Etiology Of Fatigue Research Articles

Physical activity and physical fitness in lymphoma patients before, during, and after chemotherapy: a prospective longitudinal study

Fatigue is a common and distressing symptom in cancer patients, especially in lymphoma patients. One hypothesized mechanism in the etiology of fatigue is a vicious circle between fatigue, physical inactivity, and deconditioning. However, the natural evolution of physical activity and physical fitness over the course of treatment is unknown. Therefore, the aim of this longitudinal study was to assess fatigue, physical activity, and physical fitness in lymphoma patients before, during, and after treatment. Fatigue was measured with the EORTC-QLQ-C30, physical activity with an accelerometer, and physical fitness with a maximal incremental cycle ergometer test, 6-min walking distance test, and muscle strength measurements. Differences between the three measurement moments and baseline differences between Hodgkin lymphoma and non-Hodgkin lymphoma, early and advanced disease, were analyzed. Twenty-nine patients were included. Functional exercise capacity and quadriceps force were impaired before the start of treatment (86 ± 15 and 82 ± 16 % of predicted value, respectively). Over the course of treatment, significant declines were found in hemoglobin, quadriceps force, handgrip force, and maximal oxygen uptake, while patients reported more fatigue (p values < 0.016). Fatigue was significantly correlated with hemoglobin (r = -0.49), physical activity (r = 0.81), and physical functioning (r = -0.44). Large interindividual variations were found. The present study partially confirmed the hypothesized vicious circle between fatigue, physical inactivity, and deconditioning. Further research with larger samples and longer follow-up is needed to identify factors associated with individual variation in the evolution of fatigue, physical activity, and physical fitness.

THU0479-HPR What do we know about self-reported fatigue in systemic lupus erythematosus?

BackgroundFatigue is one of the most complex and ill understood symptoms of chronic illness often reported as the number one complaint by patients with systemic lupus erythematosus (SLE).ObjectivesThis paper aims...

Comparison of neuromuscular adjustments associated with sustained isometric contractions of four different muscle groups

The extent and characteristics of muscle fatigue of different muscle groups when subjected to a similar fatiguing task may differ. Thirteen healthy young men performed sustained contractions at 50% maximal voluntary contraction (MVC) force until task failure, with four different muscle groups, over two sessions. Per session, one upper limb and one lower limb muscle group were tested (knee extensors and thumb adductor, or plantar and elbow flexors). Changes in voluntary activation level and contractile properties were derived from doublet responses evoked during and after MVCs before and after exercise. Time to task failure differed (P < 0.05) between muscle groups (220 ± 64 s for plantar flexors, 114 ± 27 s for thumb adductor, 77 ± 25 s for knee extensors, and 72 ± 14 s for elbow flexors). MVC force loss immediately after voluntary task failure was similar (-30 ± 11% for plantar flexors, -37 ± 13% for thumb adductor, -34 ± 15% for knee extensors, and -40 ± 12% for elbow flexors, P > 0.05). Voluntary activation was decreased for plantar flexors only (from 95 ± 5% to 82 ± 9%, P < 0.05). Potentiated evoked doublet amplitude was more depressed for upper limb muscles (-59.3 ± 14.7% for elbow flexors and -60.1 ± 24.1% for thumb adductor, P < 0.05) than for knee extensors (-28 ± 15%, P < 0.05); no reduction was found in plantar flexors (-7 ± 12%, P > 0.05). In conclusion, despite different times to task failure when sustaining an isometric contraction at 50% MVC force for as long as possible, diverse muscle groups present similar loss of MVC force after task failure. Thus the extent of muscle fatigue is not affected by time to task failure, whereas this latter determines the etiology of fatigue.

