A longitudinal, integrated, clinical, histological and mRNA profiling study of resistance exercise in myositis

Sarcopenia assessed by DXA and hand-grip dynamometer: a potential marker of damage, disability and myokines imbalance in inflammatory myopathies

OBJECTIVES

To assess the ability of dual-energy X-ray absorptiometry (DXA) and hand-grip dynamometer to measure damage in inflammatory myopathies (IM).

METHODS

Forty adult IM patients with a disease duration ≥12 months, low or no disease activity for ≥6 months, were prospectively enrolled. Thirty healthy age and sex-matched volunteers were enrolled as controls. Whole-body DXA and hand-grip dynamometer were used to measure muscle mass, grip strength and diagnose sarcopenia (EWGSOP2 criteria). Relationships between the results of strength in 12 muscles, functional tests, patient-reported disability, IMACS damage score, and history of the disease were assessed. The serum levels of potential molecular actors in the damage were measured.

RESULTS

DXA and grip strength measurements took ≤20 min. Both muscle mass and grip strength were decreased in IM patients vs volunteers (-10% and -30%, respectively) with a dispersion that varied widely (interquartile range -24.3% to +7.8% and -51.3% to -18.9%, respectively). Muscle mass and grip strength were non-redundantly correlated (r up to 0.6, P = 0.0001) with strength in 14 muscles (manual muscle test and hand-held dynamometer), functions (of limbs, respiratory and deglutition muscles), patient-reported disability, damage (extension and severity in muscular and extra-muscular domains) and blood levels of several myokines. Seven IM patients (17.5%) were sarcopenic. They had the worst damage, impaired functions, disability and history of severe myopathy. Decreased irisin and osteonectin levels were associated with sarcopenia (area under the curve 0.71 and 0.80, respectively).

CONCLUSION

DXA and hand-grip dynamometer are useful tools to assess damage in IM. Irisin and osteonectin may play a role in IM damage pathogenesis.

Saturation effects of the relationship between physical exercise and systemic immune inflammation index in the short-sleep population: a cross-sectional study

BACKGROUND

Short sleep can lead to an increase in inflammation and regular exercise has been shown to have a mitigation effect. However, the association between physical exercise (PE) and inflammation in the short sleep population is an unknown and intriguing issue.

METHODS

NHANES dataset spanning the years 2007 to 2018 were analyzed. To investigate the relationship mentioned above, we carried out multivariate linear regression models controlling for sociodemographic and lifestyles factors. The systemic immune inflammation index (SII) served as a reflection of inflammatory potential, calculated as the product of platelet count, neutrophil count, and divided by the lymphocyte count. Self-reported questionnaires were used to collect sleep and exercise information.

RESULTS

A total of 14,664 participants were included for final analysis. Across the three models, PE showed significant negative associations with SII as a continuous variable [Crude Model, β (95% CI): -1.261(-1.600, -0.922), p < 0.001; Model 1, β (95% CI): -1.005(-1.344, -0.666), p < 0.001; Model 2, β (95% CI): -0.470(-0.827, -0.112), p = 0.011]. The consistent nature of the findings persisted when investigating physical exercise (PE) as a categorized variable. By two-piecewise linear regression model, we calculated a saturation effect of PE with the inflection point as 2400 MET-minutes/week.

CONCLUSION

This study suggested that performing no more than 2400 MET-minutes/week of PE was associated with lower SII levels in the short sleep population, while more PE might not bring additional benefits.

The Role of Exercise to Improve Physiological, Physical and Psychological Health Outcome in Idiopathic Inflammatory Myopathies (IIM)

Idiopathic inflammatory myopathies (IIM) impact all aspects of health, physiological, physical, and psychological. Hallmark symptoms of IIM are muscle weakness, reduced muscle endurance and aerobic capacity. Recently, pain and fatigue as well as anxiety and depression have emerged as common and debilitating symptoms in patients with IIM. The aim of this scoping review is to, in a holistic way, describe how IIM impact patients' physiological, physical, and psychological health and how exercise has a role to treat as well as potentially counteract the effects of the disease. Inflammation induces non-immune response and organ damage. These changes with additional impact of physical inactivity lead to muscle impairment and reduced aerobic capacity. Pain, fatigue and low psychological well-being and overall quality of life are also common health aspects of IIM. Medical treatment can reduce inflammation but has in turn serious side effects such as muscle atrophy, type-II diabetes, and hypertension, which exercise has the potential to treat, and perhaps also counteract. In addition, exercise improves muscle function, aerobic capacity and might also reduce fatigue and pain. New evidence shows that reducing systemic inflammation may also improve patient-reported subjective health, quality of life and psychological well-being. Exercise in combination with medical treatment is becoming an important part of the treatment for patients with IIM as exercise has the potential to promote health aspects of various dimensions in patients with IIM.

The molecular mechanism underlying dermatomyositis related interstitial lung disease: evidence from bioinformatic analysis and in vivo validation

Background

Dermatomyositis (DM) is an autoimmune and inflammatory disease that can affect the lungs, causing interstitial lung diseases (ILD). However, the exact pathophysiological mechanisms underlying DM-ILD are unknown. Idiopathic pulmonary fibrosis (IPF) belongs to the broader spectrum of ILD and evidence shows that common pathologic pathways might lie between IPF and DM-ILD.

Methods

We retrieved gene expression profiles of DM and IPF from the Gene Expression Omnibus (GEO) and utilized weighted gene co-expression network analysis (WGCNA) to reveal their co-expression modules. We then performed a differentially expressed gene (DEG) analysis to identify common DEGs. Enrichment analyses were employed to uncover the hidden biological pathways. Additionally, we conducted protein-protein interaction (PPI) networks analysis, cluster analysis, and successfully found the hub genes, whose levels were further validated in DM-ILD patients. We also examined the relationship between hub genes and immune cell abundance in DM and IPF. Finally, we conducted a common transcription factors (TFs)-genes network by NetworkAnalyst.

Results

WGCNA revealed 258 intersecting genes, while DEG analysis identified 66 shared genes in DM and IPF. All of these genes were closely related to extracellular matrix and structure, cell-substrate adhesion, and collagen metabolism. Four hub genes (POSTN, THBS2, COL6A1, and LOXL1) were derived through intersecting the top 30 genes of the WGCNA and DEG sets. They were validated as active transcripts and showed diagnostic values for DM and IPF. However, ssGSEA revealed distinct infiltration patterns in DM and IPF. These four genes all showed a positive correlation with immune cells abundance in DM, but not in IPF. Finally, we identified one possible key transcription factor, MYC, that interact with all four hub genes.

Conclusion

Through bioinformatics analysis, we identified common hub genes and shared molecular pathways underlying DM and IPF, which provides valuable insights into the intricate mechanisms of these diseases and offers potential targets for diagnostic and therapeutic interventions.

Effects of acute moderate-intensity aerobic exercise on cognitive function in E-athletes: A randomized controlled trial

BACKGROUND

E-sports require athletes to have high-speed reflexes and excellent memory skills. Whereas a single session of aerobic exercise has been shown to improve cognitive function, this paper aims is to investigate the effects of acute moderate-intensity aerobic exercise on the cognitive function of e-sports players and its time-course characteristics.

