Assessment of bone mineral density in adults with a history of juvenile chronic arthritis: a cross-sectional long-term followup study

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.

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.

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.

Dynamic knee joint function in children with juvenile idiopathic arthritis (JIA)

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a chronic illness with a high risk of developing long-term disability. Disease activity is currently being monitored and quantified by ACR core set. Here, joint inflammation is determined; however joint function is the crucial component for developing disability. The aim of this study was to quantify and compare dynamic joint function in healthy and arthritic knee joints and to evaluate response to improvement.

METHODS

A single center cohort study of consecutive children presenting to the rheumatology outpatient clinic was performed to measure dynamic knee joint function. Serial measures were performed if possible. Splint fixed electrogoniometers were used to measure dynamic knee joint function including ROM and flexion and extension torque.

RESULTS

A total of 54 children were tested including 44 with JIA, of whom eight had to be excluded for non-JIA-related knee problems. The study included 36 JIA patients of whom eight had strictly unilateral knee arthritis, and nine controls. Dynamic joint function ROM and torque depended on age and bodyweight, as demonstrated in healthy joints. ROM and torques were significant lower in arthritic compared to unaffected knee joints in children with unilateral arthritis and across the cohort. Importantly, extension torque was the most sensitive marker of impaired joint function. Follow up measurements detected responsiveness to change in disease activity.

CONCLUSIONS

Measuring dynamic joint function with electrogoniometers is feasible and objective. Active ROM and torque during flexion and extension of arthritic knee joints were significant lower compared to unaffected. In dynamic joint measurement extension torque is a sensitive marker for disease activity.

Assessment and management of pain in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in childhood. Persistent pain is the most common and distressing symptom of JIA, and pain in childhood arthritis is multifactorial. Children and adolescents with persistent pain due to JIA experience significantly more problems with physical, emotional, social, and school functioning than healthy individuals. Assessment of pain at each office visit is the cornerstone of effective pain management and should include an evaluation of pain intensity, interference, and coping. Following the biopsychosocial model of pain management, a multi-modal approach is recommended for pain control in children with arthritis. Pharmacologic strategies for the treatment of pain in JIA include aggressive treatment of the underlying disease as well as the use of acetaminophen and systemic and topical non-steroidal anti-inflammatory drugs for persistent mild pain. Opioids can be considered in the case of moderate to severe persistent pain. Physical therapies and psychological interventions such as cognitive behavioral therapy are also key components of pain management in JIA.

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.

What does an adult rheumatologist need to know about juvenile idiopathic arthritis?

JIA is the most common chronic inflammatory arthritis in children and young people and an estimated one-third of individuals will have persistent active disease into adulthood. There are a number of key differences in the clinical manifestations, assessment and management of JIA compared with adult-onset arthritis. Transition and transfer to adult services present significant challenges for many patients, their families and health care professionals. We describe key clinical issues relevant to adult rheumatology health care teams responsible for ongoing care of these young people.

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.

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.

A review of the use of dual-energy X-ray absorptiometry (DXA) in rheumatology

The principal use of dual-energy X-ray absorptiometry (DXA) is to diagnose and monitor osteoporosis and therefore reduce fracture risk, associated morbidity, and mortality. In the field of rheumatology, DXA is an essential component of patient care because of both rheumatologists’ prescription of glucocorticoid treatment as well as the effects of rheumatological diseases on bone health. This review will summarize the use of DXA in the field of rheumatology, including the concern for glucocorticoid-induced osteoporosis, as well as the association of osteoporosis with a sampling of such rheumatologic conditions as rheumatoid arthritis (RA), systemic lupus erythematosus, ankylosing spondylitis, juvenile idiopathic arthritis, and scleroderma or systemic sclerosis. Medicare guidelines recognize the need to perform DXA studies in patients treated with glucocorticoids, and the World Health Organization FRAX tool uses data from DXA as well as the independent risk factors of RA and glucocorticoid use to predict fracture risk. However, patient access to DXA measurement in the US is in jeopardy as a result of reimbursement restrictions. DXA technology can simultaneously be used to discover vertebral fractures with vertebral fracture assessment and provide patients with a rapid, convenient, and low-radiation opportunity to clarify future fracture and comorbidity risks. An emerging use of DXA technology is the analysis of body composition of RA patients and thus the recognition of “rheumatoid cachexia,” in which patients are noted to have a worse prognosis even when the RA appears well controlled. Therefore, the use of DXA in rheumatology is an important tool for detecting osteoporosis, reducing fracture risk and unfavorable outcomes in rheumatological conditions. The widespread use of glucocorticoids and the underlying inflammatory conditions create a need for assessment with DXA. There are complications of conditions found in rheumatology that could be prevented with more widespread patient access to DXA.

