Alendronate increases bone mineral density in long-term renal transplant recipients

Impact of bisphosphonate treatment on bone mineral density after kidney transplant

BACKGROUND

Mineral bone disease is associated with chronic kidney disease and persists after kidney transplantation. Immunosuppressive treatment contributes to the pathogenesis of this disease. Bisphosphonate treatments have shown positive but indefinite results.

AIM

To evaluate the effectiveness and safety of bisphosphonate treatment on post kidney transplantation bone mineral density (BMD).

METHODS

We included kidney transplant recipients (KTRs) whose BMD was measured after the operation but before the initiation of treatment and their BMD was measured at least one year later. We also evaluated the BMD of KTRs using two valid measurements after transplantation who received no treatment (control group).

RESULTS

Out of 254 KTRs, 62 (39 men) were included in the study. Bisphosphonates were initiated in 35 KTRs in total (20 men), 1.1 ± 2.4 years after operation and for a period of 3.9 ± 2.3 years while 27 (19 men) received no treatment. BMD improved significantly in KTRs who received bisphosphonate treatments (from -2.29 ± 1.07 to -1.66 ± 1.09, P < 0.0001). The control group showed a non-significant decrease in BMD after 4.2 ± 1.4 years of follow-up after surgery. Kidney function was not affected by bisphosphonate treatment. In KTRs with established osteoporosis, active treatment had a similar and significant effect on those with osteopenia or normal bone mass.

CONCLUSION

In this retrospective study of KTRs receiving bisphosphonate treatment, we showed that active treatment is effective in preventing bone loss irrespective of baseline BMD.

Efficacy and safety of medications for osteoporosis in kidney transplant recipients or patients with chronic kidney disease: A meta-analysis

This study conducted a meta-analysis to analyze the efficacy and safety of osteoporosis medications in kidney transplant recipients and patients with chronic kidney disease (CKD). PubMed, Embase, the Cochrane Central Register of Controlled Trials were searched from the date of their inception through October 21, 2022. We performed a meta-analysis of the efficacy and safety of osteoporosis medications in adult patients with stage 3-5 CKD or kidney transplant recipients enrolled in randomized clinical trials (RCTs). We calculated the standard mean deviations with 95% confidence intervals (CI) for bone mineral density (BMD) and T scores after 6 and 12 months treatment, pooled odds ratio and 95% CI for fracture risk, and summarized adverse events. The inclusion criteria were met by 27 studies. Out of this, 19 studies were included for the meta-analysis. In stage 3-4 CKD patients, alendronate increased lumbar spine BMD. In patients at stage 5 CKD and undergoing hemodialysis, alendronate and raloxifene increased lumbar spine BMD. After 6 months, the BMD of kidney transplant recipients was seen to be significantly increased; however, there was no difference after 12 months, and the risk of fracture did not reduce. Thus, there is no evidence that these medications reduce the risk of fracture, and their effect on BMD and fracture remains unproven. These medications may increase the incidence of adverse events and their safety needs to be further evaluated. Therefore, we cannot draw a definitive conclusion about the efficacy and safety of osteoporosis medications in the above group of patients.

The Impact of Cholecaciferol Supplementation on Bone Mineral Density in Long-Term Kidney Transplant Recipients

Although reduced bone mineral density (BMD) is associated with a higher risk of fractures, morbidity, and mortality in kidney transplant patients (KTRs), there is no consensus on optimal treatment for the alterations of BMD in this population. This study aims at assessing the effect of cholecalciferol supplementation on BMD over a follow-up period of 2 years in a cohort of long-term KTRs. Patients with age ≥ 18 years were included and divided into two subgroups based on treatment with bisphosphonate and/or calcimimetics and/or active vitamin D sterols (KTRs-treated) or never treated with the above medications (KTRs-free). BMD was evaluated at lumbar vertebral bodies (LV) and right femoral neck (FN) with standard DEXA at the beginning and end of the study. According to World Health Organization (WHO) criteria, results were expressed as T-score and Z-score. Osteoporosis and osteopenia were defined as T score ≤ −2.5 SD and T score < −1 and >−2.5 SD, respectively. Cholecalciferol was supplemented at a dose of 25,000 IU/week over 12 weeks followed by 1500 IU/day. KTRs-free (n. 69) and KTRs-treated (n. 49) consecutive outpatients entered the study. KTRs-free were younger (p < 0.05), with a lower prevalence of diabetes (p < 0.05) and of osteopenia at FN (46.3 % vs. 61.2 %) compared to KTRs-treated. At the entry none of the study subjects had a sufficient level of cholecalciferol; Z-score and T-score at LV and FN were not different between groups. At the end of the study period, serum cholecalciferol concentration was significantly increased in both groups (p < 0.001); the KTRs-free group presented an improvement in both T-score and Z-score at LV (p < 0.05) as well as a lower prevalence of osteoporotic cases (21.7% vs. 15.9%); in contrast, no changes were recorded in KTR-treated individuals. In conclusion, supplementation with cholecalciferol ameliorated Z-score and T-score at LV in long-term KTRs who had been never treated with active or inactive vitamin D sterols, bisphosphonates, and calcimimetics. Future endeavours are needed to confirm these preliminary findings.

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.

Bone disease following solid organ transplantation: A narrative review and recommendations for management from The European Calcified Tissue Society

INTRODUCTION

Solid organ transplantation is an established therapy for end-stage organ failure. Both pre-transplantation bone disease and immunosuppressive regimens result in rapid bone loss and increased fracture rates.

METHODS

The European Calcified Tissue Society (ECTS) formed a working group to perform a systematic review of existing literature on the consequences of end-stage kidney, liver, heart, and lung disease on bone health. Moreover, we assessed the characteristics of post-transplant bone disease and the skeletal effects of immunosuppressive agents and aimed to provide recommendations for the prevention and treatment of transplantation-related osteoporosis.

