Bone health and physical activity in adolescents with juvenile idiopathic arthritis: a cross-sectional case-control study

BACKGROUND

Adolescents with juvenile idiopathic arthritis (JIA) tend to engage in less physical activity than their typically developing peers. Physical activity is essential for bone development and reduced physical activity may detrimentally effect bone health. Thus, we examined differences in total body bone mineral content (BMC) and areal bone mineral density (aBMD) between adolescents with JIA and adolescent controls without JIA. We also examined associations between moderate-to-vigorous physical activity (MVPA), lean mass, and bone outcomes.

METHODS

Participants included 21 adolescents with JIA (14 females, 7 males) and 21 sex- and age-matched controls aged 10-20 years. Assessments included: height; weight; triple-single-leg-hop distance (TSLH); MVPA by accelerometry; and total body BMC, aBMD, and lean mass measured using dual X-ray absorptiometry. Height-adjusted z-scores were calculated for BMC and aBMD and used for all analyses. Multiple linear mixed effects models examined group differences in BMC and aBMD, adjusting for sex, maturity, MVPA, TSLH, and lean mass. Participants clusters, based on sex and age (within 18 months), were considered random effects.

RESULTS

Adolescents with JIA had lower total body aBMD z-scores [β (95% CI); -0.58 (-1.10 to -0.07), p = 0.03] and BMC z-scores [-0.47 (-0.91 to -0.03), p = 0.04] compared with controls. Mean daily MVPA was 22.0 min/day lower in adolescents with JIA than controls; however, MVPA was not associated with aBMD [-0.01 (-0.01 to 0.01), p = 0.32] or BMC [0.00 (-0.01 to 0.00), p = 0.39]. Lean mass was positively associated with aBMD [0.05 (0.01 to 0.09) g/cm2, p = 0.03] and BMC [0.06 (0.03 to 0.10) g, p < 0.001].

CONCLUSION

Adolescents with JIA had lower total body aBMD and BMC compared with sex- and age-matched controls without JIA. Group differences in bone outcomes were not associated with the lower MVPA participation of adolescents with JIA. Despite this, physical activity should still be encouraged as it promotes physical well-being.

Obesity as a comorbidity in children and adolescents with autoimmune rheumatic diseases

Childhood obesity is the public health issue with alarming rates recorded throughout developed world and an important modifiable health risk for developing various chronic diseases, with childhood-onset autoimmune rheumatic diseases among them also. The aim of this article was to summarize epidemiological, pathophysiological and clinical implication of obesity on juvenile idiopathic arthritis (JIA), childhood-onset systemic lupus erythematosus (cSLE), juvenile dermatomyositis (JDM), IgA vasculitis (IgAV) and Kawasaki disease (KD). We reviewed PubMed database and selected 74 relevant articles. Epidemiological data of obesity among children with autoimmune rheumatic diseases indicate an increased prevalence of it. Pathophysiological link between obesity, humoral adipokines and cytokines released from fat tissue and childhood-onset autoimmune rheumatic diseases is complex and still not entirely clear. From the clinical point of view, obesity was not associated with disease activity in JIA and cSLE, but proved to contribute on functional impairment in both diseases and affect poor treatment response in JIA patients. Early atherosclerosis and cardiovascular disease (CVD) development in obese children and adolescents with JIA, cSLE and JDM are certainly important obesity-related complications. Understanding how obesity affects children and adolescents with autoimmune rheumatic diseases may encourage clinicians to consider taking better preventive strategies in this population to improve their long-term outcome.

Bone Mineral Density and Serum 25OHD in Children and Adolescents With Juvenile Idiopathic Arthritis

Low bone mass is one of the complications of juvenile idiopathic arthritis (JIA). However, a study focusing on the low bone mass in children and adolescents with JIA in Southeast Asian countries is limited. This study aimed to evaluate the bone mineral density (BMD) of Thai patients with JIA and identify factors correlated with BMD. A cross-sectional study was conducted at a tertiary-care center. The BMD of the lumbar spines (BMDLS) and the total body (BMDTB) were measured by dual-energy X-ray absorptiometry. Thirty-eight patients were enrolled between July 2015 and January 2016. No patient had low BMDLS, and only 2 (5.3%) had low BMDTB. Serum 25-hydroxyvitamin D (25OHD) levels were significantly positively correlated with the BMDTB Z-score (coefficient: 0.047; 95% confidence interval = 0.011-0.082; P = .012). Our study demonstrated a very low prevalence of low bone mass. Optimization of the serum 25OHD level should be encouraged.

Parent Risk Perceptions, Physical Literacy, and Fundamental Movement Skills in Children With Juvenile Idiopathic Arthritis

PURPOSE

This pilot study sought to examine the fundamental movement skills (FMS) and physical literacy (PL) of children with juvenile idiopathic arthritis (JIA) and to explore their relationship with physical activity (PA) and parent perceptions of PA-related risks.

METHODS

Twenty-five children with JIA and their parents completed questionnaires. Fundamental movement skills were assessed in the laboratory and PA through accelerometry data.

RESULTS

Children spent a median of 39.4%, 40.9%, and 18.2% of their day sedentary, in light, and in moderate to vigorous PA, respectively. Fundamental movement skills and PL scores were within the average range, although were related to which joints (upper/lower body) were affected by JIA. Parents who viewed activities such as biking and climbing as risky tended to have children with weaker locomotor skills and lower PL.

CONCLUSION

Children with JIA had age-appropriate PA, FMS, and PL; however, parent perceptions of PA-related risks are related to their child's FMS and PL.

Vitamin D, oral health, and disease characteristics in juvenile idiopathic arthritis: a multicenter cross-sectional study

Background

Vitamin D deficiency has been associated with autoimmune diseases and oral health. Knowledge about the association between vitamin D status and oral conditions in JIA is limited. We aimed to investigate vitamin D status in a cohort of Norwegian children and adolescents with JIA and possible associations between serum vitamin D levels, clinical indicators of oral health, and JIA disease characteristics.

Methods

This multi-center, cross-sectional study, included individuals with JIA aged 4–16 years from three geographically spread regions in Norway. Demographic data, age at disease onset, disease duration, JIA category, disease status, medication, and vitamin D intake were registered. One blood sample per individual was analyzed for 25(OH) vitamin D, and the level of insufficiency was defined as < 50 nmol/L. A clinical oral examination was performed applying commonly used indices in epidemiological studies of dental caries, dental erosion, enamel defects, gingival bleeding, and oral hygiene. Serum vitamin D was used as exposure variable in multivariable regression analyses to estimate the associations between insufficient vitamin D level, JIA disease status, and oral conditions, with adjustments for age, sex, geographical region, BMI, seasonal blood sampling, and parental education.

Results

Among the 223 participants with JIA, 97.3% were Caucasians, 59.2% were girls, and median age was 12.6 years. Median disease duration was 4.6 years, and 44.4% had oligoarticular JIA. Mean serum vitamin D level was 61.4 nmol/L and 29.6% had insufficient levels. Vitamin D levels did not differ between sexes, but between regions, iso-BMI categories, age groups, and seasons for blood sampling. Insufficient vitamin D levels were associated with dentin caries (adjusted OR 2.89, 95% CI 1.43–5.86) and gingival bleeding (adjusted OR 2.36, 95% CI 1.10–5.01). No associations were found with active JIA disease or more severe disease characteristics.