Adding to complexity: comorbidity in paediatric rheumatic disease

Novel therapies including biologic agents offer paediatric rheumatologists significant opportunity to improve long-term prognosis for children with rheumatic disease. However, comorbidities related to the diseases themselves and their treatments pose specific challenges to be overcome. Prompt recognition and appropriate management will improve quality of life, effectiveness of treatment and overall prognosis. In this review, we discuss key areas of comorbidity frequently encountered in paediatric rheumatology including cardiovascular, renal, genito-urinary and visual comorbidity, bone health, drug-related issues and the influence of rheumatic disease on growth and puberty.

Trial of early aggressive therapy in polyarticular juvenile idiopathic arthritis

OBJECTIVE

To determine whether aggressive treatment initiated early in the course of rheumatoid factor (RF)-positive or RF-negative polyarticular juvenile idiopathic arthritis (JIA) can induce clinical inactive disease within 6 months.

METHODS

Between May 2007 and October 2010, a multicenter, prospective, randomized, double-blind, placebo-controlled trial of 2 aggressive treatments was conducted in 85 children ages 2-16 years with polyarticular JIA of <12 months' duration. Patients received either methotrexate (MTX) 0.5 mg/kg/week (maximum 40 mg) subcutaneously, etanercept 0.8 mg/kg/week (maximum 50 mg), and prednisolone 0.5 mg/kg/day (maximum 60 mg) tapered to 0 by 17 weeks (arm 1), or MTX (same dosage as arm 1), etanercept placebo, and prednisolone placebo (arm 2). The primary outcome measure was clinical inactive disease at 6 months. An exploratory phase determined the rate of clinical remission on medication (6 months of continuous clinical inactive disease) at 12 months.

RESULTS

By 6 months, clinical inactive disease had been achieved in 17 (40%) of 42 patients in arm 1 and 10 (23%) of 43 patients in arm 2 (χ(2) = 2.91, P = 0.088). After 12 months, clinical remission on medication was achieved in 9 patients in arm 1 and 3 patients in arm 2 (P = 0.053). There were no significant interarm differences in adverse events.

CONCLUSION

Although this study did not meet its primary end point, early aggressive therapy in this cohort of children with recent-onset polyarticular JIA resulted in clinical inactive disease by 6 months and clinical remission on medication within 12 months of treatment in substantial proportions of patients in both arms.

Prevalence of vertebral compression fractures and associated factors in children and adolescents with severe juvenile idiopathic arthritis

OBJECTIVE

Vertebral fractures occur in patients with juvenile idiopathic arthritis (JIA), but data on their frequency and causes are scarce. Our cross-sectional study evaluated prevalence of compression fractures and associated factors in a high-risk pediatric population with severe JIA.

METHODS

Children and adolescents with a history of treatment-resistant polyarticular-course JIA for ≥ 5 years or systemic arthritis for ≥ 3 years were recruited. Clinical examination, dietary recall, laboratory measurements, bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry, and spinal radiography were performed.

RESULTS

Our study included 50 patients (41 girls), of whom 6 (12%) had systemic arthritis, with a median age of 14.8 years (range 7.0-18.7 yrs) and median disease duration of 10.2 years (range 3.9-16.8 years). Ninety-four percent had used systemic glucocorticoids (GC); the median total duration of GC treatment was 7.1 years (range 0-15.5 yrs). The median weight-adjusted cumulative GC dose for the preceding 3 years was 72 mg/kg (range 0-911 mg/kg). The median bone age-corrected lumbar spine and whole-body areal BMD Z-scores were -0.8 and -1.0, respectively. Twenty-two percent had vertebral fractures, mostly thoracic. Compression fractures were associated with high disease activity, high body mass index (BMI), and high recent cumulative GC dose, but not with disease duration or BMD. Thirty percent had sustained at least 1 peripheral low energy fracture. Twenty-six percent were deemed to have significantly compromised bone health.

CONCLUSION

Severe JIA is associated with a significant risk of vertebral compression fractures. Associated factors include high disease activity, high BMI, and high recent GC exposure. Further studies are needed to establish optimal prevention and treatment guidelines.

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.

Biochemical markers of bone turnover associated with calcium supplementation in children with juvenile rheumatoid arthritis: results of a double-blind, placebo-controlled intervention trial

OBJECTIVE

To determine the effects of calcium supplementation on bone physiology in corticosteroid-free children with juvenile rheumatoid arthritis (JRA) by measuring serum and urinary bone-related hormones, minerals, and markers of bone formation and resorption.

