 5 years, while early disease remission strongly improved 5-year fatigue. The association between Simple Disease Activity Index and fatigue was mediated by PGA, pain, mental health and sleep quality.

CONCLUSIONS

Although fatigue evolves dynamically over time in early RA, most patients do not achieve sustained fatigue improvement despite intensive disease-modifying antirheumatic drug therapy. Higher 5-year fatigue levels were seen in patients with more perceived disease impact and fewer swollen joints at baseline. Conversely, early inflammatory disease control strongly improved long-term fatigue, pointing towards an early window of opportunity to prevent persistent fatigue.

The effect of intravenous iron supplementation on exercise capacity in iron-deficient but not anaemic patients with chronic kidney disease: study design and baseline data for a multicentre prospective double-blind randomised controlled trial

BACKGROUND

Many people living with chronic kidney disease (CKD) are iron deficient, even though they may not be anaemic. The Iron and Muscle study aims to evaluate whether iron supplementation reduces symptoms of fatigue, improves muscle metabolism, and leads to enhanced exercise capacity and physical function. We report here the trial design and baseline characteristics.

METHODS

This is a prospective, double-blind multicentre randomised controlled trial (RCT) including 75 non-dialysis stage 3-4 CKD patients with iron deficiency but without anaemia. Patients were randomly (1:1) assigned to either: i) intravenous iron therapy, or ii) placebo, with concurrent recruitment of eight CKD non-iron deficient participants and six healthy volunteers. The primary outcome of the study is the six-minute walk test (6MWT) distance between baseline and four-weeks. An additional exercise training programme for patients in both groups was initiated and completed between 4 and 12 weeks, to determine the effect of iron repletion compared to placebo treatment in the context of patients undertaking an exercise programme. Additional secondary outcomes include fatigue, physical function, muscle strength, muscle metabolism, quality of life, resting blood pressure, clinical chemistry, safety and harms associated with the iron therapy intervention and the exercise training intervention, and hospitalisations. All outcomes were conducted at baseline, 4, and 12 weeks, with a nested qualitative study, to investigate the experience of living with iron deficiency and intervention acceptability. The cohort have been recruited and baseline assessments undertaken.

RESULTS

Seventy-five individuals were recruited. 44% of the randomised cohort were male, the mean (SD) age was 58 (14) years, and 56% were White. Body mass index was 31 (7) kg/m²; serum ferritin was 59 (45) μg/L, transferrin saturation was 22 (10) %, and haemoglobin was 125 (12) g/L at randomisation for the whole group. Estimated glomerular filtration rate was 35 (12) mL/min/1.73 m² and the baseline 6MWT distance was 429 (174) m.

CONCLUSION

The results from this study will address a substantial knowledge gap in the effects of intravenous iron therapy, and offer potential clinical treatment options, to improve exercise capacity, physical function, fatigue, and muscle metabolism, for non-dialysis patients with CKD who are iron-deficient but not anaemic. It will also offer insight into the potential novel effects of an 8-week exercise training programme.

TRIAL REGISTRATION

EudraCT: 2018-000,144-25 Registered 28/01/2019.

The relevant factors of work-related fatigue for occupational vibration-exposed employees

Background

To date, little is known about the effects of factors linked to work-related fatigue on vibration-exposed workers. Thus, the purpose of this study was (1) to assess the effects of vibration exposure time per week and work-related fatigue on workers and (2) to identify factors associated with work-related fatigue caused by long-term exposure to occupational vibration.

Methods

This study used data collected from the 5th Korean Working Conditions Survey. A total of 34,820 non-vibration-exposed and 10,776 vibration-exposed employees were selected from the data. The χ² and multiple logistic regression were used to determine the effect of vibration exposure time per week and the effects of factors of work-related fatigue on workers.

Results

The prevalence of work-related fatigue in vibration-exposed workers (30.5%) was higher than that of non-exposed workers (15.9%). The prevalence of work-related fatigue was higher for female and workers with depression, anxiety, and shift work, and those with authority to control their work pace had statistically significantly higher odds than those who did not. The employees who had the authority to control their order of work (odds ratio [OR]: 0.88; 95% confidence interval [CI]: 0.81–0.95) and method of work (OR: 0.90; 95% CI: 0.82–0.98) had statistically significantly lower odds than those who did not. The OR of work-related fatigue symptoms was highest among employees whose vibration exposure time per week were 30.0%–40.0% (OR: 2.36; 95% CI: 1.96–2.83). Lower OR was observed as vibration exposure time per week decreased.

Conclusions

The results of the present study suggest an association between occupational vibration and work-related fatigue and longer vibration exposure time per week, causing an increased prevalence of work-related fatigue symptoms. Measures to protect workers exposed to occupational vibration from work-related fatigue must be taken.

