Muscle and bone, two interconnected tissues

Inhibition of SFRP1 by microRNA‑206‑3p may be the underlying cause of osteosarcopenia

Osteosarcopenia is characterized by a simultaneous decrease in bone mass and muscle quality. Thus, determining the common pathogenesis between osteoporosis and sarcopenia may aid in identifying a solution. Secreted frizzled-related protein 1 (SFRP1), a Wnt/β-catenin pathway inhibitor, reportedly decreases during the osteogenesis process and is increased in osteoporosis and sarcopenia mice models. As microRNAs (miRNAs/miRs) can regulate the expression of multiple proteins, the present study aimed to determine if miR-206-3p can promote the nuclear translocation of β-catenin by inhibiting SFRP1 during both osteogenesis and myogenesis. Transcriptome sequencing revealed that SFRP1 was markedly upregulated in the BMSCs derived from ovariectomized mice. In vitro induction of osteogenesis confirmed that SFRP1 negatively regulated osteogenesis. A luciferase reporter assay confirmed that miR-206-3p downregulated SFRP1 by directly binding to the 3' untranslated region. Subsequently, the BMSC and L6 cells were transfected with an miR-206-3p inhibitor or a corresponding negative control. Immunoblotting was performed to assess the relative expression levels of SFRP1 and Wnt/β-catenin signaling. The mRNA levels of SFRP1, osteogenesis-related molecules and myogenesis-related molecules were also detected by quantitative real-time PCR. The miR-206-3p inhibitor reduced the expression of osteogenesis- and myogenesis-related molecules and inactivated the Wnt/β-catenin signaling by releasing SFRP1. In conclusion, miR-206-3p downregulated SFRP1 and activated Wnt/β-catenin signaling to promote osteogenesis and myogenesis. Thus, miR-206-3p may be an important therapeutic target in osteosarcopenia. The present study aimed to uncover the genes and mechanisms that co-regulate muscle and bone. SFRP1, a known regulator of osteoporosis, was examined by analyzing its upstream regulatory microRNA and validating its molecular role. The diagnostic and therapeutic potential of miR-206-3p for osteomyopenia was evaluated by first focusing on osteoporosis and then validating findings with myofibroblasts. These data suggested that miR-206-3p can serve as a therapeutic target for osteomyopenia by inhibiting SFRP1, thereby activating the Wnt/β-catenin signaling pathway and promoting both osteogenesis and myogenesis.

Assessing bone and muscle health and their association in a Mongolian population aged 40 and older: a pioneering observational study

This study in Mongolia reveals that weaker grip strength and higher sarcopenia risk are linked to greater fracture risk and lower bone density. It highlights the crucial interplay between muscle and bone health, emphasizing the need for integrated musculoskeletal assessments to prevent fractures, especially in aging populations.

BACKGROUND

Research on the relationship between bone and muscle health in low- and middle-income countries, particularly Central Asia, remains limited.

OBJECTIVES

To explore the correlation between muscle and bone health and to estimate the FRAX risk for major osteoporotic fractures (MOF) and hip fractures in the Mongolian population, stratified by age and sex.

METHODS

A cross-sectional study was conducted in Ulaanbaatar and regional Mongolia from May to August 2024. Handgrip strength, sarcopenia risk (SARC-F) and bone mineral density using peripheral DXA (BMD T-score) were assessed. Fracture risks were estimated using the FRAX model.

RESULTS

Participants (n = 857; median age, 52 years; 53.0% women) had a median grip strength of 28 kg and a median BMD T-score of - 1.9. Most (69.5%) were at low sarcopenia risk (SARC-F < 4). SARC-F was moderately correlated with FRAX scores for MOF and hip fractures (r ≈ 0.27, p < 0.001) while grip strength was negatively correlated with FRAX scores(r =  - 0.24, p < 0.001). Grip strength positively correlated with BMD T-scores (r = 0.22, p < 0.001). Fracture risks increased with age, with women showing higher rates than men. Higher sarcopenia risk (SARC-F ≥ 4) was associated with lower BMD and increased fracture risk. Lower grip strength (< 18 kg for women, < 28 kg for men) was linked to higher fracture risk and lower BMD.

