Glucocorticoid-induced osteoporosis: pathophysiology and therapy

FABP4 inhibition suppresses bone resorption and protects against postmenopausal osteoporosis in ovariectomized mice

Postmenopausal osteoporosis (PMOP) is a condition in women caused by estrogen deficiency, characterized by reduced bone mass and increased fracture risk. Fatty acid-binding protein 4 (FABP4), a lipid-binding protein involved in metabolism and inflammation, has emerged as a key regulator in metabolic disorders and bone resorption; however, its direct role in PMOP remains unclear. Here, we show that serum FABP4 levels in PMOP patients negatively correlate with bone mineral density, a trend also observed in ovariectomized mice. FABP4 promotes osteoclast formation and bone resorption without affecting osteoblast differentiation. The FABP4 inhibitor BMS309403 suppresses osteoclast differentiation by modulating calcium signaling and inhibiting the Ca2+-Calcineurin-NFATc1 pathway. Oral BMS309403 increases bone mineral density in ovariectomized mice, though less effectively than alendronate. Notably, bone-targeted delivery of BMS309403 achieves comparable efficacy to alendronate. In this work, we demonstrate that FABP4 is a critical mediator in PMOP and that its inhibition offers a promising therapeutic strategy.

Increased risk of osteoporotic fractures and osteoporosis in patients with Addison's disease in Sweden: A nationwide population-based cohort study

BACKGROUND

The risk of major osteoporotic fractures (MOFs) and osteoporosis in patients with autoimmune Addison's disease (AAD) is unclear.

OBJECTIVE

To investigate the risk of MOF in patients with AAD and the possible correlation with adrenal hormone replacement doses.

METHODS

Swedish national health registers were used to identify 1869 subjects with AAD and 16,844 matched controls. The primary outcome was MOF, and the secondary outcome was treatment with osteoporosis medications. Marginal Cox models were used to compare time-to-event outcomes. The study period spanned from 1 July 2005 until 31 December 2020. Individuals at risk were followed from inclusion until censored or the end of the study period.

RESULTS

A total of 77 patients with AAD (7.1/1000 person-years [PY]), and 387 matched controls (3.9/1000 PY) were diagnosed with MOF. The risk of MOF was higher in patients with AAD compared to matched controls, with an adjusted hazard ratio (aHR) of 1.82 (95% confidence interval [CI], 1.41-2.35) and increased in both male and female patients, with aHR of 2.51 (95% CI, 1.56-4.02) and 1.65 (95% CI, 1.22-2.24), respectively. Patients with AAD had an increased risk of treatment with osteoporosis medications: aHR 3.25 (95% CI, 2.71-3.99), compared to controls. No significant differences in MOF rates were observed between patients treated with intermediate or high doses of glucocorticoids compared to low doses (p = 0.967 and p = 0.580, respectively). Similarly, stratification by mineralocorticoid dose (<0.10 vs. ≥0.10 mg/day) showed no significant association regarding MOF (p = 0.915).

CONCLUSIONS

The risk of MOF is increased in patients with AAD without any apparent correlation to adrenal hormone replacement doses.

Treatment Considerations for Severe Osteoporosis in Older Adults

Osteoporosis, a chronic metabolic bone disease, increases the predisposition to fragility fractures and is associated with considerable morbidity, high health care cost as well as mortality. An elevation in the rate of incident fragility fractures will be observed proportional with the increase in the number of older people worldwide. Severe osteoporosis is currently defined as having a bone density determined by dual-energy X-ray absorptiometry that is more than 2.5 standard deviations (SD) below the young adult mean with one or more past fractures due to osteoporosis. Nutrition, physical activity and adequate vitamin D are essential for optimal bone strength throughout life. Hormone (oestrogen/sex steroid) status is also a major determinant of bone health. This review explores mechanisms involved in bone homeostasis, followed by the assessment and management of severe osteoporosis, including an overview of several treatment options in older people that range from anti-resorptive to anabolic therapies.

Molecular mechanisms and treatment strategies for estrogen deficiency-related and glucocorticoid-induced osteoporosis: a comprehensive review

Osteoporosis, a debilitating condition characterized by reduced bone mass and increased fracture risk, is notably influenced by estrogen deficiency and glucocorticoid treatment. This comprehensive review elucidates the molecular mechanisms underpinning estrogen deficiency-related osteoporosis (EDOP) and glucocorticoid-induced osteoporosis (GIOP). The role of estrogen in bone metabolism is critically examined, highlighting its regulatory effects on bone turnover and formation through various signaling pathways. Conversely, this review explores how glucocorticoids disrupt bone homeostasis, focusing on their impact on osteoclast and osteoblast function and the subsequent alteration of bone remodeling processes. The pathogenesis of both conditions is intertwined, with estrogen receptor signaling pathways and the role of inflammatory cytokines being pivotal in driving bone loss. A detailed analysis of pathogenetic and risk factors associated with EDOP and GIOP is presented, including lifestyle and genetic factors contributing to disease progression. Modern therapeutic approaches emphasize pharmacologic, non-pharmacologic, and herbal treatments for managing EDOP and GIOP. In summary, current therapeutic strategies highlight the efficacy and the safety of various interventions. This review concludes with future directions for research, suggesting a need for novel treatment modalities and a deeper understanding of the underlying mechanisms of osteoporosis. By addressing the multifaceted nature of EDOP and GIOP, this work aims to provide insights into developing targeted therapeutic strategies and improving patient outcomes in osteoporosis management.

Management of pharmacotherapy in lung transplant candidates

PURPOSE OF REVIEW

Lung transplantation is a common treatment for end-stage lung disease (ESLD). Patients present to lung transplantation evaluation on various medications that could impact their candidacy and posttransplant course. In this review, we will discuss pretransplant optimization of pharmacotherapy to minimize complications while waiting for transplant and increase posttransplant success. We will also discuss important considerations for posttransplant immunosuppression, antimicrobial prophylaxis, and complex drug interactions.

RECENT FINDINGS

Prior to lung transplantation, several medications should be optimized to promote posttransplant success including minimization of corticosteroids, opioids, and benzodiazepines. Lung transplantation candidates should be up to date on vaccinations. Most medications for ESLD are well tolerated to continue up until the point of transplant including antifibrotics, CFTR modulators, and pulmonary vasodilators. Mammalian target of rapamycin inhibitors and other immunosuppressants may need to be stopped or minimized before lung transplantation to minimize posttransplant infection and would healing complications. Medications that increase risk of posttransplant bleeding, thrombosis, or aspiration should be stopped prior to listing.

SUMMARY

In this article, we discuss management of pharmacotherapy for lung transplantation candidates to minimize posttransplant complications. Changes in medications for ESLD should be done cautiously to prevent worsening of native disease while waiting for lung transplantation.

Exacerbated hypercalcemia, nephrolithiasis, and renal impairment after vitamin D supplementation in granulomatous disease: a case report

BACKGROUND

The cosmetic industry is booming with unorthodox therapies aimed at improving the appearance of beauty and strength. One such therapy is self-administered, intramuscular injections of paraffin oil for the purpose of increasing presumed muscular size. Paraffin oil injections are becoming frequent among younger male individuals, who inject up to several liters in (primarily) the upper extremities. However, paraffin oil leads to the formation of granulomas, which are rich in macrophages with an upregulated extrarenal 1-hydroxylation. These macrophages will rapidly and unimpededly convert inactive vitamin D (25OHD2) to active vitamin D (1,25OH2D3), thereby causing significant hypercalcemia and derivative disease.

CASE PRESENTATION

In 2007, a Scandinavian male individual in his 20s had self-injected 1200 ml of paraffin oil into both biceps. Within 5 years, the oil had migrated and was then widely dispersed in his biceps and surrounding tissues, causing swelling and pain. By 2015, granulomas had formed at injection sites, and he was admitted to a hospital with severe hypercalcemia, which was managed with fluid therapy and slowly resolved. From 2015 to 2020, his calcium levels were intermittently elevated, and he experienced two episodes of nephrolithiasis requiring surgical intervention. In 2020, he was prescribed one dose oral vitamin D (6000 µg cholecalciferol) for suspected vitamin D deficiency based on a low serum 25OHD2. His episodic hypercalcemia increased, and he developed nephrolithiasis and exacerbated renal impairment.

CONCLUSION

Unlike most other patients with low 25(OH)D2, patients with granulomatous disease should not routinely receive vitamin D supplementation, as this may aggravate hypercalcemia and hypercalcuria, causing nephrolithiasis and renal impairment.

Impact of glucocorticoids on osteocytes and on the lacuno-canalicular system of maxillary and mandibular alveolar bone

In long bones, glucocorticoids are known to cause a decrease in bone formation and an increase in bone resorption, leading to a condition of osteoporosis also during growth. However, there are few studies on the effect of glucocorticoids on alveolar bone. The aim of the present study was to evaluate the impact of chronic administration of glucocorticoids on osteocytes and the lacuno-canalicular system of maxillary and mandibular alveolar bone in growing rats. Male Wistar rats were administered intramuscular dexamethasone (7 mg/kg b.w.) or saline solution once a week for 5 weeks. After euthanasia, mandibles and upper maxillae were resected and processed for micro-computed tomography, histological, and immunohistochemical evaluation. Glucocorticoids induced morphological changes in the lacuno-canalicular system and apoptosis of alveolar bone osteocytes and had no effect on SOST/sclerostin osteocyte expression. Our findings suggest that the deleterious effect of glucocorticoids on alveolar bone is associated with osteocyte apoptosis and lacuno-canalicular system changes, whereas Wnt/β catenin pathway regulation in osteocytes appears to play no significant role in the pathogenesis of glucocorticoid-induced bone loss.