METHODS

In this double-blind trial, patients were randomized to receive daily oral supplementation with 1,000 mg of calcium and 400 IU of vitamin D or with placebo and 400 IU of vitamin D for 24 months. The effect of calcium supplementation on bone physiology was determined periodically using markers of bone turnover.

RESULTS

One hundred ninety-eight patients met the inclusion criteria and were followed up in the study. At baseline, there were no differences in markers of bone turnover between the groups. Patients with < or = 4 joints with active disease had higher serum levels of calcium and parathyroid hormone (PTH). Calcium-treated patients with < or =4 joints with active disease had lower levels of osteocalcin (OC). At followup, levels of 1,25-dihydroxyvitamin D3, PTH, OC, and urine phosphorus were lower in the group receiving calcium supplementation. Hypercalciuria, as determined by the urinary calcium-to-creatinine ratio, was not noted in 24-hour urine studies.

CONCLUSION

Levels of markers of bone physiology were significantly decreased in children with JRA receiving calcium supplementation. The physiologic changes were noted as early as 12 months into calcium supplementation. The hypercalciuria noted on spot testing of the urinary calcium-to-creatinine ratio was not demonstrated on further evaluation, nor did it lead to renal pathology. These findings suggest that the calcium supplementation met physiologic needs and caused an increased calcium loss in urine.

Bone mineral density in patients with juvenile idiopathic arthritis

Introduction. It is well known that juvenile idiopathic arthritis (JIA) as a chronic inflammatory disease with onset during the childhood, beside other complication, can lead to bone metabolism disturbance and osteoporosis. Objective. To assess bone mineral density (BMD) in children with JIA and to identify factors playing role in bone mineral disturbance. Methods. Seventy-five patients (26 male and 49 female) average disease duration 7.2 (2.4-16.8) years, and 73 age matched healthy control subjects (29 male and 44 female) participated in the study. Mean age of the groups was about 14.5 years. BMD was determined by dual x-ray absorptiometry (DEXA) of the lumbar spine (L2-L4). For further analysis we used the absolute value of BMD, expressed as g/cm2, Z score expressed as SD (relative value as standard deviation decline of normal BMD values of referent Italian population with identical age and gender), bone mineral content (BMC) as g/cm, and corrected BMD - BMDv as g/cm3. Results. Z score in the group of patients was significantly lower (-1.02?1.6) in comparison to the control group (-0.09?1.4; p<0.001). BMD, BMDv and BMC were also statistically lower in patients with JIA. The lowest Z score was found in patients with systemic onset (-2.63 SD). Z score showed a statistically significant positive correlation with arthritis course (polyarticular course had lower Z score), body mass index and standard deviation score for height and weight. Statistically significant negative correlation was detected in regard to Z score and glucocorticoid (GC) treatment duration, GC cumulative dose, number of joints with limited range of motion, radiological stage and functional class. Conclusion. The results showed a decreased BMD in patients with JIA in comparison to the control group. Systemic onset, polyarthritis, longer treatment with GC and higher cumulative dosage, as well as higher damage level (functional status and radiological stage) are factors playing negative role in bone metabolism in children with JIA.

[Diagnosis, prophylaxis and therapy of osteoporosis in juvenile idiopathic arthritis: consensus statement of the German Association for Pediatric Rheumatology]

In all subgroups of juvenile idiopathic arthritis (JIA), a pathologic loss of bone or the lack of increase in bone mass has been described in a high percentage of cases, even with new therapeutic approaches. The decrease in bone mass is correlated with the duration of active disease and the number of affected joints (cytokines, inactivity). In several studies, muscle mass was the strongest predictor of bone mass. A standardized diagnostic approach to the musculoskeletal system including measures of prophylaxis and therapy therefore seems to be mandatory for all children with JIA who do not achieve rapid remission. In this review, the diagnostic and therapeutic options are described and summarized in an algorithm.

Osteoporosis in children and adolescents

In recent years, the issue of low bone density in children and adolescents has attracted much attention. The classical definition of osteoporosis should be valid at any age, yet its practical applicability to children and adolescents remains a matter of debate and there is no consensus on a diagnosis based solely on the BMD value. The clinical relevance of uncomplicated low bone density in the young and its long-term consequences remain difficult to evaluate and there is only preliminary evidence that the BMD value is a predictor of fracture risk in growing subjects. Moreover, the interpretation of densitometric data in the young is difficult because the "normal" BMD values to be used for comparison are continuously changing with age, and in addition, depend on several variables, such as gender, body size, pubertal stage, skeletal maturation and ethnicity. Although Z-score values below -2 are generally considered a serious warning, most bone specialists make a diagnosis of osteoporosis in children and adolescents only in the presence of low BMD and at least one fragility fracture. The scope of this review is limited to presenting a picture of the available knowledge. The literature on fractures will be presented in detail, since fractures are one of the key elements in the debate. There are countless papers on fractures in childhood and adolescence, but very few of them attempt to identify fragility fractures, and still fewer develop the concept of osteoporosis in the young in relation to fractures. The different forms of primary and secondary osteoporosis, the more technical aspects of bone densitometry in pediatrics, and the delicate issue of treatment will be discussed only briefly.

