Treating osteoporosis to prevent fractures: current concepts and future developments

Heme metabolism mediates RANKL-induced osteoclastogenesis via mitochondrial oxidative phosphorylation

Bone undergoes life-long remodeling, in which disorders of bone remodeling could occur in many pathological conditions including osteoporosis. Understanding the cellular metabolism of osteoclasts (OCs) is key to developing new treatments for osteoporosis, a disease that affects over 200 million women worldwide per annum. We found that human OC differentiation from peripheral blood mononuclear cells derived from 8 female patients is featured with a distinct gene expression profile of mitochondrial biogenesis. Elevated mitochondrial membrane potential (MMP, Δψm) was also observed in receptor activator of NF-κB ligand (RANKL)-induced OCs. Interestingly, the gene pathways of heme synthesis and metabolism were activated upon RANKL stimulation, featured by transcriptomic profiling in murine cells at a single-cell resolution, which revealed a stepwise expression pattern of heme-related genes. The real-world human data also divulges potential links between heme-related genes and bone mineral density. Heme is known to have a role in the formation of functional mitochondrial complexes that regulate MMP. Disruption of heme biosynthesis via genetically silencing Ferrochelatase or a selective inhibitor, N-methyl Protoporphyrin IX (NMPP), demonstrated potent inhibition of OC differentiation, with a dose-dependent effect observed in NMPP treatment and a substantial efficacy even at a single dose. In vivo study further showed the protective effect of NMPP on ovariectomy-induced bone loss in female mice. Collectively, we found that RANKL-mediated signaling regulated mitochondrial formation and heme metabolism to synergistically support osteoclastogenesis. Inhibition of heme synthesis impaired OC formation and reversed excessive bone loss, representing a new therapeutic target for metabolic skeletal disorders.

Global burden of vertebral fractures from 1990 to 2021 and projections for the next three decades

BACKGROUND

Vertebral fractures are linked to significant disability and mortality risks. Yet, existing studies on their global burden are outdated and lack predictive foresight.

METHODS

Public data from the 2021 GBD study were analyzed to assess the global burden and epidemiological trends of vertebral fractures. The annual percentage change (EAPC) was calculated to represent temporal trends from 1990 to 2021. Machine learning was used to predict the global burden of vertebral fractures over the next 30 years.

RESULTS

From 1990 to 2021, the global burden of vertebral fractures significantly decreased. The age-standardized incidence rates (ASIR) showed the largest decline in Eastern Sub-Saharan Africa (EAPC: -1.5; 95% CI: -2.0 to -1.0), while North Africa and the Middle East were the only regions to report an increase (EAPC: 0.3; 95% CI: 0.1 to 0.5). For age-standardized prevalence rates (ASPR), High-income Asia Pacific saw the steepest decline (EAPC: -1.4; 95% CI: -1.5 to -1.2), while the Caribbean experienced the largest increase (EAPC: 0.8; 95% CI: 0.4 to 1.3). Similarly, in terms of age-standardized years lived with disability rates (ASYR), the most substantial reduction occurred in High-income Asia Pacific (EAPC: -1.4; 95% CI: -1.5 to -1.3), with the Caribbean again showing the greatest rise (EAPC: 0.8; 95% CI: 0.3 to 1.2). Males generally exhibited higher age-standardized rates (ASRs) than females, although females aged 65-70 years old surpassed males. Predictive models suggest continued declines in global ASIR, ASPR, and ASYR by 2050.

CONCLUSIONS

Our study shows a steady reduction in the global burden of vertebral fractures from 1990 to 2021. Nevertheless, disparities remain across regions, with a positive correlation between ASRs with SDI.

Glutamine Promotes Rotator Cuff Healing by Ameliorating Age-Related Osteoporosis

BACKGROUND

Age-related osteoporosis complicates rotator cuff tear (RCT) treatment, undermining the integrity of surgical anchor fixation during rotator cuff repair (RCR). This study aimed to investigate whether supplementation with glutamine, an intrinsic amino acid crucial in cell metabolism, can enhance rotator cuff healing by ameliorating age-associated osteoporosis.

METHODS

Forty-eight female Sprague-Dawley rats were divided into 4 groups: (1) young control (sham surgery), (2) aged control (sham surgery), (3) aged-RCT (RCR with fibrin), and (4) aged-RCT-Gln (RCR with glutamine-enriched fibrin). RCR was performed bilaterally on rats in the RCT groups, with subsequent application of the respective fibrin gel at the tendon-bone interface. Evaluations included micro-computed tomography (CT) for bone quality, histology and immunohistochemistry for tissue integrity, and biomechanical testing for tendon-bone complex strength.

RESULTS

Micro-CT revealed worse bone quality at the proximal humerus in the aged rats compared with the young rats, confirming spontaneous osteoporosis occurring with age. Glutamine supplementation improved bone quality in the aged-RCT-Gln group compared with the aged-RCT group, with significantly higher mean bone volume/total volume fraction (BV/TV) (28.69% ± 3.1% compared with 21.13% ± 3.9%), trabecular number (Tb.N) (1.88 ± 0.18 compared with 1.55 ± 0.21 mm -1 ), and trabecular thickness (Tb.th) (0.15 ± 0.03 compared with 0.12 ± 0.02 mm) and lower trabecular separation (Tb.sp) (0.19 ± 0.03 compared with 0.22 ± 0.03 mm). Histological and immunohistological analysis demonstrated enhanced bone regeneration and a more organized tendon-cartilage-bone interface in the aged-RCT-Gln group. Biomechanical analysis also revealed a more resilient tendon-bone complex after glutamine supplementation.

CONCLUSIONS

Osteoporosis occurred spontaneously at the proximal humerus with age. Glutamine supplementation effectively mitigated age-related osteoporosis and enhanced RCR in elderly rats. These findings support the potential of glutamine, the most abundant amino acid in the body, as a valuable therapeutic intervention for improving RCT outcomes in the aging population, warranting further investigation in clinical settings.

CLINICAL RELEVANCE

Glutamine supplementation may be a novel therapeutic strategy to enhance RCR in elderly patients with osteoporosis.

Implementing a Clinical Risk Assessment Tool to Improve Bone Health in Postmenopausal Women

OBJECTIVE

To improve staff knowledge of osteoporosis and increase the identification of fracture risk in postmenopausal women by implementing use of the Fracture Risk Assessment Tool (FRAX) in an outpatient setting.

DESIGN

Quality improvement project guided using the Plan-Do-Study-Act cycle.

SETTING/LOCAL PROBLEM

In a low-income primary care clinic, no standardized fracture risk assessment tool was being used, leading to inconsistency in referrals for dual-energy X-ray absorptiometry (DXA).

PARTICIPANTS

Office staff and postmenopausal women ages 50 to 64 years.

INTERVENTIONS/MEASUREMENTS

A standardized process was designed to promote appropriate osteoporosis management to improve the assessment, diagnosis, and treatment of osteoporosis in postmenopausal women. Staff training was provided before project implementation. Outcome measures included pre-post Revised Osteoporosis Knowledge Test, FRAX adherence, and DXA referrals.

RESULTS

Staff knowledge improved by 25.8% after completion of staff training. During the 2-month implementation period, FRAX adherence was 96.3% (n = 156) among the 162 eligible women, and 98.6% of DXA referrals (n = 70) were completed for the 71 women identified with a major osteoporotic fracture risk greater than 8.4%.

CONCLUSION

With this quality improvement project, we successfully implemented the FRAX tool in the outpatient setting. Initial high adherence rates for FRAX screenings and DXA referrals demonstrated advancements made in clinical practice to provide evidence-based care to postmenopausal women at the greatest risk for an osteoporotic fracture.

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.

Curcumin Ameliorated Glucocorticoid-Induced Osteoporosis While Modulating the Gut Microbiota and Serum Metabolome

Glucocorticoid-induced osteoporosis (GIOP) is the leading cause of secondary osteoporosis. Recently, the "bone-gut axis" theory has linked bone development with gut microbial diversity, community composition, and metabolites. Curcumin, a well-studied polyphenol, shows potential in mitigating bone loss and osteoporosis. Alendronate, a standard therapeutic agent for osteoporosis, serves as a positive control in this investigation. The study demonstrates the potency of curcumin in reducing bone loss and restoring bone mineral density, enhancing trabecular parameters notably through increased trabecular number, volume, and thickness and reduced bone marrow cavity size. Gut microbiome sequencing revealed that both curcumin and alendronate treatments similarly enhanced gut microbial diversity and altered microbiota composition, increasing beneficial bacteria (Akkermansia_muciniphila, Dubosiella_sp910585105, and Ruminococcus_sp910584195) while reducing harmful bacteria (Treponema_D_sp910584475 and Duncaniella_sp910584825). Furthermore, significant changes in serum levels of metabolites including raffinose, ursolic acid, spermidine, inosine, hypoxanthine, thiamine, and pantothenic acid were observed post-treatment with curcumin or alendronate. Importantly, these beneficial metabolites and microorganisms were negatively correlated with inflammatory cytokines. In conclusion, curcumin holds promise for use against GIOP by modulating the gut microbiome and serum metabolome as well as reducing systemic inflammation.

Risk factors for non-vertebral fractures in community-dwelling elderly: a 10-year follow-up study in New Zealand

This 10-year study of 5000 + adults aged 50-84 found 20% experienced non-vertebral fractures. Higher risk was linked to female sex, older age, European ethnicity, lower education, living alone, alcohol use, prior falls/fractures, osteoporosis, arthritis, and antidepressants. Targeting modifiable factors (living arrangements, alcohol, antidepressants) could reduce fracture burden cost-effectively in older adults.

BACKGROUND

Although there has been extensive research on non-vertebral fractures, their risk factors remain incompletely understood. This study aimed to examine risk factors associated with non-vertebral fractures through a longitudinal examination of a community-dwelling cohort.

