ACOG Committee on Clinical Practice Guidelines–Gynecology. Management of Postmenopausal Osteoporosis: ACOG Clinical Practice Guideline No. 2

Association between hypertension and osteoporosis: a population-based cross-sectional study

BACKGROUND

Current evidence suggests that metabolic dysregulation is inextricably linked to both hypertension and osteoporosis, but the correlation between hypertension and osteoporosis is still unclear. Therefore, in this study, we explored the correlation between hypertension and osteoporosis.

METHODS

A total of 37,807 participants from the National Health and Nutrition Examination Survey (1999-2010, 2013-2014, 2017-2018) were enrolled in this population-based cross-sectional study. Hypertension was considered an exposure factor and osteoporosis was considered an outcome factor. Logistic regression and subgroup analysis were used to assess the association between hypertension and osteoporosis.

RESULTS

A total of 2,523 participants, with a mean age of 68.65 ± 12.21 years, suffered from osteoporosis, and 86.2% were female. Participants with osteoporosis had a greater prevalence of hypertension than participants without osteoporosis (p < 0.001). Participants with hypertension also had a greater prevalence of osteoporosis than participants without hypertension (p < 0.001). Univariate logistic regression analysis indicated that hypertension was associated with osteoporosis (OR: 2.693, 95% CI: 2.480-2.924, p < 0.001). Multivariate logistic regression analysis with a fully adjusted model indicated that hypertension was strongly associated with osteoporosis (OR: 1.183, 95% CI: 1.055-1.327, p = 0.004). Subgroup analysis revealed that the associations between hypertension and osteoporosis were significant in the younger than 60 years, male sex, diabetes subgroup and hypercholesterolemia subgroup (p < 0.05).

CONCLUSION

Hypertension was independently associated with osteoporosis in the general population.

Nutrition Assessment and Management in Celiac Disease

Celiac disease (CeD) is the most common immune condition affecting the gastrointestinal tract; it is triggered by gluten and the only available treatment is a strict gluten-free diet (GFD). Therefore, for patients with CeD, adopting a GFD is not a lifestyle choice. The major problem is that a GFD is restrictive and, like all restrictive diets, it has the potential for adverse nutritional outcomes, especially if adopted for a long term. It is well known that GFD can be nutritionally inadequate and is frequently associated with vitamin and mineral deficiencies; it is also associated with excessive sugar and fat intake, particularly when gluten-free substitutes are consumed. Consequently, people with CeD are affected by higher rates of overweight and obesity and metabolic complications, such as fatty liver and cardiovascular disease. Therefore, assessment of nutritional status and diet quality at diagnosis and while on a long-term GFD is key in the management of CeD. This narrative review addresses nutritional considerations in CeD and management of common challenges associated with a GFD.

Associations of healthy eating index-2015 with osteoporosis and low bone mass density in postmenopausal women: a population-based study from NHANES 2007-2018

Purpose

The current study aimed to explore the associations of diet quality assessed by healthy eating index-2015 (HEI-2015) with risks of osteoporosis and low bone mineral density (BMD) among American postmenopausal women aged 50 years and older.

Methods

Postmenopausal women aged 50 years and older in the National Health and Nutrition Examination Survey from 2007 through 2018 were included in the final sample. Analysis of variance and Rao-Scott adjusted chi-square tests were used to compare the characteristics across tertiles of HEI-2015. Univariate and multivariate weighted logistic regression models were employed to explore the associations of HEI-2015 tertiles and continuous HEI-2015 with the risks of osteoporosis and low BMD. Nonlinear dose-response associations were evaluated using weighted restricted cubic spline analyses, and the contributions of various HEI-2015 components were assessed using weighted quantile sum regression models.

