Pathogenesis of glucocorticoid-induced osteoporosis and options for treatment

Steroid hormones in pain: Mechanistic underpinnings and therapeutic perspectives

Pain is a complex sensory and emotional experience that severely affects an individual's quality of life and health status. Steroid hormones, as important regulatory substances in the human body, are extensively involved in various physiological and pathological processes. In recent years, remarkable progress has been made in the research of steroid hormones in the field of pain. They play a crucial role in the occurrence, development, and treatment of pain. This review comprehensively elaborates on the roles and therapeutic mechanisms of steroid hormones in pain, explores the performances of glucocorticoids, mineralocorticoids, sex hormones, etc. in different pain models, as well as the molecular mechanisms by which they regulate pain through genomic and non-genomic effects, aiming to provide a theoretical basis for the clinical treatment of pain.

Platelet membrane-cloaked biomimetic nanoparticles for targeted acute lung injury therapy

Acute lung injury (ALI) is a medical condition characterized by significant morbidity and elevated mortality rates; however, to date, there are no clinically approved pharmacological interventions that are both safe and effective for its treatment. In the pathophysiology of ALI, a robust inflammatory response is a critical factor. Dexamethasone (Dex), a potent glucocorticoid, is commonly employed in clinical settings to manage inflammatory conditions. However, the frequent or high-dose administration of corticosteroids can result in significant adverse effects and long-term complications. In this study, we have developed a biomimetic anti-inflammatory nanosystem, designated PM-LPs@Dex, aimed at treating ALI. This system leverages the inherent affinity of platelets for sites of inflammation, alongside the advantageous drug encapsulation properties of liposomes (LPs). By harnessing the suitable physicochemical characteristics of LPs and the distinctive biological functions of platelet membranes (PM), PM-LPs@Dex is capable of stable and sustained drug release in vitro. Experimental results regarding cellular uptake and biodistribution reveal that PM-LPs@Dex is preferentially internalized by inflammatory cells and exhibits enhanced accumulation in inflamed lung tissue compared to LPs@Dex. Pharmacokinetic studies displayed that PM-LPs@Dex showed prolonged circulation time in blood. Additionally, pharmacodynamic assessments demonstrate that PM-LPs@Dex significantly mitigates the severity of ALI, as evidenced by reductions in pulmonary edema, tissue pathology, bronchoalveolar lavage cell counts, protein concentration, and levels of inflammatory cytokines. Notably, PM-LPs@Dex also exhibits favorable biocompatibility. This research is anticipated to contribute novel strategies for the safe and effective targeted management of inflammatory diseases.

Paeonol regulates autophagy through the PI3K-AKT-mTOR signaling pathway to inhibit apoptosis of osteocytes

Osteoporosis is the most common complication of glucocorticoids and predisposes to fractures. Excessive apoptosis of osteocytes is the pathological feature of glucocorticoid-induced osteoporosis. Paeonol, an effective component of Traditional Chinese Medicine Cortex Moutan, known for its anti-inflammatory and analgesic properties, has a long clinical application history. However, the regulatory effect of paeonol on the fate of osteocytes under excessive glucocorticoid remains unclear. The present study aimed to investigate the effect of paeonol against osteocyte death and osteoporosis induced by glucocorticoid and to explore the underlying mechanisms. We found that paeonol not only improved the low proliferation rate of osteocytes induced by dexamethasone but also weakened the dexamethasone-induced apoptosis of osteocytes by stimulating cytoprotective autophagy. Subsequently, proteomic sequencing identified the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) - protein kinase B (AKT) signaling pathway as the potential target of paeonol in attenuating dexamethasone-induced osteocyte injury, and the PI3K activator and inhibitor confirmed this hypothesis. In vivo, paeonol alleviated glucocorticoid-induced osteoporosis, promoted autophagy and inhibited apoptosis of osteocytes by regulating PI3K phosphorylation. In brief, paeonol protects osteocytes from dexamethasone-derived apoptosis by increasing protective autophagy, further inhibiting osteoporosis. Its autophagy-promoting effect was associated with inhibition of PI3K-AKT-mechanistic target of rapamycin (mTOR) of osteocytes.

Anti-IL-6 receptor antibody suppresses onset of paralytic symptoms in AQP4 peptide-immunized mice without lowering bone strength or mineral density

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease characterized by the production of autoantibodies against aquaporin-4 (AQP4). Treatment with prednisolone (PSL) or anti-IL-6 receptor (IL-6R) antibody can reduce the frequency of relapse in patients with AQP4 antibody-positive NMOSD. We previously established a mouse model of paralysis induced by intradermal immunization with AQP4 peptide. In this study, we investigated the effects of PSL and anti-IL-6R antibody treatment on paralysis and on bone fragility in this NMOSD mouse model. Prednisolone and anti-IL-6R antibody treatment each suppressed the clinical scores and incidence of paralytic symptoms in AQP4 peptide-immunized mice. High-PSL treatment induced thinning of cortical bone and reduction of tissue mineral density in the femoral shaft and a decrease in femoral bone strength, although it increased bone volume/tissue volume in the trabecular bone of the distal femur. In contrast, anti-IL-6R treatment showed no significant differences in bone strength or cortical thickness compared to the non-immunized naive group. Bone morphometric analysis showed that high-PSL treatment reduced the bone formation rate in both cortical and trabecular bone, with a predominance of bone resorption, whereas anti-IL-6R treatment demonstrated no notable effect on bone metabolism. These results suggest that anti-IL-6R antibody can prevent the development of paralytic symptoms in AQP4 peptide-immunized mice without reducing bone strength.

Multi-modal microcarriers reprogram mitochondrial metabolism and activate efferocytosis in macrophages for osteoporotic bone repair

Osteoporotic bone repair remains challenging due to the ineffectiveness of traditional bone repair materials in adapting to the complex immune microenvironment of aging bone tissue. Exploiting the key role of macrophages in regulating this immune environment through the rational design of osteoimmunomodulatory biomaterials has emerged as a promising approach. However, current designs inadequately address the complexity of macrophage functions in aging environments, resulting in suboptimal regulatory effects. Hence, we explored multi-modal microcarriers for enhancing macrophage functionality. In this work, we developed a VGX-1027-loaded mesoporous silica nanosphere composite PLLA microcarrier. The dual-carrier system, featuring a micro-nano hybrid design by spatially separating the mesoporous silica nanoparticles and PLLA microspheres, enables sustained intracellular release of VGX-1027, addressing the chronic nature of osteoporotic fractures. Our studies demonstrate this VGX-1027 microcarrier (PMVGX) promotes M2 macrophage polarization by reprogramming mitochondrial metabolism. Simultaneously, it enhances efferocytosis, facilitating the clearance of dead or senescent cells and reducing inflammatory responses, thus reshaping the aging osteoimmunomodulatory. Furthermore, PMVGX induces macrophages to release osteogenic exosomes containing miR-5106 through paracrine signaling, significantly enhancing osteogenic function. In a postmenopausal osteoporosis animal model, PMVGX exhibited remarkable efficacy in repairing osteoporotic bone defects. This proof-of-concept study demonstrates that our multi-modal microcarrier effectively regulates macrophage functions via mitochondrial homeostasis, efferocytosis, and exosome content, offering great potential for osteoporotic bone repair.

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.

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.

Nobiletin ameliorates hormone-induced osteoblast apoptosis by modulating JAK2/STAT3 signaling

Our paper aimed to disclose the effects of nobiletin (NOB) on hormone-induced osteoblast apoptosis and potential action mechanism. MC3T3-E1 cells were randomly separated into normal group, glucocorticoid (GC) group, L-NOB group, M-NOB group, H-NOB group, and Colivelin group (Colivelin: JAK2/STAT3 activator). CCK-8 was applied to ascertain the activity of MC3T3-E1 cells. FITC-Annexin V/PI method was applied to measure cell apoptosis. Alkaline phosphatase (ALP) assay kit was applied to measure ALP activity. Enzyme linked immunosorbent assay (ELISA) was implemented to ascertain the levels of IL-6, IL-1β, TNF-α, and ROS. Western blotting was implemented to distinguish the expressions of JAK2/STAT3 pathway proteins. The viability of MC3T3-E1 cells, ALP activities, and bcl-2 protein level were considerably decreased, while the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were greatly increased in each group after GC treatment. In comparison with GC group, MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level in the L-NOB group, M-NOB group, and H-NOB group were greatly increased. Conversely, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins were markedly reduced. In contrast to H-NOB group, the apoptotic rate, the levels of TNF-α, IL-1β, IL-6, ROS, and the expressions of pJAK2/JAK2, pSTAT3/STAT3, Caspase-3, and bax proteins in Colivelin group were considerably enhanced, while MC3T3-E1 cell viability, ALP activity, and bcl-2 protein level were greatly declined. NOB ameliorates hormone-induced osteoblast apoptosis by reducing JAK2/STAT3 signaling activity.