Neural mechanism by which physical fatigue sensation suppresses physical performance: a magnetoencephalography study

The right dorsolateral prefrontal cortex (DLPFC) has been proposed to be the brain region regulating performance through fatigue sensation in fatigue, but direct evidence has been lacking for right DLPFC activation when physical performance is suppressed in the presence of fatigue sensation. We examined whether the right DLPFC is activated when physical performance is suppressed by remembering a physical fatigue sensation. Eighteen healthy male volunteers participated. They performed a rest session followed by a handgrip session to induce physical fatigue sensation. Then, they were instructed to remember the state of the right hand with (i.e., the target condition) and without (i.e., the control condition) fatigue sensation as experienced in the handgrip and rest sessions, respectively while performing motor imagery of maximum handgrip of the right hand. Neural activity during both conditions was recorded using magnetoencephalography. The level of fatigue sensation was higher in the target condition than in the control condition. Decreases of handgrip strength and beta band power in the right Brodmann's area 46 were observed in the target condition, suggesting that the right DLPFC is involved in the regulation of physical performance through fatigue sensation. These findings may help elucidate the neural mechanisms regulating performance under fatigue conditions.

Effects of a single dose of tablets containing lactononadecapeptide on cognitive function in healthy adults: a randomized, double-blind, cross-over, placebo-controlled trial

Lactononadecapeptide (LNDP; NIPPLTQTPVVVPPFLQPE) is a memory-improving peptide. The current study aimed to determine the effects of a single dose of tablets containing LNDP on cognitive function in healthy Japanese men aged 30-59 years. A randomized, double-blind, cross-over, placebo-controlled trial was conducted in participants randomly assigned to receive LNDP or placebo tablets. The Uchida-Kraepelin test was used to induce cognitive load in participants as a model of work load. Cognitive function was evaluated using the Japanese version of the CNS Vital Signs. Composite memory and verbal memory were significantly higher following consumption of LNDP than placebo tablets. Carryover effects were observed in attention and concentration domains so that period 1 data was analyzed. LNDP consumption led to higher processing speed, executive function, and cognitive flexibility than placebo. Thus, supplementation with a single dose of LNDP tablets may improve cognitive functions including memory, attention, concentration, and information processing in daily life.

Prevalence and Determinants of Fatigue after COVID-19 in Non-Hospitalized Subjects: A Population-Based Study

This study assessed the prevalence and determinants of fatigue in a population-based cohort of non-hospitalized subjects 1.5-6 months after COVID-19. It was a mixed postal/web survey of all non-hospitalized patients ≥18 years with a positive PCR for SARS-CoV-2 until 1 June 2020 in a geographically defined area. In total, 938 subjects received a questionnaire including the Chalder fatigue scale (CFQ-11) and the energy/fatigue scale of the RAND-36 questionnaire. We estimated z scores for comparison with general population norms. Determinants were analyzed using multivariable logistic and linear regression analysis. In total, 458 subjects (49%) responded to the survey at median 117.5 days after COVID-19 onset, and 46% reported fatigue. The mean z scores of the CFQ-11 total was 0.70 (95% CI 0.58 to 0.82), CFQ-11 physical 0.66 (0.55 to 0.78), CFQ-11 mental 0.47 (0.35 to 0.59) and RAND-36 energy/fatigue -0.20 (-0.31 to -0.1); all CFQ-11 scores differed from those of the norm population (p < 0.001). Female sex, single/divorced/widowed, short time since symptom debut, high symptom load, and confusion during acute COVID-19 were associated with higher multivariable odds of fatigue. In conclusion, the burden of post-viral fatigue following COVID-19 was high, and higher than in a general norm population. Symptoms of fatigue were most prevalent among women, those having a high symptom load, or confusion during the acute phase.

The association of fatigue with dispositional mindfulness: relationships by levels of depressive symptoms, sleep quality, childhood adversity, and chronic medical conditions

Although mindfulness-based interventions may be effective in addressing the common symptom of fatigue, no population-based studies have examined the relationship between mindfulness and fatigue. We determined whether higher levels of dispositional mindfulness were associated with lower levels of fatigue. Cross-sectional data were obtained through the Pennsylvania Head Start Staff Wellness Survey, a 2012 web-based survey in which 2199 of 3375 (65%) eligible staff participated. The analytic sample was restricted to the 2083 female respondents with complete data on dispositional mindfulness (Cognitive and Affective Mindfulness Scale-Revised) and fatigue (Fatigue Severity Scale). We determined the mean covariate-adjusted fatigue scores in each quartile of dispositional mindfulness. This relationship was examined in the overall sample and within subgroups defined by levels of four variables: depressive symptoms, poor sleep quality, childhood adversity, and chronic medical conditions. The sample was 86% non-Hispanic White, and 61% had a bachelor's or more advanced degree. The mean (SD) Fatigue Severity Scale score was 3.3 (1.3). The adjusted mean fatigue score decreased significantly and in a graded manner across higher quartiles of mindfulness, with the adjusted fatigue score 1.4 points lower (95% confidence interval: -1.5, -1.2) among those in the highest quartile of dispositional mindfulness compared to the lowest. This significant graded relationship was present within each subgroup examined, and there was not a statistically significant interaction between dispositional mindfulness and any subgroup variable. Future trials of mindfulness-based interventions should consider assessing the outcome of fatigue in both clinical and non-clinical populations.

Prevalence and factors associated with fatigue in the Lausanne middle-aged population: a population-based, cross-sectional survey

OBJECTIVE

To assess the prevalence and factors associated with fatigue in the general population.

DESIGN

Population-based, cross-sectional survey performed between May 2014 and April 2017.

SETTING

General population of the city of Lausanne, Switzerland.

PARTICIPANTS

2848 participants (53.2% women, age range 45-86 years).

PRIMARY OUTCOME MEASURE

Prevalence of fatigue the previous week, defined as a score of ≥4 using the Fatigue Severity Scale.