Results

The final sample included 3,421 postmenopausal women aged 50 years and older representative for approximately 28.38 million non-institutionalized U.S. postmenopausal women. Osteoporosis prevalence decreased with HEI-2015 tertiles while the prevalence of low BMD showed no significant decrease. Compared with postmenopausal women in the first tertile of HEI-2015, those with the second (OR: 0.57, 95%CI: 0.38-0.84) and third (OR: 0.48, 95%CI: 0.29-0.78) HEI-2015 tertiles were associated with reduced osteoporosis risk after multivariate adjustments, but no significant association of HEI-2015 with the risk of BMD was identified. Furthermore, similar effects were confirmed in the sensitivity analyses and subgroup analyses and interaction effects. Moreover, significant nonlinear associations were observed between HEI-2015 with osteoporosis risk, and total vegetables, refined grains and greens and beans demonstrated the strongest protective effect among HEI-2015 components against osteoporosis.

Conclusions

This study strongly suggests the significant negative associations of HEI-2015 with osteoporosis risk in American postmenopausal women. These findings highlight the importance of adherence to the dietary guidelines for Americans in reducing the risk of osteoporosis.

Eupatilin ameliorates postmenopausal osteoporosis via elevating microRNA-211-5p and repressing JAK2/STAT3 pathway

Postmenopausal osteoporosis (PMOP) poses a significant threat to women's health worldwide. Eupatilin is a key bioactive component of the Chinese herbal medicine Artemisia asiatica Nakai. Recent research reports have proved the inhibitory function of Eupatilin in many diseases. MicroRNAs (miRNAs) are 21-23 nucleotide-long, single-stranded, noncoding RNA molecules generated endogenously, and many studies have indicated that miRNAs are involved in the development of osteoporosis. This study explored the role and potential mechanism of Eupatilin underlying PMOP. First, rats were given intragastric administration of Eupatilin every day and subcutaneous injections of oligonucleotides or plasmids that interfered with miR-211-5p or janus kinase 2 (JAK2) once a week. After 4 weeks, the PMOP rat model was established. Then, serum alkaline phosphatase, calcium, and phosphorus levels, as well as femur bone mineral density and biomechanical parameters, were detected. Hematoxylin-eosin staining and Masson staining were applied for detecting the pathological condition of femur, and immunohistochemical staining was for detecting osteocalcin. MC3T3-E1 cells were transfected with plasmid vectors interfering with miR-211-5p or JAK2; and cell viability, lactate dehydrogenase cytotoxicity, and cell mineralization were subsequently examined. The relationship between miR-211-5p and JAK2/signal transducer and activator of transcription 3 (STAT3) pathway was analyzed. The targeting relation between miR-211-5p and JAK2 was also verified. The experimental results revealed that Eupatilin improved the pathological conditions of PMOP rats by promoting the proliferation and mineralization of osteoblasts. MiR-211-5p was down-regulated and JAK2/STAT3 was upregulated in PMOP rats. Upregulation of miR-211-5p further improved the pathological conditions of PMOP rats based on Eupatilin treatment. MiR-211-5p inhibited the JAK2/STAT3 pathway. JAK2 offset the effects of elevated miR-211-5p on PMOP rats. Overall, Eupatilin attenuates PMOP through elevating miR-211-5p and repressing JAK2/STAT3 pathway, which suggests the utility of Eupatilin as a potential drug for POMP treatment.

Trajectories of oral bisphosphonate use after hip fractures: a population-based cohort study

Bisphosphonates prevent future hip fractures. However, we found that one in six patients with hip fractures had a delay in bisphosphonate initiation and another one-sixth discontinued treatment within 12 months after discharge. Our results highlight the need to address hesitancy in treatment initiation and continuous monitoring.

PURPOSE

Suboptimal antiresorptive use is not well understood. This study investigated trajectories of oral bisphosphonate use following first hip fractures and factors associated with different adherence and persistence trajectories.

METHODS

We conducted a retrospective study of all patients aged ≥ 50 years dispensed two or more bisphosphonate prescriptions following first hip fracture in Victoria, Australia, from 2012 to 2017. Twelve-month trajectories of bisphosphonate use were categorized using group-based trajectory modeling. Factors associated with different trajectories compared to the persistent adherence trajectory were assessed using multivariate multinomial logistic regression.