Association between nutritional and inflammatory status and mortality outcomes in patients with osteoporosis and osteopenia

Osteoporosis, characterized by reduced bone density and microarchitecture deterioration, is a significant global health concern, particularly among aging populations and those with malnutrition. Osteoporotic fractures affect up to 50% of women and 22% of men, making the optimization of assessment metrics crucial. Systemic inflammation, often linked to malnutrition, plays a key role in bone loss. The Advanced Lung Cancer Inflammation Index (ALI), a marker of inflammation and nutrition, shows potential in predicting prognosis but has been insufficiently studied in osteoporosis. This study uses NHANES data to explore ALI's association with mortality in osteoporosis, suggesting its potential as a prognostic tool. Data from the National Health and Nutrition Examination Survey (NHANES) (2007-2023) were analyzed retrospectively. Kaplan-Meier survival curves were used to depict survival data, and the relationship between ALI and mortality was assessed through multivariable Cox regression analysis and restricted cubic spline plots. Subgroup and mediation analyses were also conducted. The study included 4,525 osteoporosis patients with 938 all-cause and 223 cardiovascular deaths. A linear negative correlation between ALI and both all-cause and cardiovascular mortality was observed. Mediation analysis showed that 4.9% and 6.6% of the associations between osteoporosis/osteoporotic fractures and mortality risk were mediated by ALI. Subgroup analyses indicated that ALI predicts mortality across genders and activity levels. This study highlights a linear negative correlation between ALI and both all-cause and cardiovascular mortality in osteoporosis patients.

Prevalence of MRONJ in patients treated with antiresorptive agents for glucocorticoid-induced osteoporosis

PURPOSE

In this study, we aimed to investigate the incidence of medication-related osteonecrosis of the jaw (MRONJ) in patients with glucocorticoid-induced osteoporosis (GIOP) and to examine risk factors for MRONJ development, as well as the preventive effect of tooth extraction before antiresorptive agent (ARA) administration.

METHODS

This retrospective study included patients who received ARA to prevent fragility fractures due to GIOP. The cumulative incidence of MRONJ in patients with GIOP was calculated using the Kaplan-Meier method. Univariate and multivariate Cox regression analyses were used to analyze risk factors for MRONJ occurrence.

RESULTS

The study included 327 individuals. Six patients developed MRONJ; the crude incidence of MRONJ was 1.8%, and the cumulative incidence at 1, 2, 3, 4, and 5 years was 0.32%, 0.97%, 1.35%, 1.85%, and 2.56%, respectively. In this study, 159 teeth were extracted during dental intervention before ARA administration in 58 patients; however, no MRONJ development was observed at the extraction site. Tooth extraction, diabetes mellitus, and duration of ARA administration were not identified as risk factors in this study.

CONCLUSIONS

The incidence of MRONJ in patients with GIOP was higher than the previously reported incidence in patients with age-related osteoporosis but lower than the incidence in patients using high-dose ARA. The results support the effectiveness of prophylactic procedures to remove the infected lesions as much as possible from the jawbone and periodontal tissue before ARA administration.

CLINICAL TRIAL NUMBER

Not applicable.

Osteoimmunology: Crosstalk Between T Cells and Osteoclasts in Osteoporosis

Osteoporosis, a common metabolic condition that affects the bones, increases the risk of fractures, thereby diminishing one's quality of life and, in severe cases, can even result in life-threatening conditions. Osteoporosis is becoming increasingly prevalent worldwide as the population ages. Previous research on osteoporosis has focused on skeletal cellular components such as osteoblasts and osteoclasts. The emerging field of "osteoimmunology" has recently been introduced through new research. The concept highlights the critical impact of bone-immune system interactions on osteoporosis progression. The pathogenesis of osteoporosis is significantly influenced by T cells, particularly cytotoxic and helper T cells, which modulate osteoclast differentiation and activity. A crucial aspect of understanding osteoporosis is how T lymphocytes interact with osteoclasts. However, the precise mechanisms underlying T cell-osteoclast crosstalk remain poorly understood. This review systematically examines T cell and osteoclast involvement in osteoimmunology, with a particular focus on their involvement in osteoporosis. It seeks to elucidate the immune mechanisms driving the progression of osteoporosis and identify key molecules involved in T cell-osteoclast interactions. This aims to discover novel molecular targets and intervention strategies to improve early diagnosis and management of osteoporosis. Furthermore, this article will explore the potential of intervening in T cell-osteoclast interactions using conventional therapies, traditional Chinese medicine, immunomodulatory agents, and nanomaterial-based treatments, providing new perspectives for future osteoporosis management.

Glucocorticoids regulate the expression of Srsf1 through Hdac4/Foxc1 axis to induce apoptosis of osteoblasts

Further study of the mechanism of glucocorticoid (GC)-induced osteoblast (OB) apoptosis is highly important for the prevention and treatment of GC-induced osteoporosis and osteonecrosis. Serine/arginine-rich splicing factor 1 (Srsf1) expression was downregulated in a dose-dependent manner during GC-induced OB apoptosis. Knockdown of Srsf1 significantly promotes GC-induced OB apoptosis, while overexpression of Srsf1 significantly inhibits GC-induced OB apoptosis. Mechanistically, GC induces the up-regulation of histone deacetylase 4 (Hdac4) in OB, and inhibits the expression of transcription activator forkhead box C1 (Foxc1) by reducing the levels of histone H3 lysine 9 acetylation (H3K9ac) and H3K27ac in the promoter region of Foxc1, thereby down-regulating Srsf1. Next, SRSF1 regulates GC-induced OB apoptosis by regulating Bcl-2 modifying factor (Bmf) alternative splicing. From the perspective of alternative splicing, this study demonstrates that Srsf1 and its regulatory mechanism may serve as a new target for the prevention and treatment of GC-induced osteoporosis and osteonecrosis.

The Role of Ferroptosis in Osteoporosis and Advances in Chinese Herbal Interventions

OP, a systemic bone disorder marked by reduced bone mass and heightened fracture risk, poses a significant global health burden, particularly among aging populations. Current treatments, including bisphosphonates and calcium supplementation, are limited by adverse effects and incomplete efficacy. Emerging research highlights ferroptosis-an iron-dependent cell death driven by lipid peroxidation-as a critical contributor to OP pathogenesis, characterized by dysregulated iron metabolism, oxidative stress, and lipid peroxide accumulation, which disrupt bone remodeling by impairing osteoblast function and enhancing osteoclast activity. This review elucidates the mechanistic interplay between ferroptosis and OP subtypes (diabetic osteoporosis (DOP), glucocorticoid-induced (GIOP), and postmenopausal osteoporosis (PMOP)) and evaluates the efficacy of Chinese herbal interventions in mitigating ferroptosis-driven bone loss. Key findings reveal that excess iron exacerbates lipid peroxidation via the Fenton reaction, while glutathione peroxidase 4 (GPX4) inactivation and system Xc- inhibition amplify oxidative damage. In DIOP, hyperglycemia-induced ROS and advanced glycation end products suppress osteogenesis, countered by melatonin and naringenin via nuclear factor -related factor 2 (Nrf2)/GPX4 activation. GIOP involves dexamethasone-mediated GPX4 downregulation, mitigated by exosomes and melatonin through phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling. PMOP driven by estrogen deficiency-induced iron overload is alleviated by aconitine and icariin (ICA) via nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways. Chinese herbs, including active compounds (quercetin, gastrodin, ICA, etc.) and formulations (Bugu Shengsui Capsule, Erxian Decoction (EXD), etc.), regulate iron metabolism, enhance antioxidant defenses (Nrf2/heme oxygenase 1(HO-1)), and inhibit lipid peroxidation, effectively restoring bone homeostasis. These findings underscore ferroptosis as a pivotal mechanism in OP progression and highlight the therapeutic promise of Chinese herbs in bridging traditional medicine with modern mechanistic insights. Future research should prioritize elucidating precise molecular targets, optimizing formulations, and validating clinical efficacy to address current therapeutic gaps.

Cystic fibrosis-related bone disease: an update on screening, diagnosis, and treatment

Cystic fibrosis-related bone disease (CFBD) is a common endocrinopathy in people living with cystic fibrosis (CF) that is complex and multifactorial in origin. People with CF experience high rates of progressive bone density loss and increased fracture risk. Focus on prevention and treatment of CFBD is of increasing importance in a now aging CF population. This review will discuss current practices in CFBD, gaps in knowledge, and potential future studies with the goal of advancing the clinical care of patients with CFBD.