Growth hormone increases final height in patients with juvenile idiopathic arthritis: data from a randomized controlled study

BACKGROUND

GH treatment stimulates growth in short children with juvenile idiopathic arthritis (JIA). The extent to which this therapy increases final height is not known.

METHODS

Thirty-one growth-retarded children with systemic and polyarticular idiopathic arthritis were enrolled in this controlled study. After a mean observational time of 8.4 yr, final height was reached in 13 patients (seven females and six males) treated with GH for a mean of 6.7 yr in a dose of 0.33 mg/kg body weight per week. Eighteen patients (12 females and six males) served as an untreated control group.

RESULTS

Mean increment in height in the treatment group was 1.6 +/- 0.8 SD, whereas the patients of the control group lost 0.7 +/- 1.8 SD. Overall, mean final height in the treatment group was -1.6 SD and in the control group -3.4 SD. More GH-treated patients reached a final height within target height than untreated patients (11 of 13 vs. four of 18). Disease activity markers had a significant influence on height outcome. After adjustment for baseline and average disease activity, the difference between treatment and control group was still significant (mean 1.5 SD). Patients with a moderate overall disease activity profited most from GH treatment. No adverse events were noted throughout the study.

CONCLUSION

Our data suggest that long-term GH therapy has a beneficial effect on growth and final height in the majority of growth retarded children with severe forms of JIA.

Osteoporosis in juvenile idiopathic arthritis--a practical approach to diagnosis and therapy

In all subgroups of juvenile idiopathic arthritis, a decrease in bone mass has been described in a high percentage of children. Recently, new pathogenetic concepts have identified muscle mass as the strongest predictor of bone mass and bone is now recognized as part of the musculoskeletal system. In addition, the sophisticated use of bone densitometry in pediatrics, including new measurement techniques, has provided the tools for a reliable assessment. A standardized diagnostic approach to the musculoskeletal system, including prophylaxis and therapy, is, therefore, mandatory in all children with JIA who do not achieve rapid remission. In this review, diagnostic and therapeutic options are being described and possibilities to incorporate them into clinical practice are suggested.

Musculoskeletal abnormalities of the tibia in juvenile rheumatoid arthritis

OBJECTIVE

To characterize local bone geometry, density, and strength, using peripheral quantitative computed tomography (pQCT), compared with general bone characteristics as measured using dual x-ray absorptiometry (DXA), and to assess their relationship to disease-related factors in children with juvenile rheumatoid arthritis (JRA).

METHODS

Forty-eight children ages 4-18 years with JRA (17 pauciarticular, 23 polyarticular, 8 systemic) were compared with age-matched healthy controls (n = 266). Measurements included cortical and trabecular bone geometry, density, and strength at the distal and midshaft tibia determined by pQCT, and whole-body, lumbar spine, and femoral neck measurements by DXA.

RESULTS

Methotrexate (MTX) was prescribed to 23 of 48 patients (47.9%) and glucocorticoids and MTX were prescribed to 15 of 48 patients (31.3%), with the greatest use in children with systemic JRA. All JRA patients had decreased tibia trabecular bone density, cortical bone size and strength, and muscle mass. Children with systemic JRA had lower femoral neck densities. Systemic JRA was associated with a shorter, less mineralized skeleton, while a narrower, less mineralized skeleton was observed in polyarticular JRA. The tibia diaphysis was narrower with decreased muscle mass, but normal, size-adjusted bone mineral in all subtypes indicated a localized effect of JRA on bone. Patients exposed to glucocorticoids and MTX or to glucocorticoids or MTX alone had greatly reduced trabecular density, cortical bone geometry properties, and bone mineral content, muscle mass, and bone strength.

