Aerobic capacity and disease activity in children, adolescents and young adults with juvenile idiopathic arthritis (JIA)

Physical activity as a promising alternative for young people with juvenile idiopathic arthritis: Towards an evidence-based prescription

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in young people. Although biologics now enable most children and adolescents with JIA to enjoy clinical remission, patients present lower physical activity and spend more time in sedentary behavior than their healthy counterparts. This impairment probably results from a physical deconditioning spiral initiated by joint pain, sustained by apprehension on the part of both the child and the child's parents, and entrenched by lowered physical capacities. This in turn may exacerbate disease activity and lead to unfavorable health outcomes including increased risks of metabolic and mental comorbidities. Over the past few decades, there has been growing interest in the health benefits of increased overall physical activity as well as exercise interventions in young people with JIA. However, we are still far from evidence-based physical activity and / or exercise prescription for this population. In this review, we give an overview of the available data supporting physical activity and / or exercise as a behavioral, non-pharmacological alternative to attenuate inflammation while also improving metabolism, disease symptoms, poor sleep, synchronization of circadian rhythms, mental health, and quality of life in JIA. Finally, we discuss clinical implications, identify gaps in knowledge, and outline a future research agenda.

Description of physical activity in children with juvenile idiopathic arthritis using accelerometry

OBJECTIVES

Juvenile idiopathic arthritis (JIA) can lead to functional impotence and reduced physical activity (PA) in patients. The objective of this study was to monitor the daily PA of children aged 6-18 years with JIA using accelerometry based on disease activity and individual abilities, and to compare this with age recommendations.

METHODS

Patients volunteering for the study wore an accelerometer for 7 consecutive days; data were evaluated using a wGT3X ActiGraph™. The 2010 World Health Organization (WHO) recommendations were used for comparison.

RESULTS

We collected accelerometry data for 24 patients of the University Hospital Center (UHC) of Besançon. Only two patients did not reach the recommendations of moderate-to-vigorous PA (MVPA). Time spent in MVPA was negatively correlated with age, BMI, number of joints with active arthritis, JADAS score, and visual analogue pain assessment (VAPA). Patients with active disease, those with upper extremity pain, and female patients had significantly lower PA scores.

CONCLUSIONS

Almost all of the patients of the UHC of Besançon who accepted the study reached the WHO recommendations. Having an active disease, having painful upper limbs, or being a girl is associated with decreased PA.

Secondary consequences of juvenile idiopathic arthritis in children and adolescents with knee involvement: physical activity, adiposity, fitness, and functional performance

OBJECTIVE

Secondary consequences of juvenile idiopathic arthritis (JIA) may impact long-term health outcomes. This study examined differences in physical activity, cardiorespiratory fitness, adiposity, and functional performance in children and adolescents with JIA compared to their typically developing (TD) peers.

METHODS

Participants with JIA (n = 32; 10-20 years old) and their TD peers (n = 35) volunteered for assessments of: daily moderate-to-vigorous physical activity (MVPA, body-worn accelerometer); peak oxygen consumption (VO_{2 Peak}, incremental bike test); fat mass index (FMI, dual-energy X-ray absorptiometry); and triple-single-leg-hop (TSLH) distance. Statistical analyses were performed in R using four linear mixed-effect models with Bonferroni adjustment (⍺ = 0.0125). Fixed effects were group, sex, and age. Participant clusters based on sex and age (within 1.5 years) were considered as random effects.

RESULTS

Participants with JIA displayed lower mean daily MVPA than their TD peers [p = 0.006; β (98.75% CI); -21.2 (-40.4 to -2.9) min]. VO_{2 Peak} [p = 0.019; -1.4 (-2.5 to -0.2) ml/kg/min] decreased with age. Females tended to have lower V_{O2 Peak} [p = 0.045; -6.4 (-13.0 to 0.4) ml/kg/min] and greater adiposity [p = 0.071; 1.4 (-0.1 to 3.0) kg/m²] than males.

CONCLUSION

The findings support the need for strategies to promote MVPA participation in children and adolescents with JIA. Sex and age should be considered in research on the consequences of JIA.

