Fatigue symptoms relate to systemic inflammation in patients with type 2 diabetes

The relationship between self-perceived fatigue, muscle endurance, and circulating markers of inflammation in participants of the Copenhagen aging and Midlife Biobank (CAMB)

BACKGROUND

Fatigue, low muscle endurance, muscle weakness and low-grade inflammation are strongly related to frailty at higher age. When signs of self-perceived fatigue and low muscle endurance are interrelated with low-grade inflammation at midlife, they might be used as early markers for frailty. This study investigated whether the interrelationships among self-perceived fatigue, muscle endurance and inflammation can be observed at midlife.

METHODS

A total of 965 participants of the Copenhagen Aging and Midlife Biobank (aged 52 ± 4 years, 536 males, 426 females) were assessed for self-perceived fatigue (20-item multidimensional fatigue inventory), muscle endurance (grip work), circulating markers of inflammation (hsCRP, IL-6, IL-10, TNF-alpha and IFN-γ), daily physical activity (PAS-2), body composition (%body fat assessed by bio-impedance) and self-reported health status. Participants were categorised (correcting for age and gender) according to high fatigue and/or low muscle endurance, differences in inflammatory profile between fatigue categories were assessed by ANCOVA (corrected for PAS-2, %body fat and presence of inflammatory conditions).

RESULTS

Overall, muscle endurance, fatigue and inflammatory markers were significantly interrelated. Higher levels of hsCRP (p < 0.001), IL-6 (p < 0.001), IL-10 (p = 0.035) and TNF-alpha (p = 0.028) were observed in participants presenting both low muscle endurance and high fatigue. IFN-γ was highest in those with high fatigue but normal muscle endurance (p = 0.015).

CONCLUSIONS

Middle-aged participants with higher fatigue in combination with low muscle endurance show higher levels of inflammation, independently from physical activity, body fat and inflammatory pathology. The underlying mechanisms should be identified and future studies should also investigate whether these individuals show early signs of reduced physiological reserve capacity, which in later life come to full expression by means of frailty.

Inflammatory Markers and Fatigue in Individuals With Moderate to Severe Chronic Obstructive Pulmonary Disease

BACKGROUND

Fatigue, a prevalent complex symptom among patients with chronic obstructive pulmonary disease (COPD), is considered an important clinical indicator of disease severity. However, the underlying mechanisms of COPD-related fatigue are not fully understood.

OBJECTIVES

This analysis explored the relationships between peripheral inflammatory markers and COPD-related fatigue in people with moderate to severe COPD.

METHODS

This is a secondary analysis of a longitudinal observational study of individuals with COPD examining the biological causes and functional consequences of depression. The data used in this study were collected at baseline. Systemic inflammation markers included C-reactive protein (CRP) and three pro-inflammatory cytokines consisting of interleukin-6 (IL-6), IL-8, and tumor necrosis factor-α. COPD-related fatigue was self-reported using the Chronic Respiratory Questionnaire. Covariates included age; gender; smoking status; disease severity; symptoms of depression, anxiety, and pain; and social support. Multivariable linear regression analyses were conducted.

RESULTS

The sample included 300 adults living with COPD; 80% were male, and the average age was 67.6 years. Modest correlations were found between two systemic inflammatory markers (CRP and IL-8) and COPD-related fatigue. CRP was the only inflammatory marker significantly associated with fatigue symptoms after adjusting for covariates in multivariable analyses. Depression, pain, and education level were also significant predictors of COPD-related fatigue.

DISCUSSION

The findings suggest that altered immune response based on CRP may contribute to COPD-related fatigue. Management of depression and pain may work as an effective treatment strategy for COPD-related fatigue. Further longitudinal studies with a broader range of inflammatory markers and multidimensional measures of fatigue symptoms are warranted.

Fatigue following type 2 diabetes: Psychometric testing of the Indonesian version of the multidimensional fatigue Inventory-20 and unmet fatigue-related needs

Patients with type 2 diabetes mellitus (T2DM) often experience fatigue. The Multidimensional Fatigue Inventory (MFI-20) is a valid tool for evaluating fatigue; however, its psychometric properties have not been examined in Indonesian-speaking patients with T2DM. This study assessed the psychometric properties of the Indonesian version of the Multidimensional Fatigue Inventory-20 (IMFI-20) in patients with T2DM and investigated fatigue in a health-care setting. A cross-sectional design was adopted. Two hundred patients with T2DM were interviewed in clinics. Five self-structured measures were used to assess the frequency and duration of fatigue and the health-care utilization of patients with fatigue. Cronbach's alpha and intraclass correlation (ICC) were used to evaluate the internal consistency and test-retest reliability of the Indonesian version of the MFI-20 (IMFI-20). The criterion, convergent, and known-group validity of the IMFI-20 were also examined, and its underlying structure was determined using explanatory factor analysis. The STROBE checklist was used. The results revealed that approximately half of the patients experienced fatigue. Among those with fatigue, 62% reported that their fatigue was rarely or never treated by their physicians. The IMFI-20 exhibited satisfactory model fit, excellent internal consistency (Cronbach's alpha of 0.92), and test-retest ICC of 0.93. The IMFI-20 was significantly associated with the Functional Assessment of Chronic Illness Therapy-Fatigue, Beck Depression Inventory-Second Edition, and Pittsburgh Sleep Quality Index (r = 0.705, 0.670, and 0.581, respectively). The IMFI-20 exhibited known-group validity for unfavorable sleep quality and HbA1C ≥ 6.5%. Our findings suggest that patients with T2DM who experience fatigue are often overlooked by health-care providers, and that the IMFI-20, which exhibits excellent psychometric properties, can be adopted by studies that use fatigue as an endpoint in Indonesian-speaking populations.

Vitality, mental health and role-physical mediate the influence of coping on depressive symptoms and self-efficacy in patients with non-alcoholic fatty liver disease: A cross-sectional study

OBJECTIVE

Our aim was to determine whether the association between active coping and depressive symptoms in patients with non-alcoholic fatty liver disease (NAFLD) was mediated by vitality, and whether diabetes and obesity could impact on this relationship. We also wanted to find out whether mental health and role-physical modulated the relationship between passive/avoidance coping and self-efficacy, and the role of liver fibrosis.

METHODS

Depressive symptoms (BDI-II), self-efficacy (GSE), coping (COPE-28) and quality of life (SF-12) were evaluated in 509 biopsy-proven NAFLD patients in this cross-sectional study. Mediation and moderated mediation models were conducted using the SPSS PROCESS v3.5 macro.

RESULTS

Vitality mediated the relationship between active coping and depressive symptoms (-2.254, CI = -2.792 to -1.765), with diabetes (-0.043, p = 0.017) and body mass index (BMI) (-0.005, p = 0.009) moderating the association. In addition, mental health (-6.435, CI = -8.399 to -4.542) and role-physical (-1.137, CI = -2.141 to -0.315) mediated the relationship between passive/avoidance coping and self-efficacy, with fibrosis stage (0.367, p < 0.001) moderating this association. Specifically, the presence of diabetes and significant fibrosis, and a higher BMI, were associated with greater negative impact on participant depressive symptoms or self-efficacy.

CONCLUSION

A maladaptive coping style was associated with poorer vitality, mental health and role-physical in NAFLD patients, which along with the presence of metabolic comorbidity (diabetes and obesity) and significant fibrosis predicted more depressive symptoms or poorer self-efficacy in these patients. These results suggested incorporating emotional and cognitive evaluation and treatment in patients with NAFLD.

Remote sampling of biomarkers of inflammation with linked patient generated health data in patients with rheumatic and musculoskeletal diseases: an Ecological Momentary Assessment feasibility study

Background

People with rheumatic diseases experience troublesome fluctuations in fatigue. Debated causes include pain, mood and inflammation. To determine the relationships between these potential causes, serial assessments are required but are methodologically challenging. This mobile health (mHealth) study explored the viability of using a smartphone app to collect patient-reported symptoms with contemporaneous Dried Blood Spot Sampling (DBSS) for inflammation.

Methods

Over 30 days, thirty-eight participants (12 RA, 13 OA, and 13 FM) used uMotif, a smartphone app, to report fatigue, pain and mood, on 5-point ordinal scales, twice daily. Daily DBSS, from which C-reactive Protein (CRP) values were extracted, were completed on days 1–7, 14 and 30. Participant engagement was determined based on frequency of data entry and ability to calculate within- and between-day symptom changes. DBSS feasibility and engagement was determined based on the proportion of samples returned and usable for extraction, and the number of days between which between-day changes in CRP which could be calculated (days 1–7).