CONCLUSIONS

This study highlights the interconnected nature of muscle and bone health in the Mongolian population, demonstrating that lower grip strength and higher sarcopenia risk are significantly associated with increased fracture risk and reduced bone density. These findings underscore the importance of integrated strategies for musculoskeletal health assessment and fracture prevention, particularly in aging populations.

HBP-A Attenuates Knee Osteoarthritis Progression via MLK3/P38/HDAC4 Axis-Mediated Dual Protection of Articular Cartilage and Quadriceps

Knee osteoarthritis (KOA), a degenerative joint disease driven by biomechanical instability, involves cartilage degradation, muscle dysfunction, and MLK3/P38 MAPK pathway activation. Histone deacetylase 4 (HDAC4), a regulator of chondrocyte and muscle homeostasis, interacts with this pathway during disease progression. While Hyriopsis Bioactive Polysaccharide-Anodonta (HBP-A) exhibits P38 MAPK inhibitory properties in vitro, its in vivo therapeutic effects on musculoskeletal tissues remain uncharacterised. A destabilisation of the medial meniscus (DMM) mouse model was established to investigate HBP-A's therapeutic potential. Animals were randomly divided into sham-operated, DMM-induced, and HBP-A-treated groups. Following surgical induction, HBP-A (0.26 g/kg) was administered daily via oral gavage for 4 weeks. Comprehensive assessments included behavioural tests for pain sensitivity, micro-CT scanning, histological evaluation, and transmission electron microscope. Molecular mechanisms were investigated via immunohistochemical or immunofluorescence staining of MLK3, P38 MAPK, Caspase-3, and HDAC4, complemented by RT-qPCR analysis of myokine expression. HBP-A treatment significantly alleviated pain sensitivity compared to the DMM group. Structural evaluations revealed preserved subchondral bone integrity and attenuated cartilage degeneration, with histological scoring confirming reduced pathological changes. Quadriceps exhibited mitigated atrophy and restored ultrastructural organisation. Molecular profiling demonstrated suppressed MLK3/P38 MAPK pathway activation, diminished apoptotic activity, and elevated HDAC4 expression in both cartilage and quadriceps. HBP-A additionally normalised dysregulated expression of muscle-derived osteogenic factors linked to bone-cartilage crosstalk. These findings establish HBP-A as a dual-target therapeutic agent for KOA, concurrently mitigating cartilage and muscle degeneration through MLK3/P38 MAPK/HDAC4 axis modulation.

Skeletal muscle activity affects the deformity of long bone morphology in lathyritic chick embryo

Embryonic muscle activity is involved in various aspects of bone morphogenesis and growth. Normal mechanical stimuli of muscle contraction are important in most cases, and when the muscles are immobilized, the developing bones are abnormally shaped. In chick embryos, a characteristic curved deformity is reproducibly induced in the developing tibiotarsus using the bone-weakening agent, beta-aminopropionitrile (bAPN). In this study, we applied decamethonium bromide (DMB), a well-established neuromuscular blocking agent, to embryos treated with bAPN, to test the hypothesis that the deformity is triggered and formed depending on the balance between the decrease in stiffness of the bAPN-affected tibiotarsus and the normal physiological increase in embryonic skeletal muscle activity. The occurrence of curved morphology induced by bAPN administered at 4 or 8 days of incubation (embryonic day [ED]) was temporally consistent with the posterior displacement of the leg muscles, which occurred just before ED8. The displaced muscles were assumed to exert a contraction force comparable to that of untreated normal muscles. When treated with DMB at ED8, the muscles atrophied and exhibited degenerative changes, and the degree of curved morphology was alleviated and reduced to 50% or more in the morphometric evaluation at ED10. These findings indicated that the coordinated development of skeletal element stiffness and muscle activity must be temporally regulated, particularly during the early stages of skeletogenesis.