Physical Fitness in Patients With Oligoarticular and Polyarticular Juvenile Idiopathic Arthritis Diagnosed in the Era of Biologics: A Controlled Cross-Sectional Study

OBJECTIVE

To perform a comprehensive evaluation of and identify correlates for physical fitness in consecutive patients with juvenile idiopathic arthritis (JIA) who have been diagnosed in the era of biologics and to compare the results with those obtained in healthy controls.

METHODS

The study cohort included 60 patients with JIA (50 girls) ages 10-16 years and 60 age- and sex-matched controls. The JIA group included 30 patients with persistent oligoarticular JIA and 30 patients with extended oligoarticular or polyarticular disease. Measures of physical fitness included cardiorespiratory fitness (CRF) by peak oxygen uptake (Vo_2peak ) during a continuous graded treadmill exercise test, muscle strength by isokinetic and isometric knee and hand grip evaluations, and bone mineral density (BMD) and body composition by dual-energy x-ray absorptiometry. Physical activity was assessed by accelerometry.

RESULTS

Forty-two percent of the patients were being treated with biologic drugs. Patients with JIA demonstrated lower muscle strength and total body BMD compared to controls, but there were no differences in CRF and body composition. Physical fitness was comparable between the persistent oligoarticular and extended oligoarticular/polyarticular-JIA groups. In patients with JIA, we identified associations between higher vigorous physical activity and higher CRF and muscle strength, but did not find any association between physical fitness and disease variables.

CONCLUSION

In this cohort of patients with JIA, we found suboptimal muscle strength and BMD compared to controls, but no differences in CRF and body composition. Vigorous physical activities appeared important for optimizing muscle strength and CRF in patients with JIA; the importance of such activities should be highlighted in patient education.

The aerobic capacity in patients with antisynthetase syndrome and dermatomyositis

BACKGROUND

This study was aimed at evaluating the aerobic capacity of patients with antisynthetase syndrome (ASS) and dermatomyositis (DM) and analyzing possible relationships between aerobic capacity and disease status, cardiovascular diseases and their risk factors.

METHODS

The study was a cross-sectional, single-center study that assessed the aerobic capacity of 22 women (13 with DM and 9 with ASS) who were matched by age and body mass index to 17 healthy women (control group). The aerobic capacity (oxygen uptake [VO₂ peak], anaerobic threshold, respiratory compensation point and time-to-exhaustion) was evaluated using the cardiopulmonary treadmill test. Disease status was assessed using International Myositis Assessment & Clinical Studies Group (IMACS) set scores.

RESULTS

The patients had low IMACS parameters that showed low or absent disease activity. The distribution of cardiovascular diseases and their risk factors was similar between the patients and the control group (P >  0.05) at the time of the analysis. The patients with DM and the control group had similar aerobic capacity. However, the patients with ASS exhibited significantly reduced aerobic capacity (relative VO₂ peak, anaerobic threshold, respiratory compensation point and time to exhaustion) when compared to the control group. In addition, patients with ASS had a lower anaerobic threshold compared to the DM group. There were no significant relationships between the aerobic capacity and disease status, cardiovascular diseases and their risk factors.

CONCLUSION

In contrast to DM patients and healthy individuals, patients with stable ASS have significantly impaired aerobic capacity, which is unlikely to be totally explained by traditional cardiovascular diseases, their risk factors and disease status. Further studies are needed to corroborate our data and to clarify the cause of this reduced aerobic capacity in ASS.

Impaired Muscular Fat Metabolism in Juvenile Idiopathic Arthritis in Inactive Disease

Objectives: The objective of this study was to evaluate muscular metabolic function in children with inactive juvenile idiopathic arthritis (JIA).

Methods: Fifteen children with inactive JIA and fifteen healthy controls were matched by sex, biological age, and Tanner stage. Participants completed a submaximal incremental exercise test to determine their fat and carbohydrate oxidation rates.