Results

Fatigue was reported at least once on 1085/1140 days (95.2%). Approximately 65% of within- and between-day fatigue changes could be calculated. Rates were similar for pain and mood. A total of 287/342 (83.9%) DBSS, were returned, and all samples were viable for CRP extraction. Fatigue, pain and mood varied considerably, but clinically meaningful (≥ 5 mg/L) CRP changes were uncommon.

Conclusions

Embedding DBSS in mHealth studies will enable researchers to obtain serial symptom assessments with matched biological samples. This provides exciting opportunities to address hitherto unanswerable questions, such as elucidating the mechanisms of fatigue fluctuations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05723-w.

The Link Between Energy-Related Sensations and Metabolism: Implications for Treating Fatigue

Energy-related sensations include sensation of energy and fatigue as well as subjective energizability and fatigability. First, we introduce interdisciplinary useful definitions of all constructs and review findings regarding the question of whether sensations of fatigue and energy are two separate constructs or two ends of a single dimension. Second, we describe different components of the bodily energy metabolism system (e.g., mitochondria; autonomic nervous system). Third, we review the link between sensation of fatigue and different components of energy metabolism. Finally, we present an overview of different treatments shown to affect both energy-related sensations and metabolism before outlining future research perspectives.

Coping with the Experience of Bad Sleep and Fatigue Associated with the Nursing Clinical Practicum

Nursing students experience anxiety during clinical practicum, which may interfere with their learning of clinical practice. This study explored the practicum anxiety symptom experience of clinical nursing students. The methodology was mixed research design consist of questionnaire and a qualitative research design following a grounded theory approach. Research data were gathered via theoretical sampling from 37 female college nursing students practicing in a Central Taiwan hospital and analyzed using the content analysis method. The mean age of the subjects was 20.7 ± 1.35 years old. The practicum-related anxiety symptom experience was made up of core dimensions associated with the nursing clinical practicum, such as bad sleep and fatigue, and covered six themes. Students first encountered anxiety-inducing situations in the clinical setting, and then they began coping through self-adaptation and teachers' help. In cases of coping failure, students began to have a bad sleep in the night and then felt tired and fatigued all day. These themes became a repeating cycle during the clinical practicum. This conceptual model shows that students experienced bad sleep and fatigue as a result of anxiety symptoms during the clinical practicum. Bad sleep and fatigue are critical anxiety symptoms for nursing students in clinical practice. Nursing teachers should pay attention to bad sleep and fatigue in nursing students and help students to improve their mental and physical health.

Prevalence and risk factors of fatigue in type 1 and type 2 diabetes: A systematic review and meta-analysis

PURPOSE

This meta-analysis was conducted to determine the prevalence and risk factors of fatigue in type 1 and type 2 diabetes mellitus (DM).

METHODS

Observational studies reporting the prevalence and risk factors of fatigue in type 1 or 2 DM were systematically searched for in PubMed, Embase, CINAHL Plus, Cochrane Trial, and ProQuest Dissertation and Theses databases. Data were extracted by two independent reviewers. A random-effect model was used for data analysis.

FINDINGS

We included 19 studies involving 7131 patients with type 1 DM and 32 studies involving 34,994 patients with type 2 DM in the study. The pooled prevalence of fatigue in type 1 and type 2 DM was 44% and 50%, respectively. The Asia-Pacific region (e.g., Japan and Australia), South America, and Africa lacked reports regarding fatigue prevalence in type 1 DM, and North Asia and Southeast Asia lacked reports of fatigue prevalence in type 2 DM. Depression and physical activity were the only two variables significantly correlated with fatigue in both type 1 and type 2 DM (all p < 0.05).

CONCLUSIONS

Approximately half of the patients with type 1 or type 2 DM experienced fatigue, with the prevalence of 44% and 50%, respectively. Our findings regarding its risk factors can provide an evidence-based approach for managing fatigue in DM patients.

CLINICAL RELEVANCE

This meta-analysis emphasizes the importance of fatigue management in patients with type 1 and type 2 DM. Most significantly, our results on risk factors related to fatigue in diabetes can contribute to the development of evidence-based strategies for managing fatigue in individuals with DM.

Exploring the relationship between fatigue and circulating levels of the pro-inflammatory biomarkers interleukin-6 and C-reactive protein in the chronic stage of stroke recovery: A cross-sectional study

Background

The precise mechanisms underlying the aetiology of post-stroke fatigue remain poorly understood. Inflammation has been associated with clinically significant fatigue across a number of neurological disorders; however, at present there is a lack of evidence regarding the association of fatigue and inflammation in the chronic phase of stroke recovery.

Aims

The aim of this study was to examine fatigue in a cohort of stroke survivors in the chronic phase of stroke, compared with matched controls, and to explore associations between the pro-inflammatory cytokine interleukin-6, high-sensitivity C-reactive Protein and fatigue.

Methods

We performed an exploratory cross-sectional study of 70 people in the chronic phase of stroke recovery, and 70 age matched controls. Fatigue was assessed using the Fatigue Assessment Scale. Interleukin-6 was measured in serum using a commercially available enzyme immunoassay kit. Both outcome measures were assessed contemporaneously.

Results

Clinically significant fatigue, defined as a score ≥24 on the Fatigue Assessment Scale, was reported by 60% of stroke survivors, and 15.7% of controls. The odds of experiencing clinically significant fatigue was 8.04 times higher among stroke survivors compared to control participants (odds ratio 8.045; 95% CI: 3.608, 17.939; P ​< ​0.001). The fatigue score was significantly correlated with the level of both interleukin-6 and high-sensitivity c-reactive protein, however once entered into a linear regression model with cardiovascular covariables, this relationship was no longer statistically significant.

Conclusions

This study shows that fatigue may be associated with systemic inflammation in the chronic phase of stroke. The pathological mechanisms underlying post-stroke fatigue and its clinical implications require further study.

An integrative review of fatigue in adults with type 2 diabetes mellitus: Implications for self-management and quality of life

AIMS AND OBJECTIVES

To synthesise empirical studies on factors related to fatigue and its impact on diabetes self-management (DSM) and quality of life (QOL) in adults with type 2 diabetes mellitus (T2DM).

BACKGROUND

Fatigue is commonly reported in people with T2DM, a chronic condition that is highly prevalent worldwide. However, a holistic understanding of the consequences and factors related to fatigue in adults with T2DM is not well synthesised.

DESIGN

This integrative review used Whittemore and Knafl's methodology and was reported according to the Preferred Reporting for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist.

METHODS

The theory of unpleasant symptoms (TOUS) was used as a conceptual model to guide the review. The PubMed, PsychINFO and CINAHL databases were searched to identify studies that recruited adults with T2DM, were peer-reviewed, written in English and investigated fatigue as a primary or secondary outcome. Two investigators independently appraised the quality of the studies and extracted the data.

RESULTS

Twenty-nine articles met the inclusion criteria: 23 observational studies, two randomised controlled trials, one quasi-experimental study and three qualitative studies. All articles were of high quality. Physiological (e.g. T2DM duration, complications and inflammatory biomarkers), psychological (e.g. diabetes distress, depression and sleep quality) and situational factors (e.g. race/ethnicity, education and social support) were related to fatigue. Studies reported fatigue as a barrier to physical activity, healthy eating behaviours and the physical aspect of QOL.

CONCLUSIONS

Multiple factors are related to fatigue in adults with T2DM. Gaps in the literature include the multiple dimensions of fatigue, the effectiveness of interventions to alleviate fatigue and fatigue experiences in under-represented populations.

RELEVANCE TO CLINICAL PRACTICE

This integrative review supports the complex origin of fatigue and its impact on adults with T2DM. Nurses should evaluate modifiable factors related to fatigue and provide support to help improve DSM and QOL in this population.

Contributing factors of fatigue in patients with type 2 diabetes: A systematic review

Remarkable evidence supports the link between type 2 diabetes (T2DM) and fatigue. However, a unifying recommendation to identify and prevent fatigue or to prevent its clinical consequences in T2DM is not available at present. Therefore, this study aimed to conduct a systematic review to summarize the definition, measurement tools, and contributing factors of fatigue in T2DM. Nine articles were included for analysis, and results showed that T2DM fatigue was associated with five major factors, including sociodemographic factors, clinical disease factors, inflammatory factors, psychological factors, and behavior and lifestyle. The contributing factors of T2DM fatigue are reviewed, and clinical benefits provide a theoretical basis for further clinical intervention to prevent the occurrence of fatigue and improve the patient's treatment compliance and self-management ability and may be beneficial to their quality of life.

