The associations of adiposity, physical activity and inflammation with fatigue in older adults

Prevalence of Fatigue, Risk Factors, and Relationship With Self-Rated Health Six Months After ICU Discharge in Japan: An Ambidirectional Cohort Study

Background Fatigue presents an important challenge for patients discharged from intensive care units (ICUs). Despite its importance, data on the prevalence and clinical impact of post-ICU fatigue remain limited. In particular, the proportion of patients in clinical settings in Japan who find fatigue distressing, as well as the associations between fatigue, risk factors, and self-rated health, have not been fully explored using validated fatigue measures. Therefore, this study aimed to assess the prevalence of fatigue, identify its associated risk factors, and examine the relationship between fatigue and self-rated health status six months after ICU discharge in Japan. Methods This single-center, ambidirectional cohort study administered a survey to patients aged ≥18 years, six months after ICU discharge, to assess fatigue and self-rated health. Retrospective data were also collected from patients' medical records during hospitalization. Fatigue prevalence was the primary endpoint, measured using the cutoff value of the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) scale. Logistic regression analysis was performed to identify risk factors for fatigue. Locally weighted scatterplot smoothing (LOWESS) plots were generated with FACIT-F scale scores, and the association between fatigue and EuroQol 5 Dimensions 5-Level Visual Analog Scale (EQ-VAS) was analyzed. Results Questionnaires were sent to 87 patients, of whom 81 (93.1%) responded. Eight patients (9.9%) with missing FACIT-F scores were excluded, leaving 73 patients for analysis. The median (interquartile range) age of eligible patients was 74 (63-81) years, and 33 patients (45%) were male. Forty-six patients (63%) reported fatigue. Multivariate analysis identified a higher body mass index (BMI) at ICU admission as an independent risk factor for fatigue (odds ratio (OR) = 1.195; 95% confidence interval (CI) 1.018-1.447; p < 0.05). EQ-VAS scores were significantly lower in the fatigue group (OR 72.5, 95% CI 60-83.8 vs. OR 90, 95% CI 80-90; p < 0.01). Conclusion This study found that many patients in Japanese ICUs experience fatigue, even when disease severity is low. Additionally, BMI at ICU admission was identified as an independent risk factor for fatigue six months after ICU discharge. Regular follow-up on fatigue after ICU discharge is essential for improving long-term outcomes.

Inflammation is associated with pain and fatigue in older adults

Introduction

Increasing evidence suggests that inflammation may play a pivotal role in the development of chronic pain and fatigue in aging individuals. This study investigated the relationship between three inflammatory markers (IL-6, CRP, and TNFα) and pain and fatigue, both cross-sectionally and longitudinally, in a sample of older adults from the Saint Louis Personality and Aging (SPAN) study.

Methods

SPAN study participants provided blood samples at two in-person sessions approximately 2 years apart for the analysis of the inflammatory biomarkers IL-6, CRP, and TNFα. Pain and fatigue were assessed using the RAND-36 Health Status Inventory. Correlations (with false discovery rate correction for multiple testing) and follow-up linear regressions including potentially confounding demographic (e.g., annual household income) and health (e.g., BMI, medication use) covariates were used to estimate cross sectional and longitudinal associations. Analytic ns ranged from 533 to 815.

Results

Cross-sectional analyses revealed that higher IL-6 and CRP were associated with greater reported pain and fatigue, even after accounting for covariates (βs > .098, ps < .05). TNFα was associated with greater fatigue only (β = .100, p = .012). Longitudinally, CRP and IL-6 predicted future pain and fatigue, although only the relationship between CRP and future fatigue survived the inclusion of covariates (β = .104, p = .022). Both pain and fatigue predicted higher levels of IL-6 and CRP approximately 2 years later, although only the associations with IL-6 survived the inclusion of covariates (βs > .12, ps < .01).

Discussion

Our study adds to a growing body of literature showing that inflammation is associated with greater pain and fatigue in older adults. Our longitudinal data showing temporal bidirectional associations is consistent with evidence from non-human animal models that heightened inflammation causally contributes to fatigue and also suggests that the experience of pain and fatigue may contribute to inflammation. It will be important for future work to identify how lifestyle factors associated with pain and fatigue (e.g., physical activity) may contribute to these associations.

Measuring Self-Efficacy for Exercise among Older Adults: Psychometric Properties and Measurement Invariance of a Brief Version of the Self-Efficacy for Exercise (SEE) Scale

(1) Background: Physical activity is known to promote health and psychological well-being in older adults, yet global inactivity rates in this population remain high. Among the factors associated with physical activity, self-efficacy for exercise represents a key predictor for developing effective interventions in older adults. This study aimed to validate the Self-Efficacy for Exercise Scale (SEE) in individuals over 65. (2) Methods: A sample of 726 older adults from the USA and Italy (51.1% females; age range = 65-95 years; Mage = 72.57, SDage = 6.49) completed the SEE, along with the Godin-Shepard Leisure-Time Physical Activity Questionnaire (GSLTPAQ), the Big Five Inventory 2-Extra Short Form (BFI-2-XS), and the 12-item Short Form Health Survey (SF-12). (3) Results: The SEE showed a Cronbach's Alpha of 0.88 and a Composite Reliability of 0.89. Moreover, it demonstrated a unidimensional factor structure and good fit indices. Full measurement invariance was achieved across gender and age, while partial scalar invariance was found across countries, suggesting minor cultural differences. Correlation with the GSLTPAQ, the BFI-2-XS, and the SF-12 support the convergent and nomological validity of the SEE. (4) Conclusions: These findings provide evidence that the SEE is a reliable and valid measure of self-efficacy for exercise among older adults and that the items are interpreted similarly across different ages, genders, and cultures.