RESULTS

We identified four patterns of oral bisphosphonate use in 1811 patients: persistent adherence (66%); delayed dispensing (17%); early discontinuation (9%); and late discontinuation (9%). Pre-admission bisphosphonate use was associated with a lower risk of delayed dispensing in both sexes (relative risk [RR] 0.28, 95% confidence interval [CI] 0.21-0.39). Older patients ( ≥ 85 years old versus 50-64 years old, RR 0.38, 95% CI 0.22-0.64) had a lower risk of delayed dispensing. Males with anxiety (RR 9.80, 95% CI 2.24-42.9) and females with previous falls had increased risk of early discontinuation (RR 1.80, 95% CI 1.16-2.78).

CONCLUSION

Two-thirds of patients demonstrated good adherence to oral bisphosphonates over 12 months following hip fracture. Efforts to further increase post-discharge antiresorptive use should be sex-specific and address possible persistent uncertainty around delaying treatment initiation.

Catgut embedding in acupoints combined with repetitive transcranial magnetic stimulation for the treatment of postmenopausal osteoporosis: study protocol for a randomized clinical trial

Background

To date, the clinical modulation for bone metabolism based on the neuro-bone mass regulation theory is still not popular. The stimulation of nerve systems to explore novel treatments for Postmenopausal osteoporosis (PMOP) is urgent and significant. Preliminary research results suggested that changes brain function and structure may play a crucial role in bone metabolism with PMOP. Thus, we set up a clinical trial to investigate the effect of the combination of repetitive transcranial magnetic stimulation (rTMS) and catgut embedding in acupoints (CEA) for PMOP and to elucidate the central mechanism of this neural stimulation in regulating bone metabolism.

Method

This trial is a prospective and randomized controlled trial. 96 PMOP participants will be randomized in a 1:1:1 ratio into a CEA group, an rTMS group, or a combined one. Participants will receive CEA, rTMS, or combined therapy for 3 months with 8 weeks of follow-up. The primary outcomes will be the changes in Bone Mineral Density scores, total efficiency of Chinese Medicine Symptoms before and after treatment. Secondary outcomes include the McGill Pain Questionnaire Short-Form, Osteoporosis Symptom Score, Mini-Mental State Examination, and Beck Depression Inventory-II. The leptin, leptin receptor, and norepinephrine levels of peripheral blood must be measured before and after treatment. Adverse events that occur during the trial will be recorded.

Discussion

CEA achieves brain-bone mass regulation through the bottom-up way of peripheral-central while rTMS achieves it through the top-down stimulation of central-peripheral. CEA combined with rTMS can stimulate the peripheral-central at the same time and promote peripheral bone mass formation. The combination of CEA and rTMS may play a coordinating, synergistic, and side-effect-reducing role, which is of great clinical significance in exploring better treatment options for PMOP.Clinical trial registration: https://www.chictr.org.cn/, identifier ChiCTR2300073863.

The Association Between SHBG and Osteoporosis: A NHANES Cross-Sectional Study and A Bidirectional Mendelian Randomization

This study aimed to examine the association between sex hormone-binding globulin (SHBG) and osteoporosis through a cross-sectional study and a two-sample bidirectional Mendelian randomization (MR). We used the National Health and Nutrition Examination Survey (NHANES) 2013-2014 and 2015-2016 data, with exposure as serum SHBG and outcome as osteoporosis and performed multivariate logistic regression to test the correlation between SHBG and osteoporosis. To determine the causal relationship between SHBG and osteoporosis, a two-sample bidirectional MR was employed. The genome-wide association study (GWAS) dataset for SHBG (n = 189,473) was obtained from the IEU database, and the GWAS dataset for osteoporosis (n = 212,778) was obtained from the FinnGen bioBank. The principal MR technique was inverse-variance weighting (IVW). In MR analyses, the MR-Egger intercept and Cochran Q test were used to detect multiple validity and horizontal heterogeneity. 1249 older adult participants (age ≥ 60) were involved in the cross-sectional study, including 113 osteoporosis cases. We identified a significant relationship between circulating SHBG concentration and osteoporosis risk [OR 3.963, 95% CI (2.095-7.495), P < 0.05]. Subgroup analysis indicated that SHBG was closely linked to the risk of osteoporosis in the female population [OR 1.008, 95% CI (1.002-1.013), P = 0.005] but not in males (P = 0.065). In addition, The IVW approach suggested a causal connection between SHBG and increased osteoporosis risk [OR 1.479, 95% CI (1.144-1.912), P = 0.003], and the MR-Egger intercept and the Cochran Q test validated the consistency of the MR results. Finally, the reverse MR analysis declined to identify a causal relation between SHBG and osteoporosis. Our research demonstrates a significant causal connection between circulating SHBG levels and increased osteoporosis risk. These results indicate that high SHBG may be associated with the risk of osteoporosis in postmenopausal women, but more research is needed.