The Impact of Obesity on Microglial Function: Immune, Metabolic and Endocrine Perspectives

Increased life expectancy in combination with modern life style and high prevalence of obesity are important risk factors for development of neurodegenerative diseases. Neuroinflammation is a feature of neurodegenerative diseases, and microglia, the innate immune cells of the brain, are central players in it. The present review discusses the effects of obesity, chronic peripheral inflammation and obesity-associated metabolic and endocrine perturbations, including insulin resistance, dyslipidemia and increased glucocorticoid levels, on microglial function.

The relationship between type 2 diabetes mellitus with cognitive functions

Background

Type 2 diabetes mellitus (T2DM) has been associated with impairment of cognitive functions. Since the majority of patients with diabetes in the Saudi population are between the ages of 40 and 69 years, it is crucial to ascertain whether the control of blood glucose level negatively correlates with the level of cognitive function scores similar to the way it correlates in those who are not controlling their blood glucose level with medications.

Aims

To assess cognitive functions in patients with T2DM and examine the effect of glycemic control on cognitive functions impairment in Saudi adults with T2DM.

Methods and material

Seventy-nine patients with T2DM underwent cognitive assessment testing using the Cambridge neuropsychological test automated battery (CANTAB), Mini-Mental State Examination (MMSE), and Fatigue severity scale. Their cognitive function scores were then correlated with their blood glucose levels, duration of diabetes, and levels of education. Poor glycemic control was defined as glycated hemoglobin levels more than 7.5. We excluded patients with depression or neurocognitive disorders as well as those over 75 years of age.

Results

Attention switching task (AST) total latency (P = 0.003), AST congruent score (P = 0.002), AST incongruent score (P = 0.003), AST block 3 (p = 0.004), and AST Block 7 (p = 0.006) were significantly higher in poorly-controlled DM. The intra-extra dimensional set shift (IED) total errors were significantly higher in poorly-controlled patients (p = 0.023). The difference in IED stages completed (p = 0.716) and spatial span (SSP) (p = 0.782) were not significant between the two groups. The mini-mental state exam (p = 0.336) and the fatigue severity scale (P = 0.167) did not show any statistical significance between good and poor control of T2DM. There was a significant positive correlation between the duration of T2DM and AST latencies for AST total latency, AST congruent score, and AST incongruent score.

Conclusions

Patients with T2DM have a statistically significant association between their cognitive functions and their glycemic control. Patients with uncontrolled T2DM showed decreased cognitive scores. Moreover, worsened cognitive scores were associated with longer disease duration.

Factors associated with fatigue in hip and/or knee osteoarthritis: a systematic review and best evidence synthesis

Objective

The aim was systematically to identify and evaluate factors related to fatigue in individuals with hip and/or knee OA.

Methods

A systematic literature search was conducted using AMED, CINAHL, MEDLINE, ProQuest and Web of Science Core Collections databases. Inclusion criteria comprised cross-sectional, case–control or longitudinal studies on patients with a diagnosis of hip and/or knee OA that included self-reported fatigue measures. Study quality was assessed using the National Heart, Lung and Blood Institute quality appraisal tool, and factors were synthesized within a bio-behavioural framework. Study designs and quality were combined to determine current evidence levels using best evidence synthesis grading. The full review protocol is available from PROSPERO (PROSPERO 2019: CRD42019138571).

Results

Twenty-four studies were included, of which 19 were high, 4 moderate and 1 low quality. There was strong evidence of an association between poor self-reported physical function and high depressive symptoms with higher fatigue. Moderate evidence of an association was found between severe pain, high numbers of co-morbidities and low physical activity levels with higher fatigue. There was moderate or limited evidence of no association between most sociodemographic factors and radiographic OA severity with fatigue.

Conclusion

Targets for fatigue management might include improving physical function, reducing depressive symptoms, pain and co-morbidities, and increasing physical activity levels. There is a need for more rigorous longitudinal studies to understand the causal effect of fatigue determinants within the hip and knee OA populations.

Fatigue in irritable bowel syndrome is associated with plasma levels of TNF-α and mesocorticolimbic connectivity

Irritable bowel syndrome (IBS) is a symptom-based disorder of gut-brain interactions generating abdominal pain. It is also associated with a vulnerability to develop extraintestinal symptoms, with fatigue often reported as one of the most disturbing. Fatigue is related to brain function and inflammation in several disorders, however, the mechanisms of such relations in IBS remain elusive. This study aimed to elucidate fatigue and its association with a resting state network of mesocorticolimbic regions of known importance in fatigue, and to explore the possible role of circulating TNF-α levels in IBS and healthy controls (HC). Resting state functional magnetic resonance imaging (fMRI) was conducted in 88 IBS patients and 47 HC of similar age and gender to investigate functional connectivity between mesocorticolimbic regions. Further, fatigue impact on daily life and plasma levels of the proinflammatory cytokine tumor necrosis factor-α (TNF-α), of known relevance to immune activation in IBS, were also measured. The selected mesocorticolimbic regions indeed formed a functionally connected network in all participants. The nucleus accumbens (NAc), in particular, exhibited functional connectivity to all other regions of interest. In IBS, fatigue impact on daily life was negatively correlated with the connectivity between NAc and dorsolateral prefrontal cortex bilaterally (left p = 0.019; right p = 0.038, corrected for multiple comparisons), while in HC, fatigue impact on daily life was positively correlated to the connectivity between the right NAc and anterior middle insula in both hemispheres (left p = 0.009; right p = 0.011). We found significantly higher levels of TNF-α in IBS patients compared to HC (p = 0.001) as well as a positive correlation between TNF-α and fatigue impact on daily life in IBS patients (rho = 0.25, p = 0.02) but not in HC (rho = -0.13, p = 0.37). There was no association between functional connectivity in the mesocorticolimbic network and plasma levels of TNF-α in either group In summary, this novel multimodal study provides the first evidence that the vulnerability to fatigue in IBS is associated with connectivity within a mesocorticolimbic network as well as immune activation. These findings warrant further investigation, both peripherally and potentially with measurements of central immune activation as well.

Predictors of fatigue in rheumatoid arthritis

People with RA commonly experience fatigue. Fatigue is a key contributor to increased clinical care costs, primary care consultations and employment loss. Despite this, our understanding of the prognostic of factors of poor fatigue outcomes is lacking and fatigue is poorly managed. Examining longitudinal predictors of fatigue can identify both individuals ‘at risk’ of poor prognosis, and candidate mechanisms that are worthy of greater inspection. This review discusses the factors most commonly investigated as being implicated in the prognosis of RA fatigue. The available data appears to implicate generic factors such as pain, mental health, disability and sleep as consistent predictors of fatigue outcome, while the role of disease activity and inflammation seems less clear. However, the existing data are not without methodological limitations and there have been no specific studies primarily designed to investigate the inflammatory biomarkers of fatigue. Future studies are required to more comprehensively and robustly determine the mechanisms of fatigue.

Real-Time Associations Between Glucose Levels and Fatigue in Type 2 Diabetes: Sex and Time Effects

OBJECTIVE

Fatigue is a pervasive and serious complaint among aging adults with type 2 diabetes. Anecdotally, hyperglycemia was thought to cause fatigue, but prior cross-sectional analyses failed to find any relationship between glucose levels and fatigue. However, study methodology may have caused this relationship to be missed. Our aim was to use concurrent and continuous data across 5 days to examine real-time momentary relationships between glucose and fatigue levels by week, day, and time of day. Additionally, we explored how these relationships differed by sex.

METHOD

Participants (N = 54, 51% male, 54% non-White) wore continuous glucose monitors and wrist actigraphy into which they inputted fatigue ratings 6-8 times daily during waking hours across 5 days. Generalized estimation equation models were used to explore the relationship between glucose and fatigue when averaged by week, day, and time of day. Differences by sex were also explored.

RESULTS

HbA1c and baseline and real-time fatigue were higher in women than in men. Baseline HbA1c and self-reported general fatigue were unrelated. Fatigue levels averaged by day and time of day were higher in women than in men (p < .05). Glucose and fatigue were significantly related at all levels of data (weekly, daily, and time of day) in women but not men.

CONCLUSIONS

Our findings suggest that, when measured concurrently, glucose excursions may affect fatigue levels in women.

HIV infection drives IgM and IgG3 subclass bias in Plasmodium falciparum-specific and total immunoglobulin concentration in Western Kenya

Background

HIV infection is associated with more frequent and severe episodes of malaria and may be the result of altered malaria-specific B cell responses. However, it is poorly understood how HIV and the associated lymphopenia and immune activation affect malaria-specific antibody responses.

