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

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.

Effect of exercise training on heath, quality of life, exercise capacity in juvenile idiopathic arthritis: a meta-analysis of randomized controlled trials

OBJECTIVE

Little is known about the efficacy and safety of exercise training on juvenile idiopathic arthritis (JIA). This study aims to investigate the effect of exercise on health, quality of life, and different exercise capacities in individuals with JIA.

METHOD

A comprehensive search of Medline, Embase, Web of Science, and the Cochrane Library was conducted from database inception to October, 2023. Included studies were randomized controlled trials (RCTs) reporting the effects of exercise on JIA patients. Two independent reviewers assessed the literature quality using the Cochrane Collaboration's risk of bias tool. Standardized mean differences (SMD) were combined using random or fixed effects models. The level of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULT

Five RCTs met the inclusion criteria, containing 216 female participants and 90 males. The meta-analysis results showed that exercise had no significant effect on JIA patients based on the Child Health Assessment Questionnaire (CHAQ) (SMD=-0.32, 95%CI: -0.83, 0.19; I2 = 73.2%, P = 0.011) and Quality of Life (QoL) (SMD = 0.27, 95%CI: -0.04, 0.58; I2 = 29.4%, P = 0.243) and no significant effect on peak oxygen uptake (VO2peak). However, exercise significantly reduced visual analog scale (VAS) pain scores in JIA patients (SMD = 0.50, 95%CI: -0.90, -0.10; I2 = 50.2%, P = 0.134). The quality of evidence assessed by GRADE was moderate to very low.

CONCLUSION

Exercise does not significantly affect the quality of life and exercise capacity in JIA patients but may relieve pain. More RCTs are needed in the future to explore the effects of exercise on JIA.

Bone erosions associated with systemic bone loss on HR-pQCT in women with longstanding polyarticular juvenile idiopathic arthritis

OBJECTIVES

To analyze longstanding polyarticular juvenile idiopathic arthritis (pJIA) for possible associations between localized bone damage (erosions), and systemic bone loss. Besides, to compare the systemic bone mass of pJIA with healthy controls.

METHODS

Thirty-four pJIA women and 99 healthy controls (HC) were included. Radius and tibia of all subjects were scanned by HR-pQCT. Volumetric bone mineral density (vBMD), bone microarchitecture, and -finite element parameters were analyzed. Patients underwent HR-pQCT of 2nd and 3rd metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the dominant hand, for bone erosions quantification.

RESULTS

The mean age of patients was 31.5 ± 7.4yrs with a mean disease duration of 21.7 ± 9.2yrs. Bone erosions were detectable in 79% of patients. The number of bone erosions was positively correlated with cortical porosity (Ct.Po) at tibia (r = 0.575, p = 0.001), and radius (r = 0.423, p = 0.018); and negatively correlated with cortical vBMD at tibia (r=-0.420, p = 0.015). In a logistic regression analysis, adjusted for anti-CCP, the presence of bone erosions was independently associated with Ct.Po at radius (p = 0.018) and cortical vBMD at tibia (p = 0.020). Moreover, cortical and trabecular vBMD, trabecular number, and μ-finite element parameters were decreased in patients compared to HC (p < 0.05).

CONCLUSION

Bone erosions in longstanding pJIA women were associated with decreased cortical bone parameters, and these patients showed systemic bone impairment at peripheral sites compared with healthy controls.

Juvenile idiopathic arthritis and its associated uveitis

INTRODUCTION

Juvenile idiopathic arthritis is the most common chronic rheumatologic disease in children. Uveitis is the most common extra-articular manifestation of JIA, and it can be a sight-threatening condition.

AREAS COVERED

In this review article, we discussed epidemiology, risk factors, clinical presentation, supportive laboratory tests, treatment options, and complications of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis associated uveitis. We covered conventional immunomodulatory therapy and biologic response modifiers agents for different types of Juvenile idiopathic arthritis and their associated uveitis. Finally, we discussed the course of disease, functional outcome, and the quality of life of Juvenile idiopathic arthritis and Juvenile idiopathic arthritis-associated uveitis.