Fatigue in IBD Is Related to Poor Quality of Life And Sleep, Not Inflammation

Fatigue is common in patients with Inflammatory Bowel Disease (IBD), and the etiology is likely multifactorial. The aim of our study was to identify factors associated with fatigue. We conducted a retrospective chart review of consecutive adult patients enrolled in the IBD registry between 7/2010 and 5/2011 in a tertiary care clinic. Crohn's disease (CD) and ulcerative colitis (UC) disease severity was measured with either Harvey-Bradshaw Index (HBI) or the UC Activity Index (UCAI), respectively. Labs were obtained to measure anemia, vitamin deficiencies, and inflammatory markers. Fatigue was defined by Item-1 of the Short IBD Questionnaire (SIBDQ), a quality of life (QOL) measure, which is scored on a 7-point Likert scale. Threshold for fatigue was defined as ‘some of the time’. The selection of fatigue threshold on SIBDQ was validated using the Patient Reported Outcomes Measurement Information System (PROMIS) fatigue scale on a subset of patients (n = 40; r = 0.67; P < 0.001). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Patients with and without fatigue were assessed for differences in baseline characteristics using t-tests (continuous variables) and chisquare tests (categorical variables). Use of psychotropic medications and narcotics were assessed between patients as proxy measures of psychopathology and pain. There were 781 patients enrolled in the registry; 37.4% UC and 62.6% CD. Of these, 695 (258 UC, 437 CD) completed the SIBDQ at the office visit. Many (58%) patients had fatigue at time of evaluation: 401 reported fatigue ‘all the time’, ‘most of the time’, ‘good bit of the time’, or ‘some of the time’, whereas 294 recorded fatigue ‘a little of the time’, ‘hardly any of the time’, or ‘none of the time’ on Item-1. Fatigue correlated significantly with sleep disturbance (PSQI), QOL (total SIBDQ), and HBI/UCAI scores for the entire population and also when stratified into UC and CD cohorts. These findings were also clinically significant; sleep and QOL scores were clinically impaired in patients with fatigue. More females than males reported fatigue and a higher percentage had CD. There was no difference in C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hemoglobin, vitamin B12, and albumin levels between patients with fatigue and those without, however this may be due to our smaller sample size assessing those variables. Patients with fatigue had decreased QOL (lower total SIBDQ score) and also had greater sleep disturbance (higher PSQI scores). While disease severity did have an association with fatigue, it appeared more related to symptom burden rather than elevated inflammatory markers. Patients with fatigue were more likely to be taking psychotropic medications and/or narcotics, suggesting that psychopathology and pain may play a role in etiology of fatigue. Interestingly, the impact of inflammation or anemia on fatigue was less than the impact of sleep disturbance. These findings suggest that better understanding of pathways to fatigue can inform comprehensive treatment of IBD patients. Future studies will need to assess the predictive relationships between sleep, psychopathology and disease activity and also the impact of IBD-related medications.

Fatigue, brain, behavior, and immunity: Summary of the 2012 Named Series on fatigue

The focus on fatigue for the 2012 Named Series in brain, behavior, and immunity reflects the growing wave of research examining immune underpinnings of fatigue in healthy and clinical populations. Fatigue is prevalent in the general population and in patients with a variety of medical conditions. However, the etiology of fatigue remains elusive. Psychoneuroimmunological approaches to fatigue have yielded important advances in our understanding of this complex symptom and are represented in the twelve articles included in the Named Series. These articles include animal and human models of fatigue and cross a variety of different medical conditions, including cancer, chronic fatigue syndrome, and diabetes. This review briefly summarizes the articles included in the series and highlights the themes that have emerged from this body of work.

Towards continuous mental stress level estimation from physiological signals

The focus on fatigue for the 2012 Named Series in brain, behavior, and immunity reflects the growing wave of research examining immune underpinnings of fatigue in healthy and clinical populations. Fatigue is prevalent in the general population and in patients with a variety of medical conditions. However, the etiology of fatigue remains elusive.Psychoneuroimmunological approaches to fatigue have yielded important advances in our understanding of this complex symptom and are represented in the twelve articles included in the Named Series. These articles include animal and human models of fatigue and cross a variety of different medical conditions, including cancer, chronic fatigue syndrome, and diabetes. This review briefly summarizes the articles included in the series and highlights the themes that have emerged from this body of work.