METHODS

This was a follow-up of participants recruited from family practices into a randomized trial of vitamin D supplementation and interviewed between 2011 and 2012, with follow-up until 2022. The outcome was the first non-vertebral fracture during the follow-up period, as identified from hospital events and insurance claims for fractures. Candidate risk factors were selected using a domain-based approach, and Cox models were employed to estimate adjusted hazard ratios (HRs).

RESULTS

The analysis comprised 5108 participants aged 50-84 years. Of these, 83% were of European/other ethnicity. A substantial proportion reported living with non-family members or living alone (20.5%), engaging in daily drinking (21.6%), or using antidepressants (11.9%). Over a median 10-year follow-up, 1016 participants (20%) experienced non-vertebral fractures. In the multivariable model, several factors were related to higher risk of non-vertebral fracture, including females (HR = 1.53), aged 80-84 years (HR = 1.47), European/other ethnicity, primary school education (HR = 1.65), living with non-family members (HR = 1.47) or living alone (HR = 1.29), daily alcohol drinking (HR = 1.51), history of falls (HR = 1.59) or fractures (HR = 1.43), osteoporosis (HR = 1.95), and arthritis (HR = 1.20), and dispensing of antidepressants (HR = 1.52) and antiarrhythmic medications (HR = 1.51).

CONCLUSION

Non-vertebral fractures are prevalent among older adults, with several prevalent and potentially modifiable risk factors identified, such as living situation, drinking habits, and antidepressant dispensing. Further exploration of these factors' causality and the implementation of public health interventions targeting them, could yield significant benefits and cost-effectively reduce the burden of fractures.

TRIAL REGISTRATION

This study was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000402943).

U-Net-Based Deep Learning Hybrid Model: Research and Evaluation for Precise Prediction of Spinal Bone Density on Abdominal Radiographs

Osteoporosis is a metabolic bone disorder characterized by the progressive loss of bone mass, which significantly increases the risk of fractures. While dual-energy X-ray absorptiometry is the standard technique for assessing bone mineral density, its use is limited in high-risk female populations. Additionally, quantitative computed tomography offers three-dimensional evaluations of bone mineral density but is costly and prone to motion artifacts. To overcome these limitations, this study proposes a hybrid model integrating U-Net and artificial neural networks, specifically focusing on abdominal X-ray images in the anteroposterior view for detailed skeletal analysis and improved accuracy in L2 vertebra mineral density measurement. The model targets female patients, who are at a higher risk for spinal disorders and osteoporosis. The U-Net model is employed for image preprocessing to reduce background noise and enhance bone tissue features, followed by analysis with the artificial neural network model to predict bone mineral density through nonlinear regression. The performance of the model, demonstrated by a high correlation coefficient of 0.77 and a low mean absolute error of 0.08 g per square centimeter, highlights its significance and effectiveness, particularly in comparison to dual-energy X-ray absorptiometry.

Ganoderic Acid A Prevented Osteoporosis by Modulating the PIK3CA/p-Akt/TWIST1 Signaling Pathway

Osteoporosis is a disorder of decreased bone mass, microarchitectural deterioration, and fragility fractures. Ganoderma lucidum has been reported to have a variety of pharmacological activities, including immune regulation, anti-inflammation, antioxidation, sedative hypnosis, blood sugar and lipid regulation, and so on. However, the effective ingredients and the underlying mechanism of Ganoderma lucidum against osteoporosis are rarely clarified. Ganoderic acid A (GA-A), a triterpenoid, is one of the main components of Ganoderma lucidum. Our previous preliminary bioinformatic study found that it may affect bone metabolism, and it has been reported that GA-A has anti-osteoporosis potential via regulating MC3T3-E1 cells' osteogenic differentiation activity. Therefore, the aim of this study is to investigate the effects of Ganoderic acid A in preventing osteoporosis and uncover the potential mechanisms. In vivo, the 8-week-old C57BL/6J female mice were used to establish the osteoporosis model by ovariectomy (OVX). Two cell lines, MC3T3-E1 cells and primary osteoblasts, were used and induced with hydrogen peroxide (H2O2) to the state of oxidative stress in osteoporosis in vitro. We showed that Ganoderic acid A could inhibit OVX-induced bone loss in a dose-dependent manner and promote H2O2-induced osteogenic differentiation of primary osteoblasts and MC3T3-E1 cells. The mechanism-related signaling pathways were identified by network pharmacology screening and verified by bioinformatics. Results predicted that the target of Ganoderic acid A might be PIK3CA. Mechanistically, we found that PIK3CA activated the Akt receptor, then inhibited the expression of TWIST1 in the osteoblasts to up-regulate the protein expression of the osteogenic-related markers. Our results suggested that Ganoderic acid A could prevent OVX-induced osteoporosis and promote H2O2-induced osteogenic differentiation of primary osteoblasts and MC3T3-E1 cells. Ganoderic acid A might play an important role in the prevention of osteoporosis by modulating the PIK3CA/p-Akt/TWIST1 signaling pathway.

In vitro Bone Tissue Engineering Strategies: The Relevance of Cells and Culturing Methods in Bone Formation and Remodeling

The most recent advances in bone tissue engineering (BTE) approaches step forward in the field of three-dimensional (3D) tissue models, enabling the development of more realistic tools to study bone disorders, such as osteoporosis. BTE field aims to mimic native bone tissue more truthfully, providing an appropriate environment for tissue regeneration and repair through the combination of 3D porous scaffolds, specific growth factors, and cells. Currently, the scientific community is focused on developing and improving new biomaterials that in combination with growth factors and specific cell types, that can accurately emulate the native bone microenvironment. However, most of the reported studies in the BTE field are focused on bone formation, disregarding the entire bone remodeling steps, which also involve bone resorption. In this review, the currently available mono and co-culturing methods, types of biomaterials used in several strategies that combine scaffolds and relevant cells (e.g., osteoblasts (OBs), osteoclasts (OCs), and osteocytes (OCys)), envisioning a healthy bone formation and remodeling process, the gold-standard drug delivery systems, and bioengineered-based systems to tackle bone diseases are described.

A novel hybrid deep learning framework based on biplanar X-ray radiography images for bone density prediction and classification

This study utilized deep learning for bone mineral density (BMD) prediction and classification using biplanar X-ray radiography (BPX) images from Huashan Hospital Medical Checkup Center. Results showed high accuracy and strong correlation with quantitative computed tomography (QCT) results. The proposed models offer potential for screening patients at a high risk of osteoporosis and reducing unnecessary radiation and costs.

PURPOSE

To explore the feasibility of using a hybrid deep learning framework (HDLF) to establish a model for BMD prediction and classification based on BPX images. This study aimed to establish an automated tool for screening patients at a high risk of osteoporosis.

METHODS

A total of 906 BPX scans from 453 subjects were included in this study, with QCT results serving as the reference standard. The training-validation set:independent test set ratio was 4:1. The L1-L3 vertebral bodies were manually annotated by experienced radiologists, and the HDLF was established to predict BMD and diagnose abnormality based on BPX images and clinical information. The performance metrics of the models were calculated and evaluated.

RESULTS

TheR 2 values of the BMD prediction regression model in the independent test set based on BPX images and multimodal data (BPX images and clinical information) were 0.77 and 0.79, respectively. The Pearson correlation coefficients were 0.88 and 0.89, respectively, with P-values < 0.001. Bland-Altman analysis revealed no significant difference between the predictions of the models and QCT results. The classification model achieved the highest AUC of 0.97 based on multimodal data in the independent test set, with an accuracy of 0.93, sensitivity of 0.84, specificity of 0.96, and F1 score of 0.93.

CONCLUSION

This study demonstrates that deep learning neural networks applied to BPX images can accurately predict BMD and perform classification diagnoses, which can reduce the radiation risk, economic consumption, and time consumption associated with specialized BMD measurement.

VGF and the VGF-derived peptide AQEE30 stimulate osteoblastic bone formation through the C3a receptor

New therapeutic targets, especially those that stimulate bone formation in cortical bone, are needed to overcome the limitations of current antiosteoporotic drugs. We previously demonstrated that factors secreted from megakaryocytes (MKs) promote bone formation. Here we conducted a proteomic analysis to identify a novel bone-forming factor from MK secretions. We revealed that Vgf, a nerve growth factor-responsive gene, and its derived active peptide AQEE30 in MK-conditioned medium play important roles in osteoblast proliferation and in vitro bone formation. In both Vgf-deficient male and female mice, the cortical bone mass was significantly decreased due to reductions in osteoblast number and bone formation activity. AQEE30 stimulated intracellular cyclic adenosine monophosphate (cAMP) levels and protein kinase A (PKA) activity in osteoblasts, whereas an adenylyl cyclase inhibitor blocked AQEE30-stimulated osteoblast proliferation and in vitro bone formation. Complement C3a receptor-1 (C3AR1) was expressed and interacted with AQEE30 in osteoblasts, and C3AR1 inhibition blocked all AQEE30-induced changes, including stimulated proliferation, bone formation and cAMP production, in osteoblasts. Injecting mini-PEGylated AQEE30 into calvaria increased the number of osteocalcin-positive cells and new bone formation. In conclusion, this study reveals a novel role of VGF in bone formation, particularly in cortical bone, and shows that AQEE30, a VGF-derived peptide, mediates this role by activating cAMP-PKA signaling via the C3AR1 receptor in osteoblasts.

Associations of osteoarthritis with risk of future fracture events: prospective study in UK Biobank

BACKGROUND

Researchers have long been interested in the potential relationship between osteoarthritis (OA), falls, and fractures; however, the evidence supporting this relationship has been conflicting. This study aimed to investigate the association between osteoarthritis and future fracture events.