EXPERT OPINION

Although clinical outcomes of Juvenile idiopathic arthritis and its associated uveitis have been improved over the past three decades by biologic response modifier agents, a significant proportion of patients require active treatment into adult life therefore screening and monitoring of these patients is required during the patient's entire life. The limited number of food and drug administration approved biologic response modifier agents for the treatment of Juvenile idiopathic arthritis associated uveitis justify more randomized clinical trials with new medications in this field.

Bone mineral density in egyptian children with juvenile idiopathic arthritis: possible correlation to serum RANKL / osteoprotegerin (OPG) ratio and OPG gene polymorphisms

BACKGROUND

Children with juvenile idiopathic arthritis (JIA) are at higher risk of decreased bone mineral density (BMD) compared with healthy children due to genetic, disease and medication-related causes. This study aims to investigate the possible effects of osteoprotegerin (OPG) gene polymorphisms and serum levels of osteoprotegerin (OPG) and receptor activator of nuclear factor κB-ligand (RANKL) and RANKL/OPG ratio on BMD in children with JIA.

METHODS

OPG gene rs2073617, rs3134069, serum RANKL, OPG and RANKL/OPG ratio were evaluated in 60 JIA children and 100 matched healthy controls. BMD was evaluated by lumbar dual energy X-ray absorptiometry (DEXA) according to which patients were classified in 2 groups (DEXA z-score above and below - 2). Composite disease activity was measured using the Juvenile Arthritis Disease Activity Score (JADAS) 27-joints. Articular damage was scored using the juvenile arthritis damage index (JADI).

RESULTS

Patients aged 12.05 ± 3.2 years, included 38 females and 31% had BMD z-score below-2. Systemic-onset JIA was the most frequent phenotype (38%). Genotypes and alleles frequencies of the 2 studied polymorphisms did not differ between patients and controls (p > 0.05 for all) while serum RANKL and RANKL/OPG ratio were significantly higher in patients compared to controls (p = < 0.001 and 0.03 respectively). Patients with BMD < -2 had significantly greater frequencies of rs2073617 TT genotype and T allele (p < 0.001), higher serum RANKL, RANKL/OPG ratio (p = 0.01, 0.002), female predominance (p = 0.02), higher articular and extra-articular damage index (p = 0.008,0.009) and more frequent steroid usage (p = 0.02) compared to patients with BMD z-score >-2. Multivariate analysis showed rs2073617 TT genotype, RANKL/OPG ratio, long disease duration (above 36 months) and use of steroid to be associated with decreased BMD (p = 0.03,0.04,0.01,0.01 respectively) in JIA children.

CONCLUSIONS

Egyptian children with JIA have decreased BMD. rs2073617 TT genotype and T allele, RANKL/OPG ratio are possible determinants of reduced BMD in JIA. Our results underline the importance of frequent monitoring of BMD in JIA children and trying to control disease activity to preserve long term bone health.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

Genetic Background and Molecular Mechanisms of Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in the paediatric population. JIA comprises a heterogeneous group of disorders with different onset patterns and clinical presentations with the only element in common being chronic joint inflammation. This review sought to evaluate the most relevant and up-to-date evidence on current knowledge regarding the pathogenesis of JIA subtypes to provide a better understanding of these disorders. Despite significant improvements over the past decade, the aetiology and molecular mechanisms of JIA remain unclear. It has been suggested that the immunopathogenesis is characterised by complex interactions between genetic background and environmental factors that may differ between JIA subtypes. Human leukocyte antigen (HLA) haplotypes and non-HLA genes play a crucial role in the abnormal activation of both innate and adaptive immune cells that cooperate in causing the inflammatory process. This results in the involvement of proinflammatory cytokines, including tumour necrosis factor (TNF)α, interleukin (IL)-1, IL-6, IL-10, IL-17, IL-21, IL-23, and others. These mediators, interacting with the surrounding tissue, cause cartilage stress and bone damage, including irreversible erosions. The purpose of this review is to provide a comprehensive overview of the genetic background and molecular mechanisms of JIA.

