Feasibility and safety of a 6-month exercise program to increase bone and muscle strength in children with juvenile idiopathic arthritis

Background: Arthritis in childhood can be associated with muscle weakness around affected joints, low bone mass and low bone strength. Exercise is recognized as an important part of management of children with juvenile idiopathic arthritis (JIA) but the exercise prescription to best promote bone and muscle health is unknown. We therefore aimed to: 1. assess feasibility and safety of a 6-month home- and group-based exercise program for children with JIA; 2. estimate the effect of program participation on bone mass and strength, muscle function and clinical outcomes and 3. determine if any positive changes in bone and muscle outcomes are maintained 6 months later. Methods: We recruited 24 children with JIA who were part of the Linking Exercise, Physical Activity and Pathophysiology in Childhood Arthritis (LEAP) study to participate in a 6-month home-based exercise program involving jumping and handgrip exercises, resistance training and one group exercise session per month. We assessed lumbar spine bone mass (dual energy X-ray absorptiometry), distal tibia and radius bone microarchitecture and strength (high-resolution peripheral quantitative computed tomography), muscle function (jumping mechanography, dynamometry) and clinical outcomes (joint assessment, function, health-related quality of life) at baseline, 6- and 12-months. Adherence was assessed using weekly activity logs. Results: Thirteen children completed the 6-month intervention. Participants reported 9 adverse events and post-exercise pain was rare (0.4%). Fatigue improved, but there were no other sustained improvements in muscle, bone or clinical outcomes. Adherence to the exercise program was low (47%) and decreased over time. Conclusion: Children with JIA safely participated in a home-based exercise program designed to enhance muscle and bone strength. Fatigue improved, which may in turn facilitate physical activity participation. Prescribed exercise posed adherence challenges and efforts are needed to address facilitators and barriers to participation in and adherence to exercise programs among children with JIA. Trial registration: Data of the children with JIA are from the LEAP study (Canadian Institutes of Health Research (CIHR; GRANT# 107535). http://www.leapjia.com/

Predicting which children with juvenile idiopathic arthritis will not attain early remission with conventional treatment: Results from the Reacch-out cohort

Objective. To estimate the probability of early remission with conventional treatment for each child with juvenile idiopathic arthritis (JIA). Children with a low chance of remission may be candidates for initial treatment with biologics or triple disease-modifying antirheumatic drugs (DMARD). Methods. We used data from 1074 subjects in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) cohort. The predicted outcome was clinically inactive disease for ≥ 6 months starting within 1 year of JIA diagnosis in patients who did not receive early biologic agents or triple DMARD. Models were developed in 200 random splits of 75% of the cohort and tested on the remaining 25% of subjects, calculating expected and observed frequencies of remission and c-index values. Results. Our best Cox logistic model combining 18 clinical variables a median of 2 days after diagnosis had a c-index of 0.69 (95% CI 0.67-0.71), better than using JIA category alone (0.59, 95% CI 0.56-0.63). Children in the lowest probability decile had a 20% chance of remission and 21% attained remission; children in the highest decile had a 69% chance of remission and 73% attained remission. Compared to 5% of subjects identified by JIA category alone, the model identified 14% of subjects as low chance of remission (probability \u3c 0.25), of whom 77% failed to attain remission. Conclusion. Although the model did not meet our a priori performance threshold (c-index \u3e 0.70), it identified 3 times more subjects with low chance of remission than did JIA category alone, and it may serve as a benchmark for assessing value added by future laboratory/imaging biomarkers

The Canadian English and French versions of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR).

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Canadian varieties of English and French. The reading comprehension of the questionnaires were tested in a probe sample of ten parents and ten JIA patients for Canadian English and other ten parents and ten JIA patients for Canadian French. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the 3 Likert assumptions, floor/ceiling effects, internal consistency, Cronbach's alpha, interscale correlations, test-retest reliability and construct validity (convergent and discriminant validity). A total of 208 JIA patients (2.9% systemic, 41.8% oligoarticular, 27.9% RF negative polyarthritis, 27.4% other categories) and 152 healthy children, were enrolled at two paediatric rheumatology centres. The JAMAR components discriminated well healthy subjects from JIA patients. Notably, there was no significant difference between the healthy subjects and their affected peers in the psychosocial quality of life variable. All JAMAR components revealed good psychometric performances. In conclusion, the Canadian English and French versions of the JAMAR are valid tools for the assessment of children with JIA and are suitable for use both in routine clinical practice and clinical research

A new Canadian inception cohort for juvenile idiopathic arthritis: The Canadian Alliance of Pediatric Rheumatology Investigators Registry.