RESULTS

The prevalence of fatigue was 21.9% (95% CI 20.4% to 23.4%) in the total sample. On bivariate analysis, participants with fatigue were younger, had a higher body mass index, a lower handgrip strength and lower ferritin levels. Participants with fatigue were more frequently women, had a lower educational level, presented more frequently with clinical insomnia, diabetes, anaemia, depression and low thyroid stimulating hormone (TSH) values, had a higher consumption of antihistamines, antidepressants and hypnotics, and rated more frequently their health as bad or very bad. Multivariable analysis showed that obesity (OR 1.40 (95% CI 1.03 to 1.91)), insomnia categories (p value for trend <0.001), depression (OR 3.26 (95% CI 2.38 to 4.46)), anaemia (OR 1.70 (95% CI 1.00 to 2.89)) and low self-rated health status (p value for trend <0.001) were positively associated with fatigue, while older age (p value for trend 0.002) was negatively associated with fatigue. Conversely, no association was found for diabetes, TSH levels, antihistamines or hypnotics.

CONCLUSION

In a population-based sample aged 45-86, fatigue was present in one out of five subjects. Regarding clinical factors, sleep disturbances such as insomnia and sleep apnoea should be assessed first, followed by depression. Regarding biological factors, anaemia should be ruled out, while screening for hypothyroidism is not recommended as a first step. Sleep complaints and fatigue in older subjects are not due to ageing and should prompt identification of the underlying cause.

The Brugmann Fatigue Scale: An Analogue to the Epworth Sleepiness Scale to Measure Behavioral Rest Propensity

Background: While often confused, fatigue (as opposed to sleepiness) mostly requires rest, not sleep, to recover from. Clinical evaluations of fatigue mainly rely on assessments of symptom intensity, however without taking into account the need to engage in behavioral countermeasures. We therefore developed an 8-item 4-point Likert scale (the Brugmann Fatigue Scale; BFS) sharing a similar conceptual background with the Epworth Sleepiness Scale (ESS), assessing mental and physical fatigue and focusing specifically on rest propensity. Methods: Out of 496 consecutive patients addressed to the sleep unit of an academic hospital, we selected a sample of 295 hypnotic-free subjects (122 females). The present study examines (a) the psychometric properties of the BFS and (b) measurement invariance regarding perceived sleep quality, in parallel with common sleepiness and fatigue scales (ESS and Fatigue Severity Scale; FSS). In addition, (c) correlations of the BFS with clinical scales and polysomnographic variables were explored descriptively. Results: Rasch analyses revealed that the BFS possesses sound psychometric characteristics (rating scale functioning, item fit, dimensionality and measurement invariance) allowing for valid, reliable, linear and unidimensional measurement of mental and physical rest propensity, irrespective of perceived sleep quality, age, or gender. In addition, the BFS was significantly correlated to periodic limb movements during sleep and inversely to REM sleep duration. For both mental and physical subscales, scores above 6 are proposed as cutoff values. Conclusion: In analogy to the ESS, the BFS shows to be a unique and precise instrument assessing symptomatic fatigue with respect to rest propensity.

Investigating causality in the association between vitamin D status and self-reported tiredness

Self-reported tiredness or low energy, often referred to as fatigue, has been linked to low levels of circulating 25-hydroxyvitamin D (25OHD), a biomarker of vitamin D status. Although it is uncertain if the association is causal, fatigue is a common indication for testing, and correcting, low 25OHD-levels. We used two-sample Mendelian randomization to test for genetic evidence of a causal association between low 25OHD-levels and fatigue. Genetic-25OHD associations were estimated from the largest genome-wide association study of vitamin D to date, and genetic-fatigue associations were estimated in 327,478 individuals of European descent in UK Biobank, of whom 19,526 (5.96%) reported fatigue (tiredness or low energy nearly every day over the past two weeks). Using seven genome-wide significant 25OHD-reducing genetic variants, there was little evidence for a causal effect of 25OHD on fatigue (odds ratio for fatigue was 1.05 with 95% confidence interval of 0.87–1.27 per 1-SD decrease in log-transformed 25OHD). There was also little evidence of association between any individual 25OHD-reducing variant and fatigue. Our results suggest that a clinically relevant protective effect of 25OHD-levels on fatigue is unlikely. Therefore, vitamin D supplementation of the general population to raise 25OHD-levels is not likely to be useful in preventing fatigue.

The Silhouettes Fatigue Scale: comprehensibility and validity in older individuals

Purpose: Fatigue has been shown to be one of the key factors that interfere in the quality of life of elderly individuals. In order to understand its impact and evaluate the efficacy of treatments that target fatigue, researchers and clinicians need psychometrically sound and easy to use assessment instruments. The aim of this work was to address this need by evaluating the comprehensibility and validity of the Silhouettes Fatigue Scale (SFS) in a sample of older individuals.Methods: A total of 70 older individuals participated in the study. Participants were interviewed individually and asked to rate their level of fatigue during the week before the interview using the SFS and the FACIT-Fatigue Scale (to help evaluate convergent validity), and respond to the Pain Catastrophizing Scale (to help evaluate discriminant validity).Results: The results indicate that the SFS is understandable and that the scores have an adequate convergent validity and discriminant validity when used with older adults.Conclusions: The SFS is a valid measure of fatigue that can be used with older adults. It fills the need for a brief and easy to administer and score measure, which can be used in situations where assessment burden is a significant issue.Implications for rehabilitationFatigue is a significant problem among the elderly resulting in significant disability, and psychometrically sound and easy to use questionnaires are needed.The Silhouettes Fatigue Scale (SFS) is a new single-item self-report fatigue rating scale.Results show that the SFS is understandable, and that the scores have discriminant and convergent validity when used with older adults.As it does not use written items, it may be more easily understood by people who have basic or even no literacy level, thus making it easier to use for a wider audience.

