Treatment of osteopenia and osteoporosis in renal transplant children and adolescents

Cerebral palsy and bisphosphonates - and what can be learned from other types of secondary osteoporosis in children: A scoping review

AIM

We aimed to improve bone health management of children with cerebral palsy (CP) by reviewing studies investigating bisphosphonate therapy in children with CP and other types of secondary osteoporosis.

METHODS

We included trials on bisphosphonate treatment reporting any direct bone measurement or fracture outcome. All studies of patients with CP were included. We also included all controlled trials of children with secondary bone fragility as well as observational studies with ≥20 participants or at least 3 years of follow-up. Studies were assessed according to PRISMA guidelines using the RoB2-tool and the Newcastle-Ottawa Scale.

RESULTS

We reviewed 1104 studies and found 37 eligible. Some studies were sufficiently homogeneous to include in a meta-analysis, and we found a 1-year effect on lumbar spine bone mineral density (BMD) Z-score of +0.65 after oral and + 1.21 after intravenous bisphosphonates in children with secondary osteoporosis. Further, data on adverse events and post-treatment follow-up were reviewed. Limitations were heterogeneity and small size of the included studies.

CONCLUSION

Meta-analysis consistently showed significant BMD increases with bisphosphonates in children with secondary osteoporosis. Direct evidence of the effect of bisphosphonates on reducing fractures is lacking. We found no reports of long-term adverse events yet longer studies are needed.

Efficacy and safety of bisphosphonates on childhood osteoporosis secondary to chronic illness or its treatment: a meta-analysis

Background:

Bisphosphonates are a type of medication that prevents the loss of bone density. Secondary childhood osteoporosis reduces bone strength and results in an increased risk of fragility fracture. This meta-analysis aims to explore the efficacy and safety of bisphosphonates on secondary childhood osteoporosis.

Methods:

We performed a systematic search of PubMed, Cochrane library, and Web of Science databases up to 31 July 2022 to screen for random clinical trials (RCTs) on bisphosphonate treatment for childhood secondary osteoporosis. Data from selected studies, mainly changes in lumbar spine (LS) bone mineral density (BMD), changes in LS BMD Z-scores, fracture events, and adverse events (AEs), were extracted and analyzed.

Results:

Nine RCTs (n = 429 in total) were included in our meta-analysis. The meta-analysis indicated that bisphosphonates improved the changes in LS BMD [mean difference (MD) = 0.04, 95% confidence intervals (CIs) = 0.01–0.07, p < 0.01] and LS BMD Z-scores [MD = 0.52, 95% CI = 0.23–0.81, p < 0.01]. Use of bisphosphonates did not increase the risk of AEs [odds ratio (OR) = 1.61, 95% CI = 0.87–2.99, p = 0.13]. Subgroup analysis showed that routes of administration, but not causes of secondary osteoporosis, might influence the efficacy of bisphosphonates. IV bisphosphonates close to significantly improved the incidence of fracture (OR = 0.34, 95% CI: 0.11–1.08, p = 0.07).

Conclusions:

The use of bisphosphonates improves LS BMD without increasing AE rates, which supports the clinical use of bisphosphonates in secondary childhood osteoporosis. Further large RCTs are still warranted, especially for their long-term effects on fracture rates.

Clinical practice guidelines for optimizing bone health in Korean children and adolescents

The Committee on Pediatric Bone Health of the Korean Society of Pediatric Endocrinology has newly developed evidence-based clinical practice guidelines for optimizing bone health in Korean children and adolescents. These guidelines present recommendations based on the Grading of Recommendations, which includes the quality of evidence. In the absence of sufficient evidence, conclusions were based on expert opinion. These guidelines include processes of bone acquisition, definition, and evaluation of low bone mineral density (BMD), causes of osteoporosis, methods for optimizing bone health, and pharmacological treatments for enhancing BMD in children and adolescents. While these guidelines provide current evidence-based recommendations, further research is required to strengthen these guidelines.

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.

Promoting bone health in children and adolescents following solid organ transplantation

Solid organ transplantation in children and adolescents provides many benefits through improving critical organ function, including better growth, development, cardiovascular status, and quality of life. Unfortunately, bone status may be adversely affected even when overall status is improving, due to issues with pre-existing bone disease as well as medications and nutritional challenges inherent post-transplantation. For all children and adolescents, bone status entering adulthood is a critical determinant of bone health through adulthood. The overall health and bone status of transplant recipients benefits from attention to regular physical activity, good nutrition, adequate calcium, phosphorous, magnesium and vitamin D intake and avoidance/minimization of soda, extra sodium, and obesity. Many immunosuppressive agents, especially glucocorticoids, can adversely affect bone function and development. Minimizing exposure to "bone-toxic" medications is an important part of promoting bone health in children post-transplantation. Existing guidelines detail how regular monitoring of bone status and biochemical markers can help detect bone abnormalities early and facilitate valuable bone-directed interventions. Attention to calcium and vitamin D supplementation, as well as tapering and withdrawing glucocorticoids as early as possible after transplant, can provide best bone outcomes for these children. Dual-energy X-ray absorptiometry can be useful to detect abnormal bone mass and fracture risk in this population and newer bone assessment methods are being evaluated in children at risk for poor bone outcomes. Newer bone therapies being explored in adults with transplants, particularly bisphosphonates and the RANKL inhibitor denosumab, may offer promise for children with low bone mass post-transplantation.

Guidelines for the management of children at risk of secondary bone fragility: Expert opinion of a French working group

The current French national guidelines were elaborated by a working group consisting of experts in the field of pediatric endocrinology, rheumatology, hepatogastroenterology, nephrology, and pneumology. A systematic search was undertaken of the literature published between 2008 and 2018 and indexed in PubMed. The recommendations developed were then validated by an external evaluation group comprising representatives from the various highly specialized fields in pediatrics, representatives of the societies and groups supporting the development of the guidelines, and representatives of different healthcare professions. The objective of these guidelines was to detail the current optimal management of children at risk of secondary bone fragility.

Interventions for preventing bone disease in kidney transplant recipients

BACKGROUND

People who have chronic kidney disease (CKD) have important changes to bone structure, strength, and metabolism. Children experience bone deformity, pain, and delayed or impaired growth. Adults experience limb and vertebral fractures, avascular necrosis, and pain. The fracture risk after kidney transplantation is four times that of the general population and is related to Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) occurring with end-stage kidney failure, steroid-induced bone loss, and persistent hyperparathyroidism after transplantation. Fractures may reduce quality of life and lead to being unable to work or contribute to community roles and responsibilities. Earlier versions of this review have found low certainty evidence for effects of treatment. This is an update of a review first published in 2005 and updated in 2007.

OBJECTIVES

This review update evaluates the benefits and harms of interventions for preventing bone disease following kidney transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 16 May 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

RCTs and quasi-RCTs evaluating treatments for bone disease among kidney transplant recipients of any age were eligible.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial risks of bias and extracted data. Statistical analyses were performed using random effects meta-analysis. The risk estimates were expressed as a risk ratio (RR) for dichotomous variables and mean difference (MD) for continuous outcomes together with the corresponding 95% confidence interval (CI). The primary efficacy outcome was bone fracture. The primary safety outcome was acute graft rejection. Secondary outcomes included death (all cause and cardiovascular), myocardial infarction, stroke, musculoskeletal disorders (e.g. skeletal deformity, bone pain), graft loss, nausea, hyper- or hypocalcaemia, kidney function, serum parathyroid hormone (PTH), and bone mineral density (BMD).

