Glucocorticoid-induced osteoporosis: from clinical trials to clinical practice

Romosozumab versus denosumab in long-term users of glucocorticoids: A pilot randomized controlled trial

OBJECTIVE

To compare the efficacy of romosozumab (ROMO) and denosumab (DEN) in prevalent long-term glucocorticoid (GC) users.

METHODS

Adult patients receiving oral prednisolone (≥5 mg/day) with high risk of fracture were randomized to receive subcutaneous ROMO (210 mg monthly) or DEN (60 mg 6-monthly) for 12 months, followed by DEN for two more doses. The primary end point was the change in spine bone mineral density (BMD) from Months 0 to 12. Secondary end points included changes in BMD of the spine/hip/femoral neck and bone turnover markers at various time points and adverse events.

RESULTS

Seventy patients (age 62.6 ± 9.1 years; 96% women; median prednisolone dose 5.0 mg/day; duration of therapy 10.7 ± 7.4 years) were enrolled, and 63 completed the study. At Month 12, the spine BMD increased significantly in both ROMO (+7.3% ± 4.5%; p < 0.001) and DEN (+2.3% ± 3.1%; p < 0.001) groups. The absolute spine BMD gain from Months 0 to 12 was significantly greater in ROMO-treated patients (p < 0.001). Although the total hip BMD at Month 12 also increased significantly in the ROMO (+1.6% ± 3.3%; p = 0.01) and DEN groups (+1.6% ± 2.6%; p = 0.003), the absolute BMD gain was not significantly different between the groups. At Month 24, the spine BMD continued to increase in both the ROMO (+9.7% ± 4.8%; p < 0.001) and DEN group (+3.0% ± 3.0%; p < 0.001) compared to baseline, and the absolute BMD gain remained significantly greater in ROMO-treated patients. The total hip BMD continued to increase in both groups (ROMO +2.9% ± 3.7%; p < 0.001; DEN +2.2% ± 3.4%; p = 0.001), but the changes from baseline were similar. Injection site reaction was more frequently reported in ROMO-treated patients.

CONCLUSION

ROMO was superior to DEN in raising the spine BMD at Month 12 in chronic GC users. After switching to DEN, ROMO-treated patients continued to gain spine BMD to a greater extent than DEN until Month 24.

Risk of fracture in women with glucocorticoid requiring diseases is independent from glucocorticoid use: An analysis on a nation-wide database

OBJECTIVE

Glucocorticoid-induced osteoporosis (GIOP) is a common cause of secondary osteoporosis. However, glucocorticoid requiring diseases pose a risk themselves for fracture. The aim of the present study was to determine the risk of fracture associated with variety of glucocorticoid requiring diseases independently from glucocorticoid use and other risk factors for osteoporosis.

METHODS

We conducted a retrospective cross-sectional analysis of a nation-wide cohort (DeFRACalc79 database). We used multivariable regression analysis adjusting for several risk factors for fracture and glucocorticoid intake to estimate the independent role of glucocorticoid requiring illnesses on fracture risk.

RESULTS

We found that patients with rheumatoid arthritis, connective tissue diseases, chronic obstructive pulmonary disease (COPD) and neurological diseases were at greater risk of vertebral or hip fracture (crude ORs 1.31, 1.20, 1.92 and 2.97 respectively). After adjusting for potential confounders COPD and neurological diseases remained significantly associated with an increased risk of vertebral or hip fractures (aORs 1.33, 95 % CI 1.18-1.49 and 2.43, 95 % CI 2.17-2.74). Rheumatoid arthritis, COPD, IBD and neurological diseases also significantly increased the risk of non-vertebral, non-hip fractures (aORs 1.23, 1.42, 1.52 and 1.94 respectively).

CONCLUSION

Some glucocorticoid requiring diseases were independently associated with an increased risk of fractures. COPD and neurological diseases with both vertebral and non-vertebral fracture risk while RA and IBD were independently associated only with non-vertebral, non-hip fractures.