Evaluation of osteoporosis and related factors and quality of life of patients with juvenile idiopathic arthritis and burnout status of parents

Background/Aim: Juvenile idiopathic arthritis (JIA) can negatively influence the lives of children and parents. Because it is a chronic disease, a complete recovery is not expected; additionally, children with JIA and their parents must cope with problems such as chronic pain, physical disability, school absenteeism, and social communication disorders. Children’s quality of life (QoL) may be affected by all these problems. Also, prolonged exposure to stress and failure to cope with stress may cause burnout syndrome in parents. The study aims to evaluate osteoporosis, QoL of children with JIA and the burnout status of caregivers. Methods: In this prospective, cross-sectional study, 30 patients aged 4–18 years, who were followed up for at least 6 months with the diagnosis of JIA, were included. Demographic, clinical, and laboratory characteristics were recorded retrospectively. Daily dietary calcium intake and daily activity levels were questioned. The patients’ bone mineral densities (BMD) were measured by the Dual Energy X-ray Absorptiometry method. Z scores below -2 were classified as the osteoporosis group, and those above -2 were classified as the non-osteoporosis group. The Turkish Pediatric Quality of Life Inventory validated and reliable in Turkish children was used to evaluate the QoL. Maslach Burnout Inventory was used to evaluate the burnout status of parents. Results: The mean age of patients was 12.6 (4.3) years. Osteoporosis was detected in 46.7% (n=14) cases. The mean age was higher (14.5 [3.7] in the osteoporosis group and 10.9 [4.1] in the non-osteoporosis group) (P=0.032) and the rate of oligoarticular JIA (7.1%), daily calcium intake (288 [168-456] mg/kg), and duration of activity (3 [2-6] hours) were lower in the osteoporosis group (P=0.039, P=0.043, P<0.001, respectively). Among the QoL indicators, the physical health total score was the lowest. Emotional functionality scores decreased as the age increased (P=0.037) and increased as the BMD z-score increased (P=0.024). Emotional burnout, one of the parental burnout indicators, increased as the duration of illness increased (P=0.003), and the BMD z-score decreased (P=0.003). Depersonalization increased as the age increased (P=0.010) and the duration of the disease prolonged (P<0.001) and increased as daily activity duration (P=0.032) and BMD z-score values decreased (P=0.002). Personal achievement decreased as the age increased (P=0.025) and the duration of illness (P=0.014), and the time spent watching television increased (P=0.030). Emotional exhaustion and depersonalization of the parents increased as the scores in any of the indicators of QoL decreased (P<0.05 for each). The personal success of the parents increased as the scores in any of the indicators of QoL increased (P<0.05 for each). All QoL indicators, except for social functionality and psychosocial health total score, were significantly lower in the group with osteoporosis. In addition, parents of children with osteoporosis had higher emotional burnout and depersonalization scores and lowered personal achievement scores (P<0.05 for each). Conclusion: In the current study, we observed a decrease in the QoL of the children and burnout syndrome in the parents. It was found that the deterioration in children’s QoL indicators affected the burnout indicators of parents, and the presence of osteoporosis affected both QoL and parental burnout. Awareness of modifiable risk factors in children with JIA is very important. The disease and osteoporosis secondary to this disease can impair children's QoL and cause burnout in parents.