Associations of three differential white blood cell counts, platelet counts, and their derived inflammatory indices with cancer-related fatigue in patients with breast cancer undergoing chemotherapy

PURPOSE

Inflammation is thought to be a vital element in the etiology of cancer-related fatigue (CRF), and circulating blood cell parameters could be important markers of inflammatory response. However, the associations of several major blood cell counts and their derived inflammatory indices with CRF are not well described. The present study aimed to establish whether a relationship exists between the counts of three white blood cell (WBC) types, platelets, and CRF and investigate whether several systemic inflammatory indices were associated with CRF in patients with breast cancer (BC).

METHODS

A cross-sectional survey was conducted with a sample of 824 patients with BC undergoing chemotherapy. The cancer fatigue scale was administered to assess CRF. Hematological indicators, including neutrophils, lymphocytes, monocytes, and platelets, were retrieved from routine blood test. Network analyses were used to examine the associations among them.

RESULTS

Among 824 participants, the mean score of CRF was (27 ± 10), ranging from 0 to 57. The results of network models indicated that physical fatigue was negatively linked to lymphocyte counts (weight =  - 0.161), and affective fatigue was positively associated with neutrophil counts (weight = 0.070). Additionally, physical fatigue was positively linked to the platelet-to-lymphocyte ratio (PLR) (weight = 0.049).

CONCLUSION

There were preliminary associations of counts of three WBC types, platelet counts, and systemic inflammatory indices, with distinct dimensions of CRF in patients with BC. Findings provide empirical support for the cellular basis of fatigue-associated inflammatory states.

Association between Muscle Fatigability, Self-Perceived Fatigue and C-Reactive Protein at Admission in Hospitalized Geriatric Patients

Background: The capacity to perceived vitality (CPV) ratio is a novel measure for intrinsic capacity or resilience based on grip work and self-perceived fatigue. CPV has been associated with pre-frailty in older adults and post-surgery inflammation in adults. To better understand the utility of this measure in a frail population, we examined the association between CPV and inflammation in geriatric inpatients. Methods: Data were obtained from 104 hospitalized geriatric patients. The average age of participants was 83.3 ± 7.5 years, and 55.8% of participants were women. In the cross-sectional analyses, associations between C-reactive protein (CRP), grip work (GW), self-perceived fatigue (SPF) and the CPV ratio (higher values indicate better capacity) were examined using linear regression adjusted for confounders. Results: The adjusted association between CRP (abnormal vs. normal) and the CPV ratio was not statistically significant (B = -0.33, 95% CI = -4.00 to 3.34). Associations between CRP and GW (B = 25.53, 95% CI = -478.23 to 529.30) and SPF (B = 0.57, 95% CI = -0.64 to 1.77) were also not statistically significant. Similar results were found in unadjusted models and analyses of cases with complete data. Conclusions: In this frail group of geriatric inpatients, inflammation, routinely assessed with CRP, was not associated with CPV or its components, GW and SPF. Further research is needed to explore whether CPV is a useful indicator of frailty or recovery capacity in hospitalized geriatric patients.

C-Reactive Protein and Specific Depression Symptoms Among Older Adults: An Exploratory Investigation of Multi-Plane Networks Using Cross-Sectional Data From NHANES (2017-2020)

INTRODUCTION

Studies investigating the association between C-reactive protein (CRP) and depression among older adults have yielded inconsistent results. We suspect that this may be due to varying associations between CRP and particular depression symptom criteria, and we addressed this challenge using network analysis.

METHODS

We used cross-sectional data from prepandemic National Health and Nutrition Examination Survey questionnaires (2017-2020) and included a sample of 1698 adults aged 65 years or older. Depression symptoms were assessed using the Patient Health Questionnaire-9. Unregularized Mixed Graphical Models were estimated using the R package mgm before and after adjusting for relevant sociodemographic, clinical, and lifestyle covariates.

RESULTS

In the model with no covariates, the only symptom criterion associated with CRP was "appetite problems." This association remained robust after controlling for all covariates. Although not associated with CRP, other criteria such as "fatigue" and "concentration difficulty" showed associations with important covariates for older adults such as white blood cell count or hemoglobin, respectively.

DISCUSSION

The CRP-related variability in the depression symptom network that we have demonstrated may help explain the reported inconsistencies. The present study stands as exploratory, and future research should focus on applying longitudinal designs and including several other inflammatory proteins and covariates that were not measured in the current network model.