RESULTS

Characteristics of bone disease may differ depending on the organ that fails, but patients awaiting solid organ transplantation frequently depict a wide spectrum of bone and mineral abnormalities. Common features are a decreased bone mass and impaired bone strength with consequent high fracture risk, all of which are aggravated in the early post-transplantation period.

CONCLUSION

Both the underlying disease leading to end-stage organ failure and the immunosuppression regimens implemented after successful organ transplantation have detrimental effects on bone mass, quality and strength. Given existing ample data confirming the high frequency of bone disease in patients awaiting solid organ transplantation, we recommend that all transplant candidates should be assessed for osteoporosis and fracture risk and, if indicated, treated before and after transplantation. Since bone loss in the early post-transplantation period occurs in virtually all solid organ recipients and is associated with glucocorticoid administration, the goal should be to use the lowest possible dose and to taper and withdraw glucocorticoids as early as possible.

Effect of Bisphosphonates on Bone Health in Adult Renal Transplant Patients: Beyond the First Year Posttransplant-A Systematic Review and Meta-Analysis

Background:

Bone mineral density (BMD) decreases postrenal transplantation. Evidence demonstrating the effects of bisphosphonates on BMD and fracture risk beyond 1-year posttransplant is sparse in existing literature, but remains essential to enhance clinical outcomes in this population.

Objective:

Our study aimed to systematically review and meta-analyze the current literature on the use of any bisphosphonate in the adult renal transplant population beyond the first year of renal transplant to determine its effect on BMD and fracture incidence.

Design:

We conducted a systematic review and meta-analysis of primary research literature that included full-text, English-language, original randomized clinical trials (RCTs) and observational studies.

Setting:

Patient data were primarily captured in an outpatient setting across various studies.

Patients:

Our population of interest was patients older than 18 years who received deceased/living donor kidney transplantation and any bisphosphonate with a follow-up greater than 12 months posttransplantation.

Measurements:

The primary outcome was change in BMD from baseline. Secondary outcomes were the incidence of fractures and effects of other confounders on bone health.

Methods:

We included RCTs and observational studies that satisfied our inclusion criteria. Each study was analyzed for risk of bias and data were extrapolated to analyze for overall statistical significance accounting for heterogeneity of studies.

Results:

Sixteen studies (N = 1762) were analyzed. The follow-up ranged from 12 to 98 months. There was a nonsignificant improvement in BMD with bisphosphonate treatment persisting into the second and third years posttransplant at the lumbar spine. The calculated standardized mean BMD difference was −0.29 (−0.75 to 0.17), P = .22. Only 5 studies reported a total of 43 new fractures. Prednisone (P < .01), low body weight (P < .001), low body mass index (P < .01), and male gender (P < .05) correlated with reduced lumbar and femoral BMD.

Limitations:

Limitations of this review include the use of BMD as a surrogate outcome, the bias of the included studies, and the incomplete reporting data in numerous analyzed studies.

Conclusions:

We demonstrate no statistically significant benefit of bisphosphonate treatment on BMD beyond the first year postrenal transplantation. Despite heterogeneity of treatment, a differential nonsignificant improvement in lumbar spine BMD was consistent and may be clinically relevant.

Trial Registration:

PROSPERO CRD42019125593

Outcomes of bisphosphonate and its supplements for bone loss in kidney transplant recipients: a systematic review and network meta-analysis

BACKGROUND

Mineral bone disease constitutes a common complication of post-kidney transplantation, leading to great disability. As there is no consensus on the optimal treatment for post-kidney transplant recipients (KTRs), we aimed to evaluate the efficacy and safety of bisphosphonate and its combined therapies.

METHODS

We incorporated relevant trials to perform a network meta-analysis from direct and indirect comparisons. We searched PubMed, Embase and the CENTRAL and the reference lists of relevant articles up to August 1, 2017, for randomized controlled trials. The primary outcome was bone mineral density (BMD) change at the femoral neck and the lumbar spine.

RESULTS

From a total of 864 citations, 18 randomized controlled trials with a total of 1200 participants were included. Five different regimens were considered. Bisphosphonate plus calcium revealed a significant gain in percent BMD change than calcium alone at the femoral neck (mean difference (MD), 5.83; 95% credible interval (CrI), 1.61 to 9.27). No significant difference was detected when restricting to absolute terms. At the lumbar spine, bisphosphonate and calcium with or without vitamin D analogs outperformed calcium solely (MD, 0.07; 95% CrI, 0.00 to 0.13; MD, 0.06; 95% CrI, 0.02 to 0.09). Compared to calcium with vitamin D analogs, adding bisphosphonate was associated with marked improvement (MD, 0.03; 95% CrI, 0.00 to 0.05). Considering percent terms, combination of bisphosphonate with calcium and vitamin D analogs showed greater beneficial effects than calcium alone or with either vitamin D analogs or calcitonin (MD, 10.51; 95% CrI, 5.92 to 15.34; MD, 5.48; 95% CrI, 2.57 to 8.42; MD, 6.39; 95% CrI, 0.55 to 12.89). Both bisphosphonate and vitamin D analogs combined with calcium displayed a notable improvement compared to calcium alone (MD, 7.24; 95% CrI, 3.73 to 10.69; MD, 5.02; 95% CrI, 1.20 to 8.84).

CONCLUSIONS

Our study suggested that additional use of bisphosphonate was well-tolerated and more favorable in KTRs to improve BMD.