METHODS

Thirty-four E-athletes were divided into 2 groups according to a random number table method, and 2 trials in a quiet physical fitness gym. The duration of each trial was approximately 1 hour. In the first trial: exercise group (64-76% of maximum heart rate for 30 minutes power cycling) and control group, cognitive function was tested, and results were automatically recorded before, immediately after, and 30 minutes after exercise using the human benchmark website (https://humanbenchmark.com). The second trial crossed and swapped the interventions of the 2 groups, and the other test protocols were the same as the first.

RESULTS

In both trials, the exercise intervention group showed significant improvements in speed accuracy (P < .001, Cohen's d = 1.406, 95% CI: 0.717-2.072; P = .005, Cohen's d = 0.782, 95% CI: 0.227-1.319), visual memory (P < .001, Cohen's d = 1.416, 95% CI: 0.725-2.086; P = .015, Cohen's d = 0.662, 95% CI: 0.127-1.181), and reaction time (P < .001, Cohen's d = 1.265, 95% CI: 0.610-1.898; P<.001, Cohen's d = 0.979, 95% CI: 0.386-1.551) immediately after exercise compared to baseline. The exercise intervention group also showed significant improvement in speed accuracy 30 minutes after exercise compared to baseline (P = .002 Cohen's d = 0.869, 95% CI: 0.298-1.421; P = .009, Cohen's d = 0.722, 95% CI: 0.177-1.249). In the first trial, the exercise intervention group showed significant improvements in visual memory and reaction time immediately after exercise compared to the control group (P = .013, Cohen's d = 0.904, 95% CI: 0.190-1.605; P = .027, Cohen's d = 0.796, 95% CI: 0.090-1.490). The exercise intervention group also showed significant improvement in reaction time 30 minutes after exercise compared to baseline (P = .009, Cohen's d = 0.719, 95% CI: 0.174-1.246). There was no effect of exercise on sequence memory or the chimp test in both trials (P > .05). Sequence effect analysis showed no influence on the order of the exercise intervention in both trials (P = .912; P = .111; P = .226).

CONCLUSION

Acute moderate-intensity aerobic exercise significantly enhanced the speed accuracy, visual reaction time, and instantaneous memory of eSports players, and the effect could be extended up to 30 minutes after exercise.

Urine proteomics by mass spectrometry identifies proteins involved in key pathogenic pathways in patients with juvenile dermatomyositis

OBJECTIVES

To identify and validate biomarkers in JDM patients using a multiplexing tandem mass tag urine proteome profiling approach.

METHODS

First morning void urine samples were collected from JDM patients (n = 20) and healthy control subjects (n = 21) and processed for analysis using a standardized liquid chromatography-tandem mass spectrometry approach. Biomarkers with significantly altered levels were correlated with clinical measures of myositis disease activity and damage. A subset of candidate biomarkers was validated using commercially available ELISA kits.

RESULTS

In total, 2348 proteins were detected in the samples, with 275 proteins quantified across all samples. Among the differentially altered proteins, cathepsin D and galectin-3 binding protein were significantly increased in the urine of JDM patients (adjusted P < 0.05), supporting previous findings in myositis patients. These two candidate biomarkers were confirmed with ELISAs. Cathepsin D positively correlated with Myositis Damage Index (r = 0.57, P < 0.05) and negatively correlated with the Childhood Myositis Assessment Scale (r = -0.54, P < 0.05). We also identified novel JDM candidate biomarkers involved with key features of myositis, including extracellular matrix remodelling proteins.

CONCLUSION

This study confirmed the presence of several proteins in the urine of JDM patients that were previously found to be elevated in the blood of myositis patients and identified novel candidate biomarkers that require validation. These results support the use of urine as a source for biomarker development in JDM.

Harnessing the benefits of yoga for myositis, muscle dystrophies, and other musculoskeletal disorders

The recent global increase in popularity of home-based yoga, an ancient Indian technique practiced for thousands of years, has translated into its use as a complementary therapy for a multitude of ailments. This review aims to examine the published literature regarding the effects of yoga therapy on systemic chronic diseases; in particular on the inflammatory myopathies (IMs) and other muscle disorders.

Despite the fact that the evidence base for yoga in inflammatory myositis is in its infancy, collateral results in other disorders such as muscular dystrophies are promising. A beneficial effect of yoga in chronic pain has been shown alongside an improvement in motor function and muscle strength. Patients with Duchenne muscular dystrophy with respiratory involvement may find improvement in lung function. Elderly patients may experience reduction in falls secondary to an improvement in balance while practicing long-term yoga therapy.

Further benefits are improving disorders of mental health such as depression and anxiety. A reported improvement in overall quality of life further suggests its efficacy in reducing morbidity in patients with chronic diseases, who often suffer co-existent psychological comorbidities.

Improved skeletal muscle fatigue resistance in experimental autoimmune myositis mice following high-intensity interval training

Background

Muscle weakness and decreased fatigue resistance are key manifestations of systemic autoimmune myopathies (SAMs). We here examined whether high-intensity interval training (HIIT) improves fatigue resistance in the skeletal muscle of experimental autoimmune myositis (EAM) mice, a widely used animal model for SAM.

Methods

Female BALB/c mice were randomly assigned to control (CNT) or EAM groups (n = 28 in each group). EAM was induced by immunization with three injections of myosin emulsified in complete Freund’s adjuvant. The plantar flexor (PF) muscles of mice with EAM were exposed to either an acute bout or 4 weeks of HIIT (a total of 14 sessions).

Results

The fatigue resistance of PF muscles was lower in the EAM than in the CNT group (P < 0.05). These changes were associated with decreased activities of citrate synthase and cytochrome c oxidase and increased expression levels of the endoplasmic reticulum stress proteins (glucose-regulated protein 78 and 94, and PKR-like ER kinase) (P < 0.05). HIIT restored all these alterations and increased the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and the mitochondrial electron transport chain complexes (I, III, and IV) in the muscles of EAM mice (P < 0.05).

Conclusions

HIIT improves fatigue resistance in a SAM mouse model, and this can be explained by the restoration of mitochondria oxidative capacity via inhibition of the ER stress pathway and PGC-1α-mediated mitochondrial biogenesis.

Cardiovascular Health in Pediatric Rheumatologic Diseases

Cardiovascular disease risk is evident during childhood for patients with juvenile systemic lupus erythematosus, juvenile dermatomyositis, and juvenile idiopathic arthritis. The American Heart Association defines cardiovascular health as a positive health construct reflecting the sum of protective factors against cardiovascular disease. Disease-related factors such as chronic inflammation and endothelial dysfunction increase cardiovascular disease risk directly and through bidirectional relationships with poor cardiovascular health factors. Pharmacologic and nonpharmacologic interventions to improve cardiovascular health and long-term cardiovascular outcomes in children with rheumatic disease are needed.

The effects of resistance training in patients with primary Sjogren's syndrome

INTRODUCTION

Resistance training (RT) is well tolerated and has shown promise for decreasing fatigue. However, the effects of RT have never been examined in primary Sjogren's syndrome (pSS).

OBJECTIVE

To assess the feasibility, effectiveness, and safety of a resistance exercise program on fatigue in patients with pSS.