Cross-sectional and prospective association between internet addiction and risk of fatigue among Chinese college students

Severe internet addiction (IA) is associated with a higher risk of musculoskeletal pain, but whether there is a significant prospective association between IA and fatigue is unclear. This study aimed to examine the association between IA and fatigue level among Chinese college students. A cross-sectional (n = 1011) and prospective study (n = 653) was conducted to examine the association between IA and risk of fatigue. IA was measured using Young internet addiction test. Fatigue level was evaluated using the Chalder fatigue scale. Multivariate logistic regression analyses showed a cross-sectional association between IA and the risk of fatigue. The odds ratios (95% CIs) of fatigue for normal, mild, and moderate to severe groups were 1.00 (reference), 1.88 (1.20, 2.95), and 5.60 (3.33, 9.42), respectively (P for trend: <0.001). Similarly, multivariate logistic regression analyses also revealed a significant prospective relationship between IA and the risk of fatigue during the 1-year follow-up period. The odds ratios (95% CIs) of fatigue for normal, mild, and moderate to severe groups were 1.00 (reference), 1.56 (0.67, 3.67), and 3.29 (1.08, 10.04), respectively (P for trend: 0.046). Our findings indicate that IA is positively related to risk of fatigue among Chinese college students. Further interventional studies are needed to explore the causality underlying the effects of IA on fatigue.

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.

Intuitive Eating and Biomarkers Related to Cardiovascular Disease in Older Adults

OBJECTIVE

Examine whether exercise and diet motivation are associated with 4 biomarkers related to cardiovascular disease.

DESIGN

Cross-sectional analysis. Data collection involved questionnaires, blood draws, body composition assessments, and accelerometry.

SETTING

Small, midwestern college town.

PARTICIPANTS

Community older adults (≥ 58 years of age; n = 79) recruited through convenience sampling; the sample was representative of the population of interest for some demographic characteristics (eg, age and sex) but not representative of other characteristics (eg, level of activity).

VARIABLES MEASURED

Independent variables comprised self-reported intrinsic exercise motivation (Behavioral Regulation for Exercise Questionnaire-3) and intuitive eating (Intuitive Eating Scale-2). Dependent variables included inflammatory proteins (C-reactive protein and interleukin-6) and lipid levels (low-density lipoprotein/high-density lipoprotein and triglycerides) quantified from blood samples. Covariates included age, body mass index, sex, and objective physical activity measured by accelerometers worn for 7 days.

ANALYSIS

Multiple linear regression was used to assess the association between diet and exercise motivation and biomarker outcomes; we analyzed 4 regression models (1 for each biomarker). Significance level P < 0.05.

RESULTS

Greater intuitive eating was associated with a lower low-density lipoprotein/high-density lipoprotein ratio (β = -0.45, P = 0.001) and lower triglycerides (β = -0.37, P = 0.003). Intrinsic exercise motivation was not associated with the biomarkers.

CONCLUSIONS AND IMPLICATIONS

Intuitive eating may be a key determinant of certain biomarkers and could be a viable target for interventions to help decrease the risk of cardiovascular disease among older adults.

Evaluating Test-Retest Reliability of Fatigability in Chronic Stroke

OBJECTIVES

The subjective nature of fatigue may contribute to inconsistencies in prevalence rates for post-stroke fatigue. More objective performance fatigue measures may offer a more reliable construct of fatigue. Our goal was to establish test-retest reliability of fatigability in stroke during 6-minute walk (6MW) testing. Relationships between post-stoke fatigability and other constructs were assessed.

MATERIALS AND METHODS

Twenty-three hemiparetic stroke survivors underwent two 6MW tests with portable metabolic monitoring performed at least 48 hours apart. Fatigability was defined as ratio of change in walking speed to distance covered during the 6MW. 6MW oxygen consumption (VO2), peak aerobic capacity (VO2peak), walking speed over-ground, dynamic gait index, fatigue, falls efficacy, and BMI were measured.

RESULTS

Fatigability was highly correlated between both 6MW trials (ICC = 0.99, p < 0.001) with no significant difference between trials (0.08, p = 0.48). The strongest correlation was between fatigability and 6MW VO2 trial 1 and 2 (r = 0.92, p < 0.001 and r = 0.95, p < 0.001, respectively). Moderate-to-strong relationships were observed between fatigability for 6MW and fastest-comfortable walking speed (r = -0.82 and -0.77), self-selected walking speed (r = -7.8 and -0.78), 6MW walking speed (r = -0.80 and 0.80, VO2peak (r = -0.47 and -0.48) (p < 0.001), and DGI (r = -0.70 and -0.68, p < 0.001).

CONCLUSION

This study establishes test-retest reliability for an objective measure of fatigue in stroke-related disability. The strong correlations between fatigability and other functional measures also provides insight into the contributors underlying fatigability in this population.

REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01322607.

Fatigue and the prediction of negative health outcomes: A systematic review with meta-analysis

INTRODUCTION

Fatigue is a common complaint among older adults. Evidence grows that fatigue is linked to several negative health outcomes. A general overview of fatigue and its relationship with negative health outcomes still lacks in the existing literature. This brings complications for healthcare professionals and researchers to identify fatigue-related health risks. Therefore, this study gives an overview of the prospective predictive value of the main negative health outcomes for fatigue in community-dwelling older adults.

METHODS

PubMed, Web of Knowledge and PsycINFO were systematically screened for prospective studies regarding the relationship between fatigue and negative health outcomes resulting in 4595 articles (last search 5th March 2020). Meta-analyses were conducted in RevMan using Odds ratios (ORs), Hazard ratios (HRs) and relative risk ratios (RR) that were extracted from the included studies. Subgroup-analyses were performed based on (1) gender (male/female), (2) length of follow-up and (3) fatigue level (low, medium and high).