Methods

HIV infected and uninfected adults were recruited from Bondo subcounty hospital in Western Kenya at the time of HIV testing (antiretroviral and co-trimoxazole prophylaxis naïve). Total and Plasmodium falciparum apical membrane antigen-1 (AMA1) and glutamate rich protein-R0 (GLURP-R0) specific IgM, IgG and IgG subclass concentrations was measured in 129 and 52 of recruited HIV-infected and uninfected individuals, respectively. In addition, HIV-1 viral load (VL), CD4⁺ T cell count, and C-reactive protein (CRP) concentration was quantified in study participants. Antibody levels were compared based on HIV status and the associations of antibody concentration with HIV-1 VL, CD4⁺ count, and CRP levels was measured using Spearman correlation testing.

Results

Among study participants, concentrations of IgM, IgG1 and IgG3 antibodies to AMA1 and GLURP-R0 were higher in HIV infected individuals compared to uninfected individuals (all p < 0.001). The IgG3 to IgG1 ratio to both AMA1 and GLURP-R0 was also significantly higher in HIV-infected individuals (p = 0.02). In HIV-infected participants, HIV-1 VL and CRP were weakly correlated with AMA1 and GLURP-R0 specific IgM and IgG1 concentrations and total (not antigen specific) IgM, IgG, IgG1, and IgG3 concentrations (all p < 0.05), suggesting that these changes are related in part to viral load and inflammation.

Conclusions

Overall, HIV infection leads to a total and malaria antigen-specific immunoglobulin production bias towards higher levels of IgM, IgG1, and IgG3, and HIV-1 viraemia and systemic inflammation are weakly correlated with these changes. Further assessments of antibody affinity and function and correlation with risk of clinical malaria, will help to better define the effects of HIV infection on clinical and biological immunity to malaria.

Association of Systemic Inflammation and Fatigue in Osteoarthritis: 2007-2010 National Health and Nutrition Examination Survey

BACKGROUND/PURPOSE

Mechanistic insight into osteoarthritis fatigue is needed as clinical management of this condition is nonspecific. Systemic inflammation is associated with fatigue in other chronic diseases. The purpose of this study was to explore the relationship between systemic inflammation and fatigue in osteoarthritis, while controlling for covariates.

METHOD

This secondary analysis with a cross-sectional, multiyear retrospective design used data from the 2007-2010 National Health and Nutrition Examination Survey. Adults with self-reported osteoarthritis who participated in an examination at a mobile center and had no comorbidities associated with fatigue or systemic inflammation were included (n = 296). Complex sample analysis, independent samples t tests, and χ² tests of independence were used to explore differences between nonfatigued and fatigued adults with osteoarthritis. Adjusted hierarchical logistic regression models were used to calculate odds of fatigue as a function of two systemic inflammatory markers, C-reactive protein (CRP), and white blood cell (WBC) count.

RESULTS

Fatigued adults with osteoarthritis had significantly higher CRP levels and WBC counts compared to nonfatigued adults with osteoarthritis. In adjusted logistic regression models, increased CRP was associated with higher odds of fatigue when controlling for age, days affected by pain, depressive symptoms, sleep quantity, and body mass index (Odds ratio [OR] = 3.38, 95% CI [1.18, 9.69]). WBC count was not associated with higher odds of fatigue when controlling for these variables (OR = 1.10, 95% CI [0.92, 1.32]).

CONCLUSION

Systemic inflammation may have a relationship with fatigue in osteoarthritis. Future work is necessary to replicate these findings in more robust studies.

Scalp hair cortisol and testosterone levels in patients with sarcoidosis

Background

Patients with sarcoidosis often experience fatigue and psychological distress, but little is known about the etiology of these conditions. While serum and saliva steroid hormones are used to monitor acute steroid levels, scalp hair analysis is a relatively new method enabling measurement of long-term steroid levels, including hair cortisol reflecting chronic stress. We investigated whether scalp hair cortisol and testosterone levels differ between sarcoidosis patients both with and without fatigue and general population controls. Additionally, we studied if these hormones could serve as objective biomarkers for psychological distress in patients with sarcoidosis.

Methods

We measured hair steroid levels using liquid chromatography–tandem mass spectrometry in glucocorticoid naïve sarcoidosis patients. Patients completed the Perceived Stress Scale, Fatigue Assessment Scale, Hospital Anxiety and Depression Scale and Short Form 36 (SF-36). Hair steroid levels from 293 participants of the population-based Lifelines cohort study served as controls.

Results

Thirty-two patients (14 males) were included. Hair cortisol, but not testosterone, concentrations were significantly higher in patients with sarcoidosis than in general population controls (mean 6.6 versus 2.7 pg/mg, p<0.001). No differences were found in hair cortisol and testosterone levels between fatigued and non-fatigued patients with sarcoidosis. Hair cortisol of sarcoidosis patients correlated significantly with anxiety (r = 0.47, p = 0.01), depression (r = 0.46, p = 0.01), and SF-36 mental domain (r = -0.38, p = 0.03), but not with fatigue.

Conclusions

Patients with sarcoidosis have chronically higher levels of the stress hormone cortisol than the normal population, while testosterone levels in hair did not differ. Hair cortisol levels were positively related to subjective measures of psychological distress, but not to fatigue. Our study shows that hair cortisol is a promising non-invasive biomarker for psychological distress in patients with sarcoidosis.

Trial registration

ClinicalTrials.gov: NCT03108547. Registered 31 March 2017, retrospectively registered.

A review and synthesis of correlates of fatigue in osteoarthritis

Fatigue affects nearly half of all adults with osteoarthritis. Affected individuals report difficulty with daily functioning, requiring more time and rest during activities, feeling easily exhausted, and having to give up on social and volunteer activities known to improve quality of life. Because its etiology is poorly understood, clinical practice guidelines are unable to address management of fatigue in osteoarthritis. Elucidating a mechanism of osteoarthritis fatigue is a high priority, but few studies have identified key factors associated with fatigue in osteoarthritis. Thus, the purpose of this narrative literature review is to present the current evidence of known and potential correlates of fatigue in osteoarthritis, and synthesize our findings into a conceptual framework. The overarching goal of this work is to provide insight into areas of needed research and guide future work toward mechanistic insight of osteoarthritis fatigue. This knowledge could lead to novel nursing interventions for prevention, management, and treatment of fatigue among adults with osteoarthritis.

Collaborative Framework to Advance Symptom Science: An Intramural Perspective

PURPOSE

To describe the collaborative framework used by National Institute of Nursing Research (NINR) investigators to advance symptom science and to provide a research exemplar.

MODEL

The National Institutes of Health (NIH) Symptom Science Model (SSM) was developed to guide symptom science researchers to understand the molecular underpinnings of symptoms using innovative "omics" approaches. The process begins with a review of the literature to understand the state of the science of the symptoms of interest and is followed by cross-sectional, case-controlled, or longitudinal studies to identify potential biological correlates of these symptoms. The final steps include validation of these potential symptom biomarkers using multidisciplinary, collaborative, preclinical experiments, and proof-of-concept clinical trials.

RESEARCH EXEMPLAR

Using the NIH SSM as a guide, the identification of biologic correlates of symptoms using omics and bioinformatic strategies depends on determining the distinct phenotype of the symptoms of interest. The identified biologic correlates of these symptoms are then validated for their functional relevance using in vitro and ex vivo experiments, or through proof-of-concept clinical trials. NINR investigators observed that activation of specific receptors in neural networks can trigger inflammation-related fatigue development and predispose patients to develop chronicity of symptoms. Specifically targeting these neural receptors can reduce symptom intensity.

CONCLUSIONS

Through using the NIH SSM as a guide, NINR investigators quickly generate data and discoveries that significantly advance symptom science by simultaneously collaborating with multiple experts and core laboratories to identify more correlates and validate their functional relevance in order to further understand the biological underpinnings of the symptoms of interest.

CLINICAL RELEVANCE

The collaborative framework used by NINR investigators as guided by the NIH SSM identifies functionally relevant clinical markers that can explain the biological underpinnings of symptoms and can be targeted to optimize symptom management.