Protosappanin B activates the Wnt pathway to protect against glucocorticoid-induced osteoblast inhibition and enhance bone formation

Osteoporosis remains a major health challenge due to impaired osteoblast function and reduced bone formation, particularly in glucocorticoid-induced osteoporosis (GIOP). The Wnt/β-catenin signaling pathway plays a critical role in osteogenesis, making it a promising target for protective interventions against osteoporosis-related bone loss. In this study, virtual screening of a natural product library identified Protosappanin B (PB) as a potential Wnt pathway activator with high binding affinity for Wnt receptors. We investigated PB's protective effects on osteoblast function under glucocorticoid exposure using MC3T3-E1 cells treated with dexamethasone (DEX) and an in vivo zebrafish model of GIOP. PB significantly promoted osteoblast proliferation, facilitated cell cycle progression, and attenuated DEX-induced apoptosis in a dose-dependent manner. Additionally, PB enhanced osteoblast differentiation and mineralization, counteracting DEX's inhibitory effects on alkaline phosphatase (ALP) activity and calcium deposition. In zebrafish, PB mitigated DEX-induced skeletal defects, improving bone and craniofacial cartilage formation. Western blot analysis confirmed that PB restored β-catenin levels, activating the Wnt/β-catenin pathway. Notably, the osteogenic effects of PB were abolished by XAV939, a Wnt signaling inhibitor, further supporting its Wnt-dependent mechanism of action. These findings indicate that PB provides protective effects against glucocorticoid-induced osteoblast dysfunction and bone loss by modulating Wnt signaling. This study highlight the potential of PB as a natural agent for preventing GIOP-related bone deterioration and warrants further investigation into its clinical applicability.

FKBP5 Induces Senescence in BMSCs and Inhibits Osteogenic Differentiation Through the Canonical WNT/β-Catenin Signalling Pathway in Senile Osteoporosis

Senile osteoporosis and its associated fractures significantly contribute to increased morbidity, mortality, and healthcare costs among older adults. Further research is needed to elucidate the molecular mechanisms underlying senile osteoporosis. This study found that FKBP5 expression in bone marrow mesenchymal stem cells (BMSCs) increases with age and is inversely correlated with patients' bone mineral density and CT values. Functional analyses revealed that FKBP5 plays a crucial regulatory role in BMSC osteogenic differentiation, acting through the canonical WNT/β-catenin signalling pathway. FKBP5 binds to β-catenin, promoting its ubiquitination and degradation. Importantly, administration of SAFit2, a selective FKBP5 inhibitor, enhanced bone mineral density in an animal model of senile osteoporosis. These findings suggest that FKBP5 may represent a novel therapeutic target and provide new insights into the treatment of senile osteoporosis.

Zoledronic acid in metastatic castrate-sensitive prostate cancer: A state-of-the-art review

Prostate cancer is the most common cancer in men in developed countries. Despite its slow growing pattern, metastatic disease to bone occurs and results in a significant number of deaths. Since more than eight decades, the classical androgen deprivation therapy (ADT) leads to clinical response in most patients with metastatic castration-sensitive prostate cancer (mCSPC). Moving backward docetaxel and androgen receptor pathway inhibitors (ARPI) from castrate-resistant setting to castrate sensitive setting improves overall survival (OS) compared to ADT alone. Recently, studies suggested that triplet therapy by adding ARPIs such as abiraterone acetate or darolutamide to ADT + docetaxel is more effective than ADT/docetaxel alone in patients with high-volume mCSPC. Although the scientific progress during the last decade, has led to improvements in outcome for patients with mCSPC, there are still several areas impacting daily practice, for which high-level evidence is lacking, especially for adding monthly zoledronic acid in this setting. We structured this review by conducting a comprehensive analysis of the existing literature. This manuscript reviews both the benefits and potential harms of zoledronic acid in the treatment of mCSPC and provides conclusions on the criteria for its use, and the possible use of alternative bone protecting agents (BPA).

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.

Revolutionary Changes in the Management of Lupus Nephritis: Towards De-Glucocorticoid or No-Glucocorticoid

Glucocorticoids (GCs) possess potent anti-inflammatory and immunosuppressive properties and are used to treat various diseases, including systemic autoimmune rheumatic diseases, rheumatoid arthritis, and systemic lupus erythematosus (SLE). However, GCs are associated with several adverse events and are considered risk factors for infections and cardiovascular disorders; furthermore, their application as therapeutics has changed with recent progress in molecular-targeted therapies. Although GCs have been the mainstay of SLE treatment for more than 50 years, the latest European Alliance of Association for Rheumatology recommendations for the management of SLE in 2023 has significantly relegated the use of GCs and recommended that these be used as "bridging therapy" during periods of SLE disease activity. They also recommended the use of GC pulse therapy followed by relatively low doses of GCs even in patients with high disease-activity lupus nephritis, with a focus on the appropriate use of hydroxychloroquine, immunosuppressive drugs, and biological agents. This combination is essential for improving renal survival, minimizing flares, and reducing the side effects of GC. The GC dose was tapered to < 5 mg/day of prednisolone within half a year, maintained for 3 years, and then discontinued with the concomitant use of combination therapies. In contrast to non-renal SLE, the development of more potent molecular targeted therapies for lupus nephritis is required.

Metformin ameliorates osteoporosis by enhancing bone angiogenesis via the YAP1/TAZ-HIF1α axis

BACKGROUND

Osteoporosis, resulting from an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation, affects millions globally. Recent studies have identified type H vessels (CD31hiEMCNhi) as a specialized subset of bone blood vessels that positively regulate bone formation. This study aims to investigate the effects of metformin on bone mass, strength, and angiogenesis in osteoporotic mice, and to elucidate the underlying molecular mechanisms, particularly focusing on the YAP1/TAZ-HIF1α axis.

METHODS

Osteoporotic mice were administered metformin, and bone mass and strength were measured. In vivo and in vitro angiogenesis assays were performed under hypoxic conditions. Expression levels of YAP1/TAZ and HIF1α were assessed in femoral metaphysis and hypoxia-cultured human microvascular endothelial cells (HMECs). Small interfering RNA was used to interfere with HIF1α or YAP1/TAZ expression in hypoxia-cultured HMECs. Additionally, we employed AAV-mediated overexpression of YAP1/TAZ in vivo to determine whether elevated YAP1/TAZ levels alter metformin's effects on bone mass and angiogenesis.

RESULTS

Metformin significantly enhanced bone mass and strength in osteoporotic mice. It also promoted angiogenesis under hypoxia conditions both in vivo and in vitro. Metformin reduced YAP1/TAZ expression while increasing HIF1α expression in both the femoral metaphysis of osteoporotic mice and hypoxia-cultured HMECs. Interference with HIF1α or YAP1/TAZ confirmed that metformin enhances HIF1α and its target genes primarily by inhibiting YAP1/TAZ. Furthermore, overexpression of YAP1/TAZ partially reversed the bone-protective effect of metformin, leading to reduced HIF1α levels and diminished type H vessel formation.

CONCLUSION

Our findings suggest that metformin holds promise as a therapeutic agent for osteoporosis by enhancing type H vessel formation through the inhibition of the YAP1/TAZ-HIF1α axis.

Rhythms in Remodeling: Posttranslational Regulation of Bone by the Circadian Clock

The circadian clock is a fundamental timekeeping system that regulates rhythmic biological processes in response to environmental light-dark cycles. In mammals, core clock genes (CLOCK, BMAL1, PER, and CRY) orchestrate these rhythms through transcriptional-translational feedback loops, influencing various physiological functions, including bone remodeling. Bone homeostasis relies on the coordinated activities of osteoblasts, osteoclasts, and osteocytes, with increasing evidence highlighting the role of circadian regulation in maintaining skeletal integrity. Disruptions in circadian rhythms are linked to bone disorders such as osteoporosis. Posttranslational modifications (PTMs), including phosphorylation, acetylation, and ubiquitination, serve as crucial regulators of both circadian mechanisms and bone metabolism. However, the specific role of PTMs in integrating circadian timing with bone remodeling remains underexplored. This review examines the intersection of circadian regulation and PTMs in bone biology, elucidating their impact on bone cell function and homeostasis. Understanding these interactions may uncover novel therapeutic targets for skeletal diseases associated with circadian disruptions.