Safety and efficacy of sequential treatments for postmenopausal osteoporosis: a network meta-analysis of randomised controlled trials

Background

The sequential anti-osteoporotic treatment for women with postmenopausal osteoporosis (PMO) is important, but the order in which different types of drugs are used is confusing and controversial. Therefore, we performed a network meta-analysis to compare the efficacy and safety of available sequential treatments to explore the most efficacious strategy for long-term management of osteoporosis.

Methods

In this network meta-analysis, we searched the PubMed, EMBASE, Web of Science, the Cochrane Library, and ClinicalTrials.gov from inception to September 19, 2023 to identify randomised controlled trials comparing sequential treatments for women with PMO. The identified trials were screened by reading the title and abstract, and only randomised clinical trials involving sequential anti-osteoporotic treatments and reported relevant outcomes for PMO were included. The main outcomes included vertebral fracture risk, the percentage change in bone mineral density (BMD) in different body parts, and all safety indicators in the stage after switching treatment. A frequentist network meta-analysis was performed using the multivariate random effects method and evaluated using the surface under the cumulative ranking curve (SUCRA). Certainty of evidence was assessed using the Confidence in the Network Meta-Analysis (CINeMA) framework. This study is registered with PROSPERO: CRD42022360236.

Findings

A total of 19 trials comprising 18,416 participants were included in the study. Five different sequential treatments were investigated as the main interventions and compared to the corresponding control groups. The intervention groups in this study comprised the following treatment switch protocols: switching from an anabolic agent (AB) to an anti-resorptive agent (AR) (ABtAR), transitioning from one AR to another AR (ARtAAR), shifting from an AR to an AB (ARtAB), switching from an AB to a combined treatment of AB and AR (ABtC), and transitioning from an AR to a combined treatment (ARtC). A significant reduction in the incidence of vertebral fractures was observed in ARtC, ABtAR and ARtAB in the second stage, and ARtC had the lowest incidence with 81.5% SUCRA. ARtAAR and ABtAR were two effective strategies for preventing fractures and improving BMD in other body parts. Especially, ARtAAR could improve total hip BMD with the highest 96.1% SUCRA, and ABtAR could decrease the risk of total fractures with the highest 94.3% SUCRA. Almost no difference was observed in safety outcomes in other comparisons.

Interpretation

Our findings suggested that the ARtAAR and ABtAR strategy are the effective and safe sequential treatment for preventing fracture and improving BMD for PMO. ARtC is more effective in preventing vertebral fractures.

Funding

The National Natural Science Foundation of China (82170900, 81970762), the Hunan Administration of Traditional Chinese Medicine, and the Hunan Province High-level Health Talents "225" Project.

Diagnosis and Management of Osteoporosis: A Comprehensive Review of Guidelines

Importance

Osteoporosis causes increased morbidity and mortality, and thus poses a significant economic burden to the health systems worldwide.

Objective

The aim of this study was to review and compare the most recently published major guidelines on diagnosis and management of this common medical entity.

Evidence Acquisition

A thorough comparative review of the most influential guidelines from the RACGP (Royal Australian College of General Practitioners), the ESCEO-IOF (European Society for Clinical and Economic Aspects of Osteoporosis-International Osteoporosis Foundation), the NOGG (National Osteoporosis Guideline Group), the NAMS (North American Menopause Society), the ES (Endocrine Society), and the ACOG (American College of Obstetricians and Gynecologists) was conducted.