Screening for endogenous hypercortisolism in patients with osteoporosis and fractures: why, when and how

Skeletal comorbidities are frequent and clinically relevant findings in Cushing's syndrome (CS) since an uncoupled suppressed bone formation and enhanced bone resorption leads to a marked skeletal damage with a rapid increase of fracture risk. Reduced Bone Mineral Density (BMD) has been consistently reported and osteopenia or osteoporosis are typical findings in patients with CS. Vertebral Fractures (VFs) are frequently reported and may occur even in patients with an only mild reduction of BMD. Since CS is diagnosed late due to often difficult biochemical and radiological confirmation as well as to signs and symptoms common in other much more frequent diseases an approach suggested for overcoming underdiagnosis is to screen patients with manifestations which may overlap with those of CS such as arterial hypertension, diabetes mellitus and osteoporosis. Our review will focus on the rationale and best practice for screening osteoporotic patients for CS.

Matrix Metalloproteinase-9 Enhances Osteoclastogenesis: Insights from Transgenic Rabbit Bone Marrow Models and In Vitro Studies

Osteoclastogenesis is tightly regulated by receptor activator of nuclear factor kappa-B ligand (RANKL) signaling, yet the role of matrix metalloproteinase-9 (MMP-9) in this process remains controversial. We established a high-yield osteoclastogenesis system using cryopreserved rabbit bone marrow cells (1 × 109 cells/femur) treated with Macrophage colony-stimulating factor (M-CSF) and RANKL. Bone marrow cells from MMP-9 transgenic rabbits (macrophage-specific overexpression) and MMP-9-transfected RAW264.7 macrophages were compared to wild-type controls. MMP-9 overexpression increased osteoclastogenesis 5.5-fold (20 ng/mL RANKL, * p < 0.01) while suppressing inflammatory cytokines (IL-1β, TNF-α). RAW264.7 macrophages stably transfected with human MMP-9 similarly exhibited reduced inflammatory cytokine levels and enhanced osteoclastogenesis. MMP-9 acts as a dual regulator of osteoclastogenesis and inflammation, suggesting therapeutic potential for osteoporosis management.

Osteoporosis and fractures in systemic vasculitides: a systematic review and meta-analysis

Background/aim

We performed a systematic review and meta-analysis of observational studies aimed at investigating the prevalence of osteoporosis and osteoporotic fractures in subjects affected by systemic vasculitides (SVs) as well as to explore their risk of osteoporosis and osteoporotic fractures when compared to healthy controls.

Methods

Scopus, Web of Science and PubMed were systematically searched from inception to February 2024 for observational studies investigating the prevalence of osteoporosis and fragility fractures in adults with SVs. In addition, when available, we assessed the odd ratios (OR) of prevalent osteoporosis and fragility fractures amongst subjects with SVs vs. healthy controls. Data from eligible studies were extracted, and meta-analysis was performed using a random effects model to obtain ORs with 95% confidence intervals (CIs). Subgroup analyses and meta-regressions were also performed. This study was registered in Open Science Framework (DOI: https://doi.org/10.17605/OSF.IO/3G7RJ).

Results

Forty studies with 23,358 individuals affected by SVs were included. The overall prevalence of osteoporosis and fragility fractures in the SV patients were respectively 14.64% (95%CI 12.21-18.89), and 17.08% (95%CI 11.42-24.78). The ORs for osteoporosis and fragility fractures in SV patients when compared with healthy controls were 2.92 (95%CI 1.72-4.98) and 2.39 (95%CI 1.34-4.26) respectively. The univariable meta-regression analysis showed a significant association between cumulative glucocorticoids' dosage (total grams) and risk of prevalent osteoporosis (estimate = 0.0995, R2 = 0.24, p=0.0194).

Conclusion

SVs are associated with an increased risk for osteoporosis and fragility fractures, suggesting that active vigilance and pre-emptive screening are recommended.

Systematic review registration

https://archive.org/details/osf-registrations-3g7rj-v1.

Bone Mineral Density Improvement After Resolution of Endogenous Cushing Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

We aimed to identify all evidence to evaluate bone mineral density (BMD) improvement after resolution of endogenous Cushing syndrome (eCS).

METHODS

Potentially eligible studies were identified from the EMBASE and PubMed databases from inception to February 2024, utilizing a search strategy incorporating terms related to "Bone mineral density" and "Cushing syndrome". Eligible studies must include patients diagnosed with eCS. These studies must present lumbar spine (LS) or femoral neck (FN) BMD measurements before and after resolution of eCS. Point estimates with standard errors were extracted from each study and combined using the generic inverse variance method. Meta-regression analysis was utilized to explore factors influencing BMD improvement.

RESULTS

After systematic review, 5085 records were identified. After systematic review, 12 studies (302 patients, mean age of 13-44 years, % female patients 57%-92%, follow-up time 16-60 months) were eligible. The meta-analysis demonstrated that resolution of eCS resulted in improvements in LS BMD (pooled mean difference T-score: +0.86, I2 80.4%; 95%CI 0.51-1.21; Z-score: +0.86, 95%CI 0.57-1.16, I2 75.9%) and FN BMD (pooled mean difference: T-score: +0.38, 95%CI 0.26-0.51, I2 0.0%; Z-score: +0.44, 95%CI 0.31-0.57, I2 20.3%). The meta-regression analysis identified factors potentially influencing LS BMD increases, including longer follow-up time, higher %female patients and lower mean baseline 24-hour UFC, while none of these factors were significantly associated with FN BMD changes.

CONCLUSION

Our study presents the degree and influencing factors of BMD improvement following eCS resolution. These findings offer guidance for management of eCS-associated osteoporosis.

Differences in bone turnover markers and injury risks between local and international horses: A Victorian Spring Racing Carnival study

BACKGROUND

Musculoskeletal injuries (MSI) are common in racehorses and have been of increasing concern in horses travelling internationally to compete. Understanding the differences in bone turnover between local horses and international horses following long-distance air transportation may inform MSI prevention strategies.

OBJECTIVES

To understand the differences in bone turnover markers and risk of MSI between local horses and international horses following long-distance air transportation.

STUDY DESIGN

Prospective cohort.

METHODS

The concentrations of bone turnover markers (OCN and CTXI), markers of stress (cortisol), inflammation (serum amyloid A) and circadian rhythm (melatonin), and bisphosphonates were determined in blood samples collected twice (14-17 days apart), from horses following international travel (n = 69), and from local horses (n = 79). The associations between markers, long-distance travel and MSI were determined using multivariable generalised linear regression models.

RESULTS

Within 3-5 days post-transport, concentrations of cortisol in international horses were higher than those of local horses (main effect, Coef. 0.39; 95% CI 0.24, 0.54; p < 0.001) but they decreased and were not different to those of local horses at the second timepoint (interaction effect, Coef. -0.27; 95% CI -0.46, -0.07; p = 0.007). After adjusting for age and sex, OCN and CTXI were not significantly different between international and local horses; however, OCN was lower in international horses at timepoint 2 (interaction effect, Coef. -0.16; 95% CI -0.31, -0.01; p = 0.043). The prevalence of MSI was higher in the international (26%; 95% CI 16, 38%) compared with local horses (8%; 95% CI 3, 16%; p < 0.001), with all severe MSI sustained by the international horses. At the second timepoint compared with the first timepoint post-transport, cortisol remained high or increased (interaction effect, Coef. 0.43; 95% CI 0.24, 0.61; p < 0.001) and OCN increased (interaction effect, Coef. 0.26; 95% CI 0.08, 0.44; p = 0.006) in the horses that sustained severe MSI.

MAIN LIMITATIONS

Horse population and racing career parameters differed between groups. Bone turnover markers have low sensitivity to detect local bone changes.

CONCLUSIONS

Most horses showed minimal effects of long-distance air transport within 2 weeks relative to local horses as assessed by stress and bone turnover markers. Screening for persistent high cortisol and evidence of net bone formation after long-distance air transportation may help to identify racehorses at high risk of catastrophic MSI.

Glucocorticoids Alter Bone Microvascular Barrier via MAPK/Connexin43 Mechanisms

Glucocorticoids (GCs) are standard-of-care treatments for inflammatory and immune disorders, and their long-term use increases the risk of osteoporosis. Although GCs decrease bone functionality, their role in bone microvasculature is incompletely understood. Herein, the study investigates the mechanisms of bone microvascular barrier function via osteoblast-endothelial interactions in response to GCs. The animal data shows that prednisolone (Psl) downregulated the osteoblast function and microvessel number and size. To investigate the role of GCs in bone endothelial barrier function further, a bicellular microfluidic in vitro system is developed and utilized, which consists of three-dimensional (3D) perfusable microvascular structures embedded in collagen I/osteoblast matrix. Interestingly, it is demonstrated that GCs significantly inhibit osteogenesis and microvascular barrier function by interfering with endothelial-osteoblast interactions. This effect is triggered by MAPK-induced phosphorylation of connexin43 (Cx43) at Ser282. Collectively, this study sheds light on microvascular function in bone disorders, as osteoporosis, and permits to capture dynamic changes in endothelial-bone interactions under GCs by dissecting the MAPK/Cx43 mechanism and proposing this as a potential target for bone diseases.