Effect of chlorogenic acids on fatigue and sleep in healthy males: A randomized, double-blind, placebo-controlled, crossover study

Chlorogenic acids (CGAs) are found in abundance in coffee beans and have numerous health benefits. This study investigated the effect of CGAs extracted from coffee beans on fatigue and sleep in healthy participants. This crossover study involved 16 men (aged 30-54 years) who were daytime workers with weekends off work. The participants were randomized into two groups: One group was given a placebo beverage, and the other was given an active beverage containing 300 mg of CGAs. The test beverages were consumed for 13 days starting on a Sunday. The evaluation criteria were feelings of fatigue and sleep quality, sleep-related indices recorded by an activity meter, and biomarkers. Feelings of fatigue and sleep-related indices during the first (first half of week 1) and second (second half of week 2) halves of the consumption periods were compared. Within the first half of week 1, no differences in feelings of fatigue were observed between the groups. However, during the second half of week 2, fatigue upon awakening and sleep quality in the active group were significantly improved compared with those in the placebo group. Sleep efficiency and total nocturnal awakening time were significantly deteriorated in the second half of week 2 compared with the first half of week 1 in the placebo group. Furthermore, significant differences in these indices were observed between the two groups in the second half of week 2. These results suggest that the daily consumption of CGA-containing beverages may improve fatigue upon awakening and sleep quality.

Bridging Exercise Science, Cognitive Psychology, and Medical Practice: Is "Cognitive Fatigue" a Remake of "The Emperor's New Clothes"?

Fatigue is such a multifaceted construct it has sprouted specific research fields and experts in domains as different as exercise physiology, cognitive psychology, human factors and engineering, and medical practice. It lacks a consensus definition: it is an experimental concept, a symptom, a risk, a cause (e.g., of performance decrement) and a consequence (e.g., of sleep deprivation). This fragmentation of knowledge leads to slower dissemination of novel insights, and thus to a poorer research. Indeed, what may seem as a novel result in one field, may very well be old news in another, hence leading to this "innovation" being a scientific equivalent to the emperor's new clothes. The current paper aims to describe the common denominator in the different areas of expertise where fatigue is investigated. Indeed, rather than focusing on the differences in semantics and conceptualization, we hope that identifying common concepts may be inductive of easier multidisciplinary research. Considering the vastness of fatigue research in all areas identified as relevant-cognitive science, exercise physiology, and medical practice, this analysis has not the ambition to be an exhaustive review in all domains. We have reviewed the fatigue concepts and research in these areas and report the ones that are used to describe the proposed common model to be further investigated. The most promising common feature to cognitive science, exercise physiology and clinical practice is the notion of "perceived effort." This allows to account for interindividual differences, as well as for the situational variations in fatigue. It is applicable to both mental and physical constructs. It integrates motivational and emotional dimensions. It overcomes current polemics in various research fields, and it does not draw on any semantic ambiguity. We thus suggest a new model of fatigue and performance, whether this performance is mental or physical; and whether it is in a clinical range or relates to optimal functioning.

Subjective measures of work-related fatigue in automobile factory employees

BACKGROUND

Work-related fatigue is common among automobile factory employees.

OBJECTIVES

The purpose of this study was to assess fatigue of employees at a Chinese automobile factory.

METHODS

238 employees (119 engineers and 119 workers) participated in this study. The following questionnaires were completed: demographic survey questionnaire, working condition questionnaire (WCQ), functional assessment of chronic illness therapy-fatigue (FACIT-F), subscales of multidimensional fatigue inventory (MFI), and Pittsburgh sleep quality index (PSQI).

RESULTS

Both engineers and workers experienced fatigue. The workers (35.6 years old, SD = 6.7) generally felt more fatigue than engineers (42.6 years old, SD = 6.4). The engineers claimed to be more satisfied with the working conditions than workers. The WCQ showed good properties for assessing work-related factors, which were significantly correlated with fatigue (r = 0.568 for engineers and r = 0.639 for workers). For engineers, general fatigue was observed regularly and frequently, and for workers, physical fatigue usually had a long duration.

CONCLUSIONS

The fatigue was significantly correlated with work-related factors, especially working environment and monotony. For workers, the duration of the work day also affected their fatigue. Some improvements to the working condition in this automobile factory should be considered.

