Ambulatory monitoring of physical activity and symptoms in fibromyalgia and chronic fatigue syndrome

Statistical modeling of acute and chronic pain patient-reported outcomes obtained from ecological momentary assessment

ABSTRACT

Ecological momentary assessment (EMA) allows for the collection of participant-reported outcomes (PROs), including pain, in the normal environment at high resolution and with reduced recall bias. Ecological momentary assessment is an important component in studies of pain, providing detailed information about the frequency, intensity, and degree of interference of individuals' pain. However, there is no universally agreed on standard for summarizing pain measures from repeated PRO assessment using EMA into a single, clinically meaningful measure of pain. Here, we quantify the accuracy of summaries (eg, mean and median) of pain outcomes obtained from EMA and the effect of thresholding these summaries to obtain binary clinical end points of chronic pain status (yes/no). Data applications and simulations indicate that binarizing empirical estimators (eg, sample mean, random intercept linear mixed model) can perform well. However, linear mixed-effect modeling estimators that account for the nonlinear relationship between average and variability of pain scores perform better for quantifying the true average pain and reduce estimation error by up to 50%, with larger improvements for individuals with more variable pain scores. We also show that binarizing pain scores (eg, <3 and ≥3) can lead to a substantial loss of statistical power (40%-50%). Thus, when examining pain outcomes using EMA, the use of linear mixed models using the entire scale (0-10) is superior to splitting the outcomes into 2 groups (<3 and ≥3) providing greater statistical power and sensitivity.

How to Promote Walking in Women with Fibromyalgia: A Look at Catastrophizing, Goal Conflict, and Avoidance from a Self-Emotional Regulatory Perspective

The aim of this study was twofold: to explore the concordance between two measures of physical activity (accelerometer and IPAQ) among female fibromyalgia (FM) patients, as well as to examine the impact of psychosocial variables (catastrophism, activity avoidance) on walking among these patients. Helplessness, activity avoidance, and commitment to physical activity were evaluated in 132 FM women. After the first assessment, an accelerometer was placed by a psychologist on each participant for seven consecutive days. Eight days later, accelerometers were collected, and participants were evaluated again using the IPAQ. Two models were tested to analyze mediation and a moderated mediation effect. The mediating role of activity avoidance between helplessness and minutes walked was corroborated regarding the objective measure of walking. The effect of helplessness on minutes walked during a week was mediated by activity avoidance and assessed by accelerometers. Cognitive variables played a contextual role when trying to promote exercise. Activity avoidance must be understood as a key variable in physical activity promotion, specifically in the promotion of walking with the aim to do exercise in individuals with FM.

The influence of sex on activity in voluntary wheel running, forced treadmill running, and open field testing

Introduction

Physical activity is commonly used for both measuring and treating dysfunction. While preclinical work has been historically biased towards males, the use of both male and female animals is gaining popularity after multiple NIH initiatives. With increasing inclusion of both sexes, it has become imperative to determine sex differences in common behavioral assays. The purpose of this study was to determine baseline sex differences in 3 activity assays: voluntary wheel running, forced treadmill running, and open field testing.

Methods

This was a secondary analysis of sex differences in healthy mice in 3 different assays: Separate mice were used for each assay. Specifically, 16 mice underwent 28 days of voluntary wheel running, 178 mice underwent forced treadmill running, and 88 mice underwent open field testing. Differences between sex across several activity parameters were examined for each assay.

Results

In voluntary wheel running, sex differences with larger effect sizes were observed in distance run, running time, and bout duration, with smaller effect size differences in speed, and no difference in total bouts. In forced treadmill running, differences were shown in time to exhaustion, but no difference in max speed attained. In open field, there were sex differences in active time but not in distance and speed in data aggregated over 30 minutes; however, distance and speed in male mice showed a downward trajectory over the final 20 minutes of testing, whereas females maintained the same trajectory.

Conclusion

These data suggest that male mice demonstrate comparable activity intensity as female mice but do not match female's duration of activity, especially for volitional tasks. Researchers utilizing these assays should account for sex differences as they could potentially mask true findings in an experiment.

Plain English Summary

Physical activity is a common measure to examine function in human subjects with and without disease. Animal models often use measures of physical activity to assess function, yet most of these measures have been done in males only, making interpretation and translation to females and humans difficult. Several measures have been used to measure activity in animals, including those examining voluntary running behavior, maximum capacity, and general activity levels; sex differences between these measures are unclear. We discovered sex differences throughout each of three activity tests. In voluntary running behavior there were large differences between sexes with females running a greater distance and spending more time running. There were small differences in the maximum capacity with females running for a longer period at high intensity. General activity levels showed small differences with females being less active than males. Thus, the greatest differences were found for voluntary running and small differences were found for maximum capacity and general activity levels; differences observed were dependent on the task. Researchers utilizing these assays should account for sex differences as they could potentially mask true findings in an experiment.

The relationship of affective and bodily states with goals and plans to increase physical activity: An 8-day study in students

Planning is an important tool to translate intentions into physical activity (PA) behavior. Affective and bodily states are known to influence how much PA individuals perform, but their impact on to formulation of PA plans is not yet known. The aim of the current study is to explore the effect of within- and between-subject variations in affective and bodily states on the content of PA goals and plans. Over eight consecutive days, 362 students created action and coping plans to achieve their daily PA goals. They also reported their affective and bodily states. Generalized linear mixed effect models were used to analyze the associations between these states and the content of the goals and plans. The results showed that both between- and within-subject variations in affective and bodily states were associated with goals formulated in terms of minutes, the intensity and context of planned activities, and anticipated barriers, though more effects were found for within-subject differences. Affective and bodily states impact daily PA goals and plans, highlighting the dynamic nature of planning. Our findings can be a first step toward personalized suggestions for goals, action plans, and coping strategies that are based on individual affective and bodily states.

Mediating role of physical activity in the relationship between exercise-induced muscle pain and symptom severity in women with fibromyalgia

BACKGROUND

Individuals with fibromyalgia (FM) exhibit generalized hyperalgesia to pain stimuli, and physical activity (PA) is critical to manage FM symptoms.

PURPOSE

This study examined the relationship between exercise-induced muscle pain, symptom severity, and PA in 28 women with FM.

METHODS

Muscle pain rating (MPR) was assessed during 3 minutes of submaximal isometric handgrip exercise, whereas PA and symptom severity were evaluated via self-report questionnaires. The analysis examined the relationship between the variables, with the specific interest in the mediating role of PA in the relationship between exercise-induced muscle pain and symptom severity.

RESULTS

MPR was positively associated with symptom severity (b = 1.89; 95% CI = 0.01, 3.76; P = .048) and inversely associated with PA levels (b = -0.16; 95% CI = -0.30, -0.03; P = .021). PA levels were inversely associated with symptom severity (b = -7.94; 95% CI = -12.46, -3.42; P = .001). After statistically controlling for PA levels, the relationship between MPR and symptom severity was no longer significant (b = 0.60; Wald 95% CI = -1.05, 2.25; P = .474).

CONCLUSION

Results show the link between the variables, and specifically demonstrate that PA mediates the relationship between exercise-induced muscle pain and symptom severity.

Opal Actigraphy (Activity and Sleep) Measures Compared to ActiGraph: A Validation Study

Physical activity and sleep monitoring in daily life provide vital information to track health status and physical fitness. The aim of this study was to establish concurrent validity for the new Opal Actigraphy solution in relation to the widely used ActiGraph GT9X for measuring physical activity from accelerometry epic counts (sedentary to vigorous levels) and sleep periods in daily life. Twenty participants (age 56 + 22 years) wore two wearable devices on each wrist for 7 days and nights, recording 3-D accelerations at 30 Hz. Bland-Altman plots and intraclass correlation coefficients (ICCs) assessed validity (agreement) and test-retest reliability between ActiGraph and Opal Actigraphy sleep durations and activity levels, as well as between the two different versions of the ActiGraph. ICCs showed excellent reliability for physical activity measures and moderate-to-excellent reliability for sleep measures between Opal versus Actigraph GT9X and between GT3X versus GT9X. Bland-Altman plots and mean absolute percentage error (MAPE) also show a comparable performance (within 10%) between Opal and ActiGraph and between the two ActiGraph monitors across activity and sleep measures. In conclusion, physical activity and sleep measures using Opal Actigraphy demonstrate performance comparable to that of ActiGraph, supporting concurrent validation. Opal Actigraphy can be used to quantify activity and monitor sleep patterns in research and clinical studies.