Results

The reviewed guidelines generally agree on the definition, the criteria, and investigations used to diagnose osteoporosis. They also concur regarding the risk factors for osteoporosis and the suggested lifestyle modifications (calcium and vitamin D intake, normal body weight, reduction of alcohol consumption, and smoking cessation). However, there is lack of consensus on indications for fracture risk assessment in the general population and the exact indications for bone mineral density assessment. Referral to a bone specialist is reserved for complex cases of osteoporosis (NOGG, NAMS, and ACOG) or in case of inadequate access to care (RACGP). The use of hip protectors to reduce the risk of fractures is supported by RACGP, NOGG, and NAMS, solely for high-risk elderly patients in residential care settings. All guidelines reviewed recognize the efficacy of the pharmacologic agents (ie, bisphosphonates, denosumab, hormone therapy, and parathyroid hormone analogs). Nonetheless, recommendations regarding monitoring of pharmacotherapy differ, primarily in the case of bisphosphonates. The proposed intervals of repeat bone mineral density testing after initiation of drug therapy are set at 2 years (RACGP), 1-3 years (NAMS, ES, and ACOG), or 3-5 years (ESCEO-IOF and NOGG). All guidelines agree upon the restricted use of bone turnover markers only in bone specialist centers for treatment monitoring purposes. Finally, the definition of treatment failure varies among the reviewed guidelines.

Conclusions

Osteoporosis is a distressing condition for women, mainly those of postmenopausal age. Thus, it seems of paramount importance to develop consistent international practice protocols for more cost-effective diagnostic and management techniques, in order to improve women's quality of life.

Identification of ROCK1 as a novel biomarker for postmenopausal osteoporosis and pan-cancer analysis

BACKGROUND

Postmenopausal osteoporosis (PMOP) is a prevalent bone disorder with significant global impact. The elevated risk of osteoporotic fracture in elderly women poses a substantial burden on individuals and society. Unfortunately, the current lack of dependable diagnostic markers and precise therapeutic targets for PMOP remains a major challenge.

METHODS

PMOP-related datasets GSE7429, GSE56814, GSE56815, and GSE147287, were downloaded from the GEO database. The DEGs were identified by "limma" packages. WGCNA and Machine Learning were used to choose key module genes highly related to PMOP. GSEA, DO, GO, and KEGG enrichment analysis was performed on all DEGs and the selected key hub genes. The PPI network was constructed through the GeneMANIA database. ROC curves and AUC values validated the diagnostic values of the hub genes in both training and validation datasets. xCell immune infiltration and single-cell analysis identified the hub genes' function on immune reaction in PMOP. Pan-cancer analysis revealed the role of the hub genes in cancers.

RESULTS

A total of 1278 DEGs were identified between PMOP patients and the healthy controls. The purple module and cyan module were selected as the key modules and 112 common genes were selected after combining the DEGs and module genes. Five Machine Learning algorithms screened three hub genes (KCNJ2, HIPK1, and ROCK1), and a PPI network was constructed for the hub genes. ROC curves validate the diagnostic values of ROCK1 in both the training (AUC = 0.73) and validation datasets of PMOP (AUC = 0.81). GSEA was performed for the low-ROCK1 patients, and the top enriched field included protein binding and immune reaction. DCs and NKT cells were highly expressed in PMOP. Pan-cancer analysis showed a correlation between low ROCK1 expression and SKCM as well as renal tumors (KIRP, KICH, and KIRC).

CONCLUSIONS

ROCK1 was significantly associated with the pathogenesis and immune infiltration of PMOP, and influenced cancer development, progression, and prognosis, which provided a potential therapy target for PMOP and tumors. However, further laboratory and clinical evidence is required before the clinical application of ROCK1 as a therapeutic target.

