The effect of oral bisphosphonate therapy on vertebral morphometry and fractures in patients with Duchenne muscular dystrophy and glucocorticoid-induced osteoporosis

Growth hormone and testosterone delay vertebral fractures in boys with muscular dystrophy on chronic glucocorticoids

Glucocorticoid use in Duchenne and Becker muscular dystrophy prolongs ambulation but cause significant skeletal toxicity. Our analysis has immediate clinical implications, suggesting that growth hormone and testosterone have a stronger effect prior to first and subsequent vertebral fracture, respectively, relative to bisphosphonates alone in children with dystrophinopathies on chronic glucocorticoids.

PURPOSE

Glucocorticoids prolong ambulation in boys with Duchenne muscular dystrophy; however, they have significant endocrine side effects. We assessed the impact of growth hormone (GH), testosterone, and/or zoledronic acid (ZA) on vertebral fracture (VF) incidence in patients with dystrophinopathies on chronic glucocorticoids.

METHODS

We conducted a longitudinal retrospective review of 27 males with muscular dystrophy. Accelerated failure time (AFT) models were used to estimate the relative time to VF while on GH, testosterone, and/or ZA compared to ZA alone. Results are reported as failure time ratio, where >1 indicates prolonged time versus <1 indicates shorter time to next VF.

RESULTS

The prevalence of growth impairment was 96% (52% utilized GH), pubertal delay was 86% (72% utilized testosterone), and low trauma fractures were 87% (72% utilized ZA). Multivariable analysis of the AFT models showed that participants on either GH or testosterone treatment relative to ZA alone experienced prolonged time to next VF (1.253, P<0.001), with GH being the significant contributor when analyzed independently from testosterone (1.229, P<0.001). Use of ZA with GH or testosterone relative to ZA alone resulted in prolonged time to next VF (1.171, P<0.001), with testosterone being a significant contributor (1.130, P=0.033).

CONCLUSION

GH and testosterone each decreased VF risk in patients independent of or in combination with ZA, respectively.

Bisphosphonates in Glucocorticoid-Treated Patients With Duchenne Muscular Dystrophy: A Systematic Review and Grading of the Evidence

BACKGROUND AND OBJECTIVES

Bisphosphonates are routinely used to treat osteoporosis in patients with Duchenne muscular dystrophy (DMD), a rare, severely debilitating neuromuscular disease. We sought to synthesize and grade benefits and harms evidence of bisphosphonates in glucocorticoid-treated patients with DMD.

METHODS

In this systematic review (PROSPERO identifier: CRD42020157606), we searched MEDLINE, CINAHL, Embase, PsycINFO, Web of Science, and CENTRAL for articles published from inception up to and including March 31, 2023, reporting results in any language from any study type. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations framework.

RESULTS

We identified 19 publications involving 1,010 children and adults from 12 countries across all inhabited continents except South America. We found high-quality evidence that bisphosphonates significantly increase the areal lumbar spine bone mineral density (BMD) Z score in glucocorticoid-treated patients with DMD. The greatest improvements were recorded in controlled settings among patients treated with intravenous zoledronate. Evidence of benefits to fracture risks was inconclusive and/or of low quality, primarily due to lack of controlled data and small samples. Bisphosphonates were generally well-tolerated, although adverse events related to the first infusion (i.e., "acute phase reaction") were frequently reported.

DISCUSSION

There is high-quality evidence supporting the use of bisphosphonates to increase the areal lumbar spine BMD Z score in patients with DMD and glucocorticoid-induced osteoporosis. Our synthesis and grading affirm current recommendations put forward in the 2018 DMD Clinical Care Considerations and should be helpful in raising awareness about anticipated benefits of bisphosphonates, prevailing unmet needs, and potential safety issues in their use.

Denosumab, teriparatide and bisphosphonates for glucocorticoid-induced osteoporosis: a Bayesian network meta-analysis

