Biphosphonate-induced radiographic changes in two pediatric patients with rheumatic diseases

Markers of bone turnover in patients with epilepsy and their relationship to management of bone diseases induced by antiepileptic drugs

Data from cross-sectional and prospective studies revealed that patients with epilepsy and on long-term treatment with antiepileptic drugs (AEDs) are at increased risk for metabolic bone diseases. Bone diseases were reported in about 50% of patients on AEDs. Low bone mineral density, osteopenia/osteoporosis, osteomalacia, rickets, altered concentration of bone turnover markers and fractures were reported with phenobarbital, phenytoin, carbamazepine, valproate, oxcarbazepine and lamotrigine. The mechanisms for AEDs-induced bone diseases are heterogeneous and include hypovitaminosis D, hypocalcemia and direct acceleration of bone loss and/or reduction of bone formation. This article reviews the evidence, predictors and mechanisms of AEDs-induced bone abnormalities and its clinical implications. For patients on AEDs, regular monitoring of bone health is recommended. Prophylactic administration of calcium and vitamin D is recommended for all patients. Treatment doses of calcium and vitamin D and even anti-resorptive drug therapy are reserved for patients at high risk of pathological fracture.

Markers of bone turnover in patients with epilepsy and their relationship to management of bone diseases induced by antiepileptic drugs

Data from cross-sectional and prospective studies revealed that patients with epilepsy and on long-term treatment with antiepileptic drugs (AEDs) are at increased risk for metabolic bone diseases. Bone diseases were reported in about 50% of patients on AEDs. Low bone mineral density, osteopenia/osteoporosis, osteomalacia, rickets, altered concentration of bone turnover markers and fractures were reported with phenobarbital, phenytoin, carbamazepine, valproate, oxcarbazepine and lamotrigine. The mechanisms for AEDs-induced bone diseases are heterogeneous and include hypovitaminosis D, hypocalcemia and direct acceleration of bone loss and/or reduction of bone formation. This article reviews the evidence, predictors and mechanisms of AEDs-induced bone abnormalities and its clinical implications. For patients on AEDs, regular monitoring of bone health is recommended. Prophylactic administration of calcium and vitamin D is recommended for all patients. Treatment doses of calcium and vitamin D and even anti-resorptive drug therapy are reserved for patients at high risk of pathological fracture.

Radiographic and MR Imaging Findings of the Spine after Bisphosphonate Treatment, in a Child with Idiopathic Juvenile Osteoporosis

Bisphosphonates are employed with increasing frequency in various pediatric disorders, mainly associated with osteoporosis. After cessation of bisphosphonate treatment in children, skeletal radiologic changes have been documented including dense metaphyseal lines of the long bones and "bone in bone" appearance of the vertebrae. However, the evolution of these radiographic changes has not been fully explored. We describe the MR imaging appearance of the spine that, to our knowledge, has not been previously addressed in a child with idiopathic juvenile osteoporosis who had received bisphosphonates and emphasize the evolution of the radiographic findings of the spine and pelvis over a four-year period.

A survey of steroid-related osteoporosis diagnosis, prevention and treatment practices of pediatric rheumatologists in North America

BACKGROUND

The purpose of our study is to assess practices of North American pediatric rheumatologists regarding monitoring, prevention, and treatment of low bone mineral density (BMD) in children on long-term glucocorticoid treatment. Long-term glucocorticoid therapy is associated with accelerated bone loss. Children with JIA and lupus have low baseline BMD and incident vertebral fractures commonly occur in these groups of patients even after a relatively short period of time being on systemic glucocorticoids. There are no established guidelines for identification, prevention, and treatment of glucocorticoid-induced bone loss in children.

METHODS

A cross-sectional online survey was conducted with 199 physicians who were listed in the ACR database as practicing pediatric rheumatology in North America.

RESULTS

86 physicians (43%) responded; 87% were board-certified in pediatric rheumatology. 95% used dual energy X-ray absorptiometry as their primary modality for assessing BMD. 79% "rarely" or "never" obtained a baseline BMD measurement prior to initiation of glucocorticoid therapy. 42% of respondents followed BMD annually. 93% "frequently" or "always" prescribed calcium for patients on long-term corticosteroid therapy; 81% "frequently" or "always" prescribed vitamin D. In patients diagnosed with osteoporosis, 35%-50 % of the practitioners "sometimes", "frequently" or "always" prescribed bisphosphonates. Bisphosphonates are prescribed at similar rates for male and female patients, and slightly more frequently for pubertal than for pre-pubertal patients. 96% of respondents "rarely" or "never" prescribed calcitonin for patients on long-term glucocorticoid therapy; 92% "rarely" or "never" prescribe this medication for patients with known osteopenia or osteoporosis.