Drug Treatment of Low Bone Mass and Other Bone Conditions in Pediatric Patients

Osteoporosis may affect young individuals, albeit infrequently. In childhood, bone mass increases, reaching its peak between the second and third decades; then, after a period of stability, it gradually declines. Several conditions, including genetic disorders, chronic diseases, and some medications, can have an impact on bone homeostasis. Diagnosis in young patients is based on the criteria defined by the International Society for Clinical Densitometry (ISCD), published in 2013. High risk factors should be identified and monitored. Often simple interventions aimed to eliminate the underlying cause, to minimize the negative bone effects linked to drugs, or to increase calcium and vitamin D intake can protect bone mass. However, in selected cases, pharmacological treatment should be considered. Bisphosphonates remain the main therapeutic agent for children with significant skeletal fragility and are also useful in a large number of other bone conditions. Denosumab, an anti-RANKL antibody, could become a potential alternative treatment. Clinical trials to evaluate the long-term effects and safety of denosumab in children are ongoing.

It starts from the womb: maximizing bone health

The foundation of bone health is established in utero. Bone accrual starts from the developing fetus and continues throughout childhood and adolescence. This process is crucial to achieve peak bone mass. Understanding factors that influence bone accrual before attainment of peak bone mass is thus critical to improve bone health and prevent osteoporosis, thereby reducing the burden of osteoporotic fractures in older women. In this review, we broadly outline factors influencing peak bone mass from pregnancy to infancy, childhood and adolescence with potential diseases and medications that may affect the optimum trajectory to maximizing bone health. It is estimated that a 10% increase in peak bone mass will delay the onset of osteoporosis by 13 years in a woman.

Juvenile idiopathic arthritis: from aetiopathogenesis to therapeutic approaches

Juvenile idiopathic arthritis (JIA) is the most common paediatric rheumatological disorder and is classified by subtype according to International League of Associations for Rheumatology criteria. Depending on the number of joints affected, presence of extra-articular manifestations, systemic symptoms, serology and genetic factors, JIA is divided into oligoarticular, polyarticular, systemic, psoriatic, enthesitis-related and undifferentiated arthritis. This review provides an overview of advances in understanding of JIA pathogenesis focusing on aetiology, histopathology, immunological changes associated with disease activity, and best treatment options. Greater understanding of JIA as a collective of complex inflammatory diseases is discussed within the context of therapeutic interventions, including traditional non-biologic and up-to-date biologic disease-modifying anti-rheumatic drugs. Whilst the advent of advanced therapeutics has improved clinical outcomes, a considerable number of patients remain unresponsive to treatment, emphasising the need for further understanding of disease progression and remission to support stratification of patients to treatment pathways.

Update on the treatment of nonsystemic juvenile idiopathic arthritis including treatment-to-target: is (drug-free) inactive disease already possible?

PURPOSE OF REVIEW

This review concerns the outcome for nonsystemic juvenile idiopathic arthritis (JIA) with emphasis on treatment-to-target (T2T) and treatment strategies aiming at inactive disease by giving an overview of recent articles.

RECENT FINDINGS

More efficacious therapies and treatment strategies/T2T with inactive disease as target, have improved the outcome for JIA significantly. Recent studies regarding treatment strategies have shown 47-68% inactive disease after 1 year. Moreover, probability of attaining inactive disease at least once in the first year seems even higher in recent cohort-studies, reaching 80%, although these studies included relatively high numbers of oligoarticular JIA patients. However, 26-76% of patients flare upon therapy withdrawal and prediction of flares is still difficult.

SUMMARY

Remission can be achieved and sustained in (some) JIA patients, regardless of initial treatment. Cornerstone principles in the management of nonsystemic JIA treatment are early start of DMARD therapy, striving for inactive disease and T2T by close and repeated monitoring of disease activity. T2T and tight control appear to be more important than a specific drug in JIA. Next to inactive disease, it is important that patients/parents are involved in personal targets, like reduction of pain and fatigue. Future studies should focus on predictors (based on imaging-methods or biomarkers) for sustained drug-free remission and flare.

No radiographic wrist damage after treatment to target in recent-onset juvenile idiopathic arthritis

BACKGROUND

To evaluate radiographic progression of patients with new-onset juvenile idiopathic arthritis (JIA) in response to an early, tightly-controlled, treatment-to-target.