An effort expenditure perspective on cancer-related fatigue

While fatigue is the most common and debilitating side effect of cancer and cancer treatment it is still poorly understood, partly because it is usually characterized by patient-reported outcomes. As patient-reports are inherently subjective, behavioral correlates of the symptom of fatigue are needed to increase our understanding of the symptom. We focused on motivational effort expenditure as a crucial behavior in cancer-related fatigue, using a validated computerized task contrasting high effort/high reward and low effort/low reward choices under different probabilities of success. Effort expenditure-choices were analyzed in 47 cancer patients differing by their status; current evidence for disease (n = 17) or post-treatment survivors with no evidence for disease (n = 30). In addition, patient-reported fatigue, negative and positive affect, and biomarkers of inflammation were assessed. Patient-reported general and motivational fatigue, negative affect, and plasma concentrations of pro-inflammatory biomarkers were related to higher effort expenditure while positive affect was associated with lower effort expenditure. As all four measures interacted with patient status, exploratory models were computed for patients and survivors separately. These analyses indicated that the effects of fatigue and negative affect were predominantly seen in survivors. In patients still under or shortly post treatment, general fatigue, but not motivational fatigue, was associated with lower effort expenditure but only in the most favorable reward condition. Negative affect did not have an effect. Thus, the effects observed seemed primarily driven by cancer survivors in whom both fatigue and negative affect were associated with higher effort expenditure. These findings are tentatively interpreted to suggest that a tendency to invest more effort despite feelings of fatigue is a vulnerability for developing chronic fatigue. Inflammation and negative affect might contribute to fatigue in some survivors through this effort investment pathway.

Impaired mental health and low-grade inflammation among fatigued bereaved individuals

BACKGROUND

Fatigue is a common symptom in stressed individuals. Bereavement is a major life event that has been associated with impaired mental health. Little research has investigated the prevalence of fatigue and its inflammatory correlates in bereaved individuals.

OBJECTIVES

To assess fatigue prevalence and its relationship with mental health outcomes and markers of inflammation, as indexed by C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in bereaved individuals.

METHODS

Seventy-eight-bereaved adults were examined for fatigue (SF-36 energy/vitality scale), perceived stress (PSS), depression (CES-D), sleep quality (PSQI), pain (SF-36 pain scale), and general health (SF-36 general), and their serum levels of CRP, IL-6 and TNF-α were measured. Group differences between fatigued versus non-fatigued individuals were estimated using analysis of covariance (ANCOVA), with adjustment for body mass index (BMI).

RESULTS

Fatigued bereaved individuals (33%; SF-36 energy/vitality score 0-45) had significantly higher CRP levels (p < .05) as compared to non-fatigued bereaved individuals and reported higher levels of pain (p < .001), greater stress (p < .001), depression (p < .001), and sleeping problems (p < .001), as well as poorer social functioning (p < .001) and general health (p < .001) than those in the non-fatigued group. No group differences were found for IL-6 and TNF-α.

CONCLUSIONS

Fatigued bereaved individuals showed elevated systemic inflammation as measured by CRP in comparison to non-fatigued bereaved individuals. They were also more likely to report mental health problems that co-occur with fatigue in the context of immune activation. Continued research is needed to help clarify the involvement of inflammatory markers in the development of fatigue in a larger sample of bereaved adults.

Musculoskeletal Injuries Among Female Soldiers Working With Dogs

INTRODUCTION

Female soldiers serving in the Israeli Defense Forces canine unit may be at increased risk of overuse injuries related to working with military dogs. We hypothesized that this particular type of occupational exposure may lead to an increased strain of the upper extremity due to such non-physiologic motions as pulling the dog's strap or resisting the sudden pulling by the dog, and may result in an increased rate of overuse injuries.

MATERIALS AND METHODS

We compared incidence of overuse injuries in a retrospective cohort of female soldiers who served either in the military working dogs' unit (MWD), or in the light infantry battalions (Infantry) from 2005 to 2015. We compared injury incidence of both groups during two periods: 5 mo of basic training (neither worked with dogs) and 19 or more months of combat service. Incidence was calculated as number of diagnoses per person-months (rate ratios, RR); each diagnosis counted once per study subject. We used RR confidence intervals to compare incidence of injuries between groups.

RESULTS

There were 3,443 person-months in the MWD group and 194,590 person-months in the Infantry group. There was no difference in injury incidence between groups during the initial period of basic training. During the second period, MWDs had higher incidence of upper limb (RR = 1.45, p = 0.048) and hip (RR = 3.6, p < 0.0001) injuries. The association between service with dogs and upper limb injuries remained significant (RR = 1.09, p = 0.005) after adjusting for confounding variables in the multivariate regression analysis. Other independent predictors of the upper limb overuse injuries included each additional month of service (RR = 1.003, p = 0.008), Eastern European origin compared with Israeli-born recruits (RR = 0.97, p = 0.03), increased body weight in increments of 10 kg (RR = 1.008, p = 0.03), anemia (RR = 1.02, p = 0.02) and fatigue (RR = 1.05, p ≤ 0.0001).

CONCLUSIONS

We found that service in the MWD unit was associated with increased risk of upper limb injuries. Identification of the exact mechanism of injury and targeted interventions, as well as treatment of anemia and fatigue may lead to reduction of injuries in this unit.

Diabetes Fatigue Syndrome

In this editorial we propose a condition that we refer to as 'diabetes fatigue syndrome' (DFS), which is commonly encountered in clinical practice. We define DFS as a multifactorial syndrome of fatigue or easy fatigability that occurs in persons with diabetes. It may be caused by a variety of lifestyle, nutritional, medical, psychological, glycemia/diabetes-related, and endocrine and iatrogenic factors. The authors share clinical pearls which can help the diabetes healthcare provider diagnose DFS, identify its etiologic factors and manage the syndrome. The editorial highlights the need to focus on symptomatic well-being in diabetes, along with efforts to achieve numerical targets.

Age modification of the relationship between C-reactive protein and fatigue: findings from Understanding Society (UKHLS)

BACKGROUND

Systemic inflammation may play a role in the development of idiopathic fatigue, that is, fatigue not explained by infections or diagnosed chronic illness, but this relationship has never been investigated in community studies including the entire adult age span. We examine the association of the inflammatory marker C-reactive protein (CRP) and fatigue assessed annually in a 3-year outcome period for UK adults aged 16-98.

METHODS

Multilevel models were used to track fatigue 7, 19, and 31 months after CRP measurement, in 10 606 UK individuals. Models accounted for baseline fatigue, demographics, health conditions diagnosed at baseline and during follow-up, adiposity, and psychological distress. Sensitivity analyses considered factors including smoking, sub-clinical disease (blood pressure, anaemia, glycated haemoglobin), medications, ethnicity, and alcohol consumption.

RESULTS

Fatigue and CRP increased with age, and women had higher values than men. CRP was associated with future self-reported fatigue, but only for the oldest participants. Thus, in those aged 61-98 years, high CRP (>3 mg/L) independently predicted greater fatigue 7, 19, and 31 months after CRP measurement [odds ratio for new-onset fatigue after 7 months: 1.88, 95% confidence interval (CI) 1.21-2.92; 19 months: 2.25, CI 1.46-3.49; 31 months: 1.65, CI 1.07-2.54]. No significant longitudinal associations were seen for younger participants.

CONCLUSIONS

Our findings support previously described CRP-fatigue associations in older individuals. However, there are clear age modifications in these associations, which may reflect a contribution of unmeasured sub-clinical disease of limited relevance to younger individuals. Further work is necessary to clarify intervening processes linking CRP and fatigue in older individuals.

The High Costs of Low-Grade Inflammation: Persistent Fatigue as a Consequence of Reduced Cellular-Energy Availability and Non-adaptive Energy Expenditure

Chronic or persistent fatigue is a common, debilitating symptom of several diseases. Persistent fatigue has been associated with low-grade inflammation in several models of fatigue, including cancer-related fatigue and chronic fatigue syndrome. However, it is unclear how low-grade inflammation leads to the experience of fatigue. We here propose a model of an imbalance in energy availability and energy expenditure as a consequence of low-grade inflammation. In this narrative review, we discuss how chronic low-grade inflammation can lead to reduced cellular-energy availability. Low-grade inflammation induces a metabolic switch from energy-efficient oxidative phosphorylation to fast-acting, but less efficient, aerobic glycolytic energy production; increases reactive oxygen species; and reduces insulin sensitivity. These effects result in reduced glucose availability and, thereby, reduced cellular energy. In addition, emerging evidence suggests that chronic low-grade inflammation is associated with increased willingness to exert effort under specific circumstances. Circadian-rhythm changes and sleep disturbances might mediate the effects of inflammation on cellular-energy availability and non-adaptive energy expenditure. In the second part of the review, we present evidence for these metabolic pathways in models of persistent fatigue, focusing on chronic fatigue syndrome and cancer-related fatigue. Most evidence for reduced cellular-energy availability in relation to fatigue comes from studies on chronic fatigue syndrome. While the mechanistic evidence from the cancer-related fatigue literature is still limited, the sparse results point to reduced cellular-energy availability as well. There is also mounting evidence that behavioral-energy expenditure exceeds the reduced cellular-energy availability in patients with persistent fatigue. This suggests that an inability to adjust energy expenditure to available resources might be one mechanism underlying persistent fatigue.