RESULTS

In total, thirty articles were included for this systematic review and meta-analysis encompassing 152 711 participants (age range 40-98 years), providing information on the relationship between fatigue and health outcomes. The results showed that fatigue is related to an increased risk for the occurrence of all studied health outcomes (range OR 1.299-3.094; HR/RR 1.038-1.471); for example, mortality OR 2.14 [1.74-2.63]; HR/RR 1.44 [1.28-1.62]), the development of disabilities in basic activities of daily living (OR 3.22 [2.05-5.38]), or the occurrence of physical decline (OR 1.42 [1.29-1.57]).

CONCLUSION

Overall fatigue increases the risk for developing negative health outcomes. The analyses presented in this study show that fatigue related physical decline occurs earlier than hospitalization, diseases and mortality, suggesting the importance of early interventions.

Body Mass Index, Physical Activity Habits and Physical Function Contribute to Fatigue in the Rest Home Residents

BACKGROUNDS

Fatigue is a common complaint in older adults living in rest homes. The aim of this study was to investigate the factors associated with fatigue among older adults living in a rest home.

METHODS

This cross-sectional study was carried out with a total of 92 older adults. Fatigue was evaluated by the Fatigue Severity Scale (FSS). The sociodemographic characteristics, quadriceps and handgrip strength, functional capacity and physical function were assessed using a structured questionnaire, digital dynamometers, 6-minute walking test and Short Physical Performance Battery, respectively.

RESULTS

The prevalence of fatigue was 67.4%. FSS showed significant correlations with age, female gender, body mass index, physical activity habits, quadriceps strength, handgrip strength, functional exercise capacity, and physical function. However, in the regression analysis, only body mass index, physical activity habits and physical function were responsible for 51% of the variance in fatigue among rest home residents. Physical activity habits and physical function were the best predictors of fatigue explaining 47.5% of variance.

CONCLUSION

This study demonstrated that body mass index, physical activity habits and physical function contributed to fatigue in rest home residents. These factors can be used to identify individuals at high risk of fatigue and to attenuate fatigue levels.

Longitudinal Relationship Between Interleukin-6 and Perceived Fatigability Among Well-Functioning Adults in Mid-to-Late Life

BACKGROUND

Chronically elevated interleukin-6 (IL-6) levels contribute to fatigue and functional decline via multiple pathways that often lead to frailty. Lesser known is the contribution of IL-6 to fatigue in relation to a standardized workload (fatigability), a precursor to functional decline. Therefore, the purpose of this study was to examine the longitudinal relationship between IL-6 and fatigability.

METHODS

About 985 participants from the Baltimore Longitudinal Study of Aging (mean age: 70 ± 10 years) were evaluated every 1-4 years. IL-6 was measured in fasting serum samples at each visit and log-transformed for analyses. Perceived fatigability (PF) was defined as self-reported exertion (rate of perceived exertion; RPE) after a 5-min, 0.67 m/s, 0% grade treadmill walk. Continuous and categorical associations between IL-6 (baseline and repeated measures) and PF were assessed using generalized estimating equations, adjusting for demographics, behavioral factors, and comorbid conditions.

RESULTS

In fully adjusted continuous models, twofold higher baseline IL-6 was associated with a 0.28 higher RPE (p = .03). This relationship tended to remain constant annually (baseline log IL-6 by time interaction p = .29). To provide clinical relevance, the sample median (3.7 pg/mL) was used to examine high versus low IL-6 levels. Over time, the high group reported an average 0.25 higher RPE (p = .03) than the low group. Annual change in logged IL-6 was not associated with annual change in PF (p = .48).

CONCLUSION

Findings suggest that elevated IL-6 is a biomarker of physiological dysregulation associated with greater fatigability, but there is no longitudinal association between IL-6 and fatigability. Future studies should evaluate whether interventions that aim to reduce inflammation also attenuate fatigability.

Nutritional Status as a Mediator of Fatigue and Its Underlying Mechanisms in Older People

Fatigue is an often-neglected symptom but frequently complained of by older people, leading to the inability to continue functioning at a normal level of activity. Fatigue is frequently associated with disease conditions and impacts health status and quality of life. Yet, fatigue cannot generally be completely explained as a consequence of a single disease or pathogenetic mechanism. Indeed, fatigue mirrors the exhaustion of the physiological reserves of an older individual. Despite its clinical relevance, fatigue is typically underestimated by healthcare professionals, mainly because reduced stamina is considered to be an unavoidable corollary of aging. The incomplete knowledge of pathophysiological mechanisms of fatigue and the lack of a gold standard tool for its assessment contribute to the poor appreciation of fatigue in clinical practice. Inadequate nutrition is invoked as one of the mechanisms underlying fatigue. Modifications in food intake and body composition changes seem to influence the perception of fatigue, probably through the mechanisms of inflammation and/or mitochondrial dysfunction. Here, we present an overview on the mechanisms that may mediate fatigue levels in old age, with a special focus on nutrition.

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.

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.