Conclusion

In our study, nearly 30% had vitamin D insufficiency, with a particularly high prevalence among adolescents. Vitamin D insufficiency was associated with dentin caries and gingival bleeding, but not with JIA disease activity. These results point to the need for a multidisciplinary approach in the follow-up of children with JIA, including an increased focus on vitamin D status and oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02349-1.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

Body composition in longstanding juvenile dermatomyositis; Associations with disease activity, muscle strength and cardiometabolic measures

OBJECTIVE

To (i) compare body composition parameters in patients with longstanding juvenile dermatomyositis (JDM) and controls and (ii) explore associations between body composition and disease activity/inflammation, muscle strength, health-related quality of life (HRQL) and cardiometabolic measures.

METHODS

In a cross-sectional study, we included 59 patients (median disease duration 16.7 y; median age 21.5 y) and 59 age- and sex-matched controls. Active/inactive disease were defined by the PRINTO criteria. Body composition was assessed by total body dual-energy absorptiometry (DXA), inflammation by hs-CRP and cytokines, muscle strength by manual muscle test (MMT-8), HRQL by 36-item short form survey physical component score (SF-36 PCS) and cardiometabolic function by echocardiography (systolic and diastolic function) and serum-lipids.

RESULTS

DXA analyses revealed lower appendicular lean mass index (ALMI) (reflecting limb skeletal muscle mass), higher body fat percentage (BF%) and higher android: gynoid fat ratio (A: G ratio) (reflecting central fat distribution) in patients than controls, despite similar BMI. Patients with active disease had lower ALMI and higher BF% than those with inactive disease; lower ALMI and higher BF% were associated with inflammation (elevated monocyte attractant protein-1 (MCP-1) and hs-CRP). Lower ALMI was associated with reduced muscle strength; higher BF% was associated with impaired HRQL. Central fat distribution (higher A: G ratio) was associated with impaired cardiac function and unfavorable serum-lipids.

CONCLUSION

: Despite normal BMI, patients with JDM, especially those with active disease, had unfavorable body composition, which was associated with impaired HRQL/muscle strength and cardiometabolic function. The association between central fat distribution and cardiometabolic alterations is a novel finding in JDM.

Adiposity Is Related to Inflammatory Disease Activity in Juvenile Idiopathic Arthritis

OBJECTIVE

To identify factors associated with the higher proportion of fatty tissue and overweight/obesity observed in patients with juvenile idiopathic arthritis (JIA).

PATIENTS AND METHODS

We performed a cross-sectional study of 80 JIA patients aged 4-15 years with 80 age- and sex-matched healthy controls. Body composition was assessed using dual-energy x-ray absorptiometry. The 27-joint Juvenile Arthritis Disease Activity score (JADAS27) was calculated. Two multivariate models were constructed to identify factors associated with overweight/obesity and fat mass index (FMI).

RESULTS

No differences were found between cases and controls in body mass index (BMI) or body composition. However, compared with controls, patients with a high inflammatory activity (JADAS27 > 4.2 for oligoarticular JIA or >8.5 for polyarticular disease) had higher values for BMI (p = 0.006); total fat mass (p = 0.003); FMI (p = 0.001); and fat in the legs (p = 0.001), trunk (p = 0.001), and arms (p = 0.002). The factors associated with overweight/obesity in patients were the duration of therapy with biological drugs, measured in months (OR [95% CI] = 1.12 [1.02-1.04]; p = 0.037), and physical activity (OR [95% CI] = 0.214 [0.07-0.68]; p = 0.010), while the factors associated with FMI were age (β [95% CI] = 0.30 [0.17-1.41]; p = 0.014), JADAS27 (β [95% CI] = 0.45 [0.16-1.08]; p = 0.009), and physical activity (β [95% CI] = -0.22 [-5.76 to 0.29]; p = 0.031).

CONCLUSION

Our study revealed no differences between JIA patients with well-controlled disease and low disability and the healthy population in BMI or body composition. Furthermore, the association observed between inflammatory activity and adiposity could be responsible for poorer clinical course.

Growth and puberty in children with juvenile idiopathic arthritis

Juvenile Idiopathic Arthritis is one of the most prevalent chronic diseases in children, with an annual incidence of 2-20 cases per 100,000 and a prevalence of 16-150 per 100,000. It is associated with several complications that can cause short-term or long-term disability and reduce the quality of life. Among these, growth and pubertal disorders play an important role. Chronic inflammatory conditions are often associated with growth failure ranging from slight decrease in height velocity to severe forms of short stature. The prevalence of short stature in JIA varies from 10.4% in children with polyarticular disease to 41% of patients with the systemic form, while oligoarthritis is mostly associated with localized excessive bone growth of the affected limb, leading to limb dissymmetry. The pathogenesis of growth disorders is multifactorial and includes the role of chronic inflammation, long-term use of corticosteroids, undernutrition, altered body composition, delay of pubertal onset or slow pubertal progression. These factors can exert a systemic effect on the GH/IGF-1 axis and on the GnRH-gonadotropin-gonadic axis, or a local influence on the growth plate homeostasis and function. Although new therapeutic options are available to control inflammation, there are still 10-20% of patients with severe forms of the disease who show continuous growth impairment, ending in a short final stature. Moreover, delayed puberty is associated with a reduction in the peak bone mass with the possibility of concomitant or future bone fragility. Monitoring of puberty and bone health is essential for a complete health assessment of adolescents with JIA. In these patients, an assessment of the pubertal stage every 6 months from the age of 9 years is recommended. Also, linear growth should be always evaluated considering the patient's bone age. The impact of rhGH therapy in children with JIA is still unclear, but it has been shown that if rhGH is added at high dose in a low-inflammatory condition, post steroids and on biologic therapy, it is able to favor a prepubertal growth acceleration, comparable with the catch-up growth response in GH-deficient patients. Here we provide a comprehensive review of the pathogenesis of puberty and growth disorders in children with JIA, which can help the pediatrician to properly and timely assess the presence of growth and pubertal disorders in JIA patients.

Yoga and Aerobic Dance for Pain Management in Juvenile Idiopathic Arthritis: Protocol for a Pilot Randomized Controlled Trial

Background

Juvenile idiopathic arthritis (JIA) is one of the most common types of arthritis among children. According to JIA guidelines for physical activity (PA), structured PA interventions led to improved health outcomes. However, many PA programs, such as yoga and aerobic dance, have not been studied in this population despite being popular among youth. Web-based PA programs could provide patients with accessible and affordable interventions.

Objective

The primary aims of the proposed pilot randomized controlled trial (RCT) are to examine (1) the feasibility of conducting a full-scale RCT to evaluate the effectiveness of two popular types of PA: a yoga training program and an aerobic dance training program, in female adolescents (aged 13-18 years) with JIA compared with an electronic pamphlet control group; and (2) the acceptability of these interventions.