What do we know about self-reported fatigue in systemic lupus erythematosus?

Fatigue is one of the most complex and ill understood symptoms of chronic illness often reported as the number one complaint by patients with systemic lupus erythematosus (SLE). This paper aims to provide a comprehensive review of the literature on fatigue in SLE. A pool of 55 relevant articles was retrieved via electronic searches of six databases including MEDLINE, EMBASE, CINAHL, AMED, PsychINFO and PubMed. Fatigue in the studies reviewed was assessed by a range of self-report instruments, the content of which is varied. The results displayed a consensus on the high prevalence of fatigue in SLE, which is significantly higher when compared with controls. The aetiology of fatigue appears to be multifactorial. Disease activity is not always significantly associated with fatigue, in comparison with other secondary features of SLE and psychological variables. The literature is limited by the cross-sectional nature of most of the studies, which does not permit for any firm conclusion regarding the direction of causal relationships to be made. The high prevalence of fatigue in SLE emphasizes the need for further detailed prospective research to inform the understanding of its aetiology, course and management.

脊柱起立筋の酸素供給と筋活動におよぼす前屈姿勢の影響

In the workplace, localized muscle fatigue can be a limiting factor for prolonged static work. It is important to study the etiology of fatigue in the muscle to prevent discomfort and potential muscle injury. The purpose of this study was to investigate the effect of sustained trunk flexion and loading on the erector spinae muscles (ESM) fatigue using electromyography (EMG) and muscle oxygenation (Mox) changes. Twelve healthy male volunteers, aged between 19 and 28 years (mean age 23 +/- 2.6), participated in this study. The subjects held a load (5, 10 and 15 kg) and no load in their hands whilst sustaining trunk flexion at 60 degrees and also in an upright standing posture for 30 seconds. Five minutes rest was given between the conditions, and each condition was randomly repeated three times. Surface EMG and near-infrared spectroscopy were recorded. Root mean square and median frequency (MF) of EMG, and Mox were calculated. The results showed a greater decrease in Mox with an increase in loads over time (P = 0.015). Using unloaded trunk flexion as a control to ascertain load effect resulted in a significant difference in Mox in the unloaded condition and in the 15 kg condition (P = 0.027). EMG results showed a significant decrease in the MF over time in trunk flexion while holding a load (P < 0.001). These results show objectively that trunk flexion while holding loads causes ESM fatigue.

Altered Circadian Rhythms and Cancer-Related Fatigue Outcomes

Fatigue is one of the most frequent and distressing complaints reported by patients with cancer. Describing relationships among disrupted circadian rhythms and cancer-related fatigue is important to the design and testing of interventions that target specific underlying etiology of fatigue. The purpose of this article is to review the literature on whether evidence exists to support the notion that disrupted circadian rhythms provide a mechanism of cancer-related fatigue. Searches were conducted from January 1950 to January 2010, to locate pertinent articles using 4 electronic databases: PubMed, MEDLINE, CINAHL, and Scopus. After reviewing the articles, 15 were selected as meeting the established criteria of the study and were critiqued. Statistical approaches varied across studies, which may influence generalizability of results. Although commonalities across studies did emerge, there was a lack of consistency in variables studied, and most studies did not identify a theoretical framework. More research needs to be conducted using consistent types and characteristics of disrupted circadian rhythms in relation to fatigue, including temporal relationships between circadian rhythms, fatigue, and cancer.

Aetiology of fatigue in Sri Lanka and its overlap with depression

Fatigue is a common symptom in Western high-income countries but is often medically unexplained and little is known about its presentation in other populations. To explore the epidemiology and aetiology of fatigue in Sri Lanka, and of its overlap with depression. A total of 4024 randomly selected twins from a population-based register in Sri Lanka (Colombo district) completed home interviews including the Chalder Fatigue Questionnaire. The prevalence of fatigue was similar to that in other countries, although prolonged fatigue may be less common. There was substantial comorbidity with a screen for lifetime depression. Non-shared environmental factors made the largest contributions, although genetic/family factors also contributed. The aetiology appeared consistent across the spectrum of severity. The aetiology of fatigue is broadly similar in Sri Lanka and Western high-income countries. Abnormal experiences of fatigue appear to be the extreme form of more common fatigue, rather than representing independent entities with different genetic or environmental risk factors.