MATERIALS AND METHODS

This study was designed as a prospective cohort study. We recruited a total of 440 476 individuals from the UK Biobank to investigate the impact of OA on the incidence of fracture. Among the total population, there were 54 581 participants diagnosed with OA. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

A total of 26 083 fracture events were documented over a median follow-up period of 13.5 years. After multivariable adjustment, participants with osteoarthritis had an HR (95% CI) of 1.11 (1.08, 1.15) for future fracture events compared to participants without osteoarthritis ( P  < 0.0001). Falls explained 16.34% of the association between osteoarthritis and fracture events and 14.15% of the association between knee osteoarthritis and fracture events. The association was not substantially altered across the series of sensitivity analyses.

CONCLUSION

Osteoarthritis was associated with a greater risk of future fracture events. This finding highlights the importance of preventing future fracture events in people with osteoarthritis.

Enhanced Osteoporosis Treatment via Nano Drug Coating Encapsulating Lactobacillus rhamnosus GG

Osteoporosis is the most common systemic skeletal disorder, particularly associated with aging and postmenopausal women. With the growing knowledge about the gut-bone axis, the therapeutic strategies for osteoporosis have been shifted toward regulating gut microbiota to promote positive bone metabolism. AlthoughLactobacillus rhamnosus GG (LGG) is widely reported to positively regulate bone metabolism by restoring the dysbiotic microbiome, oral administration is associated with sensitivity to gastric fluid and low bioavailability. Other studies also demonstrated that bisphosphonates ameliorate osteoporosis by directly regulating bone metabolism, especially inhibiting osteoclast activity. However, the side effects caused by bisphosphonate treatment still represent a significant problem. In this study, we assembled alendronate, a clinically used bisphosphonate, with DSPE-phospholipid nanoencapsulation and LGG (ADB), to protect LGG from the acidic environment of the stomach, while simultaneously reducing the gastrointestinal side effects associated with the oral administration of alendronate. We further investigated the potential of these DSPE-phospholipid nanoencapsulated bacteria ADB to repair osteoporotic bone deterioration, and their ability to regulate gut microbiota in vivo, which is strongly associated with the intrinsic environment. Compared with the same dosage of LGG and alendronate alone, ADB positively regulated bone metabolism, and osteoporosis was significantly revised in ovariectomized mice models.

A Real-Life Study in Sequential Therapy for Severe Menopausal Osteoporosis

Background: Teriparatide (TPT) acts against severe primary (postmenopausal) osteoporosis (MOP), and it requires continuation with another anti-resorptive drug to conserve or enhance the effects on fracture risk reduction. Objective: To analyse the sequential pharmacotherapy in MOP who were treated upon a 24-month daily 20 µg TPT protocol (24-mo-TPT) followed by another 12 months of anti-resorptive drugs (12-mo-AR) amid real-life settings. Hypotheses: 1. TPT candidates had a more severe fracture risk profile versus those who did not fulfil the TPT criteria according to the national protocol of TPT initiation; 2. Patients treated with TPT improved their DXA profile after 24 mo; 3. After 1 year of therapy since the last TPT injection, the improved bone profile and fracture risk at the end of the TPT protocol were conserved; 4. The mineral metabolism assays and fracture risk status were similar at TPT initiation between those who finished the 24 mo protocol and those who prematurely stopped it. Methods: This was a longitudinal, retrospective, multicentre study in MOP. The entire cohort (group A) included the TPT group (B) versus the non-TPT group (non-B). Group B included subjects who finished 24-mo-TPT (group P) and early droppers (ED), and then both continued 12-mo-AR. Results: Group B (40.5%) from cohort A (N = 79) vs. non-B had lower T-scores, increased age and years since menopause. A similar profile of demographic features, BTM, and prevalent fractures (73%, respectively, 57%) was found in group P (72%) vs. ED (21.8%). Group P: osteocalcin was statistically significantly higher at 12 mo (+308.39%), respectively, at 24 mo (+171.65%) vs. baseline (p < 0.001 for each), while at 12-mo-AR became similar to baseline (p = 0.615). The cumulative probability of transient hypercalcemia-free follow-up of protocol had the highest value of 0.97 at 6 mo. An incidental fracture (1/32) was confirmed under 24-mo-TPT. BMD had a mean percent increase at the lumbar spine of +8.21% (p < 0.001), of +12.22% (p < 0.001), respectively, of +11.39% (p < 0.001). The pharmacologic sequence for 12-mo-AR included bisphosphonates (24.24% were oral BP) or denosumab (13%). BTM showed a suppression at 12-mo-AR (p < 0.05), while all BMD/T-scores were stationary. No incidental fracture was registered during 12-mo-AR. Conclusions: All research hypotheses were confirmed. This study in high-risk MOP highlighted an effective sequential pharmacotherapy in reducing the fracture risk as pinpointed by BMD/T-score measurements and analysing the incidental fractures profile.

Clinical and demographic factors determining patient fracture risk decision point (FRDP): The improving risk communication in osteoporosis (RICO) project

This study aims to understand how osteoporosis medication acceptance varies across countries with differing guidance on treatment threshold and influence of clinical and demographic factors. A total of 79.2% accepted treatment at a fracture probability at or below the treatment threshold. Fracture history and age did not strongly impact acceptance, suggesting a need for improved fracture risk communication.

PURPOSE

This part of the Improving Risk Communication in Osteoporosis (RICO) study aims to understand patients' willingness to initiate osteoporosis treatment given a hypothetical fracture probability-derived from the FRAX® Risk Assessment Tool-and how age, fracture history, and numeric literacy may influence this.

METHODS

In 2022-2023, 332 postmenopausal women at risk of fracture were interviewed from nine countries to determine participants' Fracture Risk Decision Point (FRDP), the lowest probability of major osteoporotic fracture at which they would accept an osteoporosis medication. Participants' FRDP was evaluated given eight hypothetical 10-year FRAX scores.

RESULTS

In countries with FRAX-based treatment thresholds, over half of the participants per country reported an FRDP that was below the threshold. Collectively, 79.2% demonstrated FRDPs at or below their respective threshold. Age and fracture history did not have a strong influence on FRDP; however, those who demonstrated higher levels of numeric literacy reported a significantly higher median FRDP (10%) compared to those who showed lower levels (5%, p < 0.001).

CONCLUSIONS

Most patients were willing to accept an osteoporosis medication prescription at a hypothetical FRAX probability that was even lower than that of their nationally recommended treatment threshold. Literacy scores had a significant influence on FRDP whereas age and fracture history did not.

Pharmacology and mechanisms of apigenin in preventing osteoporosis

Osteoporosis (OP) stands as the most prevalent systemic skeletal condition associated with aging. The current clinical management of OP predominantly depends on anti-resorptive and anabolic agents. Nevertheless, prolonged use of some of these medications has been observed to reduce efficacy and elevate adverse effects. Given the necessity for sustained or even lifelong treatment of OP, the identification of drugs that are not only effective but also safe and cost-efficient is of utmost significance. As disease treatment paradigms continue to evolve and recent advancements in OP research come to light, certain plant-derived compounds have emerged, presenting notable benefits in the management of OP. This review primarily explores the pharmacological properties of apigenin and elucidates its therapeutic mechanisms in the context of OP. The insights provided herein aspire to offer a foundation for the judicious use of apigenin in forthcoming research, particularly within the scope of OP.

Effects of Synbiotic Supplementation on Bone and Metabolic Health in Caucasian Postmenopausal Women: Rationale and Design of the OsteoPreP Trial

BACKGROUND/OBJECTIVES

Correction of decreased diversity of the gut microbiome, which is characteristic of menopause, by supplementation with a synbiotic may attenuate or prevent dysbiosis processes and preserve bone mass. We describe the rationale and design of the OsteoPreP trial aimed at evaluating the effects of 12 months of supplementation with a synbiotic on bone and metabolic health in postmenopausal Caucasian women.

METHODS

This is a randomized, double-blinded, placebo-controlled trial among 160 Caucasian, postmenopausal women with no current diagnosis of osteoporosis or supplementation with pro- or prebiotics, and no medical treatment affecting bone turnover. Dual-energy X-ray absorptiometry scans will be conducted at screening to confirm absence of osteoporosis. The primary outcome is the relative change (%) in total bone mineral density of the distal tibia at 12 months post-treatment between the active and placebo groups, as determined via high-resolution peripheral quantitative computed tomography. Secondary outcomes are the effects on immune system modulation and cognition, gut microbiota composition, and musculoskeletal and metabolic functions, with particular emphasis on blood glucose regulation.

CONCLUSIONS

The trial will inform on the efficacy and safety of a synbiotic containing both aerobic and anerobic bacterial strains and a prebiotic fiber on reduction in bone loss and on indices of blood glucose regulation. This trial may pave the way for an exciting field of translational research and be the underpinnings of the prevention strategy of osteoporosis and the management of metabolic dysfunction in postmenopausal women. The trial is registered with clinicaltrials.gov (NCT05348694).

Hidden blood loss of minimally invasive transforaminal lumbar interbody fusion of lumbar degenerative diseases in patients with osteoporosis: a retrospective study

BACKGROUND

To compare hidden blood loss (HBL) of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) of lumbar degenerative diseases in patients with or without osteoporosis (OP) and identify the risk factors for HBL with OP.

METHODS

The data from 156 patients with lumbar degenerative diseases, who underwent Mis-TLIF between January 2018 and December 2021, were retrospectively analyzed. The patients were divided into the Osteoporosis and Non-osteoporosis groups. We recorded demographic characteristics and blood-related parameters in each group. Blood loss was measured by quantifying visible blood loss and calculating HBL using preoperative hematocrit (Hctpre) and postoperative hematocrit (Hctpost). Pearson or Spearman correlation analysis was used to investigate the association between OP patient's characteristics and HBL. Multivariate linear regression analysis was used to confirm independent risk factors of HBL in patients with OP.