Deficient butyrate-producing capacity in the gut microbiome is associated with bacterial network disturbances and fatigue symptoms in ME/CFS

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained debilitating fatigue, cognitive dysfunction, gastrointestinal disturbances, and orthostatic intolerance. Here, we report a multi-omic analysis of a geographically diverse cohort of 106 cases and 91 healthy controls that revealed differences in gut microbiome diversity, abundances, functional pathways, and interactions. Faecalibacterium prausnitzii and Eubacterium rectale, which are both recognized as abundant, health-promoting butyrate producers in the human gut, were reduced in ME/CFS. Functional metagenomics, qPCR, and metabolomics of fecal short-chain fatty acids confirmed a deficient microbial capacity for butyrate synthesis. Microbiome-based machine learning classifier models were robust to geographic variation and generalizable in a validation cohort. The abundance of Faecalibacterium prausnitzii was inversely associated with fatigue severity. These findings demonstrate the functional nature of gut dysbiosis and the underlying microbial network disturbance in ME/CFS, providing possible targets for disease classification and therapeutic trials.

Sedentary Behavior and Pain after Physical Activity in Women with Fibromyalgia-The Influence of Pain-Avoidance Goals and Catastrophizing

BACKGROUND

Fibromyalgia is characterized by chronic pain and fatigue that triggers a functional disability caused by the lack of activity. Pain catastrophizing may contribute to avoiding activity with the intention of managing pain levels. Based on the sedentary behavior with fibromyalgia, the present study assessed the preference of pain-avoidance goals and pain catastrophizing as mediator and moderator variables, respectively, that influence pain perception after a 6-min-walking test.

METHODS

The sample was composed of 76 women with fibromyalgia (mean age = 55.05, SD = 7.70). Previous sedentary behavior, preference for pain-avoidance goals, and pain catastrophizing were evaluated before starting the walking-test. Subsequently, pain perception was evaluated.

RESULTS

A significant moderated-mediation model was found in which pain-avoidance goals mediated the relationship between sedentarism and pain after a walking-test, and pain catastrophizing moderated the relationship between the preference for pain-avoidance goals and pain perception. Specifically, high levels of pain catastrophizing contributed to increased pain perceptions after completing the test (B = 0.570, p = 0.03, CI 95% (0.09, 0.11)].

CONCLUSIONS

The results suggest that motivational interventions can improve the symptoms because their objectives are focused on managing conflict goals. These interventions should focus on catastrophic cognitions considering that pain catastrophizing is deemed to be one of the major inhibitors of physical activity in fibromyalgia.

Impact of being physically active on the brain electrocortical activity, brain volumetry and performance in the Stroop color and word test in women with fibromyalgia

Physical exercise is one of the treatment approaches with the most robust evidence against fibromyalgia (FM) symptoms. This study aimed to investigate the impact of being physically active on the Stroop Color and Word Test (SCWT) performance as well as to investigate and compare the brain electrocortical activity during SCWT. A total of 31 women completed the SCWT while EEG was recorded. People with FM were divided into two groups (physically and non-physically active) according to the WHO guidelines. Furthermore, magnetic resonance imaging was acquired and health-related quality of life, the impact of the disease, and the six-minute walking test were administered. Physically active group showed better performance in the SCWT, exhibiting less error in name different color patches condition (C), more correct responses in named color-word condition (CW) and higher interference score than non-physically active group. Moreover, a significantly higher theta power spectrum in the Fp1 during the condition C in the SCWT and a higher volume in the right rostral middle frontal gyrus have been found in the physically active group. Furthermore, physically active women with FM showed positively correlations between correct responses in names of colors printed in black condition (W) in the SCWT and theta power in the F3, Fz, Fp2 and F4 scalp positions. Regarding non-physically active women with FM, errors in condition CW negatively correlated with the volume of left superior frontal gyrus, left rostral middle frontal gyrus, right rostral middle frontal gyrus, left caudal middle frontal gyrus and right caudal middle frontal gyrus. Furthermore, physically active group showed increased performance in the 6 min walking test and lower disease impact. Fulfil the physical activity recommendation seems to protect brain health since better SCWT performance, greater frontal theta power and higher volume in the right rostral middle frontal gyrus have been found in physically active women with FM.

FDA/Arthritis Foundation osteoarthritis drug development workshop recap: Assessment of long-term benefit

OBJECTIVE

To summarize proceedings of a workshop convened to discuss the current state of science in the disease of osteoarthritis (OA), identify the knowledge gaps, and examine the developmental and regulatory challenges in bringing these products to market.

DESIGN

Summary of the one-day workshop held virtually on June 22nd, 2021.

RESULTS

Speakers selected by the Planning Committee presented data on the current approach to assessment of OA therapies, biomarkers in OA drug development, and the assessment of disease progression and long-term benefit.

CONCLUSIONS

Demonstrated by numerous failed clinical trials, OA is a challenging disease for which to develop therapeutics. The challenge is magnified by the slow time of onset of disease and the need for clinical trials of long duration and/or large sample size to demonstrate the effect of an intervention. The OA science community, including academia, pharmaceutical companies, regulatory agencies, and patient communities, must continue to develop and test better clinical endpoints that meaningfully reflect disease modification related to long-term patient benefit.

Catastrophizing, Kinesiophobia, and Acceptance as Mediators of the Relationship Between Perceived Pain Severity, Self-Reported and Performance-Based Physical Function in Women with Fibromyalgia and Obesity

Purpose

Individuals with fibromyalgia and obesity experience significant impairment in physical functioning. Pain catastrophizing, kinesiophobia, and pain acceptance have all been identified as important factors associated with the level of disability. The objective of this study was to evaluate the role of pain catastrophizing, kinesiophobia, and pain acceptance as mediators of the association between perceived pain severity and physical functioning in individuals with fibromyalgia and obesity.

Patients and Methods

In this cross-sectional study, 165 women with fibromyalgia and obesity completed self-report questionnaires of perceived pain severity (ie, Numeric Pain Rating Scale), pain catastrophizing (ie, Pain Catastrophizing Scale), kinesiophobia (ie Tampa Scale of Kinesiophobia), pain acceptance (ie, Chronic Pain Acceptance Questionnaire), and perceived physical functioning (ie, Physical Functioning subscale of the Fibromyalgia Impact Questionnaire). In addition, a performance-based test (ie, 6-minute walking test) was conducted to assess objective physical functioning. Two multiple mediation analyses were performed.

Results

Pain acceptance and kinesiophobia mediated the relationship between pain severity and self-reported physical functioning. Pain catastrophizing and kinesiophobia mediated the relationship between pain severity and performance-based functioning.

Conclusion

Pain acceptance, kinesiophobia, and pain catastrophizing should be addressed in rehabilitative intervention to improve physical functioning. Interestingly, the subjective and objective aspects of physical functioning are influenced by different factors. Therefore, interventions for women with fibromyalgia and obesity should focus on factors related to both subjective and performance-based physical functioning.

Actigraphic Physical Activity, Pain Intensity, and Polysomnographic Sleep in Fibromyalgia

INTRODUCTION

Fibromyalgia involves chronic pain and disrupted physical activity and sleep. Research examining the relationship between pre-bedtime physical activity, pain, and objective sleep is limited. This study examined whether objectively measured physical activity levels (via actigraphy), pain intensity, or their interaction are associated with polysomnographic sleep outcomes.

METHODS

Adults with fibromyalgia and insomnia complaints (n = 134, mean age = 52 yrs, SD = 12 yrs, 94% female) completed 14 days of biaxial, wrist worn actigraphy, pain ratings, and a single night of polysomnography (PSG). Average activity for intervals 9:00-12:00, 12:00-15:00, 15:00-18:00, 18:00-21:00 was computed. Multiple regressions examined whether average activity, average evening pain, or their interaction were associated with PSG outcomes: sleep onset latency (SOL), wake after sleep onset (WASO), sleep efficiency, %stage1, %stage2, %stage3, and %rapid eye movement. Analyses controlled for age, body mass index, average bedtime, time in bed, and sleep/pain medication use.

RESULTS

Greater morning actigraphic physical activity from 9:00 to 12:00 was independently associated with greater %stage 1 sleep (B = 0.01, SE = 0.00, p < .01). Greater afternoon activity from 12:00 to 15:00 independently predicted a higher WASO (p < .001). Associations between afternoon physical activity from 12:00 to 15:00 and greater %stage 1 (p < .001) were significant for at higher (~71/100), average (~52/100), but not lowest (~32/100) pain.

CONCLUSION

Greater morning and afternoon activity is associated with greater PSG sleep fragmentation and greater %stage 1 sleep in individuals with fibromyalgia and insomnia complaints, and the relationship between higher physical activity and greater %stage 1 is stronger for individuals with higher pain. Further studies examining causal pathways between physical activity, activity pacing, and sleep are warranted in fibromyalgia.

Nonimprovement in Chronic Fatigue Syndrome: Relation to Activity Patterns, Uplifts and Hassles, and Autonomic Dysfunction

OBJECTIVE

To test a model of nonimprovement in chronic fatigue syndrome (CFS) using self-report activity patterns (e.g., "push-crash"), uplifts and hassles, and a biological measure of cardiac autonomic function. Activity pattern impacts on symptoms and objective measures of autonomic and physical activity were also examined.