Association of body mass index and sarcopenia with osteoporosis: a predictive nomogram model for risk assessment

Objective

Body mass index (BMI) and sarcopenia are linked to osteoporosis, but the extent to which BMI influences osteoporosis through sarcopenia remains unclear. This study aims to assess the associations between BMI, sarcopenia, and osteoporosis, and to explore the predictive value of their combined biochemical markers for osteoporosis.

Methods

We retrospectively collected clinical data from 813 inpatients in the endocrinology department to explore the relationships between serum markers and skeletal muscle mass or BMI, and to evaluate the predictive value of BMI and sarcopenia for osteoporosis. Mediation analysis was employed to examine the associations among BMI, sarcopenia, and osteoporosis. Participants were randomly divided into training (n = 407) and testing (n = 406) sets (5:5). Independent risk factors were identified using least absolute shrinkage and selection operator and logistic regression, leading to the development of a nomogram model. Model evaluation was conducted through receiver operating characteristic curves, confusion matrices, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC).

Results

BMI and skeletal muscle mass were negatively correlated with serum 25-hydroxyvitamin D and calcium levels. The "BMI < 28 and Non-Sarcopenia" emerged as a protective factor against osteoporosis. Sarcopenia significantly mediated the association between BMI and osteoporosis (46.88%). Gender, age, high-density lipoprotein, alkaline phosphatase, BMI, and sarcopenia emerged as independent predictors of osteoporosis. The area under the curve (AUC) for the training and testing sets was 0.859 and 0.866, respectively, with calibration curves indicating good consistency. DCA and CIC demonstrated clinical net benefits at risk thresholds of 0.02-0.82 and 0.02-0.67. Sankey diagrams and partial AUCs (1.00-0.75 sensitivity and specificity) illustrate the significant negative predictive value of BMI and sarcopenia.

Conclusion

Lower BMI and non-sarcopenia are negatively associated with the risk of osteoporosis. In addition, the nomogram demonstrates good predictive value, with a greater negative predictive value of the BMI and sarcopenia.

Sarcopenic obesity and weight loss-induced muscle mass loss

PURPOSE OF REVIEW

Sarcopenic obesity is a clinical condition characterized by the coexistence of excess adiposity and impaired muscle function, associated with heightened cardiometabolic risk and frailty. The emergence of new incretin-based obesity management medications (OMMs), which allow unprecedented weight loss, has raised concerns regarding weight loss-induced fat-free mass (FFM) reduction, including skeletal muscle mass (SMM). This review examines recent findings on the prevalence, diagnosis, and implications of sarcopenic obesity, explores the effects of weight-loss interventions on body composition and their impact on health, and discusses strategies to preserve muscle mass.

RECENT FINDINGS

Weight loss induced by incretin-based OMMs results in a variable but significant reduction in FFM. The extent to which this loss affects SMM and function remains uncertain. Nutritional strategies, particularly adequate protein intake, and structured exercise interventions, especially resistance training, play a key role in mitigating FFM loss. Digital health interventions and telemedicine-based exercise programs offer promising approaches for maintaining muscle health during weight loss.

SUMMARY

The clinical significance of FFM loss during weight reduction remains debated. Future research should refine sarcopenic obesity diagnostic criteria, assess the long-term impact of FFM/SMM reduction during intentional weight loss, and evaluate interventions that optimize body composition while preserving functional health.

Effect of different types of exercise on bone mineral density in postmenopausal women: a systematic review and network meta-analysis