The neural effects of positively and negatively re-experiencing mental fatigue sensation: a magnetoencephalography study

Fatigue sensation is an essential biological alarm that urges us to take rest to avoid disrupting homeostasis and thus plays an important role in maintaining well-being. However, there are situations in which the anticipation of unpleasant fatigue sensation undesirably reduces motivation for activity. The aim of this study was to examine whether thinking positively about the fatigue sensation would increase motivation to accomplish the workload. Fourteen healthy male volunteers participated in this study and performed a two-back test for 30 min to induce mental fatigue sensation. After their subjective level of fatigue had recovered to the baseline level, they re-experienced the fatigue sensation experienced in the two-back test positively, negatively, and without any modification (i.e., re-experienced the fatigue sensation as it was). The level of motivation to perform another two-back test they felt during the re-experiencing was assessed. The neural activity related to the re-experiencing was recorded using magnetoencephalography. The level of the motivation to perform another two-back test was increased by positively re-experiencing the fatigue sensation. The increase in delta band power in Brodmann area 7 was positively associated with the increase in motivation. These results show that positive thinking about fatigue sensation can enhance motivation and suggest that this enhanced motivation may have some effects on visual attention system.

Involvement of the olfactory system in the induction of anti-fatigue effects by odorants

Some components of the neural circuits underlying innate odor-evoked responses have recently been elucidated. Odor information detected by the olfactory receptors is transmitted from the olfactory bulb to the cortical amygdala, where physiological and emotional states such as attraction or avoidance are controlled. Thus, activation of specific olfactory receptors can elicit changes in physiological and/or psychological state. Here, we examined on the odorant Hex-Hex Mix, which has been reported to induce anti-fatigue effects. Fatigue is a prevalent condition that is often related to overwork and psychological stress. Various anti-fatigue treatments have been developed, including supplements and odorants. However, the mechanisms underlying the anti-fatigue effects of these substances are currently unclear. In the present study, we analyzed the involvement of the olfactory system in the mechanisms underlying this effect. We identified the human olfactory receptors activated by Hex-Hex Mix, and evaluated whether activation of these olfactory receptors by a newly developed odorant elicited a similar anti-fatigue effect to Hex-Hex Mix. We assessed anti-fatigue effects with behavioral tests, and 17 healthy males performed the 2-back test as a fatigue-inducing task with or without exposure to the new odorant. Immediately before and after the task, participants performed a cognitive task to evaluate their level of mental fatigue. We found that the difference value of the correct response rate on the cognitive task in the evaluation session was significantly different between in the odorant condition and in the without-odorant condition during the fatigue-inducing session suggesting that the new odorant may improve performance in the fatigue-inducing condition. The results indicated that the new odorant activates the same olfactory receptors as Hex-Hex Mix, which has been reported to induce anti-fatigue effects. Our findings suggest that the olfactory receptors in the olfactory system may be involved in the attenuation of fatigue.

Evidence for unconscious regulation of performance in fatigue

Since fatigue is prevalent in modern societies, it is necessary to clarify the neural mechanisms of fatigue. The regulation of performance through fatigue sensation is one of the mechanisms that decreases performance in fatigue. However, it is unknown whether subjective feeling of fatigue is necessary for the regulation of performance. Here, we examined whether decreased performance occurs without increased fatigue sensation through the experiment which was designed to test if fatigue can be learned unconsciously. Healthy male volunteers performed a fatigue-inducing hand-grip task for 10 min while viewing a target image presented without awareness. On the next day, they viewed a control and the target images presented with awareness and the neural activity caused by viewing the images was measured using magnetoencephalography. Results showed the level of fatigue sensation was not altered but grip-strength was decreased by viewing the target image on the second day. The level of beta band power in Brodmann's area 31 was increased by viewing the target image and this increase was negatively associated with the decrease of grip-strength caused in the hand-grip task. These findings demonstrated that fatigue can be learned unconsciously and that there is a mechanism to decrease performance without fatigue sensation.

Does Tai Chi relieve fatigue? A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Fatigue is not only a familiar symptom in our daily lives, but also a common ailment that affects all of our bodily systems. Several randomized controlled trials (RCTs) have proven Tai Chi to be beneficial for patients suffering from fatigue, however conclusive evidence is still lacking. A systematic review and meta-analysis was performed on all RCTs reporting the effects of Tai Chi for fatigue.

METHODS

In the end of April 2016, seven electronic databases were searched for RCTs involving Tai Chi for fatigue. The search terms mainly included Tai Chi, Tai-ji, Taiji, fatigue, tiredness, weary, weak, and the search was conducted without language restrictions. Methodological quality was assessed using the Cochrane Risk of Bias tool. RevMan 5.3 software was used for meta-analysis. Publication bias was estimated with a funnel plot and Egger's test. We also assessed the quality of evidence with the GRADE system.

RESULTS

Ten trials (n = 689) were included, and there was a high risk of bias in the blinding. Two trials were determined to have had low methodological quality. Tai Chi was found to have improved fatigue more than conventional therapy (standardized mean difference (SMD): -0.45, 95% confidence interval (CI): -0.70, -0.20) overall, and have positive effects in cancer-related fatigue (SMD:-0.38, 95% CI: -0.65, -0.11). Tai Chi was also more effective on vitality (SMD: 0.63, 95% CI: 0.20, 1.07), sleep (SMD: -0.32, 95% CI: -0.61, -0.04) and depression (SMD: -0.58, 95% CI: -1.04, -0.11). However, no significant difference was found in multiple sclerosis-related fatigue (SMD: -0.77, 95% CI: -1.76, 0.22) and age-related fatigue (SMD: -0.77, 95% CI: -1.78, 0.24). No adverse events were reported among the included studies. The quality of evidence was moderate in the GRADE system.