Metabolic musculoskeletal disorders in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is a chronic inflammatory disorder that affects not only the gastrointestinal tract but also extraintestinal organs, leading to various extraintestinal manifestations and complications. Among these, musculoskeletal disorders such as osteoporosis, sarcopenia, and axial and peripheral spondyloarthritis are the most commonly observed. These conditions arise from complex mechanisms, including chronic inflammation, malnutrition, gut dysbiosis, and glucocorticoid use, all of which contribute to reduced bone density, muscle loss, and joint inflammation. Osteoporosis and sarcopenia may co-occur as osteosarcopenia, a condition that heightens the risk of fractures, impairs physical performance, and diminishes quality of life, particularly in elderly patients with IBD. Holistic management strategies, including lifestyle modifications, calcium, and vitamin D supplementation, resistance training, and pharmacological interventions, are essential for mitigating the impact of these conditions. Spondyloarthritis, which affects both axial and peripheral joints, further complicates disease management and significantly compromises joint health. Timely diagnosis and appropriate medical interventions, such as administration of nonsteroidal anti-inflammatory drugs and biologics, are critical for preventing chronic joint damage and disability. Moreover, a multidisciplinary approach that addresses both metabolic and inflammatory aspects is essential for optimizing physical function and improving treatment outcomes in patients who have IBD with musculoskeletal involvement.

Recent Advances in the Etiology, Diagnosis, and Treatment of Marmoset Wasting Syndrome

One of the primary challenges encountered in managing captive callitrichids is a group of gastrointestinal disorders that are collectively known as Marmoset Wasting Syndrome (MWS). Unfortunately, MWS is still not well understood. It is suggested that MWS has a multifactorial etiology; stress, infection, malnutrition, malabsorption, and enteritis or colitis may be associated with MWS. Usually, animals demonstrate more than one of the following clinical signs: progressive weight loss, alopecia, chronic diarrhea, muscle atrophy, hypoproteinemia, and anemia. Recent advances in diagnostics, mostly noninvasive fecal and urine tests, yielded promising results. Good treatment results have been achieved with the administration of glucocorticoids and tranexamic acid, although no cure has been found yet. Probiotics and gel diets also demonstrated to be potentially useful. However, once animals are affected by MWS, treatments eventually become ineffective, and animals will inevitably require euthanasia to prevent further suffering. Preventative measures should be aimed at reducing stress and optimizing housing, husbandry, and diets. More research is warranted to elucidate the pathogenesis of MWS in captive callitrichids and to refine diagnostic and treatment methods.

Mild autonomous cortisol secretion: impact on bone health and quality of life. A review

INTRODUCTION

Mild autonomous cortisol secretion (MACS) is associated with several cardiometabolic and non-metabolic comorbidities, including osteoporosis, fractures and worse quality of life (QoL).

METHODS

We performed a comprehensive review of the literature including articles that reported the association between MACS and osteoporosis, fractures and impact on QoL.

RESULTS

In relation to bone health, several studies reported that the risk of fractures in patients with MACS is discordant with the degree of bone mineral density loss measured per dual X-ray absorptiometry (DXA), suggesting that a reduction in bone quality rather than density contributes to the increased fracture risk. Nevertheless, in general a greater prevalence of vertebral fractures has been described in MACS compared with nonfunctioning adrenal incidentalomas (NFAIs) patients. Regarding QoL, due to the higher burden of comorbidities and the adverse symptoms linked to MACS diagnosis, MACS patients are overall frailer and have worse QoL than patients with NFAIs or the general population. Higher levels of disability related to mental health, middle insomnia and perceived stress have also been described in patients with MACS when compared to NFAIs patients.

CONCLUSION

MACS patients have a higher prevalence of fractures and osteoporosis, as well as a worse QoL compared to NFAIs and the general population. Thus, both bone health and QoL evaluation should be part of the assessment of patients with MACS diagnosis.

Endocrine and metabolic comorbidities in juvenile-onset systemic lupus erythematosus

Background and aims

Juvenile-onset systemic lupus erythematosus (JSLE) is a chronic autoimmune disease affecting individuals under 18, causing multi-system impairment. Patients with JSLE exhibit more severe disease when compared to patients with adult-onset SLE. This study aimed to evaluate the prevalence of endocrine and metabolic comorbidities in patients with JSLE, and analyze the factors associated with each comorbidity.

Methods

Anthropometric, clinical, laboratory data, and the details of glucocorticoids and disease-modifying anti-rheumatic drugs use were collected.

Results

A total of 57 patients with JSLE (48 girls and 9 boys) were included in this study. Endocrine and metabolic comorbidities were observed in 64.9% of the patients. The most prevalent comorbidities were dyslipidemia (40.4%), being overweight or obese (26.3%), subclinical hypothyroidism (24.6%), autoimmune thyroid disease (AITD) (21.1%), and low bone mass (20.9%). The risk of dyslipidemia and AITD increased in patients who were overweight or obese. The risk of being overweight or obese was associated with skin involvement at diagnosis and rheumatoid factor positivity. Younger age at diagnosis and longer duration of glucocorticoid exposure increased the risk of low bone mass. The overall prevalence of endocrine and metabolic comorbidities was associated with short stature at diagnosis, being overweight or obese at follow-up, skin involvement at diagnosis, and rheumatoid factor positivity.

Conclusion

Patients with JSLE have higher burdens of endocrine and metabolic comorbidities and should be routinely monitored. Prevention of obesity may be helpful in lowering the risk of comorbidities.

Relationship Among Fragility Fractures and the Overall Cardiovascular Burden in Endogenous Cushing Syndrome

Context

Patients with endogenous Cushing syndrome (CS), in addition to significant cardiovascular morbidity, are burdened by a high prevalence of fragility fractures. Bone mineral density (BMD) alone poorly predicts the risk of fracture, and the implementation of trabecular bone score (TBS) is supported only by scant evidence. Indeed, reliable predictors of fractures in endogenous CS are still lacking.

Objective

This work aimed to analyze the prevalence and the potential predictors of fragility fractures in our patients with CS.

Methods

A monocentric, retrospective, cross-sectional study. A total of 51 patients with overt CS were enrolled. Main outcome measures included biochemical evaluation, BMD measurement, TBS evaluation, fracture presence, body composition evaluation, and arterial intima-media thickness (IMT) assessment.

Results

Fragility fractures were found in 62.7% of patients at diagnosis. Fractured patients exhibited lower spine T-score (P = .03), longer disease duration (P = .025), higher waist circumference (P = .006), and predominantly male sex (P = .008). Increased serum uric acid levels (P = .001), greater IMT (P = .017), and higher prevalence of venous thromboembolism events (31.3% vs 5.3%, P = .037) and atherosclerotic plaques (47% vs 5.3%, P = .002) were described in the fracture group.Multivariable logistic regression identified the presence of atherosclerosis (OR 13.35; 95% CI 1.154-154.34, P = .038) and osteoporosis (OR 11.30; 95% CI 1.55-82.56, P = .017) as independent predictors. TBS values were inversely correlated with body mass index, fat and lean mass, and serum uric acid, and positively correlated with high-density lipoprotein cholesterol.

Conclusion

CS patients with higher overall burden of cardiovascular morbidity are more prone to experience fragility fractures.

Epidural steroid injections and fracture incidence among older individuals with radiculopathy

Epidural steroid injections (ESIs) are a common and often effective treatment for radicular back pain. While oral glucocorticoids increase fracture incidence, little is known regarding fracture risk after ESI. This study investigated the incidence of fractures among individuals who received ESI and those who did not. We hypothesized that ESI exposure would be associated with an increased incidence of osteoporotic fractures and specifically vertebral fractures. Using 2005-2018 5% Medicare data, individuals with radicular pain who had ≥1 ESI and those who did not (non-ESI) were matched 1:10 by age, sex, and month of radicular pain diagnosis using exposure density sampling (EDS). Using a high-dimensional propensity score (HDPS) calculated based on the top 500 covariates across multiple data dimensions, ESI and non-ESI individuals were matched 1:1. Fractures were identified using validated ICD-9/10 diagnosis codes. Fracture incidence rate (IR) was calculated by group, and hazard ratios (HR) compared using Cox regression. 25 062 ESI patients and 221 735 non-ESI patients who met eligibility criteria were identified using EDS. Mean age was 76 yr (74% female). Among ESI-treated individuals, there were 2296 fractures, IR 49.1 (95% CI: 47.2-51.2) per 1000 person yr. For non-ESI individuals, there were 11 917 fractures, IR 35.2 (95% CI: 34.5-35.8). Individuals who received ESI had a greater hazard of fracture at typical osteoporotic sites, HR 1.39 (95% CI 1.33-1.46) by EDS and 1.32 (1.12-1.54) by HDPS, and a greater hazard of vertebral fracture, 1.54 (1.45-1.64) by EDS and 1.69 (1.38-2.07) by HDPS. Patients who received greater cumulative ESI doses (≥3 in 1 yr) had a higher risk of fractures within the first 6 mo of follow-up. ESI exposure in older individuals is associated with an increased risk of fracture, suggesting there may be lasting detrimental skeletal effects of ESI. Further research into strategies to reduce fracture risk in this population is warranted.