Body composition, fatigue and exercise in patients with prostate cancer undergoing androgen-deprivation therapy

OBJECTIVES

To investigate the association between lean mass (LM) and fat mass (FM) with fatigue and vitality before and after exercise in patients with prostate cancer already undergoing androgen-deprivation therapy (ADT).

SUBJECTS AND METHODS

Cross-sectional associations between LM and FM with fatigue and/or vitality measures were examined in 229 patients (aged 43-90 years). Prospective analysis was undertaken in 129 patients who underwent a supervised 3-6 months exercise programme (predominantly resistance + aerobic). Whole body and appendicular LM, and total and trunk FM were assessed by dual X-ray absorptiometry. Fatigue was assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-30) and vitality using the Short Form-36.

RESULTS

Based on the EORTC QLQ-30, 19% of patients had clinically relevant fatigue. There was no association between LM and fatigue; however, total (P = 0.013), trunk (P = 0.015) and percentage (P = 0.008) FM were higher in fatigued than not fatigued patients, with total and trunk FM 5.0 and 2.6 kg higher, respectively. For quartiles of vitality, a similar pattern emerged for FM with those in the lowest quartile of vitality having the highest FM values (P = 0.014-0.034). In contrast, following supervised exercise, change in fatigue and vitality were associated with change in total LM (r = -0.182, P = 0.042 and r = 0.309, P = 0.001, respectively) but not FM. Patients fatigued at baseline but not fatigued following the exercise programme gained a median (interquartile range) of 2.1 (0.7-3.2) kg LM.

CONCLUSION

In patients with prostate cancer treated with ADT, body composition is associated with fatigue, with higher total and trunk FM in those with clinically relevant fatigue. However, following exercise those no longer fatigued had an accompanying substantial increase in LM. Modifying body composition, both LM and FM, in patients with prostate cancer may favourably alter cancer-related fatigue levels and should be a target of exercise medicine in this population.

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.

Are BMI and inflammatory markers independently associated with physical fatigability in old age?

Background

Obesity and chronic low-grade inflammation have both been implicated in the onset of physical fatigue. However, few studies have investigated the independence of these associations in older community-dwelling populations. We therefore aimed to investigate the associations of body mass index (BMI) and inflammatory markers at age 60–64 with perceived physical fatigability at age 68 and to assess whether any such associations were independent of each other and potential confounding factors. A secondary aim was to investigate whether any association with BMI extended back into earlier adulthood.

Methods

Participants of the MRC National Survey of Health and Development (N = 1580) had BMI and levels of interleukin-6 (IL-6) and C-reactive protein (CRP) measured during clinical assessments at age 60–64. These were related to self-perceived physical fatigability assessed at age 68 using the Pittsburgh Fatigability Scale (PFS) (total score:0 (no physical fatigue)–50 (extreme physical fatigue)).

Resuts

Women had higher mean PFS scores than men (mean (SD): 16.0 (9.1) vs 13.2 (8.9), p < 0.01). In sex-adjusted models, BMI, CRP and IL-6 were each associated with PFS scores. When all three factors were included in the same model, BMI and IL-6 remained associated with PFS scores whereas CRP did not. After adjustment for a range of potential confounders, associations of BMI and IL-6 with PFS scores were still evident; fully adjusted differences in mean PFS score = 3.41 (95% CI: 0.59, 6.24) and 1.65 (0.46, 2.84) for underweight and obese participants when compared with normal weight and, 2.78 (1.65, 3.91) when comparing those with an IL-6 of 2.51–8.49 pg/mL with levels <1.50.

Conclusions

BMI and inflammation may both be suitable targets for intervention to reduce the burden of physical fatigability in later life. Further, interventions that target both obesity and elevated levels of IL-6 are likely to be more effective than those focusing on only one.

Disparate Habitual Physical Activity and Dietary Intake Profiles of Elderly Men with Low and Elevated Systemic Inflammation

The development of chronic, low-grade systemic inflammation in the elderly (inflammaging) has been associated with increased incidence of chronic diseases, geriatric syndromes, and functional impairments. The aim of this study was to examine differences in habitual physical activity (PA), dietary intake patterns, and musculoskeletal performance among community-dwelling elderly men with low and elevated systemic inflammation. Nonsarcopenic older men free of chronic diseases were grouped as ‘low’ (LSI: n = 17; 68.2 ± 2.6 years; hs-CRP: <1 mg/L) or ‘elevated’ (ESI: n = 17; 68.7 ± 3.0 years; hs-CRP: >1 mg/L) systemic inflammation according to their serum levels of high-sensitivity CRP (hs-CRP). All participants were assessed for body composition via Dual Emission X-ray Absorptiometry (DEXA), physical performance using the Short Physical Performance Battery (SPPB) and handgrip strength, daily PA using accelerometry, and daily macro- and micronutrient intake. ESI was characterized by a 2-fold greater hs-CRP value than LSI (p < 0.01). The two groups were comparable in terms of body composition, but LSI displayed higher physical performance (p < 0.05), daily PA (step count/day and time at moderate-to-vigorous PA (MVPA) were greater by 30% and 42%, respectively, p < 0.05), and daily intake of the antioxidant vitamins A (6590.7 vs. 4701.8 IU/day, p < 0.05), C (120.0 vs. 77.3 mg/day, p < 0.05), and E (10.0 vs. 7.5 mg/day, p < 0.05) compared to ESI. Moreover, daily intake of vitamin A was inversely correlated with levels of hs-CRP (r = −0.39, p = 0.035). These results provide evidence that elderly men characterized by low levels of systemic inflammation are more physically active, spend more time in MVPA, and receive higher amounts of antioxidant vitamins compared to those with increased systemic inflammation.