MAIN RESULTS

In this 2019 update, 65 studies (involving 3598 participants) were eligible; 45 studies contributed data to our meta-analyses (2698 participants). Treatments included bisphosphonates, vitamin D compounds, teriparatide, denosumab, cinacalcet, parathyroidectomy, and calcitonin. Median duration of follow-up was 12 months. Forty-three studies evaluated bone density or bone-related biomarkers, with more recent studies evaluating proteinuria and hyperparathyroidism. Bisphosphonate therapy was usually commenced in the perioperative transplantation period (within 3 weeks) and regardless of BMD. Risks of bias were generally high or unclear leading to lower certainty in the results. A single study reported outcomes among 60 children and adolescents. Studies were not designed to measure treatment effects on fracture, death or cardiovascular outcomes, or graft loss.Compared to placebo, bisphosphonate therapy administered over 12 months in transplant recipients may prevent fracture (RR 0.62, 95% CI 0.38 to 1.01; low certainty evidence) although the 95% CI included the possibility that bisphosphonate therapy might make little or no difference. Fracture events were principally vertebral fractures identified during routine radiographic surveillance. It was uncertain whether any other drug class decreased fracture (low or very low certainty evidence). It was uncertain whether interventions for bone disease in kidney transplantation reduce all-cause or cardiovascular death, myocardial infarction or stroke, or graft loss in very low certainty evidence. Bisphosphonate therapy may decrease acute graft rejection (RR 0.70, 95% CI 0.55 to 0.89; low certainty evidence), while it is uncertain whether any other treatment impacts graft rejection (very low certainty evidence). Bisphosphonate therapy may reduce bone pain (RR 0.20, 95% CI 0.04 to 0.93; very low certainty evidence), while it was very uncertain whether bisphosphonates prevent spinal deformity or avascular bone necrosis (very low certainty evidence). Bisphosphonates may increase to risk of hypocalcaemia (RR 5.59, 95% CI 1.00 to 31.06; low certainty evidence). It was uncertain whether vitamin D compounds had any effect on skeletal, cardiovascular, death, or transplant function outcomes (very low certainty or absence of evidence). Evidence for the benefits and harms of all other treatments was of very low certainty. Evidence for children and young adolescents was sparse.

AUTHORS' CONCLUSIONS

Bisphosphonate therapy may reduce fracture and bone pain after kidney transplantation, however low certainty in the evidence indicates it is possible that treatment may make little or no difference. It is uncertain whether bisphosphonate therapy or other bone treatments prevent other skeletal complications after kidney transplantation, including spinal deformity or avascular bone necrosis. The effects of bone treatment for children and adolescents after kidney transplantation are very uncertain.

State-of-the-art immunosuppression protocols for pediatric renal transplant recipients

Immunosuppressive protocols used in pediatric kidney transplantation have changed substantially within the last decade. Many transplant centers now focus on the use of tacrolimus and mycophenolate mofetil in combination with early steroid withdrawal, frequently combined with antibody induction therapy. However, this approach is mainly based on treatment efficacy and-compared to other immunosuppressive regimens used in this context-leads to higher rates of viral infections in patients. In this review I assess data from prospective, interventional trials of immunosuppressive therapy in pediatric kidney transplantation. However, since there is a paucity of randomized controlled trials, I also describe the results of studies with weaker designs. The advantages and disadvantages of different immunosuppressive strategies are discussed. Within this framework I suggest ideas for individualized immunosuppressive regimens based on different stratificators that could effect a change from a 'one size fits all' to a tailored approach for initial and maintenance immunosuppressive therapy after renal transplantation in the pediatric setting.

Consensus guidelines on the use of bisphosphonate therapy in children and adolescents

Bisphosphonate therapy is the mainstay of pharmacological intervention in young people with skeletal fragility. The evidence of its use in a variety of conditions remains limited despite over three decades of clinical experience. On behalf of the Australasian Paediatric Endocrine Group, this evidence-based consensus guideline presents recommendations and discusses the graded evidence (using the GRADE system) for these recommendations. Primary bone fragility disorders such as osteogenesis imperfecta are considered separately from osteoporosis secondary to other clinical conditions (such as cerebral palsy, Duchenne muscular dystrophy). The use of bisphosphonates in non-fragility conditions, such as fibrous dysplasia, avascular necrosis, bone cysts and hypercalcaemia, is also discussed. While these guidelines provide an evidence-based approach where possible, further research is required in all clinical applications in order to strengthen the recommendations made.

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.

Efficacy and Safety of Bisphosphonates for Low Bone Mineral Density After Kidney Transplantation: A Meta-Analysis

In patients with low bone mineral density (BMD) after kidney transplantation, the role of bisphosphonates remains unclear. We performed a systematic review and meta-analysis to investigate the efficacy and safety of bisphosphonates.We retrieved trials from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception through May 2015. Only randomized controlled trials that compared bisphosphonate-treated and control groups of patients with low bone mineral density after kidney transplantation were included. The primary outcomes were the percent change in BMD, the absolute change in BMD, and the BMD at the end of study at the lumbar spine. The results were expressed as the mean difference (MD) or relative risk (RR) with the 95% confidence interval (CI). We used a random-effects model to pool the outcomes.We included 17 randomized controlled trials with 1067 patients. Only 1 included trial was found to be at low risk of bias. The rest of the included studies were found to have high to uncertain risk of bias. Compared with the control group, those who received bisphosphonates had a significant increase in percent change in BMD (mean difference [MD] = 5.51, 95% confidence interval [CI] 3.22-7.79, P < 0.00001) and absolute change in BMD (MD = 0.05, 95% CI 0.04-0.05, P < 0.00001), but a nonsignificant increase in BMD at the end of the study (MD = 0.02, 95% CI -0.01 to 0.05, P = 0.25) at the lumbar spine. Bisphosphonates resulted in a significant improvement in percent change in BMD (MD = 4.95, 95% CI 2.57-7.33, P < 0.0001), but a nonsignificant improvement in absolute change in BMD (MD = 0.03, 95% CI -0.00 to 0.06, P = 0.07) and BMD at the end of the study (MD = -0.01, 95% CI -0.04 to 0.02, P = 0.40) at the femoral neck. No significant differences were found in vertebral fractures, nonvertebral fractures, adverse events, and gastrointestinal adverse events.Bisphosphonates appear to have a beneficial effect on BMD at the lumbar spine and do not significantly decrease fracture events in recipients. However, the results should be interpreted cautiously due to the lack of robustness and the heterogeneity among studies.

Mineral and bone disorder after kidney transplantation

After successful kidney transplantation, accumulated waste products and electrolytes are excreted and regulatory hormones return to normal levels. Despite the improvement in mineral metabolites and mineral regulating hormones after kidney transplantation, abnormal bone and mineral metabolism continues to present in most patients. During the first 3 mo, fibroblast growth factor-23 (FGF-23) and parathyroid hormone levels decrease rapidly in association with an increase in 1,25-dihydroxyvitamin D production. Renal phosphate excretion resumes and serum calcium, if elevated before, returns toward normal levels. FGF-23 excess during the first 3-12 mo results in exaggerated renal phosphate loss and hypophosphatemia occurs in some patients. After 1 year, FGF-23 and serum phosphate return to normal levels but persistent hyperparathyroidism remains in some patients. The progression of vascular calcification also attenuates. High dose corticosteroid and persistent hyperparathyroidism are the most important factors influencing abnormal bone and mineral metabolism in long-term kidney transplant (KT) recipients. Bone loss occurs at a highest rate during the first 6-12 mo after transplantation. Measurement of bone mineral density is recommended in patients with estimated glomerular filtration rate > 30 mL/min. The use of active vitamin D with or without bisphosphonate is effective in preventing early post-transplant bone loss. Steroid withdrawal regimen is also beneficial in preservation of bone mass in long-term. Calcimimetic is an alternative therapy to parathyroidectomy in KT recipients with persistent hyperparathyroidism. If parathyroidectomy is required, subtotal to near total parathyroidectomy is recommended. Performing parathyroidectomy during the waiting period prior to transplantation is also preferred in patients with severe hyperparathyroidism associated with hypercalcemia.