METHODS

This is a parallel, single-blind randomized trial. Women aged 18 years or older, diagnosed with pSS according to the American-European criteria, were included. We randomized 59 participants to a resistance training group (RT) or a control group (CG). Participants in the RT group performed a 16-week resistance exercise program. The sessions consisted of three sets of resistance exercises (10 repetitions each) at 60 to 80% of 1 repetition maximum, designed to improve whole-body strength. The participants in the CG received their usual pharmacological treatment and instructions regarding disease control, pain management, sleep hygiene, and activities of daily living. To compare intergroup and intragroup variability, a one-factor repeated-measures analysis of variance (ANOVA) was used.

RESULTS

RT effectively improved fatigue, pain, functional capacity, emotional aspects, vitality, and subjective perception of disease activity by the patient. No between-group differences were found in the ESSPRI mental score, ESSDAI, SF-36-Physical Aspects, SF-36-General Health, SF-36-Social aspects, and SF-36-Mental Health after the training period.

CONCLUSION

An RT program was safe and effective in improving fatigue, pain, functional capacity, emotional aspects, vitality, and subjective perception of disease activity by the patient in women with pSS. Key Points • This is the first study to evaluate the effects of a resistance training program on fatigue in patients with primary Sjogren's syndrome. • A resistance training program was shown to be effective in improving fatigue in patients with primary Sjogren's syndrome. • A resistance training program is well-tolerated, has good compliance, and is not associated with serious adverse effects in patients with primary Sjogren's syndrome.

High-intensity strength training in patients with idiopathic inflammatory myopathies: a randomised controlled trial protocol

INTRODUCTION

Idiopathic inflammatory myopathies (IIMs) are rare diseases characterised by non-suppurative inflammation of skeletal muscles and muscle weakness. Additionally, IIM is associated with a reduced quality of life. Strength training is known to promote muscle hypertrophy and increase muscle strength and physical performance in healthy young and old adults. In contrast, only a few studies have examined the effects of high intensity strength training in patients with IIM and none using a randomised controlled trial (RCT) set-up. Thus, the purpose of this study is to investigate the effects of high-intensity strength training in patients affected by the IIM subsets polymyositis (PM), dermatomyositis (DM) and immune-mediated necrotising myopathy (IMNM) using an RCT study design.

METHODS AND ANALYSIS

60 patients with PM, DM or IMNM will be included and randomised into (1) high-intensity strength training or (2) Care-as-Usual. The intervention period is 16 weeks comprising two whole-body strength exercise sessions per week. The primary outcome parameter will be the changes from pre training to post training in the Physical Component Summary measure in the Short Form-36 health questionnaire. Secondary outcome measures will include maximal lower limb muscle strength, skeletal muscle mass, functional capacity, disease status (International Myositis Assessment and Clinical Studies Group core set measures) and questionnaires assessing physical activity levels and cardiovascular comorbidities. Furthermore, blood samples and muscle biopsies will be collected for subsequent analyses.

ETHICS AND DISSEMINATION

The study complies with the Helsinki Declaration II and is approved by The Danish Data Protection Agency (P-2020-553). The study is approved by The Danish National Committee on Health Research Ethics (H-20030409). The findings of this trial will be submitted to relevant peer-reviewed journals. Abstracts will be submitted to international conferences.

TRIAL REGISTRATION NUMBER

NCT04486261.

The pathophysiological effects of exercise in the management of idiopathic inflammatory myopathies: A scoping review

Idiopathic inflammatory myopathy (IIM) is a term used for a heterogeneous group of diseases characterized by severe muscle weakness. In addition to pharmacological treatment options, non-pharmacological methods such as exercising are essential for proper management of myositis. The present article aimed to provide an insight into the potential pathophysiological mechanisms underlying exercise-related benefits in myositis. A systematic search was performed on PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar using the following keywords and their combinations: "idiopathic inflammatory myopathy", "inflammatory myopathy", "myositis", "polymyositis", "dermatomyositis", "inclusion body myositis", and "exercise". Current literature indicates that exercising has impact on both immune and non-immune pathways in patients with IIM. Exercise-related benefits include (a) increased mitochondrial biogenesis/enzyme activity, (b) reconditioning of immune/inflammatory pathways, (c) decreased endoplasmic reticulum stress, (d) modulation of gene expression, (e) increased protein synthesis and cytoskeletal remodeling, and (f) decreased muscle fibrosis and non-muscle area infiltrates. With its certain benefits, exercise stands as a precious non-pharmacological treatment option for patients with IIM.

Efetividade do treinamento físico sobre o desempenho físico em pacientes com dermatomiosite e polimiosite: revisão sistemática e metanálise

RESUMO Este estudo teve por objetivo avaliar o impacto do treinamento físico sobre o desempenho físico em pacientes com dermatomiosite e polimiosite. Para tanto, uma revisão sistemática e metanálise foi conduzida de acordo com as diretrizes do PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). A pesquisa bibliográfica foi realizada nas seguintes bases de dados: PubMed/MEDLINE e Web of Science, utilizando combinações das seguintes palavras-chave em inglês: dermatomyositis OR polymyositis OR myositis AND exercise OR physical exercise OR physical therapy OR aerobic exercise OR endurance exercise OR resistance exercise. Foram incluídos estudos que atenderam aos seguintes critérios: (1) os participantes apresentavam diagnóstico de dermatomiosite ou polimiosite; (2) os pacientes foram submetidos a um protocolo de treinamento físico; (3) o desempenho físico foi mensurado antes e após o protocolo de treinamento físico. Um total de 14 artigos foram selecionados para inclusão na revisão sistemática e 10 artigos foram selecionados para inclusão na metanálise. Os resultados demonstram que o treinamento físico é eficaz em aumentar o desempenho físico global nos pacientes com dermatomiosite e polimiosite (tamanho do efeito: 0,72; IC 95% 0,55; 0,89). Além disso, foi demonstrado também que tanto as variáveis de desempenho aeróbio (tamanho do efeito: 0,88; IC 95% 0,54; 1,21), quanto as variáveis de desempenho resistido (tamanho do efeito: 0,64; IC 95% 0,43; 0,85) são beneficiadas com o treinamento físico nesses pacientes. Conclui-se que o treinamento físico apresentou um efeito benéfico significativo sobre o desempenho físico global, aeróbio e resistido em pacientes com dermatomiosite e polimiosite.

Eccentric Resistance Training Ameliorates Muscle Weakness in a Mouse Model of Idiopathic Inflammatory Myopathies

OBJECTIVE

High-force eccentric contractions (ECCs) have traditionally been excluded from rehabilitation programs that include patients with idiopathic inflammatory myopathies (IIMs) due to unverified fear of causing muscle damage and inflammation. In an IIM animal model that used mice with experimental autoimmune myositis (EAM), we undertook this study to investigate whether ECC training can safely and effectively be used to counteract muscle weakness in IIM.

METHODS

EAM was induced in BALB/c mice by immunization with 3 injections of myosin emulsified in Freund's complete adjuvant. Controls (n = 12) and mice with EAM (n = 12) were exposed to either an acute bout of 100 ECCs or 4 weeks of ECC training (20 ECCs every other day). To induce ECCs, plantar flexor muscles were electrically stimulated while the ankle was forcibly dorsiflexed.

RESULTS

Less cell damage, as assessed by Evans blue dye uptake, was observed in the muscles of mice with EAM, compared to controls, after an acute bout of 100 ECCs (P < 0.05). Maximum Ca²⁺ -activated force was decreased in skinned gastrocnemius muscle fibers from mice with EAM, and this was accompanied by increased expression of endoplasmic reticulum (ER) stress proteins, including Gsp78 and Gsp94 (P < 0.05). ECC training prevented the decrease in force and the increase in ER stress proteins and also enhanced the expression and myofibrillar binding of small heat-shock proteins (HSPs) (P < 0.05), which can stabilize myofibrillar structure and function.