CONCLUSION

Children with JRA have decreased skeletal size, muscle mass, trabecular bone density, cortical bone geometry, and strength. Not surprisingly, these bone abnormalities are more pronounced in children with greater disease severity.

rhGH Treatment in Corticosteroid-Treated Patients

Children and adolescents treated for chronic diseases have non-specific metabolic abnormalities that lead to decreased growth velocity and abnormal body composition, including severe osteoporosis, muscle wasting and increased fat mass. Glucocorticoid (GC) therapy plays a major role in the complex pathogenesis of these metabolic abnormalities. Recombinant human growth hormone (rhGH) therapy was introduced a few years ago to reduce the severe disease- and GC-related metabolic consequences of juvenile idiopathic arthritis, other chronic diseases, and renal transplantation. Short- and mid-term rhGH treatment has consistently proved effective in overcoming GC-induced growth suppression, with a marked interindividual variability in the growth response to rhGH treatment. Safety of rhGH treatment, concerning the progression of the disease and glucose tolerance, was good. Prolonged follow-up until achievement of adult height is needed to better evaluate the impact of rhGH treatment on growth and body composition and the long-term consequences of hyperinsulinism.

Can exercise influence low bone mineral density in children with juvenile rheumatoid arthritis?

PURPOSE

Low bone mineral density (BMD) is a common secondary condition associated with juvenile idiopathic arthritis (JIA). The purpose of this review was evaluate the literature pertinent to designing an effective, safe weight-bearing exercise program to reduce the risk of low BMD in children with JIA.

SUMMARY OF KEY POINTS

Thirty-seven articles on the risk of low BMD and children with JIA, weight-bearing interventions to improve BMD in healthy children, or safety and efficacy of exercise interventions with children with JIA were critiqued on the basis of their design. Three highly rated studies confirmed the multifactorial nature of low BMD in children with JIA, two highly rated studies support the efficacy of weight-bearing interventions for increasing BMD in children who are healthy, and one moderately rated study demonstrated the safety of low impact exercise by children with JIA.

STATEMENT OF CONCLUSIONS AND RECOMMENDATIONS FOR CLINICAL PRACTICE

Weight-bearing activities should be included in exercise programs for individuals with JIA, although more research is needed to determine the amount, duration, and frequency of weight-bearing activity needed to reduce the risk for low BMD.

Systematic review of effectiveness of bisphosphonates in treatment of low bone mineral density and fragility fractures in juvenile idiopathic arthritis

AIMS

To evaluate the currently available evidence for the effectiveness of bisphosphonates in children with low bone mineral density (BMD) and fragility fractures associated with juvenile idiopathic arthritis (JIA), and the safety of bisphosphonates in JIA and other conditions.

METHODS

Literature databases were searched using a structured search strategy. The effectiveness review included any studies of children with JIA treated with bisphosphonates. The safety review also included studies of osteogenesis imperfecta. Quantitative data analysis was not undertaken because of the heterogeneity of the studies; findings were summarised using tables and narrative synthesis.

RESULTS

Ninety four studies were identified. Sixteen studies (78 JIA children) were included in the effectiveness review: one randomised controlled trial, three controlled cohort studies, 11 case series, and one case report. At baseline, children had low BMD below the expected values for age and sex matched children. In all studies, treatment with bisphosphonates increased BMD compared with baseline: the mean percentage increase in spine BMD ranged from 4.5% to 19.1%. Overall, studies were heterogeneous and of variable quality. A total of 59 papers were included in the safety review; treatment durations were up to three years. The most common side effect was a flu-like reaction with intravenous treatment. This occurred during the first infusion and was transient; the symptoms were managed with paracetamol and did not occur during subsequent cycles.

CONCLUSIONS

Bisphosphonates are a promising treatment for low BMD and fragility fractures in children with JIA. However, the quality of the current evidence is variable and better studies are needed to more clearly assess their role.

Musculoskeletal and functional muscle-bone analysis in children with rheumatic disease using peripheral quantitative computed tomography

Bone demineralization is a severe complication of juvenile idiopathic arthritis (JIA) and other rheumatic diseases. To identify patients, who are at risk of bone disease, musculoskeletal analysis is performed. Furthermore, a more functional approach is needed to assess, whether bone strength is adequate for muscle force and whether muscle force is adequate for body size. In patients with a chronic disease it is most important to differentiate between primary bone problems and those that are secondary to low muscle force. To implement this approach, we measured musculoskeletal parameters of the radius in 94 patients with juvenile idiopathic arthritis of different subtypes and connective tissue disease using peripheral quantitative computed tomography. The four groups consisted of patients with oligoarticular (n = 31), polyarticular (n = 27), systemic JIA (n = 20) and connective tissue disease (CTD) (n = 16). All patients with systemic JIA and CTD and 56% of the patients with polyarticular JIA were under treatment with glucocorticoids. In general, the longer the duration of the disease and the more severe the subtype of the rheumatic disease, the shorter the height and the lower the bone density and bone strength parameters. Mean height, bone mineral content (BMC) and muscle cross-sectional area (CSA) were low for age, but muscle CSA was normal for height with the exception of patients with polyarticular disease. In the systemic JIA group the ratio of BMC per muscle CSA was decreased by -1.7+/-2.7 SD (P < 0.05), suggesting that bone strength was not adequately adapted to muscle force. This was even more expressed in females than in males (14 versus 3). These patients need closer follow up and potential specific therapeutic intervention.