Anti-interleukin-1 therapy has mild hypoglycaemic effect in type 2 diabetes

The aim of this study was to systematically evaluate the efficacy and safety of anti-interleukin-1 therapy for type 2 diabetes. A literature search of PubMed and Embase for available trials on anti-interleukin-1 therapy in type 2 diabetes was performed. The baseline characteristics, changes in HbA1c and other metabolic parameters, and adverse events were extracted from included randomized controlled trials (RCTs) and were analysed with Review Manager. Mean differences (MDs) and 95% confidence intervals (Cis) were calculated to measure differences in metabolic parameters. Odds ratio and 95% CIs were calculated for adverse event rates. Five RCTs were included in the current meta-analysis with 357 subjects undergoing anti-interleukin-1 therapy (IL-1 receptor antagonist or anti-IL-1beta antibody) and 221 controls who received placebo. The HbA1c decrement (%) of anti-interleukin-1 group was significantly higher than that of the placebo group (MD = 0.23; 95% CI, -0.39 to -0.07; P = .005). AUC of C-peptide was improved also (MD = 14.55; 95% CI, 1.81-27.28; P = .03) after anti-interleukin-1 intervention. There was no difference in the rate of adverse events (odds ratio,1.16; 95% CI, 0.90-1.49; P = .25) between 2 groups. Anti-interleukin-1 therapy has mild hypoglycaemic effect in type 2 diabetes.

Genetic contributions to self-reported tiredness

Self-reported tiredness and low energy, often called fatigue, are associated with poorer physical and mental health. Twin studies have indicated that this has a heritability between 6 and 50%. In the UK Biobank sample (N=108 976), we carried out a genome-wide association study (GWAS) of responses to the question, 'Over the last two weeks, how often have you felt tired or had little energy?' Univariate GCTA-GREML found that the proportion of variance explained by all common single-nucleotide polymorphisms for this tiredness question was 8.4% (s.e.=0.6%). GWAS identified one genome-wide significant hit (Affymetrix id 1:64178756_C_T; P=1.36 × 10-11). Linkage disequilibrium score regression and polygenic profile score analyses were used to test for shared genetic aetiology between tiredness and up to 29 physical and mental health traits from GWAS consortia. Significant genetic correlations were identified between tiredness and body mass index (BMI), C-reactive protein, high-density lipoprotein (HDL) cholesterol, forced expiratory volume, grip strength, HbA1c, longevity, obesity, self-rated health, smoking status, triglycerides, type 2 diabetes, waist-hip ratio, attention deficit hyperactivity disorder, bipolar disorder, major depressive disorder, neuroticism, schizophrenia and verbal-numerical reasoning (absolute rg effect sizes between 0.02 and 0.78). Significant associations were identified between tiredness phenotypic scores and polygenic profile scores for BMI, HDL cholesterol, low-density lipoprotein cholesterol, coronary artery disease, C-reactive protein, HbA1c, height, obesity, smoking status, triglycerides, type 2 diabetes, waist-hip ratio, childhood cognitive ability, neuroticism, bipolar disorder, major depressive disorder and schizophrenia (standardised β's had absolute values<0.03). These results suggest that tiredness is a partly heritable, heterogeneous and complex phenomenon that is phenotypically and genetically associated with affective, cognitive, personality and physiological processes.

Unemployment and inflammatory markers in England, Wales and Scotland, 1998-2012: Meta-analysis of results from 12 studies

INTRODUCTION

Unemployment represents for many affected individuals a substantial source of psychosocial stress, and is linked to both increased risk of morbidity and mortality and adverse health-related behaviours. Few studies have examined the association of unemployment with systemic inflammation, a plausible mediator of the associations of psychosocial stress and health, and results are mixed and context dependent. This study examines the association of unemployment with C-reactive protein (CRP) and fibrinogen, two markers of systemic inflammation.

METHODS

A random-effects meta-analysis was performed using a multilevel modelling approach, including 12 national UK surveys of working-age participants in which CRP and fibrinogen were measured between 1998 and 2012 (N=30,037 economically active participants). The moderating impact of participant age and UK country was explored.

RESULTS

CRP and fibrinogen were elevated in unemployed compared to employed participants; jobseekers were also more likely (Odds Ratio: 1.39, p<0.001) to have CRP levels corresponding to high cardiovascular risk (>3mg/L), after adjustment for age, gender, education, long-term illness, smoking, and body mass index. Associations were not explained by mental health. Associations peaked in middle-age, and were stronger in Scotland and Wales than in England.

CONCLUSIONS

Our study demonstrates that systemic inflammation is associated with an important but little-studied aspect of the social environment, as it is elevated in unemployed compared to employed survey participants. Modifications suggest the association of unemployment and inflammation is substantially influenced by contextual factors, and may be especially strong in Wales, where further investigation of this relationship is needed.

Role of Inflammation in Human Fatigue: Relevance of Multidimensional Assessments and Potential Neuronal Mechanisms

Fatigue is a highly disabling symptom in various medical conditions. While inflammation has been suggested as a potential contributor to the development of fatigue, underlying mechanisms remain poorly understood. In this review, we propose that a better assessment of central fatigue, taking into account its multidimensional features, could help elucidate the role and mechanisms of inflammation in fatigue development. A description of the features of central fatigue is provided, and the current evidence describing the association between inflammation and fatigue in various medical conditions is reviewed. Additionally, the effect of inflammation on specific neuronal processes that may be involved in distinct fatigue dimensions is described. We suggest that the multidimensional aspects of fatigue should be assessed in future studies of inflammation-induced fatigue and that this would benefit the development of effective therapeutic interventions.

Immune-to-Brain Communication Pathways in Inflammation-Associated Sickness and Depression

A growing body of evidence now highlights a key role for inflammation in mediating sickness behaviors and depression. Systemic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, and chronic liver disease have high comorbidity with depression. How the periphery communicates with the brain to mediate changes in neurotransmission and thereby behavior is not completely understood. Traditional routes of communication between the periphery and the brain involve neural and humoral pathways with TNFα, IL-1β, and IL-6 being the three main cytokines that have primarily been implicated in mediating signaling via these pathways. However, in recent years communication via peripheral immune-cell-to-brain and the gut-microbiota-to-brain routes have received increasing attention for their ability to modulate brain function. In this chapter we discuss periphery-to-brain communication pathways and their potential role in mediating inflammation-associated sickness behaviors and depression.

Inflammatory, endocrine and metabolic correlates of fatigue in obese children

Alterations in endocrine functions and low-grade systemic inflammation represent fundamental characteristics of obesity. These biological systems have been repeatedly linked to fatigue symptoms. The aim of the study was to assess the relationship between fatigue dimensions and metabolic/inflammatory markers in a sample of non-diabetic obese children. The possibility that inflammation-induced alterations in tryptophan metabolism relates to specific dimensions of fatigue was also investigated in a subsample of patients. The study was conducted in 41 obese children, median aged 12 [9-15] years, recruited in a pediatric tertiary center. Three dimensions of fatigue (e.g., general fatigue, sleep/rest, cognitive fatigue) were assessed using the Pediatric Quality of Life Inventory Multidimentional Fatigue Scale. In addition, a principal component analysis was performed to identify fatigue dimensions that were specific to the population under study. This analysis extracted five relevant dimensions corresponding respectively to concentration, energy, self-perceived cognitive efficiency, sleep/rest and motivation/anhedonia. Blood samples were collected for the measurement of inflammatory and metabolic markers, including high sensitivity C-reactive protein (hs-CRP), insulin, uricemia and glycaemia. Tryptophan, kynurenine and neopterin levels were also determined in a subsample of 17 patients. In the whole population under study, cognitive fatigue and reduced motivation/anhedonia were associated with BMI, independently of sex and age. The dimension of reduced motivation/anhedonia was associated with insulin resistance and inflammatory biomarkers. The association with insulin resistance persisted when the extent of fat mass (BMI-SDS) was taken into account. No association was found between tryptophan metabolism and specific dimensions of fatigue, but kynurenine and the kynurenine/tryptophan ratio correlated with insulin and HOMA-IR. These data indicate that insulin resistance in non diabetic obese children is associated with both cognitive fatigue and reduced motivation/anhedonia and with alterations in tryptophan metabolism. Further investigations are needed to determine whether inflammation-induced alterations in tryptophan metabolism is directly or indirectly implicated in insulin resistance and related fatigue.