RESULTS

The mean HBL of the Osteoporosis and Non-osteoporosis groups was 608.27 ± 175.23 and 173.04 ± 67.55 ml, respectively. There were significant differences in age, BMI, subcutaneous fat thickness, muscle thickness, Hctpost, average hematocrit of preoperative and postoperative (Hctave), visible blood loss, HBL and volume of allogeneic blood transfusions between the two groups (P < 0.05). Multivariate linear regression analysis showed that Hctpost, T-score, use of tranexamic acid (TXA) and preoperative regular anti-osteoporosis treatment were independent risk factors for HBL in patients with OP.

CONCLUSION

There was significant perioperative HBL in patients with OP. Hctpost, T-score, use of TXA and preoperative regular anti-osteoporosis treatment were independent risk factors for HBL in patients with OP. More attention should be paid to the perioperative period to ensure the safety of patients with OP.

Osteoporosis: a problem still faulty addressed by the Romanian healthcare system. Results of a questionnaire survey of people aged 40 years and over

Purpose

We aimed to investigate the knowledge and awareness level of osteoporosis, its risk factors, the possible causes of underdiagnosis, as well as the preventive measures and lifestyle behavior of the Romanian population.

Patients and methods

A non-interventional, cross-sectional study was performed, consisting of an in-person survey, in 10 pharmacies located in both urban and rural settings in Romania. The survey was distributed to patients ≥40 years old.

Results

Of 189 respondents, 78.8% were women, the majority age group being 60-69 (31.7%) and 50-59 (30.7%) years old and coming from urban areas (69.3%). Although 75.1% of participants declared knowing about osteoporosis, having a moderate level of knowledge, and women being more aware of the pathology, 77.3% have never performed a DXA test. Moreover, participants already diagnosed with osteoporosis did not show a better disease knowledge than those without a diagnosis. Nearly half of the respondents did not know that a family history of the disease increases the risk of developing it and 60% of them thought that symptoms may develop before a fracture occurs. The preventive strategies tend to be disregarded and thus, underused. Moreover, 42.9% of participants reported being diagnosed with osteoporosis, do not undergo treatment, although they are aware of the existence of effective strategies. The dataset was used to build a participant compatibility network. The network's clustering revealed six relevant communities, which are not correlated with questionnaire results but reflect the patterns of feature associations.

Conclusion

Preventive and therapeutic osteoporosis education programs are urgently needed in the Romanian population to decrease disability and high mortality risks and thus, to improve the quality of life.

Comparing the Efficacy of Antiosteoporotic Drugs in Preventing Periprosthetic Bone Loss Following Total Hip Arthroplasty: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND

Periprosthetic bone loss is a well-known phenomenon following total hip arthroplasty (THA). However, the choice of drugs for prevention remains controversial. Therefore, the aim of this study was to determine the best drug to treat periprosthetic bone loss by comparing changes in bone mineral density (BMD) at different times after THA.

METHODS

A comprehensive search of five databases and two clinical trial registration platforms was undertaken from their inception through to August 31, 2023 to identify eligible randomized controlled trials. A Bayesian network meta-analysis (NMA) was carried out for calculating the standardized mean difference (SMD) and the surface under cumulative ranking curve (SUCRA) of the BMD in calcar (Gruen zone 7) at 6 months, 12 months, and 24 months and over.

RESULTS

Twenty-nine trials involving 1427 patients and 10 different interventions were included. The results demonstrated that at 6 months, denosumab had the highest ranking (SUCRA = 0.90), followed by alendronate (SUCRA = 0.76), and zoledronate (SUCRA = 0.73). At 12 months, clodronate ranked highest (SUCRA = 0.96), followed by denosumab (SUCRA = 0.84) and teriparatide (SUCRA = 0.82). For interventions with a duration of 24 months and over, denosumab had the highest SUCRA value (SUCRA = 0.96), followed by raloxifene (SUCRA = 0.90) and zoledronate (SUCRA = 0.75).

CONCLUSION

Investigating the existing body of evidence revealed that denosumab demonstrates potential as an intervention of superior efficacy at the three specifically examined time points. However, it remains crucial to conduct further research to confirm these findings and determine the most effective treatment strategy.

The accuracy and clinical utility of spectral CT bone density measurement in the lumbar spine of unenhanced images: A narrative review

OBJECTIVES

To review and evaluate available literature on spectral computed tomography (SCT) bone mineral density (BMD) measurement in adult thoracolumbar vertebrae of unenhanced images compared to quantitative computed tomography (QCT), to understand its current clinical utility.

KEY FINDINGS

Keyword searches in four databases identified four cross-sectional studies which acquired an SCT BMD measurement in thoracolumbar vertebrae and compared this respectively to QCT, which were then critically appraised using the AXIS tool for cross-sectional studies. 862 vertebrae were measured between T10-S1 in 368 patients. Three studies demonstrated a statistically significant correlation between SCT and QCT for the measurement of Hydroxyapatite (HAP) and calcium (r = 0.86-0.96). One study demonstrated a diagnostic accuracy of 96% using a receiver operating curve.

CONCLUSIONS

SCT measurements of HAP and calcium in the lumbar vertebrae are comparable to QCT for patients with no additional pathology present. However, further research is required to evaluate diagnostic accuracy before clinical application.

IMPLICATIONS FOR PRACTICE

SCT BMD measurement has the potential to be developed as a screening tool for osteoporosis within the fracture liaison service (FLS). This could aid in the identification of patients with osteoporosis and address the current treatment gap. Nonetheless, many factors must be considered for this application including staff training, radiation protection and patient engagement with the screening programme.

Real-world effectiveness of osteoporosis screening in older Swedish women (SUPERB)

Older women diagnosed with osteoporosis and referred to their general practitioners (GPs) exhibited significantly higher osteoporosis treatment rates and a reduced fracture risk compared to non-osteoporotic women who were not referred to their GPs.

OBJECTIVE

The objective of this study was to investigate treatment rates and fracture outcomes in older women, from a population-based study, 1) diagnosed with osteoporosis, with subsequent referral to their general practitioner (GP), 2) women without osteoporosis, without referral to their GP.

METHODS

In total, 3028 women, 75-80 years old were included in the SUPERB cohort. At inclusion, 443 women were diagnosed with osteoporosis (bone mineral density (BMD) T-score ≤ -2.5) at the lumbar spine or hip, did not have current or recent osteoporosis treatment, and were referred to their GP for evaluation (referral group). The remaining 2585 women without osteoporosis composed the control group. Sensitivity analysis was performed on subsets of the original groups. Adjusted Cox regression (hazard ratios (HR) and 95 % confidence intervals (CI)) analyses were performed to investigate the risk of incident fractures and the incidence of osteoporosis treatment.

RESULTS

Cox regression models, adjusted for age, sex, body mass index (BMI), smoking, alcohol, glucocorticoid use, previous fracture, parent hip fracture, secondary osteoporosis, rheumatoid arthritis, and BMD at the femoral neck, revealed that the risk of major osteoporotic fracture was significantly lower (HR = 0.81, 95 % CI [0.67-0.99]) in the referral group than in the controls. Similarly, the risk of hip fracture (HR = 0.69, [0.48-0.98]) and any fracture (HR = 0.84, [0.70-1.00]) were lower in the referral group. During follow-up, there was a 5-fold increase (HR = 5.00, [4.39-5.74]) in the prescription of osteoporosis medication in the referral group compared to the control group.

CONCLUSION

Screening older women for osteoporosis and referring those with osteoporosis diagnosis was associated with substantially increased treatment rates and reduced risk of any fracture, MOF, and hip fracture, compared to non-osteoporotic women.

Safety of In-hospital Parenteral Antiosteoporosis Therapy Following a Hip Fracture: A Retrospective Cohort

Purpose

To assess the safety of zoledronic acid (ZOL) and denosumab (Dmab) administered following hip fracture in a hospital setting.

Methods

Patients older than 65 years were treated by a fracture liaison service following hip fracture. Generally, patients who had a glomerular filtration rate (eGFR) > 35 mL/min were treated with ZOL, whereas patients who had previously received bisphosphonates or had a eGFR between 20 and 35 mL/min were treated with Dmab. Adverse events included hypocalcemia (calcium corrected for albumin less than 8.5 mg/day), renal functional impairment (0.5 mg/dL or more increase in serum creatinine) within 30 days of treatment, or a fever (>38 °C) within 48 hours of drug administration.

Results

Two hundred twenty-eight and 134 patients were treated with ZOL and Dmab, respectively. Mean body temperature was elevated following ZOL administration (0.18 °C P < .001) but remained below 38 °C. Hypocalcemia occurred in 18% and 29% of the ZOL and Dmab groups, respectively (P = .009). Renal functional impairment was observed in 9 and 6 patients (4% and 5%) in the ZOL and Dmab groups, respectively (P = .8). Pretreatment calcium above 9.3 mg/dL was associated with a lower risk of posttreatment hypocalcemia (odds ratio 0.30, 95% confidence interval 0.13-0.68, P = .004). While the absolute risk of hypocalcemia was higher in the Dmab group, multivariate analysis did not find that the choice of drug was predictive of hypocalcemia.

Conclusion

In-hospital parenteral osteoporosis treatment was rarely associated with fever or renal function impairment but was associated with hypocalcemia. Posttreatment hypocalcemia risk did not vary significantly between patients receiving ZOL or Dmab.

A causal relationship between bone mineral density and breast cancer risk: a mendelian randomization study based on east Asian population

BACKGROUND

Breast cancer (BC) poses significant burdens on women globally. While past research suggests a potential link between bone mineral density (BMD) and BC risk, findings remain inconsistent. Our study aims to elucidate the causal relationship between BMD and BC in East Asians using bidirectional Mendelian randomization (MR).