Pharmaceutical treatment of bone loss: From animal models and drug development to future treatment strategies

Animal models are fundamental to advance our knowledge of the underlying pathophysiology of bone loss and to study pharmaceutical countermeasures against it. The animal model of post-menopausal osteoporosis from ovariectomy is the most widely used preclinical approach to study skeletal deterioration. However, several other animal models exist, each with unique characteristics such as bone loss from disuse, lactation, glucocorticoid excess, or exposure to hypobaric hypoxia. The present review aimed to provide a comprehensive overview of these animal models to emphasize the importance and significance of investigating bone loss and pharmaceutical countermeasures from perspectives other than post-menopausal osteoporosis only. Hence, the pathophysiology and underlying cellular mechanisms involved in the various types of bone loss are different, and this might influence which prevention and treatment strategies are the most effective. In addition, the review sought to map the current landscape of pharmaceutical countermeasures against osteoporosis with an emphasis on how drug development has changed from being driven by clinical observations and enhancement or repurposing of existing drugs to today's use of targeted anti-bodies that are the result of advanced insights into the underlying molecular mechanisms of bone formation and resorption. Moreover, new treatment combinations or repurposing opportunities of already approved drugs with a focus on dabigatran, parathyroid hormone and abaloparatide, growth hormone, inhibitors of the activin signaling pathway, acetazolamide, zoledronate, and romosozumab are discussed. Despite the considerable progress in drug development, there is still a clear need to improve treatment strategies and develop new pharmaceuticals against various types of osteoporosis. The review also highlights that new treatment indications should be explored using multiple animal models of bone loss in order to ensure a broad representation of different types of skeletal deterioration instead of mainly focusing on primary osteoporosis from post-menopausal estrogen deficiency.

Antiresorptive treatments for corticosteroid-induced osteoporosis: a Bayesian network meta-analysis

INTRODUCTION

Corticosteroid-induced osteoporosis (CIO) is the most common type of secondary osteoporosis, leading to fractures, and increased morbidity and mortality.

SOURCE OF DATA

Pubmed, EMBASE, Scopus and Google Scholar databases.

AREAS OF AGREEMENT

Prolonged glucocorticoids administration leads to secondary osteoporosis.

AREAS OF CONTROVERSY

The optimal management for CIO is controversial.

GROWING POINTS

The present study compared bone mineral density, fractures and adverse events in patients undergoing treatment with risedronate, alendronate, zoledronate, denosumab or etidronate for CIO.

AREAS TIMELY FOR DEVELOPING RESEARCH

For selected patients with CIO, alendronate performed better overall. These results must be interpreted within the limitations of the present study.

LEVEL OF EVIDENCE

I, Bayesian network meta-analysis of randomized clinical trials.

Real-life short-term effectiveness of anti-osteoporotic treatments: a longitudinal cohort study

Introduction:

Randomized clinical trials have shown that anti-osteoporotic treatments can increase bone mineral density (BMD) and reduce the incidence of fragility fractures. However, data on the real-life effectiveness of anti-osteoporotic medications are still scarce.

Methods:

We conducted a cohort study on women at high risk of fracture. We retrieved clinical and densitometric data from the DeFRA database, which derives from the DeFRA tool, a web-based fracture risk assessment tool. Multivariable Cox regression survival models were employed to analyze the effectiveness of different anti-osteoporotic drugs on fracture. In sensitivity analyses, we conducted 1:1 propensity score matching analyses.

Results:

Data on 50,862 women were available. Among these, 3574 individuals had at least two consecutive visits. The crude fracture rate was 91.9/1000 person-year for non-treated patients. The crude fracture rate in bisphosphonate users was 72.1/1000 person-year, in denosumab users was 58.2/1000 person-year, and in teriparatide users was 19.3/1000 person-year. Overall, we found that bisphosphonate use was associated with a 30% lower risk of fracture compared to no treatment [adjusted hazard ratio (aHR): 0.70, 95% confidence interval (CI): 0.50–0.98]. Treatment with denosumab and teriparatide were associated with 60% and 90% lower risk of fracture, respectively (aHR: 0.43, 95% CI: 0.24–0.75 and aHR: 0.09, 95% CI: 0.01–0.70). Bisphosphonate use was associated with a lower risk of fracture only after 1 year of treatment.

Conclusion:

In conclusion, we found that all anti-osteoporotic medications considered in the study effectively reduced the risk of fracture in the real-life. The effect of bisphosphonate on fracture risk was apparent only after the first year of treatment. Our findings do not support the use of bisphosphonates in patients at imminent risk of fracture.