Depression and peripheral inflammatory profile of patients with obesity

This narrative review will present and discuss clinical data from 16 cross-sectional and 6 longitudinal studies examining the relationship between body mass index (BMI), symptoms of depression and peripheral inflammation. Our aim is to determine which of obesity and depression contributes best to the peripheral low-grade inflammation frequently associated to both conditions. Studies including a complete evaluation of inflammatory markers are scarce and high levels of interleukin-6 (IL-6) and C-reactive protein (CRP) are the most consistent findings associated with obesity and symptoms of depression. Among the cross-sectional studies, seven studies, including a total of 9421 individuals, pointed to BMI as the major factor associated with systemic low-grade inflammation. However, in four studies, including 16,837 individuals, CRP levels remained associated with the symptoms of depression even after correction for BMI, suggestion that in the absence of overweight or obesity other sources of peripheral inflammation might contribute to presence of depressive symptoms. Additionally, another five studies, including 5569 individuals failed to find an association between depression and peripheral inflammation, reinforcing the heterogeneity of this condition. In the longitudinal data, changes in BMI were associated with a reduction in depressive scores at follow-up, after bariatric surgery or after diet. In four longitudinal studies, high levels of CRP were found to be associated with depression even after adjustment for BMI and weight loss, further corroborating the idea that other sources of peripheral inflammation might contribute to depressive symptoms. Thus it seems that both obesity and depressive symptoms can contribute to peripheral inflammation, and once installed the presence of inflammation can contribute to several behavioral alterations that reinforce the cyclic pattern of co-occurrence observed in patients with obesity and MDD. Future clinical studies should focus on strategic efforts to collect new data and to improve or standardize methods for the evaluation of depression, body composition and a more complete inflammatory profile. These approaches are essential for the development of pharmacological and/or non-pharmacological strategies designed to break this cyclic pattern of co-occurrence.

Physical activity but not sedentary activity is reduced in primary Sjögren's syndrome

The aim of the study was to evaluate the levels of physical activity in individuals with primary Sjögren's syndrome (PSS) and its relationship to the clinical features of PSS. To this cross-sectional study, self-reported levels of physical activity from 273 PSS patients were measured using the International Physical Activity Questionnaire-short form (IPAQ-SF) and were compared with healthy controls matched for age, sex and body mass index. Fatigue and other clinical aspects of PSS including disease status, dryness, daytime sleepiness, dysautonomia, anxiety and depression were assessed using validated tools. Individuals with PSS had significantly reduced levels of physical activity [median (interquartile range, IQR) 1572 (594-3158) versus 3708 (1732-8255) metabolic equivalent of task (MET) × min/week, p < 0.001], but similar levels of sedentary activity [median (IQR) min 300 (135-375) versus 343 (223-433) (MET) × min/week, p = 0.532] compared to healthy individuals. Differences in physical activity between PSS and controls increased at moderate [median (IQR) 0 (0-480) versus 1560 (570-3900) MET × min/week, p < 0.001] and vigorous intensities [median (IQR) 0 (0-480) versus 480 (0-1920) MET × min/week, p < 0.001]. Correlation analysis revealed a significant association between physical activity and fatigue, orthostatic intolerance, depressive symptoms and quality of life. Sedentary activity did not correlate with fatigue. Stepwise linear regression analysis identified symptoms of depression and daytime sleepiness as independent predictors of levels of physical activity. Physical activity is reduced in people with PSS and is associated with symptoms of depression and daytime sleepiness. Sedentary activity is not increased in PSS. Clinical care teams should explore the clinical utility of targeting low levels of physical activity in PSS.

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.

Genetic and environmental factors in vascular dementia: an update of blood brain barrier dysfunction

Vascular dementia (VaD) describes a combination of both cognitive and behavioural manifestations associated with variable brain lesions of vascular origin. While vascular risk factors have been implicated in VaD, the relationship is most evident when the factors are considered together and not individually. This review will examine the significance of the integrity of blood brain barrier (BBB) tight junction (TJ) proteins - occludin and claudins in the pathophysiology of VaD. Specifically, some of the genetic contributors to VaD, namely those responsible for the integrity of the BBB, will be reviewed in detail. Moreover, environmental factors will be considered in conjunction with these genes to examine how the interaction of environmental and genetic factors contributes to one's susceptibility to VaD.

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.

Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation

BACKGROUND

Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans.

METHODS

A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model.

RESULTS

A total of 72 studies (n > 50,000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα). Sleep disturbance was associated with higher levels of CRP (ES .12; 95% CI = .05-.19) and IL-6 (ES .20; 95% CI = .08-.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES .09; 95% CI = .01-.17) but not IL-6 (ES .03; 95% CI: -.09 to .14). The extreme of long sleep duration was associated with higher levels of CRP (ES .17; 95% CI = .01-.34) and IL-6 (ES .11; 95% CI = .02-20). Neither sleep disturbances nor sleep duration was associated with TNFα. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNFα. Some heterogeneity among studies was found, but there was no evidence of publication bias.