METHODS

Genetic association data for bone mineral density T-scores (BMD-T) and Z-scores (BMD-Z) (Sample size = 92,615) and BC from two different sources (Sample size1 = 98,283; Sample size2 = 79,550) were collected from publicly available genome-wide association studies (GWAS). Single-nucleotide polymorphisms (SNPs) associated with BMD-T and BMD-Z as phenotype-related instrumental variables (IVs) were used, with BC as the outcome. As the primary means of causal inference, the inverse variance weighted (IVW) approach was employed. Heterogeneity analysis was conducted using Cochran's Q test, while MR-Egger regression analysis was implemented to assess the pleiotropic effects of the IVs. Sensitivity analyses were performed using methods such as MR-Egger, weighted median, and weighted mode to analyze the robustness and reliability of the results. The MR-PRESSO method and the RadialMR were used to detect and remove outliers. The PhenoScanner V2 website was utilized to exclude confounding factors shared between BMD and BC. Besides, the Bonferroni correction was also used to adjust the significance threshold. Then, the meta-analysis method was applied to combine the MR analysis results from the two BC sources. Finally, a reverse MR analysis was conducted.

RESULTS

The results of the IVW method were consolidated through meta-analysis, revealing a positive correlation between genetically predicted BMD-T ([Formula: see text], [Formula: see text], [Formula: see text]) and BMD-Z ([Formula: see text],[Formula: see text], [Formula: see text]) with increased BC risk. The Cochran's [Formula: see text] test and MR-Egger regression suggested that neither of these causal relationships was affected by heterogeneity or horizontal pleiotropy. The sensitivity analyses supported the IVW results, indicating the robustness of the findings. Reverse MR analysis showed no causal relationship between BC and BMD.

CONCLUSION

Our MR study results provide evidence for the causal relationship between BMD and BC risk in East Asian populations, suggesting that BMD screening is of great significance in detecting and preventing BC.

The influence of modified Qing E Formula on the differential expression of serum exosomal miRNAs in postmenopausal osteoporosis patients

Objective

Although guidelines support the efficacy of Modified Qing' E Formula (MQEF) in treating postmenopausal osteoporosis (PMOP), its underlying mechanisms remain incompletely understood. This retrospective investigation aims to elucidate MQEF's impact on serum exosomal miRNA expression in postmenopausal osteoporosis patients and to explore potential therapeutic mechanisms.

Methods

Following ethical approval and registration, postmenopausal osteoporosis patients aged 50-85 years, meeting the diagnostic criteria were randomly selected and received MQEF decoction supplementary therapy. Serum samples were collected pre- and post-treatment, followed by isolation and sequencing of exosomal miRNAs. Differential miRNAs in serum exosomes were identified, and bioinformatics analysis was conducted to discern the principal exosomal miRNAs involved in MQEF's effects on PMOP and the associated signaling pathways.

Results

Eighteen clinical blood samples were collected. A total of 282,185 target genes were detected across the three groups. 306 miRNAs exhibited altered expression in serum exosomes of PMOP patients, while MQEF intervention resulted in changes in 328 miRNAs. GO enrichment analysis revealed the immune and endocrine systems was pertained. KEGG enrichment analysis indicated associations between PMOP occurrence and MQEF treatment with cytokine interactions, oxidative phosphorylation, and the renin-angiotensin system. Intersectional analysis identified 17 miRNAs, including 2 consistent trends. miR-3188 as a potentially pivotal miRNA implicated in both PMOP occurrence and MQEF treatment.

Conclusion

This study constitutes the first randomized, retrospective clinical exploration confirming that MQEF demonstrates regulatory influence over exosomal miRNA expression in PMOP patients' serum, its impact likely involves modulation of the immune and endocrine systems, as well as the renin-angiotensin system.

The role of short-chain fatty acids in the regulation of osteoporosis: new perspectives from gut microbiota to bone health: A review

Osteoporosis is a systemic skeletal disease characterized by low bone density and microarchitectural deterioration, resulting in increased fracture risk. With an aging population, osteoporosis imposes a heavy burden worldwide. Current pharmacotherapies such as bisphosphonates can reduce fracture risk but have limitations. Emerging research suggests that gut microbiota regulates bone metabolism through multiple mechanisms. Short-chain fatty acids (SCFAs) produced from microbial fermentation of dietary fiber beneficially impact bone health. Preclinical studies indicate that SCFAs such as butyrate and propionate prevent bone loss in osteoporosis models by inhibiting osteoclastogenesis and immune modulation. Early clinical data also suggest that SCFA supplementation may improve bone turnover markers in postmenopausal women. SCFAs likely act via inhibition of osteoclast differentiation, stimulation of osteoblast activity, regulation of T cells, and other pathways. However, optimal dosing, delivery methods, and long-term safety require further investigation. Modulating the gut-bone axis via supplementation, prebiotics/probiotics, diet, and lifestyle interventions represents an innovative therapeutic approach for osteoporosis. Harnessing the interplay between microbiome, metabolism, immunity, and bone may provide new directions for managing osteoporosis in the future.

Osteoporosis treatment: current drugs and future developments

Osteoporosis is a common systemic metabolic disease characterized by a decrease in bone density and bone mass, destruction of bone tissue microstructure, and increased bone fragility leading to fracture susceptibility. Pharmacological treatment of osteoporosis is the focus of current research, and anti-osteoporosis drugs usually play a role in inhibiting bone resorption, promoting bone formation, and having a dual role. However, most of the drugs have the disadvantages of single target and high toxic and side effects. There are many types of traditional Chinese medicines (TCM), from a wide range of sources and mostly plants. Herbal plants have unique advantages in regulating the relationship between osteoporosis and the immune system, acupuncture therapy has significant therapeutic effects in combination with medicine for osteoporosis. The target cells and specific molecular mechanisms of TCM in preventing and treating osteoporosis have not been fully elucidated. At present, there is a lack of comprehensive understanding of the pathological mechanism of the disease. Therefore, a better understanding of the pathological signaling pathways and key molecules involved in the pathogenesis of osteoporosis is crucial for the design of therapeutic targets and drug development. In this paper, we review the development and current status of anti-osteoporosis drugs currently in clinical application and under development to provide relevant basis and reference for drug prevention and treatment of osteoporosis, with the aim of promoting pharmacological research and new drug development.

Mechanistic Insights and Therapeutic Strategies in Osteoporosis: A Comprehensive Review

Osteoporosis, a metabolic bone disorder characterized by decreased bone mass per unit volume, poses a significant global health burden due to its association with heightened fracture risk and adverse impacts on patients' quality of life. This review synthesizes the current understanding of the pathophysiological mechanisms underlying osteoporosis, with a focus on key regulatory pathways governing osteoblast and osteoclast activities. These pathways include RANK/RANKL/OPG, Wingless-int (Wnt)/β-catenin, and Jagged1/Notch1 signaling, alongside the involvement of parathyroid hormone (PTH) signaling, cytokine networks, and kynurenine in bone remodeling. Pharmacotherapeutic interventions targeting these pathways play a pivotal role in osteoporosis management. Anti-resorptive agents, such as bisphosphonates, estrogen replacement therapy/hormone replacement therapy (ERT/HRT), selective estrogen receptor modulators (SERMs), calcitonin, anti-RANKL antibodies, and cathepsin K inhibitors, aim to mitigate bone resorption. Conversely, anabolic agents, including PTH and anti-sclerostin drugs, stimulate bone formation. In addition to pharmacotherapy, nutritional supplementation with calcium, vitamin D, and vitamin K2 holds promise for osteoporosis prevention. However, despite the availability of therapeutic options, a substantial proportion of osteoporotic patients remain untreated, highlighting the need for improved clinical management strategies. This comprehensive review aims to provide clinicians and researchers with a mechanistic understanding of osteoporosis pathogenesis and the therapeutic mechanisms of existing medications. By elucidating these insights, this review seeks to inform evidence-based decision-making and optimize therapeutic outcomes for patients with osteoporosis.

Tumour necrosis factor α regulates the miR-27a-3p-Sfrp1 axis in a mouse model of osteoporosis

Osteoporosis is a metabolic bone disease that involves gradual loss of bone density and mass, thus resulting in increased fragility and risk of fracture. Inflammatory cytokines, such as tumour necrosis factor α (TNF-α), inhibit osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and several microRNAs are implicated in osteoporosis development. This study aimed to explore the correlation between TNF-α treatment and miR-27a-3p expression in BMSC osteogenesis and further understand their roles in osteoporosis. An osteoporosis animal model was established using ovariectomized (OVX) mice. Compared with Sham mice, the OVX mice had a significantly elevated level of serum TNF-α and decreased level of bone miR-27a-3p, and in vitro TNF-α treatment inhibited miR-27a-3p expression in BMSCs. In addition, miR-27a-3p promoted osteogenic differentiation of mouse BMSCs in vitro, as evidenced by alkaline phosphatase staining and Alizarin Red-S staining, as well as enhanced expression of the osteogenic markers Runx2 and Osterix. Subsequent bioinformatics analysis combined with experimental validation identified secreted frizzled-related protein 1 (Sfrp1) as a downstream target of miR-27a-3p. Sfrp1 overexpression significantly inhibited the osteogenic differentiation of BMSCs in vitro and additional TNF-α treatment augmented this inhibition. Moreover, Sfrp1 overexpression abrogated the promotive effect of miR-27a-3p on the osteogenic differentiation of BMSCs. Furthermore, the miR-27a-3p-Sfrp1 axis was found to exert its regulatory function in BMSC osteogenic differentiation via regulating Wnt3a-β-catenin signalling. In summary, this study revealed that TNF-α regulated a novel miR-27a-3p-Sfrp1 axis in osteogenic differentiation of BMSCs. The data provide new insights into the development of novel therapeutic strategies for osteoporosis.