Efficacy and Safety of Different Bisphosphonates for Bone Loss Prevention in Kidney Transplant Recipients: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Mineral and bone disorder is one of the severe complications in kidney transplant recipients (KTRs). Previous studies showed that bisphosphonates had favorable effects on bone mineral density (BMD). We sought to compare different bisphosphonate regimens and rank their strategies.

METHODS

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to April 01, 2017, for randomized controlled trials (RCTs) comparing bisphosphonate treatments in adult KTRs. The primary outcome was BMD change. We executed the tool recommended by the Cochrane Collaboration to evaluate the risk of bias. We performed pairwise meta-analyses using random effects models and network meta-analysis (NMA) using Bayesian models and assessed the quality of evidence.

RESULTS

A total of 21 RCTs (1332 participants) comparing 6 bisphosphonate regimens were included. All bisphosphonates showed a significantly increased percentage change in BMD at the lumbar spine compared to calcium except clodronate. Pamidronate with calcium and Vitamin D analogs showed improved BMD in comparison to clodronate with calcium (mean difference [MD], 9.84; 95% credibility interval [CrI], 1.06-19.70). The combination of calcium and Vitamin D analogs had a significantly lower influence than adding either pamidronate or alendronate (MD, 6.34; 95% CrI, 2.59-11.01 and MD, 6.16; 95% CrI, 0.54-13.24, respectively). In terms of percentage BMD change at the femoral neck, both pamidronate and ibandronate combined with calcium demonstrated a remarkable gain compared with calcium (MD, 7.02; 95% CrI, 0.30-13.29 and MD, 7.30; 95% CrI, 0.32-14.22, respectively). The combination of ibandronate with calcium displayed a significant increase in absolute BMD compared to any other treatments and was ranked best.

CONCLUSIONS

Our NMA suggested that new-generation bisphosphonates such as ibandronate were more favorable in KTRs to improve BMD. However, the conclusion should be treated with caution due to indirect comparisons.

Vitamin D Treatment Effect on Serum Endocan and High-Sensitivity C-Reactive Protein Levels in Renal Transplant Patients

Context:

Endocan is a marker showing endothelial dysfunction and inflammation. Significantly increased endocan levels have been observed in serum of patients with sepsis and cancer.

Objective:

Our aim was to investigate the relationship between vitamin D treatment and serum endocan and high-sensitivity C-reactive protein (hs-CRP) levels as inflammatory markers in transplant patients.

Design:

Prospective.

Setting:

Nephrology clinic.

Patients:

Thirty-eight renal transplant patients with serum 25-hydroxy-vitamin D (25-OH-vitamin D) levels below 20 ng/mL and transplanted at least 12 months.

Intervention:

One-time oral dose of 300 000 IU vitamin D3.

Main Outcome Measures:

Before and after vitamin D treatment, serum endocan, hs-CRP, calcium, phosphorus, and parathyroid hormone (PTH) levels were measured.

Results:

Median serum endocan and PTH values before vitamin D were significantly higher than those of after treatment values ( P = .001 and P < .001, respectively). On the other hand, serum total calcium and phosphorus levels before vitamin D treatment were lower than the values obtained after vitamin D treatment ( P = .0013 and P < .001, respectively). Serum hs-CRP was lower after vitamin D therapy than before, but the difference was not statistically significant ( P = .06). A moderate negative correlation was determined between endocan and 25-OH-vitamin D levels after treatment with vitamin D ( r = −.36, P = .02).

Conclusion:

This study has revealed that vitamin D treatment reduced markers of endothelial dysfunction in patients with renal transplantation and vitamin D deficiency.

Outcomes of bisphosphonate therapy in kidney transplant recipients: a systematic review and meta-analysis

Mineral and bone disorders that precede kidney transplantation are exacerbated in the post-transplant setting by tertiary hyperparathyroidism and immunosuppressive regimens. Bone mineral density (BMD) decreases following transplantation, leading to increased fracture risk. The effect of bisphosphonates on fracture is unknown. The aim of this study was to update estimates of change in BMD and fracture rates in bisphosphonate-treated kidney transplant recipients through meta-analysis. Studies comparing bisphosphonate therapy to standard of care were included if follow-up duration was more than 6 months. We performed random-effects meta-analysis to determine the effect of bisphosphonates on lumbar spine and femoral neck BMD and fracture rates. Bisphosphonates improved femoral neck and lumbar spine BMD compared with controls (0.055 g/cm(2) , 95% CI 0.012-0.099 and 0.053 g/cm(2) , 95% CI 0.032-0.074, respectively) without adversely affecting serum creatinine or calcium. This corresponded to an unweighted improvement in BMD of 6.0% and 7.4%, respectively. There was no difference in fracture incidence in the two groups. Bisphosphonate therapy in kidney transplant recipients is associated with a statistically significant improvement in BMD at the lumbar spine and femoral neck. There was no difference in fracture incidence. Bisphosphonates did not adversely affect allograft dysfunction or serum calcium levels.