Frontal networks play a role in fatigue perception in multiple sclerosis.

Fatigue, an overwhelming lack of physical or mental energy, is a common complaint in patients affected by multiple sclerosis (MS). Although different mechanisms have been proposed to explain MS-related fatigue, injury of distinct anatomical networks seems to be relevant in fatigue etiology. Particularly, theories point to fronto-striatal network pathological changes as a possible neural basis of fatigue. To investigate the role of fronto-striatal white matter structural alterations in fatigue perception we prospectively recruited 40 relapsing remitting patients with MS and 15 healthy controls. In patients with MS, fatigue was assessed using a validated measure, the Modified Fatigue Impact Scale (MFIS; Kos et al., 2005). Brain MRI scans were acquired for each subject enrolled with diffusion tensor imaging. Diffusion tensor data were correlated with MFIS scores using voxel-wise analysis of fractional anisotropy maps and fiber tractography algorithms. A significant cluster of voxels correlating with fatigue scores located in the deep left frontal white matter was identified. Fiber tractography revealed the cluster to be included in a complex fronto-frontal, fronto-striatal, fronto-occipital, and fronto-limbic network. Structural properties of the traced white matter fiber bundles correlated with fatigue perception and patients with clinically relevant fatigue were found to present reduced white matter integrity in the aforementioned tracts compared to those with lower levels of fatigue. Our observations show a significant involvement of different frontal networks in the pathophysiology of fatigue, thus accounting for the multifaceted nature of this disabling symptom.

Fatigue, Endocrinopathies, and Metabolic Disorders

Abstract Fatigue is a frequent reason for seeking medical attention. Endocrine dysfunction is a common etiology of fatigue. In fact, thyroid function is usually one of the first explanations on the list of possible diagnoses. The symptoms associated with endocrinopathies are frequently “nonspecific,” and psychiatric disease or psychological disorders need to be differentiated. Often, this can be accomplished using biological measures of hormone function, such as measures of thyroid, pituitary, parathyroid, and adrenal hormone levels. The field of endocrinology is highly dependent on an algorithmic approach to differential diagnosis using hormone levels as the guide. The use of self-reports helps identify at-risk patients, and raises suspicions about whether there is an abnormality, but diagnosis is dependent on laboratory values. Metabolic abnormalities, such as hyper- or hypoglycemia, dyslipidemia, and gonadal dysfunction can also contribute to fatigue. A better understanding of the interactions among hormones, their releasing factors, and regulation of inflammation will help identify abnormalities early and help distinguish endocrinopathies from other causes of fatigue. Early identification of these abnormalities may reduce end-organ damage and improve treatment strategies.

A pilot observational study of the association between fatigue after stroke and C-reactive protein

The aetiology of fatigue after stroke is unknown. We explored the relationship between fatigue and C-reactive protein (CRP) as a marker of inflammation. This cross-sectional study recruited inpatients with a stroke (onset within the previous three months) over a five-week period. Those with dysphasia or confusion severe enough to prevent informed consent and those with current infection were excluded. A semi-structured interview determined a) fulfillment of a case definition for fatigue and b) severity of fatigue (fatigue assessment scale, FAS). Venous blood was taken for CRP. A hospital anxiety and depression score (HADS) was used to screen for emotional distress. Of the 28 patients recruited (mean age 72.7 years, proportion men 47%), 15 (53%) fulfilled the case definition for fatigue. C-reactive protein data were logarithmically transformed for analysis. C-reactive protein levels did not differ significantly between those with and without fatigue, according to the case definition (=28, p=0.35). After exclusion of those with pre-stroke fatigue and those with high scores on the HADS (suggestive of emotional distress), the geometric mean CRP of the fatigued group was 16.04 mg/l (95% CI: 7.12-36.14) compared with 5.16 mg/l (95% CI: 2.7-9.85) in the non-fatigued group (n=21, p=0.025, unpaired t test), but the relationship between FAS and CRP was not statistically significant (r=0.37, p=0.098). This pilot study is the first to demonstrate an association between fatigue after stroke and higher CRP, after excluding patients with pre-stroke fatigue and those with probable mood disorders. If this finding is confirmed in a larger number of patients, it might provide a target for treating fatigue after stroke.