CONCLUSION

ECC training protected against the reduction in myofibrillar force-generating capacity in an IIM mouse model, and this occurred via inhibition of ER stress responses and small HSP-mediated myofibrillar stabilization.

The altered metabolism profile in pathogenesis of idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases characterized by muscle weakness, muscle inflammation and extramuscular manifestations. Despite extensive efforts, the mechanisms of IIMs remain largely unknown, and treatment is still a challenge for physicians. Metabolism changes have emerged as a crucial player in autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). However, little is known about metabolism changes in IIMs. In this review, we focus on the alteration of metabolism profile in IIMs, and the relationships with clinical information. We highlight the potential roles of metabolism in the pathogenesis of IIMs and discuss future perspectives for metabolic checkpoint-based therapeutic interventions.

The immune system in sporadic inclusion body myositis patients is not compromised by blood-flow restricted exercise training

BACKGROUND

Sporadic inclusion body myositis (sIBM) is clinically characterised by progressive proximal and distal muscle weakness and impaired physical function while skeletal muscle tissue displays abnormal cellular infiltration of T cells, macrophages, and dendritic cells. Only limited knowledge exists about the effects of low-load blood flow restriction exercise in sIBM patients, and its effect on the immunological responses at the myocellular level remains unknown. The present study is the first to investigate the longitudinal effects of low-load blood flow restriction exercise on innate and adaptive immune markers in skeletal muscle from sIBM patients.

METHODS

Twenty-two biopsy-validated sIBM patients were randomised into either 12 weeks of low-load blood flow restriction exercise (BFRE) or no exercise (CON). Five patients from the control group completed 12 weeks of BFRE immediately following participation in the 12-week control period leading to an intervention group of 16 patients. Muscle biopsies were obtained from either the m. tibialis anterior or the m. vastus lateralis for evaluation of CD3-, CD8-, CD68-, CD206-, CD244- and FOXP3-positive cells by three-colour immunofluorescence microscopy and Visiopharm-based image analysis quantification. A linear mixed model was used for the statistical analysis.

RESULTS

Myocellular infiltration of CD3^-/CD8⁺ expressing natural killer cells increased following BFRE (P < 0.05) with no changes in CON. No changes were observed for CD3⁺/CD8^- or CD3⁺/CD8⁺ T cells in BFRE or CON. CD3⁺/CD244⁺ T cells decreased in CON, while no changes were observed in BFRE. Pronounced infiltration of M1 pro-inflammatory (CD68⁺/CD206^-) and M2 anti-inflammatory (CD68⁺/CD206⁺) macrophages were observed at baseline; however, no longitudinal changes in macrophage content were observed for both groups.

CONCLUSIONS

Low-load blood flow restriction exercise elicited an upregulation in CD3^-/CD8⁺ expressing natural killer cell content, which suggests that 12 weeks of BFRE training evokes an amplified immune response in sIBM muscle. However, the observation of no changes in macrophage or T cell infiltration in the BFRE-trained patients indicates that patients with sIBM may engage in this type of exercise with no risk of intensified inflammatory activity.

Strength training and aerobic exercise training for muscle disease

BACKGROUND

Strength training or aerobic exercise programmes, or both, might optimise muscle and cardiorespiratory function and prevent additional disuse atrophy and deconditioning in people with a muscle disease. This is an update of a review first published in 2004 and last updated in 2013. We undertook an update to incorporate new evidence in this active area of research.

OBJECTIVES

To assess the effects (benefits and harms) of strength training and aerobic exercise training in people with a muscle disease.

SEARCH METHODS

We searched Cochrane Neuromuscular's Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL in November 2018 and clinical trials registries in December 2018.

SELECTION CRITERIA

Randomised controlled trials (RCTs), quasi-RCTs or cross-over RCTs comparing strength or aerobic exercise training, or both lasting at least six weeks, to no training in people with a well-described muscle disease diagnosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 14 trials of aerobic exercise, strength training, or both, with an exercise duration of eight to 52 weeks, which included 428 participants with facioscapulohumeral muscular dystrophy (FSHD), dermatomyositis, polymyositis, mitochondrial myopathy, Duchenne muscular dystrophy (DMD), or myotonic dystrophy. Risk of bias was variable, as blinding of participants was not possible, some trials did not blind outcome assessors, and some did not use an intention-to-treat analysis. Strength training compared to no training (3 trials) For participants with FSHD (35 participants), there was low-certainty evidence of little or no effect on dynamic strength of elbow flexors (MD 1.2 kgF, 95% CI -0.2 to 2.6), on isometric strength of elbow flexors (MD 0.5 kgF, 95% CI -0.7 to 1.8), and ankle dorsiflexors (MD 0.4 kgF, 95% CI -2.4 to 3.2), and on dynamic strength of ankle dorsiflexors (MD -0.4 kgF, 95% CI -2.3 to 1.4). For participants with myotonic dystrophy type 1 (35 participants), there was very low-certainty evidence of a slight improvement in isometric wrist extensor strength (MD 8.0 N, 95% CI 0.7 to 15.3) and of little or no effect on hand grip force (MD 6.0 N, 95% CI -6.7 to 18.7), pinch grip force (MD 1.0 N, 95% CI -3.3 to 5.3) and isometric wrist flexor force (MD 7.0 N, 95% CI -3.4 to 17.4). Aerobic exercise training compared to no training (5 trials) For participants with DMD there was very low-certainty evidence regarding the number of leg revolutions (MD 14.0, 95% CI -89.0 to 117.0; 23 participants) or arm revolutions (MD 34.8, 95% CI -68.2 to 137.8; 23 participants), during an assisted six-minute cycle test, and very low-certainty evidence regarding muscle strength (MD 1.7, 95% CI -1.9 to 5.3; 15 participants). For participants with FSHD, there was low-certainty evidence of improvement in aerobic capacity (MD 1.1 L/min, 95% CI 0.4 to 1.8, 38 participants) and of little or no effect on knee extension strength (MD 0.1 kg, 95% CI -0.7 to 0.9, 52 participants). For participants with dermatomyositis and polymyositis (14 participants), there was very low-certainty evidence regarding aerobic capacity (MD 14.6, 95% CI -1.0 to 30.2). Combined aerobic exercise and strength training compared to no training (6 trials) For participants with juvenile dermatomyositis (26 participants) there was low-certainty evidence of an improvement in knee extensor strength on the right (MD 36.0 N, 95% CI 25.0 to 47.1) and left (MD 17 N 95% CI 0.5 to 33.5), but low-certainty evidence of little or no effect on maximum force of hip flexors on the right (MD -9.0 N, 95% CI -22.4 to 4.4) or left (MD 6.0 N, 95% CI -6.6 to 18.6). This trial also provided low-certainty evidence of a slight decrease of aerobic capacity (MD -1.2 min, 95% CI -1.6 to 0.9). For participants with dermatomyositis and polymyositis (21 participants), we found very low-certainty evidence for slight increases in muscle strength as measured by dynamic strength of knee extensors on the right (MD 2.5 kg, 95% CI 1.8 to 3.3) and on the left (MD 2.7 kg, 95% CI 2.0 to 3.4) and no clear effect in isometric muscle strength of eight different muscles (MD 1.0, 95% CI -1.1 to 3.1). There was very low-certainty evidence that there may be an increase in aerobic capacity, as measured with time to exhaustion in an incremental cycle test (17.5 min, 95% CI 8.0 to 27.0) and power performed at VO2 max (maximal oxygen uptake) (18 W, 95% CI 15.0 to 21.0). For participants with mitochondrial myopathy (18 participants), we found very low-certainty evidence regarding shoulder muscle (MD -5.0 kg, 95% CI -14.7 to 4.7), pectoralis major muscle (MD 6.4 kg, 95% CI -2.9 to 15.7), and anterior arm muscle strength (MD 7.3 kg, 95% CI -2.9 to 17.5). We found very low-certainty evidence regarding aerobic capacity, as measured with mean time cycled (MD 23.7 min, 95% CI 2.6 to 44.8) and mean distance cycled until exhaustion (MD 9.7 km, 95% CI 1.5 to 17.9). One trial in myotonic dystrophy type 1 (35 participants) did not provide data on muscle strength or aerobic capacity following combined training. In this trial, muscle strength deteriorated in one person and one person had worse daytime sleepiness (very low-certainty evidence). For participants with FSHD (16 participants), we found very low-certainty evidence regarding muscle strength, aerobic capacity and VO2 peak; the results were very imprecise. Most trials reported no adverse events other than muscle soreness or joint complaints (low- to very low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence regarding strength training and aerobic exercise interventions remains uncertain. Evidence suggests that strength training alone may have little or no effect, and that aerobic exercise training alone may lead to a possible improvement in aerobic capacity, but only for participants with FSHD. For combined aerobic exercise and strength training, there may be slight increases in muscle strength and aerobic capacity for people with dermatomyositis and polymyositis, and a slight decrease in aerobic capacity and increase in muscle strength for people with juvenile dermatomyositis. More research with robust methodology and greater numbers of participants is still required.