Bisphosphonates for prevention of osteopenia in kidney-transplant recipients: a systematic review of randomized controlled trials

We conducted a systematic review of randomized controlled trials (RCTs) of bisphosphonates for the prevention of osteopenia in kidney-transplant recipients. Bisphosphonates improved bone mineral density at the lumbar spine and femoral neck after 12 months. However, additional well-designed RCTs are required to determine the optimal treatment strategy. Osteopenic-osteoporotic syndrome is a bone complication of renal transplantation. Bisphosphonates, calcitonin, and vitamin D analogs may be used to prevent or treat osteoporosis or bone loss after renal transplantation. However, there is currently no widely recognized strategy for the prevention of corticosteroid-induced osteoporosis. This study aims to assess the available evidence to guide the targeted use of bisphosphonates for reducing osteoporosis and bone loss in renal-transplant recipients. We searched the Cochrane Central Register of Controlled Trials, PubMed, and EMBASE for randomized controlled trials of bisphosphonates for osteoporosis or bone loss after renal transplantation. A total of 352 abstracts were identified, of which 55 were considered for evaluation and 9 were included in the final analysis. The primary outcome measure was change in the bone mineral density (BMD) of the lumbar spine and femoral neck after 12 months. Data extraction was performed independently by two investigators. BMD at the lumbar spine was improved after treatment with bisphosphonates [9 trials; 418 patients; weighted mean difference (WMD), 0.61; 95 % confidence interval (CI), 0.16-1.06]. Eight trials (406 patients) that reported changes in BMD at the femoral neck also showed improved outcomes after treatment with bisphosphonates (WMD, 0.06; 95 % CI, 0.03-0.09). Bisphosphonates improve BMD at the lumbar spine and femoral neck after 12 months in renal-transplant recipients.

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.

Ibandronate in stable renal transplant recipients with low bone mineral density on long-term follow-up

BACKGROUND

Bone mineral density (BMD) has been reported to increase without specific treatment in long-term renal transplant recipients. The aim of this study was to evaluate the effect of ibandronate on BMD and kidney function in long-term renal transplant recipients as compared to a control group. Furthermore, we searched for a gender-specific treatment effect of ibandronate on BMD.

METHODS

In a retrospective, matched case-control study 60 stable renal transplant recipients were included on long-term follow-up. The patient cohort was divided into two groups. The control group (n = 30) comprised patients with close-to-normal bone mineral density who did not receive ibandronate treatment and the treatment group (n = 30) comprised patients with reduced bone mineral density who received ibandronate treatment. The groups were matched for sex, age at the time of renal transplantation, use of steroids, renal transplant function and time lag between the dual-energy X-ray absorptiometry (DEXA) measurements and renal transplantation. Patients of the treatment group were treated with 12.0 ± 6.7 g ibandronate. Treatment cycles lasted 19.3 ± 11.0 months. The first bone mineral density testing was performed 55.3 ± 60.2 months after renal transplantation followed by a second measurement 26.8 ± 12.1 months later.

RESULTS

Both groups did not differ in absolute (g/cm(2)) or relative (%) changes in BMD at the lumbar spine (0.033 ± 0.079 vs. 0.055 ± 0.066 g/cm(2), p = 0.217 and 3.6 ± 7.8 vs. 6.4 ± 8.1 %, p = 0.124) or femoral neck (0.013 ± 0.106 vs. 0.025 ± 0.077 g/cm(2), p = 0.647 and 3.2 ± 13.6 vs. 5.0 ± 13.1 %, p = 0.544) over the study period. There was no correlation of ibandronate dosages with changes in BMD (LS: r = -0.089; p = 0.639 and FN: r =+0.288; p = 0.445). We could neither determine a negative effect of ibandronate on renal transplant function over the study period, estimated via the CKD-EPI formula (-2.9 ± 7.6 vs. -2.7 ± 10.6 mL/min/1.73 m(2), p = 0.900) nor a gender-specific action of ibandronate on bone mass changes.

CONCLUSIONS

Ibandronate treatment was safe with respect to renal transplant function but did not result in a significant additive improvement in bone mineral density as compared to the untreated control group. A gender-specific action of ibandronate on BMD at the LS or FN could not be determined either.

Bisphosphonates for preventing bone disease in kidney transplant recipients: a meta-analysis of randomized controlled trials

An estimated 60% of kidney transplant recipients have mineral bone disease and about 0.5% break their hip within the first year after transplantation. We conducted a systematic review of benefits and harms of bisphosphonates in kidney transplant recipients. We searched CENTRAL (Issue 5, 2015) for randomized controlled trials in all languages and screened the reference list of an earlier Cochrane review. One reviewer identified the trials, extracted all data, and assessed risk of bias. Meta-analysis used a random effects model, with results expressed as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI). Bisphosphonates have uncertain effects on death (RR 0.45, CI 0.04-4.69) and vertebral fractures (RR 0.58, CI 0.24-1.43, I(2) 0%). Bisphosphonates moderately to importantly reduce the loss of vertebral bone mineral density (MD 5.98%, CI 3.77-8.18% change from baseline in g calcium/cm² at 12 months, I(2) 91%) and femoral bone mineral density (MD 5.57%, 3.12-8.01% change from baseline in g calcium/cm² at 12 months, I(2) 69%). At this stage, insufficient evidence exists to support routine use of bisphosphonates to reduce fracture risk after kidney transplantation. Data on important health outcomes are lacking, surrogate outcomes poorly reflect bone quality in kidney transplant recipients, and serious adverse events are not studied and reported systematically.

Impact of vitamin D, bisphosphonate, and combination therapy on bone mineral density in kidney transplant patients

BACKGROUND

Osteoporosis can develop and become aggravated in kidney transplant patients; however, the best preventive options for post-transplantation osteoporosis remain controversial.

METHODS

We retrospectively analyzed cohort of 182 renal transplant recipients of mean age 46.7 ± 12.1 years including 47.3% women. Seventy-three patients received neither vitamin D nor bisphosphonate after transplantation (group 1). The other patients were classified into the following 3 groups: calcium plus vitamin D (group 2; n = 40); bisphosphonate (group 3; n = 18); and both regimens (group 4; n = 51). Bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry at baseline and at 1 year after transplantation.