Background: Several medications have been used for glucocorticoids-induced osteoporosis (GIO). However, the best therapeutic option for GIO is still controversial. A Bayesian network meta-analysis was conducted to compare the efficacy and safety of denosumab, teriparatide and bisphosphonates for patients with GIO. Methods: Relevant randomized controlled trials published in PubMed, Embase, Cochrane Library and ClinicalTrials.gov up to August 2023 were searched. The following efficiency and safety outcomes were extracted for comparison: bone mineral density (BMD) percentage changes in lumbar spine, femur neck and total hip, and incidences of adverse events (AEs), serious adverse events (SAEs), vertebrae and non-vertebrae fracture. Bayesian random effects models were used for multiple treatment comparisons. Results: 11 eligible RCTs involving 2,877 patients were identified. All the six medications including alendronate, risedronate, etidronate, zoledronate, teriparatide, and denosumab and were effective in increasing BMD. Teriparatide and denosumab were more effective in improving lumbar spine and femur neck BMD, and reducing vertebrae fracture. Alendronate and denosumab were more effective in improving total hip BMD. Alendronate and teriparatide had the lowest incidences of AEs and SAEs. Conclusion: Teriparatide denosumab and the bisphosphonates are all effective in improving BMD for GIO patients. Based on this network meta-analysis, teriparatide and denosumab have higher efficiency in improving lumbar spine and femur neck BMD, and reducing vertebrae fracture. Systematic Review Registration: 10.17605/OSF.IO/2G8YA, identifier CRD42023456305.

Risk Factors Associated with Incident Vertebral Fractures in Steroid-treated Males with Duchenne Muscular Dystrophy

PURPOSE

Prevention of fractures is an unmet need in glucocorticoid (GC)-treated Duchenne muscular dystrophy. This study explored factors associated with incident vertebral fractures (VFs) to inform future fracture prevention efforts.

METHODS

VFs were evaluated prospectively at study baseline and 12 months on lateral spine radiographs in participants aged 4 to 25 years with Duchenne muscular dystrophy. Clinical factors were analyzed for their association with the change in Spinal Deformity Index (sum of the Genant-defined VF grades from T4 to L4) between baseline and 12 months.

RESULTS

Thirty-eight males were evaluated (mean ± SD age at baseline 11.0 ± 3.6 years; mean ± SD GC duration at baseline 4.1 ± 3.1 years; 74% ambulatory). Nine of 38 participants (24%) had 17 incident VFs, of which 3/17 VFs (18%) were moderate/severe. Participants with 12-month incident VF had lower mean ± SD baseline lumbar spine areal bone mineral density Z-scores (-2.9 ± 1.0 vs -1.9 ± 1.1; P = .049) and lower total body less head areal bone mineral density Z-scores (-3.1 ± 1.2 vs -1.6 ± 1.7; P = .036). Multivariable linear regression showed that at least 1 VF at baseline (P < .001), a higher number of antecedent non-VF (P < .001), and greater bone age delay at baseline (P = .027) were significant predictors of an increase in the Spinal Deformity Index from baseline to 12 months.

CONCLUSION

The observation that ≥ 1 prevalent VF and/or non-VF were the strongest predictors of incident VFs at 12 months supports the need for prevention of first fractures in this high-risk setting. Bone age delay, a marker of GC exposure, may assist in the prioritization of patients in efforts to prevent first fractures.

Child Abuse, Misdiagnosed by an Expertise Center-Part II-Misuse of Bayes' Theorem

A newborn girl had, from two weeks on, small bruises on varying body locations, but not on her chest. Her Armenian grandmother easily bruised, too. Her mother was diagnosed with hypermobility-type Ehlers-Danlos-Syndrome (hEDS), an autosomal dominant connective tissue disorder, with a 50% inheritance probability. Referral to a University Medical Center located "Dutch Expertise Center for Child Abuse" resulted (prior to consultation) in physical abuse suspicion. Protocol-based skeletal X-rays showed three healed, asymptomatic rib fractures. A protocol-based Bayesian likelihood ratio guesstimation gave 10-100, erroneously used to suggest a 10-100 times likelier non-accidental-than-accidental cause. Foster care placement followed, even in a secret home, where she also bruised, suggesting hEDS inheritance. Correct non-accidental/accidental Bayes' probability of symptoms is (likelihood ratio) × (physical abuse incidence). From the literature, we derived an infant abuse incidence between about ≈0.0009 and ≈0.0026 and a likelihood ratio of <5 for bruises. For rib fractures, we used a zero likelihood ratio, arguing their cause was birth trauma from the extra delivery pressure on the chest, combined with fragile bones as the daughter of an hEDS-mother. We thus derived a negligible abuse/accidental probability between <5 × 0.0009 <0.005 and <5 × 0.0026 <0.013. The small abuse incidence implies that correctly using Bayes' theorem will also miss true infant physical abuse cases. Curiously, because likelihood ratios assess how more often symptoms develop if abuse did occur versus non-abuse, Bayes' theorem then implies a 100% infant abuse incidence (unwittingly) used by LECK. In conclusion, probabilities should never replace differential diagnostic procedures, the accepted medical method of care. Well-known from literature, supported by the present case, is that (child abuse pediatrics) physicians, child protection workers, and judges were unlikely to understand Bayesian statistics. Its use without statistics consultation should therefore not have occurred. Thus, Bayesian statistics, and certainly (misused) likelihood ratios, should never be applied in cases of physical child abuse suspicion. Finally, parental innocence follows from clarifying what could have caused the girl's bruises (inherited hEDS), and rib fractures (birth trauma from fragile bones).