Physical therapy in adult inflammatory myopathy patients: a systematic review

The safety and effect of physical therapy in adult patients with idiopathic inflammatory myopathies (IIMs) are currently unclear. Considering the muscle weakness resulting from disease activity as well as from the administered drugs, these patients could benefit from an evidence-based physical therapy program. To perform a systematic review to assess safety and effects of physical therapy on the functional outcome of patients with idiopathic inflammatory myopathies in both active and quiescent disease: Pubmed, Embase, and Cochrane. Patients with one of the following idiopathic inflammatory myopathies: polymyositis, dermatomyositis, immune-mediated necrotizing myopathy, and/or overlap myositis. The intervention included several types of rehabilitation programs, from strength and resistance training to endurance training, with a minimal duration of 1 month. Studies reporting intervention-related adverse events, disease activity, and functional outcomes were eligible. The risk of bias was assessed using the Cochrane guidelines. We included five randomized controlled and seven open-label non-randomized non-controlled trials. Data on statistical significance were extracted for all the trials. Included trials were of medium-quality evidence given the low number of patients and some risk of bias factors. Physical therapy does not have a negative effect on the disease activity of idiopathic inflammatory myopathies in quiescent disease and could improve functional outcome. The physical therapy program should minimally include endurance training. A combination with resistance training might be beneficial.

Guidelines of the Brazilian Society of Rheumatology for the treatment of systemic autoimmune myopathies

BACKGROUND

Recommendations of the Myopathy Committee of the Brazilian Society of Rheumatology for the management and therapy of systemic autoimmune myopathies (SAM).

MAIN BODY

The review of the literature was done in the search for the Medline (PubMed), Embase and Cochrane databases including studies published until June 2018. The Prisma was used for the systematic review and the articles were evaluated according to the levels of Oxford evidence. Ten recommendations were developed addressing the management and therapy of systemic autoimmune myopathies.

CONCLUSIONS

Robust data to guide the therapeutic process are scarce. Although not proven effective in controlled clinical trials, glucocorticoid represents first-line drugs in the treatment of SAM. Intravenous immunoglobulin is considered in induction for refractory cases of SAM or when immunosuppressive drugs are contra-indicated. Consideration should be given to the early introduction of immunosuppressive drugs. There is no specific period determined for the suspension of glucocorticoid and immunosuppressive drugs when individually evaluating patients with SAM. A key component for treatment in an early rehabilitation program is the inclusion of strength-building and aerobic exercises, in addition to a rigorous evaluation of these activities for remission of disease and the education of the patient and his/her caregivers.

Exercise in Myositis

Purpose of the review

A growing body of evidence supports exercise as a very important part of the treatment for adult patients with idiopathic inflammatory myopathies (IIM). This review mainly focuses on exercise studies published during the last 2 years in adult myositis.

Recent findings

During the last couple of years, new publications present further evidence for intensive endurance exercise as an anti-inflammatory treatment inducing muscle growth and improving mitochondrial function compared a non-exercising control group. Further, blood-flow restricted resistance training was effective to maintain muscle strength compared to a non-exercising control group which lost a mean of 9.2% in quadriceps strength over 3 months in inclusion body myositis. Another study evaluates the effects of intra-muscular injections of an isoform of follistatin (FS344) by AAV1 in combination with exercise in a small group of patients with inclusion body myositis. An improvement in physical capacity was associated to higher exercise levels. Less is known about exercise effects in patients with recent onset, active polymyositis, and dermatomyositis.

Summary

All studies report safety of exercise in all types and stages of myositis and exercise could now be considered as medicine. It is recommended to initiate exercise on a low intensity under supervision of a physical therapist with regular follow-up and progression of intensity over time.

Advances in the early diagnosis and therapy of inclusion body myositis

PURPOSE OF REVIEW

To describe recent advancements in diagnostic and therapeutic approaches to inclusion body myositis (IBM).

RECENT FINDINGS

Our understanding of the implications of anti-cytosolic 5'-nucleotidase 1A autoantibody status in IBM and other diseases is increasing. Muscle imaging using magnetic resonance techniques and ultrasound is increasingly being performed and characteristic patterns of muscle involvement may help with diagnosis. Longitudinal imaging studies are likely to help with monitoring and as an outcome measure in clinical trials. Recent small-scale studies of Arimoclomol and Rapamycin have shown promising results and further investigation of these medications is ongoing. Exercise is likely to form an increasingly important facet of management of patients with IBM, but the optimal type of exercise programme to enrol patients in is not yet determined.

SUMMARY

Antibody testing and muscle imaging results may improve our ability to diagnose IBM and the availability of effective disease modifying treatments targeting novel non-inflammatory pathways could soon become a reality. It remains the duty of those involved in the management of patients with IBM to facilitate involvement in clinical trials and other research studies.

Physical exercise among patients with systemic autoimmune myopathies

Systemic autoimmune myopathies (SAMs) are a heterogeneous group of rare systemic autoimmune diseases that primarily affect skeletal muscles. Patients with SAMs show progressive skeletal muscle weakness and consequent functional disabilities, low health quality, and sedentary lifestyles. In this context, exercise training emerges as a non-pharmacological therapy to improve muscle strength and function as well as the clinical aspects of these diseases. Because many have feared that physical exercise exacerbates inflammation and consequently worsens the clinical manifestations of SAMs, it is necessary to evaluate the possible benefits and safety of exercise training among these patients. The present study systematically reviews the evidence associated with physical training among patients with SAMs.