Severe fatigue in type 1 diabetes: Exploring its course, predictors and relationship with HbA1c in a prospective study

AIMS

To prospectively identify the course of severe fatigue, its predictors and the relationship with HbA_1c in patients with type 1 diabetes.

METHODS

214 adult patients completed questionnaires on fatigue severity and fatigue-related factors at baseline. HbA_1c was retrieved from medical records. After 43months, fatigue severity and HbA_1c were reassessed in 194 patients. A logistic regression analysis was used to determine predictors of severe fatigue at follow-up with various cognitive-behavioral and clinical factors as potential predictors. The relationship between fatigue and HbA_1c was investigated in a sub-analysis by differentiating between patients with suboptimal glucose control [HbA_1c>7% (53mmol/mol)] and optimal glucose control [HbA_1c⩽7% (53mmol/mol)].

RESULTS

The prevalence of severe fatigue was 40% at baseline and 42% at follow-up. In three out of four severely fatigued patients at baseline (76%), severe fatigue persisted over time. More depressive symptoms, more pain, sleep disturbances, lower self-efficacy concerning fatigue, less confidence in diabetes self-care, more fatigue severity at baseline and more diabetes complications predicted severe fatigue at follow-up. Over time, HbA_1c at baseline was positively associated with fatigue severity at follow-up in both groups (suboptimal glucose control: r=.18, p<.05; optimal glucose control: r=.09, p<.05).

CONCLUSIONS

About three quarters of fatigued[corrected] patients with type 1 diabetes suffer from persistent fatigue. Aside from the number of diabetes complications, no clinical factors explained the persistence of fatigue. HbA_1c and fatigue were weakly associated in a sub-analysis. Since the strongest predictors of severe fatigue were cognitive-behavioral factors, behavioral interventions might be effective in decreasing fatigue.

Low-grade inflammation may moderate the effect of behavioral treatment for chronic pain in adults

The purpose of the present pilot study was to explore the moderating role of basal inflammation on the effects of behavioral pain treatment in 41 patients with long-standing pain. Baseline pro-inflammatory status moderated behavioral treatment outcomes: higher pre-treatment levels of Tumor Necrosis Factor (TNF)-α and Interleukin (IL)-6 were related to less improvement in pain intensity, psychological inflexibility and in mental health-related quality of life. The treatment outcomes improved in the subgroup that had low levels of pro-inflammatory cytokines at baseline, while the subjects with higher pro-inflammatory status did not. Altogether, results indicate that low-grade inflammation may influence the behavioral treatment outcomes and provide a possible explanation of the heterogeneity in treatment response.

Relationship of Objectively-Measured Habitual Physical Activity to Chronic Inflammation and Fatigue in Middle-Aged and Older Adults

BACKGROUND

Habitual (non-exercise) physical activity (PA) declines with age, and aging-related increases in inflammation and fatigue may be important contributors to variability in PA.

METHODS

This study examined the association of objectively-measured PA (accelerometry over 7 days) with inflammation (plasma interleukin-6 and C-reactive protein) and with self-reported fatigue (SF-36 Vitality) at baseline and 18 months after a diet-induced weight loss, exercise, or diet-induced weight loss plus exercise intervention in 167 overweight/obese, middle-aged, and older adults.

RESULTS

At baseline, individuals with higher plasma interleukin-6, as well as those who reported feeling less energetic (more fatigued), took less steps per day and had lower PA energy expenditure and minutes of light and moderate-vigorous PA (p < .05 for all). At the 18-month follow-up, inflammation was lower in both weight loss groups, fatigue was reduced in all three groups with larger decreases in the combined group, and mean levels of habitual PA were not changed in any group. In longitudinal analyses with all groups combined, we found that participants reporting larger increases in vitality (eg, declines in fatigue) had greater increases in PA (p < .05 for all). Also, changes in steps/d and physical activity energy expenditure were indirectly associated with changes in interleukin-6 (β [SEM] for steps/d = -565 [253]; β [SEM] for physical activity energy expenditure = -22.4 [10.17]; p < .05).

CONCLUSIONS

Levels of habitual PA are lower in middle-aged and older adults with higher levels of chronic inflammation and greater self-reported fatigue. In addition, participants who experienced greater declines in inflammation during the interventions had greater declines in fatigue and larger increases in PA.

Interleukin-6 and tumor necrosis factor-α are associated with quality of life-related symptoms in pulmonary arterial hypertension

RATIONALE

Inflammation is associated with symptoms in many chronic illnesses; however, this link has not been established in pulmonary arterial hypertension.

OBJECTIVES

The objective of this study was to investigate the association between inflammatory markers and quality of life-related symptoms in patients with pulmonary arterial hypertension. We hypothesized that higher circulating IL-6 and tumor necrosis factor-α levels would be associated with worse quality of life-related symptoms.

METHODS

We performed a secondary analysis using baseline and 3-month assessments of 62 subjects in a clinical trial of aspirin and simvastatin to determine the association between plasma IL-6 and tumor necrosis factor-α levels and the Medical Outcomes Study Short Form-36 subscales (pain, vitality, mental health).

MEASUREMENTS AND MAIN RESULTS

The mean age was 49.7±13.4 years; 87% were female. Higher IL-6 levels were significantly associated with lower Medical Outcomes Study Short Form-36 subscale scores, indicating worse bodily pain, vitality, and mental health (all P<0.01). Higher tumor necrosis factor-α levels were significantly associated with increased bodily pain, but better mental health scores.

CONCLUSIONS

IL-6 and tumor necrosis factor-α levels are associated with certain quality of life domains in patients with pulmonary arterial hypertension. Clinical trial registered with www.clinicaltrials.gov (NCT00384865).

Aerobic exercises alleviate symptoms of fatigue related to inflammatory cytokines in obese patients with type 2 diabetes

BACKGROUND

Non-insulin dependent diabetic patients frequently suffer from fatigue symptoms that result from chronic systemic inflammation. Aerobic exercise was proved to modulate systemic inflammation.

OBJECTIVE

This study was an attempt to measure the impact of aerobic exercises on fatigue symptoms related to systemic inflammation in obese patients with type 2 diabetes.

METHODS

Eighty obese patients with type 2 diabetes participated in the present study, their age ranged from 40-58 years and their BMI ranged from 31-36 kg/m2 and were assigned to two subgroups; group (A) received aerobic exercise training for 12 weeks and group (B) received no exercise training for 3 months. Measurements of fatigue symptoms and markers of systemic inflammation were assessed before and at the end of the study for all participants in both groups.

RESULTS

The mean values of inflammatory markers (IL-6 and TNF-α) and Multidimensional Fatigue Inventory (MFI) was significantly decreased in group (A), while changes were not significant in group (B). Moreover, there were significant differences between mean levels of the investigated parameters in group (A) and group (B) at the end of the study.

CONCLUSION

Treadmill walking exercise training is an effective treatment policy to improve symptoms of fatigue related to inflammatory cytokines in obese patients with type 2 diabetes.

Delayed-release prednisone improves fatigue and health-related quality of life: findings from the CAPRA-2 double-blind randomised study in rheumatoid arthritis

OBJECTIVES

Like morning stiffness, fatigue is a common, debilitating symptom of rheumatoid arthritis (RA). Delayed-release (DR) prednisone is designed for evening administration (approximately 22:00) and releases 4 h later to coincide with the rise of nocturnal inflammatory cytokines associated with development of morning stiffness. The impact of DR prednisone on fatigue and other related patient-reported outcomes was analysed with data obtained from the Circadian Administration of Prednisone in Rheumatoid Arthritis (CAPRA) 2 study.

METHODS

Patients with symptomatic RA (n=350) despite treatment with a disease-modifying antirheumatic drug (DMARD) were randomised 2:1 to receive additional therapy with DR prednisone 5 mg or placebo once daily for 12 weeks. Fatigue was assessed using validated instruments: the fatigue scale of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) and the vitality domain of the Short Form-36 (SF-36). General quality of life was assessed using the general score and individual domains of Functional Assessment of Cancer Therapy-General (FACT-G) and SF-36.

RESULTS

The change from baseline to week 12 in FACIT-F score was statistically significantly different with DR prednisone/DMARD (3.8) versus placebo/DMARD (1.6; difference 2.2, p=0.0032). Improvement in FACIT-F score correlated positively with clinical response. Compared with placebo/DMARD, DR prednisone/DMARD showed a significantly greater improvement in SF-36 vitality score (5.6, p=0.001), physical component of SF-36 (2.3, p=0.0003) and general score with FACT-G (2.6, p=0.0233).