METHODS

This prospective study in CFS collected all data remotely, including 6 months of weekly web diaries that recorded symptom ratings, activity patterns, and hassles and uplifts. In addition, 6 months of weekly heart monitoring and 3 months of daily waking actigraphy data were collected. Improvement or nonimprovement status was assessed using semistructured interviews at the 6-month follow-up.

RESULTS

A total of 148 individuals (87.2% female) were enrolled, and 12.2% were lost to follow-up. Participants reporting nonimprovement ( n = 92), as compared with improvement ( n = 38), showed greater autonomic dysfunction (lower heart rate variability, group difference = 5.93 [SE = 2.73] milliseconds; p = .032) and lower mean intensity of behavioral uplifts (group difference = 0.14 [SE = 0.16]; p = .043), but no significant differences in any activity pattern, including push-crash, limiting activity, and healthy pacing.

CONCLUSIONS

This study provided evidence for linking patient-reported nonimprovement to a biological variable indexing autonomic dysfunction and a behavioral measure indicating a deficit in psychological uplifts. These findings suggest a possible marker of illness trajectory that could potentially advance the biomedical underpinnings of CFS.Trial Registration:ClinicalTrials.gov ID: NCT02948556.

Fatigue after neurosurgery in patients with a brain tumor: The role of autonomic dysregulation and disturbed sleep

Background Fatigue is prevalent in patients with a brain tumor and high levels of fatigue persist after neurosurgical tumor resection. The underlying mechanisms are insufficiently understood and this study examines the role of autonomic nervous system dysregulation and objective sleep characteristics in fatigue among post-surgical patients. Methods Patients undergoing craniotomy (N = 52; age 52.1 ± 15.0 years; 44% women) were evaluated at 3 months after surgery (median = 86 days). Fatigue was measured using the Multidimensional Fatigue Inventory. Autonomic nervous system indices were based on 24-h heart rate variability (HRV) analysis. Sleep parameters were measured using actigraphy: total sleep duration, efficiency, onset latency and wake after sleep onset (WASO). Data analyses of this cross-sectional study included correlation and multiple regression analysis. Results Fatigue scores were significantly elevated in tumor resection patients compared to healthy reference norms (p's < 0.05) with no differences between patients with glioma (N = 32) versus meningioma (N = 20). Associations between HRV indices and fatigue were non-significant (r values <0.16, p values > 0.25). Sleep duration was associated with physical fatigue (r = 0.35, p = 0.02), whereas WASO was associated with mental fatigue levels (r = 0.40, p = 0.006). Disturbed sleep measures were associated with HRV indices of reduced parasympathetic nervous system activity in glioma patients but not in meningioma patients. Conclusions Multiple nocturnal awakenings may result in mental fatigue and longer sleep time was associated with physical fatigue, which may reflect compensatory sleep patterns. Future intervention studies addressing sleep quality may be beneficial in treating fatigue in patients following neurosurgery for tumor resection.

The impact of mental and somatic stressors on physical activity and sedentary behaviour in adults with type 2 diabetes mellitus: a diary study

Background

Adopting an active lifestyle is key in the management of type 2 diabetes mellitus (T2DM). Nevertheless, the majority of individuals with T2DM fails to do so. Additionally, individuals with T2DM are likely to experience mental (e.g., stress) and somatic (e.g., pain) stressors. Research investigating the link between these stressors and activity levels within this group is largely lacking. Therefore, current research aimed to investigate how daily fluctuations in mental and somatic stressors predict daily levels of physical activity (PA) and sedentary behaviour among adults with T2DM.

Methods

Individuals with T2DM (N = 54) were instructed to complete a morning diary assessing mental and somatic stressors and to wear an accelerometer for 10 consecutive days. The associations between the mental and somatic stressors and participants’ levels of PA and sedentary behaviour were examined using (generalized) linear mixed effect models.

Results

Valid data were provided by 38 participants. We found no evidence that intra-individual increases in mental and somatic stressors detrimentally affected participants’ activity levels. Similarly, levels of sedentary behaviour nor levels of PA were predicted by inter-individual differences in the mental and somatic stressors.

Efficiency of an Optimized Care Organization in Fibromyalgia Patients: The From Intent to Move (FIMOUV) Study Protocol of a Randomized Controlled Trial

Introduction: Fibromyalgia (FM) is characterized by multiple symptoms including pain, fatigue, and sleep disorders, altering patient's quality of life. In the absence of effective pharmacological therapy, the last European guidelines recommend a multidisciplinary management based on exercise and education. Thus, our main objective was to measure the effectiveness of a healthcare organization offering a specific program of adapted physical activity combined with a therapeutic education program for FM patients.

Methods and Analysis: The From Intent To Move (FIMOUV) study will recruit 330 FM patients randomized into two groups: test and control. The test group will benefit from a 1-month mixed exercise training program supervised at the hospital, followed by 2 months in a community-based relay in a health-sport structure. In addition, each of the two groups will benefit from therapeutic patient education sessions. The main endpoint is the measurement of the level of physical activity by accelerometry at 1 year. The secondary endpoints concern adherence to the practice of physical activity, impact on lifestyle, state of health, and physical capacity, as well as an estimate of the budgetary impact of this management strategy.

Discussion: This interventional research will allow us to assess the evolution of behaviors in physical activity after an FM syndrome management based solely on patient education or based on a supervised and adapted practice of physical activity associated with this same therapeutic education program. It seems to be the first study evaluating the impact of its intervention on objective data for measuring physical activity and sedentary behavior via accelerometry among FM patients.

Trial registration:ClinicalTrials.gov NCT04107948.

An exploratory study of discrepancies between objective and subjective measurement of the physical activity level in female patients with chronic fatigue syndrome

OBJECTIVE

To explore the ability of a self-report activity diary to measure the physical activity level (PAL) in female patients with chronic fatigue syndrome (CFS) and whether illness-related complaints, health-related quality of life domains (HRQOL) or demographic factors are associated with discrepancies between self-reported and objectively measured PAL.

METHODS

Sixty-six patients with CFS, recruited from the chronic fatigue clinic of a university hospital, and twenty matched healthy controls wore an accelerometer (Actical) for six consecutive days and registered their activities in an activity diary in the same period. Participants' demographic data was collected and all subjects completed the CFS Symptom List (illness-related complaints) daily and Short-Form-36 (HRQOL domains) during the first and second appointment.

RESULTS

A significant, but weak association between the activity diary and Actical was present in patients with CFS (r_s = 0.376 and r_s = 0.352; p < 0.001) and a moderately strong association in healthy controls (r_s = 0.605; and r_s = 0.644; p < 0.001) between week and weekend days, respectively. A linear mixed model identified a negative association between age and the discrepancy between the self-reported and objective measure of PA in both patients with CFS and healthy controls.

CONCLUSION

The activity diary showed limited ability to register the PAL in female patients with CFS. The discrepancy between measures was not explained by illness-related complaints, HRQOL domains or demographic factors. The activity diary cannot replace objective activity monitoring measured with an accelerometer, but may provide additional information about the perceived activity.

Chronic fatigue syndrome (CFS)/Myalgic Encephalomyelitis (ME) and Fibromyalgia (FM): the foundation of a relationship

Introduction

Chronic fatigue syndrome (CFS)/Myalgic Encephalomyelitis (ME) and fibromyalgia (FM) are both debilitating syndromes with complex polysymptomatology. Early research infers that a relationship may exist even though the diagnosis provided may influence the management trajectory. In the absence of a diagnostic test and treatment, this study aims to confirm the symptoms and their severity, which may infer a relationship and influence future research.

Method

A quasi-experimental design was utilised, using Internet-based self-assessment questionnaires focusing on nine symptom areas: criteria, pain, sleep, fatigue, anxiety and depression, health-related quality of life, self-esteem and locus of control. The questionnaires used for data collection are as follows: the American Centre for Disease Control and Prevention Symptom Inventory for CFS/ME (American CDC Symptom Inventory); the American College of Rheumatology (ACR) Criteria for FM; Fibromyalgia Impact Questionnaire (FIQ); McGill Pain Questionnaire (MPQ); Multidimensional Fatigue Inventory (MFI); Pittsburgh Sleep Quality Index (PSQI); Health-Related Quality of Life SF-36 V2 (HRQoL SF-36 V2); Hospital Anxiety and Depression Scale (HADS); Multidimensional Health Locus of Control (MHLOC) and the Rosenberg Self-Esteem Scale (RSES).

Setting and participants

Participants were recruited from two distinct community groups, namely CFS/ME (n = 101) and FM (n = 107). Participants were male and female aged 17 (CFS/ME mean age 45.5 years; FM mean age 47.2 years).