Anti-Osteoporosis Is Imperative in Prevention of Progress of Ankylosing Spondylitis

Background

Ankylosing spondylitis (AS) is a chronic autoimmune disease that affects the spine and peripheral joints, often leading to kyphosis, joint stiffness, and even ankylosis. Sagittal parameters, such as total thoracic kyphosis (TTK), thoracic kyphosis (TK), major thoracic kyphosis (MTK), and thoracolumbar kyphosis (TLK), are crucial indices for evaluating spinal alignment in AS patients and can reflect disease progression. This study aims to explore the relationship between bone mineral density (BMD), sagittal parameters, and joint ankylosis in AS patients.

Methods

A retrospective study was conducted on 147 AS patients. Participants were divided into three groups based on cervical and hip joint mobility. BMD was measured using quantitative computed tomography (QCT). Sagittal parameters (TTK, TK, MTK, TLK) were assessed using X-rays. Ordinal multinomial logistic regression and Spearman correlation analyses were performed to identify factors influencing joint stiffness.

Results

Significant differences in age, BMD, and sagittal parameters (TTK, TK, MTK, TLK) were observed among the groups. Ordinal logistic revealed that BMD (Estimate = 0.012) was negatively correlated with joint stiffness, while TTK (Estimate = 0.020) and TLK (Estimate = 0.030) were positively correlated. Age, TK, and MTK do not have a significant impact on joint stiffness. Spearman analysis showed no correlation between BMD and sagittal parameters (TTK and TLK). Besides, TTK and TLK were correlated.

Conclusion

In AS patients, BMD is an independent protective factor against joint stiffness, whereas sagittal parameters (TTK and TLK) contribute to increased joint stiffness. These findings highlight the importance of monitoring both bone mineral density and key sagittal parameters in clinical practice. Early anti-osteoporosis treatment, alongside interventions targeting abnormal spinal alignment, may help preserve joint mobility and potentially prevent progression to joint ankylosis.

Investigating the preventive effects of pulsed electromagnetic fields on glucocorticoid-induced osteoporosis in rats

The use of pulsed electromagnetic field (PEMF) has demonstrated effectiveness in the management of femoral head osteonecrosis as well as nonunion fractures; however, the effects of PEMF on preventing glucocorticoid-induced osteoporosis (GIOP) have not been extensively studied. The aim of this investigation was to explore the effectiveness of PEMF stimulation in averting GIOP in rats and uncover the potential fundamental mechanisms involved. A total of seventy-two adult male Wistar rats composed the experimental group and were subsequently assigned to three groups for treatment. (1) On the first day (day 0), 24 rats in the PEMF group were intravenously injected with lipopolysaccharide (LPS) at a concentration of 10 μg/kg. This was followed by intramuscular injections of methylprednisolone acetate (MPSL) at a dose of 20 mg/kg for the subsequent three days (days 1-3). Subsequently, the rats were exposed to PEMF for 4 h daily, with the duration varying from 1 to 8 weeks. (2) Adhering to the injection schedule of the PEMF group, the MPSL group (consisting of 24 rats) was administered LPS and MPSL, omitting PEMF stimulation. (3) The PS group (n = 24) was administered injections of 0.9% saline solution in an identical manner and at the same time intervals as the other two groups. At 1, 2, 4, and 8 weeks after the last MPSL (or saline) injection, bone mineral density (BMD), bone mineral content (BMC), and the expression levels of bone morphogenetic protein-2 (BMP-2) mRNA and protein in the proximal femur were measured. Analysis of the PS and PEMF groups at 1, 2, 4, and 8 weeks after the final saline (or MPSL) injection revealed no statistically significant differences in BMD or BMC (P > 0.05). From weeks 2 through 8, the MPSL group rats displayed a marked decrease in BMD and BMC compared to those of the PS group, and at the 4-week and 8-week time points, these values were significantly lower than those of the PEMF group (P < 0.05). Compared with those in the MPSL and PS groups, the expression levels of BMP-2 mRNA markedly increased after PEMF treatment, peaking one week later and sustaining a heightened state for four weeks, but decreased only at the eighth week. Conversely, BMP-2 protein expression exhibited a similar upward trend, peaking two weeks after PEMF treatment and then remaining elevated for the subsequent eight weeks. PEMF stimulation has been shown to have prophylactic potential against GIOP in rats, possibly through the upregulation expression of BMP-2 expression.

Tau is a receptor with low affinity for glucocorticoids and is required for glucocorticoid-induced bone loss

Glucocorticoids (GCs) are the most prescribed anti-inflammatory and immunosuppressive drugs. However, their use is often limited by substantial side effects, such as GC-induced osteoporosis (GIO) with the underlying mechanisms still not fully understood. In this study, we identify Tau as a low-affinity binding receptor for GCs that plays a crucial role in GIO. Tau deficiency largely abolished bone loss induced by high-dose dexamethasone, a synthetic GC, in both inflammatory arthritis and GIO models. Furthermore, TRx0237, a Tau inhibitor identified from an FDA-approved drug library, effectively prevented GIO. Notably, combinatorial administration of TRx0237 and dexamethasone completely overcame the osteoporosis adverse effect of dexamethasone in treating inflammatory arthritis. These findings present Tau as a previously unrecognized GC receptor with low affinity, and provide potential strategies to mitigate a spectrum of GC-related adverse effects, particularly osteoporosis.

Polyphenols and Functionalized Hydrogels for Osteoporotic Bone Regeneration

Osteoporosis induces severe oxidative stress and disrupts bone metabolism, complicating the treatment of bone defects. Current therapies often have side effects and require lengthy bone regeneration periods. Hydrogels, known for their flexible mechanical properties and degradability, are promising carriers for drugs and bioactive factors in bone tissue engineering. However, they lack the ability to regulate the local pathological environment of osteoporosis and expedite bone repair. Polyphenols, with antioxidative, anti-inflammatory, and bone metabolism-regulating properties, have emerged as a solution. Combining hydrogels and polyphenols, polyphenol-based hydrogels can regulate local bone metabolism and oxidative stress while providing mechanical support and tissue adhesion, promoting osteoporotic bone regeneration. This review first provides a brief overview of the types of polyphenols and the mechanisms of polyphenols in facilitating adhesion, antioxidant, anti-inflammatory, and bone metabolism modulation in modulating the pathological environment of osteoporosis. Next, this review examines recent advances in hydrogels for the treatment of osteoporotic bone defects, including their use in angiogenesis, oxidative stress modulation, drug delivery, and stem cell therapy. Finally, it highlights the latest research on polyphenol hydrogels in osteoporotic bone defect regeneration. Overall, this review aims to facilitate the clinical application of polyphenol hydrogels for the treatment of osteoporotic bone defects.

Skeletal fragility in pituitary disease: how can we predict fracture risk?

Pituitary hormones play a crucial role in regulating skeletal physiology, and skeletal fragility is a frequent complication of pituitary diseases. The ability to predict the risk of fracture events is crucial for guiding therapeutic decisions; however, in patients with pituitary diseases, fracture risk estimation is particularly challenging. Compared to primary osteoporosis, the evaluation of bone mineral density by dual X-ray absorptiometry is much less informative about fracture risk. Moreover, the reliability of standard fracture risk calculators does not have strong validations in this setting. Morphometric vertebral assessment is currently the cornerstone in the assessment of skeletal fragility in patients with pituitary diseases, as prevalent fractures remain the strongest predictor of future fracture events. In recent years, new tools for evaluating bone quality have shown promising results in assessing bone impairment in patients with pituitary diseases, but most available data are cross-sectional, and evidence regarding the prediction of incident fractures is still scarce. Of note, apart from measures of bone density and bone quality, the estimation of fracture risk in the context of pituitary hyperfunction or hypofunction cannot ignore the evaluation of factors related to the underlying disease, such as its severity and duration, as well as the specific therapies implemented for its treatment. Aim of this review is to provide an up-to-date overview of all major evidence regarding fracture risk prediction in patients with pituitary disease, highlighting the need for a tailored approach that critically integrates all clinical, biochemical, and instrumental data according to the specificities of each disease.

Progression of vertebral fractures in metastatic melanoma and non-small cell lung cancer patients given immune checkpoint inhibitors

Introduction

The immune system mediates important effects on bone metabolism, but little has been done to understand immunotherapy's role in this interaction. This study aims to describe and identify risk factors for the occurrence and/or exacerbation of vertebral fractures (vertebral fracture progression) during immune checkpoint inhibitors (ICIs).

Methods

We conducted an observational, retrospective, monocentric study. We collected data on melanoma and NSCLC patients, treated with first-line ICIs at the Medical Oncology Department ASST Spedali Civili of Brescia, between January 2015 and November 2021, and with a median follow-up of 20.1 (6-36) months. We collected data on patients, diseases, immune-related adverse events, and cortico-steroid therapy initiated on concomitant ICIs.