Comparison of denosumab and oral bisphosphonates for the treatment of glucocorticoid-induced osteoporosis: a systematic review and meta-analysis

BACKGROUND

Both denosumab and bisphosphonates have been demonstrated effective for glucocorticoid-induced osteoporosis. However, evidence-based medicine is still lacking to prove the clinical results between denosumab and bisphosphonates. This meta-analysis aims to compare the efficacy and safety between denosumab and oral bisphosphonates for the treatment of glucocorticoid-induced osteoporosis through evidence-based medicine.

METHODS

MEDLINE, EMBASE, and the Cochrane library databases were searched up to June 2022 for randomized controlled trials that compared denosumab and oral bisphosphonates in the treatment of glucocorticoid-induced osteoporosis. The following outcomes were extracted for comparison: percentage change in bone mineral density from baseline at the lumbar spine, total hip, femoral neck, and ultra-distal radius; percentage change from baseline in serum concentration of bone turnover markers; and incidence of treatment-emergent adverse events.

RESULTS

Four randomized controlled trials involving 714 patients were included. The pooled results showed that denosumab was superior to bisphosphonates in improving bone mineral density in lumbar spine (mean difference (MD) 1.70; 95% confidence interval (CI) 1.11-2.30; P < 0.001) and ultra-distal radius (MD 0.87; 95% CI 0.29-1.45; P = 0.003), and in suppressing C-terminal telopeptide of type 1 collagen (MD -34.83; 95% CI -67.37--2.28; P = 0.04) and procollagen type 1 N-terminal propeptide (MD -14.29; 95% CI -23.65- -4.94; P = 0.003) at 12 months. No significant differences were found in percentage change in total hip or femoral neck bone mineral density at 12 months, or in the incidence of treatment-emergent adverse events or osteoporosis-related fracture.

CONCLUSIONS

Compared with bisphosphonates, denosumab is superior in improving bone mineral density in lumbar spine and ultra-distal radius for glucocorticoid-induced osteoporosis. Further studies are needed to prove the efficacy of denosumab.

Effectiveness of Neridronate in the Management of Bone Loss in Patients with Duchenne Muscular Dystrophy: Results from a Pilot Study

INTRODUCTION

Bone loss is a major issue in patients affected by Duchenne muscular dystrophy (DMD), a rare musculoskeletal disorder, particularly in those treated with glucocorticoids (GCs). We aimed to assess the effectiveness of neridronate in terms of bone mineral density (BMD) changes in this population.

METHODS

We retrospectively reviewed the records of patients affected by DMD receiving GCs referred to our outpatient from 2015 to 2020. All patients were treated with an intramuscular (IM) injection of neridronate (25 mg every month). Bone density was measured at the lumbar spine (LS; L1-L4 tract) using dual-energy x-ray absorptiometry (DXA) (GE Lunar), no more than 4 weeks before (T0) and after 1 year from neridronate treatment (T1).

RESULTS

Eight boys with DMD were included with a mean age at diagnosis of 4.75 ± 2.81 years. Six of them were non-ambulant and two of them had previous low-trauma fractures (a distal femur fracture and a vertebral compression fracture, respectively). All patients were receiving deflazacort [median duration of therapy 11.5 years (interquartile range 2-25)]. At the DXA evaluation (T0), the mean L1-L4 BMD value was 0.716 ± 0.164 g/cm². Six patients (75%) showed an L1-L4 Z-score height-adjusted of less than - 2. The mean age of neridronate initiation was 18.87 ± 6.81 years. All patients were supplemented with calcium carbonate and vitamin D at baseline. After 12 months of treatment (T1), the mean L1-L4 BMD value was 0.685 ± 0.190 g/cm². Seven patients (87.5%) showed an L1-L4 Z-score of less than - 2. Changes in LS BMD and Z-score were not significant between T0 and T1 in our cohort (p = 0.674 and p = 0.208, respectively) as well as among non-ambulant patients with DMD without previous fragility fractures.

CONCLUSIONS

In this study, we reported for the first time that neridronate may slow bone loss in GC-treated patients with DMD at 1-year follow-up.