METHODS

Patients with JIA participating in the BeSt-for-Kids-study, randomized to 3 treatment strategy arms, were eligible if at least 1 conventional wrist-radiograph was available. Bone damage as reflected by carpal length was assessed using the Poznanski-score. The BoneXpert-method was used to determine the Bone Age (BA, > 5 years) and bone mineral density (BMD) of the wrist. These scores were evaluated over time and compared between the treatment arms and mean JADAS10-score using linear mixed models corrected for age and symptom duration.

RESULTS

In 60 patients, 252 radiographs were analysed. Baseline age and symptom duration were different between the arms. No difference in comparison to the healthy reference population was found at baseline for the Poznanski-score (IQR varying from - 0,82; 0.68), nor for BA (varying from - 0.88 to 0.74). Baseline BMD was statistically significantly lower in arm 3 (initial treatment with etanercept and methotrexate) (- 1.48; - 0.68) compared to arm 1 (- 0.84; - 0.04) and arm 2 (- 0.93; 0.15). After treatment to target inactive disease, the Poznanski-scores and the BA remained clinically unchanged, while the BMD in arm 3 improved (p < 0.05 vs arm 1).

CONCLUSIONS

Recent-onset JIA patients, treated-to-target aimed at inactive disease, showed no signs of radiographic wrist damage (Poznanski-score, BA or BMD) either at baseline or at follow-up, irrespective of treatment arm. A lower BMD at baseline in arm 3, initially treated with methotrexate and etanercept, improved significantly after treatment.

TRIAL REGISTRATION

NTR, NL1504 (NTR1574). Registered 01-06-2009.

[Fractures and bone mineral density in childhood]

BACKGROUND

In juvenile idiopathic arthritis and related chronic inflammatory diseases, proinflammatory cytokines inhibit bone formation and stimulate bone resorption. Anti-inflammatory drugs, such as glucocorticoids and nonsteroidal antirheumatic drugs (NSARD) have as a side effect the potential to inhibit growth and maintenance of bone. These issues are of particular importance for the growing skeleton in childhood and adolescence.

OBJECTIVE

This article presents a narrative overview about the dimension of the problem, a critical evaluation of diagnostic procedures and a discussion of available countermeasures.

METHODS

A systematic literature search was carried out and the available evidence was evaluated based on the authors' knowledge and clinical experience as experts in the field.

RESULTS AND CONCLUSION

In recent years solid data have been accumulated with respect to the interpretation of bone mineral density (BMD) measurements in children and adolescents. Based on these data from the literature and given that the radiation exposure is also very low, it is now possible to clinically apply BMD measurements in this population using dual energy X‑ray absorption (DXA) technology for risk evaluation and diagnosis, taking the respective phase of development and body length into consideration. Dynamic measurements over time appear to be especially valuable in the context of individual clinical data. Hence, BMD measurements can be helpful in monitoring bone health, especially in juvenile idiopathic arthritis and other related inflammatory diseases. Apart from the specific indications for extended diagnostics and bone targeted pharmacological treatment, this method can also contribute to the management of preventive measures, such as sufficient calcium and vitamin D intake and targeted exercise interventions. Even in times of extremely effective antirheumatic drugs, children with chronic inflammatory diseases still bear a risk for bone health.

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/.

Sex-, Ethnic-, and Age-Specific Centile Curves for pQCT- and HR-pQCT-Derived Measures of Bone Structure and Strength in Adolescents and Young Adults