The RNA-binding protein Musashi2 governs osteoblast-adipocyte lineage commitment by suppressing PPARγ signaling

Osteoporosis caused by aging is characterized by reduced bone mass and accumulated adipocytes in the bone marrow cavity. How the balance between osteoblastogenesis and adipogenesis from bone marrow mesenchymal stem cells (BMSCs) is lost upon aging is still unclear. Here, we found that the RNA-binding protein Musashi2 (Msi2) regulates BMSC lineage commitment. Msi2 is commonly enriched in stem cells and tumor cells. We found that its expression was downregulated during adipogenic differentiation and upregulated during osteogenic differentiation of BMSCs. Msi2 knockout mice exhibited decreased bone mass with substantial accumulation of marrow adipocytes, similar to aging-induced osteoporosis. Depletion of Msi2 in BMSCs led to increased adipocyte commitment. Transcriptional profiling analysis revealed that Msi2 deficiency led to increased PPARγ signaling. RNA-interacting protein immunoprecipitation assays demonstrated that Msi2 could inhibit the translation of the key adipogenic factor Cebpα, thereby inhibiting PPAR signaling. Furthermore, the expression of Msi2 decreased significantly during the aging process of mice, indicating that decreased Msi2 function during aging contributes to abnormal accumulation of adipocytes in bone marrow and osteoporosis. Thus, our results provide a putative biochemical mechanism for aging-related osteoporosis, suggesting that modulating Msi2 function may benefit the treatment of bone aging.

Comprehensive circRNA Analyses in Human Vertebrae of GIOP and Its Molecular Mechanism

Circular RNAs (circRNAs) are a novel class of noncoding RNAs that play important roles in human diseases. However, the regulation of circRNAs in glucocorticoid-induced osteoporosis (GIOP) has not been reported. In this study, we performed high-throughput sequencing to identify altered circRNAs in the vertebrae from GIOP patients. A total of 65 clinical samples were collected in this study. Bioinformatics algorithms were employed to predict the target relationship between circRNAs and miRNAs and the circRNAs-miRNAs regulatory network. We focused on the top 10 significantly up-/downregulated circRNAs (hsa_circ_0004906, hsa_circ_0001172, hsa_circ_0005778, hsa_circ_0004276, hsa_circ_0005729, hsa_circ_0006173, hsa_circ_0007662, hsa_circ_0001451, hsa_circ_0001564, and hsa_circ_0108735) and measured their expression by qRT-PCR in clinical samples. Bioinformatics analyses demonstrated that 87 miRNAs were predicted in upregulated circRNAs and 104 miRNAs were predicted in downregulated circRNAs. The functional enrichment analysis showed these targeted miRNAs were significantly enriched in bone metabolism-related biological processes and pathways, including the MAPK signaling pathway, positive regulation of the metabolic process and metabolic pathways, etc. Collectively, our study revealed circRNA regulation and circRNAs-miRNAs regulatory network in GIOP for the first time, which provides a new perspective on the molecular mechanism of GIOP and lays a foundation for GIOP treatment.

Animal Model for Glucocorticoid Induced Osteoporosis: A Systematic Review from 2011 to 2021

Clinical and experimental data have shown that prolonged exposure to GCs leads to bone loss and increases fracture risk. Special attention has been given to existing emerging drugs that can prevent and treat glucocorticoid-induced osteoporosis GIOP. However, there is no consensus about the most relevant animal model treatments on GIOP. In this systematic review, we aimed to examine animal models of GIOP centering on study design, drug dose, timing and size of the experimental groups, allocation concealment, and outcome measures. The present review was written according to the PRISMA 2020 statement. Literature searches were performed in the PubMed electronic database via Mesh with the publication date set between April, 2011, and February 2021. A total of 284 full-text articles were screened and 53 were analyzed. The most common animal species used to model GIOP were rats (66%) and mice (32%). In mice studies, males (58%) were preferred and genetically modified animals accounted for 28%. Our work calls for a standardization of the establishment of the GIOP animal model with better precision for model selection. A described reporting design, conduction, and selection of outcome measures are recommended.

German Society of Rheumatology recommendations for management of glucocorticoid-induced osteoporosis

BACKGROUND

Glucocorticoids are of substantial therapeutic importance in the treatment of inflammatory diseases, but are also associated with bone mineral density loss, osteoporosis, and fractures, especially with long-term use.

OBJECTIVE

To develop recommendations for the management of glucocorticoid-induced osteoporosis (GIOP) in adult patients on long-term glucocorticoid (GC) treatment.

METHODS

A systematic literature search (SLR) was conducted to synthesize the evidence for GIOP prevention and treatment options. Recommendations were developed based on SLR/level of evidence and by previously defined questions and in a structured group consensus process.