Outcomes of a Cancer-Related Fatigue Clinic in a Comprehensive Cancer Center

Cancer-related fatigue (CRF) is a significant issue for cancer patients and frequently precipitates increased stress and anxiety for patients and caregivers alike. CRF may present well after the initial phase of cancer diagnosis and treatment, regardless of whether the cancer is in remission, widely metastatic, or somewhere in between. Determining whether the etiology of fatigue is potentially reversible and whether it is an effect of treatment or another unrelated cause is often perplexing. Because of the significant impact of CRF on patients at our institution, we organized a CRF clinic and began evaluating patients for fatigue in 1998. Our goal has been to initiate a more focused and, at the same time, more comprehensive effort in educating, evaluating, and treating CRF. The purpose of this report was to present a retrospective review of patients treated in our CRF clinic between 1998 and 2005, to examine the outcomes of our patients, and to briefly describe some of the challenges encountered in treating these patients. This information may help reassess and improve approaches in addressing CRF and subsequently improve fatigue in these patients.

Fatigue in sarcoidosis: a systematic review

Several studies have investigated fatigue among sarcoidosis patients. The purpose of this review is to analyze published data on the assessment, prevalence, etiology, and treatment of sarcoidosis-associated fatigue. Fatigue was identified as a prominent problem in sarcoidosis, and its presence was frequently associated with impaired quality of life, compared with patients without fatigue. Although the studies with good methodological fatigue assessment found no relationship between clinical parameters and fatigue in sarcoidosis patients, the remaining studies reported associations between fatigue and clinical and psychological parameters. No studies were designed to analyze the etiology of fatigue, but some studies showed that prednisone-treated patients reported more fatigue compared with untreated patients. In addition, only one study focused on a treatment for fatigue, dexmethylphenidate hydrochloride. Several instruments to measure fatigue were used, with the Fatigue Assessment Scale most frequently utilized. This review illustrates the importance of fatigue as an under-recognized complication of sarcoidosis. It further emphasizes the need for longitudinal prospective studies to better define sarcoidosis fatigue, explore its impact on quality of life, define aggravating or alleviating factors and evaluate new potential treatment strategies.

Future directions for investigation of fatigue in chronic hepatitis C viral infection

Fatigue is a common and often debilitating symptom for people living with chronic hepatitis C viral infection. Numerous published reports in the past decade have attempted to address the nature and aetiology of fatigue in chronic hepatitis C; however, this field is plagued with lack of clarity about how hepatitis C virus (HCV)-related fatigue occurs and when it is experienced by the infected person. Consequently, both patients and clinicians alike are unclear about how to mediate or prevent the negative consequences of HCV-related fatigue. In the following article, the authors identify areas of ambiguity and incongruity that have evolved primarily from the underlying assumptions and methodological decisions of researchers in the field of HCV-related fatigue. Research related to fatigue in chronic illness is drawn upon to suggest future directions for investigations and interventions in the field of HCV-related fatigue. Future research needs to move beyond the subjective symptomatology of HCV-related fatigue and begin to account for the multidimensional and contextualised nature of the fatigue experience.