RESULTS

At 1 year after transplantation, T-scores of the femoral neck and entire femur were significantly decreased in group 1 (-0.23 ± 0.65 [P = .004] and -0.21 ± 0.74 [P = .018], respectively), whereas the lumbar spine was significantly increased in group 4 (0.27 ± 0.79; P = .020). Post hoc analysis demonstrated that the delta T-score was significantly lower in group 1 than in group 4 (P = .009, 0.035, and 0.031 for lumbar spine, femoral neck, and entire femur, respectively). In a multivariate analysis adjusted by age, sex, body mass index, dialysis duration, diabetes, calcineurin inhibitors, estimated glomerular filtration rate, and persistent hyperparathyroidism, both group 2 and group 4 showed protective effects on BMD reduction (odds ratio [OR], 0.165; 95% confidence interval [CI] 0.032-0.845 [P = .031]; and OR, 0.169; 95% CI, 0.045-0.626 [P = .008]; respectively). However, group 3 did not show a protective effect (OR, 0.777; 95% CI, 0.198-3.054; P = .718), because their incidence of persistent hyperparathyroidism after transplantation was significantly higher (50.0%) than the other groups (P < .001). The incidence of bone fractures did not differ among the groups.

CONCLUSIONS

Combination therapy with vitamin D and bisphosphonate was the most effective regimen to improve BMD among kidney recipients.

Renale osteodystrophie

The incidence of renal osteodystrophy (ROD) increases with deteriorating kidney function, affecting virtually every patient on chronic dialysis treatment. ROD can persist after kidney transplantation and may be aggravated by immunosuppressants, mainly glucocorticoids. Fracture risk, including hip fractures, is markedly elevated in patients with renal disease compared to the general population. Depending on the type of ROD, high or low bone turnover can be found. Because of poor positive and negative predictive values of serological markers of bone turnover and limited technical capabilities of various bone imaging modalities, the only reliable method to correctly classify ROD is the transiliac bone biopsy. Elevated bone turnover can be successfully treated with active vitamin D, cinacalcet, or parathyreoidectomy, but all of these therapies may lead to oversuppression of bone metabolism. Currently, no specific therapy is available for low turnover bone disease. Bisphosphonates can be a therapeutic option for selected patients after renal transplantation.

Oral alendronate can suppress bone turnover but not fracture in kidney transplantation recipients with hyperparathyroidism and chronic kidney disease

Post-transplantation bone diseases negatively affect the quality of life of solid organ recipients. Secondary or tertiary hyperparathyroidism is a frequent complication in kidney transplantation (KTx) recipients. Treatment with immunosuppressive agents including glucocorticoids can lead to deterioration in bone metabolism in these patients. In the present study, we explored the effects of a three-year treatment period with oral alendronate (ALN) in long-term KTx recipients. Post-KTx recipients were recruited (n = 24, M/F = 12/12, mean age 52.0 ± 7.8 years) into this study. All patients were prescribed methylprednisolone (4.07 ± 0.86 mg/day) with various immunosuppressive agents. Before treatment with oral ALN (35 mg/week), the mean concentrations of intact parathyroid hormone (iPTH) and 25-hydroxyvitamin D were 139.2 ± 71.4 pg/mL and 20.8 ± 4.1 ng/mL, respectively. After 36 months of ALN treatment, mean iPTH levels increased slightly (+20.9 %). Treatment with ALN reduced bone-specific alkaline phosphatase (-35.4 %), serum type I collagen N-terminal telopeptide (-31.2 %) and osteocalcin (-55.6 %) levels. ALN did not increase bone mass after 24 months. Four patients with the highest baseline iPTH levels suffered a clinical osteoporotic fracture during the 36-month ALN treatment period. Higher iPTH levels with chronic kidney disease (CKD) at baseline were associated with the incidence of new clinical fractures during ALN treatment. In conclusion, anti-resorptive therapy with ALN can suppress bone turnover even when iPTH concentration is elevated in long-term KTx recipients. However, hyperparathyroidism with CKD seems to be associated with new clinical fractures during ALN treatment.

CKD-mineral and bone disorder management in kidney transplant recipients

Kidney transplantation, the most effective treatment for the metabolic abnormalities of chronic kidney disease (CKD), only partially corrects CKD-mineral and bone disorders. Posttransplantation bone disease, one of the major complications of kidney transplantation, is characterized by accelerated loss of bone mineral density and increased risk of fractures and osteonecrosis. The pathogenesis of posttransplantation bone disease is multifactorial and includes the persistent manifestations of pretransplantation CKD-mineral and bone disorder, peritransplantation changes in the fibroblast growth factor 23-parathyroid hormone-vitamin D axis, metabolic perturbations such as persistent hypophosphatemia and hypercalcemia, and the effects of immunosuppressive therapies. Posttransplantation fractures occur more commonly at peripheral than central sites. Although there is significant loss of bone density after transplantation, the evidence linking posttransplantation bone loss and subsequent fracture risk is circumstantial. Presently, there are no prospective clinical trials that define the optimal therapy for posttransplantation bone disease. Combined pharmacologic therapy that targets multiple components of the disordered pathways has been used. Although bisphosphonate or calcitriol therapy can preserve bone mineral density after transplantation, there is no evidence that these agents decrease fracture risk. Moreover, bisphosphonates pose potential risks for adynamic bone disease.