Results

All participants in the CFS/ME and FM groups satisfied the requirements of their individual criteria. Results confirmed that both groups experienced the debilitating symptoms measured, with the exception of anxiety and depression, impacting on their quality of life. Results suggest a relationship between CFS/ME and FM, indicating the requirement for future research.

Exploratory study into the relationship between the symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM) using a quasiexperimental design

OBJECTIVE

To explore the relationship between symptoms of chronic fatigue syndrome (CFS)/myalgic encephalomyelitis (ME) and fibromyalgia (FM). The hypothesis predicated that there would be no significant differences between the group's symptom experience.

DESIGN

A quasiexperimental design. Structural equation modelling (SEM) and invariance testing.

PARTICIPANTS

Males (M) and females (F) >16 with a confirmed diagnosis of CFS/ME or FM by a general practitioner or specialist. CFS/ME (n=101, F: n=86, M: n=15, mean (M) age M=45.5 years). FM (n=107, F: n=95, M: n=12, M=47.2 years).

OUTCOME MEASURES

Diagnostic criteria: the American Centers for Disease Control and Prevention (CDC) for CFS/ME and the American College of Rheumatology (ACR) criteria for FM. Additional symptom questionnaires measuring: pain, sleep quality, fatigue, quality of life, anxiety and depression, locus of control and self-esteem.

RESULTS

Invariance was confirmed with the exception of the American CDC Symptom Inventory, Fibromyalgia Impact Questionnaire and Hospital Anxiety and Depression Scale (p<0.05) based on five questions. Consequently, it was erroneous to conclude differences. Therefore, the Syndrome Model was created. SEM could not have tested the ACR previously, as it comprised a single data point. Thus, it was combined with these three questionnaires, increasing the data points, to create this new measurable model. Results confirmed no significant differences between groups (p=0.07 (p<0.05)).

CONCLUSION

Participants responded in a similar manner to the questionnaire, confirming the same symptom experience. It is important to consider this in context with differing criteria and management guidelines, as this may influence diagnosis and the trajectory of patient's management. With the biomedical cause currently unclear, it is the symptom experience and the impact on quality of life that is important. These findings are meaningful for patients, clinicians and policy development and support the requirement for future research.

Preliminary Evidence for the Fibromyalgia Integrative Training Program (FIT Teens) Improving Strength and Movement Biomechanics in Juvenile Fibromyalgia: Secondary Analysis and Results from a Pilot Randomized Clinical Trial

OBJECTIVES

Current therapies for juvenile fibromyalgia (JFM), such as cognitive-behavioral therapy (CBT), improve pain coping but are less effective for pain reduction or engagement in physical activity. The Fibromyalgia Integrative Training for Teens (FIT Teens) program combines CBT with specialized neuromuscular exercise training for adolescents with JFM. The current investigation examined the effects of FIT Teens versus CBT on secondary outcomes of strength and functional biomechanics, utilizing 3D Motion capture technology. This study aimed to explore improvements in strength and biomechanics in both a CBT-only group and the FIT Teens intervention.

MATERIALS AND METHODS

Forty adolescents with JFM (12 to 18 y) were randomized to an 8-week, group-based protocol of either FIT Teens or CBT only. Assessments occurred pretreatment and posttreatment. Hip and knee strength were assessed with dynamometry, dynamic postural stability was measured using the Star Excursion Balance Test, and movement biomechanics were assessed with 3D motion analyses during a drop vertical jump (DVJ) task.

RESULTS

The FIT Teens group exhibited improvements in hip abduction strength and greater external hip rotation during the DVJ task. Some differences between the FIT Teens and CBT groups were observed in peak hip internal moment in the transverse plane. Decreased hip adduction during the DVJ was also observed in the FIT Teens group.

DISCUSSION

Results suggest that the FIT Teens program shows promise in improving hip abduction strength and body biomechanics, indicating improvements in stability during functional movements. These improvements may facilitate ability to initiate and maintain regular physical activity in youth with widespread musculoskeletal pain.

Associations between objective afternoon and evening physical activity and objective sleep in patients with fibromyalgia and insomnia

Patients with fibromyalgia (FM) suffer from chronic pain, which limits physical activity and is associated with disturbed sleep. However, the relationship between physical activity, pain and sleep is unclear in these patients. This study examined whether actigraphic (Actiwatch-2, Philips Respironics) afternoon and evening activity and pain are associated with actigraphic sleep. Adults with FM and insomnia complaints (n = 160, mean age [M_age ] = 52, SD = 12, 94% female) completed 14 days of actigraphy. Activity levels (i.e., activity counts per minute) were recorded, and average afternoon/evening activity for intervals 12:00-3:00 PM, 3:00-6:00 PM and 6:00-9:00 PM was computed. Multiple linear regressions examined whether afternoon/evening activity, pain (daily evening diaries from 0 [no pain sensation] to 100 [most intense pain imaginable]), or their interaction, predicted sleep onset latency (SOL), wake time after sleep onset (WASO), total sleep time (TST) and sleep efficiency (SE). Greater afternoon activity was independently associated with lower SE (B = -0.08, p < .001), lower TST (β = -0.36, standard error [SE] = 0.06, p < .001) and longer WASO (B = 0.34, p < .001). Greater early evening activity was independently associated with lower SE (B = -0.06, p < .001), lower TST (β = -0.26, SE = 0.06, p < .001) and longer WASO (B = 0.23, p < .001). Self-reported pain intensity interacted with afternoon and early evening physical activity, such that associations between higher activity and lower SE were stronger for individuals reporting higher pain. Late evening activity was not associated with sleep outcomes. Results suggest that in FM, increased afternoon and early evening physical activity is associated with sleep disturbance, and this relationship is stronger in individuals with higher pain.

Lower Fatigue in Fit and Positive Women with Fibromyalgia: The al-Ándalus Project

OBJECTIVE

To analyze 1) the independent association of physical fitness, positive affect, and negative affect with the different dimensions of fatigue (general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue) and 2) whether the interactions of physical fitness, positive affect, and negative affect were associated with fatigue over and above the independent association.

DESIGN

Cross-sectional study in 420 women with fibromyalgia.

SETTING

Fibromyalgia associations from southern Spain.

METHODS

Physical fitness was measured by performance-based tests, and questionnaires were used to measure positive affect, negative affect, and different dimensions of fatigue (general fatigue, physical fatigue, reduced activity, reduced motivation, and mental fatigue). Age, body mass index, and current pain level were included as potential confounders in all analyses.

RESULTS

Physical fitness was independently associated with general fatigue, physical fatigue, and reduced activity (all P ≤ 0.02). Positive affect was independently associated with all fatigue dimensions (all P < 0.001). Negative affect was independently associated with general fatigue, physical fatigue, reduced motivation, and mental fatigue (all P ≤ 0.04). The interaction of overall physical fitness and positive affect was related to general fatigue and physical fatigue (all P ≤ 0.02). Women with fibromyalgia with higher levels of overall physical fitness and positive affect showed the lowest general fatigue and physical fatigue.

CONCLUSIONS

In women with fibromyalgia, positive affect was independently and consistently associated with all dimensions of fatigue. The combination of higher levels of overall physical fitness and positive affect might serve as a buffer against general and physical fatigue in women with fibromyalgia.

Ambulatory Assessment for Physical Activity Research: State of the Science, Best Practices and Future Directions

Technological and digital progress benefits physical activity (PA) research. Here we compiled expert knowledge on how Ambulatory Assessment (AA) is utilized to advance PA research, i.e., we present results of the 2nd International CAPA Workshop 2019 "Physical Activity Assessment - State of the Science, Best Practices, Future Directions" where invited researchers with experience in PA assessment, evaluation, technology and application participated. First, we provide readers with the state of the AA science, then we give best practice recommendations on how to measure PA via AA and shed light on methodological frontiers, and we furthermore discuss future directions. AA encompasses a class of methods that allows the study of PA and its behavioral, biological and physiological correlates as they unfold in everyday life. AA includes monitoring of movement (e.g., via accelerometry), physiological function (e.g., via mobile electrocardiogram), contextual information (e.g., via geolocation-tracking), and ecological momentary assessment (EMA; e.g., electronic diaries) to capture self-reported information. The strengths of AA are data assessment that near realtime, which minimizes retrospective biases in real-world settings, consequentially enabling ecological valid findings. Importantly, AA enables multiple assessments across time within subjects resulting in intensive longitudinal data (ILD), which allows unraveling within-person determinants of PA in everyday life. In this paper, we show how AA methods such as triggered e-diaries and geolocation-tracking can be used to measure PA and its correlates, and furthermore how these findings may translate into real-life interventions. In sum, AA provides numerous possibilities for PA research, especially the opportunity to tackle within- subject antecedents, concomitants, and consequences of PA as they unfold in everyday life. In-depth insights on determinants of PA could help us design and deliver impactful interventions in real-world contexts, thus enabling us to solve critical health issues in the 21st century such as insufficient PA and high levels of sedentary behavior.