Methods

A three-arm prospective randomized open-label study with a parallel group design will be used. A total of 25 female adolescents with JIA who have pain will be randomized in a ratio of 2:2:1 to one of the 3 groups: (1) online yoga training program (group A: n=10); (2) online aerobic dance training program (group B: n=10); and (3) electronic pamphlet control group (group C: n=5). Participants in groups A and B will complete 3 individual 1-hour sessions per week using online exercise videos, as well as a 1-hour virtual group session per week using a videoconferencing platform for 12 weeks. Participants from all groups will have access to an electronic educational pamphlet on PA for arthritis developed by the Arthritis Society. All participants will also take part in weekly online consultations with a research coordinator and discussions on Facebook with participants from their own group. Feasibility (ie, recruitment rate, self-reported adherence to the interventions, dropout rates, and percentage of missing data), acceptability, and usability of Facebook and the videoconferencing platform will be assessed at the end of the program. Pain intensity, participation in general PA, morning stiffness, functional status, fatigue, self-efficacy, patient global assessment, disease activity, and adverse events will be assessed using self-administered electronic surveys at baseline and then weekly until the end of the 12-week program.

Results

This pilot RCT has been funded by the Arthritis Health Professions Association. This protocol was approved by the Children’s Hospital of Eastern Ontario Research Ethics Board (#17/08X). As of May 11, 2020, recruitment and data collection have not started.

Conclusions

To our knowledge, this is the first study to evaluate the effectiveness of yoga and aerobic dance as pain management interventions for female adolescents with JIA. The use of online programs to disseminate these 2 PA interventions may facilitate access to alternative methods of pain management. This study can lead to a full-scale RCT.

International Registered Report Identifier (IRRID)

PRR1-10.2196/12823

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.

Body composition in children with chronic inflammatory diseases: A systematic review

BACKGROUND & AIMS

Aberrations in body composition are expected in children suffering from chronic inflammatory conditions. The objective is to examine whether children with inflammatory bowel disease (IBD: Crohn's disease and ulcerative colitis), coeliac disease, asthma and juvenile idiopathic arthritis (JIA) have an altered body composition as compared to healthy children.

METHODS

A systematic review, registered in Prospero (registration number: CRD42018107645), was conducted according to PRISMA guidelines. We conducted a search of three databases, Pubmed, Cochrane and Scopus. An assessment of the quality of the study was performed.

RESULTS

Data from 50 studies, 32 with IBD, 8 with coeliac disease, 2 with asthma and 8 with JIA, involving 2399 children were selected for review after applying the eligibility criteria. In all but 4 studies, children with Crohn's disease exhibited decreased amounts of fat mass and fat free mass. Reductions in fat mass were also evident in studies in children with coeliac disease. It is uncertain whether body composition is altered in children with asthma or JIA.

CONCLUSIONS

Children with Crohn's disease manifest with lowered adiposity and lean mass and therefore are likely to be at risk for suffering malnutrition-related clinical complications. Apart from Crohn's disease, data examining body composition in children with chronic inflammatory conditions are scarce and there is a paucity of reports examining the relationship between inflammation and body composition. Interpretation of the current study results is hampered by the low quality of the studies and due to the fact that the analyses have been habitually secondary outcomes.

Dietary inflammatory index® and cortical bone outcomes in healthy adolescent children

Diet is thought to modulate inflammation. This study shows no relationships between the dietary inflammatory index (DII) and biomarkers of inflammation or bone after adjusting for covariates. Monocyte chemoattractant protein-1 was inversely associated with peripheral tibia cortical thickness and prospective childhood studies should be conducted to better understand this relationship and to determine if there are long-term consequences in adulthood.

INTRODUCTION

Examine the relationships between the DII-scores and bone and biomarkers of inflammation in 290 adolescents, ages 9-13 years.

METHODS

DII-scores were calculated from 3-day diet records and categorized into tertiles, low (< - 1.34), medium (- 1.34 to 1.41), and high (> 1.41) inflammation. Radius and tibia bone were assessed via peripheral quantitative computed tomography (Stratec XCT 2000) at the 66% site relative to the distal growth plate. Fasting serum was measured for tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and monocyte chemoattractant protein-1 (MCP-1). The relationships between DII-scores and bone and biomarkers of inflammation were assessed using bivariate and partial correlations adjusting for sexual maturation, sex, race, muscle cross-sectional area, and height. ANOVA/ANCOVA models were used to compare DII-tertiles with dependent variables.

RESULTS

DII-scores were negatively associated with tibia trabecular area (TtAr; r = - .141, P = .019), periosteal perimeter (PsPM; r = - .145, P = .016), endosteal perimeter (r = - .145, P = .016), strength strain index (SSI; r = - .129, P = .032), and radius TtAr (r = - .140, P = .020), PsPM (r = -.138, P = .027) and SSI (r = -.131, P = .036) but nullified when adjusting for covariates. Tibia PsPM was higher in the low DII group compared to the medium (P = .050) and high (P = .046) groups but nullified after controlling for covariates. DII-scores were not associated with TNF-α, VEGF, or IL-6, but were associated with MCP-1 only in the unadjusted model (r = .125, P = .042). In the adjusted model, MCP-1 was inversely associated with tibia cortical thickness (r = -.150 P = .030).

CONCLUSION

The DII-scores were not related to biomarkers of inflammation or bone; however, the biomarker of inflammation, MCP-1 was negatively associated with tibia CtTh. Future prospective pediatric studies should be conducted to better understand this relationship and determine if there are long-term implications in adulthood.

Slow speed resistance exercise training in children with polyarticular juvenile idiopathic arthritis

Background: Juvenile idiopathic arthritis (JIA) is an inflammatory autoimmune disease that can cause severe impairment and disability. Exercise is recommended to preserve joint mobility and function. Our objectives were to assess the safety, feasibility, and effects of slow speed resistance exercise in children with polyarticular JIA. Methods: Patients were recruited from a pediatric rheumatology clinic at an urban hospital and randomized to exercise or control groups. In the intervention group, slow speed resistance exercise with individualized instruction by a certified trainer was performed 1-2 times per week for 12 weeks. The control group performed home-based aerobic exercise 3 days per week for 12 weeks. Pre and post-body composition measurements by dual-energy X-ray absorptiometry; aerobic fitness by peak oxygen uptake during cycle ergometry; isometric muscle strength; and quality of life measures were obtained. Results: In the exercise group, 9/17 (53%) completed any exercise training. Of these nine subjects, five (55%) completed all 12 weeks of the protocol. In the control group, 8/16 (50%) reported compliance with the recommended aerobic exercise training at least one time per week. Only 2 subjects (12%) reported exercising more than once per week. There was no significant difference between pre- and post-measurements in any category in the exercise group. There was also significantly elevated body fat in both groups with only 17% in the control group and 23% in the exercise group meeting recommended <30% total body fat levels. Conclusions: Children with JIA participated safely in this resistance exercise protocol. The exercise was well-tolerated with no serious adverse events noted. While individual subjects reported improvement in fatigue and improved energy, there was no statistical difference in pre- and post-exercise measures of body composition or quality of life. Identifying ways to improve adherence and encourage exercise in children with JIA is important.

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/.

Growth of ovarian cancer xenografts causes loss of muscle and bone mass: a new model for the study of cancer cachexia

BACKGROUND

Cachexia frequently occurs in women with advanced ovarian cancer (OC), along with enhanced inflammation. Despite being responsible for one third of all cancer deaths, cachexia is generally under-studied in OC due to a limited number of pre-clinical animal models. We aimed to address this gap by characterizing the cachectic phenotype in a mouse model of OC.

METHODS

Nod SCID gamma mice (n = 6-10) were injected intraperitoneally with 1 × 107 ES-2 human OC cells to mimic disseminated abdominal disease. Muscle size and strength, as well as bone morphometry, were assessed. Tumour-derived effects on muscle fibres were investigated in C2C12 myotube cultures. IL-6 levels were detected in serum and ascites from tumour hosts, as well as in tumour sections.