CONCLUSIONS

Utilization of DXA in children on long-term corticosteroid therapy varies greatly among North American pediatric rheumatologists. Most respondents do not screen for low BMD on a regular basis despite acknowledging the risks of bone loss in this population. Broad consensus appears to be present among practitioners favoring the prescription of calcium and vitamin D for patients receiving long-term corticosteroid therapy. Relatively few respondents consistently recommend bisphosphonate therapy, even for patients with known low bone density; calcitonin is rarely used. These data underscore the need for studies to acquire specific data on bone loss, and its prevention and treatment in young patients on long-term glucocorticoid therapy.

Bisphosphonate therapy for children and adolescents with secondary osteoporosis

BACKGROUND

Children with chronic illnesses are at increased risk for reductions in bone strength and subsequent fractures (osteoporosis), either due to the impact of the underlying condition on skeletal development or due to the osteotoxic effect of medications (e.g., glucocorticoids) used to treat the chronic illness. Bisphosphonates are being administered with increasing frequency to children with secondary osteoporosis; however, the efficacy and harm of these agents remains unclear.

OBJECTIVES

To examine the efficacy and harm of bisphosphonate therapy in the treatment and prevention of secondary osteoporosis in children and adolescents.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (Issue 4, 2006), MEDLINE, EMBASE, CINAHL and ISI Web of Science (inception-December 2006). Further literature was identified through expert contact, key author searches, scanning reference lists of included studies, and contacting bisphosphonate manufacturers.

SELECTION CRITERIA

Randomized, quasi-randomized, controlled clinical trials, cohort, and case controls of bisphosphonate(s) in children 0-18 years of age with at least one low-trauma fracture event or reductions in bone mineral density in the context of secondary osteoporosis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed quality. Case series were used for supplemental harms-related data.

MAIN RESULTS

Six RCTs, two CCTs, and one prospective cohort (n=281 children) were included and classified into osteoporosis due to: 1) neuromuscular conditions (one RCT) and 2) chronic illness (five RCTs, two CCTs, one cohort). Bisphosphonates examined were oral alendronate, clodronate, and intravenous (IV) pamidronate. Study quality varied. Harms data from 23 case series (n=241 children) were used. Heterogeneity precluded statistically combining the results. Percent change or Z-score change in lumbar spine areal BMD from baseline were consistently reported. Two studies carried out between-group analyses; one showed no significant difference (using oral alendronate in anorexia nervosa) while the other demonstrated a treatment effect on lumbar spine with IV pamidronate in burn patients. Frequently reported harms included the acute phase reaction, followed by gastrointestinal complaints, and bone/muscle pain.

AUTHORS' CONCLUSIONS

The results justify further evaluation of bisphosphonates among children with secondary osteoporosis. However, the evidence does not support bisphosphonates as standard therapy. Short-term (3 years or less) bisphosphonate use appears to be well-tolerated. An accepted criterion for osteoporosis in children, a standardized approach to BMD reporting, and examining functional bone health outcomes (e.g., fracture rates) will allow for appropriate comparisons across studies.

Advances in the diagnosis and treatment of osteoporosis

Although severely low bone density is relatively rare in the pediatric population, it can be a significant problem in many patients with chronic illness. As peak bone formation occurs during adolescence, it is crucial that pediatricians and other care providers for this patient population recognize the significance of attainment of adequate bone. Dietary intake of vitamin D and calcium should be optimized, and correction of underlying causes of poor bone density should occur whenever possible. Assessment of bone density is difficult, as each technology available has problems, and none of the technologies are well-associated with fracture risk in pediatric patients. Once diagnosis of severely low bone density is established, treatment options are limited and poorly studied. The benefits of bisphosphonate therapy appear to outweigh the risks in patients with low bone density and frequent fragility fractures, and it appears that most improvement with bisphosphonates occurs within the first 2 to 4 years. Evidence, however, is emerging that once off therapy, bone turnover remains decreased for at least several years. During that time, improvements in bone density are decreased. Many questions remain regarding duration of therapy with bisphosphonate therapy and the long-term effects on the children who receive this medication. Anabolic therapies may become important in the future, but there is currently extremely limited information regarding their use in pediatrics.

Systemic juvenile idiopathic arthritis: diagnosis, management, and outcome

Systemic juvenile idiopathic arthritis is a heterogeneous form of arthritis in childhood and represents 10-20% of all juvenile idiopathic arthritides in the Caucasian populations of Northern America and Europe. Up to 30% of patients will still have active disease after 10 years, and morbidity within this group is high. Secondary complications (e.g. growth failure, osteoporosis, deformities, and loss of function) and amyloidosis are the medical sequelae, but there are also serious developmental and social consequences. The medical treatment of patients who are at the more severe end of the disease spectrum is unsatisfactory; however, new therapies that might improve prognosis, such as autologous stem-cell transplantation and approaches for blocking interleukin-6 signaling, are currently being assessed in clinical trials.

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.