Postmenopausal women (PMW) experience the decline of ovarian function; estrogen reduction will accelerate bone mass loss. Exercise is an effective means of mitigating bone mineral density (BMD) loss in PMW, but the relative effectiveness of different exercise types remains under investigation. Our study encompassed a thorough assessment and network meta-analysis, following the principles specified in the Preferred Reporting Items for Systematic Reviews and Network Meta-analysis (PRISMA) statement. Data sources and searches Literature search databases include PubMed, Embase, Cochrane, Google Scholar, Web of Science (WOS), and Scopus. The data search combined keywords like bone mineral density (BMD), postmenopausal women, and various exercise types. Data synthesis and analysis Perform a network meta-analysis by integrating both direct and indirect comparisons using the R environment. This network meta-analysis aimed to evaluate and compare various exercise types with bone mineral density in PMW to identify the most effective types. The literature comprised a collective of 49 papers, encompassing 3360 people across eight interventions. The Network Meta-analysis ranked the effects of exercise interventions on lumbar spine BMD in descending order, based on the p-scores assigned to them in the forest plot. The exercise modalities that showed significant efficacy were AE + RT(Aerobic Mixed Resistance Exercise, MD = 32.35, 95% CrI [8.08;56.62], p = 0.87), AE(Aerobic Exercise, MD = 22.33, 95% CrI [6.67;37.99], p = 0.74), and RT(Resistance Training, MD = 16.98, 95% CrI [8.98;24.99], p = 0.60). Similarly, the femoral neck sites were ranked in descending order based on their p-scores in the forest plot, and the exercise patterns with significant effects on lumbar spine bone mineral density were AE + RT(MD = 140, 95% CrI [40.89;239.11], p = 0.99), WBV(Whole Body Vibration, MD = 26.07, 95% CrI [2.97;49.16], p = 0.80), and RT(MD = 16.98, 95% CrI [8.98;24.99], p = 0.72). Exercise intervention significantly and effectively alleviated BMD in postmenopausal women, with AE + RT having the best effect.

Biomimetic Microstructured Scaffold with Release of Re-Modified Teriparatide for Osteoporotic Tendon-to-Bone Regeneration via Balancing Bone Homeostasis

Osteoporotic tendon-to-bone interface healing is challenging, with a high surgical repair failure rate of up to 68%. Conventional tissue engineering approaches have primarily focused on promoting interface healing by stimulating regeneration in either the tendon or bone. However, these methods often fall short of achieving optimal therapeutic outcomes due to their neglect of balancing bone homeostasis and remodeling the microstructure at the osteoporotic tendon-to-bone interface. Herein, a series of site-specific functional modifications are carried out on teriparatide to develop recombinant human parathyroid hormone (R-PTH). A biomimetic microstructured reconstruction scaffold (BMRP) is constructed using a decalcified mussel shell scaffold, pre-gel, and R-PTH. The BMRP mimics the microstructures of the native tendon-to-bone interface and restores the original structure of the interface tissue by repairing injured cells, balancing bone homeostasis, and remodeling the microstructure of the osteoporotic tendon-to-bone interface. In an osteoporotic rotator cuff tear model, BMRP is in situ implanted at the injured site, resulting in structural reconstruction and functional recovery. The BMRP demonstrates excellent repair effects, representing a novel therapeutical alternative for treating osteoporotic tendon-to-bone injury potential for clinical application.

Relationship between muscle size and density and proximal femoral bone mineral density in elderly men with hip fractures across different age groups

AIMS

To investigate the relationship between muscle size and density and bone mineral density (BMD) of the proximal femur in elderly men with hip fractures (HF) across different age groups.

METHODS

Quantitative computed tomography (QCT) was conducted on the hip joints of 300 male patients with low-energy acute HF to measure areal BMD (aBMD). Concurrently, the cross-sectional area and density of the gluteal and thigh muscles surrounding the hip were assessed. Multivariable linear regression models were utilized to evaluate the associations between muscle characteristics and BMD across various age groups and fracture types.

RESULTS

After adjusting for BMI covariates, all measures of aBMD in the femoral neck fracture (FNF) group were significantly positively correlated with mid-thigh muscle (MM) area in patients aged 75 years and older (P < 0.05). In contrast, thigh muscle density did not show a significant correlation. In patients younger than 75 years, there was a positive correlation between MM density and total hip (TH) aBMD in the FNF group (B, 9.077; 95% CI, 1.577-16.577; P = 0.018). In the ITF group, no muscle parameters were found to be associated with aBMD.

CONCLUSIONS

Our study demonstrated that in the FNF group aged 75 and older, thigh muscle size, but not density, was positively correlated with the BMD parameters of the proximal femur. Therefore, thigh muscle size may serve as a more clinically significant target for preventing FNF in older men.