RESULTS

In about 2 weeks, ES-2 cells developed abdominal tumours infiltrating omentum, mesentery, and adjacent organs. The ES-2 tumours caused severe cachexia with marked loss of body weight (-12%, P < 0.01) and ascites accumulation in the peritoneal cavity (4.7 ± 1.5 mL). Skeletal muscles appeared markedly smaller in the tumour-bearing mice (approximately -35%, P < 0.001). Muscle loss was accompanied by fibre atrophy, consistent with reduced muscle cross-sectional area (-34%, P < 0.01) and muscle weakness (-50%, P < 0.001). Body composition assessment by dual-energy X-ray absorptiometry revealed decreased bone mineral density (-8%, P < 0.01) and bone mineral content (-19%, P < 0.01), also consistent with reduced trabecular bone in both femurs and vertebrae, as suggested by micro-CT imaging of bone morphometry. In the ES-2 mouse model, cachexia was also associated with high tumour-derived IL-6 levels in plasma and ascites (26.3 and 279.6 pg/mL, respectively) and with elevated phospho-STAT3 (+274%, P < 0.001), reduced phospho-AKT (-44%, P < 0.001) and decreased mitochondrial proteins, as well as with increased protein ubiquitination (+42%, P < 0.001) and expression of ubiquitin ligases in the skeletal muscle of tumour hosts. Similarly, ES-2 conditioned medium directly induced fibre atrophy in C2C12 mouse myotubes (-16%, P < 0.001), consistent with elevated phospho-STAT3 (+1.4-fold, P < 0.001) and altered mitochondrial homoeostasis and metabolism, while inhibition of the IL-6/STAT3 signalling by means of INCB018424 was sufficient to restore the myotubes size.

CONCLUSIONS

Our results suggest that the development of ES-2 OC promotes muscle atrophy in both in vivo and in vitro conditions, accompanied by loss of bone mass, enhanced muscle protein catabolism, abnormal mitochondrial homoeostasis, and elevated IL-6 levels. Therefore, this represents an appropriate model for the study of OC cachexia. Our model will aid in identifying molecular mediators that could be effectively targeted in order to improve muscle wasting associated with OC.

Vitamin D and juvenile idiopathic arthritis

BACKGROUND

Vitamin D has been implicated in the pathogenesis of autoimmune diseases. While the roles of vitamin D in other autoimmune diseases have been investigated, less is known about the role of vitamin D in chronic childhood arthritis.

MAIN BODY

This review summarizes and evaluates evidence relating to 25-hydroxyvitamin D (25(OH)D) and chronic childhood arthritis. A scoping literature review was conducted using Ovid Medline, Ovid Embase, Cumulative Index to Nursing and Allied Health Literature, Web of Science and Scopus. Further, we geo-mapped the results of the studies to identify the patterns of the association between vitamin D and chronic childhood arthritis across the globe. Of 38 studies reporting 25(OH)D concentrations in childhood chronic arthritis, 32 (84.2%) reported that a significant number of children had suboptimal (< 75 nmol/L) status.

CONCLUSION

The data indicate suboptimal vitamin D status in children with chronic arthritis. Further, the association between low vitamin D and increased arthritis activity follow a north-south geographical gradient.

Adiposity in Juvenile Psoriatic Arthritis

OBJECTIVE

Adult patients with psoriatic arthritis are at increased risk for obesity and metabolic syndrome, but data regarding adiposity in children with juvenile psoriatic arthritis (JPsA) are limited. Our study assessed adiposity in children with JPsA in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

METHODS

Patients with JPsA in the CARRA registry were divided into nonoverweight and overweight groups using recommendations from the US Centers for Disease Control, and differences in demographic and clinical characteristics between groups at baseline and after 1-year followup were assessed using chi-square test, Fisher's exact test, T test, or Mann-Whitney U test, as appropriate. The prevalence of overweight status in the JPsA registry patients was compared to rheumatoid factor-positive and -negative polyarticular juvenile idiopathic arthritis (RF+polyJIA; RF-polyJIA) registry cohorts and the US pediatric population, using a chi-square goodness-of-fit test.

RESULTS

Overweight children represented 36.3% of this JPsA cohort (n = 320). Compared to nonoverweight children, they were significantly older at symptom onset and rheumatologist's first assessment, and scored significantly worse on patient/physician outcome measures. At 1-year followup, changes in body mass index were not associated with changes in clinical features or outcome measures. The prevalence of overweight and obesity in patients with JPsA was significantly higher than in RF+polyJIA patients, RF-polyJIA patients, and the US pediatric population.

CONCLUSION

In this registry, almost 1 in 5 patients with JPsA were obese and more than one-third were overweight. This is significantly more than expected compared to the US pediatric population, and appropriate longterm followup of this JPsA subgroup is warranted.

Factors Determining Bone Mineral Density in Patients with Biliary Atresia after a Successful Kasai Operation

BACKGROUND

Hepatic osteodystrophy is a common complication in patients with chronic liver disease, however, bone mineral status in patients with biliary atresia has rarely been investigated.

METHODS

Twenty-nine children with biliary atresia were enrolled in our study and their demographic data, bone mineral density (BMD) of lumbar spine and bilateral femoral neck, and biochemical parameters were measured and analyzed.

RESULTS

The majority of our patients had osteopenia or osteoporosis over at least one part of the skeleton although none had jaundice. Instead of T helper 1 cell cytokine, interleukin (IL)-4 had a significant negative correlation with BMD of the right femoral neck (β = -0.251, p = 0.027) and left femoral neck (β = -0.299, p = 0.012) independently by multiple linear regression analysis.

CONCLUSION

We conclude that chronic inflammation with increased expression of IL-4 may be an important factor for compromised bone health in patients with biliary atresia.

The impact of underlying disease on fracture risk and bone mineral density in children with rheumatic disorders: A review of current literature

Childhood rheumatic diseases are associated with negative impacts on the skeleton, related to both the underlying illness and complications of therapy. The effects of medications like corticosteroids are well recognized, leading to reductions in bone mineral density and bone strength and concomitant increases in bone fragility and fracture risk. The impact of factors directly attributable to the underlying disease is not as well recognized. In this article, we review relevant literature to identify data which can contribute to an understanding of the impact of childhood rheumatic disease on the skeleton. We conclude that childhood rheumatic diseases are associated with reductions in bone mineral density and increased risk of vertebral and non-vertebral fractures. These data are strongest for juvenile arthritis, while conclusions are more limited for other rheumatic illnesses, like juvenile systemic lupus erythematosus or juvenile dermatomyositis, due to small numbers of patients studied. Finally, we make recommendations for areas in need of further research. These include the need for long-term longitudinal studies and for data to be collected in patients who have not been treated with corticosteroids.