There are presently no adolescent centile curves for bone parameters at the tibial midshaft using peripheral quantitative computed tomography (pQCT) or at the distal radius and tibia using high-resolution pQCT (HR-pQCT). Thus, we aimed to develop sex-, ethnic-, site-, and age-specific centile curves for pQCT and HR-pQCT-derived bone outcomes for youth and young adults aged 10 to 21 years. We acquired pQCT scans (XCT3000 or XCT2000) at the tibial midshaft (50% site) and HR-pQCT scans (XtremeCT) at the distal radius (7% site) and tibia (8% site) in a convenience sample of participants in the mixed-longitudinal University of British Columbia Healthy Bones III Study. We scanned 778 10- to 21-year-olds annually for a maximum of 11 years using pQCT (413 girls, 56% Asian; 365 boys, 54% Asian; n = 3160 observations) and 349 10- to 21-year-olds annually for a maximum of 4 years using HR-pQCT (189 girls, 51% Asian; 165 boys, 50% Asian; n = 1090 observations). For pQCT, we report cortical bone mineral density (BMD), total bone cross-sectional area, and polar strength-strain index. For HR-pQCT, we report standard measures (total BMD, trabecular number, thickness, and bone volume fraction) and automated segmentation measures (total bone cross-sectional area, cortical BMD, porosity, and thickness). We applied finite element analysis to estimate failure load. We applied the lamda, mu, sigma (LMS) method using LMS ChartMaker Light (version 2.5, The Institute of Child Health, London, UK) to construct LMS tables and centile plots. We report sex- and age-specific centiles (3rd, 10th, 25th, 50th, 75th, and 97th) for whites and Asians for pQCT bone parameters at the tibial midshaft and HR-pQCT bone parameters at the distal radius and tibia. These centile curves might be used by clinicians and scientists to interpret values or better understand trajectories of bone parameters in clinical populations, those from different geographic regions or of different ethnic origins. © 2018 American Society for Bone and Mineral Research.

Clinical utilities of quantitative ultrasound in osteoporosis associated with inflammatory rheumatic diseases

Secondary osteoporosis is an important co-morbidity related to inflammatory rheumatic diseases that is attributed to several factors including inflammatory cytokines, inactivity and glucocorticoid treatment. Quantitative ultrasound (QUS) has been utilized in osteoporosis research due to its detectability of bone density as well as bone quality. The current narrative review is to address the potential utilities of QUS in secondary osteoporosis of inflammatory rheumatic diseases, focusing on the clinical aspects of QUS in these diseases, based on the conformity of QUS with dual emission X-ray absorptiometry (DXA), the relationship with disease characteristics, and its capability of fracture prediction. Although limited data demonstrate that QUS had moderate to strong correlation with DXA, and might be useful as a potential imaging tool to screen for osteoporosis, further research is still required for QUS to be utilized effectively for the best outcome in these patients with rheumatic diseases.

Joint cartilage thickness and automated determination of bone age and bone health in juvenile idiopathic arthritis

BACKGROUND

BoneXpert is an automated method to calculate bone maturation and bone health index (BHI) in children with juvenile idiopathic arthritis (JIA). Cartilage thickness can also be seen as an indicator for bone health and arthritis damage. The objective of this study was to evaluate the relation between cartilage thickness, bone maturation and bone health in patients with JIA.

METHODS

Patients with JIA diagnosed according ILAR criteria included in a previous ultrasonography (US) study were eligible if hand radiographs were taken at the same time as the US examination. Of the 95 patients 67 met the inclusion criteria.

RESULTS

Decreased cartilage thickness was seen in 27% of the examined joints. Decreased BHI was seen in half of the JIA patient, and delayed bone maturation was seen in 33% of patients. A combination of decreased BHI and bone age was seen in 1 out of 5 JIA patients. Decreased cartilage thickness in the knee, wrist and MCP joint was negatively correlated with delayed bone maturation but not with bone health index.

CONCLUSION

Delayed bone maturation and decreased BHI were not related to a thinner cartilage, but a thicker cartilage. No relation with JADAS 10 was found. The rheumatologist should remain aware of delayed bone maturation and BHI in JIA patients with cartilage changes, even in the biologic era.