RESULTS

Recommendations include supplementation with calcium and vitamin D under long-term GC therapy in adults. If specific osteologic treatment is indicated, we recommend bisphosphonates or denosumab as first-line treatment. If fracture risk is high, we recommend teriparatide as primary specific osteologic treatment. Denosumab should be used in cases of severe renal insufficiency, and specific osteologic treatment should not be given in pregnancy. For patients who have not reached the treatment goal, a switch to another class of specific osteologic drugs should be performed. We recommend re-evaluation after a treatment duration of 3-5 years or after termination of long-term GC treatment.

CONCLUSION

This work aims to provide evidence-based and consensus-based recommendations for the best possible management of GIOP in Germany and to support treatment decisions.

[German Society of Rheumatology Recommendations for the management of glucocorticoid-induced Osteoporosis. German version]

BACKGROUND

Glucocorticoids are of substantial therapeutic importance in the treatment of inflammatory diseases, but are also associated with bone mineral density loss, osteoporosis, and fractures, especially with long-term use.

OBJECTIVE

To develop recommendations for the management of glucocorticoid-induced osteoporosis (GIOP) in adult patients on long-term glucocorticoid (GC) treatment.

METHODS

A systematic literature search (SLR) was conducted to synthesize the evidence for GIOP prevention and treatment options. Recommendations were developed based on SLR/level of evidence and by previously defined questions and in a structured group consensus process.

RESULTS

Recommendations include supplementation with calcium and vitamin D under long-term GC therapy in adults. If specific osteologic treatment is indicated, we recommend bisphosphonates or denosumab as first-line treatment. If fracture risk is high, we recommend teriparatide as primary specific osteologic treatment. Denosumab should be used in cases of severe renal insufficiency, and specific osteologic treatment should not be given in pregnancy. For patients who have not reached the treatment goal, a switch to another class of specific osteologic drugs should be performed. We recommend re-evaluation after a treatment duration of 3-5 years or after termination of long-term GC treatment.

CONCLUSION

This work aims to provide evidence-based and consensus-based recommendations for the best possible management of GIOP in Germany and to support treatment decisions.

Metabolic Disorders and Mineral Density of the Bone Tissue in the Early Pathogenesis of Osteonecrosis: Study on Rabbits with Steroid-Induced Osteonecrosis

The relationship between the appearance of bone metabolism disorders and the onset of steroid-induced osteonecrosis remains unclear. We studied the time course of calcium, phosphorus, osteocalcin, alkaline phosphatase, and mineral density of bone tissue in the subchondral bone of the femoral head of rabbits injected with steroids and attempted to precisely determine the time when disorders in bone metabolism started in animals with steroid-induced osteonecrosis. We detected bone metabolism disorders involved in the early pathogenesis of steroid-induced osteonecrosis, which were the cause, but not the result of this condition.

Glucocorticoids and Trabecular Bone Score

TBS (Trabecular Bone Score) is the latest tool for clinicians to evaluate bone micro-architecture based on a pixel greyscale, which is provided by lumbar dual-energy X-ray absorptiometry (DXA). Its use enhances fracture prediction in addition to DXA-BMD (Bone Mineral Density). This is independent of fracture risk assessment (FRAX) and DXA results. We present a narrative review regarding the connection between TBS and Glucocorticoids (GC), either as a drug used for different conditions or as a tumor-produced endogenous excess.

TBS is a better discriminator for GC-induced vertebral fractures compared to DXA-BMD. This aspect is similarly available for patients with osteoporosis diagnosed by DXA. TBS is inversely correlated with the cumulative dose of GC (systemic or inhaled), with disease duration, and positively correlated with respiratory function in patients with asthma. Low TBS values are found in females with a T-score at the hip within the osteoporosis range, with diabetes mellitus, or who use GC. Lumbar TBS is a screening tool in menopausal women with type 2 diabetes mellitus. TBS is an independent parameter that provides information regarding skeleton deterioration in diabetic patients receiving GC therapy in a manner complementary to DXA-BMD. TBS might become an essential step regarding the adrenalectomy decision in patients with adrenal incidentaloma in whom autonomous cortisol secretion might damage bone micro-architecture. TBS currently represents a standard tool of fracture risk evaluation in patients receiving GC therapy or with endogenous Cushing’s syndrome, a tool easy to be applied by different practitioners since GCs are largely used

Mechanisms of Bone Fragility: From Osteogenesis Imperfecta to Secondary Osteoporosis