Clinical challenges and considerations in pharmacotherapy of osteoporosis due to menopause

INTRODUCTION

Osteoporosis is a chronic systemic skeletal disorder characterized by compromised bone strength and an increased risk of fracture, with a high prevalence worldwide. It is associated with a negative quality of life and an increased morbidity and mortality. Postmenopausal women are more prone to develop osteoporosis, and many of them will suffer at least one fragility fracture along their lifetime.

AREAS COVERED

This review starts by summarizing the pathogenesis of postmenopausal osteoporosis (PMO), with focus on the estrogen deficiency-associated bone loss. It continues with the current PMO diagnostic and fracture risk prediction tools, and it finally addresses management of PMO. All the efficacy and safety profiles of the current and future osteoporosis medications are reviewed. Furthermore, strategies to optimize the long-term disease management are discussed. For this review, only publications in English language were selected. References were extracted from PubMed, Embase, and Medline.

EXPERT OPINION

PMO disease management is far from being ideal. Educational and communication programs with the goal of improving disease knowledge and awareness, as well as reducing the health-care gap, should be implemented. In addition, most effective sequential prevention and treatment strategies should be initiated from the early menopause.

Targeted delivery of anti-osteoporosis therapy: Bisphosphonate-modified nanosystems and composites

Osteoporosis (OP) constitutes a significant health concern that profoundly affects individuals' quality of life. Bisphosphonates, conventional pharmaceuticals widely employed in OP treatment, encounter limitations related to inadequate drug targeting and a short effective duration, thereby compromising their clinical efficacy. The burgeoning field of nanotechnology has witnessed the development and application of diverse functional nanosystems designed for OP treatment. Owing to the bone tissue affinity of bisphosphonates, these nanosystems are modified to address shortcomings associated with traditional drug delivery. In this review, we explore the potential of bisphosphonate-modified nanosystems as a promising strategy for addressing osteoporotic conditions. With functional modification, these nanosystems exhibit a targeted and reversible effect on osteoporotic remodeling, presenting a promising solution to enhance precision in drug delivery. The synthesis methods, physicochemical properties, and in vitro/in vivo performance of bisphosphonate-modified nanosystems are comprehensively examined in this review. Through a thorough analysis of recent advances and accomplishments in this field, we aim to provide insights into the potential applications and future directions of bisphosphonate-modified nanosystems for targeted and reversible osteoporotic remodeling.

The significance of recent fracture location for imminent risk of hip and vertebral fractures-a nationwide cohort study on older adults in Sweden

The role of recent fracture site in predicting the most detrimental subsequent fractures, hip and vertebral, is unclear. This study found that most recent fracture sites were associated with an increased risk of both hip and vertebral fracture, a finding that may impact the design of secondary prevention programs.

BACKGROUND

Hip and vertebral fractures are the most serious in terms of associated morbidity, mortality, and societal costs. There is limited evidence as to which fracture types are associated with the highest risk for subsequent hip and vertebral fractures. This study aims to explore the dependency of imminent hip and vertebral fracture risk on the site of the recent index fracture.

METHODS

Conducted as a nationwide retrospective cohort study, we utilized Swedish national registers to assess the risk of hip and vertebral fractures based on the site of the recent (≤ 2 years) index fracture and an old (> 2 years) prevalent fracture. This risk was compared to that observed in individuals without any prevalent fractures. This study encompassed all Swedes aged 50 years and older between 2007 and 2010. Patients with a recent fracture were categorized into specific groups based on the type of their previous fracture and were followed until December 2017, with censoring for death and migration. The study assessed the risk of hip and vertebral fractures during the follow-up period.

RESULTS

The study included a total of 3,423,320 individuals, comprising 145,780 with a recent fracture, 293,051 with an old fracture, and 2,984,489 without a previous fracture. The median follow-up times for the three groups were 7.6 years (IQR 4.0-9.1), 7.9 years (5.8-9.2), and 8.5 years (7.4-9.7), respectively. Patients with a recent fracture at almost all sites exhibited a significantly increased risk of hip fracture and an elevated risk of vertebral fracture compared to controls. Patients with recent fractures had an increased risk of subsequent hip and vertebral fractures, regardless of the index fracture site. These results strengthen the notion that all patients with a recent fracture, regardless of fracture site, should be included in secondary prevention programs, to improve the prevention of the clinically most serious fractures.

Immunomodulatory nanomedicine for osteoporosis: Current practices and emerging prospects

Osteoporosis results from the disruption of the balance between bone resorption and bone formation. However, classical anti-osteoporosis drugs exhibit several limitations in clinical applications, such as multiple adverse reactions and poor therapeutic effects. Therefore, there is an urgent need for alternative treatment strategies. With the evolution of immunomodulatory nanomedicine, a variety of nanomaterials have been designed for anti-osteoporosis treatment, offering prospects of minimal adverse reactions, enhanced bone induction, and high osteogenic activity. This review initially provides a brief overview of the fundamental principles of bone reconstruction, current osteogenic clinical methods in osteoporosis treatment, and the significance of osteogenic-angiogenic coupling, laying the groundwork for understanding the pathophysiology and therapeutics of osteoporosis. Subsequently, the article emphasizes the relationship between bone immunity and osteogenesis-angiogenesis coupling and provides a detailed analysis of the application of immunomodulatory nanomedicines in the treatment of osteoporosis, including various types of nanomaterials and their integration with carrier biomaterials. Importantly, we discuss the potential of some emerging strategies in immunomodulatory nanomedicine for osteoporosis treatment. This review introduces the innovative applications of immunomodulatory nanomedicine in the treatment of osteoporosis, aiming to serve as a reference for the application of immunomodulatory nanomedicine strategies in osteoporosis treatment. STATEMENT OF SIGNIFICANCE: Osteoporosis, as one of the most prevalent skeletal disorders, poses a significant threat to public health. To date, conventional anti-osteoporosis strategies have been limited in efficacy and plagued with numerous side effects. Fortunately, with the advancement of research in osteoimmunology and nanomedicine, strategies integrating these two fields show great promise in combating osteoporosis. Nanomedicine with immunomodulatory properties exhibits enhanced efficiency, prolonged effectiveness, and increased safety. However, as of now, there exists no comprehensive review amalgamating immunomodulation with nanomedicine to delineate the progress of immunomodulatory nanomedicine in osteoporosis treatment, as well as the future direction of this strategy.

External validation of a deep learning model for predicting bone mineral density on chest radiographs

We developed a new model for predicting bone mineral density on chest radiographs and externally validated it using images captured at facilities other than the development environment. The model performed well and showed potential for clinical use.

PURPOSE

In this study, we performed external validation (EV) of a developed deep learning model for predicting bone mineral density (BMD) of femoral neck on chest radiographs to verify the usefulness of this model in clinical practice.

METHODS

This study included patients who visited any of the collaborating facilities from 2010 to 2020 and underwent chest radiography and dual-energy X-ray absorptiometry (DXA) at the femoral neck in the year before and after their visit. A total of 50,114 chest radiographs were obtained, and BMD was measured using DXA. We developed the model with 47,150 images from 17 facilities and performed EV with 2914 images from three other facilities (EV dataset). We trained the deep learning model via ensemble learning based on chest radiographs, age, and sex to predict BMD using regression. The outcomes were the correlation of the predicted BMD and measured BMD with diagnoses of osteoporosis and osteopenia using the T-score estimated from the predicted BMD.

RESULTS

The mean BMD was 0.64±0.14 g/cm2 in the EV dataset. The BMD predicted by the model averaged 0.61±0.08 g/cm2, with a correlation coefficient of 0.68 (p<0.01) when compared with the BMD measured using DXA. The accuracy, sensitivity, and specificity of the model were 79.0%, 96.6%, and 34.1% for T-score < -1 and 79.7%, 77.1%, and 80.4% for T-score ≤ -2.5, respectively.

CONCLUSION

Our model, which was externally validated using data obtained at facilities other than the development environment, predicted BMD of femoral neck on chest radiographs. The model performed well and showed potential for clinical use.

Enhancing osteoporosis treatment with engineered mesenchymal stem cell-derived extracellular vesicles: mechanisms and advances

As societal aging intensifies, the incidence of osteoporosis (OP) continually rises. OP is a skeletal disorder characterized by reduced bone mass, deteriorated bone tissue microstructure, and consequently increased bone fragility and fracture susceptibility, typically evaluated using bone mineral density (BMD) and T-score. Not only does OP diminish patients' quality of life, but it also imposes a substantial economic burden on society. Conventional pharmacological treatments yield limited efficacy and severe adverse reactions. In contemporary academic discourse, mesenchymal stem cells (MSCs) derived extracellular vesicles (EVs) have surfaced as auspicious novel therapeutic modalities for OP. EVs can convey information through the cargo they carry and have been demonstrated to be a crucial medium for intercellular communication, playing a significant role in maintaining the homeostasis of the bone microenvironment. Furthermore, various research findings provide evidence that engineered strategies can enhance the therapeutic effects of EVs in OP treatment. While numerous reviews have explored the progress and potential of EVs in treating degenerative bone diseases, research on using EVs to address OP remains in the early stages of basic experimentation. This paper reviews advancements in utilizing MSCs and their derived EVs for OP treatment. It systematically examines the most extensively researched MSC-derived EVs for treating OP, delving not only into the molecular mechanisms of EV-based OP therapy but also conducting a comparative analysis of the strengths and limitations of EVs sourced from various cell origins. Additionally, the paper emphasizes the technical and engineering strategies necessary for leveraging EVs in OP treatment, offering insights and recommendations for future research endeavors.