Osteoporosis risk and low bone mineral density in women with physical disabilities

OBJECTIVES

To describe the results of bone mineral density (BMD) screening in women with different physical disabilities and to identify their risk factors for osteoporosis and use of strategies to prevent osteoporosis.

DESIGN

A cross-sectional descriptive study.

SETTING

Community.

PARTICIPANTS

Convenience sample of 429 community-residing women with different disabilities.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Peripheral BMD screening of the os calcis, using dual-energy x-ray absorptiometry. A self-administered survey addressed osteoporosis risk factors, use of osteoporosis prevention strategies, and previous recommendations for BMD screening or testing.

RESULTS

Based on World Health Organization criteria, 30.5% and 22.6% of the total sample had BMD values indicative of osteopenia and osteoporosis, respectively. The number of self-reported osteoporosis risk factors ranged from 0 to 10 (mean, 4.5+/-1.7). Subjects reported using few strategies to reduce their osteoporosis risks. One quarter of the women reported previous BMD screening or testing; about one third reported receiving recommendations for testing or screening by a health care provider.

CONCLUSIONS

More than half of the sample had low BMD, and it was present in premenopausal as well as menopausal women. Despite low BMD and the presence of osteoporosis risk factors, less than a third of the women previously had BMD testing or screening or recommendations for such testing. Because low BMD is common in women with disabilities, greater attention must be directed toward their risk for osteoporosis and osteoporotic fractures. Prevention strategies to reduce osteoporosis risk should be considered, although their efficacy is not yet known in populations with disabilities.

Osteoporosis in chronically ill children

Gains in bone mass are very rapid during adolescence and peak bone mass, the most important determinant of osteoporosis, is attained by early adulthood. Glucocorticoids, widely used in children with chronic illness, are known to impact bone mass and quality. In addition, disease and treatment-related factors, nutrient and hormone deficiencies and decreased physical activity may all negatively affect bone mass accrual. Although decreased bone density is increasingly recognized in chronically ill children, current knowledge of the epidemiology, diagnosis and optimal treatment of pediatric secondary osteoporosis is limited. In addition to bone densitometry, biochemical and radiographic tests should be used in the diagnosis of osteoporosis. Bone histomorphometry may be needed in selected situations. At risk children should be advised to ensure sufficient calcium and vitamin D intake and weight bearing physical activity. Growth and pubertal development require careful assessment because of their close correlation with bone formation. Given limited experience with bisphosphonates, it seems prudent to target antiresorptive therapy to those children who have developed symptomatic disease. Ideally this should be done in controlled settings. Early identification and adequate intervention, in selected cases with bisphosphonates, is needed in order to prevent deleterious skeletal complications of osteoporosis in chronically ill children.

Bone disease in pediatric rheumatologic disorders

Children with rheumatic disorders have multiple risk factors for impaired bone health, including delayed growth and development, malnutrition, decreased weight-bearing activity, inflammation, and glucocorticoid therapy. The impact of rheumatic disease during childhood may be immediate, resulting in fragility fractures, or delayed, because of suboptimal peak bone mass accrual. Recent years have seen increased interest in the effects of pediatric rheumatic disorders on bone mineralization, such as juvenile rheumatoid arthritis, systemic lupus erythematosus, and juvenile dermatomyositis. This review outlines the expected gains in bone size and mass during childhood and adolescence, and summarizes the advantages and disadvantages of available technologies for the assessment of skeletal growth and fragility in children. The varied threats to bone health in pediatric rheumatic disorders are reviewed, with emphasis on recent insights into the molecular mechanisms of inflammation-induced bone resorption. The literature assessing bone deficits and risk factors for impaired bone health in pediatric rheumatic disorders is reviewed, with consideration of the strengths and limitations of prior studies. Finally, future research directions are proposed.

Frequency of osteopenia in adolescents with early-onset juvenile idiopathic arthritis: a long-term outcome study of one hundred five patients

OBJECTIVE

To determine the frequency of low bone mineral content (BMC) and low bone mineral density (BMD) as long-term complications in adolescents with early-onset juvenile idiopathic arthritis (JIA), and to identify disease variables, patient characteristics, and biochemical bone markers related to low bone mass.