Bone material strength is determined by several factors, such as bone mass, matrix composition, mineralization, architecture and shape. From a clinical perspective, bone fragility is classified as primary (i.e., genetic and rare) or secondary (i.e., acquired and common) osteoporosis. Understanding the mechanism of rare genetic bone fragility disorders not only advances medical knowledge on rare diseases, it may open doors for drug development for more common disorders (i.e., postmenopausal osteoporosis). In this review, we highlight the main disease mechanisms underlying the development of human bone fragility associated with low bone mass known to date. The pathways we focus on are type I collagen processing, WNT-signaling, TGF-ß signaling, the RANKL-RANK system and the osteocyte mechanosensing pathway. We demonstrate how the discovery of most of these pathways has led to targeted, pathway-specific treatments.

Evaluation of risk factors of vertebral fracture in Japanese female patients with glucocorticoid-induced osteoporosis

Background

Glucocorticoid-induced osteoporosis and vertebral fracture are common complications in patients on glucocorticoid treatment for rheumatological diseases. The present study aimed to identify the risk factors of vertebral fracture in Japanese female patients with glucocorticoid-induced osteoporosis.

Methods

This study included 225 Japanese women with glucocorticoid-induced osteoporosis and 72 patients with postmenopausal osteoporosis. All participants were treated with bisphosphonate or denosumab for osteoporosis with active form of vitamin D for at least 3 years. The differences of clinical parameters, including age, disease duration, body mass index (BMI), bone mineral density (BMD), and the dose and treatment duration of glucocorticoid were assessed between patients with and without vertebral fracture. Multivariate logistic regression analysis was also performed to evaluate the association of vertebral fracture with clinical parameters.

Results

The significant differences related to age, BMD of the hip, disease duration, glucocorticoid treatment duration between patients with and without vertebral fractures were demonstrated. The present study indicated that disease duration, BMI, and the total hip BMD were independent risk factors for vertebral fractures in patients with glucocorticoid-induced osteoporosis.

Conclusions

Prolonged disease duration, low BMI, and low total hip BMD could be risk factors of vertebral fracture in patients on glucocorticoid treatment for rheumatological diseases.

Glucocorticoids Enhanced Osteoclast Autophagy Through the PI3K/Akt/mTOR Signaling Pathway

Autophagy is an evolutionarily conserved dynamic process and present in variety of cells at basal levels to maintain homeostasis and to promote cell survival in response to stresses. The early bone loss with excessive glucocorticoids (GCs) was reported to be related with the extension of the life span of osteoclasts. However, the connection between GCs induced bone loss and osteoclast autophagy remains to be elucidated. Autophagy was detected in a Dexamethasone (Dex) induced osteoporotic mice model and primary osteoclast cultures by autophagosome detection kit, and autophagy-related proteins were assayed by Western blotting and Immunostaining. The bone morphology was examined by micro-CT and TRAP staining. The trabecular bone micro-architecture was deteriorated, and the osteoclast number and spread area were increased in the Dex-treated mice compared with the control group (P < 0.01). Meanwhile, autophagy in pre-osteoclasts was increased in mice under Dex administration evidenced by the increased number of autophagosome and up-regulation of autophagy-related protein levels. Further, the enhanced autophagy under Dex treatment was verified in primary cultured osteoclasts, as shown by the increased levels of Beclin 1 and LC3-II/LC3-I and the autophagy complex formation members including Atg1, Atg13, and Atg7. However, the expressions of PI3K, p-Akt and p-mTOR in primary cultured osteoclasts were inhibited under Dex induced autophagy. Using the selective PTEN inhibitor SF1670 to activate the PI3K/Akt/mTOR pathway reversed this osteoclast autophagy under Dex treatment. Our study suggests that osteoclast autophagy was enhanced in glucocorticoids induced bone loss, and the PI3K/Akt/mTOR signaling pathway mediated the increased autophagy in primary cultured osteoclasts under glucocorticoids treatment.

Osteoporosis in Rheumatic Diseases

Osteoporosis is a chronic disease characterized by an increased risk of fragility fracture. Patients affected by rheumatic diseases are at greater risk of developing osteoporosis. The purpose of the present review is to discuss the pathogenesis, epidemiology, and treatment of osteoporosis in patients affected by rheumatic diseases with special focus for rheumatoid arthritis, psoriatic arthritis, spondyloarthritis, systemic lupus erythematosus, systemic sclerosis, vasculitides, Sjogren syndrome, and crystal-induced arthritis.