CONCLUSIONS

Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation.

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.

Influence of traffic-related noise and air pollution on self-reported fatigue

A growing body of evidence suggests that exposure to environmental pollutions is related to health problems. It is, however, questionable whether this condition affects working performance in occupational settings. The aim of this study is to determine the predictive value of age as well as traffic related air and noise pollutions for fatigue. 246 traffic officers participated in this study. Air pollution data were obtained from the local Air Quality Control Company. A sound level meter was used for measuring ambient noise. Fatigue was evaluated by the MFI-20 questionnaire. The general and physical scales showed the highest, while the reduced activity scale showed the lowest level of fatigue. Age had an independent direct effect on reduced activity and physical fatigue. The average of daytime equivalent noise level was between 71.63 and 88.51 dB(A). In the case of high noise exposure, older officers feel more fatigue than younger ones. Exposure to PM10 and O3 resulted in general and physical fatigue. Complex Interactions between SO2, CO and NO2 were found. Exposure to noise and some components of air pollution, especially O3 and PM10, increases fatigue. The authorities should adopt and rigorously implement environmental protection policies in order to protect people.

Inflammation: depression fans the flames and feasts on the heat

Depression and inflammation fuel one another. Inflammation plays a key role in depression's pathogenesis for a subset of depressed individuals; depression also primes larger cytokine responses to stressors and pathogens that do not appear to habituate. Accordingly, treatment decisions may be informed by attention to questions of how (pathways) and for whom (predispositions) these links exist, which are the focus of this article. When combined with predisposing factors (moderators such as childhood adversity and obesity), stressors and pathogens can lead to exaggerated or prolonged inflammatory responses. The resulting sickness behaviors (e.g., pain, disturbed sleep), depressive symptoms, and negative health behaviors (e.g., poor diet, a sedentary lifestyle) may act as mediating pathways that lead to further, unrestrained inflammation and depression. Depression, childhood adversity, stressors, and diet can all influence the gut microbiome and promote intestinal permeability, another pathway to enhanced inflammatory responses. Larger, more frequent, or more prolonged inflammatory responses could have negative mental and physical health consequences. In clinical practice, inflammation provides a guide to potential targets for symptom management by signaling responsiveness to certain therapeutic strategies. For example, a theme across research with cytokine antagonists, omega-3 fatty acids, celecoxib, and exercise is that anti-inflammatory interventions have a substantially greater impact on mood in individuals with heightened inflammation. Thus, when inflammation and depression co-occur, treating them in tandem may enhance recovery and reduce the risk of recurrence. The bidirectional links between depression, inflammation, and disease suggest that effective depression treatments could have a far-reaching impact on mood, inflammation, and health.

Perceived fatigability and metabolic and energetic responses to 6-minute walk test in older women

OBJECTIVE

To determine the relationship between perceived fatigability and oxygen consumption, carbon dioxide production, respiratory exchange ratio and the energy cost of walking in older women.

DESIGN

Observational, cross-sectional study.

PARTICIPANTS

Forty-eight community-dwelling older women were recruited from senior centres in Natal, Rio Grande do Norte, Brazil.

MAIN OUTCOME MEASURES

Participants were evaluated in two different sessions. In the first session, sociodemographic and clinical factors were assessed and accelerometers were delivered. In the second session, the 6-minute walking test (6MWT) was performed and expired gases were analysed. Self-reported levels of fatigue were evaluated on a numerical scale from 1 ('extremely energetic') to 7 ('extremely tired'). Severity scores for perceived and performance fatigability were calculated as the ratio of change in performance and fatigue, respectively, with walking distance. The O2 cost of walking was based on the oxygen consumption rate and the 6MWT walking speed.

RESULTS

No correlation was found between the severity of perceived fatigability and metabolic measures. However, the severity of perceived fatigability was significantly correlated with greater O2 cost (r=0.579, P<0.01), physical activity (r=-0.654, P<0.01), walking distance (r=-0.712, P<0.01) and severity of performance fatigability (r=0.690, P<0.01).

CONCLUSION

Perceived fatigability was not directly associated with metabolic measures; however, greater severity of perceived fatigability was associated with an increase in the O2 cost of walking. Important relationships were also found between greater severity of perceived fatigability and poor functional fitness, high level of energy expenditure and lower level of physical activity.

Poor sleep quality potentiates stress-induced cytokine reactivity in postmenopausal women with high visceral abdominal adiposity

Sleep disturbance is a key behavioral risk factor for chronic medical conditions observed at high rates among overweight and obese individuals. Systemic inflammation, including that induced by stress, may serve as a common biological mechanism linking sleep, adiposity, and disease risk. To investigate these relationships, 48 postmenopausal women (mean age=61.8) completed a standardized laboratory stress task during which time blood was collected at baseline and 30, 50 and 90+ min after stressor onset to assess circulating levels of interleukin (IL)-6, IL-10, and IL-6/IL-10 ratio. Self-reported global sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) while adiposity was estimated by body mass index. Sagittal diameter was obtained in clinic to estimate visceral abdominal adiposity. Multi-level growth curve models revealed that poorer self-reported sleep quality was associated with greater stress-induced increases in IL-6/IL-10 ratio. In terms of adiposity, higher sagittal diameter, but not BMI, was associated with greater IL-6 reactivity (p's<0.05). Further, associations between sleep quality and cytokine reactivity varied as a function of sagittal diameter. Among poor sleepers (1 SD above mean of PSQI score), stress-induced increases in IL-6 and IL-6/IL-10 ratio were significantly steeper in those with high visceral adiposity (1 SD above the mean of sagittal diameter) compared to those with low visceral adiposity (1 SD below the mean of sagittal diameter). In sum, poorer sleep quality and greater visceral adiposity, separately and especially in combination, are associated with greater stress-related increases in systemic inflammation. This research may help elucidate the complex link between sleep, obesity and inflammatory disease risk.