CONCLUSIONS

The results suggest that Tai Chi could be an effective alternative and /or complementary approach to existing therapies for people with fatigue. However, the quality of the evidence was only moderate and may have the potential for bias. There is still absence of adverse events data to evaluate the safety of Tai Chi. Further multi-center RCTs with large sample sizes and high methodological quality, especially carefully blinded design, should be conducted in future research.

REGISTRATION NUMBER

PROSPERO CRD42016033066.

Fatigue in Patients with Autoimmune Thyroid Diseases

Fatigue is a common feature in a wide variety of chronic inflammatory and autoimmune diseases, but fatigue in autoimmune thyroid disease (AITD) has not been investigated so far. The aim of this study was to examine fatigue in patients with AITD and to analyse the correlation between fatigue and the serum concentrations of thyroid antibodies, thyroid function and depression. This cross-sectional clinical study included 62 patients with increased concentrations of thyroperoxidase antibodies (TPOAbs) as confirmation of AITD and 52 healthy individuals who were negative for thyroid antibodies; all controls were euthyroid. Thyroid antibodies, free thyroxine and thyroid-stimulating hormone were measured in the sera of all subjects. The Fatigue Severity Scale was used to measure the severity of fatigue; the level of depression was measured by the Beck Depression Inventory. Eight (12.9%) patients had evident fatigue, 7 (11.3%) patients had fatigue limit values, and 47 (75.8%) patients had no fatigue. The frequency of fatigue was highly significant and almost three times higher in the AITD patients compared to the control group, in which only 2 (3.8%) patients had evident fatigue. The majority of patients with fatigue had normal thyroid function, and only one (1.6%) patient had overt hypothyroidism. Seven (11.3%) patients had both fatigue and depression, whereas one (1.6%) patient had fatigue without depression. We did not find significant correlations between fatigue and the concentrations of thyroid antibodies, but we found statistically significant correlations between fatigue and depression in AITD patients.

The role of psychological factors in fatigue among end-stage kidney disease patients: a critical review

Fatigue is a common and debilitating symptom, affecting 42-89% of end-stage kidney disease patients, persisting even in pre-dialysis care and stable kidney transplantation, with huge repercussions on functioning, quality of life and patient outcomes. This paper presents a critical review of current evidence for the role of psychological factors in renal fatigue. To date, research has concentrated primarily on the contribution of depression, anxiety and subjective sleep quality to the experience of fatigue. These factors display consistent and strong associations with fatigue, above and beyond the role of demographic and clinical factors. Considerably less research is available on other psychological factors, such as social support, stress, self-efficacy, illness and fatigue-specific beliefs and behaviours, and among transplant recipients and patients in pre-dialysis care. Promising evidence is available on the contribution of illness beliefs and behaviours to the experience of fatigue and there is some indication that these factors may vary according to treatment modality, reflecting the differential burdens and coping necessities associated with each treatment modality. However, the use of generic fatigue scales casts doubt on what specifically is being measured among dialysis patients, illness-related fatigue or post-dialysis-specific fatigue. Therefore, it is important to corroborate the available evidence and further explore, qualitatively and quantitatively, the differences in fatigues and fatigue-specific beliefs and behaviours according to renal replacement therapy, to ensure that any model and subsequent intervention is relevant and grounded in the experiences of patients.

Co-occurrence and symptomatology of fatigue and depression

OBJECTIVE

Fatigue and depression are highly comorbid phenotypes with partially overlapping symptoms. The main aims of the present study are to: (i) identify the risk of current fatigue and depression; (ii) determine if the depression symptoms experienced by individuals who are fatigued (N=766) and non-fatigued (N=1849) are different; and (iii) identify if the fatigue symptoms experienced by depressed (N=275) and non-depressed (N=2340) individuals are different, in a community-based sample of Australian twins aged over 50years.

METHODS

Fatigue and depression symptom profiles and classifications were generated using the Schedule of Fatigue and Anergia (SOFA); the General Health Questionnaire; and the Delusions-Symptoms-States Inventory, States of Anxiety and Depression questionnaires. The association between co-occurring fatigue and depression was assessed using prevalence ratios. Differences in the preponderance of fatigue and depression symptoms were assessed using logistic regression modeling.

RESULTS

Individuals with either fatigue or depression have an approximately two-fold increased risk for comorbid presentation of both traits, compared to the general population. Logistic regression analysis indicated that fatigued individuals were significantly more likely to report all of the Diagnostic and Statistical Manual of Mental Disorders (DSM) depression symptoms assessed in the study. Similarly, depressed individuals were significantly more likely to report all SOFA fatigue symptoms.

CONCLUSIONS

Fatigue and depression are highly correlated traits within the community. Depression symptomatology and prevalence are significantly increased in fatigued individuals. Fatigue and especially the symptoms of insomnia and poor concentration are strong predictors of depression. Notably, the association between fatigue and depression is independent of their overlapping symptomatology. Therefore, presentation with fatigue, and in particular the symptoms of insomnia and poor concentration, should be considered as warning signs of depression in older adults.