Targeting Wnt signaling pathway with small-molecule therapeutics for treating osteoporosis

Small molecules are emerging as potential candidates for treating osteoporosis by activating canonical Wnt signaling. These candidates work either by inhibiting DKK-1, sclerostin, SFRP-1, NOTUM, and S1P lyase or by preventing β-catenin degradation through inhibition of GSK-3β, or by targeting Dvl-CXXC5 and axin/β-catenin interactions. While many of these anti-osteoporotic small molecules are in preclinical development, the paucity of FDA-approved small molecules, or promising candidates, that have progressed to clinical trials for treating bone disorders through this mechanism poses a challenge. Despite advancements in computer-aided drug design, it is rarely employed for designing Wnt signaling activators to treat osteoporosis, and high-throughput screen (HTS) remains the primary method for discovering initial hits. Acknowledging the promising therapeutic potential of these compounds in addressing bone diseases, this review underscores the need for further mechanistic elucidation to enhance our understanding of their applications. Additionally, caution must be exercised in the design of small molecule-based Wnt activators due to their association with oncological risks.

Kurarinone regulates Th17/Treg balance and ameliorates autoimmune uveitis via Rac1 inhibition

INTRODUCTION

Autoimmune uveitis (AU) is a severe intraocular autoimmune disorder with a chronic disease course and a high rate of blindness. Kurarinone (KU), a major component of the traditional Chinese medicine Sophorae Flavescentis Radix, possesses a wide spectrum of activities and has been used to treat several inflammation-related diseases.

OBJECTIVE

We aimed to investigate the effects of KU on AU and its modulatory mechanisms.

METHODS

We used an experimental autoimmune uveitis (EAU) animal model and characterized the comprehensive immune landscape of KU-treated EAU mice using single-cell RNA sequencing (scRNA-seq). The retina and lymph nodes were analyzed. The siRNAs and selective inhibitors were used to study the signaling pathway. The effect of KU on peripheral blood mononuclear cells (PBMCs) from uveitis patients was also examined.

RESULTS

We found that KU relieved chorioretinal lesions and immune cell infiltration in EAU model mice. Subsequent single-cell analysis revealed that KU downregulated the EAU-upregulated expression of inflammatory and autoimmune-related genes and suppressed pathways associated with immune cell differentiation, activation, and migration in a cell-specific manner. KU was implicated in restoring T helper 17 (Th17)/regulatory T (Treg) cell balance by alleviating inflammatory injury and elevating the expression of modulatory mediators in Tregs, while simultaneously ameliorating excessive inflammation by Th17 cells. Furthermore, Rac1 and the Id2/Pim1 axis potentiated the pathogenicity of Th17 cells during EAU, which was inhibited by KU treatment, contributing to the amelioration of EAU-induced inflammation and treatment of AU. In addition, KU suppressed inflammatory cytokine production in activated human PBMCs by inhibiting Rac1. Integration of the glucocorticoid-treated transcriptome suggests that KU has immunomodulatory effects on lymphocytes.

CONCLUSION

Our study constructed a high-resolution atlas of the immunoregulatory effects of KU treatment on EAU and identified its potential therapeutic mechanisms, which hold great promise in treating autoimmune disorders.

["Paradoxical fractures": pathological fractures under anti-osteoporotic and antirheumatic treatment]

Pathological fractures under anti-osteoporotic and antirheumatic treatment are very rare events. Nevertheless, atypical femoral fractures occur during antiresorptive treatment with bisphosphonates or denosumab, the latter especially in patients previously treated with bisphosphonates. Treatment with teriparatide can be helpful. While glucocorticoids have a well-known influence on the development of osteoporosis and thus also fractures, the probably unproblematic use in the low-dose range has so far found little acceptance. Methotrexate-induced osteopathy is also a rare phenomenon but is now well accepted and known. There are several approved medications for the treatment of glucocorticoid-induced osteoporosis and for methotrexate-induced osteopathy, discontinuation of methotrexate is particularly essential.

CUL1 exacerbates glucocorticoid-induced osteoporosis by enhancing ASAP1 ubiquitination

BACKGROUND

Glucocorticoid-induced osteoporosis is a leading secondary cause of osteoporosis. Cullin-1 (CUL1) levels are abnormally elevated in patients with osteoporosis, but the underlying mechanism remains unclear. The purpose of this study was to elucidate the mechanism of action of CUL1 in a glucocorticoid (dexamethasone, Dex)-induced osteoporosis model.

METHODS

C57BL/6J mice were intraperitoneally injected with Dex to establish an osteoporosis model. Mouse femur bone injury and bone formation were detected using hematoxylin-eosin or Masson staining. Apoptosis and cell cycle distribution were determined by flow cytometry. Alkaline phosphatase (ALP) activity and calcified nodules were monitored using ALP and Alizarin Red S staining. The molecular mechanism was validated by co-immunoprecipitation (Co-IP) and ubiquitination assays.

RESULTS

CUL1 expression was enhanced in the Dex-induced osteoporosis mouse model. CUL1 silencing moderated the Dex-induced cell proliferation and osteogenesis inhibition. Moreover, CUL1 promoted the ubiquitination and degradation of ASAP1 via the SKP1-CUL1-F-box (SCF)-FBXW7 complex. CUL1 induced apoptosis and repressed osteogenesis by ASAP1. CUL1 silencing alleviated the Dex-induced osteoporosis in mice.

CONCLUSION

CUL1 suppressed osteoblast proliferation and osteogenesis by promoting ASAP1 ubiquitination via the SCF-FBXW7 complex in glucocorticoid-induced osteoporosis.

Glycyrol alleviates osteoporosis through dual modulation on osteoclastogenesis and osteogenesis by targeting Syk signaling pathway

BACKGROUND

Osteoporosis, characterized by an imbalance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation, has become a serious public health challenge worldwide. Glycyrol (GC) is a representative natural coumestan isolated from licorice that shows multiple pharmacological activities, but its anti-osteoporotic effect and underlying mechanisms remain unclear.

RESULTS

GC significantly suppressed lipopolysaccharide-induced mouse bone loss and dexamethasone-induced zebrafish bone formation deficiency. Meanwhile, GC exhibited dual effects of inhibiting osteoclast formation and bone resorption, and stimulating osteoblast differentiation and mineralization. By combining kinomic screening assay, bioinformatics analysis and cellular target engagement validation, spleen tyrosine kinase (Syk) was identified as a key kinase target of GC. Subsequently, Syk was determined to play important roles in promoting osteoclast formation and impeding osteoblast differentiation. Interestingly, GC directly bound to the active cavity of Syk through hydrogen bonds and significantly inhibited its activity. Moreover, GC remarkably inhibited RANKL-induced activation of Syk/PLCγ2/Ca2+/NFATc1 and MAPK pathways in macrophages undergoing differentiation into osteoclasts.

CONCLUSION

These results demonstrated that GC exerted a dual regulation on osteoclastogenesis and osteogenesis and consequently alleviated osteoporosis through targeting Syk and its downstream signaling pathways. In addition, the current study emphasizes the key roles of Syk in bone resorption and formation, suggesting the application potential of Syk inhibitors for the management of bone diseases. Meanwhile, this study provides evidence supporting the development of GC or its derivatives as effective anti-resorptive and bone anabolic agents for the prevention or treatment of osteoporosis and other bone diseases.

Reducing PDK4 level constitutes a pivotal mechanism for glucocorticoids to impede osteoblastic differentiation through the enhancement of ferroptosis in mesenchymal stem cells

BACKGROUND

This study mainly explores the possible role and mechanism of pyruvate dehydrogenase kinase 4 (PDK4) in the onset and development of Glucocorticoid-induced osteoporosis (GIOP), and seeks potential targets for the treatment of GIOP.

METHODS

Mesenchymal stem cells (MSCs) were treated with osteogenic induction medium. An in vitro osteogenic damage model was established by exposing MSCs to a high concentration (10- 6 M) of dexamethasone (DEX). Osteogenic markers were measured with real-time quantitative polymerase chain reaction, western blot, alkaline phosphatase staining, and Alizarin Red S staining. Ferroptosis markers were assessed through reactive oxygen species (ROS) fluorescent probe, transmission electron microscopy, and measurement of malondialdehyde (MDA). The potential mechanism was investigated using RT-qPCR, western blot, lysosomal probes, molecular docking, and other analytical approaches. The role of PDK4 was validated by using a GIOP rat model, micro-computed tomography and Masson's trichrome staining.

RESULTS

High concentrations (10- 6 M) of DEX inhibited osteogenic differentiation in C3H10T1/2 cells, and PDK4 exhibited the opposite effect. PDK4 partially reversed the osteogenic inhibitory effect of DEX both in vivo and in vitro. DEX caused mitochondrial shrinkage and disappearance of cristae in C3H10T1/2 cells, as well as an increase in total iron, ROS, MDA contents, and the level of ferroptosis key factors. These changes were partially weakened by PDK4. The ferroptosis inhibitor ferrostatin-1 partially blocked the inhibitory effect of DEX, while ferroptosis inducer RSL3 inhibited osteogenic differentiation and weakened the reversal effect of PDK4. DEX reduced the protein level of PDK4, which was partially weakened by Bafilomycin A1. The molecular docking results showed that DEX can directly bind with PDK4.