Chronic inflammation in skeletal muscle impairs satellite cells function during regeneration: can physical exercise restore the satellite cell niche?

Chronic inflammation impairs skeletal muscle regeneration. Although many cells are involved in chronic inflammation, macrophages seem to play an important role in impaired muscle regeneration since these cells are associated with skeletal muscle stem cell (namely, satellite cells) activation and fibro-adipogenic progenitor cell (FAP) survival. Specifically, an imbalance of M1 and M2 macrophages seems to lead to impaired satellite cell activation, and these are the main cells that function during skeletal muscle regeneration, after muscle damage. Additionally, this imbalance leads to the accumulation of FAPs in skeletal muscle, with aberrant production of pro-fibrotic factors (e.g., extracellular matrix components), impairing the niche for proper satellite cell activation and differentiation. Treatments aiming to block the inflammatory pro-fibrotic response are partially effective due to their side effects. Therefore, strategies reverting chronic inflammation into a pro-regenerative pattern are required. In this review, we first describe skeletal muscle resident macrophage ontogeny and homeostasis, and explain how macrophages are replenished after muscle injury. We next discuss the potential role of chronic physical activity and exercise in restoring the M1 and M2 macrophage balance and consequently, the satellite cell niche to improve skeletal muscle regeneration after injury.

Effect of endurance exercise on microRNAs in myositis skeletal muscle-A randomized controlled study

OBJECTIVE

To identify changes in skeletal muscle microRNA expression after endurance exercise and associate the identified microRNAs with mRNA and protein expression to disease-specific pathways in polymyositis (PM) and dermatomyositis (DM) patients.

METHODS

Following a parallel clinical trial design, patients with probable PM or DM, exercising less than once a week, and on stable medication for at least one month were randomized into two groups at Karolinska University Hospital: a 12-week endurance exercise group (n = 12) or a non-exercised control group (n = 11). Using an Affymetrix microarray, microRNA expression was determined in paired muscle biopsies taken before and after the exercise intervention from 3 patients in each group. Ingenuity pathway analysis with a microRNA target filter was used to identify microRNA transcript targets. These targets were investigated at the mRNA (microarray) and protein (mass spectrometry) levels in patients.

RESULTS

Endurance exercise altered 39 microRNAs. The microRNAs with increased expression were predicted to target transcripts involved in inflammatory processes, metabolism, and muscle atrophy. Further, these target transcripts had an associated decrease in mRNA expression in exercised patients. In particular, a decrease in the NF-κB regulator IKBKB was associated with an increase in its target microRNA (miR-196b). At the protein level, there was an increase in mitochondrial proteins (AK3, HIBADH), which were associated with a decrease in microRNAs that were predicted to regulate their expression.

CONCLUSION

Improvement in disease phenotype after exercise is associated with increasing microRNAs that target and downregulate immune processes at the transcript level, as well as decreasing microRNAs that target and upregulate mitochondrial content at the protein level. Therefore, microRNAs may improve disease by decreasing immune responses and increasing mitochondrial biogenesis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01184625.

Postrehabilitation Functional Improvements in Patients With Inflammatory Myopathies: The Results of a Randomized Controlled Trial

OBJECTIVE

To evaluate the medium-term functional effect and the effect on quality of life of a standardized rehabilitation program in patients with inflammatory myopathies (IMs).

DESIGN

A multicenter, randomized controlled trial.

SETTING

Four university hospitals.

PARTICIPANTS

Patients (N=21) with polymyositis.

INTERVENTIONS

The intervention group participated in a 4-week standardized, hospital-based rehabilitation program followed by a personalized, self-managed, home-based rehabilitation program. The control group received physiotherapy on an outpatient basis. Study participants were evaluated at inclusion, at the end of the rehabilitation program (1mo), and then at 6 and 12 months.

MAIN OUTCOME MEASURES

The primary efficacy criterion was the Health Assessment Questionnaire Disability Index (HAQ-DI), and the secondary criteria were quality of life (according to the Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36] questionnaire), muscle performance (isokinetic strength, Motor Function Measure, and Kendall Manual Muscle Test), gait, pain, fatigue, and biomarkers of tolerance and disease activity.

RESULTS

At 12 months, the mean ± SD HAQ-DI was significantly lower in the intervention group than in the control group (.64±.53 vs 1.36±1.02; P=.026). The intervention group also had better scores than the control group for some quality-of-life dimensions (SF-36 General Health: 53.44±8.73 vs 36.57±22.10, respectively; P=.038; SF-36 Role Physical: 63.89±43.50 vs 17.86±37.40, respectively; P=.023) and pain levels (5.0±10.61 vs 33.38±35.68, respectively; P=.04) at 12 months. The program was well tolerated by all the participants.

CONCLUSIONS

In patients with IMs, the combination of a 4-week standardized rehabilitation program and a personalized, home-based, self-managed rehabilitation program was well tolerated and had a positive medium-term functional effect.

[Usefulness of rehabilitation in inflammatory myopathies]

Rehabilitation, for a long time not recommended, seems today to hold a prominent place within the therapeutic arsenal of inflammatory myopathies. The difficulty of its evaluation, apart from the low prevalence of these diseases, lies in a triple heterogeneity: first that distinguishing the different forms of inflammatory myopathies and the phase where they are active; second, that concerning the endpoint considered to assess the efficiency of the intervention; lastly, the diversity of the rehabilitation programs that can be undertaken. Between 1993 and 2016, about 30 studies estimating the rehabilitation of inflammatory myopathies have been published, among which five randomized controlled trials, four controlled trials, 15 open studies, and seven case reports. All these studies evidence the safety of rehabilitation and some show a significant improvement of the criteria estimating the activity of the disease, its functional impact or the impairment of quality of life and the limitation in daily life activities triggered by the disease. The rehabilitation, whether aerobic, anaerobic or mixed, must today systematically be associated with the pharmaceutic treatment proposed to patients affected by inflammatory myopathies. Other studies are necessary to optimize the rehabilitation methods, to understand their effects and action, and to quantify their impact and provide more trustworthy evidence.

Selected aspects of the current management of myositis

The idiopathic inflammatory myopathies (IIM) are a rare and heterogeneous group of acquired autoimmune muscle disorders, often referred to as 'myositis'. Clinical assessment, together with muscle biopsy findings and autoantibody status are key factors to consider when making a diagnosis of IIM, and in stratification of the 'IIM spectrum' into disease subgroups. Treatment stratified according to serotype (and in the future, likely also genotype) is increasingly being used to take account of the heterogeneity within the IIM spectrum. Subgroup classification is also important in terms of monitoring for complications, such as malignancy and interstitial lung disease. Disease monitoring should include the use of standardized tools such as the IMACS disease activity outcome measures. Other tools such as muscle MRI can be useful in identifying areas of active muscle inflammation. Treatment outcomes in IIM remain unsatisfactory. The evidence base to guide treatment decisions is remarkably limited. In addition to muscle inflammation, a number of noninflammatory cell-mediated mechanisms may contribute to weakness and disability, and for which no specific treatments are currently available.