Interventions for metabolic bone disease in children with chronic kidney disease

BACKGROUND

Bone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates. This is an update of a review first published in 2010.

OBJECTIVES

This review aimed to examine the benefits (improved growth rates, reduced risk of bone fractures and deformities, reduction in PTH levels) and harms (hypercalcaemia, blood vessel calcification, deterioration in kidney function) of interventions (including vitamin D preparations and phosphate binders) for the prevention and treatment of metabolic bone disease in children with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 8 September 2015 through contact with the Trial's Search Co-ordinator using search terms relevant for this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2 to 5D.

DATA COLLECTION AND ANALYSIS

Data were assessed for study eligibility, risk of bias and extracted independently by two authors. Results were reported as risk ratios (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) was used. Statistical analyses were performed using the random-effects model.

MAIN RESULTS

This review included 18 studies (576 children); three new studies were added for this update. Adequate sequence generation and allocation concealment were reported in 12 and 11 studies respectively. Only four studies reported blinding of children, investigators or outcome assessors. Nine studies were at low risk of attrition bias and 12 studies were at low risk of selective reporting bias.Eight different interventions were compared. Two studies compared intraperitoneal (IP) with oral calcitriol. PTH levels were significantly lower with IP compared with oral calcitriol (1 study: MD -501.00 pg/mL, 95% CI -721.54 to -280.46) but the number of children with abnormal bone histology did not differ between treatments. Three studies compared intermittent with daily oral calcitriol. The change in mean height SDS (1 study: MD 0.13, 95% CI -0.22 to 0.48) and the percentage fall in parathyroid hormone (PTH) levels at eight weeks (1 study: MD -5.50%, 95% CI -32.37 to 21.37) and 12 months (1 study: MD -6.00% 95% CI -25.27 to 13.27) did not differ between treatments.Four studies compared active vitamin D preparations (calcitriol, paricalcitol, 1α-hydroxyvitamin D) with placebo or no specific treatment. One study reported vitamin D preparations significantly reduced PTH levels (-55.00 pmol/L, 95% CI -83.03 to -26.97). There was no significant difference in hypercalcaemia risk with vitamin D preparations compared with placebo or no specific treatment (4 studies, 103 children: RD 0.08 mg/dL, 95% CI -0.08 to 0.24). However, there was heterogeneity (I(2) = 55%) with one study showing a significantly greater risk of hypercalcaemia with intravenous (IV) calcitriol administration. Two studies (97 children) compared calcitriol with other vitamin D preparations and both found no significant differences in growth between preparations.Two studies compared ergocalciferol in patients with CKD and vitamin D deficiency. Elevated PTH levels developed significantly later in ergocalciferol treated children (1 study: hazard ratio 0.30, 95% CI 0.09 to 0.93) though the number with elevated PTH levels did not differ between groups (1 study, 40 children: RR 0.33, 95% CI 0.11 to 1.05).Two studies compared calcium carbonate with aluminium hydroxide as phosphate binders. One study (17 children: MD -0.86 SDS, 95% CI -2.24 to 0.52) reported no significant difference in mean final height SDS between treatments. Three studies compared sevelamer with calcium-containing phosphate binders. There were no significant differences in the final calcium, phosphorus or PTH levels between binders. More episodes of hypercalcaemia occurred with calcium-containing binders. One study reported no significant differences between calcitriol and doxercalciferol in bone histology or biochemical parameters.

AUTHORS' CONCLUSIONS

Bone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However, no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations were demonstrated. Although fewer episodes of high calcium levels occurred with the non-calcium-containing phosphate binder, sevelamer, compared with calcium-containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All studies were small with few data available on patient-centred outcomes (growth, bone deformities) and limited data on biochemical parameters or bone histology resulting in considerable imprecision of results thus limiting the applicability to the care of children with CKD.

The use of bisphosphonates in pediatrics

Bisphosphonates are widely used for the prevention and treatment of osteoporosis in adulthood. In the last years, bisphosphonates have been increasingly used in pediatric patients for the treatment of a growing number of disorders associated with osteoporosis, resistant hypercalcemia or heterotopic calcifications. The use of bisphosphonates in pediatric patients has been proven safe; however, the risk of potential severe consequences into adulthood should be kept in mind. Well-defined criteria for bisphosphonates treatment in pediatric patients are not specified, therefore an accurate selection of patients who could benefit from bisphosphonates is mandatory. A strict follow-up of pediatric patients receiving long-term bisphosphonate therapy is strongly recommended. The purpose of this mini review is to provide a summary of current knowledge on some main general aspects of the structure, mechanisms of action, pharmacokinetics, and bioavailability of bisphosphonates, and to focus on the latest advances of bisphosphonate treatment in pediatric patients. Particular attention has been paid to the common and potential adverse effects of bisphosphonate treatment, and some suggestions concerning the clinical approach and general measures for bisphosphonate treatment in pediatric patients are reported.

Mechanism and Treatment Strategy of Osteoporosis after Transplantation

Osteoporosis (OP) has emerged as a frequent and devastating complication of organ solid transplantation process. Bone loss after organ transplant is related to adverse effects of immunosuppressants on bone remodeling and bone quality. Many factors contribute to the pathogenesis of OP in transplanted patients. Many mechanisms of OP have been deeply approached. Drugs for OP can be generally divided into "bone resorption inhibitors" and "bone formation accelerators," the former hindering bone resorption by osteoclasts and the latter increasing bone formation by osteoblasts. Currently, bisphosphonates, which are bone resorption inhibitors drugs, are more commonly used clinically than others. Using the signaling pathway or implantation bone marrow stem cell provides a novel direction for the treatment of OP, especially OP after transplantation. This review addresses the mechanism of OP and its correlation with organ transplantation, lists prevention and management of bone loss in the transplant recipient, and discusses the recipients of different age and gender.

Optimization of Bone Health in Children before and after Renal Transplantation: Current Perspectives and Future Directions

The accrual of healthy bone during the critical period of childhood and adolescence sets the stage for lifelong skeletal health. However, in children with chronic kidney disease (CKD), disturbances in mineral metabolism and endocrine homeostasis begin early on, leading to alterations in bone turnover, mineralization, and volume, and impairing growth. Risk factors for CKD-mineral and bone disorder (CKD-MBD) include nutritional vitamin D deficiency, secondary hyperparathyroidism, increased fibroblast growth factor 23 (FGF-23), altered growth hormone and insulin-like growth factor-1 axis, delayed puberty, malnutrition, and metabolic acidosis. After kidney transplantation, nutritional vitamin D deficiency, persistent hyperparathyroidism, tertiary FGF-23 excess, hypophosphatemia, hypomagnesemia, immunosuppressive therapy, and alteration of sex hormones continue to impair bone health and growth. As function of the renal allograft declines over time, CKD-MBD associated changes are reactivated, further impairing bone health. Strategies to optimize bone health post-transplant include healthy diet, weight-bearing exercise, correction of vitamin D deficiency and acidosis, electrolyte abnormalities, steroid avoidance, and consideration of recombinant human growth hormone therapy. Other drug therapies have been used in adult transplant recipients, but there is insufficient evidence for use in the pediatric population at the present time. Future therapies to be explored include anti-FGF-23 antibodies, FGF-23 receptor blockers, and treatments targeting the colonic microbiota by reduction of generation of bacterial toxins and adsorption of toxic end products that affect bone mineralization.