CONCLUSION

PDK4 can enhance the osteogenic differentiation ability of MSCs and bone mass of GIOP rats. DEX may promote the degradation of PDK4 via lysosome pathway, through which to weaken the osteogenic ability of MSCs by increasing ferroptosis. PDK4 may become a potential target for improving GIOP.

Modulatory effects of Lycium barbarum polysaccharide on bone cell dynamics in osteoporosis

Background

Osteoporosis (OP) is a systemic bone disorder marked by reduced bone mass and disrupted microstructure, leading to higher fracture risk. Epidemiological data from China show a 20.7% prevalence in women and 14.4% in men over 50, underscoring a pressing health issue given the aging population. More drugs to inhibit OP progression should be explored, and their biological mechanisms confirmed in preclinical studies.

Methods

In this study, we utilized Lycium barbarum polysaccharide (LBP), an extract from the traditional Chinese medicine Goji Berry. LBP, known for its range of pharmacological activities, was assessed for its potential therapeutic effects on OP. We specifically investigated its influence on the proliferation, apoptosis, migration, and functional differentiation of osteoblasts and osteoclasts.

Results

LBP significantly promotes osteoblast proliferation, migration, and osteogenic differentiation. Conversely, it inhibits the intrinsic apoptotic response in osteoblasts. For osteoclasts, LBP suppressed their proliferation, migration, and osteoclastic differentiation while enhancing their natural apoptosis. These results were confirmed by classical protein pathway detection experiments.

Conclusion

LBP showcases potential therapeutic properties against OP, particularly in modulating osteoblast/osteoclast activities. While its exact mechanisms through vital signaling pathways remain to be fully elucidated, LBP's prominent effects suggest that it is a promising agent for OP intervention, warranting further in-depth studies.

Extended-release Hydrocortisone Formulations-Is There a Clinically Meaningful Benefit?

Despite best practice replacement therapy with corticosteroids, patients with adrenal insufficiency report diminished quality of life and face increased mortality and morbidity. Conventional formulations of hydrocortisone have short half-lives (about 90 minutes) requiring multiple dosing during the day. Since 2011, extended-release hydrocortisone (ER-HC) formulations have been available enabling once-, sometimes twice-daily dosing. Most studies comparing ER-HC formulations with conventional hydrocortisone therapy report reduction in body weight, blood pressure and glucose levels, and improved quality of life. However, it is still unclear if the reported beneficiary effects are due to differences in cortisol exposure or alterations in pharmacokinetics. Here, we review studies comparing conventional and ER-HC treatment in adrenal insufficiency and discuss whether these novel formulations are safe and offer clinically significant benefits.

Exploring the osteogenic effects of simiao wan through activation of the PI3K/AKT pathway in osteoblasts

ETHNOPHARMACOLOGICAL RELEVANCE

Osteoporosis (OP) is a degenerative bone disease commonly associated with reduced bone density and increased fracture risk.

AIM OF THE STUDY

This study aimed to validate the therapeutic effects of Simiao wan (SMW) on OP and explore the underlying mechanism, particularly focusing on the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway.

MATERIALS AND METHODS

The chemical components of SMW were identified using UPLC-Q-TOF-MS/MS. The obtained compounds were then input into the TCMSP, TargetNet, and SwissTargetPrediction databases to predict potential targets. OP-related targets were collected from the GeneCards and DisGeNET databases, and intersecting targets were identified through a Venn diagram. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on the intersecting targets using the Database for Annotation, Visualization and Integrated Discovery (DAVID). SMW extract was subsequently used to treat osteoblasts in vitro, and its toxicity on osteoblasts was assessed using Cell Counting Kit-8 (CCK-8) and lactate dehydrogenase (LDH) release assays. Osteoblast differentiation and activity were further evaluated using alizarin red staining, alkaline phosphatase staining, and Western blot analyses to validate the activation of network pharmacological signaling pathways.

RESULTS

A total of 121 potential targets were identified for SMW in the treatment of OP, with AKT1 as the primary target. The PI3K/AKT pathway emerged as a key signaling pathway potentially involved in SMW's therapeutic effects o OP. Toxicity assessments showed no significant toxicity of SMW on osteoblasts. Additionally, SMW promoted osteoblast proliferation, alkaline phosphatase activity, calcium nodule deposition, and the expression of osteogenic markers (osteocalcin (OCN), runt-related transcription factor 2 (RunX2), and collagen I), and activated the PI3K/AKT signaling pathway. The PI3K/AKT pathway inhibitor LY294002 partially reversed the SMW-induced mineral deposition and expression of OCN, RunX2, and collagen I.

CONCLUSION

SMW demonstrated effective multi-target and multi-pathway therapeutic potential in the treatment of OP, with a significant impact on the PI3K/AKT signaling pathway.

The rational use of glucocorticoids may reduce the risk of readmission in menopausal women with knee osteoarthritis: results from a five-year longitudinal study

OBJECTIVE

To investigate the effect of glucocorticoids (GCs) on the risk of readmission in menopausal women with knee osteoarthritis (OA).

INFORMATION AND METHODS

The study cohort comprised 80 menopausal women with knee OA treated at a tertiary hospital affiliated with Shanxi Medical University and who underwent follow-up between September 2018 and September 2023. Then the collected longitudinal monitoring data were used to construct a semi-variable coefficient shared Gamma frailty model (VCSGF). Based on the results of this model, we explored the impact of GCs on menopausal women with knee OA and made risk predictions.

RESULTS

The mean patient age at study entry was 64.7 ± 9.3 (range 50-82 years). And during the research, patients were admitted to the hospital a mean of 2.4 ± 1.8 times (range 1-11 times). Compared to patients who have not used the drug, the risk of early readmission in patients who have used GCs was reduced by 96% (HR = 0.04, 95%CI: 0.006 ~ 0.284, [Formula: see text]). This protective effect diminished over time ([Formula: see text]). In addition, the risk of hospital admission with recurrent symptoms was roughly 3.35-fold higher in patients who drink alcohol than in patients who do not (95%CI: 1.661~6.794, [Formula: see text]).

CONCLUSION

GC use reduced the risk of readmission in menopausal women with knee OA, although this effect diminished over time. Therefore, in patients without further contraindications, GCs may be used in moderation to reduce the readmission risk. In clinical practice, additional research is needed to investigate the timing and appropriate use of GC in the treatment of menopausal women with knee OA, and to develop a more rational program for GC use.

Osteonecrosis: A disabling disease not to be ignored in asthma and atopic conditions

Osteonecrosis, also referred to as avascular necrosis, is a disease characterized by necrosis or death of a bone secondary to impairment in blood supply. The condition affects the epiphyseal ends of the bones such as the femur and the humerus, but it can also involve the metacarpal and metatarsal bones, the patella, the knee, the vertebrae, and the jaw. A plethora of inflammatory, autoimmune, hematological, thrombotic, and vascular diseases can lead to osteonecrosis. Corticosteroids are intimately linked to the development of osteonecrosis. The frequent use of systemic corticosteroids in patients with asthma, eczema, nasal polyposis, sinusitis, urticaria and angioedema, or anaphylaxis makes this disease of great relevance to the practicing allergist and pulmonologist. Untreated, bone necrosis leads to frustrated bone remodeling and angiogenesis, leading to subchondral fractures and collapse of the articular heads of the bones, and culminating in debilitating osteoarthritis, often requiring arthroplasty. Recent studies have shed light on the molecular mechanisms underlying osteonecrosis and on the role of glucocorticoids. The gold standard test in patients suspected of having the disease is magnetic resonance imaging scanning, with plain radiographs having a lower sensitivity and specificity. Early diagnosis and intervention are essential. The allergist should avoid the frequent use of glucocorticoids and consider early introduction of steroid-sparing alternatives for asthma or sinusitis. Smoking and alcohol ingestion need to be addressed, and the management of glucocorticoid-induced osteoporosis may be helpful. It is essential for allergists to familiarize themselves with the disease and its diagnosis and to consider early referral to an orthopedic surgeon for surgical intervention.

Adverse Impacts of Corticosteroid Treatment on Osteoporosis/Osteopenia in Adult Asthmatics: A Retrospective ICARUS Cohort Study

BACKGROUND

Inhaled corticosteroid (ICS) and oral corticosteroid (OCS) are often used in asthma management.