Management of perimenopausal and menopausal symptoms

Most women worldwide experience menopausal symptoms during the menopause transition or postmenopause. Vasomotor symptoms are most pronounced during the first four to seven years but can persist for more than a decade, and genitourinary symptoms tend to be progressive. Although the hallmark symptoms are hot flashes, night sweats, disrupted sleep, and genitourinary discomfort, other common symptoms and conditions are mood fluctuations, cognitive changes, low sexual desire, bone loss, increase in abdominal fat, and adverse changes in metabolic health. These symptoms and signs can occur in any combination or sequence, and the link to menopause may even be elusive. Estrogen based hormonal therapies are the most effective treatments for many of the symptoms and, in the absence of contraindications to treatment, have a generally favorable benefit:risk ratio for women below age 60 and within 10 years of the onset of menopause. Non-hormonal treatment options are also available. Although a symptom driven treatment approach with individualized decision making can improve health and quality of life for midlife women, menopausal symptoms remain substantially undertreated by healthcare providers.

Osteoarthritis and sarcopenia-related traits: the cross-sectional study from NHANES 2011-2014 and Mendelian randomization study

BACKGROUND

Osteoarthritis (OA) and sarcopenia are common musculoskeletal disorders in the aged population, and a growing body of evidence indicated that they mutually influence one another. Nevertheless, there was still substantial controversy and uncertainty about the causal relationship between sarcopenia and OA. We explored the complex association between sarcopenia-related traits and OA using cross-sectional analysis and Mendelian randomization (MR).

METHODS

The cross-sectional study used the data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Weighted multivariable-adjusted logistic regression and subgroup analyses were used to evaluate the correlation between sarcopenia, grip, appendicular lean mass (ALM) and the risk of OA. Then, we further performed MR analysis to examine the causal effect of sarcopenia-related traits (grip strength, ALM) on OA. Instrumental variables for grip strength and ALM were from the UK Biobank, and the summary-level data for OA was derived from the Genetics of Osteoarthritis (GO) Consortium GWAS (n = 826,690).

RESULTS

In this cross-sectional analysis, we observed that sarcopenia, grip were significantly linked with the risk of OA (OR 1.607, 95% CI 1.233-2.094, P < 0.001), (OR 0.972, 95% CI 0.964-0.979, P < 0.001). According to subgroup analyses stratified by gender, body mass index (BMI), and age, the significant positive relationship between sarcopenia and OA remained in males, females, the age (46-59 years) group, and the BMI (18.5-24.9 kg/m²) group (P < 0.05). Furthermore, MR analysis and sensitivity analyses showed causal associations between right grip, left grip and KOA (OR 0.668; 95% CI 0.509 to 0.877; P = 0.004), (OR 0.786; 95% CI 0.608 to 0.915; P = 0.042). Consistent directional effects for all analyses were observed in both the MR-Egger and weighted median methods. Subsequently, sensitivity analyses revealed no heterogeneity, directional pleiotropy or outliers for the causal effect of grip strength on KOA (P > 0.05).

CONCLUSIONS

Our research provided evidence that sarcopenia is correlated with an increased risk of OA, and there was a protective impact of genetically predicted grip strength on OA. These findings needed to be verified in further prospective cohort studies with a large sample size.

Fracture risk after deprescription of bisphosphonates: Application of real-world data in primary care

PURPOSE

To compare the effect of discontinuing bisphosphonate treatment on fracture risk in postmenopausal women at high versus low risk of fracture.

DESIGN

Retrospective, longitudinal and population-based cohort study.

SETTING

Barcelona City Primary Care. Catalan Health Institute.

PARTICIPANTS

All women attended by primary care teams who in January 2014 had received bisphosphonate treatment for at least five years were included and followed for another five years.

INTERVENTION

Patients were classified according to their risk of new fractures, defined as those who had a history of osteoporotic fracture and/or who received treatment with an aromatase inhibitor, and the continuity or deprescription of the bisphosphonate treatment was analyzed over fiver year follow-up.

MAIN MEASUREMENTS

The cumulative incidence of fractures and the incidence density were calculated and analyzed using logistic regression and Cox models.

RESULTS

We included 3680 women. There were no significant differences in fracture risk in high-risk women who discontinued versus continued bisphosphonate treatment (hazard ratio [HR] 1.17, 95% confidence interval [CI] 0.87-1.58 for total osteoporotic fractures). However, discontinuers at low risk had a lower incidence of fracture than continuers. This difference was significant for vertebral fractures (HR 0.64, 95% CI 0.47-0.88) and total fractures (HR 0.77, 95% CI 0.64-0.92).