Assessment of the body composition and parameters of the cardiovascular risk in juvenile idiopathic arthritis

The study was aimed to evaluate cardiovascular risk parameters, body mass index (BMI) centiles for sex and age, and body fat percentage using the electric bioimpedance method in children with juvenile idiopathic arthritis (JIA). 30 children with JIA participated in the study. A control group included 20 children. Patients were well matched for the age and sex. The body mass and body fat percentage were determined using the segmental body composition analyser; the BMI centiles were determined. All patients had the following parameters determined: lipid profile, hsCRP, homocysteine, and IL-6. The intima media thickness (IMT) was measured. Patients with JIA had significantly lower body weight, BMI, and the BMI centile compared to the control group. The IL-6 levels were significantly higher in patients with JIA compared to the control group. There were no differences between two groups with regard to the lipid profile, % content of the fat tissue, homocysteine levels, hsCRP, and IMT. Further studies are necessary to search for reasons for lower BMI and BMI centile in children with JIA and to attempt to answer the question of whether lower BMI increases the cardiovascular risk in these patients, similarly as in patients with rheumatoid arthritis (RA).

Leisure in children and adolescents with juvenile idiopathic arthritis: a systematic review

The aim of this systematic review is to describe participation in social and physical leisure activities among children and adolescents with JIA, as well as identify potential determinants of leisure participation.

METHODS

Electronic databases were systematically searched for articles published up until June 2013 pertaining to participation in leisure activities among youth with JIA and other rheumatic diseases. Studies were included if they measured involvement in either social or physical leisure activities. Selection and quality appraisal of articles were completed independently by two authors.

RESULTS

Eight hundred and ninety-three articles were found through electronic and reference search. One hundred and nine full articles were reviewed to assess for eligibility. Twelve articles met inclusion criteria and findings were reviewed. Most focused on describing participation in physical rather than social activities. Results suggest that youth with JIA participated less in both social and physical leisure activities as compared to healthy peers, and those with JIA did not meet national recommendations for physical activity. Potential determinants of leisure participation were socio-demographic (age, sex), anthropometric (height, weight) and disease-related (JIA subtype, disease duration, pain, number of swollen or painful joints, stiffness, fatigue, well-being) factors.

CONCLUSION

Characterization of leisure activity remains limited and mostly focused on physical activity in JIA. Assessment of more comprehensive outcome measures is warranted to obtain a better description of leisure in this population. Evidence of the influence of contextual factors as potential determinants of involvement in leisure among children with pediatric rheumatologic diseases is needed.

High adiposity and serum leptin accompanied by altered bone turnover markers in severe juvenile idiopathic arthritis

OBJECTIVE

To evaluate interactions between skeleton and adipose tissue, and association of adipokines and bone turnover markers with disease-related factors in patients with severe juvenile idiopathic arthritis (JIA).

METHODS

Forty-nine patients (median age 14.8 yrs, median disease duration 10.2 yrs) with refractory polyarticular JIA and 89 sex-matched and age-matched healthy controls participated in the study. Study subjects underwent clinical examination, body composition assessment with dual-energy X-ray absorptiometry, and analyses for leptin, adiponectin, and bone turnover markers.

RESULTS

Patients with JIA were shorter and more often overweight (p = 0.001) or obese (p < 0.001) than controls. They had significantly higher serum leptin, even when adjusted for fat mass (p < 0.001), than did controls. Adiponectin did not differ between the groups. Concentration of carboxyterminal telopeptide of type I collagen was higher (p = 0.006) in patients. The inverse association between leptin and bone turnover markers disappeared in controls but was strengthened in patients when adjusted for fat mass. Leptin, adiponectin, or bone markers did not associate with variables of disease activity.

CONCLUSION

Patients with severe JIA had high adiposity accompanied by increased bone resorption. Their serum leptin was higher, even independently of fat mass. Leptin tended to associate inversely with bone turnover markers but did not associate with variables of disease activity.

Serum sclerostin in high-activity adult patients with juvenile idiopathic arthritis

Introduction

Juvenile idiopathic arthritis (JIA) is a disease associated with loss of bone mass, deterioration in bone mass quality and an increased risk of fractures. The objective of this study was to evaluate factors that predict bone mineral density (BMD) alterations in young adult patients with active JIA before and during therapy with tumour necrosis factor α (TNFα) inhibitors.

Methods

Thirty-one patients (twelve males and nineteen females; mean age =25.1 ± 6.1 years) with active JIA (mean Disease Activity Score in 28 joints (DAS28) =6.36 ± 0.64; mean high-sensitivity C-reactive protein (hsCRP) =18.36 ± 16.95 mg/L) were investigated. The control group consisted of 84 healthy individuals matched by sex and age. BMD, bone turnover markers and serum concentrations of soluble receptor activator of nuclear factor κB ligand, osteoprotegerin, dickkopf Wnt signalling pathway inhibitor 1 (Dkk1) and sclerostin were evaluated.

Results

Baseline BMD values in the lumbar spine, proximal femur, femoral neck and distal radius were significantly lower in patients with JIA compared to healthy control participants. Baseline sclerostin serum concentrations were significantly higher in patients with JIA compared to control participants. After 2 years of treatment with TNFα inhibitors, BMD was significantly increased in the lumbar spine. This increase correlated with a drop in DAS28 score. A statistically significant correlation between hsCRP and Dkk1 was found at baseline, as well as during the 2-year follow-up period. A significant reduction in serum sclerostin after 1 year of therapy was predictive of a drop in DAS28 score observed with a 1-year delay after reduction of serum sclerostin.

Conclusion

A significant correlation between the sclerostin serum concentration and the number of tender and swollen joints, but not BMD, supports the hypothesis that chondrocytes and cells of the subchondral bone may contribute to circulating sclerostin in JIA.

Bone mass and quality in patients with juvenile idiopathic arthritis: longitudinal evaluation of bone-mass determinants by using dual-energy x-ray absorptiometry, peripheral quantitative computed tomography, and quantitative ultrasonography

Introduction

Our objective was to evaluate longitudinally the main bone-mass and quality predictors in young juvenile idiopathic arthritis (JIA) patients by using lumbar spine dual-energy X-ray absorptiometry (DXA) scan, radius peripheral quantitative computed tomography (pQCT), and phalangeal quantitative ultrasonography (QUS) at the same time.

Methods

In total, 245 patients (172 females, 73 males; median age, 15.6 years: 148 oligoarticular, 55 polyarticular, 20 systemic, and 22 enthesitis-related-arthritis (ERA) onset) entered the study. Of these, 166 patients were evaluated longitudinally. Data were compared with two age- and sex-matched control groups.

Results

In comparison with controls, JIA patients, but not with ERA, had a reduced spine bone-mineral apparent density (BMAD) standard deviation score (P < 0.001) and musculoskeletal deficits, with significantly lower levels of trabecular bone mineral density (TrabBMD) (P < 0.0001), muscle cross-sectional area (CSA) (P < 0.005), and density-weighted polar section modulus (SSIp) (P < 0.05). In contrast, JIA showed fat CSA significantly higher than controls (P < 0.0001). Finally, JIA patients had a significant reduced amplitude-dependent speed of sound (AD-SoS) (P < 0.001), and QUS z score (P < 0.005).

Longitudinally, we did not find any difference in all JIA patients in comparison with baseline, except for the SSIp value that normalized. Analyzing the treatments, a significant negative correlation among spine BMAD values, TrabBMD, AD-SoS, and systemic and/or intraarticular corticosteroids, and a positive correlation among TNF-α-blocking agents and spine BMAD, TrabBMD, and AD-SoS were observed.

Conclusions

JIA patients have a low bone mass that, after a first increase due to the therapy, does not reach the normal condition over time. The pronounced bone deficits in JIA are greater than would be expected because of reduction in muscle cross-sectional area. Thus, bone alterations in JIA likely represent a mixed defect of bone accrual and lower muscle forces.