Neurasthenia and Chronic Fatigue: Theory and Practice in Britain and America

The symptoms that make up the construct of neuras thenia, including fatigue and exhaustion, are dimension ally distributed in the community. The decision to create a category called neurasthenia is an arbitrary one, influenced by issues of severity and morbidity. The prevalence and nature of the resulting concept are also substantially influenced by the decision on how to classify the close relationships among excessive fatigue, depression and anxiety. Superimposed upon this classi fication is a second, parallel structure of illness beliefs. The original construct of neurasthenia as a physical disease that resulted from overwork, was of consider able utility to both doctors and patients. This early concept of neurasthenia can be recognized in the modem revival of interest in chronic fatigue syndrome (CFS) in Western cultures. The current highly charged atmosphere surrounding these diagnoses reflects the issues of legitimacy and non-legitimacy in illness, usually expressed in competing physical and psychologi cal explanations of ill health.

Fatigue and Activity Patterns of People with Chronic Fatigue Syndrome

Although fatigue is the central symptom of people with chronic fatigue syndrome (CFS), relatively few reports in the literature examine the severity of this fatigue or the activity patterns of people with CFS. Using the Fatigue Severity Scale, the Nottingham Health Profile, the Human Activity Profile, and the Activity Record, severity of fatigue, health status, and activity patterns were investigated. People with CFS reported significantly higher levels of fatigue, poorer health status, and engagement in less energy-demanding activities ( P<0.001) than people without CFS. Those with CFS spent 16.18% (standard deviation [SD]=9.62) of their time resting compared with only 2.28% (SD=3.26) of the time spent by those without CFS ( P<0.05). Time spent in productive activities (household activities and work) was also significantly different, with the CFS group less involved ( P<0.05). This severity of fatigue and limitations in activity patterns warrant further attention. Frequent rest periods and energy conservation training may benefit these clients.

Fatigue Severity among African Americans: Gender and Age Interactions

The present study investigated the relationship between fatigue, age, and gender in a multiculturally and socioeconomically diverse community-based urban sample. The impact of age and gender on fatigue severity was examined in a group of 3,692 African Americans and then compared to results from 9,717 Caucasians and 3,450 Latinos. Findings indicated that for African Americans, there was a significant gender by age interaction. African American women had significantly higher rates of fatigue when compared to African American men. Older African American men had significantly higher rates of fatigue than younger African American men. However, there was no significant difference in the levels of fatigue reported by younger and older African American women. An age and gender interaction was also present for the Caucasian sample but not for the Latino sample. Findings suggest that age and gender are important in predicting the severity of fatigue in an African American sample.

A Community-based Study of Prolonged Fatigue and Chronic Fatigue

Previous estimates of the prevalence of fatigue and chronic fatigue have derived largely from treated populations and have been biased by differential access to health-care treatment linked with gender, racial/ethnic and social class status. This study involves a community-based prevalence study of prolonged fatigue and chronic fatigue. It addresses: (1) the rate of prolonged fatigue and chronic fatigue in a socioeconomically and ethnically diverse sample of 28,673 adults in Chicago; and (2) establishes the relative prevalence of prolonged fatigue and chronic fatigue across race/ethnicity, socio-economic status and gender. Univariate and multivariate statistical techniques were utilized to delineate the overall rate of prolonged fatigue and chronic fatigue in the Chicago population and its relative prevalence by gender, race/ethnicity, and social class. Findings indicated that fatigue is common in urban populations, but that prolonged fatigue and chronic fatigue occur in about 5.00 to 7.68 percent and 2.72 to 4.17 percent, respectively, of the sample of the population. Highest levels of fatigue were consistently found among women and those with lower levels of education and occupational status.

Influence of Medication on Fatigue Six Months after Stroke

Poststroke fatigue (PSF) is frequent and affects patients' quality of life. Medication use was hypothesized as being responsible for PSF. Our objective was to evaluate potential relationships between 6-month PSF and medication use at discharge and 6 months after an ischemic stroke. This study is part of STROKDEM, an ongoing longitudinal cohort study, whose main aim is to determine predictors of poststroke dementia. Patients were included within 72 hours after an ischemic stroke and followed up with standardized evaluations. Medication use 7 days and 6 months after stroke was rated, and polypharmacy was defined as the number of categories of treatments received by a patient. PSF was evaluated using the Chalder Fatigue Scale. Medical history, vascular risk factors, depression, anxiety, and sleep disturbances were evaluated. One hundred and fifty-three patients were included: 52.9% presented PSF. PSF at 6 months was not predicted by medication use at discharge nor associated with medication use at month 6. We found severity of PSF to be increased in patients with polypharmacy. Our results suggest that PSF is not a side effect of drugs use, which more reflects presence of disturbances frequently observed after stroke such as depression, anxiety, or sleep disturbances. Clinical study is registered on clinicaltrials.gov (NCT01330160).

Neural mechanisms to predict subjective level of fatigue in the future: a magnetoencephalography study

Fatigue is a major contributor to workplace accidents, morbidity, and mortality. To prevent the disruption of homeostasis and to concurrently accomplish an assigned workload, it is essential to control the level of workload based on the subjective estimation of the level of fatigue that will be experienced in the near future. In this study, we aimed to clarify the neural mechanisms related to predicting subjective levels of fatigue that would be experienced 60 min later, using magnetoencephalography. Sixteen healthy male volunteers participated in this study. In relation to the prediction, a decrease of alpha band power in the right Brodmann’s area (BA) 40 and BA 9 at 1200 to 1350 ms and that in the right BA 9 at 1350 to 1500 ms, and a decrease of gamma band power in the right BA 10 at 1500 to 1650 ms were observed. In addition, the decreased level of alpha band power in BA 9 at 1200 to 1350 ms was positively associated with the daily level of fatigue. These findings may help increase our understanding of the neural mechanisms activated to indicate the need to take a rest based on the prediction of the subjective fatigue in the future.