Physical exercise as a treatment for adult and juvenile myositis

There is growing evidence to support the safety and efficacy of exercise in patients with adult and juvenile idiopathic inflammatory myopathies. Five randomized controlled trials including adult patients with polymyositis and dermatomyositis (DM) and additional open studies have demonstrated reduced impairment and activity limitation as well as improved quality of life. In addition, recent studies have shown reduced disease activity assessed by consensus disease activity measures and reduced expression of genes regulating inflammation and fibrosis. Furthermore, exercise could improve muscle aerobic capacity as shown by increased mitochondrial enzyme activity. These data suggest that intensive aerobic exercise and resistance training could reduce disease activity and inflammation and improve muscle metabolism. Encouraging results have been reported from available open studies including patients with inclusion body myositis (IBM) and juvenile DM, indicating reduced impairment, activity limitation and improved quality of life also in these patients. Larger studies are needed to increase understanding of the effects of exercise in patients with active, recent-onset polymyositis and DM as well as in patients with IBM and juvenile DM.

Proposal for a Candidate Core Set of Fitness and Strength Tests for Patients with Childhood or Adult Idiopathic Inflammatory Myopathies

OBJECTIVE

Currently there are no evidence-based recommendations regarding fitness and strength tests for patients with childhood or adult idiopathic inflammatory myopathies (IIM). This hinders clinicians and researchers in choosing the appropriate fitness- or muscle strength-related outcome measures for these patients. Through a Delphi survey, we aimed to identify a candidate core set of fitness and strength tests for children and adults with IIM.

METHODS

Fifteen experts participated in a Delphi survey that consisted of 5 stages to achieve a consensus. Using an extensive search of published literature and through the work of experts, a candidate core set based on expert opinion and clinimetrics properties was developed. Members of the International Myositis Assessment and Clinical Studies Group were invited to review this candidate core set during the final stage, which led to a final candidate core set.

RESULTS

A core set of fitness- and strength-related outcome measures was identified for children and adults with IIM. For both children and adults, different tests were identified and selected for maximal aerobic fitness, submaximal aerobic fitness, anaerobic fitness, muscle strength tests, and muscle function tests.

CONCLUSION

The core set of fitness- and strength-related outcome measures provided by this expert consensus process will assist practitioners and researchers in deciding which tests to use in patients with IIM. This will improve the uniformity of fitness and strength tests across studies, thereby facilitating the comparison of study results and therapeutic exercise program outcomes among patients with IIM.

The effect of ladder-climbing exercise on atrophy/hypertrophy-related myokine expression in middle-aged male Wistar rats

We investigated the change in myokine expression related to hypertrophy (IL-4, IL-6, IL-10) and atrophy (TNF-α, NFκB, IL-1β) in middle-aged rats after resistance exercise with ladder climbing. 50- and 10-week-old male Wistar rats were randomly assigned to two groups: the sedentary and exercise groups. The exercise groups underwent a ladder-climbing exercise for 8 weeks. While the tibialis anterior muscle mass in the young group significantly increased after the ladder-climbing exercise, the middle-aged group did not show any changes after undergoing the same exercise. To understand the molecular mechanism causing this difference, we analyzed the change in hypertrophy- and atrophy-related myokine levels from the tibialis anterior muscle. After 8 weeks of ladder-climbing exercise, the IL-4 and IL-10 protein levels did not change. However, the IL-6 level significantly increased after exercise training, but the amount of increase in the young training group was higher than in the middle-aged training group. IL-1β and TNF-α as well as NFκB protein levels were significantly higher in the middle-aged group than in the young group. Except for TNF-α, exercise training did not affect IL-1β and NFκB protein levels. The TNF-α level significantly decreased in the middle-aged exercise training group. AMPK and PGC-1α levels also significantly increased after exercise training, but there was no difference between age-related groups. Therefore, 8-week high-intensity exercise training using ladder climbing downregulates the skeletal muscle production of myokine involved in atrophy and upregulates hypertrophic myokine. However, the extent of these responses was lower in the middle-aged than young group.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIM) consist of rare heterogeneous autoimmune disorders that present with marked proximal and symmetric muscle weakness, except for distal and asymmetric weakness in inclusion body myositis. Despite many similarities, the IIM are fairly heterogeneous from the histopathologic and pathogenetic standpoints, and also show some clinical and treatment-response differences. The field has witnessed significant advances in our understanding of the pathophysiology and treatment of these rare disorders. This review focuses on dermatomyositis, polymyositis, and necrotizing myopathy, and examines current and promising therapies.

New insights into the benefits of exercise for muscle health in patients with idiopathic inflammatory myositis

With recommended treatment, a majority with idiopathic inflammatory myopathy (IIM) develop muscle impairment and poor health. Beneficial effects of exercise have been reported on muscle performance, aerobic capacity and health in chronic polymyositis and dermatomyositis and to some extent in active disease and inclusion body myositis (IBM). Importantly, randomized controlled trials (RCTs) indicate that improved health and decreased clinical disease activity could be mediated through increased aerobic capacity. Recently, reports seeking mechanisms underlying effects of exercise in skeletal muscle indicate increased aerobic capacity (i.e. increased mitochondrial capacity and capillary density, reduced lactate levels), activation of genes in aerobic phenotype and muscle growth programs, and down regulation in genes related to inflammation. Altogether, exercise contributes to both systemic and within-muscle adaptations demonstrating that exercise is fundamental to improve muscle performance and health in IIM. There is a need for RCTs to study effects of exercise in active disease and IBM.

SSc management--In person appointments and remote therapy (SMART): a framework for management of chronic hand conditions

The changing health care climate poses unique challenges to managing a chronic and progressive disease like systemic sclerosis (SSc). At our institution, we employ a new model for SSc management that combines "in person" appointments and "remote" therapy (SMART). This program fosters an understanding of the disease process with the goal of improving skills and confidence for self-management and empowering individuals by providing a means of daily self-assessment. Technology is utilized as a means to remotely monitor and assess progress. We present our approach as a framework for long term management of chronic hand conditions. Evidence from a variety of disciplines is cited to support the design and parameters of this model.

Effect of exercise training on skeletal muscle cytokine expression in the elderly

Aging is associated with increased circulating pro-inflammatory and lower anti-inflammatory cytokines. Exercise training, in addition to improving muscle function, reduces these circulating pro-inflammatory cytokines. Yet, few studies have evaluated changes in the expression of cytokines within skeletal muscle after exercise training. The aim of the current study was to examine the expression of cytokines both at rest and following a bout of isokinetic exercise performed before and after 12weeks of resistance exercise training in young (n=8, 20.3±0.8yr) and elderly men (n=8, 66.9±1.6yr). Protein expression of various cytokines was determined in muscle homogenates. The expression of MCP-1, IL-8 and IL-6 (which are traditionally classified as 'pro-inflammatory') increased substantially after acute exercise. By contrast, the expression of the anti-inflammatory cytokines IL-4, IL-10 and IL-13 increased only slightly (or not at all) after acute exercise. These responses were not significantly different between young and elderly men, either before or after 12weeks of exercise training. However, compared with the young men, the expression of pro-inflammatory cytokines 2h post exercise tended to be greater in the elderly men prior to training. Training attenuated this difference. These data suggest that the inflammatory response to unaccustomed exercise increases with age. Furthermore, regular exercise training may help to normalize this inflammatory response, which could have important implications for muscle regeneration and adaptation in the elderly.

Patients with regular physical activity before onset of rheumatoid arthritis present with milder disease

OBJECTIVES

Physical activity has been shown to decrease inflammatory markers; here we investigate the effect on the clinical presentation of rheumatoid arthritis (RA).