Results

We identified 135 patients, 65 (48.2 %) with locally advanced/metastatic melanoma and 70 (51.8 %) with locally advanced/metastatic non-small cell lung cancer (NSCLC). Twenty-one (15.6 %) patients already had an asymptomatic vertebral fracture at baseline before starting ICIs in monotherapy. A total of ten patients, or 7.4 %, had a vertebra fracture progression defined as a new vertebral fracture or a worsening of a previous fracture. There was a strong relation between the steroid therapy and irAEs with vertebra fracture progression [OR (95 % CI) 8.1 (3.7-17.8) p-value < 0.001] in univariable analysis. However, only steroid therapy resulted to be an independent risk factor [8.260 (95 % CI 0.909-75.095); p-value 0.061] at the multivariable analysis.

Conclusion

Concurrent steroid therapy in patients receiving immunotherapy exposes them to a high risk of fractures due to skeletal fragility. The use of bone resorption inhibitors should be considered in these patients to prevent these adverse events.

Vitamin D in pituitary driven osteopathies

The evidence that pituitary hormones may bypass peripheral endocrine glands to exert remarkable effects on the skeleton is gaining ground. Both hormonal excess and deficit may determine impairment in bone structure, and they commonly result in bone loss in patients affected by pituitary and neuroendocrine disorders. Vertebral fractures are the most common skeletal alterations and may occur independently of bone mass. Use of vitamin D (VD) supplementation is still debated in this setting. This review will focus on the interactions between different metabolites of VD and pituitary hormones, and the effects of VD supplementation on bone metabolism in patients with pituitary diseases.

Generation of BT-Amide, a Bone-Targeted Pyk2 Inhibitor, Effective via Oral Administration, for the Prevention of Glucocorticoid-Induced Bone Loss

Glucocorticoid-induced osteoporosis (GIOP) is the leading cause of iatrogenic osteoporosis due to the widespread clinical use of glucocorticoids (GC) as immunosuppressants. Previous research identified the proline-rich tyrosine kinase 2, Pyk2, as a critical mediator of GC-induced bone loss, and that blocking Pyk2 could protect the skeleton from adverse GC actions. However, systemic administration of current Pyk2 inhibitors causes harmful side effects, such as skin lesions. To address this, we developed bone-targeted (BT) Pyk2 inhibitors by conjugating them with bisphosphonates (BP), ensuring adherence to the bone matrix and reducing impact on noncalcified tissues. We synthesized BT-Amide by linking a derivative of TAE-226, a Pyk2 inhibitor, with alendronic acid. Oral administration (gavage) of BT-Amide prevented GC-induced bone loss in mice without causing skin lesions, or elevation of any organ toxicity markers. These findings introduce BT-Amide as the first orally effective bone-targeted Pyk2 inhibitor for preventing GC-induced bone loss while minimizing off-target effects.

Beyond the Surface: Uncovering Secondary Causes of Osteoporosis for Optimal Management

Osteoporosis (OP), a condition marked by reduced bone mineral density and increased fracture risk, can arise either as a primary disorder or secondary to other diseases and medications. While primary OP typically relates to age-related or postmenopausal changes, secondary OP results from underlying conditions or drug exposures, complicating diagnosis and management. This review explores the pathophysiology, prevalence, and treatment approaches for secondary OP arising from endocrine, renal, gastrointestinal, hematological, and autoimmune disorders, as well as medication side effects. The findings highlight that secondary OP is frequently undiagnosed, particularly in premenopausal women and men, with conditions such as chronic kidney disease, glucocorticoid use, and diabetes among the primary contributors. Management strategies must be tailored to address the underlying conditions to effectively reduce fracture risk and improve outcomes. Ultimately, this review underscores the necessity for increased clinical awareness and more targeted interventions for optimal management of secondary OP.

Neuroprotective macromolecular methylprednisolone prodrug nanomedicine prevents glucocorticoid-induced muscle atrophy and osteoporosis in a rat model of spinal cord injury

To address the adverse side effects associated with systemic high-dose methylprednisolone (MP) therapy for acute spinal cord injury (SCI), we have developed a N-2-hydroxypropyl methacrylamide copolymer-based MP prodrug nanomedicine (Nano-MP). Intravenous Nano-MP selectively targeted to the inflamed SCI lesion and significantly improved neuroprotection and functional recovery after acute SCI. In the present study, we comprehensively assessed the potential adverse side effects associated with the treatment in the SCI rat models, including reduced body weight and food intake, impaired glucose metabolism, and reduced musculoskeletal mass and integrity. In contrast to free MP treatment, intravenous Nano-MP after acute SCI not only offered superior neuroprotection and functional recovery but also significantly mitigated or even eliminated the aforementioned adverse side effects. The superior safety features of Nano-MP observed in this study further confirmed the clinical translational potential of Nano-MP as a highly promising drug candidate for better clinical management of patients with acute SCI.

Therapeutic Potential of Stearoyl-CoA Desaturase1 (SCD1) in Modulating the Effects of Fatty Acids on Osteoporosis

Osteoporosis is a common skeletal disease, primarily associated with aging, that results from decreased bone density and bone volume. This reduction significantly increases the risk of fractures in osteoporosis patients compared to individuals with normal bone density. Additionally, the bone regeneration process in these patients is slow, making complete healing difficult. Along with the decline in bone volume and density, osteoporosis is characterized by an increase in marrow adipose tissue (MAT), which is fat within the bone. In this altered bone microenvironment, osteoblasts are influenced by various factors secreted by adipocytes. Notably, saturated fatty acids promote osteoclast activity, inhibit osteoblast differentiation, and induce apoptosis, further reducing osteoblast formation. In contrast, monounsaturated fatty acids inhibit osteoclast formation and mitigate the apoptosis caused by saturated fatty acids. Leveraging these properties, we aimed to investigate the effects of overexpressing stearoyl-CoA desaturase 1 (SCD1), an enzyme that converts saturated fatty acids into monounsaturated fatty acids, on osteogenic differentiation and bone regeneration in both in vivo and in vitro models. Through this novel approach, we seek to develop a stem cell-based therapeutic strategy that harnesses SCD1 to improve bone regeneration in the adipocyte-rich osteoporotic environment.

Fluid shear stress-mediated Piezo1 alleviates osteocyte apoptosis by activating the PI3K/Akt pathway

Glucocorticoid-induced osteoporosis serves as a primary cause for secondary osteoporosis and fragility fractures, representing the most prevalent adverse reaction associated with prolonged glucocorticoid use. In this study, to elucidate the impact and underlying mechanisms of fluid shear stress (FSS)-mediated Piezo1 on dexamethasone (Dex)-induced apoptosis, we respectively applied Dex treatment for 6 h, FSS at 9 dyne/cm2 for 30 min, Yoda1 treatment for 2 h, and Piezo1 siRNA transfection to intervene in MLO-Y4 osteocytes. Western blot analysis was used to assess the expression of Cleaved Caspase-3, Bax, Bcl-2, and proteins associated with the PI3K/Akt pathway. Additionally, qRT-PCR was utilized to quantify the mRNA expression levels of these molecules. Hoechst 33258 staining and flow cytometry were utilized to evaluate the apoptosis levels. The results indicate that FSS at 9 dyne/cm2 for 30 min significantly upregulates Piezo1 in osteocytes. Following Dex-induced apoptosis, the phosphorylation levels of PI3K and Akt are markedly suppressed. FSS-mediated Piezo1 exerts a protective effect against Dex-induced apoptosis by activating the PI3K/Akt pathway. Additionally, downregulating the expression of Piezo1 in osteocytes using siRNA exacerbates Dex-induced apoptosis. To further demonstrate the role of the PI3K/Akt signaling pathway, after intervention with the PI3K pathway inhibitor, the activation of the PI3K/Akt pathway by FSS-mediated Piezo1 in osteocytes was significantly inhibited, reversing the anti-apoptotic effect. This study indicates that under FSS, Piezo1 in MLO-Y4 osteocytes is significantly upregulated, providing protection against Dex-induced apoptosis through the activation of the PI3K/Akt pathway.

The association between myasthenia gravis and risk of fracture: a systematic review and meta-analysis

Patients with myasthenia gravis (MG), because of their muscle weakness and exposure to corticosteroids treatment, are generally considered to be at increased risk for osteoporosis or fracture. However, clinical evidence of this issue is lacking. In this review, we systematically searched databases, including Cochrane Library, PubMed, Embase, and Airiti library from inception to the end of November 2023 for cohort studies that compared participants with MG and participants without MG for incidence of osteoporosis or fracture. We used the Newcastle-Ottawa Scale for quality assessment. In total, we included 3 studies with 34,865 participants. The pooled meta-analysis using the random effect model demonstrated no significant difference in risk of fracture in the MG group (odds ratio = 1.52; 95% confidence interval = 0.74 to 3.12; I2 = 93%; between-study variance [τ2] = 0.32) compared with that for the non-MG group. Due to limited studies, we could not perform a quantitative analysis for risk of osteoporosis. In conclusion, we found no robust evidence to support the proposition that patients with MG are at higher risk for fracture than general comparators. The explanations and underlying mechanisms of this finding remain unclear, we therefore conclude that additional studies are warranted.

