Design of the muscles in motion study: a randomized controlled trial to evaluate the efficacy and feasibility of an individually tailored home-based exercise training program for children and adolescents with juvenile dermatomyositis

Updates on Juvenile Dermatomyositis from the Last Decade: Classification to Outcomes

Juvenile dermatomyositis (JDM) is a heterogeneous disease with new classification criteria and updates in myositis-specific autoantibody and myositis-associated antibody groups. There are many validated assessment tools for assessing disease activity in JDM. Future studies will optimize these tools and improve feasibility in clinical and research contexts. Genetic and environmental risk factors, mechanisms of muscle pathology, role of interferon, vascular markers, and changes in immune cells provide insights to JDM pathogenesis. Outcomes have improved, but chronic disease, damage, and mortality highlight the need for better outcome predictors and treatments. Increased collaboration of stakeholders may help overcome research barriers and improve JDM treatment.

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.

Treatment of Juvenile Dermatomyositis: An Update

The idiopathic inflammatory myopathies of childhood consist of a heterogeneous group of autoimmune diseases characterised by proximal muscle weakness and pathognomonic skin rashes. The overall prognosis of juvenile myositis has improved significantly over recent years, but the long-term outcome differs substantially from patient to patient, suggestive of distinct clinical phenotypes with variable responses to treatment. High doses of corticosteroids remain the cornerstone of therapy along with other immunosuppressant therapies depending on disease severity and response. The advent of biological drugs has revolutionised the management of various paediatric rheumatologic diseases, including inflammatory myopathies. There are few data from randomised controlled trials to guide management decisions; thus, several algorithms for the treatment of juvenile myositis have been developed using international expert opinion. The general treatment goals now include elimination of active disease and normalisation of physical function, so as to preserve normal growth and development, and to prevent long-term damage and deformities. This review summarises the newer and possible future therapies of juvenile inflammatory myopathies, including evidence supporting their efficacy and safety.

Recent advances in juvenile idiopathic inflammatory myopathies

PURPOSE OF REVIEW

Ongoing research continues to advance our understanding of the juvenile idiopathic inflammatory myopathies (JIIMs). We review the recent contributions from the published literature about the classification, pathogenesis, assessment, and treatment of JIIMs in basic and translational science and clinical research in 2013 through early 2014.

RECENT FINDINGS

Large registries, such as the Childhood Arthritis and Rheumatology Research Alliance registry, are conducting trials to enhance our understanding of JIIMs. Ultraviolet radiation exposure 1 month prior to juvenile dermatomyositis (JDM) may trigger the onset of disease. Myositis-specific autoantibodies define clinical phenotypes in JIIMs. MRI is useful in diagnosing JDM and may be used as a disease assessment tool. Type 1 interferon genes and proteins are increasing in use as disease assessment tools, but larger, prospective, validation studies are needed. Moderate-to-intense physical activity is effective in increasing the aerobic capacity of JDM patients in remission. New criteria developed by the Paediatric Rheumatology International Trials Organization for classifying inactive disease in JDM have practical applicability to the current clinical practice and clinical trials as even after 16.8 years of symptom onset, over half of JDM patients still have active disease.

SUMMARY

There has been significant progress in understanding the clinical characteristics, diagnostic workup, treatment, disease assessment, and prognosis of JIIM patients, but more prospective treatment trials are needed, especially in light of the paucity of the current biologic treatment agents available.

Update in juvenile myositis

PURPOSE OF REVIEW

This update on childhood idiopathic inflammatory myopathies (IIMs) reviews recent progress in the field of translational science and clinical research over the past 12-18 months.

RECENT FINDINGS

Several new studies, including results from the international genome-wide association study, point to abnormalities of the adaptive immune system in childhood IIMs. Circulating T-follicular helper cells promote plasma cell differentiation and have been found in high levels in juvenile dermatomyositis (JDM), which may account the frequency of autoantibodies seen in this disease. One of the latest to be identified in JDM targets the protein NXP-2 and is associated with an increased risk of calcinosis in young patients. The first randomized controlled clinical trial in refractory adult and childhood IIMs was reported this year. B-cell depletion with the anti-CD20 antibody, rituximab, failed to achieve its primary end point, but patients with JDM did show good improvement in disease activity. A new international definition of disease remission in JDM has been agreed, which will aid disease assessment in future therapeutic trials.

SUMMARY

The challenges of studying a rare disease such as JDM have been overcome by several collaborative studies and have led to significant progress in understanding the cause, treatment and prognosis of childhood IIMs.

Design of a cross-sectional study on physical fitness and physical activity in children and adolescents after burn injury

Background

Burn injuries have a major impact on the patient’s physical and psychological functioning. The consequences can, especially in pediatric burns, persist long after the injury. A decrease in physical fitness seems logical as people survive burn injuries after an often extensive period of decreased activity and an increased demand of proteins leading to catabolism, especially of muscle mass. However, knowledge on the possibly affected levels of physical fitness in children and adolescents after burn injury is limited and pertains only to children with major burns. The current multidimensional study aims to determine the level of physical fitness, the level of physical activity, health-related quality of life and perceived fatigue in children after a burn injury. Furthermore, interrelations between those levels will be explored, as well as associations with burn characteristics.

Methods/design

Children and adolescents in the age range of 6 up to and including 18 years are invited to participate in this cross-sectional descriptive study if they have been admitted to one of the three Dutch burn centers between 6 months and 5 years ago with a burn injury involving at least 10% of the total body surface area and/or were hospitalized ≥ 6 weeks. Physical fitness assessments will take place in a mobile exercise lab. Quantitative measures of cardiorespiratory endurance, muscular strength, body composition and flexibility will be obtained. Outcomes will be compared with Dutch reference values. Physical activity, health-related quality of life and fatigue will be assessed using accelerometry and age-specific questionnaires.

Discussion

The findings of the current study will contribute to a better understanding of the long-term consequences of burn injury in children and adolescents after burns. The results can guide rehabilitation to facilitate a timely and optimal physical recovery.

Trial registration

The study is registered in the National Academic Research and Collaborations Information System of the Netherlands (OND1348800).