Validation of the Severity of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome by Other Measures than History: Activity Bracelet, Cardiopulmonary Exercise Testing and a Validated Activity Questionnaire: SF-36

Introduction: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe and disabling chronic disease. Grading patient’s symptom and disease severity for comparison and therapeutic decision-making is necessary. Clinical grading that depends on patient self-report is subject to inter-individual variability. Having more objective measures to grade and confirm clinical grading would be desirable. Therefore, the aim of this study was to validate the clinical severity grading that has been proposed by the authors of the ME International Consensus Criteria (ICC) using more standardized measures like questionnaires, and objective measures such as physical activity tracking and cardiopulmonary exercise testing. Methods and results: The clinical database of a subspecialty ME/CFS clinic was searched for patients who had completed the SF 36 questionnaire, worn a Sensewear^TM armband for five days, and undergone a cardiopulmonary exercise test. Only patients who completed all three investigations within 3 months from each other—to improve the likelihood of stable disease—were included in the analysis. Two-hundred-eighty-nine patients were analyzed: 121 were graded as mild, 98 as moderate and 70 as having severe disease. The mean (SD) physical activity subscale of the SF-36 was 70 (11) for mild, 43 (8) for moderate and 15 (10) for severe ME/CFS patients. The mean (SD) number of steps per day was 8235 (1004) for mild, 5195 (1231) for moderate and 2031 (824) for severe disease. The mean (SD) percent predicted oxygen consumption at the ventilatory threshold was 47 (11)% for mild, 38 (7)% for moderate and 30 (7)% for severe disease. The percent peak oxygen consumption was 90 (14)% for mild, 64 (8)% for moderate and 48 (9)% for severe disease. All comparisons were p < 0.0001. Conclusion: This study confirms the validity of the ICC severity grading. Grading assigned by clinicians on the basis of patient self-report created groups that differed significantly on measures of activity using the SF-36 physical function subscale and objective measures of steps per day and exercise capacity. There was variability in function within severity grading groups, so grading based on self-report can be strengthened by the use of these supplementary measures.

Patterns of daytime physical activity in patients with chronic fatigue syndrome

OBJECTIVES

To classify patients with chronic fatigue syndrome (CFS) by pattern of physical activity and determine the clinical associations of each type.

METHODS

579 out of 641 participants with CFS from the PACE (Pacing, graded Activity, Cognitive behavioural therapy: a randomised Evaluation) trial wore an Actiwatch (accelerometer) for between 3 and 7 days before any trial treatments, which provided a measure of physical activity. Participants' activity was categorised into one of four patterns (pervasively inactive, pervasively active, boom and bust, or indeterminate) primarily using a priori definitions of activity. Clinical associations were sought with each group using an exploratory logistic regression with the indeterminate activity group being the reference group.

RESULTS

124 (21%) of the participants were classified as pervasively inactive, 65 (11%) as pervasively active, 172 (30%) showed a 'boom and bust' pattern of activity, and 218 (38%) had an indeterminate pattern. Pervasively inactive patients were more physically disabled, those in the pervasively active group were more anxious, and those in the boom and bust group had more sleep disturbance.

CONCLUSION

We were able to classify patients with CFS into groups by their daytime activity pattern. The different patterns of activity were associated with important clinical variables, suggesting that they might be helpful in determining prognosis and targeting treatments. These associations need replication.

Seasonality in pain, sleep and mental distress in patients with chronic musculoskeletal pain at latitude 69° N

Seasonality is evident in several aspects of human health and behavior, whereas seasonality in chronic pain is less well studied. We examined seasonal variation in pain severity and pain dissemination, as well as in pain-associated conditions, such as sleep impairment, sleep timing, mental distress, fatigue and physical activity. We also examined if any of these associated conditions moderated the seasonality in pain. This prospective study was conducted in the subarctic municipality of Tromsø, Norway (69º North), on a sample of patients with chronic musculoskeletal pain (N = 56). Data were collected with self-report questionnaires and objective actigraphy measures (7 days) twice: winter and summer. Mixed linear regression models were fitted. A modest seasonality effect was observed in pain severity (highest in summer), but not in pain dissemination. Seasonality with increased physical activity and delayed sleep timing in the summer was also present. The remaining pain-associated self-report or objective measures indicated no seasonality. The season-pain association was not significantly moderated by any of the pain-associated conditions. Previous studies on healthy individuals residing in polar areas have suggested an opposite seasonal effect with delay of the sleep-wake rhythm in winter. Our results based on a clinical sample thus represent a novel finding that needs to be examined further with regard to seasonal circadian entrainment and alignment in pain populations. These results may have clinical value for the treatment of patients with musculoskeletal pain as seasonality may require seasonal adjustments of pain treatment strategies.

P2X4 Receptors on Muscle Macrophages Are Required for Development of Hyperalgesia in an Animal Model of Activity-Induced Muscle Pain

Activity-induced pain is common in those with chronic musculoskeletal pain and limits participation in daily activities and exercise. Our laboratory developed a model of activity-induced pain and shows that depletion of muscle macrophages prevents development of hyperalgesia. Adenosine triphosphate (ATP) is released from fatiguing muscle and activates purinergic receptors (P2X), and P2X4 receptors are expressed on macrophages. We hypothesized that exercise releases ATP to activate P2X4 receptors on muscle macrophages, which subsequently release interleukin-1β (IL-1β) to produce hyperalgesia. In an animal model of activity-induced pain, using male and female C57BL6/J mice, we show increased expression of P2X4 on muscle macrophages, and blockade of P2X4 receptors in muscle prevented development of hyperalgesia. Using a lentivirus expressing an artificial micro-RNA to P2X4 under the control of a CD68 promoter, we decreased expression of P2X4 mRNA in cultured macrophages, decreased expression of P2X4 protein in muscle macrophages in vivo, and prevented development of activity-induced hyperalgesia. We further show that macrophages primed with LPS differentially released IL-1β when treated with ATP in neutral or acidic pH. Lastly, blockade of IL-1β in muscle prevented development of hyperalgesia in this model. Thus, our data suggest that P2X4 receptors could be a valid pharmacological target to control activity-induced muscle pain experienced by patients with chronic musculoskeletal pain.

Assessing Physical Activity and Sleep in Axial Spondyloarthritis: Measuring the Gap

Patients with axial spondyloarthritis (axSpA) frequently report pain, stiffness, fatigue, and sleep problems, which may lead to impaired physical activity. The majority of reported-on measures evaluating physical activity and sleep disturbance in axSpA are self-reported questionnaires, which can be impacted by patient recall (reporting bias). One objective measure, polysomnography, has been employed to evaluate sleep in patients with axSpA; however, it is an intrusive measure and cannot be used over the long term. More convenient objective measures are therefore needed to allow for the long-term assessment of both sleep and physical activity in patients' daily lives. Wearable technology that utilizes actigraphy is increasingly being used for the objective measurement of physical activity and sleep in various therapy areas, as it is unintrusive and suitable for continuous tracking to allow longitudinal assessment. Actigraphy characterizes sleep disruption as restless movement while sleeping, which is particularly useful when studying conditions such as axSpA in which chronic pain and discomfort due to stiffness may be evident. Studies have also shown that actigraphy can effectively assess the impact of disease on physical activity. More research is needed to establish the usefulness of objective monitoring of sleep and physical activity specifically in axSpA patients over time. This review summarizes the current perspectives on physical activity and sleep quality in patients with axSpA, and the possible role of actigraphy in the future to more accurately evaluate the impact of treatment interventions on sleep and physical activity in axSpA.Funding: Novartis Pharmaceuticals Corporation.Plain Language Summary: Plain language summary available for this article.

Effectiveness of resistance exercise in functional fitness in women with primary Sjögren's syndrome: randomized clinical trial

Objective: The purpose of this study was to analyse the effectiveness of resistance exercise in functional fitness in women with primary Sjögren's syndrome (pSS).Method: This is a randomized controlled clinical trial with 51 volunteers: 26 allocated to the exercise group (GEX) and 25 to the control group. The GEX underwent a supervised resistance-training programme for 16 weeks, with two sessions per week. The outcomes measured were: functional capacity (FC), by the Fullerton Functional Fitness Test; Daily Motor Activity Index (DMAI), evaluated by an actigraph; disease activity, by the ESSDAI; and quality of life, by the 36-item Short Form Health Survey (SF-36). The evaluations were performed by a blind evaluator at baseline (TØ) and after 16 weeks (T16wk).Results: In the GEX, all FC parameters demonstrated improvement, except for the upper limb flexibility test (p = 0.866): upper and lower limb strength, flexibility, aerobic capacity, and agility (all p < 0.01). A similar situation occurred in the SF-36, where all domains demonstrated improvement except for the emotional aspect (p = 0.710): FC, physical aspects limitation, general health status, vitality, social aspects, and mental health (all p < 0.01). The DMAI (p = 0.2) and EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) (p = 0.284) did not change. No significant improvement was observed in the control group.Conclusion: The supervised resistance exercise programme did not worsen the DMAI or disease activity, demonstrating the safety of the intervention, and was effective in improving FC and quality of life in women with pSS.Registry identifier (clinical trials.gov): NCT03130062.