METHODS

One hundred five (87%) of 121 adolescent patients with early-onset JIA (ages 13-19 years, 80 girls and 25 boys, mean age at onset of JIA 2.8 years), from a cohort first admitted to the hospital between 1980 and 1985, were assessed after a mean disease duration of 14.2 years. BMC and BMD of the total body, the lumbar spine at L2-L4, and the femoral neck were measured by dual-energy x-ray absorptiometry. Age- and sex-specific reference values from a pooled, healthy reference population were used to calculate Z scores. Low bone mass was defined as a Z score less than -1 SD.

RESULTS

Among the 103 adolescent JIA patients who underwent total-body imaging, 41% had low total-body BMC and 34% had low total-body BMD. Compared with adolescent JIA patients who had normal total-body BMC, those with low BMC had lower mean weight (P < 0.001), height (P < 0.001), lean mass (P < 0.001), and remission rates (P = 0.016), had longer duration of active disease (P = 0.013), had higher numbers of active and mobility-restricted joints (P < 0.001 and P = 0.001, respectively), had more disability (P = 0.011), had higher frequencies of joint erosions (P < 0.001), and had higher erythrocyte sedimentation rates (P = 0.033). In multiple linear regression analyses of total-body BMC, 88% of the variance was explained by the duration of active disease, the number of joints with restricted mobility, the bone area, urinary deoxypyridinoline values, age, weight, and height.

CONCLUSION

Forty-one percent of the adolescents with early-onset JIA had low bone mass >11 years after disease onset. The development of low total-body BMC was related to the duration of active disease, disease severity, measures of bone resorption, weight, and height.

Ocular complications and visual outcome in juvenile chronic arthritis: a 25-year follow-up study

OBJECTIVE

Assessment of longterm ophthalmic outcome in juvenile chronic arthritis (JCA) with emphasis on visual acuity and identification of disease-related parameters associated with rheumatic eye affection.

MATERIAL

Sixty-five adults (52 females, 13 males) with a history of or still active JCA were assessed an average of 26.7 years after disease onset.

METHODS

Cross-sectional, longterm, follow-up study including complete ophthalmological and rheumatological examinations.

RESULTS

Evidence of ocular complications was found in 13 subjects (20%): 10 had had recurrent iritis, two band keratopathy, and one diplopia due to rheumatoid eye muscle involvement. The three single eyes with poor sight (<0.1) were all in the complication subgroup. Binocularly, all but one patient scored at least 6/9 as best corrected visual acuity; one, however, had severe glaucoma-impaired visual fields. The refractive range was -8.12 to +6.0 D. There were no cases of keratoconjunctivitis sicca. Iritis was associated with early disease onset (p = 0.02), longer disease duration (p = 0.02) and a positive antinuclear antibodies (ANA) (p = 0.02).

CONCLUSION

Ophthalmic complications were recorded in 20% of the study group, primarily in ANA positive patients with pauciarticular onset JCA. In addition to the two patients with severely affected bilateral visual status (3%), one of the 65 patients had acquired unilateral blindness. Half of the complications were late in that they were first recorded after the age of 16 years. Otherwise, the findings were in keeping with other studies of visual prognosis using non-selected series.

Outcome in adults with juvenile idiopathic arthritis: a quality of life study

OBJECTIVE

To evaluate quality of life (QOL) in adults with juvenile idiopathic arthritis (JIA), using validated measures of functional disability and generic health status, and to quantify their educational attainment and employment status.

METHODS

The adult rheumatology departmental database was used to identify patients. Functional disability and generic health status/QOL were assessed by the Health Assessment Questionnaire (HAQ) and the Short Form 36-item health profile (SF-36), respectively. Educational achievement and employment status were assessed by questionnaire.

RESULTS

Complete data were available for 82 of the 101 patients identified. The median age of patients was 30 years, and the median disease duration was 21 years. No deaths were recorded. All subtypes of JIA were represented. Thirty-nine percent of patients had active disease (based on the physician global assessment scale score). The median HAQ score was 1.125 (range 0-3). SF-36 scores for bodily pain, general health, physical functioning, vitality, emotion, and social isolation were significantly worse in patients compared with controls, and this trend increased with increasing age of the patients and disease duration. The SF-36 mental summation scores of patients were low compared with those of controls, for all subtypes of JIA, and this finding was independent of the degree of functional disability (by HAQ and SF-36 physical summation scores). The educational attainment of patients was comparable to that of local controls, but unemployment rates for patients were 3-fold higher than those for controls.