Mitochondrial dysfunction and therapeutic perspectives in osteoporosis

Osteoporosis (OP) is a systemic skeletal disorder characterized by reduced bone mass and structural deterioration of bone tissue, resulting in heightened vulnerability to fractures due to increased bone fragility. This condition primarily arises from an imbalance between the processes of bone resorption and formation. Mitochondrial dysfunction has been reported to potentially constitute one of the most crucial mechanisms influencing the pathogenesis of osteoporosis. In essence, mitochondria play a crucial role in maintaining the delicate equilibrium between bone formation and resorption, thereby ensuring optimal skeletal health. Nevertheless, disruption of this delicate balance can arise as a consequence of mitochondrial dysfunction. In dysfunctional mitochondria, the mitochondrial electron transport chain (ETC) becomes uncoupled, resulting in reduced ATP synthesis and increased generation of reactive oxygen species (ROS). Reinforcement of mitochondrial dysfunction is further exacerbated by the accumulation of aberrant mitochondria. In this review, we investigated and analyzed the correlation between mitochondrial dysfunction, encompassing mitochondrial DNA (mtDNA) alterations, oxidative phosphorylation (OXPHOS) impairment, mitophagy dysregulation, defects in mitochondrial biogenesis and dynamics, as well as excessive ROS accumulation, with regards to OP (Figure 1). Furthermore, we explore prospective strategies currently available for modulating mitochondria to ameliorate osteoporosis. Undoubtedly, certain therapeutic strategies still require further investigation to ensure their safety and efficacy as clinical treatments. However, from a mitochondrial perspective, the potential for establishing effective and safe therapeutic approaches for osteoporosis appears promising.

Patient Perception on Osteoporosis in Korean Female Patients with Osteoporosis

BACKGROUND

Patient perception is a key element in improving compliance with medications for osteoporosis. This study evaluated the awareness, perception, sources of information, and knowledge of osteoporosis among Korean women with osteoporosis.

METHODS

A questionnaire survey was conducted from July 22, 2021 to 13 August 2021. Patients who were followed up in endocrinology (Endo), orthopedic surgery (OS), and gynecology (GY) were recruited (N=40, 40, and 20 in each group). Patients were allocated according to their age, as follows: 15, 15, and 10 patients in their 60s, 70s, and 80s for Endo and OS, and 10 and 10 patients in their 60s and 70s for GY. The questionnaire was composed of the following topics: patient journey to the hospital, drug-related issues, communication with medical doctors, patient knowledge, and sources of information about osteoporosis.

RESULTS

The results of medical check-ups were the most common reason for patient visits to the hospital for an initial diagnosis of osteoporosis (61%). A knowledge gap regarding mortality, refracture, and drug-induced osteoporosis was observed. Doctors were the most preferred and trustful source of information, while health-related TV shows were the second most common source of information. Patients with OS reported lower perceived severity and higher drug discontinuation, along with a higher proportion of fractures, as the initial reasons for hospital visits for osteoporosis.

CONCLUSIONS

Variations in perceptions according to the issue and group were identified. These should be considered during patient consultations to improve compliance with osteoporosis treatment.

Physicians' awareness of medication-related osteonecrosis of the jaw in patients with osteoporosis

A serious adverse effect of antiresorptive drugs, which are widely used to treat osteoporosis, is medication-related osteonecrosis of the jaw (MRONJ). Physicians can reduce the risk of MRONJ by educating patients and emphasizing the importance of good oral health. However, limited information is available regarding physicians' awareness and clinical practices associated with MRONJ. Hence, this study aimed to examine physicians' awareness related to MRONJ and associated clinical practices. This study was a cross-sectional study conducted from December 2022 to February 2023. An online self-administered questionnaire was sent to physicians in Thailand who prescribed antiresorptive drugs for osteoporosis. Most respondents agreed that antiresorptive drugs might cause MRONJ (92.3%), poor oral health increased the risk of MRONJ (84%), and MRONJ is an important consideration in patients with osteoporosis (85%). Of the respondents, 48.1% and 15.5% always referred patients to dentists before and during antiresorptive therapy, respectively. Approximately 60% of physicians informed patients of the MRONJ risk before prescribing antiresorptive drugs, and 30% inquired about patients' oral symptoms at the follow-up visit. Overall, 44% of physicians advised patients to receive oral health care; the most common reason for not advising this was that respondents did not consider themselves to be adequately knowledgeable to detect oral health problems. These findings indicate that while most physicians who prescribed antiresorptive drugs for osteoporosis were aware of and considered MRONJ in their practice, several took insufficient action to prevent it. This highlights the need to emphasize clinical practice guidelines and collaboration between physicians and dentists.

Bone-Targeting Peptide and RNF146 Modified Apoptotic Extracellular Vesicles Alleviate Osteoporosis

Background

Osteoporosis is a highly prevalent disease that causes fractures and loss of motor function. Current drugs targeted for osteoporosis often have inevitable side effects. Bone marrow mesenchymal stem cell (BMSCs)-derived apoptotic extracellular vesicles (ApoEVs) are nanoscale extracellular vesicles, which has been shown to promote bone regeneration with low immunogenicity and high biological compatibility. However, natural ApoEVs cannot inherently target bones, and are often eliminated by macrophages in the liver and spleen. Thus, our study aimed to reconstruct ApoEVs to enhance their bone-targeting capabilities and bone-promoting function and to provide a new method for osteoporosis treatment.

Methods

We conjugated a bone-targeting peptide, (Asp-Ser-Ser)6 ((DSS)6), onto the surface of ApoEVs using standard carbodiimide chemistry with DSPE-PEG-COOH serving as the linker. The bone-targeting ability of (DSS)6-ApoEVs was determined using an in vivo imaging system and confocal laser scanning microscopy (CLSM). We then loaded ubiquitin ligase RING finger protein146 (RNF146) into BMSCs via adenovirus transduction to obtain functional ApoEVs. The bone-promoting abilities of (DSS)6-ApoEVs and (DSS)6-ApoEVsRNF146 were measured in vitro and in vivo.

Results

Our study successfully synthesized bone-targeting and gained functional (DSS)6-ApoEVsRNF146 and found that engineered ApoEVs could promote osteogenesis in vitro and exert significant bone-targeting and osteogenesis-promoting effects to alleviate osteoporosis in a mouse model.

Conclusion

To promote the bone-targeting ability of natural ApoEVs, we successfully synthesized engineered ApoEVs, (DSS)6-ApoEVsRNF146 and found that they could significantly promote osteogenesis and alleviate osteoporosis compared with natural ApoEVs, which holds great promise for the treatment of osteoporosis.

New flavan trimer from Daemonorops draco as osteoclastogenesis inhibitor

Dragon's blood is a red resin obtained from different plants and is considered highly efficacious and used in medicine owing its wound healing function. Two new compounds (7 and 8) were isolated from the dragon's blood of Daemonorops draco fruits, along with eight known compounds (1-6, 9, and 10). Their structures, including their absolute configurations, were elucidated by nuclear magnetic resonance (NMR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electronic circular dichroism (ECD) analysis. According to the spectroscopic data, 8 was determined to be a quinone methide derivative of flavan and 7 was deduced to be a flavan trimer. All compounds were evaluated for their anti-osteoclastogenesis activity, compound 1 and 7 exhibited anti-osteoclastogenesis activity with IC50 values of 31.3 and 36.8 μM, respectively.

Establish and validate the reliability of predictive models in bone mineral density by deep learning as examination tool for women

While FRAX with BMD could be more precise in estimating the fracture risk, DL-based models were validated to slightly reduce the number of under- and over-treated patients when no BMD measurements were available. The validated models could be used to screen for patients at a high risk of fracture and osteoporosis.

PURPOSE

Fracture risk assessment tool (FRAX) is useful in classifying the fracture risk level, and precise prediction can be achieved by estimating both clinical risk factors and bone mineral density (BMD) using dual X-ray absorptiometry (DXA). However, DXA is not frequently feasible because of its cost and accessibility. This study aimed to establish the reliability of deep learning (DL)-based alternative tools for screening patients at a high risk of fracture and osteoporosis.

METHODS

Participants were enrolled from the National Bone Health Screening Project of Taiwan in this cross-sectional study. First, DL-based models were built to predict the lowest T-score value in either the lumbar spine, total hip, or femoral neck and their respective BMD values. The Bland-Altman analysis was used to compare the agreement between the models and DXA. Second, the predictive model to classify patients with a high fracture risk was built according to the estimated BMD from the first step and the FRAX score without BMD. The performance of the model was compared with the classification based on FRAX with BMD.

RESULTS

Approximately 10,827 women (mean age, 65.4 ± 9.4 years) were enrolled. In the prediction of the lumbar spine BMD, total hip BMD, femoral neck BMD, and lowest T-score, the root-mean-square error (RMSE) was 0.099, 0.089, 0.076, and 0.68, respectively. The Bland-Altman analysis revealed a nonsignificant difference between the predictive models and DXA. The FRAX score with femoral neck BMD for major osteoporotic fracture risk was 9.7% ± 6.7%, whereas the risk for hip fracture was 3.3% ± 4.6%. Comparison between the classification of FRAX with and without BMD revealed the accuracy rate, positive predictive value (PPV), and negative predictive value (NPV) of 78.8%, 64.6%, and 89.9%, respectively. The area under the receiver operating characteristic curve (AUROC), accuracy rate, PPV, and NPV of the classification model were 0.913 (95% confidence interval: 0.904-0.922), 83.5%, 71.2%, and 92.2%, respectively.

CONCLUSION

While FRAX with BMD could be more precise in estimating the fracture risk, DL-based models were validated to slightly reduce the number of under- and over-treated patients when no BMD measurements were available. The validated models could be used to screen for patients at a high risk of fracture and osteoporosis.

The unique role of bone marrow adipose tissue in ovariectomy-induced bone loss in mice

BACKGROUND

Accumulation of bone marrow adipose tissue (BMAT) is always seen in osteoporosis induced by estrogen deficiency. Herein, we aimed to investigate the mechanisms and consequences of this phenomenon by establishing a mouse model of osteoporosis caused by ovariectomy (OVX)-mimicked estrogen deficiency.