OBJECTIVES: The aim was to describe the design, methods and initial findings of a new Canadian inception cohort of children with JIA, The Canadian Alliance of Pediatric Rheumatology Investigators (CAPRI) JIA Registry. METHODS: The CAPRI JIA Registry was started in 2017 to collect information prospectively on children enrolled within 3 months of JIA diagnosis across Canada. The registry has a non-traditional modular design, with no artificially set times for registry visits to occur, streamlined multi-method data collection that requires 2-4 min per visit, and reports cumulative incidence of treatments, outcomes and adverse events calculated by Kaplan-Meier survival methods. RESULTS: A total of 166 patients, enrolled a median of 6 weeks after JIA diagnosis at 10 centres, were included. The median age at diagnosis was 9 years [interquartile range (IQR) 3, 13], 61% were female and 51% had oligoarticular JIA. The median three-variable clinical Juvenile Arthritis Disease Activity Score was 6.5 (IQR 4, 10) at enrolment, and the median time to first attainment of clinically inactive disease (CID) was 24 weeks (by 1 year, 81%). Within 1 year of diagnosis, 70% of patients had started a DMARD and 35% a biologic agent. The rates of adverse events and serious adverse events were 60 and 5.8 per 100 patient-years, respectively. CONCLUSION: This streamlined and flexible registry minimizes the burden of data collection and interference with clinic operations. Initial findings suggest that treatments for newly diagnosed patients with JIA in Canada have intensified, and now 81% of patients attain CID within 1 year of diagnosis

Real-World Effectiveness of Common Treatment Strategies for Juvenile Idiopathic Arthritis: Results From a Canadian Cohort.

OBJECTIVE: Undervaluing the effectiveness of conventional treatments may lead to overtreatment with biologic medications in children with juvenile idiopathic arthritis (JIA). Using data from a nationwide inception cohort and strict methods to control bias, the aim of our study was to estimate the real-world effectiveness of simple JIA treatment strategies recommended in current guidelines. METHODS: Children with JIA who were recruited at 16 Canadian centers from 2005 to 2010 were followed for up to 5 years. For each child, all observed treatment changes over time were assessed by independent physicians using prospectively collected data and published response criteria. Success was defined as attainment of inactive disease or maintenance of this state when stepping down treatment; minimally active disease was deemed acceptable for children with polyarticular JIA. Success rates were calculated for treatments tried ≥25 times, and logistic regression analysis identified features associated with success. RESULTS: A total of 4,429 treatment episodes were observed in 1,352 children. Nonsteroidal antiinflammatory drug (NSAID) monotherapy was attempted 697 times, mostly as initial treatment wheninvolved, with a 54.4% success rate (95% confidence interval [95% CI] 50.3-58.6). NSAIDs plus joint injections had a 64.7% success rate (95% CI 59.8-69.7). Adding methotrexate to NSAIDs and/or joint injections (attempted 566 times) had a 60.5% success rate (95% CI 55.7-65.3). In adjusted analyses, each additional active joint reduced chances of success for treatment with NSAIDs (odds ratio [OR] 0.90 [95% CI 0.85-0.94]) and for methotrexate combinations (OR 0.96 [95% CI 0.94-0.99]). Each additional year after disease onset reduced chances of success for treatment with methotrexate combinations (OR 0.83 [95% CI 0.72-0.95]). CONCLUSION: These real-world effectiveness estimates show that conventional nonbiologic treatment strategies that are recommended in current guidelines are effective in achieving treatment targets in many children with JIA

Growth and weight gain in children with juvenile idiopathic arthritis: results from the ReACCh-Out cohort

Background: With modern treatments, the effect of juvenile idiopathic arthritis (JIA) on growth may be less than previously reported. Our objective was to describe height, weight and body mass index (BMI) development in a contemporary JIA inception cohort. Methods: Canadian children newly-diagnosed with JIA 2005–2010 had weight and height measurements every 6 months for 2 years, then yearly up to 5 years. These measurements were used to calculate mean age- and sex-standardized Z-scores, and estimate prevalence and cumulative incidence of growth impairments, and the impact of disease activity and corticosteroids on growth. Results: One thousand one hundred forty seven children were followed for median 35.5 months. Mean Z-scores, and the point prevalence of short stature (height  95th percentile, 15.8% to 16.4%) remained unchanged in the whole cohort. Thirty-three children (2.9%) developed new-onset short stature, while 27 (2.4%) developed tall stature (>97.5th percentile). Children with systemic arthritis (n = 77) had an estimated 3-year cumulative incidence of 9.3% (95%CI: 4.3–19.7) for new-onset short stature and 34.4% (23–49.4) for obesity. Most children (81.7%) received no systemic corticosteroids, but 1 mg/Kg/day prednisone-equivalent maintained for 6 months corresponded to a drop of 0.64 height Z-scores (0.56–0.82) and an increase of 0.74 BMI Z-scores (0.56–0.92). An increase of 1 in the 10-cm physician global assessment of disease activity maintained for 6 months corresponded to a drop of 0.01 height Z-scores (0–0.02). Conclusions: Most children in this modern JIA cohort grew and gained weight as children in the general population. About 1 in 10 children who had systemic arthritis, uncontrolled disease and/or prolonged corticosteroid use, had increased risk of growth impairment.Medicine, Faculty ofOther UBCNon UBCPediatrics, Department ofReviewedFacult