Prevention of steroid-induced low bone mineral density in children with renal diseases: a systematic review

BACKGROUND

Children with renal diseases who are treated with glucocorticoids are at increased risk of developing osteoporosis and fractures. However, there is no common strategy for prevention of corticosteroid-induced osteoporosis. The present systematic review was performed to determine whether prevention of bone loss by calcium (Ca), vitamin D (vit D) and/or bisphosphonates is justified, safe and efficacious in children treated with steroids for various renal diseases.

METHODS

DATA SOURCES

Medline, Embase, Central were searched from 1961 up to 2012. Randomized controlled trials (RCTs) and observational studies concerning children ≤18 years with renal diseases requiring steroids were included.

RESULTS

The search strategy retrieved 2482 studies. Four RCTs including 166 patients and one observational study including 100 children met our eligibility criteria. One RCT and the observational study concerned treatment with Ca/vit D, one RCT with bisphosphonates and two RCTs with a combination of both therapies. All described a significant improvement in bone mineral density (BMD) in the treatment group compared with the control group.

CONCLUSIONS

 Ca combined with vit D is recommended to prevent bone disease in children with renal diseases treated with steroids. Because of side effects, bisphosphonates should be reserved for the treatment of severe osteoporosis when Ca and/or vit D supplementation has failed.

Management of mineral and bone disorder after kidney transplantation

PURPOSE OF REVIEW

Mineral and bone disorders (MBDs), inherent complications of moderate and advanced chronic kidney disease, occur frequently in kidney transplant recipients. However, much confusion exists about the clinical application of diagnostic tools and preventive or treatment strategies to correct bone loss or mineral disarrays in transplanted patients. We have reviewed the recent evidence about prevalence and consequences of MBD in kidney transplant recipients and examined diagnostic, preventive and therapeutic options to this end.

RECENT FINDINGS

Low turnover bone disease occurs more frequently after kidney transplantation according to bone biopsy studies. The risk of fracture is high, especially in the first several months after kidney transplantation. Alterations in minerals (calcium, phosphorus and magnesium) and biomarkers of bone metabolism (parathyroid hormone, alkaline phosphatase, vitamin D and FGF-23) are observed with varying impact on posttransplant outcomes. Calcineurin inhibitors are linked to osteoporosis, whereas steroid therapy may lead to both osteoporosis and varying degrees of osteonecrosis. Sirolimus and everolimus might have a bearing on osteoblast proliferation and differentiation or decreasing osteoclast-mediated bone resorption. Selected pharmacologic interventions for the treatment of MBD in transplant patients include steroid withdrawal, and the use of bisphosphonates, vitamin D derivatives, calcimimetics, teriparatide, calcitonin and denosumab.

SUMMARY

MBD following kidney transplantation is common and characterized by loss of bone volume and mineralization abnormalities, often leading to low turnover bone disease. Although there are no well established therapeutic approaches for management of MBD in renal transplant recipients, clinicians should continue individualizing therapy as needed.

Bone density and cortical structure after pediatric renal transplantation

The impact of renal transplantation on trabecular and cortical bone mineral density (BMD) and cortical structure is unknown. We obtained quantitative computed tomography scans of the tibia in pediatric renal transplant recipients at transplantation and 3, 6, and 12 months; 58 recipients completed at least two visits. We used more than 700 reference participants to generate Z-scores for trabecular BMD, cortical BMD, section modulus (a summary measure of cortical dimensions and strength), and muscle and fat area. At baseline, compared with reference participants, renal transplant recipients had significantly lower mean section modulus and muscle area; trabecular BMD was significantly greater than reference participants only in transplant recipients younger than 13 years. After transplantation, trabecular BMD decreased significantly in association with greater glucocorticoid exposure. Cortical BMD increased significantly in association with greater glucocorticoid exposure and greater decreases in parathyroid hormone levels. Muscle and fat area both increased significantly, but section modulus did not improve. At 12 months, transplantation associated with significantly lower section modulus and greater fat area compared with reference participants. Muscle area and cortical BMD did not differ significantly between transplant recipients and reference participants. Trabecular BMD was no longer significantly elevated in younger recipients and was low in older recipients. Pediatric renal transplant associated with persistent deficits in section modulus, despite recovery of muscle, and low trabecular BMD in older recipients. Future studies should determine the implications of these data on fracture risk and identify strategies to improve bone density and structure.

Can bisphosphonates play a role in the treatment of children with chronic kidney disease?

In patients with chronic kidney disease (CKD) renal osteodystrophy, in the form of either low- or high-turnover bone disease, is quite common. While renal transplantation is expected to reverse renal osteodystrophy, long-term treatment with glucocorticoids before and/or after transplantation may lead to osteoporosis instead. Osteoporosis is defined as a skeletal disease with low bone mineral density, microarchitectural deterioration, and concomitant fragility. In adults, bisphosphonates are widely used to treat osteoporosis and other diseases associated with excessive bone resorption. In pediatric CKD patients the efficacy and safety of these drugs have not yet been addressed adequately and thus no evidence-based recommendations regarding the optimal type of bisphosphonate, dosage, or duration of therapy are available. Furthermore, while in adults the determination of areal bone mineral density is sufficient to diagnose osteoporosis, this is not the case in children. Instead, in pediatric patients, careful morphological assessment of bone structure and formation is required. Indeed, data from studies with uremic rats indicated that bisphosphonates, via a deceleration of bone turnover, have the potential not only to aggravate pre-existing adynamic bone disease, but also to impair longitudinal growth. Thus, the widespread use of bisphosphonates in children with CKD should be discouraged until the risks and benefits have been carefully elucidated in clinical trials.

Zoledronic acid improves bone mineral density, reduces bone turnover and improves skeletal architecture over 2 years of treatment in children with secondary osteoporosis

There are limited data on the use of bisphosphonate therapy for secondary osteoporoses in childhood, and no previous reports of the use of zoledronic acid in this group. We report 20 children with a variety of underlying primary diagnoses with associated secondary osteoporosis, who were treated with 3 monthly zoledronic acid for 2 years (annualised dose 0.1mg/kg/year). There was a significant improvement in lumbar spine (by 1.88 SD±1.24 over first 12 months, p<0.001) and total bone mineral density as assessed by dual energy absorptiometry (DXA) scans, with a similar increase in bone mineral content for lean tissue mass (mean increase 1.34 SD in first 12 months, p<0.001). Bone turnover was reduced with a suppression of both osteocalcin and alkaline phosphatase in the first 12 months of treatment. Skeletal architecture was improved, with increased second metacarpal cortical thickness from 2.44mm to 2.72mm (p<0.001) and improved vertebral morphometry, with 7 patients who had vertebral wedging at baseline showing improved anterior (p=0.017) and middle (p=0.001) vertebral height ratios. Aside from well reported transient side effects with the first dose, there were no adverse effects reported. No adverse effects on anthropometric parameters were seen over the course of the study. Despite all patients having sustained fragility fractures prior to treatment, no fractures were reported during the study period. Further evidence is required to confirm efficacy, with long term follow up required to assess the impact of treatment on fracture risk.