The comprehensive incidence and risk factors of fracture in kidney transplant recipients: A meta-analysis

AIM

Kidney transplant recipients are at high risk of fracture due to many factors such as nutritional status, hyperparathyroidism, acidosis and steroid administration. The current meta-analysis aimed to comprehensively analyse the incidence and risk factors of fracture in kidney transplant recipients.

METHODS

A systematic search on Embase, Web of Science, PubMed and Cochrane Library until November 2023 was performed. RStudio software was used to analyse data.

RESULTS

Twenty-eight eligible studies containing 310 530 kidney transplant recipients were included in the analysis. The pooled incidence of fracture was 10% (95% confidence interval [CI]: 7%-13%) generally. When divided by regions, it was further observed that the pooled incidence of fracture was 13% (95% CI: 9%-17%) in Europe, 11% (95% CI: 6%-16%) in North America, 7% (95% CI: 3%-11%) in Asia. Regarding the risk factors, pooled analysis revealed that age of recipient (hazard ratio [HR] = 1.50, 95% CI: 1.17-1.91), female sex (HR = 1.45, 95% CI: 1.36-1.53), pretransplantation diabetes (HR = 1.76, 95% CI: 1.58-1.97), pretransplantation fracture history (HR = 2.28, 95% CI: 1.86-2.78), dialysis duration (HR = 1.09, 95% CI: 1.01-1.17) and deceased donor (HR = 1.21, 95% CI: 1.05-1.39) related to higher risk of fracture. The general quality of included studies was acceptable, and no publication bias existed except for the analysis between age of recipient and fracture incidence; further trim and fill method indicated age of recipient showed a correlation trend with the fracture incidence without the statistical significance.

CONCLUSION

The pooled incidence of fracture reaches 10% in kidney transplant recipients, which relates to age of recipient, female sex, pretransplantation diabetes or fracture history, dialysis duration and decease donor.

An Osteoimmunomodulatory Biopatch Potentiates Stem Cell Therapies for Bone Regeneration by Simultaneously Regulating IL-17/Ferroptosis Signaling Pathways

Currently, there are still great challenges in promoting bone defect healing, a common health problem affecting millions of people. Herein an osteoimmunity-regulating biopatch capable of promoting stem cell-based therapies for bone regeneration is developed. A totally biodegradable conjugate is first synthesized, which can self-assemble into bioactive nano micelles (PPT NMs). This nanotherapy effectively improves the osteogenesis of periodontal ligament stem cells (PDLSCs) under pathological conditions, by simultaneously regulating IL-17 signaling and ferroptosis pathways. Incorporation of PPT NMs into biodegradable electrospun nanofibers affords a bioactive patch, which notably improves bone formation in two rat bone defect models. A Janus bio patch is then engineered by integrating the bioactive patch with a stem cell sheet of PDLSCs. The obtained biopatch shows additionally potentiated bone regeneration capacity, by synergistically regulating osteoimmune microenvironment and facilitating stem cell differentiation. Further surface functionalization of the biopatch with tannic acid considerably increases its adhesion to the bone defect, prolongs local retention, and sustains bioactivities, thereby offering much better repair effects in rats with mandibular or cranial bone defects. Moreover, the engineered bioactive patches display good safety. Besides bone defects, this osteoimmunity-regulating biopatch strategy can be applied to promote stem cell therapies for spinal cord injury, wound healing, and skin burns.

Fufang Zhenshu Tiaozhi capsule enhances bone formation and safeguards against glucocorticoid-induced osteoporosis through innovative Mekk2-mediated β-catenin deubiquitination

INTRODUCTION

Bone homeostasis depends on the regulation of β-catenin in osteoblasts. Glucocorticoids (GCs) are known to diminish β-catenin activity via Wnt pathway signaling, leading to osteoporosis. Conversely, activating β-catenin in osteoblasts through mitogen-activated protein kinase kinase kinase 2 (Mekk2) offers an innovative approach to combat GC-induced osteoporosis (GIOP). Fufang Zhenshu Tiaozhi (FTZ) capsules have shown effectiveness in treating GIOP, but the mechanisms behind this are still unclear.

MATERIALS AND METHODS

In this study, Mekk2 knockout mice (Mekk2-/-) was generated by CRISPR/Cas9. These mice were then subjected to Alcian Blue-Alizarin Red staining and immunofluorescence to assess their bone and cartilage development. To establish models of GIOP, both Mekk2-/- and wild-type (WT) mice were treated with dexamethasone (DXMS) and subsequently given FTZ capsules. We analyzed the resulting phenotypic changes in these mice using Micro-CT scans and histomorphological studies. Primary osteoblasts, isolated from both Mekk2-/- and WT mice, underwent qRT-PCR to measure key osteogenesis markers, including Runx2, Sp7, Bgalp, Col1a1 and Alp. Cells were then exposed to treatments with either FTZ or Wnt3a and the phosphorylation levels of β-catenin and Mekk2, along with the protein expression of Runx2, were evaluated using Western blotting and immunoprecipitation. Additionally, C3H10T1/2 cells transfected with TOPflash-luciferase and Renilla luciferase reporters were treated with FTZ and Wnt3a to measure β-catenin activity.

RESULTS

In our study, administering FTZ in vivo effectively prevented bone loss typically induced by GCs. However, it's important to note that this protective effect was substantially reduced in mice lacking Mekk2. Additionally, FTZ showed a significant ability to enhance osteogenic differentiation in primary osteoblasts, doing so by altering the expression of Mekk2. Intriguingly, the impact of FTZ on Mekk2 appears to function through a pathway separate from the traditional Wnt signaling route. Furthermore, our findings indicate that FTZ also promotes the deubiquitination of β-catenin, contributing further to its positive effects on bone health.

CONCLUSIONS

This study suggests that FTZ plays a significant role in protecting bone mass in cases of GIOP. The mechanism through which FTZ confers this benefit involves the activation of Mekk2/β-catenin signaling pathways, which represents a promising alternative strategy to counteract the deleterious effects of GIOP by augmenting osteoblastogenesis.

How to manage Cushing's disease after failed primary pituitary surgery

The first-line treatment for Cushing's disease is transsphenoidal adenomectomy, which can be curative in a significant number of patients. The second-line options in cases of failed primary pituitary surgery include repeat surgery, medical therapy, and radiation. The role for medical therapy has expanded in the last decade, and options include pituitary-targeting drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. Bilateral adrenalectomy is a more aggressive approach, which may be necessary in cases of persistent hypercortisolism despite surgery, medical treatment, or radiation or when rapid normalization of cortisol is needed. We review the available treatment options for Cushing's disease, focusing on the second-line treatment options to consider after failed primary pituitary surgery.

Comparison of bone turnover suppression in atypical femoral fractures and osteoporotic hip fractures

We aimed to compare the extent of bone turnover suppression between patients with atypical femoral fractures (AFFs) and osteoporotic hip fractures (typical femur fractures, TFFs) using a one-to-one matching strategy. A single-center retrospective comparison of females aged ≥ 60 years who underwent operative treatment for AFFs and TFFs between January 2010 and March 2021 was conducted. Demographic characteristics and clinical data including fracture site, past medical history, bone mineral density (BMD), bisphosphonate (BP) medication history, and serum bone turnover marker (BTM) levels were examined. Moreover, we performed a logistic regression analysis to determine the risk factors for AFFs and a one-to-one matched-pair analysis to compare various BTMs. Overall, 336 consecutive females were included: 113 with AFFs and 213 with TFFs. The mean age, BMI, and lowest BMD T-score were 78.6 years, 22.8 kg/m2, and -3.3, respectively. Patients with AFF were younger, had lower BMD, higher BMI, higher prevalence of rheumatoid arthritis, a greater proportion with previous steroid or BP use, and a longer history of BP use than patients with TFF. The 48:48 matched-pair analysis revealed higher serum 25(OH) vitamin-D (30.5 vs 18.2 ng/mL, P < 0.001) and calcium levels (8.8 vs 8.3 ng/dL, P = 0.009) and lower serum CTX levels (0.33 vs 0.54 ng/mL, P = 0.010) in the AFF group than in the TFF group, suggesting a more suppressed bone remodeling. No differences in the other BTM levels were found. Despite identical histories and durations of BP use, the AFF group exhibited lower CTX levels, suggesting more suppressed bone remodeling. This observation leads us to infer that more suppressed bone remodeling, indicated by lower CTX levels, could be linked to the occurrence of AFFs.

Fragility Fractures and Cortisol Secretion in Patients With Nonfunctioning Adrenal Incidentalomas

Context

The risk of vertebral fractures (VFx) in patients with nonfunctioning adrenal incidentalomas (NFAI) is unknown.

Objective

This work aimed to assess in NFAI patients the prevalence and incidence of VFx and a hormonal marker to identify patients at risk.

Methods

A retrospective, cross-sectional, and longitudinal study of outpatients was conducted. A total of 306 NFAI patients (cross-sectional arm) and 213 controls were evaluated for VFx prevalence; 85 NFAI patients (longitudinal arm, follow-up 30.3 ± 17.5 months) were evaluated for VFx incidence. Main outcome measures included serum cortisol after 1 mg-dexamethasone test (F-1mgDST), lumbar spinal (LS), and femoral neck (FN) bone mineral density (BMD) and VFx presence, by radiograph of the spine.