Measuring Physical Activity in Spinal Cord Injury Using Wrist-Worn Accelerometers

OBJECTIVE

Our objective was to evaluate interunit agreement and construct validity of two activity monitors (Actiwatch Score and PRO-Diary) in people with and without spinal cord injury.

METHOD

Thirty-eight participants (19 with spinal cord injury; 19 age- and sex-matched controls; mean age = 49 yr) wore both monitors and completed tasks during one visit ranging in physical intensity. To compare activity by group and monitor, we conducted t tests. We assessed interunit agreement using intraclass correlations and Bland-Altman plots.

RESULTS

Both monitors demonstrated significantly different increasing physical activity levels with higher intensity tasks. Participants with spinal cord injury had similar activity counts within tasks compared with controls except for walking-wheeling. Agreement was high between monitors across tasks (interclass correlation coefficients = .78-.97).

CONCLUSION

Both monitors demonstrated good construct validity for measuring physical activity across activities and high agreement. Either monitor is appropriate to examine physical activity patterns in people with spinal cord injury.

Sarcopenia in osteoarthritis and rheumatoid arthritis: The association with self-reported fatigue, physical function and obesity

AIM

To determine if there is an association between sarcopenia, physical function and self-reported fatigue in osteoarthritis (OA) and rheumatoid arthritis (RA).

METHODS

A cross-sectional analysis of measurements from a cohort of 157 participants with OA or RA was performed. The relationship between muscle mass (appendicular muscle index (AMI)), physical function (timed up and go, 30-seconds sit-to-stand test, 40-meter fast-paced walk test and grip-strength) and two fatigue measures (Multidimensional Assessment of Fatigue (MAF) and a fatigue Visual Analogue Scale (VAS)) was explored using hierarchical linear regression or logistic regression with established AMI cut-offs for sarcopenia.

RESULTS

There were no significant differences for perceived fatigue-related variables between OA or RA sarcopenic or non-sarcopenic participants. Participants with OA had worse physical function (TUG; P = 0.029, STS; P = 0.004, WS; P = 0.003), but participants with RA had lower grip strength (P<0.001). The RA group had higher CRP (P = 0.006), were more likely to receive glucocorticoids (P<0.001), and experienced worse fatigue (P = 0.050). The hierarchical multiple regression showed that self-reported fatigue (VAS/MAF-distress) had a significant but weak association with AMI in RA. Participants with higher percentage body fat had a significantly stronger association with sarcopenia in both OA and RA.

CONCLUSION

Sarcopenia, when assessed by AMI, does not appear to be strongly associated with self-reported fatigue or physical function in participants with either OA or RA. Higher body fat had a moderately strong association with sarcopenia in this cross-sectional study, suggesting that body composition may be an important factor in the health of patients with longstanding OA or RA.

Associations Between Bone Mass in Women With Fibromyalgia and Widespread Pressure Pain Hypersensitivity, Tenderness, Perceived Pain Level, and Disability

This study aimed to evaluate the impact of fibromyalgia syndrome (FMS) on bone mass assessed by calcaneal quantitative ultrasound (QUS) in pre- and postmenopausal women and determine whether there are associations between bone status and pressure pain thresholds (PPTs), tender point counts (TPCs), self-reported global pain, or disease severity. Ninety-five women with a diagnosis of FMS and 108 healthy controls matched on menopause status were included in this cross-sectional study. PPT and TPC were measured by algometry pressure. Self-reported global pain and disease severity were evaluated by Visual Analogue Scale and Fibromyalgia Impact Questionnaire, respectively. Bone mass was assessed with calcaneus QUS. Broadband ultrasound attenuation (BUA; dB/MHz) and speed of sound (SOS; m/s) were significantly lower in the FMS patients compared with controls ( p = .027 and p = .003, respectively). Linear regression analysis revealed that all PPTs were significantly associated with the BUA parameter after adjustments for body mass index (BMI), menopause status, and physical activity in women with FMS ( p < .05). TPC was also significantly associated with BUA after adjustments for covariables (β = .241, 95% confidence interval [0.333, 3.754], p = .020). No significant differences were found between any QUS measurements and global pain or disease severity. Calcaneal BUA and SOS values were lower in women with FMS compared to healthy controls, and decreased pain thresholds and higher TPCs were associated with lower calcaneal BUA values. Low pain thresholds might be independent predictors for low bone mass in FMS women.

Inferring Physical Function From Wearable Activity Monitors: Analysis of Free-Living Activity Data From Patients With Knee Osteoarthritis

Background

Clinical assessments for physical function do not objectively quantify routine daily activities. Wearable activity monitors (WAMs) enable objective measurement of daily activities, but it remains unclear how these map to clinically measured physical function measures.

Objective

This study aims to derive a representation of physical function from daily measurements of free-living activity obtained through a WAM. In addition, we evaluate our derived measure against objectively measured function using an ordinal classification setup.

Methods

We defined function profiles representing average time spent in a set of pattern classes over consecutive days. We constructed a function profile using minute-level activity data from a WAM available from the Osteoarthritis Initiative. Using the function profile as input, we trained statistical models that classified subjects into quartiles of objective measurements of physical function as measured through the 400-m walk test, 20-m walk test, and 5 times sit-stand test. Furthermore, we evaluated model performance on held-out data.

Results

The function profile derived from minute-level activity data can accurately predict physical performance as measured through clinical assessments. Using held-out data, the Goodman-Kruskal Gamma statistic obtained in classifying performance values in the first quartile, interquartile range, and the fourth quartile was 0.62, 0.53, and 0.51 for the 400-m walk, 20-m walk, and 5 times sit-stand tests, respectively.

Conclusions

Function profiles accurately represent physical function, as demonstrated by the relationship between the profiles and clinically measured physical performance. The estimation of physical performance through function profiles derived from free-living activity data may enable remote functional monitoring of patients.

Physical Activity and Sleep in Chronic Fatigue Syndrome and Fibromyalgia Syndrome: Associations with Symptom Severity in the General Population Cohort LifeLines

Objective

The aim of the current study was to compare physical activity and sleep duration between patients with chronic fatigue syndrome (CFS), patients with fibromyalgia syndrome (FMS), and controls and to examine the association between physical activity level and sleep duration with symptom severity within these patient groups.

Methods

This study used data of LifeLines, a general population cohort in which 1.0% (n=943, 63.7% female, age 44.9 (SD 11.6) years) reported CFS, 3.0% (n=2,714; 91.6% female; age 48.4 (SD 10.7) years) reported FMS, and 95.7% (n=87,532; 57.9% female; age 44.3 (SD 12.4) years) reported neither CFS nor FMS. Physical activity, sleep duration, and symptom severity were assessed by questionnaires and analysed using ANCOVA and regression analyses, adjusted for age, sex, body mass index, smoking, and educational level.

Results

Patients with CFS and FMS had significantly lower physical activity scores (8834 ± 5967 and 8813 ± 5549 MET ∗ minutes) than controls (9541 ± 5533; p < 0.001). Patients with CFS had the longest sleep duration (466 ± 86 minutes) compared to patients with FMS and controls (450 ± 67 and 446 ± 56; p < 0.001). A linear association between physical activity, sleep duration, and symptom severity was only found in controls, in whom higher physical total activity scores and longer sleep duration were associated with a lower symptom severity. In contrast, quadratic associations were found in all groups: both relatively low and high physical activity scores and relatively short and long sleep duration were associated with higher symptom severity in CFS, FMS, and controls.

Conclusion

This study indicates that patients with CFS or FMS sleep longer and are less physically active than controls on average. Both low and high levels of physical activity and short and long sleep duration are associated with higher symptom severity, suggesting the importance of patient-tailored treatment.

Physical activity is related to function and fatigue but not pain in women with fibromyalgia: baseline analyses from the Fibromyalgia Activity Study with TENS (FAST)

BACKGROUND

Although exercise is an effective treatment for fibromyalgia, the relationships between lifestyle physical activity and multiple symptomology domains of fibromyalgia are not clear. Thus, the purpose of this study was to comprehensively examine the relationships between lifestyle physical activity with multiple outcome domains in women with fibromyalgia, including pain, fatigue, function, pain-related psychological constructs, and quality of life.