Bioavailability and short-term tolerability of alendronate in glucocorticoid-treated children

BACKGROUND

Children receiving glucocorticoids (GCs) are at an increased risk of fragility fractures. Conservative measures may be inadequate in treating low bone mass, giving rise to fractures in this population; as such, attention has turned to the use of bisphosphonates.

OBJECTIVE

The goal of this study was to evaluate the bioavailability and single-dose tolerability of alendronate (ALN) in children receiving a stable dose of GCs.

METHODS

Children (ages 4-17 years) receiving GC treatment for their chronic illnesses received intravenous (125 μg) and oral (35 mg) ALN in a 2-period, randomized crossover study, with doses separated by at least a 7-day washout period. Urine was collected for either 8 or 24 hours after drug administration to determine urinary excretion of ALN and bioavailability. Tolerability was assessed by continuous collection of adverse events reported during the study. The main outcome measures were total urinary excretion rates, oral bioavailability of ALN, and adverse events.

RESULTS

There were 12 patients in the 4- to 11-year-old group (mean age, 8.1 years; 5 girls) and 12 patients in the 12- to 17-year-old group (mean age, 14.3 years; 5 girls). The least-squares mean bioavailability (90% CI) for children aged 4 to 11 years (n = 12) was 0.43% (0.27-0.67) and for children aged 12 to 17 years (n = 12) it was 0.39% (0.26-0.60). The least-squares mean bioavailability for all ages combined was 0.41% (0.30-0.56), with no statistical difference between the 2 age groups. The total urinary excretion of ALN after the intravenous dose was similar between groups. Fifteen patients reported a total of 36 transient clinical nonserious adverse events, all of which were mild or moderate in intensity; the most common were headache (n = 13), abdominal pain (n = 3), limb, neck, or facial pain (n = 6), and ankle or knee swelling (n = 3).

CONCLUSIONS

The mean oral bioavailability of ALN was similar to previous pharmacokinetic studies in children with osteogenesis imperfecta and slightly lower than that observed in historical adult controls. Alendronate was generally well tolerated, with minor adverse events that resolved uneventfully. Elucidation of the full adverse-effect profile of this agent was limited by the single-dose nature of this study, and robust comparisons of the pharmacokinetics of ALN in different age groups may need a larger number of patients.

Tolerance and effectiveness on pain control of Pamidronate® intravenous infusions in children with neuromuscular disorders

Osteoporosis is a common complication in children with motor impairments. They have a higher risk of fractures (20% during their lifetime) mostly at femoral level. Furthermore, these children have pain yet no clear relation has been established between osteoporosis and pain. The efficacy of bisphosphonates has been validated in adults and for children with osteogenesis imperfecta (OI). However, its use in children with motor impairments has not yet been validated.

PATIENTS AND METHODS

Retrospective study on the medical charts of children presenting neurological diseases and motor impairments associated to secondary symptomatic osteoporosis. These children underwent treatment with Pamidronate(®) intravenous infusions (I.V.) in Lyon and Valence between 2002 and 2008. Data were collected on pain control, incidence and frequency of fractures and bone mass density (BMD). Data on adverse events were also collected to evaluate treatment's tolerance.

RESULTS

Twelve children's charts were studied for a total of 50 Pamidronate(®) I.V. infusions. Regarding treatment's efficacy, we observed a clear decrease and even total relief of the pain with improvement reported after 98% of perfusions. Regarding BMD, there was a real improvement after the treatment (e.g., lumbar BMD measures, -46.5% before treatment and -27% after treatment). The adverse events, flu-like syndrome, muscle pain and asymptomatic hypocalcemia, were minor and quickly reversible.

CONCLUSION

It seems quite essential to screen for osteoporosis-related pain in these children and treat them quickly to avoid a negative impact on their quality of life. Treatment with I.V. bisphosphonates has shown its relevance, yet practical modalities still need to be defined. It would be interesting but quite difficult to implement, in light of the positive effect of this study, a prospective, randomized, controlled, double-blind vs. placebo study on a large enough sample of patients.

Efficacy and harms of nasal calcitonin in improving bone density in young patients with inflammatory bowel disease: a randomized, placebo-controlled, double-blind trial

OBJECTIVES

There are very few published studies of agents having the potential to improve bone health in children with inflammatory bowel disease (IBD). The objective of this study was to establish the efficacy and safety of intranasal calcitonin in improving bone mineral density (BMD) in young patients with IBD and to define additional factors that impact bone mineral accrual.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial in 63 participants, ages 8-21 years, with a spinal BMD Z-score ≤ -1.0 s.d. measured by dual energy X-ray absorptiometry. Subjects were randomized to 200 IU intranasal calcitonin (n=31) or placebo (n=32) daily. All received age-appropriate calcium and vitamin D supplementation. Subsequent BMD measurements were obtained at 9 and 18 months.

RESULTS

Intranasal calcitonin was well tolerated. Adverse event frequency was similar in both treatment groups, and such events were primarily minor, reversible, and limited to the upper respiratory tract. The BMD Z-score change documented at screening and 9 months and screening and 18 months did not differ between the two therapeutic arms. In participants with Crohn's disease, the spinal BMD Z-score improved between screening and 9 months (change in spine BMD Z-score (ΔZSBMD)(9-0)) in the calcitonin group (ΔZSBMD(9-0)(calcitonin)=0.21 (0.37), ΔZSBMD(9-0)(placebo)=-0.15 (0.5), P=0.02); however, this was only a secondary subgroup analysis. Bone mineral accrual rate during the trial did not lead to normalization of BMD Z-score in this cohort. Factors favoring higher bone mineral accrual rate were lower baseline BMD and higher baseline body mass index Z-score, improvement in height Z-score, higher serum albumin, hematocrit and iron concentration, and more hours of weekly weight-bearing activity. Factors associated with lower bone mineral accrual rate were more severe disease-as indicated by elevated inflammatory markers, need for surgery, hospitalization, and the use of immunomodulators-and higher daily caffeine intake.

CONCLUSIONS

Intranasal calcitonin is well tolerated but does not offer a long-term advantage in youth with IBD and decreased BMD. Bone mineral accrual rate remains compromised in youth with IBD and low BMD raising concerns for long-term bone health outcomes. Improvement in nutritional status, catch-up linear growth, control of inflammation, increase in weight-bearing activity, and lower daily caffeine intake may be helpful in restoring bone density in children with IBD and low BMD.

Approach to the child with fractures

Evaluation of the child with fractures is challenging, as no clear guidelines exist to distinguish traumatic from pathological fractures. Although most fractures in childhood are benign, recurrent fractures may be associated with a wide variety of primary skeletal diseases as well as secondary causes, necessitating a careful history and physical exam to guide the evaluation. There is no "gold standard" for the evaluation and treatment of children with fractures and low bone mineral density (BMD); therefore, the diagnosis of osteoporosis in a pediatric patient should be made using a combination of clinical and radiographic features. Interpretation of bone densitometry in growing patients presents a unique set of challenges because areal BMD measured by dual-energy x-ray absorptiometry depends on multiple dynamic variables. Interpretation of pediatric dual-energy x-ray absorptiometry should be based on Z-scores (sd scores compared to age, sex, and ethnicity-matched controls), using normative databases specific to the brand of densitometer and the patient population. Given the skeleton's ability to recover from low BMD through modeling and remodeling, optimizing management of underlying conditions leading to bone fragility is the initial step. Conservative measures including calcium and vitamin D supplementation and weight-bearing physical activity are important interventions that should not be overlooked. The use of bisphosphonates in children and adolescents is controversial due to lack of long-term efficacy and safety data and should be limited to clinical trials and compassionate therapy in children with significantly compromised quality of life. Close monitoring is required, and further study is necessary to assess their long-term safety and efficacy in children.