OBJECTIVE

To evaluate the long-term effect of ICS/OCS on osteoporosis, osteopenia, fractures, and bone metabolism in adult patients with asthma in real-world clinical practice.

METHODS

This is a retrospective study investigating deidentified electronic health records from Ajou University Medical Center (Korea). Adult patients with asthma receiving maintenance ICS with/without OCS for at least 1 year were enrolled. They were classified into the high/low-dose of ICS or OCS group. Primary outcomes (incidences of osteoporosis, osteopenia, and fractures) and secondary outcomes (drug prescription and laboratory values related to bone metabolism including albumin and alkaline phosphatase) were compared after 5 years of follow-up.

RESULTS

After propensity score matching, both high- and low-dose OCS groups included 468 patients, and high/low-dose ICS groups each comprised 1252 patients. The risk of osteoporosis/major fracture was higher (hazard ratio [95% CI], 2.00 [1.15-3.57]/3.03 [1.04-11.11]) in the high-dose OCS group (especially in females aged ≥50 years) than in the low-dose group, although the ICS groups showed no significant differences. The high-dose ICS group showed a higher risk of osteopenia (1.92 [1.05-3.70]) than the low-dose ICS group. The linear mixed model of laboratory values showed significantly decreased serum albumin and increased alkaline phosphatase in the high-dose OCS group than in the low-dose OCS group.

CONCLUSIONS

The results of this study suggest that long-term use of OCS can increase the risk of osteoporosis and osteoporosis-related fractures, whereas long-term use of ICS may increase the risk of osteopenia in adult patients with asthma.

Osteoking inhibits apoptosis of BMSCs in osteoporotic rats via PI3K/AKT signaling pathway

In China, Osteoking is a commonly used treatment and preventive measure for osteoporosis. The pathophysiology of osteoporosis is closely associated with apoptosis; however, it remains unclear whether the role of Osteoking in promoting bone formation is linked to apoptosis.

AIM OF STUDY

This study aims to investigate whether Osteoking inhibits apoptosis of BMSCs in osteoporotic rats via the PI3K/AKT signaling pathway and to conduct a detailed exploration of this mechanism. The goal is to provide a theoretical basis for the clinical application of Osteoking in osteoporosis treatment.

METHODS

A rat model of osteoporosis was established through bilateral ovariectomy (OVX), followed by treatment with Osteoking. After ten weeks of therapy, BMD was evaluated. The biomechanics of the left tibia were measured, the left femur was sequenced, and the right tibia was stained using histomorphometric and Masson's staining methods. Peripheral serum was collected to measure bone-related markers, including E2, PINP, and CTX. RNA-Seq results were verified using the remaining bone samples. Comparative analysis demonstrated the efficacy of Osteoking in treating osteoporosis and provided preliminary insights into the underlying mechanisms. Primary BMSCs were cultured using bone marrow apposition. CCK8 assays were conducted to screen the intervention conditions of Osteoking and LY294002. Various concentrations of Osteoking-containing serum and LY294002 were tested separately to determine the optimal intervention concentration for drug delivery. The impact of Osteoking on lipid formation was also evaluated. Following treatment of BMSCs from OVX rats with Sham serum, OVX serum, OVX + LY294002 serum, and Osteoking + LY294002 serum, the expression of PI3K/AKT/mTOR, osteogenesis-related regulatory factors, and apoptosis-related regulatory factors was assessed. Flow cytometry was employed to evaluate apoptosis in BMSCs.

RESULTS

Osteoking significantly improved whole-body BMD and bone biomechanical indices in OVX rats. It also significantly elevated the serum levels of E2 and PINP while reducing the level of CTX, which significantly improved bone microstructure and promoted new bone formation. RNA-seq analysis indicated that the therapeutic mechanism involved the PI3K/AKT signaling pathway. Osteoking increased the expression of RUNX2 and decreased the expression of PPAR-γ, a marker of lipogenesis, in OVX rats. Extraction of BMSCs for subsequent studies revealed a significant reduction in proliferation and osteogenic differentiation, along with an increase in lipogenic differentiation, in the OVX group. Osteoking treatment inhibited the expression of PPAR-γ and increased the expression of RUNX2 in BMSCs. Additionally, Osteoking reversed the LY294002-mediated inhibition of PI3K/AKT/mTOR signaling pathway activation, increased the expression of the apoptosis-protecting protein Bcl2, and decreased the expression of apoptosis-associated proteins Caspase3 and Bax.

CONCLUSION

Osteoking markedly improved bone microstructure, biomechanics, and bone density in OVX rats. Osteoking-containing serum reversed the imbalance in lineage differentiation in OVX rats, characterized by reduced osteogenic differentiation and increased lipid differentiation of BMSCs. Furthermore, Osteoking-containing serum significantly increased BMSC proliferation and prevented apoptosis in OVX rats through the PI3K/AKT signaling pathway.

Impact of glucocorticoids on the therapeutic efficacy of denosumab against osteoporosis in patients with rheumatoid arthritis

Background

Rheumatoid arthritis (RA) and prolonged high-dose glucocorticoid (GC) treatment are established risk factors for osteoporosis.

Objectives

In this study, we aimed to evaluate the therapeutic efficacy of denosumab according to the GC dose considered to increase the risk of glucocorticoid-induced osteoporosis (GIOP) in patients with RA.

Design

A retrospective analysis of collected data on RA patients with osteoporosis starting denosumab.

Methods

We included 418 patients with RA who were started on denosumab therapy and categorized them into those with and without GC intake ⩾2.5 mg/day for >3 months. The T-score and areal bone mineral density (aBMD) at the lumbar spine, total hip, and femur neck, as well as serum bone turnover markers, were measured at baseline and 12 months. We performed between-group and within-group comparisons of the BMD values at baseline and at 12 months.

Results

Denosumab significantly increased the T-scores and aBMD at the lumbar spine, total hip, and femur neck after 12 months, regardless of GC intake. However, apart from the T-score at the lumbar spine, the other parameters did not show significant between-group differences. Similarly, in patients with anti-cyclic citrullinated peptide (CCP) antibody positivity or those treated with biologic or targeted synthetic disease-modifying antirheumatic drugs (DMARDs), although there were significant increases in the T-score and areal BMD at all sites in both groups, there were no significant between-group differences.

Conclusion

Our findings suggest that the GC dose considered to increase the risk of GIOP did not significantly attenuate the therapeutic efficacy of denosumab in RA patients, including those positive for anti-CCP antibodies and users of biologic or targeted synthetic DMARDs.

Clinical Manifestations and Challenges in Adolescent and Adult Females With Classic Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency

Classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH) is a rare genetic condition that results in cortisol deficiency and excess production of adrenal androgens. While the introduction of newborn screening for CAH has reduced morbidity and mortality, management of CAH remains challenging. Lifelong treatment with glucocorticoids is required to replace the endogenous cortisol deficiency and reduce excess adrenal androgens. Undertreatment or overtreatment with glucocorticoids can lead to multiple disease- and treatment-related comorbidities, including impaired growth and compromised final height, menstrual irregularities and reduced fertility in females, and long-term cardiometabolic complications. In addition to avoiding adrenal crisis and sudden death, treatment goals in adolescent females with CAH are to obtain normal growth and bone maturation and normal timing of puberty. Management of adolescents is particularly challenging due to changes in growth and sex hormone levels that can lead to inadequate suppression of adrenal androgens and increasing independence that can affect treatment adherence. During the transition to adult care, treatment goals focus on preventing symptoms of hyperandrogenism, preserving menstrual regularity and fertility, and providing education and support for issues related to sexuality, atypical genitalia, and/or complications from previous surgical treatment. In addition, patients must be monitored continuously to prevent long-term complications such as decreased bone mineral density, obesity, diabetes, and hypertension. In this review, we discuss the challenges faced by adolescent and adult females with CAH and provide guidance to health-care professionals to help patients to navigate these challenges.

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.

Mesenchymal stromal cell-derived extracellular vesicles as nanotherapeutics for concanavalin a-induced hepatitis: modulating the gut‒liver axis

BACKGROUND

As cell-free nanotherapeutics, extracellular vesicles derived from mesenchymal stem cells (MSC-EVs) have shown potential therapeutic action against liver diseases. However, their effects on autoimmune hepatitis (AIH) are not yet well understood.

METHODS AND RESULTS

In this study, we utilized a well-established concanavalin A (Con A)-induced fulminant hepatitis mouse model to investigate the effects of MSC-EVs on AIH. We found that MSC-EVs provide significant protection against Con A-induced hepatitis in C57BL/6 male mice, with their effectiveness being critically dependent on the gut microbiota. MSC-EVs modulate the composition of the gut microbiota, particularly by increasing the abundance of norank_f__Muribaculaceae, and impact liver metabolic profiles, leading to significant amelioration of liver injury. The identification of Acetyl-DL-Valine as a protective metabolite underscores the therapeutic potential of targeting gut‒liver axis interactions in liver diseases.