METHODS

Micro-CT, osmium tetroxide staining, and histological analyses were performed to examine the changes in bone microstructure, BMAT and white adipose tissue (WAT) in OVX mice compared to sham mice. The osteogenesis and adipogenesis of primary bone marrow stromal cells (BMSCs) isolated from sham and OVX mice were compared in vitro. The molecular phenotypes of BMAT and WAT were determined and compared by quantitative PCR (qPCR). Bone marrow adipocyte-conditioned medium (BMA CM) was prepared from sham or OVX mice for coculture assays, and BMSCs or bone marrow monocytes/macrophages (BMMs) were isolated and subjected to osteoblast and osteoclast differentiation, respectively. Cell staining and qPCR were used to assess the effects of BMAT on bone metabolism.

RESULTS

OVX-induced estrogen deficiency induced reductions in both cortical and trabecular bone mass along with an expansion of BMAT volume. At the cellular level, loss of estrogen inhibited BMSC osteogenesis and promoted BMSC adipogenesis, whereas addition of estradiol exerted the opposite effects. In response to estrogen deficiency, despite the common proinflammatory molecular phenotype observed in both fat depots, BMAT, unlike WAT, unexpectedly exhibited an increase in adipocyte differentiation and lipolytic activity as well as the maintenance of insulin sensitivity. Importantly, BMAT, but not WAT, presented increased mRNA levels of both BMP receptor inhibitors (Grem1, Chrdl1) and Rankl following OVX. In addition, treatment with BMA CM, especially from OVX mice, suppressed the osteoblast differentiation of BMSCs while favoring the osteoclast differentiation of BMMs.

CONCLUSION

Our study illustrates that OVX-induced estrogen deficiency results in bone loss and BMAT expansion by triggering imbalance between the osteogenesis and adipogenesis of BMSCs. Furthermore, expanded BMAT, unlike typical WAT, may negatively regulate bone homeostasis through paracrine inhibition of osteoblast-mediated bone formation and promotion of osteoclast-mediated bone resorption.

Clinical frontiers of metabolic bone disorders: a comprehensive review

Metabolic bone disease (MBD)encompasses various conditions that adversely impact bone health, such as osteoporosis, primary hyperparathyroidism, osteomalacia, and fluorosis disease. Effectively managing these disorders requires early detection and a focus on maintaining healthy nutritional habits. Dietary adjustments serve as a cornerstone, but supplementation of essential minerals like calcium, phosphate, and vitamin D is often necessary to support bone reabsorption and regeneration, and reduce fracture risk. Despite the effectiveness of these measures in many cases, hereditary bone diseases pose distinctive challenges due to genetic factors. Emerging technologies that provide higher-resolution insights into bone architecture and quality are now complementing traditional diagnostic tools like dual-energy X-ray absorptiometry (DXA). Moreover, the therapeutic landscape has transformed with the introduction of newer agents that not only halt bone loss but also stimulate bone formation. These agents promise better outcomes with reduced side effects, catering to a wider patient population. However, the management of MBDs remains multifaceted, necessitating individualized approaches based on the patient’s clinical profile. As the global prevalence of MBDs, especially osteoporosis, continues to soar, it becomes imperative for clinicians to stay abreast with the evolving paradigms. This review serves as a bridge between historical knowledge and recent discoveries, offering a holistic perspective on the challenges and opportunities in the domain of MBDs.

Periostin-targeted SDSSD peptide decorated calcium phosphate nanocomposites incorporation with simvastatin for osteoporosis treatment

The limited options of anabolic drugs restrict their application potential in osteoporosis treatment, despite their theoretical superiority in therapeutic efficacy over antiresorptive drugs. As a prevailing strategy, nano-delivery systems could offer a wider choice of anabolic drugs. In this study, calcium phosphate nanocomposites incorporated with simvastatin (Sim) with periostin-targeting ability were designed and prepared for osteoporosis treatment. Carboxymethyl dextran (CMD) as an anionic and hydrophilic dextran derivative was used to stabilize CaP. In addition, periosteum-targeted peptide (SDSSD) was further grafted on CMD to achieve the bone targeting function. In a one-step coordination assembly strategy, hydrophobic anabolic agent Sim and SDSSD-CMD graft (SDSSD-CMD) were incorporated into the CaP nanoparticles forming SDSSD@CaP/Sim nanocomposites. The resulting SDSSD@CaP/Sim possesses uniform size, great short-term stability and excellent biocompatibility. Moreover, SDSSD@CaP/Sim exhibited a reduced release rate of Sim and showed slow-release behaviour. As anticipated, the nanocomposites exhibited bone bonding capacity in both cellular and animal studies. Besides, SDSSD@CaP/Sim achieved obviously enhanced osteoporosis treatment effect compared to direct injection of Simin vivo. Therefore, our findings highlight the potential of SDSSD-incorporated and CaP-based nanocomposites as a viable strategy to enhance the therapeutic efficacy of anabolic drugs for osteoporosis treatment.

Bone mineral density estimation from a plain X-ray image by learning decomposition into projections of bone-segmented computed tomography

Osteoporosis is a prevalent bone disease that causes fractures in fragile bones, leading to a decline in daily living activities. Dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) are highly accurate for diagnosing osteoporosis; however, these modalities require special equipment and scan protocols. To frequently monitor bone health, low-cost, low-dose, and ubiquitously available diagnostic methods are highly anticipated. In this study, we aim to perform bone mineral density (BMD) estimation from a plain X-ray image for opportunistic screening, which is potentially useful for early diagnosis. Existing methods have used multi-stage approaches consisting of extraction of the region of interest and simple regression to estimate BMD, which require a large amount of training data. Therefore, we propose an efficient method that learns decomposition into projections of bone-segmented QCT for BMD estimation under limited datasets. The proposed method achieved high accuracy in BMD estimation, where Pearson correlation coefficients of 0.880 and 0.920 were observed for DXA-measured BMD and QCT-measured BMD estimation tasks, respectively, and the root mean square of the coefficient of variation values were 3.27 to 3.79% for four measurements with different poses. Furthermore, we conducted extensive validation experiments, including multi-pose, uncalibrated-CT, and compression experiments toward actual application in routine clinical practice.

Hemoglobin Levels Improve Fracture Risk Prediction in Addition to FRAX Clinical Risk Factors and Bone Mineral Density

CONTEXT

Anemia and decreasing levels of hemoglobin (Hb) have previously been linked to increased fracture risk, but the added value to FRAX, the most utilized fracture prediction tool worldwide, is unknown.

OBJECTIVE

To investigate the association between anemia, Hb levels, bone microstructure, and risk of incident fracture and to evaluate whether Hb levels improve fracture risk prediction in addition to FRAX clinical risk factors (CRFs).

METHODS

A total of 2778 community-dwelling women, aged 75-80 years, and part of a prospective population-based cohort study in Sweden were included. At baseline, information on anthropometrics, CRFs, and falls was gathered, blood samples were collected, and skeletal characteristics were investigated using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography. At the end of follow-up, incident fractures were retrieved from a regional x-ray archive.

RESULTS

The median follow-up time was 6.4 years. Low Hb was associated with worse total hip and femoral neck bone mineral density (BMD), and lower tibia cortical and total volumetric BMD, and anemia was associated with increased risk of major osteoporotic fracture (MOF; hazard ratio 2.04; 95% CI 1.58-2.64). Similar results were obtained for hip fracture and any fracture, also when adjusting for CRFs. The ratio between 10-year fracture probabilities of MOF assessed in models with Hb levels included and not included ranged from 1.2 to 0.7 at the 10th and 90th percentile of Hb, respectively.

CONCLUSION

Anemia and decreasing levels of Hb are associated with lower cortical BMD and incident fracture in older women. Considering Hb levels may improve the clinical evaluation of patients with osteoporosis and the assessment of fracture risk.

An atlas of genetic determinants of forearm fracture

Osteoporotic fracture is among the most common and costly of diseases. While reasonably heritable, its genetic determinants have remained elusive. Forearm fractures are the most common clinically recognized osteoporotic fractures with a relatively high heritability. To establish an atlas of the genetic determinants of forearm fractures, we performed genome-wide association analyses including 100,026 forearm fracture cases. We identified 43 loci, including 26 new fracture loci. Although most fracture loci associated with bone mineral density, we also identified loci that primarily regulate bone quality parameters. Functional studies of one such locus, at TAC4, revealed that Tac4-/- mice have reduced mechanical bone strength. The strongest forearm fracture signal, at WNT16, displayed remarkable bone-site-specificity with no association with hip fractures. Tall stature and low body mass index were identified as new causal risk factors for fractures. The insights from this atlas may improve fracture prediction and enable therapeutic development to prevent fractures.

Advances in Bioresorbable Triboelectric Nanogenerators

With the growing demand for next-generation health care, the integration of electronic components into implantable medical devices (IMDs) has become a vital factor in achieving sophisticated healthcare functionalities such as electrophysiological monitoring and electroceuticals worldwide. However, these devices confront technological challenges concerning a noninvasive power supply and biosafe device removal. Addressing these challenges is crucial to ensure continuous operation and patient comfort and minimize the physical and economic burden on the patient and the healthcare system. This Review highlights the promising capabilities of bioresorbable triboelectric nanogenerators (B-TENGs) as temporary self-clearing power sources and self-powered IMDs. First, we present an overview of and progress in bioresorbable triboelectric energy harvesting devices, focusing on their working principles, materials development, and biodegradation mechanisms. Next, we examine the current state of on-demand transient implants and their biomedical applications. Finally, we address the current challenges and future perspectives of B-TENGs, aimed at expanding their technological scope and developing innovative solutions. This Review discusses advancements in materials science, chemistry, and microfabrication that can advance the scope of energy solutions available for IMDs. These innovations can potentially change the current health paradigm, contribute to enhanced longevity, and reshape the healthcare landscape soon.