Bone mineral disease in children after renal transplantation in steroid-free and steroid-treated patients--a prospective study

Bone disease may persist after transplantation. Different approaches aiming to ameliorate this problem have been investigated. The aim of the study was to compare the long-term effect of three medical interventions: (i) two prophylactic oral doses of 50 mg ibandronate; (ii) daily oral dose of 0.25 μg of 1α-OHD3 (both of these regimens in patients receiving steroids), and (iii) steroid minimization immunosuppressive protocol in patients with no other specific prophylaxis.

PATIENTS

A total of 37 children, at a mean age of 13.33±3.49 yr, dialyzed for 15.93±16.7 months before transplantation, were divided into three groups, depending on medical intervention. Bone mineral content and density (BMC, BMD, DXA), serum markers of bone resorption and formation (CTX, P1NP), calcium, phosphate, 25OHD3/1.25 (OH)2D3 and PTH concentration were evaluated during two yr of follow-up. The mean values of BMD in the whole population and among the three subgroups remained within the age- and gender-matched normal range during follow-up. PATIENTS from groups II (alphacalcidiol) and III (steroid minimization) showed a significant decrease in BMD Z-scores over time, and this effect was determined with increasing age using multivariate analysis. PATIENTS receiving two doses of ibandronate maintained unchanged Z-scores for BMD and BMC over time.

Systematic review of randomized controlled trial quality in pediatric kidney transplantation

Limited pediatric-specific research can lead to sub-standard evidence for clinical decision making in children. We sought to systematically evaluate the methodological quality and the reporting standards of randomized controlled trials (RCTs) of transplantation trials in children. We included RCTs of kidney transplant recipients that had enrolled at least one child (aged 17 years or less) and that were reported in English language, peer reviewed journals from 2000 onward in the Cochrane Renal Group's specialized register. Trial reports were assessed against the 22 item checklist of the CONsolidated Standards Of Reporting Trials (CONSORT) statement. Twenty-seven RCTs were included. The reporting of the essential components of the methods, results and discussion domains was unsatisfactory. Mean CONSORT criteria score for the pediatric trials was 67% and 66% for trials including both adults and children (p value for the difference = 1.00). Trial reporting quality in pediatric transplantation trials is not different from trials involving adults. It is evident that the reporting standards of RCTs in both adult and pediatric transplantation require major improvements. This work bench-marks current standards for future quality improvement.

KDOQI US commentary on the 2009 KDIGO Clinical Practice Guideline for the Diagnosis, Evaluation, and Treatment of CKD-Mineral and Bone Disorder (CKD-MBD)

This commentary provides a US perspective on the 2009 KDIGO (Kidney Disease: Improving Global Outcomes) Clinical Practice Guideline for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). KDIGO is an independent international organization with the primary mission of the promotion, coordination, collaboration, and integration of initiatives to develop and implement clinical practice guidelines for the care of patients with kidney disease. The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI), recognizing that international guidelines need to be adapted for each country, convened a group of experts to comment on the application and implementation of the KDIGO guideline for patients with CKD in the United States. This commentary puts the KDIGO guideline into the context of the supporting evidence and the setting of care delivered in the United States and summarizes important differences between prior KDOQI guidelines and the newer KDIGO guideline. It also considers the potential impact of a new bundled payment system for dialysis clinics. The KDIGO guideline addresses the evaluation and treatment of abnormalities of CKD-MBD in adults and children with CKD stages 3-5 on long-term dialysis therapy or with a kidney transplant. Tests considered are those that relate to laboratory, bone, and cardiovascular abnormality detection and monitoring. Treatments considered are interventions to treat hyperphosphatemia, hyperparathyroidism, and bone disease in patients with CKD stages 3-5D and 1-5T. Limitations of the evidence are discussed. The lack of definitive clinical outcome trials explains why most recommendations are not of level 1 but of level 2 strength, which means weak or discretionary recommendations. Suggestions for future research highlight priority areas.

Nonimmune complications after transplantation

As posttransplant longevity has increased, nonimmune complications related to the transplant and posttransplant course have emerged as important factors in defining long-term outcomes. The incidence of, and risk factors for these complications may vary by transplanted organ based on immunosuppressive protocols and preexisting risk factors. This article discusses the relevant nonimmune complications associated with posttransplant care, with a focus on risk factors and management strategies.

Interventions for bone disease in children with chronic kidney disease

BACKGROUND

Bone disease is common in children with chronic kidney disease (CKD) and when untreated may result in bone deformities, bone pain, fractures and reduced growth rates.

OBJECTIVES

To investigate the benefits and harms of interventions for preventing and treating bone disease in children with CKD.

SEARCH STRATEGY

The Cochrane Renal Group's specialised register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts were searched without language restriction.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing different interventions used to prevent or treat bone disease in children with CKD stages 2-5D compared with placebo, no treatment or other agents were included. Studies examining different routes or frequency of treatment were also included.

DATA COLLECTION AND ANALYSIS

Data were extracted by two authors. The random-effects model was used and results were reported as risk ratios or risk differences for dichotomous outcomes and mean differences for continuous outcomes with 95% confidence intervals.

MAIN RESULTS

Fifteen RCTs (369 children) were identified. Compared with oral calcitriol, intraperitoneal calcitriol significantly reduced the level of serum parathyroid hormone (PTH) but there were no significant differences in bone histology or other biochemical measures (2 RCTs). There were no significant differences detected in growth, PTH, serum calcium or phosphorus between daily versus intermittent calcitriol (3 RCTs). Vitamin D therapy significantly reduced PTH levels compared with placebo or no treatment. The number of children with hypercalcaemia did not differ significantly between groups (4 RCTs). No significant differences were detected in growth rates, bone histology or biochemical parameters between calcitriol and either dihydrotachysterol or ergocalciferol (2 RCTs). Though fewer episodes of hypercalcaemia were reported with sevelamer, no significant differences were detected in serum calcium, phosphorus and PTH levels between calcium-containing phosphate binders and either aluminium hydroxide or sevelamer (4 RCTs).