The neural mechanisms of re-experiencing physical fatigue sensation: a magnetoencephalography study

It has been hypothesized that fatigue sensation impairs the ability and efficiency to perform activities and can be a cause of fatigue itself. As such, it is important to clarify the neural mechanisms of fatigue sensation. The re-experiencing of mental fatigue sensation involves brain regions including Brodmann's area (BA) 40, BA 39, and the pulvinar nucleus. In the present study, we examined neural activity caused by re-experiencing a physical fatigue sensation that had been experienced. Fifteen healthy male volunteers participated in fatigue and control experiments in a crossover fashion. In the fatigue experiment, participants performed a handgrip task for 10 min to induce a physical fatigue sensation and then re-experienced the physical fatigue sensation during magnetoencephalography (MEG) session. In the control experiment, they did not perform the handgrip task but re-experienced the sensation without physical fatigue in an MEG session. Neural activity related to re-experiencing physical fatigue sensations of the right hand (right condition), left hand (left condition), and related to listening to the auditory cues (sound condition) was assessed using spatial filtering analyses of the MEG data. Changes in oscillatory band power in some brain regions, including BA 40, were common between the right and left conditions. A part of the neural activity related to the re-experiencing physical fatigue sensation, such as the decrease in alpha (8-13 Hz) band power in the BA 40, was also observed in the sound condition. These findings may help to understand the neural mechanisms related to intentionally and unintentionally re-experiencing physical fatigue sensation.

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

Background and Objectives

Prolonged 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.

Methods

A 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.

Results

A 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.

Conclusion

Our 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.

Fatigue as a manifestation of psychosocial distress in a low-income country: a population-based panel study

OBJECTIVE

Fatigue is a common complaint worldwide and associated with disability and high health service use costs. We tested the hypothesis that maternal fatigue would be associated independently with maternal common mental disorder ('maternal CMD') in a rural, low-income country setting.

METHODS

The analysis was conducted using data from a population-based cohort located in the Butajira demographic surveillance site, Ethiopia. A total of 1065 women were recruited in pregnancy and followed up to 2.5 (n = 1009; 94.7%) and 3.5 years post-partum (n = 989; 92.9%). Maternal CMD symptoms were measured using a locally validated version of the Self-Reporting Questionnaire and fatigue was measured using a dichotomised item from the Patient Health Questionnaire-15. Physical health indicators included haemoglobin level, body mass index and illness episodes. Generalised estimating equations were used to conduct hypothesis-driven and exploratory multivariable analyses in the panel at 2.5 and 3.5 years.

RESULTS

The prevalence of maternal fatigue was 8.3% at 2.5 years and 5.5% at 3.5 years post-partum. Psychological symptoms of maternal CMD were associated independently with complaints of fatigue after adjusting for anaemia, body mass index, physical ill health, poverty and other confounding variables: adjusted odds ratio (aOR), 1.46; 95% confidence interval (CI), 1.28-1.66 for each one point increase in SRQ score. In the multivariable model, only psychosocial factors (CMD and stressful life events) and self-reported physical ill health were associated significantly with complaints of fatigue.

CONCLUSION

Complaints of fatigue are associated strongly with maternal CMD and other psychosocial risk factors in this rural, low-income country setting with a high burden of undernutrition and infectious disease. Fatigue should be understood as a potential indicator of CMD in primary care to improve detection and treatment.

A Transcriptional Signature of Fatigue Derived from Patients with Primary Sjögren's Syndrome

Background

Fatigue is a debilitating condition with a significant impact on patients’ quality of life. Fatigue is frequently reported by patients suffering from primary Sjögren’s Syndrome (pSS), a chronic autoimmune condition characterised by dryness of the eyes and the mouth. However, although fatigue is common in pSS, it does not manifest in all sufferers, providing an excellent model with which to explore the potential underpinning biological mechanisms.

Methods

Whole blood samples from 133 fully-phenotyped pSS patients stratified for the presence of fatigue, collected by the UK primary Sjögren’s Syndrome Registry, were used for whole genome microarray. The resulting data were analysed both on a gene by gene basis and using pre-defined groups of genes. Finally, gene set enrichment analysis (GSEA) was used as a feature selection technique for input into a support vector machine (SVM) classifier. Classification was assessed using area under curve (AUC) of receiver operator characteristic and standard error of Wilcoxon statistic, SE(W).

Results

Although no genes were individually found to be associated with fatigue, 19 metabolic pathways were enriched in the high fatigue patient group using GSEA. Analysis revealed that these enrichments arose from the presence of a subset of 55 genes. A radial kernel SVM classifier with this subset of genes as input displayed significantly improved performance over classifiers using all pathway genes as input. The classifiers had AUCs of 0.866 (SE(W) 0.002) and 0.525 (SE(W) 0.006), respectively.

Conclusions

Systematic analysis of gene expression data from pSS patients discordant for fatigue identified 55 genes which are predictive of fatigue level using SVM classification. This list represents the first step in understanding the underlying pathophysiological mechanisms of fatigue in patients with pSS.