METHODS

Women (N = 171), aged 20 to 70 years, diagnosed with fibromyalgia, recruited from an ongoing two-site clinical trial were included in this prespecified subgroup analysis of baseline data. Physical activity was assessed using self-report and accelerometry. Symptomology was assessed using questionnaires of perceived physical function, quality of life, fatigue, pain intensity and interference, disease impact, pain catastrophizing, and fear of movement. In addition, quantitative sensory testing of pain sensitivity and performance-based physical function were assessed. Correlation coefficients, regression analyses and between-group differences in symptomology by activity level were assessed, controlling for age and body mass index (BMI).

RESULTS

Lifestyle physical activity was most closely associated with select measures of physical function and fatigue, regardless of age and BMI. Those who performed the lowest levels of lifestyle physical activity had poorer functional outcomes and greater fatigue than those with higher physical activity participation. No relationships between lifestyle physical activity and pain, pain sensitivity, or pain-related psychological constructs were observed.

CONCLUSIONS

Lifestyle physical activity is not equally related to all aspects of fibromyalgia symptomology. Lifestyle physical activity levels have the strongest correlations with function, physical quality of life, and movement fatigue in women with fibromyalgia. No relationships between lifestyle physical activity and pain, pain sensitivity, or psychological constructs were observed. These data suggest that physical activity levels are more likely to affect function and fatigue, but have negligible relationships with pain and pain-related psychological constructs, in women with fibromyalgia.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01888640 . Registered on 28 June 2013.

Ecological Momentary Assessment Methodology in Chronic Pain Research: A Systematic Review

Self-reported pain intensity assessments are central to chronic pain research. Ecological momentary assessment (EMA) methodologies are uniquely positioned to collect these data, and are indeed being used in the field. However, EMA protocols are complex, and many decisions are necessary in the design of EMA research studies. A systematic literature review identified 105 articles drawing from 62 quantitative EMA research projects examining pain intensity in adult chronic pain patients. Study characteristics were tabulated to summarize and describe the use of EMA, with an emphasis placed on various dimensions of decision-making involved in executing EMA methodologies. Most identified studies considered within-person relationships between pain and other variables, and a few examined interventions on chronic pain. There was a trend toward the use of smartphones as EMA data collection devices more recently, and completion rates were not reported in nearly one third of studies. Pain intensity items varied widely with respect to number of scale points, anchor labels, and length of reporting period; most used numeric rating scales. Recommendations are provided for reporting to improve reproducibility, comparability, and interpretation of results, and for opportunities to clarify the importance of design decisions.

PERSPECTIVE

Studies that use EMA methodologies to assess pain intensity are heterogeneous. Aspects of protocol design, including data input modality and pain item construction, have the potential to influence the data collected. Thorough reporting on design features and completion rates therefore facilitates reproducibility, comparability, and interpretation of study results.

Differences in daily objective physical activity and sedentary time between women with self-reported fibromyalgia and controls: results from the Canadian health measures survey

Physical activity and sedentary behaviors are important modifiable factors that influence health and quality of life in women with fibromyalgia. The purpose of this study was to compare objectively assessed physical activity and sedentary time in women self-reporting fibromyalgia with a control group. Data were drawn from the Canadian Health Measures Survey cycles 1, 2, and 3 conducted by Statistics Canada. We included women aged 18 to 79 years with complete accelerometer data. We performed one-way analyses of covariance (adjusted-for socio-demographic and health factors) to determine mean differences in physical activity and sedentary variables (minutes per day of moderate and vigorous physical activity, light physical activity, sedentary and daily steps) between women with and without fibromyalgia. In total, 4132 participants were included. A cross-sectional weighted analysis indicated that 3.1% of participants self-reported a diagnosis of fibromyalgia. Participants with fibromyalgia spent less time than controls engaged in moderate and vigorous physical activity (M = 19.2 min/day (SE = 0.7) versus M = 9.1 min/day (SE = 1.2), p = 0.03, η² = 0.01). No significant differences were found for daily time spent in light physical activity, sedentary activities, and number of steps. Women participants with self-reported fibromyalgia spent significantly less time in moderate and vigorous physical activity than control. Physical activity promotion interventions for women with self-reported fibromyalgia should, as a priority, target physical activities with moderate to vigorous intensity.

Activity rhythms and clinical correlates in fibromyalgia

The primary aim of this study was to evaluate activity rhythms in fibromyalgia syndrome (FMS) and their association with FMS-related symptoms. We hypothesized that stronger and more consistent activity rhythms would be associated with reduced symptom severity and presentation in FMS. Two hundred ninety-two patients with FMS (mean age = 45.1 ± 11.1; 272 women) provided a 7-day actigraphy recording and responses to questionnaires addressing degree of pain, fatigue, mood, and physical impairment. Using a simple cosine model, we extracted Amplitude (activity range), Phi (time at maximum), Mesor (mean activity), and their variabilities (across days) from each participant's actigraphy. The clinical and actigraphic measures were operationally independent. There was a significant canonical relationship between activity rhythm parameters and clinical FMS measures (r = 0.376, R = 0.14, P < 0.001). The set of Mesor, Amplitude, and Phi activity parameters remained associated with clinical measures when controlled statistically for both demographics and activity variability (P < 0.001). Each activity parameter provided unique discrimination of the clinical set by multivariate test (P = 0.003, 0.018, and 0.007 for Amplitude, Phi, and Mesor, respectively). These results revealed that better pain, fatigue, mood, physical impairment, and sleep outcomes were associated with higher activity range and more rhythmicity (Amplitude), increased mean activity (Mesor), and with earlier timing of peak activity (Phi). Exploratory analyses revealed significantly worse sleep for individuals with low Amplitude and more delayed Phi.

Controlled, cross-sectional, multi-center study of physical capacity and associated factors in women with fibromyalgia

Background

Health and physical capacity are commonly associated with disease, age, and socioeconomic factors. The primary objective of this study was to investigate the degree to which physical capacity, defined as muscle strength and walking ability, is decreased in women with fibromyalgia (FM), as compared to healthy women, who are matched for age and level of education. The secondary aim was to investigate whether muscle strength and walking ability are associated with age, symptom duration, activity limitations and, Body Mass Index (BMI) in women with FM and control subjects.

Methods

This controlled, cross-sectional, multi-center study comprised 118 women with FM and 93 age- and education-level-matched healthy women. The outcome measures were isometric knee-extension force, isometric elbow-flexion force, isometric hand-grip force, and walking ability. Differences between the groups were calculated, and for the women with FM analyses of correlations between the measures of physical capacity and variables were performed.

Results

The women with FM showed 20% (p < 0.001) lower isometric knee-extension force, 36% (p < 0.001) lower isometric elbow-flexion force, 34% (p < 0.001) lower isometric hand-grip force, and 16% lower walking ability (p < 0.001), as compared to the healthy controls. All measures of muscle strength in women with FM showed significant weak to moderate relationship to symptom duration (r_s = − 0.23–0.32) and walking ability (r_s = 0.25–0.36). Isometric knee-extension force correlated with activity limitations, as measured using the SF-36 Physical function subscale (r_s=0.23, p = 0.011).

Conclusions

Physical capacity was considerably decreased in the women with FM, as compared to the age- and education-level-matched control group. All measures of physical capacity showed a significant association with symptom duration. Knee-extension force and walking ability were significantly associated with activity limitations, age, and BMI. It seems important to address this problem and to target interventions to prevent decline in muscle strength. Assessments of muscle strength and walking ability are easy to administer and should be routinely carried out in the clinical setting for women with FM.

Trial registration

ClinicalTrials.gov identification number: NCT01226784, Oct 21, 2010.

Experiences and attitudes about physical activity and exercise in patients with chronic pain: a qualitative interview study

Purpose

The purpose of this study was to describe how patients with chronic pain experience physical activity and exercise (PA&E).

Method

This qualitative interview study included 16 women and two men suffering from chronic pain and referred to a multimodal pain rehabilitation program. Semi-structured interviews were conducted and qualitative content analysis was used to analyze the interviews.

Results

One main theme emerged: "To overcome obstacles and to seize opportunities to be physically active despite chronic pain." This main theme was abstracted from five themes: "Valuing a life with physical activity," "Physical activity and exercise - before and after pain," "A struggle - difficulties and challenges," "The enabling of physical activity," and "In need of continuous and active support."

Conclusion

Although these participants valued PA&E, they seldom achieved desirable levels, and performance of PA&E was undermined by difficulties and failure. The discrepancy between the intention to perform physical activity and the physical activity accomplished could be related to motivation, self-efficacy, and action control. The participants desired high-quality interaction with healthcare providers. The findings can be applied to chronic pain rehabilitation that uses PA&E as treatment.