AUTHORS' CONCLUSIONS

Bone disease, assessed by changes in PTH levels, is improved by all vitamin D preparations. However no consistent differences between routes of administration, frequencies of dosing or vitamin D preparations have been demonstrated. Though fewer episodes of high calcium levels occurred with the non calcium-containing binder, sevelamer, compared with calcium-containing binders, there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents. All RCTs were small with few data available on patient-centred outcomes (growth, bone deformities) and limited data on biochemical parameters resulting in considerable imprecision of results thus limiting the applicability to care of children with CKD.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

KDIGO clinical practice guideline for the diagnosis, evaluation, prevention, and treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD)

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the management of chronic kidney disease-mineral and bone disorder (CKD-MBD) is intended to assist the practitioner caring for adults and children with CKD stages 3-5, on chronic dialysis therapy, or with a kidney transplant. The guideline contains recommendations on evaluation and treatment for abnormalities of CKD-MBD. This disease concept of CKD-MBD is based on a prior KDIGO consensus conference. Tests considered are those that relate to the detection and monitoring of laboratory, bone, and cardiovascular abnormalities. Treatments considered are interventions to treat hyperphosphatemia, hyperparathyroidism, and bone disease in patients with CKD stages 3-5D and 1-5T. The guideline development process followed an evidence based approach and treatment recommendations are based on systematic reviews of relevant treatment trials. Recommendations for testing used evidence based on diagnostic accuracy or risk prediction and linked it indirectly with how this would be expected to achieve better outcomes for patients through better detection, evaluation or treatment of disease. Critical appraisal of the quality of the evidence and the strength of recommendations followed the GRADE approach. An ungraded statement was provided when a question did not lend itself to systematic literature review. Limitations of the evidence, especially the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Treatment of osteoporosis/osteopenia in pediatric leukemia and lymphoma

OBJECTIVE

To evaluate the efficacy and safety of various treatment options for osteopenia and osteoporosis secondary to cancer treatment in pediatric patients undergoing cancer therapy.

DATA SOURCES

A systematic search of PubMed (1949-November 2008) and International Pharmaceutical Abstracts (to November 2008) was conducted using the following search terms: osteoporosis, osteopenia, pediatrics, cancer, neoplasms, chemotherapy, bisphosphonates, calcium, vitamin D, calcitonin, and physical therapy.

STUDY SELECTION AND DATA EXTRACTION

All prospective studies that evaluated various osteoporosis treatment options in pediatric patients undergoing chemotherapy were included. Results from studies evaluating bisphosphonates and other treatments in children with osteoporosis due to other causes were also included if important safety and efficacy data were provided. Most commonly reported primary efficacy endpoints included comparisons of bone density parameters measured before and after treatment.

DATA SYNTHESIS

Four clinical studies and 2 case reports describing treatment with bisphosphonates, specifically alendronate and pamidronate, for osteoporosis or osteopenia in pediatric cancer patients were identified. Results from the trials showed that these medications were efficacious in reducing bone mineral density loss during cancer therapy and were well tolerated in this special population. Primary efficacy endpoints included improvements in Z-scores measured by dual-energy X-ray absorptiometry scans. The most commonly reported adverse effects included hypocalcemia, mild stomach upset, and infusion-related hyperpyrexia. Four additional clinical trials involving the treatment of osteoporosis or osteopenia in children and adolescents who developed bone degeneration after chronic steroid therapy are also included. In these trials, treatment options such as calcitonin, and calcium and vitamin D supplementation were also shown to be beneficial.

CONCLUSIONS

The clinical trials published to date are limited to only a few conducted in small populations of patients diagnosed with lymphoblastic leukemia or non-Hodgkin's lymphoma. However, alendronate and pamidronate both appeared to be effective options in improving bone mineral density scores with minimal adverse effects.

Clinical review 1: Bisphosphonate use in childhood osteoporosis

CONTEXT

As awareness of osteoporosis in childhood has increased, so have pressures to consider use of the pharmacological agents used to treat osteoporosis in adults. This review examines available research on the efficacy and safety of bisphosphonate therapy for pediatric osteoporosis.

EVIDENCE ACQUISITION

We reviewed the medical literature for key articles and consensus statements on the use of bisphosphonates in children through June 2008.

EVIDENCE SYNTHESIS

We compared reports using varying bisphosphonate agents, doses, and duration of therapy to treat osteogenesis imperfecta and a variety of secondary causes of osteoporosis in children. Conclusions drawn from a recently published Cochrane analysis and the consensus statements from experts in the field were considered as well.

CONCLUSIONS

Use of bisphosphonate therapy in pediatric patients remains controversial because of inadequate long-term efficacy and safety data. For this reason, many experts recommend limiting use of these agents to those children with recurrent extremity fractures, symptomatic vertebral collapse, and reduced bone mass. Current data are inadequate to support the use of bisphosphonates in children to treat reductions in bone mass/density alone. More research is needed to define appropriate indications for bisphosphonate therapy and the optimal agent, dose, and duration of use in pediatric patients.

Complications of pediatric live-donor kidney transplantation: a single center's experience in Egypt

Our objective was to study the complications of chronic renal failure (CRF) among pediatric live-donor kidney transplant recipients. Between March 1976 and December 2005, 1,785 live-donor kidney transplantations were carried out at our center. Of the recipients, 292 were 20 years old or younger (mean age 12.8 years, ranging from 4 years to 20 years). Clinical and laboratory parameters of these 292 patients were analyzed retrospectively. They were 182 boys and 110 girls. Patients who had received transplants before 1988 were treated with prednisolone and azathioprine as combined therapy. From 1988 to 1998, a triple regimen comprising prednisolone, azathioprine and cyclosporine A (CsA) was administered. Tacrolimus and mycophenolate mofetil (MMF) were introduced as primary therapy in 1998. Growth, anemia, infections, and surgical, cardiac, neurologic, bone and other medical complications were assessed. Triple-drug immunosuppression (prednisone + CsA + azathioprine) was used in 68.2% of transplants. Acute rejection rate was 47.6%; chronic rejection rate was 31%. Hypertension (62%) was the commonest complication. Anemia was diagnosed in 61%. A substantial proportion of patients (48%) were short, with height standard deviation scores (SDSs) of less than -1.88. The overall infection rate was high, and the majority (54%) was bacterial. Malignancy was diagnosed in eight (3%) patients. The incidence of urological complications was 14%, and that of vascular complications was 1%. Cardiac complications included left ventricular hypertrophy (LVH) in 47.9% of patients, left atrial enlargement (31.5%) and left ventricular dilatation and systolic dysfunction (13.7% for each). Neuropathic changes were found in 19% of our cases, with the distal muscles of lower limbs more affected. Other complications included avascular bone necrosis in 8% (all of them in the hip joint) and bone loss in 60% of patients. We concluded that, despite the long-term success of pediatric renal transplantation in a developing country, there is a risk of significant morbidity.

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.

Interventions for preventing bone disease in kidney transplant recipients

BACKGROUND

Patients with chronic kidney disease have significant abnormalities of bone remodeling and mineral homeostasis and are at increased risk of fracture. The fracture risk for a kidney transplant recipient is four times that of the general population and higher than for a patient on dialysis. Randomised controlled trials (RCTs) report the use of bisphosphonates, vitamin D sterols, calcitonin, and hormone replacement therapy to treat bone disease following transplantation.

OBJECTIVES

To evaluate the use of interventions for treating bone disease following kidney transplantation.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library), Cochrane Renal Group's specialised register, MEDLINE, EMBASE, reference lists, and conference proceedings abstracts without language restriction. Date of last search: May 2006

SELECTION CRITERIA

RCTs and quasi-RCTs comparing different treatments for kidney transplant recipients of any age were selected. We excluded all other transplant recipients, including kidney-pancreas transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) with 95% confidence intervals (CI) for dichotomous variables and mean difference (MD) for continuous outcomes.

MAIN RESULTS

Twenty-four trials (1,299 patients) were included. No individual intervention (bisphosphonates, vitamin D sterol or calcitonin) was associated with a reduction in fracture risk compared with placebo. Combining results for all active interventions against placebo demonstrated any treatment of bone disease was associated with a reduction in the RR of fracture (RR 0.51, 95% CI 0.27 to 0.99). Bisphosphonates (any route), vitamin D sterol, and calcitonin all had a beneficial effect on the bone mineral density at the lumbar spine. Bisphosphonates and vitamin D sterol also had a beneficial effect on the bone mineral density at the femoral neck. Bisphosphonates had greater efficacy for preventing bone mineral density loss when compared head-to-head with vitamin D sterols. Few or no data were available for combined hormone replacement, testosterone, selective oestrogen receptor modulators, fluoride or anabolic steroids. Other outcomes including all-cause mortality and drug-related toxicity were reported infrequently.