Comprehensive Diagnostic Value of Vertebral Bone Quality Scores and Paravertebral Muscle Quality Parameters in Osteoporotic Vertebral Fractures

OBJECTIVE

Both vertebral bone quality (VBQ) scores and paravertebral muscle quality can predict osteoporotic vertebral fractures (OVFs). This study aimed to compare the diagnostic value of opportunistic VBQ scores and sarcopenia for OVF and to determine if their combined use could enhance diagnostic efficacy.

METHODS

A total of 194 patients, matched 1:1 by age and sex, were included. VBQ scores and paravertebral muscle cross-sectional areas (CSAs) were measured from lumbar magnetic resonance imaging. Independent risk factors for OVF were determined using multivariate conditional logistic regression. The predictive value of VBQ and muscle-related parameters for OVF were assessed with receiver operating characteristic curves.

RESULTS

VBQ, CSA, and degree of fat infiltration (DFF) showed significant differences between the fracture and nonfracture groups (P < 0.001). Multivariate analysis identified lower multifidus (MF) CSA, higher MF DFF, and higher VBQ as independent risk factors for OVF. Thresholds of 3.46 for VBQ and 11.83 cm2 for MF CSA yielded area under the curve values of 0.668 and 0.736, respectively, for predicting OVF. Combining VBQ and MF CSA notably enhanced the sensitivity and specificity of OVF diagnosis.

CONCLUSIONS

The predictive value of MF CSA in anticipating OVF was marginally superior to that of VBQ and MF DFF. Furthermore, the concurrent utilization of VBQ and MF CSA substantially enhanced the diagnostic accuracy of OVF. Considering that both VBQ and MF CSA can be opportunistically obtained during routine examinations, individuals with a VBQ ≥3.46 and MF CSA ≤11.83 cm2 should be categorized as high risk for OVF, warranting timely preventive measures.

Exerkines and Sarcopenia: Unveiling the Mechanism Behind Exercise-Induced Mitochondrial Homeostasis

Background/Objectives: Sarcopenia, characterized by the progressive loss of muscle mass and strength, is linked to physical disability, metabolic dysfunction, and an increased risk of mortality. Exercise therapy is currently acknowledged as a viable approach for addressing sarcopenia. Nevertheless, the molecular mechanisms behind exercise training or physical activity remain poorly understood. The disruption of mitochondrial homeostasis is implicated in the pathogenesis of sarcopenia. Exercise training effectively delays the onset of sarcopenia by significantly maintaining mitochondrial homeostasis, including promoting mitophagy, improving mitochondrial biogenesis, balancing mitochondrial dynamics, and maintaining mitochondrial redox. Exerkines (e.g., adipokines, myokines, hepatokines, and osteokines), signaling molecules released in response to exercise training, may potentially contribute to skeletal muscle metabolism through ameliorating mitochondrial homeostasis, reducing inflammation, and regulating protein synthesis as a defense against sarcopenia. Methods: In this review, we provide a detailed summary of exercise-induced exerkines and confer their benefit, with particular focus on their impact on mitochondrial homeostasis in the context of sarcopenia. Results: Exercise induces substantial adaptations in skeletal muscle, including increased muscle mass, improved muscle regeneration and hypertrophy, elevated hormone release, and enhanced mitochondrial function. An expanding body of research highlights that exerkines have the potential to regulate processes such as mitophagy, mitochondrial biogenesis, dynamics, autophagy, and redox balance. These mechanisms contribute to the maintenance of mitochondrial homeostasis, thereby supporting skeletal muscle metabolism and mitochondrial health. Conclusions: Through a comprehensive investigation of the molecular mechanisms within mitochondria, the context reveals new insights into the potential of exerkines as key exercise-protective sensors for combating sarcopenia.