Results: Between the two groups, heart rate values and carbohydrate oxidation rates were the same, regardless of the relative intensity of exercise. Lipid oxidation rates were lower in JIA patients, regardless of the percentage of VO₂ peak (p < 0.05). Respiratory exchange ratios beyond 50% of VO₂ peak were higher in patients with JIA (p < 0.05). Respective maximal fat oxidation rates (MFO) for controls and children with JIA were 218.7 ± 92.2 vs. 157.5 ± 65.9 mg ⋅ min^-1 (p = 0.03) and 4.9 ± 1.9 vs. 3.4 ± 1.2 mg ⋅ min^-1 ⋅ kg^-1 (p = 0.04). There was no difference between the two groups in heart rate, percentage of VO₂ peak, or power of exercise to achieve MFO. Controls reached their MFO at an exercise power significantly higher than did JIA subjects (42.8 ± 16.8 and 31.9 ± 9.8 W, p = 0.004).

Conclusion: Children with JIA show metabolic disturbance during exercise, even when the disease is considered inactive. This disturbance is seen in a lower lipid oxidation rate during submaximal exercise.

Measurement properties and performance of an eight-minute submaximal treadmill test in patients with juvenile idiopathic arthritis: a controlled study

BACKGROUND

Poor cardiorespiratory fitness is previously reported in patients with juvenile idiopathic arthritis (JIA) measured both by maximal and submaximal exercise tests, but a submaximal exercise test with acceptable measurement properties is currently lacking for both clinical and research purposes in this patient population. The objectives of this study were to evaluate the measurement properties and performance of a submaximal treadmill test in patients with JIA, and to compare the results with those obtained in controls.

METHODS

Fifty-nine patients (50 girls), aged 10-16 years, with oligo- (n = 30) and polyarticular (n = 29) JIA, and 59 age- and sex-matched controls performed an eight-minute submaximal treadmill test for estimating peak oxygen uptake (VO2peak) followed by a maximal treadmill test measuring VO2peak directly. During the submaximal treadmill test, the study participants walked with no inclination at a speed between 3.2-7.2 km/h for four minutes, and then continued to walk at the same speed for four minutes with five % inclination. VO2peak was directly measured during a continuous graded exercise test on treadmill until exhaustion. Thirty-seven patients participated in the evaluation of the reliability. Criterion validity and reliability were evaluated with interclass correlation coefficient (ICC); measurement errors by Bland-Altman plot, standard error of measurement and smallest detectable change.

RESULTS

In patients with JIA, the ICC (95% CI) for criterion validity was acceptable at group level 0.71 (0.51, 0.82), but not at individual level. The test-retest reliability and inter-rater reliability were acceptable at individual (0.84 (0.71, 0.91) and 0.92 (0.83, 0.96), respectively) and group levels (0.91 (0.83, 0.96) and 0.96 (0.91, 0.98), respectively). The measurement errors (for test-retest reliability/inter-rater reliability) were large. Bland-Altman plots showed no systematic differences, but a large variability for both the validity and reliability. The performance of and estimated VO2peak from the submaximal test were not associated with disease variables and were comparable between patients and controls.

CONCLUSION

The submaximal treadmill test is valid for use in patients with JIA on group level, but not on individual level. The reliability is acceptable. Due to large measurement errors, the submaximal treadmill test is not optimal for use in daily clinical practice to estimate VO2peak in individual patients.

'It might hurt, but you have to push through the pain': Perspectives on physical activity from children with juvenile idiopathic arthritis and their parents

Our primary objective was to gather perspectives of children diagnosed with juvenile idiopathic arthritis (JIA) and their parents as they relate to physical activity (PA) participation. To do so, we conducted a study on 23 children diagnosed with JIA and their parents ( N = 29). We used convenience sampling to recruit participants and qualitative method- logies (one-on-one semi-structured interviews). We adopted a five-step framework analysis to categorize data into themes. Children and their parents described factors that act to facilitate or hinder PA participation. Pain was the most commonly highlighted PA barrier described by children and their parents. However, children who were newly diagnosed with JIA and their parents were more likely to highlight pain as a barrier than were child/parent dyads where children had been previously diagnosed.