CONCLUSION

Overall, our data demonstrate that MSC-EVs exhibit nanotherapeutic potential in Con A-induced hepatitis and provide new insights into the treatment of autoimmune hepatitis.

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.

Rapid reduction in fracture risk after the discontinuation of long-term oral glucocorticoid therapy: a retrospective cohort study using a nationwide health insurance claims database in Japan

Increased fracture risk due to oral glucocorticoids (GCs) rapidly decreases with GC discontinuation. However, evidence for this is limited. We found that fracture risk decreased rapidly in the first year after GC discontinuation, while hip fracture risk remained higher than reference levels for about two years after GC discontinuation.

PURPOSE

We investigated changes in fracture risk following discontinuation of long-term oral glucocorticoids (GCs) using Japan's nationwide health insurance claims database (NDBJ).

METHODS

We identified patients aged ≥ 50 years who initiated GC therapy in 2012-2019. Those receiving ≥ 5 mg (prednisolone or equivalent, PSL)/day for ≥ 72 days in the initial 90 days of GC therapy were classified as the GC-exposure group, and those receiving < 5 mg PSL/day for < 30 days were classified as the reference group. Patients discontinuing GC after 90 days of GC therapy were classified as the GC-discontinuation group; all others were classified as the GC-continuation group. We tracked the incidence rates of hip and clinical vertebral fractures for up to 990 days, and assessed fracture risk after GC discontinuation by hazard ratios (HR) adjusted by inverse probability weighting using propensity scores for GC discontinuation.

RESULTS

There was a total of 52,179 GC-discontinuation, 91,969 GC-continuation, and 43,138 reference group women, and 57,560, 93,736, and 33,696 men in the corresponding groups, respectively. According to adjusted HRs, incidence rates of fractures were significantly lower in the GC-discontinuation group than in the GC-continuation group in the initial 90 days after GC discontinuation and remained significant for 360 days, except for hip fracture in men. HRs for hip fractures remained significantly higher in the GC-discontinuation group compared to the reference group for 720 days post-discontinuation.

CONCLUSION

Fracture risk declines rapidly in the first year after GC discontinuation, but vigilance is necessary as the increased risk persists for two years post-discontinuation.

Glucocorticoid therapy in classic congenital adrenal hyperplasia: traditional and new treatment paradigms

INTRODUCTION

Classic congenital adrenal hyperplasia due to 21-hydroxylase deficiency (CAH) is a rare genetic condition characterized by cortisol deficiency and excess adrenal androgens. CAH treatment is a lifelong balancing act between the need to reduce excess androgens, typically with supraphysiologic glucocorticoid (GC) doses, and concerns about potentially serious GC-related adverse events. Tradeoffs between the consequences of excess androgens versus GCs must be constantly reassessed throughout each patient's lifetime, based on current clinical needs and treatment goals. Adding to this burden are limited treatment options and the need for new CAH medications.

AREAS COVERED

This narrative review describes the current challenges of CAH treatment, the potential of new non-GC therapies to reduce excess androgens and thereby allow for lower GC doses, and the potential implications of decreasing GC doses to a more physiologic range (i.e. sufficient to replace missing cortisol, but without the need to reduce androgens).

EXPERT OPINION

Even with non-GC therapies, patients' needs will continue to shift throughout their lifetimes. Treatment will therefore always require joint decision-making between physicians and patients. However, over the lifetimes of patients with CAH, any reduction in GC daily dose may have a large cumulative impact in decreasing the GC-related burden of this disease.

Integrative analysis of crosstalk genes and diagnostic biomarkers in lupus-associated osteoporosis

Systemic lupus erythematosus (SLE) patients are at greater risk of developing osteoporosis (OP) than the general population. This study aimed to identify crosstalk genes between SLE and OP and to validate their diagnostic accuracy as biomarkers. Data analysis based on Gene Expression Omnibus (GEO) datasets was conducted. We utilized Weighted Gene Co-Expression Network Analysis (WGCNA) and differential expression analysis to identify crosstalk genes (CGs). Machine learning algorithms and consensus clustering were applied to screen shared diagnostic biomarkers and construct two predictive models featuring key genes. We also investigated potential subgroups, immune infiltration across different subtypes, and validated hub mRNAs using quantitative real-time PCR (qPCR). Molecular docking was performed to simulate the interaction of a small molecule compound with its target. We identified 19 CGs and developed two predictive models: the IL1R2-GADD45B and CHI3L1-IL1R2-SPTLC2 diagnostic score thresholds. The CHI3L1-IL1R2-SPTLC2 model showed improved predictive accuracy for lupus-associated osteoporosis. The C2 subtype was found to potentially regulate bone metabolism in SLE patients. Immune infiltration analysis indicated a strong association between CGs and multiple immunocytes, with IL1R2 being a common element in both models. Molecular docking suggests that Anakinra's therapeutic effect may involve IL1R2. Our study introduces novel diagnostic biomarkers and predictive models for lupus-associated osteoporosis, with a particular focus on IL1R2 as an innovative biomarker and therapeutic target. These are anticipated to aid early screening and risk assessment in SLE patients, pending large-scale clinical validation.

Osteoporosis in Adrenal Insufficiency: Could Metformin be Protective?

Adrenal insufficiency (AI) is a serious disorder characterized by the adrenal glucocorticoid deficiency. Regardless of the etiology, AI patients need long-term replacement therapy for glucocorticoids and, in some cases, for mineralocorticoids. The replacement therapy cannot completely mirror the physiological secretion patterns, and therefore, glucocorticoid excess is a common sequela in AI patients. Moreover, due to the absence of the reliable clinical markers to monitor the adequacy of the replacement therapy, clinicians often over-treat the AI patients to avoid adrenal crisis. Long-term glucocorticoid use is associated with the loss of bone density and osteoporosis, increasing the risk of fractures. Moreover, glucocorticoid-induced hyperglycemia and type 2 diabetes mellitus further aggravates the bone disorders. In the recent years, ameliorating effects of metformin on glucocorticoid-induced bone disorders, as well as hyperglycemia, have been reported by a multitude of studies; and here, we reviewed and discussed the most recent findings regarding the positive effects of metformin on alleviating the bone disorders, and their implications in the AI patients.

Osteoporosis: Causes, Mechanisms, Treatment and Prevention: Role of Dietary Compounds

Osteoporosis is a chronic disease that is characterized by a loss of bone density, which mainly affects the microstructure of the bones due to a decrease in bone mass, thereby making them more fragile and susceptible to fractures. Osteoporosis is currently considered one of the pandemics of the 21st century, affecting around 200 million people. Its most serious consequence is an increased risk of bone fractures, thus making osteoporosis a major cause of disability and even premature death in the elderly. In this review, we discuss its causes, the biochemical mechanisms of bone regeneration, risk factors, pharmacological treatments, prevention and the effects of diet, focusing in this case on compounds present in a diet that could have palliative and preventive effects and could be used as concomitant treatments to drugs, which are and should always be the first option. It should be noted as a concluding remark that non-pharmacological treatments such as diet and exercise have, or should have, a relevant role in supporting pharmacology, which is the recommended prescription today, but we cannot ignore that they can have a great relevance in the treatment of this disease.

Optimized automated radiosynthesis of 18F-JNJ64413739 for purinergic ion channel receptor 7 (P2X7R) imaging in osteoporotic model rats

Objective

To optimize the automated radiosynthesis of the purinergic ion channel receptor 7 (P2X7R) imaging agent 18F-JNJ64413739 and evaluate its potential for brain imaging in osteoporotic model rats.

Methods

A more electron-deficient nitropyridine was employed as the labeling precursor to facilitate the 18F-labeling. The radiosynthesis was conducted on an AllinOne synthesis module, and followed by purification via high-performance liquid chromatography (HPLC). The resulting 18F-JNJ64413739 was subjected to quality control tests. Small-animal PET/CT imaging studies were performed in sham and osteoporotic model rats.

Results

The optimized automated radiossynthesis of 18F-JNJ64413739 was successfully completed in approximately 100 min with non-decay-corrected radiochemical yield of 6.7% ± 3.8% (n = 3), >97% radiochemical purity and >14.3 ± 1.3 GBq/μmol molar activity. The product met all clinical quality requirements. 18F-JNJ64413739 PET/CT imaging showed revealed significantly higher radioactivity uptake in various brain regions of the osteoporotic model rats compared to sham control group.