Application of near-infrared spectroscopy in preventing work-related musculoskeletal disorders: Brief review

Workers experience recurrent episodes of fatigue during physical work that requires effort from the upper extremity. Although the etiology of fatigue is not well understood, the general agreement is that muscular work causes abnormal increases in intramuscular pressure, thus impairing local tissue perfusion causing ischemia and fatigue. Low-force contractions result in impaired oxidative metabolism, causing muscle fatigue that may be a precursor to muscle disorders. There is evidence that near-infrared spectroscopy (NIRS)-derived signals can be used to evaluate oxidative metabolism in working muscles. Muscle oxygenation status during upper extremity work could help provide insight into the pathophysiological mechanisms behind work-related muscle fatigue. This paper reviews the role of NIRS-derived measures in characterizing muscle performance of the upper body in the workplace and in evaluating fatigue and injury prevention. Relevance to industry In industry, there is a need for methodologies that provide reliable physiological measures under field conditions. NIRS offers portability and ease of operation, and provides an estimate of muscular metabolism under conditions where invasive methods are not possible.

A Predictive Model for Fatigue and Its Etiologic Associations in Primary Biliary Cirrhosis

Excessive day-time somnolence and autonomic dysfunction are biological processes prevalent in Primary Biliary Cirrhosis (PBC) that associate with fatigue. Here we explore how these biological associates inter-relate, and their cumulative impact upon typical clinical cohorts. A predictive model for daytime hypersomnolence (Epworth Sleepiness Scale (ESS)) and autonomic dysfunction (Orthostatic Grading Scale (OGS)) was developed in a derivation cohort (n=124) and subsequently validated in a second cohort (n=114). Subjects also completed the disease specific quality of life tool, the PBC-40. A composite predictive criterion (presence of either ESS > or =10 or OGS > or =4) for the presence of fatigue in PBC patients had a sensitivity of 0.71 (95% confidence intervals 0.59-0.81) and specificity 0.8 (0.67-0.9) (positive predictive value (PV); 0.84 (0.72-0.92), negative PV; 0.66 (0.53-0.78) for moderate or severe fatigue). Ninety-seven percent of severely fatigued patients (0% of non-fatigued) met the aetiology predictive criterion (chi(2) 49.6, P<.0001). Expression of both significant daytime somnolence and autonomic dysfunction was not associated with more severe fatigue, suggesting that there is a threshold effect for fatigue in PBC. When applied to a second independent cohort, the composite criterion retained strongly significant predictive value for fatigue. A significant proportion of fatigue in PBC associates with one or both of autonomic dysfunction (OGS > or =4) and sleep disturbance (ESS > or =10). Those meeting both ESS and OGS criteria were not more severe fatigued than those meeting the diagnostic criterion for either OGS or ESS alone. A threshold effect for fatigue has implications for potential therapeutic interventions.

The brain and fatigue: New opportunities for nutritional interventions?

It is clear that the cause of fatigue is complex, influenced by events occurring in both the periphery and the central nervous system. Work conducted over the last 20 years has focused on the role of brain serotonin and catecholamines in the development of fatigue, and the possibility that manipulation of neurotransmitter precursors may delay the onset of fatigue. While there is some evidence that branched-chain amino acid and tyrosine ingestion can influence perceived exertion and some measures of mental performance, the results of several apparently well-controlled laboratory studies have not demonstrated a positive effect on exercise capacity or performance under temperate conditions. As football is highly reliant upon the successful execution of motor skills and tactics, the possibility that amino acid ingestion may help to attenuate a loss in cognitive function during the later stages of a game would be desirable, even in the absence of no apparent benefit to physical performance. There are several reports of enhanced performance of high-intensity intermittent exercise with carbohydrate ingestion, but at present it is difficult to separate the peripheral effects from any potential impact on the central nervous system. The possibility that changes in central neurotransmission play a role in the aetiology of fatigue when exercise is performed in high ambient temperatures has recently been examined, although the significance of this in relation to the pattern of activity associated with football has yet to be determined.

Lactic acid accumulation is an advantage/disadvantage during muscle activity

Lactic acid accumulation is an advantage/disadvantage during muscle activity