Skeletal Muscle Measurements Based on Abdominal Computerized Tomography (CT) Predict Risk of Osteoporosis in Incident Hemodialysis Patients

Objective: Osteoporosis is prevalent in patients with chronic kidney disease (CKD), with risk increasing as CKD progresses, subsequently elevating fracture risk. While previous studies have shown a link between low skeletal muscle mass and osteoporosis in the general population, there is limited research exploring this relationship in patients with advanced CKD (stages 3-5D). This study aimed to evaluate whether skeletal muscle area (SMA), as measured by abdominal CT, is correlated with bone mineral density (BMD) in advanced CKD patients beginning hemodialysis. Methods: This single-center, retrospective cohort study included patients who started maintenance hemodialysis at Daejeon St. Mary's Hospital from January 2018 to September 2021. Patients who underwent abdominal CT and BMD assessments within three months of dialysis initiation were enrolled, resulting in a sample of 87 individuals. Baseline characteristics were analyzed, with patients stratified by sex and SMA quartiles. Pearson's correlation and multivariate regression analyses were conducted to the relationship between SMA and BMD T-scores. Results: The study cohort had an average age of 65.4 years, with 52.9% of participants being male. Male patients exhibited significantly higher SMA and BMD T-scores in both the lumbar spine and femur compared to female patients. SMA showed the strongest positive correlation with BMD at both sites (lumbar spine, r = 0.424; femur, r = 0.514; p < 0.001). Multivariate analysis identified SMA as an independent positive predictor of BMD, while alkaline phosphatase (ALP) was independently associated with lower femur BMD. In the SMA-based subgroup analysis, patients with lower SMA had significantly lower BMD T-scores and a higher risk of osteoporosis. Logistic regression indicated that patients in the lowest SMA quartile had substantially increased odds of osteoporosis compared to those in the highest quartile, with an adjusted odds ratio of 30.59 (p = 0.008). Conclusions: Lower skeletal muscle mass is significantly associated with lower bone density and a higher risk of osteoporosis in advanced CKD patients initiating hemodialysis. SMA, as measured by abdominal CT, may serve as a useful marker for identifying patients at elevated osteoporosis risk in this population.

Engineering bone/cartilage organoids: strategy, progress, and application

The concept and development of bone/cartilage organoids are rapidly gaining momentum, providing opportunities for both fundamental and translational research in bone biology. Bone/cartilage organoids, essentially miniature bone/cartilage tissues grown in vitro, enable the study of complex cellular interactions, biological processes, and disease pathology in a representative and controlled environment. This review provides a comprehensive and up-to-date overview of the field, focusing on the strategies for bone/cartilage organoid construction strategies, progresses in the research, and potential applications. We delve into the significance of selecting appropriate cells, matrix gels, cytokines/inducers, and construction techniques. Moreover, we explore the role of bone/cartilage organoids in advancing our understanding of bone/cartilage reconstruction, disease modeling, drug screening, disease prevention, and treatment strategies. While acknowledging the potential of these organoids, we discuss the inherent challenges and limitations in the field and propose potential solutions, including the use of bioprinting for organoid induction, AI for improved screening processes, and the exploration of assembloids for more complex, multicellular bone/cartilage organoids models. We believe that with continuous refinement and standardization, bone/cartilage organoids can profoundly impact patient-specific therapeutic interventions and lead the way in regenerative medicine.

Tanshinone IIA alleviates inflammation-induced skeletal muscle atrophy by regulating mitochondrial dysfunction

Skeletal muscle atrophy, characterized by loss of muscle mass and function, is often linked to systemic inflammation. Tanshinone IIA (Tan IIA), a major active constituent of Salvia miltiorrhiza, has anti-inflammatory and antioxidant properties. However, the effect of Tan IIA on inflammation-induced skeletal muscle atrophy remains unclear. Here, a mice model of the inflammatory muscle atrophy was established using lipopolysaccharide (LPS). Tan IIA intervention significantly increased muscle mass and strength, improved muscle fiber size, and maintained the integrity of skeletal muscle mitochondrial morphology in LPS-treated mice. Myotubes derived from myosatellite cells (MUSCs) were exposed to LPS in vitro. Tan IIA treatment inhibited LPS-induced muscle protein degradation and increased myotube diameter. Notably, Tan IIA attenuated LPS-induced inflammatory response and hyperactive mitophagy both in vivo and in vitro. In addition, Tan IIA treatment effectively diminished oxidative stress, inhibited the accumulation of mitochondrial reactive oxygen species (mtROS), and attenuated mitochondrial fission in LPS-treated myotubes. Reducing mtROS production helped to inhibit LPS-induced excessive mitophagy and myotubes atrophy. Together, our results reveal that Tan IIA can protect against inflammation-induced skeletal muscle atrophy by regulating mitochondrial dysfunction, presenting innovative potential therapeutics for skeletal muscle atrophy.