CONCLUSION

This is the largest study in which the SF-36 was used to assess generic health status and QOL in adults with JIA. Many patients had active disease in adulthood, and although the physical outcome of adults with JIA is relatively good, a profound effect on generic health status and QOL was demonstrated for all types of JIA. Furthermore, despite excellent educational attainment, there was a high rate of unemployment among patients.

Juvenile rheumatoid arthritis

Progress in achieving international consensus concerning the classification of juvenile idiopathic arthritis has been made, although further refinement and validation of these criteria is needed. It is hoped that this will facilitate more effective international collaboration in the study of these diseases, because much remains to be learned about genetic susceptibility, causation, pathogenesis, and treatment. Attention to the unique aspects of chronic arthritis in children such as impaired growth and macrophage activation syndrome may help to reduce disease-related morbidity and mortality. New biologic agents have substantially enhanced the treatment of JRA. The identification of reliable predictors of disease course and outcome is important in the rational and timely application of new therapies.

Bone metabolism in childhood rheumatic disease

There is an increasing appreciation among physicians about the importance of bone health in children as a potential modifiable risk factor for development of osteoporosis later in life. Many unanswered questions about normal pediatric bone health make the treatment and clinical investigation of bone disease in children with chronic rheumatic diseases challenging. Understanding normal bone biology along with the epidemiology and diagnosis of osteoporosis is the key to the understanding of the potential for abnormal bone metabolism in the juvenile rheumatic diseases.

GH therapy in juvenile chronic arthritis: results of a two-year controlled study on growth and bone

Disturbance of growth frequently occurs in children suffering from juvenile chronic arthritis (JCA). Recognition of growth impairment is important because reduced final height is one of the permanent consequences. The aim of this study was to evaluate the efficacy and safety of human GH (hGH) in growth-retarded prepubertal children with JCA. Thirty-five children were tested for GH deficiency (GHD) and randomly assigned to a study and an untreated control group; five were GH deficient and were part of the GHD group. All received glucocorticoids. The study group was treated with 1 IU/kg BW.wk hGH; the GHD group was given 0.5 IU. During 2 yr of hGH treatment growth velocity and height SD score increased compared with baseline values. There was a marked increase in growth velocity in the treated groups, but also some increase in the control group. Plasma levels of IGF-I and IGF-binding protein-3 increased with GH treatment. These results suggest that hGH might be useful in the treatment of growth impairment in JCA. GH may counteract the adverse effects of glucocorticoid therapy, but its effect is dependent on the disease activity. Long-term controlled studies are needed to determine the risks and benefits of GH therapy in JCA.

Osteoporosis

Bone mass is determined primarily by genetic influences, but exogenous factors may also play a major role. The prevention of osteoporosis can start at childhood. Optimal achievement of peak bone mass during childhood and adolescence is important to minimize future fracture risk. Chronic inflammatory diseases can have a detrimental effect on bone mass through a variety of mechanisms. Different diagnostic methods for detecting osteoporosis (eg, dual x-ray absorptiometry, quantitative computed tomography, ultrasounds) are in use or under investigation. New treatment options are available; among these, the use of bisphosphonates seems to be the more promising approach.

Prognostic factors in juvenile idiopathic arthritis

Prognostic factors in juvenile arthritis are related to many variables that must be evaluated according to the different subtypes. The International League of Associations of Rheumatologists (ILAR) recently proposed six different categories referred to as the Durban criteria, under the eponym of juvenile idiopathic arthritis (JIA). The aim of this classification was to define homogeneous groups according to their clinical and biologic features. The prognostic factors were classified into the different categories of JIA. A poor outcome in the systemic form correlated with markers of disease activity, such as fever and polyarticular involvement, within the first 6 months. The risk of joint destruction in oligoarthritis correlated with the severity of arthritis within the first 2 years. Polyarthritis with positive rheumatoid factor is associated with marked disability in adulthood. In a group of psoriatic patients, the risk of developing sacroiliitis is higher in male and HLA-B27-positive patients. Patients with enthesitis-related arthritis with lower limb, knee, and tarsal involvement also are at greater risk of developing sacroiliitis. Chronic uveitis is a complication of JIA observed mainly in patients with oligoarthritis associated with positive antinuclear antibodies in serum. Secondary amyloidosis is observed mainly in children with systemic JIA. The long-term outcome must be discussed according to the various therapies. Corticosteroids contribute to growth retardation and osteoporosis, for which the use of human recombinant growth hormone and biphosphonates may be an option. Newer encouraging therapies such as anticytokines have been proposed for children with active disease. Autologous stem cell transplantation is being evaluated in some centers with promising results; however, it has a high rate of mortality. Further discussion regarding which patients should undergo autologous stem cell transplantation is needed, as is further discussion regarding the technical adaptations necessary.