Protecting Bone Health in Pediatric Rheumatic Diseases: Pharmacological Considerations

Bone health in children with rheumatic conditions may be compromised due to several factors related to the inflammatory disease state, delayed puberty, altered life style, including decreased physical activities, sun avoidance, suboptimal calcium and vitamin D intake, and medical treatments, mainly glucocorticoids and possibly some disease-modifying anti-rheumatic drugs. Low bone density or even fragility fractures could be asymptomatic; therefore, children with diseases of high inflammatory load, such as systemic onset juvenile idiopathic arthritis, juvenile dermatomyositis, systemic lupus erythematosus, and those requiring chronic glucocorticoids may benefit from routine screening of bone health. Most commonly used assessment tools are laboratory testing including serum 25-OH-vitamin D measurement and bone mineral density measurement by a variety of methods, dual-energy X-ray absorptiometry as the most widely used. Early disease control, use of steroid-sparing medications such as disease-modifying anti-rheumatic drugs and biologics, supplemental vitamin D and calcium, and promotion of weight-bearing physical activities can help optimize bone health. Additional treatment options for osteoporosis such as bisphosphonates are still controversial in children with chronic rheumatic diseases, especially those with decreased bone density without fragility fractures. This article reviews common risk factors leading to compromised bone health in children with chronic rheumatic diseases and discusses the general approach to prevention and treatment of bone fragility.

Cross-sectional study shows that impaired bone mineral status and metabolism are found in nonmosaic triple X syndrome

AIM

The effect of a supernumerary X chromosome on bones has not been reported, and this study evaluated bone mineral status and metabolism in nonmosaic triple X syndrome.

METHODS

This cross-sectional study comprised 19 girls, with a median age of 10.9 years, with nonmosaic triple X syndrome and a control group matched for age and body size. We studied ionised and total calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase levels and urinary deoxypyridinoline concentrations. We also measured the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT) Z-scores.

RESULTS

Patients with nonmosaic triple X syndrome showed significantly reduced AD-SoS (p < 0.005) and BTT Z-scores (p < 0.0001) compared to the control group, and these results persisted when we divided the sample into prepubertal and pubertal patients (p < 0.05). These patients also had significantly reduced ionised calcium (p < 0.005) and 25(OH)D levels (p < 0.005) and higher phosphate (p < 0.0001) and PTH (p < 0.0001) levels.

CONCLUSION

Subjects with nonmosaic triple X syndrome exhibited a significant impairment in bone mineral status and metabolism similar to other X polisomy, such as Klinefelter's syndrome. This suggests the presence of a primary bone deficit and the need for regular and close monitoring of these subjects.

Bone Status in a Patient with Insulin-Like Growth Factor-1 Receptor Deletion Syndrome: Bone Quality and Structure Evaluation Using Dual-Energy X-Ray Absorptiometry, Peripheral Quantitative Computed Tomography, and Quantitative Ultrasonography

Haploinsufficiency of the insulin-like growth factor (IGF)-1 receptor (IGF1R) gene is a rare, probably under-diagnosed, cause of short stature. However, the effects of IGF1R haploinsufficiency on glucose metabolism, bone status, and metabolism have rarely been investigated. We report the case of a patient referred to our center at the age of 18 months for short stature, failure to thrive, and Silver-Russell-like phenotype. Genetic analysis did not show hypomethylation of the 11p15.5 region or uniparental disomy of chromosome 7. Growth hormone (GH) stimulation tests revealed GH deficiency, whereas IGF-1 was 248 ng/mL. r-hGH treatment showed only a slight improvement (from -4.4 to -3.5 SDS). At 10 years of age, the child was re-evaluated: CGH-array identified a heterozygous de novo 4.92 Mb deletion in 15q26.2, including the IGF1R gene. Dual-energy X-ray absorptiometry showed a normal bone mineral density z-score, while peripheral quantitative computed tomography revealed reduced cortical and increased trabecular elements. A phalangeal bone quantitative ultrasonography showed significantly reduced amplitude-dependent speed of sound and bone transmission time values. The changes in bone architecture, quality, and metabolism in heterozygous IGF1R deletion patients, support the hypothesis that IGF-1 can be a key factor in bone modeling and accrual.