CONCLUSIONS

DR prednisone in addition to a DMARD significantly improves fatigue and other aspects of health-related quality of life in patients with symptomatic RA compared with DMARD treatment alone.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT00650078.

Fatigue in immune thrombocytopenia

Fatigue is an important aspect of health-related quality of life from the patient perspective and can have significant socio-economic consequences. It is a common feature of chronic illnesses and a significant number of both adults and children with immune thrombocytopenia (ITP) suffer from fatigue. Reliable, validated fatigue scales have been developed for use in ITP. These will facilitate future investigation of its pathogenesis and the effectiveness of intervention. Acute inflammation acts on neural and endocrine systems resulting in 'sickness behaviour', an adaptive response to infection and injury. Inflammation is also thought to cause fatigue in chronic disease and immune dysregulation in ITP appears to have a number of pro-inflammatory components. Clinicians should consider fatigue when assessing the burden of disease. Although effective ITP-directed therapy can improve fatigue, a number of fatigue-directed strategies may also need to be considered.

Measuring fatigue as a symptom in COPD: From descriptors and questionnaires to the importance of the problem

Fatigue is a symptom commonly diagnosed in cancers and in many other chronic debilitating diseases and is one of the main therapeutic targets for various pharmacologic and non-pharmacologic interventions. However, in chronic obstructive pulmonary disease (COPD), this symptom, which can be considered as the main extrapulmonary clinical feature of the disease, can impact significantly on the health-related quality of life of the patients. The aims of this review are to discuss the issues related to fatigue assessment in COPD and to highlight the importance of this symptom in this setting based on the data retrieved from articles published between 1987 through August 2014 available on MEDLINE database. Fatigue can be measured by various scales or questionnaires that are designed for generic purposes or for COPD-related purposes but is still underdiagnosed and undertreated. This is due to the fact that its clinical and prognostic relevance are not appropriately acknowledged. The early identification of fatigue clinical descriptors from patients' reports could help with better management of this symptom.

Fatigue is associated with serum interleukin-6 levels and symptoms of depression in patients on chronic hemodialysis

CONTEXT

Little is known about activated immune-inflammatory pathways and interleukin-6 (IL-6) in the development of fatigue and/or depression in patients with end-stage renal disease on chronic hemodialysis (HD).

OBJECTIVES

To evaluate the possible correlation between fatigue and serum levels of IL-6 in patients on chronic HD.

METHODS

One hundred HD patients were assessed for the presence of fatigue using the SF-36 Vitality subscale and were administered the Beck Depression Inventory (BDI), the Hamilton Anxiety Rating Scale (HARS), the Mini-Mental State Examination (MMSE), the activities of daily living (ADL), and the instrumental activities of daily living (IADL). We also calculated the time of recovery after hemodialysis (TIRD) and the number/severity of comorbidities using the Charlson Comorbidity Index (CCI). Laboratory parameters were measured as well as serum IL-6.

RESULTS

Forty-three patients constituted the fatigued group and 57 the nonfatigued group. Age, CCI, BDI, HARS, and TIRD were significantly higher in fatigued patients than in the nonfatigued patients. Conversely, the scores of ADL, IADL, and MMSE were significantly lower in fatigued than in nonfatigued patients. Serum IL-6 levels (pg/mL) were higher in the fatigued group (5.1 ± 3.4) than in the nonfatigued group (1.6 ± 1.5; P < 0.001); serum albumin and creatinine levels were significantly lower. Twenty-six patients (26%) had no symptoms of depression (BDI score <10), and 74 patients (74%) had symptoms of depression (BDI score >9). Patients with a BDI score >9 were older; had a higher CCI; a lower MMSE; a higher TIRD; lower serum albumin, creatinine, and urea levels; and higher serum IL-6 levels. The correlation analyses showed that the score of the SF-36 Vitality subscale was associated with age, dialytic age, TIRD, ADL, IADL, CCI, BDI, HARS, MMSE, serum urea, creatinine, albumin, and IL-6 levels. On multivariate general linear model analyses, with fatigue as the dependent variable and gender as a second factor, BDI and serum IL-6 levels were independently associated with the score of the SF-36 Vitality subscale. A canonical correlation analysis was performed including in the model fatigue, BDI, and biomarkers; the correlation was 0.679 (R(2) = 0.462). Fatigue, BDI, and IL-6 among biomarkers showed the strongest association with the underlying construct (standardized canonical coefficients = -0.989, 0.015, and 0.852, respectively), thus explaining a correlation of IL-6 with both depression and fatigue.

CONCLUSION

Fatigue was significantly associated with symptoms of depression and serum IL-6 levels in patients receiving chronic HD.

Glucose control and fatigue in type 2 diabetes: the mediating roles of diabetes symptoms and distress

AIM

The purpose of this study was to examine the mediating influence of diabetes health characteristics (diabetes distress, depression symptoms and diabetes symptoms) on the relationship between glucose control and fatigue in adults with type 2 diabetes.

BACKGROUND

In patients with type 2 diabetes, fatigue is common and can affect diabetes self-management behaviours. Although long thought to result from hyperglycaemia, little evidence supports a relationship between fatigue and glucose control.

DESIGN

A cross-sectional, descriptive study design was used.

METHOD

Data were combined from two studies conducted at a large urban university in the Midwestern United States, resulting in a total sample of 155 urban-dwelling adults with type 2 diabetes. Data were collected over the course of 6 days from 2013-March 2014. Fatigue and related biological and psychological phenomena were measured to perform path analyses using structural equation modelling methods. The STATA software was used to analyse the data.

FINDINGS

In patients with A1C less than or equal to 7%, fatigue was related to diabetes distress and diabetes symptoms, but not to A1C directly or indirectly. In the group with A1C greater than 7%, fatigue was indirectly related to A1C; this relationship was mediated through diabetes symptoms, depression and diabetes distress.

CONCLUSION

Our findings suggest that fatigue is indirectly related to glucose control, but only in patients who have elevated A1C levels. In those with adequate glucose control, fatigue is mainly influenced by the presence of diabetes symptoms and distress. In both groups, the number and severity of diabetes symptoms were the strongest predictors of fatigue, regardless of blood glucose control.

Safety of aerobic exercise in people with diabetic peripheral neuropathy: single-group clinical trial

BACKGROUND

Exercise is recommended for people with diabetes, but little is known about exercise in people with diabetic peripheral neuropathy (DPN).

OBJECTIVE

The primary purpose of this preliminary study was to examine adverse events (AEs) during moderate-intensity, supervised aerobic exercise in people with DPN. The secondary purpose was to examine changes in fatigue, aerobic fitness, and other outcomes after intervention.

DESIGN

This was a single-group preliminary study.

SETTING

The setting was an academic medical center.

PARTICIPANTS

Participants were 18 people who were sedentary and had type 2 diabetes and peripheral neuropathy (mean age=58.1 years, SD=5).

INTERVENTION

The intervention was a supervised 16-week aerobic exercise program (3 times per week at 50% to >70% oxygen uptake reserve).

MEASUREMENTS

Adverse events were categorized as related or unrelated to the study, anticipated or unanticipated, and serious or not serious. Outcomes included fatigue (Multidimensional Fatigue Inventory), cardiovascular fitness (peak oxygen uptake), body composition (dual-energy x-ray absorptiometry), sleep quality, plasma metabolic markers, and peripheral vascular function.

RESULTS

During the study, 57 nonserious AEs occurred. Improvements were found in general fatigue (mean change=-3.5; 95% confidence interval [95% CI]=-1.3, -5.3), physical fatigue (mean change=-3.1; 95% CI=-1.2, -5.0), peak oxygen uptake (mean change=1.1 mL·kg(-1)·min(-1); 95% CI=0.2, 1.9), total body fat (mean change=-1%; 95% CI=-0.3, -1.7), fat mass (mean change=-1,780 g; 95% CI=-616.2, -2,938.7), and peripheral blood flow (mean change=2.27%; 95% CI=0.6, 4.0).

LIMITATIONS

This was a small-scale, uncontrolled study. A future randomized controlled trial is needed to fully assess the effects of exercise on the outcomes.

CONCLUSIONS

This study provides new support for supervised aerobic exercise in people with DPN. However, it is important for physical therapists to carefully prescribe initial exercise intensity and provide close monitoring and education to address the anticipated AEs as people who are sedentary and have DPN begin an exercise program.