Conclusion

We successfully optimized the automated radiosynthesis of 18F-JNJ64413739. The resulting tracer not only met clinical quality requirements but also demonstrated potential for clinical application in the diagnosis of osteoporosis, as evidenced by higher radioactivity uptake in various brain regions of osteoporotic model rats compared to normal controls.

Impact of SARS-CoV-2 infection on patients with myasthenia gravis: a retrospective study in a Chinese population

Background and purpose

Myasthenia gravis (MG) is characterized by fluctuating muscle weakness due to immune-mediated damage to acetylcholine receptors. Viral infections can exacerbate symptoms of muscle weakness, and the clinical status of patients with MG may influence the outcomes of such infections. Here, we identified factors of symptom exacerbation, severe SARS-CoV-2 infection, and pneumonia in patients with MG who are infected with SARS-CoV-2.

Methods

The clinical characteristics and outcomes of 341 MG patients infected with SARS-CoV-2 across multiple regions in China were determined.

Results

The median age of the patients was 49 years (range: 35-60 years) and the median disease duration was 4 years (range: 2-8 years). Among the patients, 67 (49.0%) were male and 174 (51.0%) were female. Multivariate analysis indicated that thymectomy [OR, 1.654 (95% CI, 1.036-2.643); p = 0.035], severe SARS-CoV-2 infection [OR, 4.275 (95% CI, 2.206-8.286); p < 0.001], and pyridostigmine bromide [OR, 1.955 (95% CI, 1.192-3.206); p = 0.008] were associated with exacerbation of MG symptoms in patients infected with SARS-CoV-2. Age was significantly associated with severe SARS-CoV-2 infection [OR, 1.023 (95% CI, 1.001-1.046); p = 0.008], while patients with cardiac/vascular comorbidities exhibited an increased likelihood of severe SARS-CoV-2 infection [OR, 3.276 (95% CI, 1.027-10.449); p = 0.045]. Likewise, steroid treatment [OR, 6.140 (95% CI, 2.335-16.140); p < 0.001] was associated with a significantly increased likelihood of severe SARS-CoV-2 infection compared with symptomatic treatment. Additionally, gender [OR, 0.323 (95% CI, 0.120-0.868); p = 0.025] and SARS-CoV-2 severity [OR, 6.067 (95% CI, 1.953-18.850); p = 0.002] were associated with the occurrence of pneumonia.

Conclusion

We identified factors that were associated with the exacerbation of MG symptoms in patients infected with SARS-CoV-2, including thymectomy, severe SARS-CoV-2 infection, and the use of pyridostigmine bromide. Due to the retrospective nature of the study, these findings should be interpreted as associations rather than predictive factors. However, the results confirm the established relationships between severe SARS-CoV-2 infection and age, cardiovascular comorbidities, and the use of steroid treatment, suggesting that these factors should be considered when managing MG patients during SARS-CoV-2 infection.

The pivotal role of the Hes1/Piezo1 pathway in the pathophysiology of glucocorticoid-induced osteoporosis

Glucocorticoid-induced osteoporosis (GIOP) lacks fully effective treatments. This study investigated the role of Piezo1, a mechanosensitive ion channel component 1, in GIOP. We found reduced Piezo1 expression in cortical bone osteocytes from patients with GIOP and a GIOP mouse model. Yoda1, a Piezo1 agonist, enhanced the mechanical stress response and bone mass and strength, which were diminished by dexamethasone (DEX) administration in GIOP mice. RNA-seq revealed that Yoda1 elevated Piezo1 expression by activating the key transcription factor Hes1, followed by enhanced CaM kinase II and Akt phosphorylation in osteocytes. This improved the lacuno-canalicular network and reduced sclerostin production and the receptor activator of NF-κB/osteoprotegerin ratio, which were mitigated by DEX. Comparative analysis of mouse models and human GIOP cortical bone revealed downregulation of mechanostimulated osteogenic factors, such as osteocrin, and cartilage differentiation markers in osteoprogenitor cells. In human periosteum-derived cells, DEX suppressed differentiation into osteoblasts, but Yoda1 rescued this effect. Our findings suggest that reduced Piezo1 expression and activity in osteocytes and periosteal cells contribute to GIOP, and Yoda1 may offer a novel therapeutic approach by restoring mechanosensitivity.

Protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell injury and the underlying mechanism

OBJECTIVE

To investigate the protective effects of Gumibao recipe on glucocorticoid-included bone microcirculatory endothelial cell (BMEC) injury, and elucidate the possible underlying mechanism.

METHODS

BMECs were treated with different concentrations of hydrocortisone at different time points, and the viability as well as migration of BMECs were evaluated; furthermore, the release of LDH, levels of VEGF, PAI-1, t-PA, and the content of NO by BMECs have been evaluated by commercially available kits; moreover, the expressions of eNOS, p-PI3K, p-Akt and p-mTOR in BMECs were examined by WB methods. Next, hydrocortisone treated BMECs were co-treated with Gumibao recipe, and the viability, migration and autophagy of BMECs were evaluated.

RESULTS

0.2 mg/ml and 0.3 mg/ml hydrocortisone significantly decreased viability and migration ability of BMECs, and also impeded the endothelial function of BMECs by decreasing the levels of VEGF, t-PA, the content of NO, and increasing the level of PAI-1. Gumibao medicated serum markedly increased the viability and migration of BMECs, and also increased the levels of VEGF, t-PA, the content of NO, meanwhile decreased the level of PAI-1 in 0.3 mg/ml hydrocortisone treated BMECs; moreover, glucocorticoids inhibited the autophagy of BMECs, and Gumibao recipe significantly increased the autophagy of BMECs; meanwhile, autophagy inhibitor 3-MA partially blocked the protective effects of Gumibao recipe. Finally, gumibao recipe partially abrogated the inhibitory effects of hydrocortisone on the activation of PI3K/Akt/mTOR singling, and these effects were further counteracted by PI3K and mTOR inhibitor NVP-BEZ235.

CONCLUSIONS

We reported for the first time the protective effects of Gumibao recipe on glucocorticoid-included BMECs injury, and the possible underlying mechanism may be regulating the autophagy of BMECs via PI3K/AKT/mTOR signaling pathway.

Biological Heterogeneity in Susceptibility to Glucocorticoid-Induced Bone Loss: Short- and Long-Term Hip BMD Trajectories

CONTEXT

Glucocorticoids (GCs) are widely used for their anti-inflammatory and immunosuppressive properties. Their effect on bone health is predominantly negative by decreasing bone formation and increasing risk of fractures.

OBJECTIVE

This work aimed to quantify the short- and long-term changes in total hip bone mineral density (THBMD) after initiating systemic GC treatment in previously GC treatment-naive adults without bone protective agents.

METHODS

An observational study was conducted using THBMD data from dual-energy x-ray absorptiometry (DXA). Individuals were stratified by sex and tertiles of GC exposure. Individuals not GC-exposed served as a reference group. Routine-care DXA scans were obtained from the main public hospitals servicing the Island of Funen in Denmark. A total of 15 099 adults underwent routine DXA at Odense University Hospital between 2006 and 2021. Data were enriched with Danish national registers. Intervention included systemic GCs (observational data). The short-term outcome included annualized THBMD changes between first 2 DXA scans. The long-term outcome included greater than 5% annualized THBMD loss over a 10-year follow-up.

RESULTS

Strong associations between GC exposure and THBMD loss was found for both outcomes, with larger losses in the middle and upper tertiles of GC exposure. The risk of experiencing greater than 5% annualized THBMD loss was elevated, especially in the first 2 years of initiating GC treatment. There is significant heterogeneity in THBMD responses, with approximately 1 in 5 patients experiencing no nominal bone loss despite receiving upper tertile levels of GC exposure.

CONCLUSION

The findings confirm the association between initial GC exposure and significant bone loss. The heterogeneity in individual responses emphasizes the need for early monitoring and personalized approaches in managing bone health for patients undergoing GC treatment.

Mild Autonomous Cortisol Secretion (MACS) - Related Osteoporosis

Mild autonomous cortisol secretion (MACS) has thus far been associated with several comorbidities, among which osteoporosis and fractures appear to be highly prevalent. Recent guidelines for adrenal incidentalomas have updated the definition of MACS, currently formulated on serum cortisol after a 1-mg dexamethasone test above 1.8 µg/dL or 50 nmol/L. Previous studies on bone health in adrenal incidentalomas had adopted different definitions of MACS, producing heterogeneous results in terms of fracture prevalence. This review aims to summarize the clinical impact of MACS in relation to fractures, bone quantity and quality, by providing a thorough update on MACS-related osteoporosis (MACS-ROP). This area has a large room for research, and management of this comorbidity still needs to be elucidated.