Results

Cross-sectional arm: prevalent VFx associated with F-1mgDST with a cutoff of 1.2 µg/dL (33 nmol/L, area under the curve 0.620 ± 0.39; P = .002). Compared with controls and NFAI patients with F-1mgDST less than 1.2 µg/dL (group A), NFAI patients with F-1mgDST greater than or equal to 1.2 µg/dL (group B) showed a higher VFx prevalence (10.8%, 12.6%, and 29.5%, respectively; P < .001 all comparisons), which was associated with F-1mgDST greater than or equal to 1.2 µg/dL (odds ratio 3.02; 95% CI, 1.63-5.58; P < .001) accounting to confounders. Longitudinal arm: the VFx incidence was higher in group B than in group A (19.3% vs 3.6%; P = .05). In group B, all incident VFx occurred in patients without low BMD. The F-1mgDST cutoff for predicting an incident VFx was 1.2 µg/dL, although statistical significance was not reached after adjustment for confounders (P = .061).

Conclusion

In NFAI patients, F-1mgDST levels greater than or equal to 1.2 µg/L (33 nmol/L) are associated with prevalent VFx and may identify patients at risk of incident VFx.

The Value of Mandibular Indices on Cone Beam Computed Tomography in Secondary Causes of Low Bone Mass

Background: As implant treatment cases increase, many cases of failure/side effects also occur. Generally, dental clinics determine the density of the jawbone using cone beam CT (CBCT). Considering the known potential role of this tool for bone assessment in primary osteoporosis, this study evaluated patients with secondary endocrine causes of low bone mass. Methods: The study included 83 patients with endocrine causes of osteoporosis who were evaluated by dual-energy X-ray absorptiometry (DXA), trabecular bone score (TBS), and mental foramen (MF) region CBCT. The following CBCT indices were measured: anterior (A)-thickness of inferior mandibular cortex 10 mm anterior from MF; molar (M)-thickness of inferior mandibular cortex 10 mm posterior from MF; posterior (P)-thickness of inferior mandibular cortex 25 mm posterior from MF; symphysis (S)-thickness of inferior mandibular cortex equidistant from the centers of right and left MF. Results: The highest correlation coefficient in the secondary causes group was between the A index and the lumbar BMD (r = 0.375, p = 0.001) and the P index and the femoral neck BMD (r = 0.38, p = 0.001). Hypercortisolism seems to be the most predictable cause of secondary osteoporosis using the A, M, and P indices. The A, M, and P indices showed predictive values of the bone micro-architecture that was evaluated using TBS score, and were statistically significant. The symphysis index does not significantly predict osteoporosis or impaired bone micro-architecture. Conclusions: These findings support the potential usefulness of A, M, and P CBCT-derived radiomorphometric mandibular indices in secondary osteoporosis, underlining the well-known effects of these pathologies on bone micro-architecture rather than bone quantity.

Preventive machine learning models incorporating health checkup data and hair mineral analysis for low bone mass identification

Machine learning (ML) models have been increasingly employed to predict osteoporosis. However, the incorporation of hair minerals into ML models remains unexplored. This study aimed to develop ML models for predicting low bone mass (LBM) using health checkup data and hair mineral analysis. A total of 1206 postmenopausal women and 820 men aged 50 years or older at a health promotion center were included in this study. LBM was defined as a T-score below - 1 at the lumbar, femur neck, or total hip area. The proportion of individuals with LBM was 59.4% (n = 1205). The features used in the models comprised 50 health checkup items and 22 hair minerals. The ML algorithms employed were Extreme Gradient Boosting (XGB), Random Forest (RF), Gradient Boosting (GB), and Adaptive Boosting (AdaBoost). The subjects were divided into training and test datasets with an 80:20 ratio. The area under the receiver operating characteristic curve (AUROC), accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and an F1 score were evaluated to measure the performances of the models. Through 50 repetitions, the mean (standard deviation) AUROC for LBM was 0.744 (± 0.021) for XGB, the highest among the models, followed by 0.737 (± 0.023) for AdaBoost, and 0.733 (± 0.023) for GB, and 0.732 (± 0.021) for RF. The XGB model had an accuracy of 68.7%, sensitivity of 80.7%, specificity of 51.1%, PPV of 70.9%, NPV of 64.3%, and an F1 score of 0.754. However, these performance metrics did not demonstrate notable differences among the models. The XGB model identified sulfur, sodium, mercury, copper, magnesium, arsenic, and phosphate as crucial hair mineral features. The study findings emphasize the significance of employing ML algorithms for predicting LBM. Integrating health checkup data and hair mineral analysis into these models may provide valuable insights into identifying individuals at risk of LBM.

Global Trends in Research of Programmed Cell Death in Osteoporosis: A Bibliometric and Visualized Analysis (2000-2023)

Osteoporosis (OP) is a systemic metabolic bone disease that is characterized by decreased bone mineral density and microstructural damage to bone tissue. Recent studies have demonstrated significant advances in the research of programmed cell death (PCD) in OP. However, there is no bibliometric analysis in this research field. This study searched the Web of Science Core Collection (WoSCC) database for literature related to OP and PCD from 2000 to 2023. This study used VOSviewers 1.6.20, the "bibliometrix" R package, and CiteSpace (6.2.R3) for bibliometric and visualization analysis. A total of 2905 articles from 80 countries were included, with China and the United States leading the way. The number of publications related to PCD in OP is increasing year by year. The main research institutions are Shanghai Jiao Tong University, Chinese Medical University, Southern Medical University, Zhejiang University, and Soochow University. Bone is the most popular journal in the field of PCD in OP, and the Journal of Bone and Mineral Research is the most co-cited journal. These publications come from 14,801 authors, with Liu Zong-Ping, Yang Lei, Manolagas Stavros C, Zhang Wei, and Zhao Hong-Yan having published the most papers. Ronald S. Weinstein was co-cited most often. Oxidative stress and autophagy are the current research hot spots for PCD in OP. This bibliometric study provides the first comprehensive summary of trends and developments in PCD research in OP. This information identifies the most recent research frontiers and hot directions, which will provide a definitive reference for scholars studying PCD in OP.

A comprehensive review on glucocorticoids induced osteoporosis: A medication caused disease

Glucocorticoids (GCs) are steroid hormones that are extensively used in the treatment of autoimmune diseases, inflammation, and cancer. The major ill effect of administering GCs is that it has a deleterious effect on bone, which leads to GC-induced osteoporosis. GC therapy induces bone loss and is associated with the risk of nonvertebral and vertebral fractures, as it works in combination by increasing bone reabsorption and suppressing bone formation during the initial phase of therapy. It is seen and established that GC in excess or in low dose for 3 months or more can be a risk factor for fracture, and the risk increases with an increase in dose and duration of usage. The most common cause of secondary osteoporosis is the administration of GC inside the body to treat various diseases. The degree of bone loss is directly proportional to the GC dose and the exposure duration. The first step is to evaluate the patients' risk factors for the development of glucocorticoids that induce osteoporosis, which include the dose, duration of use, patient age, sex, previous fractures, and other medical conditions.

Are comorbidities of patients with adrenal incidentaloma tied to sex?

Background

A recent cross-sectional study showed that both comorbidities and mortality in patients with adrenal incidentaloma (AI) are tied to sex. However, few longitudinal studies evaluated the development of arterial hypertension, hyperglycemia, dyslipidemia and bone impairment in patients with AI. The aim of this study is to analyze the impact of sex in the development of these comorbidities during long-term follow-up.

Methods

We retrospectively evaluated 189 patients (120 females, 69 males) with AI, from four referral centers in Italy and Croatia. Clinical characteristics, comorbidities and cortisol after 1-mg dexamethasone suppression test (1-mg DST) were assessed at baseline and at last follow-up visit (LFUV). Median follow-up was 52 (Interquartile Range 25-86) months.

Results

The rates of arterial hypertension and hyperglycemia increased over time both in females (65.8% at baseline versus 77.8% at LFUV, p=0.002; 23.7% at baseline versus 39.6% at LFUV, p<0.001; respectively) and males (58.0% at baseline versus 69.1% at LFUV, p=0.035; 33.8% at baseline versus 54.0% at LFUV, p<0.001; respectively). Patients were stratified in two groups using 1.8 µg/dl as cut-off of cortisol following 1-mg DST: non-functional adrenal tumors (NFAT) and tumors with mild autonomous cortisol secretion (MACS). In the NFAT group (99 patients, females 62.6%), at baseline, we did not observe any difference in clinical characteristics and comorbidities between males and females. At LFUV, males showed a higher frequency of hyperglycemia than females (57.6% versus 33.9%, p=0.03). In the MACS group (89 patients, females 64.0%), at baseline, the prevalence of hypertension, hyperglycemia and dyslipidemia was similar between sexes, despite females were younger (60, IQR 55-69 versus 67.5, IQR 61-73, years; p=0.01). Moreover, females presented higher rates of bone impairment (89.3% versus 54.5%, p=0.02) than males. At LFUV, a similar sex-related pattern was observed.