The association between lean mass and bone mineral content in the high disease activity group of adult patients with juvenile idiopathic arthritis

BACKGROUND

The study is aimed to evaluate body composition and bone status in adolescent and adult patients with active juvenile idiopathic arthritis (JIA) untreated with tumor necrosis factor alpha inhibitors.

METHODS

Adult patients (12 male and 19 female) with active JIA and 84 healthy age- and gender- matched controls were enrolled into the study. Body composition (tissue mass in grams, lean mass, fat mass and bone mineral content as a fraction of tissue mass) and areal bone mineral density parameters (aBMD) at the lumbar spine, proximal femur, femoral neck, distal radius and total body were assessed using dual energy x-ray absorptiometry (DXA), and correlated with clinical characteristics of the disease and physical performance tests. Disease activity was assessed using high-sensitivity C-reactive protein (hsCRP) and disease activity score 28 (DAS 28). Differences between the groups were tested by t-test, and One-way ANOVA. Correlations were assessed using the Pearson correlation coefficients and multiple linear regression analysis. Significances were counted at the 0.05 level.

RESULTS

In patients with clinically active JIA (DAS 28, 6.36 ± 0.64, hsCRP, 18.36 ± 16.95 mg/l), aBMD at all measured sites, bone mineral content (BMC) and lean mass were reduced, and fat mass was increased as compared with healthy controls. Significant negative correlations were observed between BMC and disease duration, use of glucocorticoids (GCs), and fat mass, respectively. A positive correlation was found between BMC and lean mass, and between the body fat fraction and the use of GCs. Using multiple linear regression analysis, lean mass was the only significant predictor of BMC of total body both in men and women, and of BMC of legs (only in men). Lean mass was also the only predicting factor of total proximal femur BMD and femoral neck BMD. No significant correlations have been determined among the body composition parameters and DAS 28 or hsCRP endpoints.

CONCLUSIONS

In adult patients with long-term active JIA, lean mass was the main determining factor of total body and leg BMC, and total proximal femur and femoral neck aBMD.

Effect of body composition on bone mineral density in Moroccan patients with juvenile idiopathic arthritis

Introduction

The link between bone mass and body composition is widely recognized, but only few works were selectively performed on subjects with juvenile idiopathic arthritis. The aim of our study was to investigate the effect of body composition on bone mineral density (BMD) in Moroccan patients with juvenile idiopathic arthritis.

Methods

Thirty three children with juvenile idiopathic arthritis (JIA) were included in a cross-sectional study. The diagnosis of JIA was made according to the criteria of the International League of Association of Rheumatology (ILAR). Body mass index (BMI) was calculated from the ratio of weight/height²(kg/m²). Pubertal status was determined according to the Tanner criteria. Bone status, body composition and bone mineral content (BMC) were analyzed by using dual-energy X-ray absorptiometry (DXA). BMD was assessed at the lumbar spine (L1-L4) and at total body in (g/cm²). Total body fat tissue mass (FTM) and lean tissue mass (LTM) were also analyzed by DXA and expressed in kilograms. In children, low BMD was defined as a Z-score less than -2 and osteoporosis was defined as a Z-score less than -2 with a fracture history.

Results

A cross-sectional study was conducted in 33 Moroccan patients with JIA aged between 4 and 16 years, Fat mass was not related to bone density; in contrast, BMD was positively associated to LTM in total body(r = =0.41, p= 0.04) but not in lumbar spine (r = 0.29, p= 0.17). There exist significant correlation between BMC and BMD in total body (r = 0.51, p = 0.01).

Conclusion

This study suggests that the LTM is a determining factor of the BMD during adolescence. Other studies with a broader sample would be useful to confirm this relation.

Measurement of bone mineral density by dual energy X-ray absorptiometry in juvenile idiopathic arthritis

OBJECTIVE

To evaluate bone mineral density using dual X-ray absorptiometry in Juvenile Idiopathic Arthritis (JIA) patients and factors affecting it, if any.

METHODS

A cross sectional study was conducted by enrolling thirty five patients of JIA and age and sex matched controls. Bone Mineral Density (BMD) and Z score of whole body, total body less head, lumbar spine and distal radius were obtained and adjusted for age, sex, weight and BMI in both cases and controls. Dietary intake of calcium, vitamin D intake, sunlight exposure, weight bearing physical activity, age of onset, duration of disease, disease activity score and treatment received (prednisolone and methotrexate) were recorded.

RESULTS

BMD was significantly lower among patients as compared to controls. Decreased dietary intake of vitamin D and calcium, decreased weight bearing physical activity and sunlight exposure were the major factors for low BMD. Use of steroid also decreased BMD to some extent, whereas use of methotrexate, disease duration and severity did not have a significant correlation with BMD.

CONCLUSIONS

Apart from disease control, it is important to improve the dietary intake of calcium, vitamin D and encourage more physical activities and exposure to sunlight in JIA patients.

An experimental therapy to improve skeletal growth and prevent bone loss in a mouse model overexpressing IL-6

Premature osteoporosis and stunted growth are common complications of childhood chronic inflammatory disease. Presently, no treatment regimens are available for these defects in juvenile diseases. We identified the sequential Fc-OPG/hPTH treatment as an experimental therapy that improves the skeletal growth and prevents the bone loss in a mouse model overexpressing IL-6.

INTRODUCTION

Premature osteoporosis and stunted growth are common complications of childhood chronic inflammatory diseases and have a significant impact on patients' quality of life. Presently, no treatment regimens are available for these defects in juvenile diseases. To test a new therapeutic approach, we used growing mice overexpressing the pro-inflammatory cytokine IL-6 (TG), which show a generalized bone loss and stunted growth.

METHODS

Since TG mice present increased bone resorption and impaired bone formation, we tested a combined therapy with the antiresorptive modified osteoprotegerin, Fc-OPG, and the anabolic PTH. We injected TG mice with Fc-OPG once at the 4th day of life and with hPTH(1-34) everyday from the 16th to the 30th day of age.

RESULTS

A complete prevention of growth and bone defects was observed in treated mice due to normalization of osteoclast and osteoblast parameters. Re-establishment of normal bone turnover was confirmed by RT-PCR analysis and by in vitro experiments that revealed the full rescue of osteoclast and osteoblast functions. The phenotypic recovery of TG mice was due to the sequential treatment, because TG mice treated with Fc-OPG or hPTH alone showed an increase of body weight, tibia length, and bone volume to intermediate levels between those observed in vehicle-treated WT and TG mice.

CONCLUSIONS

Our results identified the sequential Fc-OPG/hPTH treatment as an experimental therapy that improves the skeletal growth and prevents the bone loss in IL-6 overexpressing mice, thus providing the proof of principle for a therapeutic approach to correct these defects in juvenile inflammatory diseases.

Genetic polymorphisms of collagen type I α1 chain (COL1A1) gene increase the frequency of low bone mineral density in the subgroup of children with juvenile idiopathic arthritis

BACKGROUND

Collagen type I is one of the key proteins involved in the maturation, development and mineralization of bone. Genetic polymorphisms of collagen type I alpha-1 chain (COL1A1) gene are associated with low bone mineral density and higher risk of fractures in adults and children. We hypothesize that the polymorphic alleles and genotypes of COL1A1 gene influence bone mineralization and metabolism in children with juvenile idiopathic arthritis (JIA).