METHODS

We used the cases from the population-based EIRA study (N=617), followed in the Swedish Rheumatology Quality Register, calculating the odds of having above median level of 28-joint disease activity score (DAS28), physician assessment, pain (visual-analogue scale (VAS), VAS-pain) and activity limitation (health assessment questionnaire (HAQ)) at diagnosis, as an effect of physical activity 5 years before diagnosis, investigated both in categories and dichotomised.

RESULTS

Dose-response relationships were seen for all measures; the higher the level of physical activity, the lower the likelihood of having outcome measure above median. Further, regular physical activity associated with 42% reduced odds of having DAS28 above median (OR=0.58 (95% CI 0.42 to 0.81)). Effects were similar for VAS-pain (OR=0.62 (95%CI 0.45 to 0.86)) and physician assessment (OR=0.67 (95%CI 0.47 to 0.95)) but not for HAQ. Statistically significant effects were also found both for the combined objective components and the combined subjective components of DAS28.

CONCLUSIONS

Physically active individuals seem to present with milder RA, which adds to the evidence of beneficial effects of physical activity on inflammatory diseases. The observation should be important for both health professionals and individuals seeking to reduce their risk.

Activation of the ubiquitin proteasome pathway in a mouse model of inflammatory myopathy: a potential therapeutic target

OBJECTIVE

Myositis is characterized by severe muscle weakness. We and others have previously shown that endoplasmic reticulum (ER) stress plays a role in the pathogenesis of myositis. The present study was undertaken to identify perturbed pathways and assess their contribution to muscle disease in a mouse myositis model.

METHODS

Stable isotope labeling with amino acids in cell culture (SILAC) was used to identify alterations in the skeletal muscle proteome of myositic mice in vivo. Differentially altered protein levels identified in the initial comparisons were validated using a liquid chromatography tandem mass spectrometry spike-in strategy and further confirmed by immunoblotting. In addition, we evaluated the effect of a proteasome inhibitor, bortezomib, on the disease phenotype, using well-standardized functional, histologic, and biochemical assessments.

RESULTS

With the SILAC technique we identified significant alterations in levels of proteins belonging to the ER stress response, ubiquitin proteasome pathway (UPP), oxidative phosphorylation, glycolysis, cytoskeleton, and muscle contractile apparatus categories. We validated the myositis-related changes in the UPP and demonstrated a significant increase in the ubiquitination of muscle proteins as well as a specific increase in ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL-1) in myositis, but not in muscle affected by other dystrophies or normal muscle. Inhibition of the UPP with bortezomib significantly improved muscle function and also significantly reduced tumor necrosis factor α expression in the skeletal muscle of mice with myositis.

CONCLUSION

Our findings indicate that ER stress activates downstream UPPs and contributes to muscle degeneration and that UCHL-1 is a potential biomarker for disease progression. UPP inhibition offers a potential therapeutic strategy for myositis.

Improvement in health and possible reduction in disease activity using endurance exercise in patients with established polymyositis and dermatomyositis: a multicenter randomized controlled trial with a 1-year open extension followup

OBJECTIVE

To determine the effects of a 12-week endurance exercise program on health, disability, VO2 max, and disease activity in a multicenter randomized controlled trial in patients with established polymyositis (PM) and dermatomyositis (DM), and to evaluate health and disability in a 1-year open extension study.

METHODS

Patients were randomized into a 12-week endurance exercise program group (EG; n = 11) or a control group (CG; n = 10). Assessments of health (Short Form 36 [SF-36]), muscle performance (5 voluntary repetition maximum [5 VRM]), activities of daily living (ADL), patient preference (McMaster Toronto Arthritis Patient Preference Disability Questionnaire), VO2 max, and disease activity (International Myositis Assessment and Clinical Studies criteria of improvement of the 6-item core set) were performed at 0 and 12 weeks. Disability assessments were performed again at 52 weeks in an open extension period. All assessments were performed by blinded observers.

RESULTS

The EG improved compared to the CG in SF-36 physical function and vitality (P = 0.010 and P = 0.046, respectively), ADL score (P = 0.035), 5 VRM (P = 0.026), and VO2 max (P = 0.010). More patients in the EG (7 of 11) were responders with reduced disease activity compared to none in the CG (P = 0.002). Correlations between VO2 max and SF-36 physical function were 0.90 and 0.91 at 0 and 12 weeks, respectively (P < 0.05). The EG improvement in 5 VRM was sustained up to 52 weeks compared to baseline (5.7 kg; P < 0.001), but not in ADL score or SF-36.

CONCLUSIONS

Endurance exercise improves health and may reduce disease activity in patients with established PM/DM. This potentially could be mediated through improved aerobic fitness. The results also indicate sustained muscle strength up to 1 year after a supervised program.

Mechanical-stretch of C2C12 myoblasts inhibits expression of Toll-like receptor 3 (TLR3) and of autoantigens associated with inflammatory myopathies

Recent studies in patients suffering from inflammatory autoimmune myopathies suggested that moderate exercise training improves or at least stabilizes muscle strength and function without inducing disease flares. However, the precise mechanisms involved in this beneficial effect have not been extensively studied. Here we used a model of in vitro stretched C2C12 myoblasts to investigate whether mechanical stretch could influence myoblast proliferation or the expression of proinflammatory genes. Our results demonstrated that cyclic mechanical stretch stimulated C2C12 cell cycling and early up-regulation of the molecules related to mechanical-stretch pathway in muscle (calmodulin, nNOS, MMP-2, HGF and c-Met). Unexpectedly, mechanical stretch also reduced the expression of TLR3 and of proteins known to represent autoantigens in inflammatory autoimmune myopathies (Mi-2, HRS, DNA-PKcs, U1-70). Interestingly, stimulation or inhibition of calmodulin, NOS, HGF or c-Met molecules in vitro affected the expression of autoantigens and TLR3 proteins confirming their role in the inhibition of autoantigens and TLR3 during mechanical stretch. Overall, this study demonstrates for the first time that mechanical stretch could be beneficial by reducing expression of muscle autoantigens and of pro-inflammatory TLR3 and may provide new insight to understand how resistance training can reduce the symptoms associated with myositis.

Helpful or harmful? Potential effects of exercise on select inflammatory conditions

Inflammation has been characterized as a double-edged sword, requiring a balance between health as maintained by regular exercise and activities that would exacerbate inflammatory diseases. The influence of exercise on inflammation is complex and has been widely studied in both healthy patient populations as well as populations of patients with many inflammatory and/or autoimmune rheumatic diseases. Inflammatory markers can be affected by the type of exercise and muscle contraction, as well as the intensity, duration, and consistency of the exercise sessions. Because of these potentially important effects, many members of the general public, as well as some clinicians, believe that exercise could exacerbate symptoms and accelerate the progression of such conditions. The effects of different types of exercise have been studied among patients with inflammatory conditions such as ankylosing spondylitis, systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, fibromyalgia, and idiopathic inflammatory myopathies, as well as congestive heart failure, type 2 diabetes mellitus, and metabolic syndrome, which are considered low-grade systemic inflammatory diseases. This review will help exercise professionals and clinicians understand the effects of exercise on inflammatory markers, as well as offer effective treatment options and recommendations for patients exercising with rheumatic or inflammatory conditions.