CONCLUSION

Our results suggest that deprescribing bisphosphonates in women who have already received five years of treatment does not increase fracture risk. In low-risk women, continuing this treatment might could even favor the appearance of new osteoporotic fractures.

Long non-coding RNA KCNQ1OT1 alleviates postmenopausal osteoporosis by modulating miR-421-3p/mTOR axis

The prevention and treatment of postmenopausal osteoporosis (PMOP) is a significant public health issue, and non-coding RNAs are of vital importance in this process. In this study, we find that the long non-coding RNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (lncRNA KCNQ1OT1) can alleviate the ovariectomy-induced (OVX) PMOP in vivo. We determined that over-expression of KCNQ1OT1 could enhance functions of MC3T3-E1 cells, whereas an opposite trend was observed when KCNQ1OT1 was knocked down. Subsequently, miR-421-3p targeting KCNQ1OT1 was detected through a database search, and RNA fluorescent in situ hybridization, RNA immunoprecipitation, dual luciferase reporter assays all verified this relationship. Notably, KCNQ1OT1 stifled the miR-421-3p expression. The inhibition of proliferation, migration, and osteogenic differentiation caused by KCNQ1OT1 knock-down were reversed by an miR-421-3p inhibitor, further confirming the above findings. We verified that miR-421-3p specifically targeted the mammalian target of rapamycin (mTOR), and miR-421-3p inhibitor could reverse the negative effects of small interfering RNA of mTOR (si-mTOR) on MC3T3-E1 cells. Finally, osteoblasts isolated and cultured from OVX mice model and control mice also confirmed the observed trend. In combination, results mentioned above reveal that KCNQ1OT1 regulates MC3T3-E1 cell functions by regulating the miR-421-3p/mTOR axis.

Advances in Animal Models for Studying Bone Fracture Healing

Fracture is a common traumatic injury that is mostly caused by traffic accidents, falls, and falls from height. Fracture healing is a long-term and complex process, and the mode of repair and rate of healing are influenced by a variety of factors. The prevention, treatment, and rehabilitation of fractures are issues that urgently need to be addressed. The preparation of the right animal model can accurately simulate the occurrence of fractures, identify and observe normal and abnormal healing processes, study disease mechanisms, and optimize and develop specific treatment methods. We summarize the current status of fracture healing research, the characteristics of different animal models and the modeling methods for different fracture types, analyze their advantages and disadvantages, and provide a reference basis for basic experimental fracture modeling.

Mendelian randomization analysis does not reveal a causal influence of mental diseases on osteoporosis

Introduction

Osteoporosis (OP) is primarily diagnosed through bone mineral density (BMD) measurements, and it often leads to fracture. Observational studies suggest that several mental diseases (MDs) may be linked to OP, but the causal direction of these associations remain unclear. This study aims to explore the potential causal association between five MDs (Schizophrenia, Depression, Alzheimer's disease, Parkinson's disease, and Epilepsy) and the risk of OP.

Methods

First, single-nucleotide polymorphisms (SNPs) were filtered from summary-level genome-wide association studies using quality control measures. Subsequently, we employed two-sample Mendelian randomization (MR) analysis to indirectly analyze the causal effect of MDs on the risk of OP through bone mineral density (in total body, femoral neck, lumbar spine, forearm, and heel) and fractures (in leg, arm, heel, spine, and osteoporotic fractures). Lastly, the causal effect of the MDs on the risk of OP was evaluated directly through OP. MR analysis was performed using several methods, including inverse variance weighting (IVW)-random effects, IVW-fixed effects, maximum likelihood, weighted median, MR-Egger regression, and penalized weighted median.

Results

The results did not show any evidence of a causal relationship between MDs and the risk of OP (with almost all P values > 0.05). The robustness of the above results was proved to be good.

Discussion

In conclusion, this study did not find evidence supporting the claim that MDs have a definitive impact on the risk of OP, which contradicts many existing observational reports. Further studies are needed to determine the potential mechanisms of the associations observed in observational studies.