METHODS

We recruited 196 children with JIA in our study. Bone mineral density (BMD) was measured by lumbar spine dual-energy X-ray absorptiometry. Osteocalcin, Ca, Ca2+ and inorganic phosphate (Pi) were utilized for the assessment of bone metabolism. Molecular testing: Sp1 (rs1800012) and -1997G/T (rs1107946) polymorphisms of COL1A1 gene were detected RFLP.

RESULTS

No differences in genotype, allele and haplotype distribution of COL1A1 were detected among children with normal and low BMD (LBMD; <-2 standard deviation). The presence of GG genotype of Sp1 increased the incidence of LBMD in Tanner II to III children (odds ratio (OR) = 9.7 [95% confidence interval (CI), 1.2; 81.7], p = 0.02) as well as GG genotype of -1997G/T increased the frequency of LBMD in Tanner IV to V children (OR = 4.5 [95% CI, 0.9; 22.0], p = 0.048). Tanner I children with -1997GG genotype had lower Ca2+ and osteocalcin and higher Pi compared with carriers of -1997Т allele. Tanner IV to V children with -1997GG genotype had lower BMD and BMD-Z score than carriers of -1997Т.

CONCLUSIONS

The evaluation of the biologic effects of the GG Sp1 and GG of -1997G/T polymorphism of COL1A1 has shown negative effect on BMD and mineral turnover related to pubertal stage.

Early juvenile idiopathic arthritis

Early juvenile idiopathic arthritis (JIA) is important to recognize as timely diagnosis and treatment improves prognosis. It is a misconception that complications of JIA arise only from long-standing disease and that children will outgrow it. Early aggressive treatment is the paradigm as early disease activity has long-term consequences. There are predictors of persistent disease and joint erosions that may identify patients at higher risk. Control of disease activity within the first 6 months of onset confers improved clinical course and outcomes. The treatment perspective is thus one of early aggressive treatment for induction of disease control and ultimately remission.

Incident vertebral fractures among children with rheumatic disorders 12 months after glucocorticoid initiation: a national observational study

OBJECTIVE

To determine the frequency of incident vertebral fractures (IVF) 12 months after glucocorticoid (GC) initiation in children with rheumatic diseases and to identify children at higher risk.

METHODS

Children with rheumatic diseases initiating GC were enrolled in a prospective observational study. Annual spine radiographs were evaluated using the Genant semiquantitative method. Spine areal bone mineral density (aBMD) was measured every 6 months. Clinical features, including cumulative GC dose, back pain, disease and physical activity, calcium and vitamin D intake, and spine aBMD Z scores, were analyzed for association with IVF.

RESULTS

Seven (6%) of 118 children (95% confidence interval 2.9-11.7%) had IVF. Their diagnoses were: juvenile dermatomyositis (n = 2), systemic lupus erythematosus (n = 3), systemic vasculitis (n = 1), and mixed connective tissue disease (n = 1). One child was omitted from the analyses after 4 months because of osteoporosis treatment for symptomatic IVF. Children with IVF received on average 50% more GC than those without (P = 0.030), had a greater increase in body mass index (BMI) at 6 months (P = 0.010), and had greater decrements in spine aBMD Z scores in the first 6 months (P = 0.048). Four (67%) of 6 children with IVF and data to 12 months had spine aBMD Z scores less than -2.0 at 12 months compared to 16% of children without IVF (P = 0.011).

CONCLUSION

The incidence of VF 12 months following GC initiation was 6%; most children were asymptomatic. Children with IVF received more GC, had greater increases in BMI, and had greater declines in spine aBMD Z scores in the first 6 months.

Bone health in children and adolescents with juvenile idiopathic arthritis and the influence of short-term physical exercise

PURPOSE

To study bone mineral density (BMD) in 54 children and adolescents with juvenile idiopathic arthritis before and after a short-term exercise program.

METHODS

Fifty-four children, 41 girls and 13 boys, median age 13.9 years, participated in a 12-week exercise program, with 33 children in an exercise group. The program consisted of one hundred 2-footed jumps with a rope and standardized muscle strength exercise. Both BMD and bone mineral content were assessed with dual-energy x-ray absorptiometry (DXA) and DXA Laser Calscan for the heel at the start and after 3 and 6 months.

RESULTS

The study group had BMD measurements within the reference range compared with normative data with Z score at start. Bone mineral density values in total body, but not Z score, increased significantly (P = .012) in the exercise group.

CONCLUSIONS

The study group had BMD measurements within the reference range. Twelve weeks of exercise increases BMD in children with juvenile idiopathic arthritis.

Cephalometric evaluation of children with familial Mediterranean fever

OBJECTIVE

To test the null hypothesis that no differences exist in craniofacial morphology between patients with familial Mediterranean fever (FMF) and the healthy population.

MATERIALS AND METHODS

Standardized lateral cephalograms of 32 FMF patients (mean age, 11.50 ± 2.72 years) and 32 healthy controls (mean age, 11.86 ± 2.19 years) were obtained. Cranial and dentofacial parameters were measured using a cephalometric analysis program (Nemoceph Imaging Cephalometric and Tracing Software S.L., Spain). All statistical analyses were conducted using SPSS version 17.0.0 (SPSS Inc., Chicago, Ill). Descriptive statistics were calculated for all measurements, and the independent t-test was used to evaluate intergroup differences.

RESULTS

The ANB angle was significantly greater in the FMF group (P < .05). Differences in SNA and SNB angles were insignificant. Anterior (P < .001) and posterior (P < .05) face heights were significantly shorter in the FMF group. Mandibular body length (P < .001) and condylion to gnathion (P < .05) measurements were significantly shorter in the FMF group. The upper lip was more protrusive in the FMF group (P < .05). U1-NA (mm; P < .001) and L1-NB (mm; P < .05) measurements were significantly shorter in the FMF group.

CONCLUSION

The hypothesis is rejected. Significant differences exist between the craniofacial morphology of patients with FMF and the healthy population.

Bone health in adult men and women with a history of juvenile idiopathic arthritis

OBJECTIVE

Our aim was to determine areal bone mineral density (BMD(a)) and disease-related factors linked with BMD(a) in adults with a history of juvenile idiopathic arthritis (JIA).

METHODS

Men and women with a history of JIA attending a young adult rheumatology clinic in Newcastle, UK, underwent dual energy x-ray absorptiometry (DEXA) of the lumbar spine and total hip. Information was obtained about disease duration and subtype, previous treatment including corticosteroid and methotrexate therapy, and large-joint replacement. Subjects completed the modified Health Assessment Questionnaire (HAQ). Blood was taken for assessment of C-reactive protein, erythrocyte sedimentation rate, and rheumatoid factor (RF).

RESULTS

Seventy-one women and 16 men, mean age 28.7 and 31.4 years, and mean disease duration 20.6 and 24.0 years, respectively, were studied. Mean BMD(a) was 0.982 (Z-score = -0.328; 95% CI -0.657, 0.001) and 1.028 g/cm(2) (Z-score = -0.251; 95% CI -1.266, 0.764) in women and men, respectively, at the spine and 0.817 (Z-score = -0.542; 95% CI -0.975, -0.109) and 0.857 g/cm(2) (Z-score = -0.176; 95% CI -2.323, 1.971) at the hip. After adjusting for age and sex, increasing HAQ score was associated with both lower spine BMD(a) and hip BMD(a). Compared with patients with oligoarticular disease, those with enthesitis-related arthritis had higher BMD(a) at the spine, while those with extended oligoarticular and polyarticular RF-negative disease had lower hip BMD(a). Oral corticosteroids and the presence of a large-joint replacement were associated with lower BMD(a) at both the spine and hip.