Premature subclinical atherosclerosis in children and young adults with juvenile idiopathic arthritis. A review considering preventive measures

Many studies show that Juvenile Idiopathic Arthritis (JIA) is associated with early subclinical signs of atherosclerosis. Chronic inflammation per se may be an important driver but other known risk factors, such as dyslipidemia, hypertension, insulin insensitivity, a physically inactive lifestyle, obesity, and tobacco smoking may also contribute substantially. We performed a systematic review of studies through the last 20 years on early signs of subclinical atherosclerosis in children and adolescents with JIA with the purpose of investigating whether possible risk factors, other than inflammation, were considered.We found 13 descriptive cross sectional studies with healthy controls, one intervention study and two studies on adults diagnosed with JIA. Only one study addressed obesity, and physical activity (PA) has only been assessed in one study on adults with JIA and only by self-reporting. This is important as studies on PA in children with JIA have shown that most patients are less physically active than their healthy peers, and as physical inactivity in several large studies of normal schoolchildren is found to be associated with increased clustering of risk factors for cardiovascular disease. It is thus possible that an inactive lifestyle in patients with JIA is an important contributor to development of the subclinical signs of atherosclerosis seen in children with JIA, and that promotion of an active lifestyle in childhood and adolescence may diminish the risk for premature atherosclerotic events in adulthood.

Reduced physical activity in children and adolescents with Juvenile Idiopathic Arthritis despite satisfactory control of inflammation

BACKGROUND

Vascular health is of concern in patients with Juvenile Idiopathic Arthritis (JIA) since Rheumatoid Arthritis (RA) epidemiologically has a well-described association with premature development of atherosclerosis. Chronic inflammation with persisting systemic circulating inflammatory proteins may be a cause of vascular damage, but general physical inactivity could be an important contributor. Pain and fatigue are common complaints in patients with JIA and may well lead to an inactive sedentary lifestyle. For this reason we assessed the physical activity (PA) objectively in patients with moderate to severe Juvenile Idiopathic Arthritis (JIA) in comparison with gender and age matched healthy schoolchildren, and looked for associations between PA and features of JIA.

METHODS

One hundred thirty-three patients, 7-20 years of age, participated. Disease activity, disability, functional ability, and pain were assessed and PA was measured by accelerometry through 7 days and compared to PA in age- and gender-matched healthy schoolchildren.

RESULTS

We found a significantly lower level of PA in patients compared to gender- and age-matched healthy schoolchildren both in average activity (counts per minute, cpm) (475.6 vs. 522.7, p = 0.0000018) and in minutes per day spent with cpm >1500 (67.9 vs. 76.4, p = 0.0000014), with cpm >2000 (moderate physical activity) (48.4 vs. 52.8, p = 0.0001, and with cpm >3000 (high physical activity) (24.7 vs. 26.5, p = 0.00015). A negative association (β = -0.213, p = 0.014) between active disease in weight bearing joints and high physical activity remained the only significant association between disease related factors and PA. Of the girls 19% and of the boys 45% (vs. 39% and 61% in the reference group) met standards set by Danish Health Authorities for daily PA in childhood.

CONCLUSION

Children and adolescents with JIA are less physically active than their healthy peers and less active than recommended for general health by the Danish Health Authorities. This is not explained by pain or objective signs of inflammation. When inflammation has been curbed, restoration of an active healthy lifestyle should be highly prioritized.

Design and acceptance of Rheumates@Work, a combined internet-based and in person instruction model, an interactive, educational, and cognitive behavioral program for children with juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a chronic rheumatic disease. Patients suffer daily discomforts such as pain, fatigue, stiffness, and mood disturbances. Their exercise capacity is decreased to a variable degree and physical activity levels may be impaired. To prevent long-term cardiovascular risks associated with JIA and medication, it is important to encourage physical activity. To achieve this we developed Rheumates@Work (R@W), a combined internet-based and in person instruction model, an interactive, educational, and cognitive behavioral program. The aim of this study is twofold: to describe the theoretical background and design of R@W based on Pender's Health Promotion Model, and to assess its acceptance.

METHODS

We enrolled 8 to 13-year-old JIA patients, from 3 outpatients clinics in The Netherlands, in R@W. Inclusion criteria were a low disease activity (VAS physician <20 mm), comprehension of the Dutch language and absence of relevant co-morbidity. We assessed acceptance by measuring the participants' commitment to the program, the level of interaction on patient's initiative (f.e. mails send by the patient), technical aspects and satisfaction. Commitment was defined as the percentage of participants that completed the assignments and how much encouragement the participants needed for this. Satisfaction was measured with an anonymous questionnaire concerning f.e. time investment and perceived benefits. Costs were monitored.