Conclusion

Patients with AI frequently develop arterial hypertension and hyperglycemia and should be periodically checked for these comorbidities, regardless of sex. In patients with MACS, the lack of difference between sexes in the frequency of cardiometabolic comorbidities despite that females are younger, and the higher frequency of bone impairment in females, suggest a sex-specific effect of cortisol.

Risk of fractures and use of bisphosphonates in adult patients with immune thrombocytopenia-A nationwide population-based study

Corticosteroids remain the first-line treatment of immune thrombocytopenia (ITP), but increase the risk of osteoporosis and fractures. Bisphosphonates are used for the treatment of osteoporosis, but their usage among patients with ITP has not been systemically described. We investigated the risk of fractures and the use of bisphosphonates in adult patients with primary (pITP) and secondary ITP (sITP) compared with matched comparators in a nationwide registry-based cohort study. We identified 4030 patients with pITP (median age 60 years [IQR, 40-74]), 550 with sITP (median age 59 years [IQR, 43-74]) and 182 939 age-sex-matched general population comparators. All individuals were followed for incident fractures. Bisphosphonate use was estimated for calendar-years and in temporal relation to the ITP diagnosis. Adjusted cause-specific hazard ratio (csHR) for any fracture was 1.37 (95% confidence interval [CI] 1.23; 1.54) for pITP and 1.54 (1.17; 2.03) for sITP. The first-year csHR was 1.82 (1.39; 2.40) for pITP and 2.78 (1.58; 4.91) for sITP. Bisphosphonate use over calendar-years and in the early years following ITP diagnosis was higher among patients with ITP diagnosis compared with the general population. In conclusion, the risk of fractures and the use of bisphosphonates are higher in patients with ITP compared with the general population.

Bone-Modifying Agents in Patients With High-Risk Metastatic Castration-Sensitive Prostate Cancer Treated With Abiraterone Acetate

Importance

The association between the use of bone-modifying agents (BMAs) and the outcomes among patients with metastatic castration-sensitive prostate cancer (mCSPC) treated with abiraterone acetate plus prednisone (AAP) remains unclear.

Objective

To investigate the association between BMA use and the outcomes of patients with mCSPC receiving AAP.

Design, Setting, and Participants

In this cohort study, a post hoc analysis of individual participant data from the LATITUDE trial was performed. The LATITUDE trial, a phase 3 randomized clinical trial, aimed to assess the efficacy of AAP and androgen deprivation therapy (ADT) vs dual-placebo and ADT in patients with high-risk mCSPC (data cutoff, August 15, 2018). Eligible patients had newly diagnosed prostate cancer with metastases and at least 2 of 3 high-risk factors (Gleason score ≥8, presence of ≥3 lesions on bone scan, or presence of measurable visceral metastasis). The trial was conducted at 235 sites in 34 countries. Data for the present study were evaluated from July 18 to September 23, 2023.

Exposures

Use of BMAs was defined as the administration of bisphosphonates and denosumab within 90 days before and after randomization.

Main Outcomes and Measures

The primary outcomes were time to skeletal-related events (SREs) and overall survival (OS). An SRE was defined as a clinical or pathological fracture, spinal cord compression, palliative radiation to bone, or surgery involving bone. Differences in these outcomes were examined using the restricted mean survival time from inverse probability of treatment weighting-adjusted Kaplan-Meier curves, estimated until the last event was observed (longest time observed, 63.9 months). Treatment × covariate interactions were analyzed using weighted Cox proportional hazards regression models for the total cohort.

Results

In the total cohort of 1199 patients (956 [79.7%] younger than 75 years), 597 (49.8%) received AAP and ADT, including 474 (79.4%) younger than 75 years and 384 (64.3%) with more than 10 bone metastases (AAP cohort); 602 (50.2%) were treated with dual placebo and ADT, including 482 (80.1%) younger than 75 years and 377 (62.6%) with more than 10 bone metastases (ADT cohort). In the AAP cohort, 132 patients (22.1%) received BMAs, while in the ADT cohort, 131 (21.8%) did. Zoledronic acid was the most frequently administered BMA in both the AAP (93 [70.5%]) and the ADT (88 [67.2%]) cohorts. During the median follow-up of 51.8 (IQR, 47.2-57.0) months in the AAP cohort, BMA use was associated with a longer time to SRE (difference, 7.8 [95% CI, 4.2-11.3] months) but not with OS (difference, 1.6 [95% CI, -2.5 to 5.8] months). In the ADT cohort, BMA use was associated with both time to SRE (difference, 9.3 [95% CI, 5.2-13.3] months) and OS (difference, 5.5 [95% CI, 3.2-9.8] months). No evidence was found that the outcomes of BMA varied by AAP or ADT (hazard ratio for time to SRE, 0.99 [95% CI, 0.48-2.08]; P = .99 for interaction; hazard ratio for OS, 1.31 [95% CI, 0.88-1.96]; P = .18 for interaction).

Conclusions and Relevance

The findings of this cohort study suggest that use of BMAs was associated with a longer time to SRE in patients with high-risk mCSPC treated with ADT, with or without AAP, suggesting that BMA use might provide benefits to this population.

Insights into the antiosteoporotic mechanism of the soy-derived isoflavone genistein: Modulation of the Wnt/beta-catenin signaling

Bone remodeling is a process that involves osteoblasts, osteoclasts, and osteocytes, and different intracellular signaling, such as the canonical Wnt/β-catenin pathway. Dysregulations of this pathway may also occur during secondary osteoporosis, as in the case of glucocorticoid-induced osteoporosis (GIO), which accelerates osteoblast and osteocyte apoptosis by reducing bone formation, osteoblast differentiation and function, accelerates in turn osteoblast, and osteocyte apoptosis. Genistein is a soy-derived nutrient belonging to the class of isoflavones that reduces bone loss in osteopenic menopausal women, inhibiting bone resorption; however, genistein may also favor bone formation. The aim of this study was to investigate whether estrogen receptor stimulation by genistein might promote osteoblast and osteocyte function during glucocorticoid challenge. Primary osteoblasts, collected from C57BL6/J mice, and MLO-A5 osteocyte cell line were used to reproduce an in vitro model of GIO by adding dexamethasone (1 μM) for 24 h. Cells were then treated with genistein for 24 h and quantitative Polymerase Chain Reaction (qPCR) and western blot were performed to study whether genistein activated the Wnt/β-catenin pathway. Dexamethasone challenge reduced bone formation in primary osteoblasts and bone mineralization in osteocytes; moreover, canonical Wnt/β-catenin pathway was reduced following incubation with dexamethasone in both osteoblasts and osteocytes. Genistein reverted these changes and this effect was mediated by both estrogen receptors α and β. These data suggest that genistein could induce bone remodeling through Wnt/β-catenin pathway activation.

Potential Rheumatoid Arthritis-Associated Interstitial Lung Disease Treatment and Computational Approach for Future Drug Development

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by swelling in at least one joint. Owing to an overactive immune response, extra-articular manifestations are observed in certain cases, with interstitial lung disease (ILD) being the most common. Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by chronic inflammation of the interstitial space, which causes fibrosis and the scarring of lung tissue. Controlling inflammation and pulmonary fibrosis in RA-ILD is important because they are associated with high morbidity and mortality. Pirfenidone and nintedanib are specific drugs against idiopathic pulmonary fibrosis and showed efficacy against RA-ILD in several clinical trials. Immunosuppressants and disease-modifying antirheumatic drugs (DMARDs) with anti-fibrotic effects have also been used to treat RA-ILD. Immunosuppressants moderate the overexpression of cytokines and immune cells to reduce pulmonary damage and slow the progression of fibrosis. DMARDs with mild anti-fibrotic effects target specific fibrotic pathways to regulate fibrogenic cellular activity, extracellular matrix homeostasis, and oxidative stress levels. Therefore, specific medications are required to effectively treat RA-ILD. In this review, the commonly used RA-ILD treatments are discussed based on their molecular mechanisms and clinical trial results. In addition, a computational approach is proposed to develop specific drugs for RA-ILD.

Eosinophils preserve bone homeostasis by inhibiting excessive osteoclast formation and activity via eosinophil peroxidase

Eosinophils are involved in tissue homeostasis. Herein, we unveiled eosinophils as important regulators of bone homeostasis. Eosinophils are localized in proximity to bone-resorbing osteoclasts in the bone marrow. The absence of eosinophils in ΔdblGATA mice results in lower bone mass under steady-state conditions and amplified bone loss upon sex hormone deprivation and inflammatory arthritis. Conversely, increased numbers of eosinophils in IL-5 transgenic mice enhance bone mass under steady-state conditions and protect from hormone- and inflammation- mediated bone loss. Eosinophils strongly inhibit the differentiation and demineralization activity of osteoclasts and lead to profound changes in the transcriptional profile of osteoclasts. This osteoclast-suppressive effect of eosinophils is based on the release of eosinophil peroxidase causing impaired reactive oxygen species and mitogen-activated protein kinase induction in osteoclast precursors. In humans, the number and the activity of eosinophils correlates with bone mass in healthy participants and rheumatoid arthritis patients. Taken together, experimental and human data indicate a regulatory function of eosinophils on bone.