Therapeutic management of post-kidney transplant hyperparathyroidism

Left uncontrolled, persistent post-kidney transplant hyperparathyroidism (HPT) may lead to or exacerbate pre-existing bone and cardiovascular disease. Parathyroidectomy has long been the primary treatment option for long-term uncontrolled HPT in post-kidney transplant patients. However, patients with contraindications for surgery and parathyroidectomy-associated complications, including graft loss, highlight the need for other approaches. Conventional medical therapies have limited impact on serum calcium (Ca) and parathyroid hormone (PTH) levels. Bisphosphonates and calcitonin, used to spare bone loss, and phosphorus supplementation, to correct hypophosphatemia, do not directly regulate PTH or Ca. Although vitamin D supplementation can reduce PTH, it is often contraindicated because of hypercalcemia. Studies of the calcimimetic cinacalcet in patients with post-kidney transplant HPT suggest that it can rapidly reduce serum PTH and Ca concentrations while increasing serum phosphorus concentrations toward the normal range. Although the clearest application for cinacalcet is the non-surgical treatment of hypercalcemic patients with persistent HPT, current indications for other transplant patients are as yet uncertain. Further studies are needed to determine the utility of cinacalcet in patients with spontaneous resolution of HPT or low bone turnover. This review discusses the pathophysiology of post-kidney transplant HPT, associated complications, and current options for clinical management.

Osteoporosis following organ transplantation: pathogenesis, diagnosis and management

Organ transplantation has become popular for the management of various chronic illnesses. With the advent of modern immunosuppressive treatments, the longevity of transplant recipients has increased. Consequently, morbid complications such as osteoporosis and bone fractures are seen at an increasing frequency in this population. In most transplant recipients, bone mineral density (BMD) falls shortly after transplantation. However, bone fracture rate plateaus in all except for post-renal transplant patients. Although the underlying pathophysiologic mechanism for this difference is not fully understood, potential mechanisms for sustained bone loss in renal transplant recipients may be persistent phosphorus wasting and defective bone mineralization. Current treatment regimens are based on studies in a small numbers of subjects with BMD as the primary outcome. Although BMD is recognized as a gold standard in the assessment of bone fracture risk, to date, its association with bone fracture risk in the general post-transplant population is not robust. Therefore, randomized controlled trials with bone fracture as the primary end point are crucial. The development of noninvasive bone markers in distinguishing bone turnover and bone mineralization status is also pivotal since skeletal lesions are heterogeneous in various organ transplantations. The elucidation of these underlying skeletal lesions is necessary for the consideration of selective treatment in this population.

Treatment of renal transplant recipients with low bone mineral density: a randomized prospective trial of alendronate, alfacalcidol, and alendronate combined with alfacalcidol

We sought to compare the treatment modalities of alendronate, alfacalcidol, and alendronate combined with alfacalcidol in renal transplant recipients with low bone mineral density. Sixty-four kidney graft recipients (22 women, 42 men) were recruited to this study. Of these 64 patients, 9 served as the control group with T scores more than -1. The remaining 55 patients randomly assigned to treatment had T scores less than -1 and were assigned to 3 groups: group 1 received alfacalcidol (0.5 microg/d); group 2, alendronate (10 mg/d); and group 3, alendronate (10 mg/d) + alfacalcidol (0.5 microg/d per os). Twenty-five patients were allocated to alfacalcidol, 13 patients to alendronate, and 17 patients to alendronate + alfacalcidol treatment. Bone mineral densities of the lumbar spine and femoral neck were measured before and 12 months after treatment. The groups were compared for risk factors of osteoporosis, biochemistry, and bone mineral density. Kruskal-Wallis, one-way ANOVA, and Student t tests were used. With the alendronate + alfacalcidol group, bone mineral density at the lumbar spine significantly increased by 7.9% (P = .006) with a significant improvement in T score (P = .003). Bone mineral density at the femoral neck significantly increased by 8% in the alendronate + alfacalcidol group (P = .01) with a significant improvement in T score (P = .02). The use of a combination of alendronate and alfacalcidol seemed to be safe and more effective than the separate use of the 2 agents to improve bone mass in renal transplant recipients.

Alendronate for the treatment of osteoporosis in men

BACKGROUND

Men have higher rates of osteoporosis and suffer fragility fractures more often than previously believed. Fracture-related morbidity and mortality in men is substantially higher than in women.

OBJECTIVE

To investigate alendronate for treating osteoporosis in men.

METHODS

Search limited to 'men' and 'English'; keywords were 'osteoporosis' or 'bone density' or 'fracture' and 'alendronate'.

RESULTS/CONCLUSIONS

Alendronate is an amino-bisphosphonate with proved efficacy for increasing bone mineral density in men with idiopathic or secondary osteoporosis and has demonstrated an ability to prevent vertebral fractures in men with low bone mass. There are trends for alendronate to decrease the risk of non-vertebral fracture, but larger trials are needed to conclusively establish this benefit. Alendronate is a well-tolerated and comparatively safe drug with an attractive once-a-week dosing regimen.

Post-transplantation osteoporosis

Osteoporosis is prevalent in transplant recipients and is related to pre- and post-transplantation factors. Low bone density and fractures may antedate transplantation, related to traditional risk factors for osteoporosis, effects of chronic illness, and end-stage organ failure and its therapy, on the skeleton. Bone loss after transplantation is related to adverse effects of immunosuppressive drugs (glucocorticoids and calcineurin inhibitors) on bone remodeling. Newer immunosuppressive medications may permit lower doses of glucocorticoids and may be associated with decreased bone loss and fractures. Bisphosphonates are currently the most effective agents for the prevention and treatment of post-transplantation osteoporosis.

Transplantation osteoporosis

In the past two decades, there has been a rapid increase in the number of organ transplanted worldwide, including Brazil, along with an improvement in survival and quality of life of the transplant recipients. Osteoporosis and a high incidence of fragility fractures have emerged as a complication of organ transplantation. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. In addition, most patients have some form of bone disease prior to transplantation, which is usually related to adverse effects of end-stage organ failure on the skeleton. This chapter reviews the mechanisms of bone loss that occur both in the early and late post-transplant periods, as well as the features specific to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and treatment for osteoporosis should be instituted prior and in the early and late phase after transplantation, and will also be addressed in this article.