Peripheral quantitative computed tomography (pQCT) for the assessment of bone strength in most of bone affecting conditions in developmental age: a review

Peripheral quantitative computed tomography provides an automatical scan analysis of trabecular and cortical bone compartments, calculating not only their bone mineral density (BMD), but also bone geometrical parameters, such as marrow and cortical Cross-Sectional Area (CSA), Cortical Thickness (CoTh), both periosteal and endosteal circumference, as well as biomechanical parameters like Cross-Sectional Moment of Inertia (CSMI), a measure of bending, polar moment of inertia, indicating bone strength in torsion, and Strength Strain Index (SSI). Also CSA of muscle and fat can be extracted. Muscles, which are thought to stimulate bones to adapt their geometry and mineral content, are determinant to preserve or increase bone strength; thus, pQCT provides an evaluation of the functional 'muscle-bone unit', defined as BMC/muscle CSA ratio. This functional approach to bone densitometry can establish if bone strength is normally adapted to the muscle force, and if muscle force is adequate for body size, providing more detailed insights to targeted strategies for the prevention and treatment of bone fragility. The present paper offers an extensive review of technical features of pQCT and its possible clinical application in the diagnostic of bone status as well as in the monitoring of the skeleton's health follow-up.

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.

Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome

Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7 ± 3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p < 0.005) and BTT (p < 0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p < 0.0001) and significantly lower 25(OH)D (p < 0.0001), osteocalcin (p < 0.05), and bone alkaline phosphatase levels (p < 0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages.

Comparison of bone mass and quality determinants in adolescents and young adults with juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA)

BACKGROUND

Few prospective data have been published on the comparison of bone density and quality in homogeneous groups of patients with juvenile systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA).

OBJECTIVE AND HYPOTHESIS

The objective of this study is to perform a longitudinal evaluation of the prevalence and the characteristics of bone mass and quality and to evaluate the differences on the bone parameters, using DXA, pQCT and QUS.

POPULATION AND/OR METHODS

Forty-three JSLE patients (35 females, 8 males, median age 18.8, range 14.0-34.1 years) have been studied with DXA, pQCT and QUS scans and compared with 138 JIA patients (112 females, 26 males, median age 18.9, range 13.4-33.2 years), and 79 controls (59 females, 20 males; median age 19.3, range 13.5-36.5 years). Of these, 39 patients (32 females and 7 males, median age 20.3, range 16.6-36.8 years) with JSLE were followed longitudinally and compared with 131 patients (108 females, 23 males median age 20.7, range 15.8-37.1 years) with JIA and 63 controls (48 females, 15 males; median age 21.9, range 15.5-38.3 years).

RESULTS

JSLE patients have a higher bone cortical density (CrtBMD) than controls and JIA patients (p < 0.005). However, JSLE and JIA patients have a significantly reduced bone trabecular density (TrbBMD) compared to controls (p < 0.0001), with no differences between JSLE and JIA. In addition, JIA patients show a significantly reduced muscle area (MuscleCSA) compared to JSLE and controls (p < 0.001). Conversely, fat area (FatCSA) is significantly increased both in JIA and JSLE patients when compared to controls (p < 0.001), with no differences between the JSLE and JIA groups. Analogous results are observed in the polar resistance to stress (SSIp). On longitudinal evaluation, contrary to CrtBMD, the difference between BMAD SDS, TrbBMD, MuscleCSA and FatCSA remains unchanged; in JSLE patients, SSIp is stable in comparison to JIA and controls without any difference between the two groups.

CONCLUSIONS

The evaluation of bone density and structure parameters in JSLE patients highlights significant differences compared with JIA patients and controls. These data might indicate a different pathogenesis of bone damage in the two entities, and suggest a different diagnostic and therapeutic approach to improve the peak bone mass.