All Fatigue is Not Created Equal: The Association of Fatigue and Its Subtypes on Pain Interference in Orofacial Pain

OBJECTIVES

Fatigue is known to be a pathway through which depression, psychological distress, pain intensity, and sleep disturbance influence pain interference, but the independent effects of fatigue on pain interference after controlling for these variables remains unknown. In addition, no study to date has tested whether fatigue subtypes of general fatigue, mental fatigue, emotional fatigue, physical fatigue, or vigor differentially predict pain interference.

METHODS

The current study tested these associations using archival medical data of 2133 chronic orofacial pain patients, who completed a battery of psychological questionnaires at the time of their first appointment at an orofacial pain clinic.

RESULTS

Hierarchical linear regression analysis revealed that after controlling for depression, psychological distress, sleep disturbance, pain intensity, and demographic variables, fatigue predicted higher pain interference (B=0.70, SE=0.17, P<0.001, η=0.01). Physical fatigue (B=1.70, SE=0.48, P<0.001, η=0.01) and vigor (B=-3.24, SE=0.47, P<0.001, η=0.03) were independently associated with pain interference after controlling for the aforementioned variables.

DISCUSSION

The findings suggest that fatigue is an important independent predictor of pain interference and not merely a mediator. These findings also suggest that not all fatigue is created equal. Interventions aimed at reducing pain interference should target specific fatigue symptoms of physical fatigue and vigor. Future research investigating the independent associations of fatigue subtypes on pain outcomes may help clarify the nature of the interrelationships between pain and fatigue.

The Complex Relationship between Pain Intensity and Physical Functioning in Fibromyalgia: The Mediating Role of Depression

PURPOSE

Fibromyalgia (FM) is typically associated with the experience of diffuse pain and physical impairment. Depression also commonly co-exists in patients with FM, and has been correlated with pain intensity and physical functioning. Previous research suggests an association between pain intensity and physical functioning; however, the direct causal relationship between improvements in pain intensity and in functioning is not observed in many FM patients. This may suggest that another factor such as depression is mediating this relationship. The present work examined mediating role of depression.

METHODS

216 patients with FM completed measures of pain intensity, depression, and physical function as part of a larger longitudinal study. Assessments were completed at baseline, 12, 24, and 36 weeks.

RESULTS

Longitudinal mediational analyses indicated that depression is a partial mediator of the relationship between pain intensity and physical functioning at all four assessment points. Beta coefficients for the path from pain to physical functioning ranged from 0.18 - 0.36, with attenuated path coefficients ranging from 0.03 - 0.08, still showing significant but decreased associations when depression was added as a mediator.

CONCLUSIONS

Clinical implication includes the importance of treating co-morbid depression in patients with fibromyalgia early in the course of treatment to prevent engagement in the cycle of disability.

Preliminary Outcomes of a Cross-Site Cognitive-Behavioral and Neuromuscular Integrative Training Intervention for Juvenile Fibromyalgia

OBJECTIVE

Cognitive-behavioral therapy (CBT) is effective in reducing disability among youth with juvenile fibromyalgia (FM); however, engagement in moderate to vigorous physical activity remains poor, even after CBT. The purpose of this study was to evaluate the feasibility and preliminary outcomes of an innovative program combining CBT with specialized neuromuscular exercise: the Fibromyalgia Integrative Training for Teens (FIT Teens) program.

METHODS

Adolescents with juvenile FM (n = 22, all female, ages 12-18 years) from 2 urban children's hospitals participated in the 8-week FIT Teens intervention. Participants completed measures of pain intensity, functional disability, depressive symptoms, pain catastrophizing, fear of movement, and readiness to change at baseline and after the intervention.

RESULTS

The feasibility of the intervention across 2 sites was documented, including high retention rates (80%). Participants showed significant decreases in functional disability (P < 0.05), depression (P < 0.001), fear of movement (P < 0.01), and pain catastrophizing (P < 0.001) from pre- to postintervention. Results of the readiness to change measure indicated a significant decrease in precontemplation (P < 0.01) and increase in action/maintenance scores (P < 0.001). All results demonstrated medium to large effect sizes.

CONCLUSION

Adolescents with juvenile FM reported significant improvements in physical function and reduced fear of movement following the intervention. Improvement in physical function was achieved in a shorter time frame than in a prior trial of CBT without an exercise component. Further work is needed to compare the FIT Teens program with existing approaches and determine whether objective changes in exercise participation are achieved.

The role of long-term physical exercise on performance and brain activation during the Stroop colour word task in fibromyalgia patients

The Stroop colour word test (SCWT) has been widely used to assess changes in cognitive performance such as processing speed, selective attention and the degree of automaticity. Moreover, the SCWT has proven to be a valuable tool to assess neuronal plasticity that is coupled to improvement in performance in clinical populations. In a previous study, we showed impaired cognitive processing during SCWT along with reduced task-related activations in patients with fibromyalgia. In this study, we used SCWT and functional magnetic resonance imagingFMRI to investigate the effects of a 15-week physical exercise intervention on cognitive performance, task-related cortical activation and distraction-induced analgesia (DIA) in patients with fibromyalgia and healthy controls. The exercise intervention yielded reduced fibromyalgia symptoms, improved cognitive processing and increased task-related activation of amygdala, but no effect on DIA. Our results suggest beneficial effects of physical exercise on cognitive functioning in FM.

Influence of stress systems and physical activity on different dimensions of fatigue in female fibromyalgia patients

OBJECTIVE

Fatigue is a defining characteristic and one of the most debilitating features of fibromyalgia syndrome (FMS). The mechanisms underlying different dimensions of fatigue in FMS remain unclear. The aim of the current study was to test whether stress-related biological processes and physical activity modulate fatigue experience.

METHODS

Using an ambulatory assessment design, 26 female FMS patients reported general, mental, and physical fatigue levels at six time points per day for 14 consecutive days. Salivary cortisol and alpha-amylase were analyzed as markers of neuroendocrine functioning. Participants wore wrist actigraphs for the assessment of physical activity.

RESULTS

Lower increases in cortisol after awakening predicted higher mean daily general and physical fatigue levels. Additionally, mean daily physical activity positively predicted next-day mean general fatigue. Levels of physical fatigue at a specific time point were positively associated with momentary cortisol levels. The increase in cortisol after awakening did not mediate the physical activity - fatigue relationship. There were no associations between alpha-amylase and fatigue.

CONCLUSION

Our findings imply that both changes in hypothalamic-pituitary-adrenal axis activity and physical activity contribute to variance in fatigue in the daily lives of patients with FMS. This study helps to paint a clearer picture of the biological and behavioral underpinnings of fatigue in FMS and highlight the necessity of interdisciplinary treatment approaches targeting biological, behavioral and psychological aspects of FMS.

The discordance between subjectively and objectively measured physical function in women with fibromyalgia: association with catastrophizing and self-efficacy cognitions. The al-Ándalus project

PURPOSE

People with fibromyalgia experience a disagreement between patient-reported (i.e., subjective) and performance-based (i.e., objective) status. This study aimed to (i) corroborate the discordance between subjectively and objectively measured physical function and (ii) examine whether catastrophizing (worrying, pain magnifying, and helpless cognitions) and self-efficacy (believing capable to manage pain) are independently associated with this discordance.

METHODS

This population-based cross-sectional study included 405 women with fibromyalgia and 193 age-matched female controls. Participants completed the Pain Catastrophizing Scale, Chronic Pain Self-efficacy Scale, and physical functioning subscales of the Revised Fibromyalgia Impact Questionnaire and Short Form-36 (SF-36) health survey. Objective physical function was measured with the Senior Fitness Test battery. Subjective and objective physical functions were expressed as deviation from the general population in standard deviation (SD) units using means and SD of the control group.

RESULTS

In fibromyalgia, subjective physical function was worse than objective physical function (p < 0.001). Higher catastrophizing was consistently associated with greater discordance between subjective and objective physical function, while self-efficacy was only significantly associated with this discordance when subjective physical function was assessed by means of the SF-36.

CONCLUSIONS

Subjective physical function is more impaired than objective physical function in fibromyalgia, yet both are markedly impaired. Catastrophizing cognitions are associated with this discordance. In particular, high catastrophizing may promote a feeling of reduced ability to do meaningful activities of daily living (i.e., restrictions) that people with fibromyalgia are actually able to. Therefore, catastrophizing should be assessed and potentially targeted when focusing on improving physical function in fibromyalgia. Implications for rehabilitation Rehabilitation should focus on physical exercise programs to help women with fibromyalgia to improve their reduced physical function. In rehabilitation settings, physical function of people with fibromyalgia should be evaluated by both subjective and objective assessments to fully understand physical functioning and to test the existence of discordance between both assessments. In case of a large discordance between subjective and objective physical function, a physical exercise program might be better complemented with cognitive management techniques to reduce catastrophizing and subjective physical dysfunction. When people with fibromyalgia experience high levels of catastrophizing, subjective assessments seem to be poor indicators of physical function.