Effect of bisphosphonates on bone mineral density after renal transplantation as assessed by bone mineral densitometry

INTRODUCTION

Steroid-induced osteoporosis is a major problem after organ transplantation. There is considerable evidence that bisphosphonates are effective in decreasing osteoporosis.

AIM

This prospective study was carried out to see the effects of bisphosphonates on bone mineral density (BMD) after successful renal transplantation.

MATERIAL AND METHODS

Fifty consecutive patients of successful renal transplantation were randomized into two groups. Group A (n = 27) received 35 mg/wk of Alendronate for 6 months after transplantation. Group B (n = 23) did not receive Alendronate and served as a control. Both groups underwent a pretransplant baseline dual-energy X-ray absorptiometry (DEXA) scan of their hips and lumber spines. Both groups received oral calcium and vitamin D supplement. Both groups were matched for the regimen and dose of immunosuppressive drugs. BMD was measured at 3 months and 6 months after transplantation.

RESULTS

Both groups showed a decline in BMD in early months posttransplantation. However, the 6-month DEXA scans showed a significant rise in BMD in group A as compared to group B.

CONCLUSION

Bisphosphonates appear to have a beneficial effect on steroid-induced bone loss.

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.

Bone disease after renal transplantation

It has been well established that a rapid decrease in bone mineral density (BMD) occurs in the first 6 to 12 mo after a successful renal transplantation and persists, albeit at a lower rate, for many years. This rapid BMD loss significantly increases the fracture risk of these patients to levels that are even higher than those of patients who have chronic kidney disease stage 5 and are on dialysis. The presence of low BMD in renal transplant patients as a predictor of risk fracture is controversial. Indeed, as has been suggested also for patients with postmenopausal osteoporosis, there is not a compelling correlation between the decline in BMD and skeletal fractures. However, bone disease after renal transplantation probably represents a unique bone disorder that must encompass underlying renal osteodystrophy. In fact, this syndrome results from multiple factors that include pretransplantation bone status, use of glucocorticoids and other immunosuppressive drugs, hypophosphatemia, and alterations of the calcium-vitamin D axis. Recent studies have demonstrated decreased osteoblast number, reduced bone formation rate, delayed mineralization, and increased osteoblast and osteocyte apoptosis. Bisphosphonates and vitamin D metabolites may be valuable in preventing or diminishing early bone loss. However, clinicians should be careful with the use of bisphosphonates and oversuppression of bone, especially in patients with low bone turnover. New prospective, controlled trials are required to confirm the real efficacy of these drugs, particularly in long-term renal transplant patients.

Effect of kidney transplantation on bone

A broad range of different factors aggravates renal osteodystrophy, which is present in virtually all patients with chronic kidney disease and after successful kidney transplantation. Altered hormonal status, including sex hormones and parathyroid hormone (PTH), a deficit of 1,25(OH)(2) vitamin D(3) (calcitriol), immunosuppressive therapy and post-operative immobilization contribute to a progressive loss of bone density and structure. The decrease of bone mass is particularly prominent during the first 6 months after kidney transplantation and is associated with an increased number of fractures, both compared with the normal population as well as with dialysis patients. At particular risk are patients with a history of diabetes, long duration of haemodialysis and post-menopausal women. To prevent post-transplant bone loss prescription of steroids should be minimized and withdrawn as early as possible. Additional intake of alpha-calcidol [25(OH) vitamin D(3)] or calcitriol, despite normal serum levels, reduces persistent hyperparathyroidism after kidney transplantation, improves intestinal calcium absorption and activates osteoblasts. Inhibition of osteoclasts by biphosphonate therapy seems to effectively reverse bone loss during the early and late course of kidney transplantation. However, as the majority of transplant recipients have a low-turnover bone disease, inhibition of osteoclasts, through which bone turnover is impaired, might further reduce osteoblast activity and promote osteoid synthesis. Most investigations were small-scale studies with 10-100 participants and a follow up of only 12 months. This makes conclusions on the effect of any intervention on the fracture rate impossible. Larger, randomized multicentre studies investigating bone-sparing therapy on hard end points are therefore advocated.

Standards for performing DXA in individuals with secondary causes of osteoporosis

This document addresses skeletal health assessment in individuals with secondary causes of osteoporosis. Recommendations are based on consensus of the Canadian Panel of the International Society for Clinical Densitometry and invited international experts. Bone mineral density (BMD) testing in these populations is performed in conjunction with careful evaluation of the disease state contributing to bone loss and increased fragility fracture risk, as well as assessment of other contributing risk factors for fracture. The presence of secondary causes of bone loss may further increase the risk of fracture independently of BMD and may necessitate earlier pharmacologic intervention. Dual-energy X-ray absorptiometry is indicated in the initial workup of secondary causes of osteoporosis. The BMD fracture risk relationship is not known for individuals with chronic renal failure (CRF). The BMD testing in this population may be normal in the presence of skeletal fragility, and quantitative bone histomorphometry is better at evaluating skeletal status than BMD in CRF. Dual-energy X-ray absorptiometry is a valuable tool in assessing skeletal health in individuals with secondary causes of osteoporosis.

Interventions for preventing bone disease in kidney transplant recipients

BACKGROUND

Patients with chronic kidney disease have significant abnormalities of bone remodelling and calcium 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 that for a patient on dialysis. Trials reporting the use of bisphosphonates, vitamin D analogues, calcitonin, and hormone replacement therapy to treat bone disease following engraftment exist.

OBJECTIVES

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

SEARCH STRATEGY

The Cochrane CENTRAL Register of Controlled Trials (The Cochrane Library - Issue 3 2004), MEDLINE (1966 to August 2004), EMBASE (1980- August 2004) and reference lists were searched without language restriction.