CONCLUSION

There was a trend toward low BMD(a) in women with a history of JIA. These patients may be at risk of the complications of osteoporosis including fragility fractures and should be considered for targeted preventive measures.

Secondary osteoporosis in patients with juvenile idiopathic arthritis

Bone disease in patients with juvenile idiopathic arthritis (JIA) is associated with focal (joint erosion and juxtaarticular osteopenia) and systemic bone loss (generalized osteopenia or reduction of bone mass density). Pathophysiology of bone loss is multifactorial and involves particularly proinflammatory cytokines and deleterious effects of glucocorticoid therapy. Clinical studies in patients with JIA indicate excessive activation of osteoclastogenesis and reduction of bone formation. Reduction of physical activity, muscle atrophy caused by high disease activity, and compulsory restriction in movements are also associated with bone loss. In patients with JIA, the disease can be complicated by growth cartilage involvement and systemic or local growth retardation. In the absence of preventive measures, fragility fractures can occur even at an early age.

Serum levels of osteoprotegerin and receptor activator of nuclear factor -κB ligand in children with early juvenile idiopathic arthritis: a 2-year prospective controlled study

BACKGROUND

The clinical relevance of observations of serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor -κB ligand (RANKL) in juvenile idiopathic arthritis (JIA) is not clear. To elucidate the potential role of OPG and RANKL in JIA we determined serum levels of OPG and RANKL in patients with early JIA compared to healthy children, and prospectively explored changes in relation to radiographic score, bone and lean mass, severity of the disease, and treatment.

METHODS

Ninety children with early oligoarticular or polyarticular JIA (ages 6-18 years; mean disease duration 19.4 months) and 90 healthy children individually matched for age, sex, race, and county of residence, were examined at baseline and 2-year follow-up. OPG and RANKL were quantified by enzyme-immunoassay. Data were analyzed with the use of t-tests, ANOVA, and multiple regression analyses.

RESULTS

Serum OPG was significantly lower in patients than controls at baseline, and there was a trend towards higher RANKL and a lower OPG/RANKL ratio. Patients with polyarthritis had significantly higher increments in RANKL from baseline to follow-up, compared to patients with oligoarthritis. RANKL was a significant negative predictor for increments in total body lean mass. Patients who were receiving corticosteroids (CS) or disease-modifying antirheumatic drugs (DMARDs) at follow-up had higher OPG/RANKL ratio compared with patients who did not receive this medication.

CONCLUSIONS

The data supports that levels of OPG are lower in patients with JIA compared to healthy children, and higher levels of RANKL is associated with more serious disease. RANKL was a significant negative predictor of lean mass in patients with JIA. The OPG/RANKL ratio was higher in patients on DMARDs or CS treatment.

Cross-sectional and Longitudinal Evaluation of Bone Mass in Children and Young Adults with Juvenile Idiopathic Arthritis: The Role of Bone Mass Determinants in a Large Cohort of Patients

Objective.

To assess the prevalence of reduced spine bone mineral apparent density (BMAD), and to identify the main predictors of reduced spine BMAD in a cross-sectional and longitudinal evaluation of the same large cohort of patients with juvenile idiopathic arthritis (JIA). There are few prospective data on bone mass evaluation in a large number of patients with JIA, and with enthesitis-related arthritis onset.

Methods.

Two hundred nineteen patients with JIA (median age 8.7 yrs, range 6.1–13.1 yrs; 104 oligoarticular JIA, 61 polyarticular, 20 systemic, and 34 enthesitis-related arthritis onset) were retrospectively evaluated. A dual-energy x-ray absorptiometry (DEXA) scan at the lumbar spine was performed in all subjects. Of these, 89 consecutive patients were followed up randomly and longitudinally with a second and a third DEXA evaluation. The data obtained were compared with 80 age-matched and sex-matched healthy subjects.

Results.

At the first DEXA, patients with JIA showed a reduced spine BMAD standard deviation score (SDS) in comparison to controls (p < 0.001). These results were confirmed when the subjects were divided into JIA subtypes (p < 0.005) with the exception of enthesitis-related arthritis onset. Spine BMAD SDS significantly correlated with JIA onset type (p < 0.01), age at JIA onset (p < 0.005), and flares (p = 0.008). The longitudinal evaluation showed that spine BMAD SDS did not significantly improve at the followup in comparison to controls, in all subsets with JIA except for systemic onset (p < 0.05). Spine BMAD correlated with sex (p < 0.01), systemic corticosteroid exposure (p < 0.01), the number of intraarticular corticosteroid injections (p < 0.01), the interval from last steroid injection (p < 0.05), erythrocyte sedimentation rate (p < 0.005), and C-reactive protein levels (p < 0.005).

Conclusion.

Patients with JIA have a low bone mass and, after a first increase due to therapy, do not reach a healthy condition over time despite our current more effective drugs. These patients have a high risk of osteoporosis in early adulthood. To reduce the risk and improve the bone mass, close monitoring of bone mineral density, better control of disease activity, physical activity, and intake of calcium and vitamin D are recommended. In patients with osteoporosis, therapeutic approaches including bisphosphonates should be considered.

Prevalent vertebral fractures among children initiating glucocorticoid therapy for the treatment of rheumatic disorders

OBJECTIVE

Vertebral fractures are an under-recognized problem in children with inflammatory disorders. We studied spine health among 134 children (87 girls) with rheumatic conditions (median age 10 years) within 30 days of initiating glucocorticoid therapy.

METHODS

Children were categorized as follows: juvenile dermatomyositis (n = 30), juvenile idiopathic arthritis (n = 28), systemic lupus erythematosus and related conditions (n = 26), systemic arthritis (n = 22), systemic vasculitis (n = 16), and other conditions (n = 12). Thoracolumbar spine radiograph and dual x-ray absorptiometry for lumbar spine (L-spine) areal bone mineral density (BMD) were performed within 30 days of glucocorticoid initiation. Genant semiquantitative grading was used for vertebral morphometry. Second metacarpal morphometry was carried out on a hand radiograph. Clinical factors including disease and physical activity, calcium and vitamin D intake, cumulative glucocorticoid dose, underlying diagnosis, L-spine BMD Z score, and back pain were analyzed for association with vertebral fracture.

RESULTS

Thirteen vertebral fractures were noted in 9 children (7%). Of these, 6 patients had a single vertebral fracture and 3 had 2-3 fractures. Fractures were clustered in the mid-thoracic region (69%). Three vertebral fractures (23%) were moderate (grade 2); the others were mild (grade 1). For the entire cohort, mean +/- SD L-spine BMD Z score was significantly different from zero (-0.55 +/- 1.2, P < 0.001) despite a mean height Z score that was similar to the healthy average (0.02 +/- 1.0, P = 0.825). Back pain was highly associated with increased odds for fracture (odds ratio 10.6 [95% confidence interval 2.1-53.8], P = 0.004).

CONCLUSION

In pediatric rheumatic conditions, vertebral fractures can be present prior to prolonged glucocorticoid exposure.