AUTHORS' CONCLUSIONS

Treatment with a bisphosphonate, vitamin D sterol or calcitonin after kidney transplantation may protect against immunosuppression-induced reductions in bone mineral density and prevent fracture. Adequately powered trials are required to determine whether bisphosphonates are better than vitamin D sterols for fracture prevention in this population. The optimal route, timing, and duration of administration of these interventions remains unknown.

Therapy Insight: orthopedic complications after solid organ transplantation in childhood

Several factors, such as immobilization, metabolic bone disease and immunosuppressive drugs, can compromise the quality of bone in children who have undergone solid organ transplantation. In contrast to adults, decreased bone mineral density has been reported in only a small proportion of pediatric transplant patients, and the relationship between low bone mineral density and fracture risk has not been established in children. Nevertheless, fractures, scoliosis, and joint and spinal degeneration are common in patients who received solid organ grafts as children. Avascular bone necrosis occurs infrequently in this patient population. Future studies should evaluate the effects of the underlying disease, transplantation and immunosuppression on the metabolism of bone and cartilage. On the basis of our own clinical experience and literature review, the growing spine of children who have received transplants should be continuously evaluated, and follow-up of bone mineral density is indicated. By contrast, routine MRI of the joints seems unnecessary.

Open Issues in Anorexia Nervosa: Prevention and Therapy of Bone Loss

Anorexia nervosa and diet-induced amenorrhea have an important impact not only on gynecological health but also on bone mass, especially if the disease is not promptly recognized and treated. This is particularly important because these conditions usually arise in adolescence, when peak bone mass is normally achieved. In this article we discuss the therapeutic issues related to bone loss associated with eating disorders.

Calcium supplementation for improving bone mineral density in children

BACKGROUND

Clinical trials have shown that calcium supplementation in children can increase bone mineral density (BMD) although this effect may not be maintained. There has been no quantitative systematic review of this intervention.

OBJECTIVES

. To determine the effectiveness of calcium supplementation for improving BMD in children. . To determine if any effect varies by sex, pubertal stage, ethnicity or level of physical activity, and if any effect persists after supplementation is ceased.

SEARCH STRATEGY

We searched CENTRAL, (Cochrane Central Register of Controlled Trials) (Issue 3, 2005), MEDLINE (1966 to 1 April 2005), EMBASE (1980 to 1 April 2005), CINAHL (1982 to 1 April 2005), AMED (1985 to 1 April 2005), MANTIS (1880 to 1 April 2005) ISI Web of Science (1945 to 1 April 2005), Food Science and Technology Abstracts (1969 to 1 April 2005) and Human Nutrition (1982 to 1 April 2005). Conference abstract books (Osteoporosis International, Journal of Bone and Mineral Research) were hand-searched.

SELECTION CRITERIA

Randomised controlled trials of calcium supplementation (including by food sources) compared with placebo, with a treatment period of at least 3 months in children without co-existent medical conditions affecting bone metabolism. Outcomes had to include areal or volumetric BMD, bone mineral content (BMC), or in the case of studies using quantitative ultrasound, broadband ultrasound attenuation and ultrasonic speed of sound, measured after at least 6 months of follow-up.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data including adverse events. We contacted study authors for additional information.

MAIN RESULTS

The 19 trials included 2859 participants, of which 1367 were randomised to supplementation and 1426 to placebo. There was no heterogeneity in the results of the main effects analyses to suggest that the studies were not comparable. There was no effect of calcium supplementation on femoral neck or lumbar spine BMD. There was a small effect on total body BMC (standardised mean difference (SMD) +0.14, 95% CI+0.01, +0.27) and upper limb BMD (SMD +0.14, 95%CI +0.04, +0.24). Only the effect in the upper limb persisted after supplementation ceased (SMD+0.14, 95%CI+0.01, +0.28). This effect is approximately equivalent to a 1.7% greater increase in supplemented groups, which at best would reduce absolute fracture risk in children by 0.1-0.2%per annum. There was no evidence of effect modification by baseline calcium intake, sex, ethnicity, physical activity or pubertal stage. Adverse events were reported infrequently and were minor.

AUTHORS' CONCLUSIONS

While there is a small effect of calcium supplementation in the upper limb, the increase in BMD which results is unlikely to result in a clinically significant decrease in fracture risk. The results do not support the use of calcium supplementation in healthy children as a public health intervention. These results cannot be extrapolated to children with medical conditions affecting bone metabolism.

How to manage osteoporosis in children

Osteoporosis is increasingly being seen in young people. The primitive forms are relatively rare, but the secondary forms--particularly in long-term corticosteroid therapy--are a relevant problem given the much longer survival in chronic diseases such as cystic fibrosis, chronic renal insufficiency, leukaemia, and Duchenne muscular dystrophy. Controlled, prospective studies to evaluate the results of prevention and therapy in children are still lacking. The basis of therapy is the correct daily intake of calcium and the use of vitamin D (or active metabolites). This helps the growing skeleton to restore its equilibrium in many cases. Restraining the long-term use of corticosteroids to the minimum effective dose and shorter duration is essential. In severe cases, particularly in the presence of fractures, bisphosphonates can be remarkably effective. In some cases, such as idiopathic juvenile osteoporosis, the rule is spontaneous resolution, and the advisability of an aggressive drug therapy is discussed.

Metabolic Bone Disease in Children

Metabolic bone disease in children includes many hereditary and acquired conditions of diverse etiology that lead to disturbed metabolism of the bone tissue. Some of these processes primarily affect bone; others are secondary to nutritional deficiencies, a variety of chronic disorders, and/or treatment with some drugs. Some of these disorders are rare, but some present public health concerns (for instance, rickets) that have been well known for many years but still persist. The most important clinical consequences of bone metabolic diseases in the pediatric population include reduced linear growth, bone deformations, and non-traumatic fractures leading to bone pain, deterioration of motor development and disability. In this article, we analyze primary and secondary osteoporosis, rickets, osteomalacia (nutritional and hereditary vitamin D-dependent, hypophosphatemic and that due to renal tubular abnormalities), renal osteodystrophy, sclerosing bony disorders, and some genetic bone diseases (hypophosphatasia, fibrous dysplasia, skeletal dysplasia, juvenile Paget disease, familial expansile osteolysis, and osteoporosis pseudoglioma syndrome). Early identification and treatment of potential risk factors is essential for skeletal health in adulthood. In most conditions it is necessary to ensure an appropriate diet, with calcium and vitamin D, and an adequate amount of physical activity as a means of prevention. In secondary bone diseases, treatment of the primary disorder is crucial. Most genetic disorders await prospective gene therapies, while bone marrow transplantation has been attempted in other disorders. At present, affected patients are treated symptomatically, frequently by interdisciplinary teams. The role of exercise and pharmacologic therapy with calcium, vitamin D, phosphate, bisphosphonates, calcitonin, sex hormones, growth hormone, and thiazides is discussed. The perspectives on future therapy with insulin-like growth factor-1, new analogs of vitamin D, strontium, osteoprotegerin, and calcimimetics are presented.