SELECTION CRITERIA

Randomised trials of treatment of bone disease following kidney transplantation were included. Trials of recipients of any transplant other than a kidney transplant including trials of kidney-pancreas transplants were excluded.

DATA COLLECTION AND ANALYSIS

Two authors assessed independently 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. For continuous variables the weighted mean difference (WMD) and its 95% CI was used.

MAIN RESULTS

Twenty-three eligible trials (1,209 patients) were identified. Seven trials compared more than two interventions. Nineteen trials compared active treatment with placebo, five vitamin D analogue and calcium, six vitamin D analogue alone, twelve bisphosphonates, and four nasal calcitonin. Eight trials compared two active treatments, one 17-beta oestradiol and medroxyprogesterone versus vitamin D analogue, five bisphosphonate versus vitamin D analogue, two vitamin D analogue and calcium versus calcium and one bisphosphonate versus calcitonin. Methodological quality was suboptimal. There were no significant differences between any treatment group for risk of fracture. Bisphosphonate, administered by any route, vitamin D analogue and calcitonin all had a beneficial effect on the bone mineral density at the lumbar spine. Bisphosphonates and vitamin D analogue had a beneficial effect on the bone mineral density at the femoral neck. Few or no data were available for combined hormone replacement, testosterone, selective oestrogen receptor modulators, fluoride or anabolic steroids. All-cause mortality and drug-related toxicity were reported infrequently and there was no statistical difference between treatment groups.

AUTHORS' CONCLUSIONS

No benefit from any intervention known to reduce risk of fracture from bone disease could be demonstrated to reduce fracture incidence in kidney transplant recipients.

Interventions for preventing bone disease in kidney transplant recipients: A systematic review of randomized controlled trials

BACKGROUND

Before renal transplantation complex abnormalities of bone metabolism exist and lead to increased risk for fracture after transplantation. This study was conducted to assess the evidence available to guide targeted treatment to reduce bone disease in transplant recipients.

METHODS

The Cochrane CENTRAL Registry, MEDLINE, and EMBASE were searched for randomized trials of interventions for bone disease after renal transplantation. Data were extracted on fracture, bone mineral density (BMD) by means of dual-energy X-ray absorptiometry, acute graft rejection, and adverse events. Analysis was performed with a random-effects model, and all results are expressed as relative risk with 95% confidence intervals (CIs).

RESULTS

Twenty-three eligible trials (1,209 patients) were identified. No trial found a reduction in risk for fracture. Bisphosphonates (7 trials; 268 patients; weighted mean difference [WMD], 7.66; 95% CI, 4.82 to 10.50), vitamin D analogues (2 trials; 51 patients; WMD, 6.13; 95% CI, 4.97 to 7.29), and calcitonin (1 trial; 31 patients; WMD, 5.00; 95% CI, 0.88 to 9.12) favorably affected the percentage of change in BMD at the lumbar spine compared with no treatment. Bisphosphonates (4 trials; 149 patients; WMD, 7.18; 95% CI, 6.22 to 8.13) and vitamin D analogues (2 trials; 51 patients; WMD, 3.73; 95% CI, 2.71 to 4.75), but not calcitonin (1 trial; 31 patients; WMD, -0.30; 95% CI, -5.00 to 4.40), had a favorable effect on BMD measured at the femoral neck compared with no treatment. The incidence of reported toxicity was low.

CONCLUSION

The trials were inadequately powered to show a reduction in risk for fracture. Bisphosphonates and vitamin D have a beneficial effect on BMD at the lumbar spine and femoral neck. With increasing survival after renal transplantation, this study stresses the importance of randomized controlled trial evidence of interventions of bone disease after renal transplantation.

Management of bone loss after organ transplantation

Organ transplant recipients experience rapid bone loss and high fracture rates, particularly during the early post-transplant period. Early rapid bone loss occurs in the setting of uncoupled bone turnover with increased bone resorption and decreased bone formation. Because there are no clinical factors that reliably predict post-transplant bone loss and fractures in the individual patient, all transplant recipients should be considered candidates for early preventive therapy for osteoporosis. Long-term transplant recipients with densitometric osteoporosis and/or fractures should also receive treatment. Although active metabolites of vitamin D and bisphosphonates have both shown efficacy, data from clinical trials suggest that bisphosphonates are the safest and most consistently effective agents for the prevention and treatment of post-transplantation osteoporosis in adults. Kidney transplant recipients represent a special population, and more research is needed to delineate the risks and benefits of treating bone disease in these patients.

Osseous complications of pediatric transplantation

Adult stature and peak bone mass are achieved through childhood growth and development. Multiple factors impair this process in children undergoing solid organ transplantation, including chronic illness, pretransplant osteodystrophy, use of medications with negative impact on bone, and post-transplant renal dysfunction. While growth delay and short stature remain common, the most severe forms of transplant-related bone disease, fracture and avascular necrosis, appear to have become less common in the pediatric age group. Osteopenia is very prevalent in adult transplant recipients and probably also in pediatrics, but its occurrence and sequelae are difficult to study in these groups due to methodological shortfalls of planar densitometry related to short stature and altered patterns of growth and development. Although the effect on lifetime peak bone mass is not clear, data from adult populations suggest an elevated long-term risk of bone disease in children receiving transplants. Optimal management of pretransplantation osteodystrophy, attention to post-transplant renal insufficiency among both renal and non-renal transplant patients, reduction of steroid dose in select patients, and supplementation with calcium plus vitamin D during expected periods of maximal bone loss may improve bone health. Careful research is required to determine the role of bisphosphonate therapy in pediatric transplantation.