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

Fatigue is frequent in patients with diabetes and this symptom appears to be more prominent in type 2 rather than type 1 diabetic subjects. Chronic inflammation represents one characteristic of type 2 diabetes that may contribute to fatigue symptoms. This possibility was assessed in a sample of 20 type 2 diabetic patients relatively to a group of 20 type 1 diabetic subjects. Specific dimensions of fatigue, including general fatigue, physical fatigue, reduced activity, mental fatigue and reduced motivation, were assessed using the Multidimensional-Fatigue-Inventory (MFI). Biological assays comprised the measurement of serum inflammatory markers [high-sensitive C-reactive-protein (hsCRP), high-sensitive interleukin-6 (hsIL-6), high-sensitive tumor-necrosis-factor-α (hsTNF-α) and neopterin]. Clinical parameters including indexes of adiposity were collected. In comparison to type 1 diabetic subjects, patients with type 2 diabetes exhibited higher fatigue scores, notably in the dimensions of general fatigue, physical fatigue and reduced activity, together with greater levels of inflammatory markers that correlated with indexes of adiposity. Regression analyses controlling for diabetes duration, insulin treatment status, glycemic control and fasting status, indicated that levels of inflammatory markers, in particular hsIL-6, hsCRP and neopterin, were associated with MFI fatigue dimensions in type 2 diabetic patients. Mediation analyses revealed that adiposity did not significantly account for the relationship of inflammatory markers with fatigue scores albeit coefficient regressions decreased somewhat when this variable was controlled for in regression models. These findings indicate that systemic low-grade inflammation relates to fatigue symptoms in patients with type 2 diabetes and suggest the involvement of inflammatory processes in the pathophysiology of diabetes-related fatigue.

Is there a genetic cause of appetite loss?-an explorative study in 1,853 cancer patients

BACKGROUND

Appetite loss has a major impact on cancer patients. It is exceedingly prevalent, is a prognostic indicator and is associated with inferior quality of life. Cachexia is a multi-factorial syndrome defined by a negative protein and energy balance, driven by a variable combination of reduced food intake and abnormal metabolism. Not all cancer patients that experience weight loss have appetite loss, and the pathophysiology between cachexia and appetite loss may thus be different. Knowledge of pathophysiology of appetite loss in cancer patients is still limited. The primary object of this study was to explore the association with 93 predefined candidate single-nucleotide polymorphisms (SNPs) and appetite loss in cancer patients to possibly generate new theories of the pathophysiology of the condition.

METHODS

A total of 1,853 cancer patients were phenotyped according to appetite loss and then genotyped.

RESULTS

After allowing for multiple testing, there was no statistically significant association between any of the SNPs analysed and appetite loss. The ten most significant SNPs in the co-dominant model had observed odds ratios varying from 0.72 to 1.28.

CONCLUSIONS

This large exploratory study could not find any associations with loss of appetite and 93 SNPs with a potential to be involved in appetite loss in cancer patients. This does not however rule out genes putative role in the development of the symptom, but the observed odds ratios are close to one which makes it unlikely that any of the individual SNPs explored in the present study have great importance.

Diet components associated with perceived fatigue in breast cancer survivors

Little is known about the contribution of diet components independent of body composition to persistent fatigue in breast cancer survivors. Therefore, our study aim was to determine the associations among dietary intake and fatigue in relation to and independent of adiposity and physical activity (PA) in breast cancer survivors. Baseline data from 42 breast cancer survivors enrolled in a randomised exercise trial were analysed: fatigue (Functional Assessment of Cancer Therapy for fatigue), diet components (3-day diet record), body mass index, per cent body fat (dual-energy X-ray absorptiometry) and PA (accelerometer). The mean age was 54 ± 9 years with an average body mass index of 30.5 ± 8.1 kg/m(2). Fatigue was positively associated with % of kcal/day fat intake (r = 0.31, P < 0.05) and inversely related to fibre g/day (r = 0.38, P < 0.05) and carbohydrate g/day intake (r = 0.31, P < 0.05). Mean fatigue was greater for participants eating <25 g/day of fibre compared with >25 g/day of fibre (15.7 ± 10.8 versus 6.4 ± 3.7, P < 0.005). No significant associations were noted between fatigue and PA or body composition. Diets high in fibre and low in fat are associated with reduced fatigue in breast cancer survivors. The difference in fatigue for low- versus high-fibre diets exceeded the minimal clinically important difference of three units. Prospective studies evaluating the effect of changing diet on fatigue in breast cancer survivors are warranted.