RESULTS

Of the 64 patients we enrolled, 23 boys and 41 girls, 93.8 % completed the program. Participant-initiated interaction was seen in 10.7 %, 24.7 % send a mail because of technical problems. Eighty-two percent of the participants and 99 % of the parents liked the program, and 85 % of the participants indicated that they had learnt something, or quite a lot. Development costs of the program were low.

CONCLUSION

The HPM is suitable for a behavioral intervention program such as R@W. Acceptance and satisfaction of R@W were high and the costs of the program were low.

TRIAL NUMBER

ISRCTN92733069.

Juvenile idiopathic arthritis and physical activity: possible inflammatory and immune modulation and tracks for interventions in young populations

Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease characterized by persistent joint inflammation that manifests as joint pain and swelling and limited range of joint motion. In healthy subjects, the literature reports that physical activity has an anti-inflammatory effect. In JIA patients, exercise could be used as a therapeutic tool to counteract disease-related inflammation and thereby improve clinical symptoms, although transient flare of pain could be the price to pay. Indeed, in patients with a chronic inflammatory disease, physical activity is prone to exacerbate underlying inflammatory stress. Physical activity improves quality of life and symptoms in JIA patients, but the mechanisms of action remain unclear. This review focuses on the mechanisms underlying exercise-induced immune and hormonal changes. Data on the impact of acute and chronic physical activities on the secretion of hormones and other molecules such as miRNA or peptides involved in the inflammatory process in JIA was compiled and summarized, and the key role of the biological effect of muscle-derived interleukin 6 in the exercise-induced modulation of pro/anti-inflammatory balance is addressed. We also go on to review the effect of training and type of exercise on cytokine response. This review highlights the beneficial effect of physical exercise in children with JIA and potential effect of exercise on the balance between pro- and anti-inflammatory response.

Disease progression into adulthood and predictors of long-term active disease in juvenile idiopathic arthritis

OBJECTIVES

To describe disease activity 30 years after disease onset in a previously studied cohort of patients with juvenile idiopathic arthritis (JIA) and reveal predictors of long-term active disease.

METHODS

Patients with JIA, first referred 1980-1985 and re-examined 15 and 23 years after onset, were invited to attend. All 176 patients were assessed by questionnaires. Patients with signs of active disease at 15 years or later also came to a clinical re-examination (n=90). Disease activity was assessed by the clinical juvenile arthritis disease activity score (JADAS3) and by the criteria for remission in JIA, and health status by Health Assessment Questionnaire (HAQ) and Medical Outcome Study 36-item Short Form Health Survey (SF-36).

RESULTS

At 30-year follow-up, 59% of the patients were in clinical remission off medication, 7% were in remission on medication and 34% had active disease. 70% of the patients were in the same category of disease activity at 15 and 30 years. The JADAS3 was ≤2.0 in 54%, 2.1-4.5 in 18% and >4.5 in 28%. HLA-DRB1*01, physician's global assessment and a short total time in remission at 15 years, predicted active disease. Physician's global assessment also predicted a JADAS3 >4.5. From 15 to 30 years (n=90), physician's global assessment, number of active joints, erythrocyte sedimentation rate and C reactive protein improved significantly, but patient's global assessment, HAQ and SF-36 did not.

CONCLUSIONS

41% of the patients with JIA had active disease or were on medication after 30 years and 28% had a high symptom state. Remission rates and patient-reported health status at 15 years were comparable with rates at 30 years.

Recent developments in disease activity indices and outcome measures for juvenile idiopathic arthritis

There has been a concerted and important international effort to develop and validate disease activity and outcome instruments specific to JIA in recent years. This review aims to describe the disease assessment indices important to routine clinical care and integral to the design of outcome studies and clinical trials in JIA. In view of the increasing number of JIA clinical studies and clinical trials, together with a number of national and international paediatric biologic registers, it is important that knowledge of these new outcome measures is widespread, such that results can be placed in a meaningful context.