Dietary recommendations of the Moroccan Society of Rheumatology (SMR) for patients with ostéosarcopenia

OBJECTIVE

The objective of this study was to develop the first Moroccan recommendations concerning nutrition in patients with osteosarcopenia.

MATERIAL AND METHODS

A steering committee consisting of rheumatologists and nutritionists drafted the initial version of the recommendations in light of the literature review and the recommendations of international societies. The draft was reviewed by a reading committee of 13 experts to approve the final version.

RESULTS

Four overarching principles and ten recommendations were established. The overarching principles emphasize that nutritional advice is not a substitute for the pharmacological treatment of osteosarcopenia. Instead, it should be based on scientific evidence and take into account the specific characteristics of Moroccan society. The recommendations emphasize the significance of adequate calcium and vitamin D intake while evaluating the benefit-risk ratio in instances where calcium supplementation is indicated. A balanced intake of trace elements, vitamins, proteins, and dairy products should be maintained. The Mediterranean diet is recommended, while vegetarian diets and restrictive diets in individuals who are not overweight are not advised. It is recommended that individuals who fast during Ramadan consume a varied and balanced diet. It is recommended that the consumption of soft drinks and alcohol be limited. The consumption of phytoestrogens from food in moderation is considered beneficial as part of a balanced diet. Nevertheless, the use of supplements is not advised.

CONCLUSION

The purpose of this work is to provide Moroccan rheumatologists with a practical tool to improve the nutritional aspect in patients with osteosarcopenia.

Fracture severity dependence of bone and muscle performance in patients following single or multiple vertebral fractures

BACKGROUND

Few studies focus on the clinical, laboratory, radiological, and biological characteristics of bone and muscle of multiple vertebral fractures, which are associated with a more poor prognosis compared with single fracture.

PURPOSE

To compare the BMD, bone turnover, muscularity, fatty infiltration of muscle, and prevalence of co-morbidities in patients with single and multiple vertebral fractures.

METHODS

We recruited 100 patients with single fracture (age 66.96 ± 8.24 years) and 100 with multiple fractures (age 69.90 ± 7.80 years); performed dual-energy X-ray absorptiometry of the femoral neck, hip, and lumbar vertebrae; and measured biochemical markers of bone turnover, muscularity, and fatty infiltration.

RESULTS

Patients with multiple vertebral fractures had lower hip BMD (p=0.010) than those with single fractures, but there was no difference in femoral neck and lumbar vertebral BMD nor in muscularity. However, fatty infiltration, an indicator of muscle quality, was significantly higher in participants with multiple fractures (p=0.006). Diabetes was significantly more common in patients with multiple fractures (p=0.042). There were no significant differences in markers of bone turnover, and Seperman analyses showed no correlations of CTX-1 or tPINP with the BMD of the hip, femoral neck, or lumbar spine. However, high CTX-1 was associated with high tPINP (r=0.4805; p<0.0001), and marked fatty infiltration was associated with low hip, lumbar vertebral, and femoral neck BMD. Cox regression analyses showed that age (OR 1.057; 95% CI 1.016-1.101; p=0.006) and low hip BMD (OR 0.016; 95% CI, 0.000-0.549; p=0.022) were associated with a higher risk of multiple fractures.

CONCLUSION

Patients with multiple fractures tend to have lower hip BMD, a history of type 2 diabetes, and more substantial fatty infiltration of muscle than in those with single fractures. Age and hip BMD rather than lumbar vertebrae BMD were found to be independent risk factors for multiple vertebral compression fractures, implying that hip BMD may be a more sensitive predictor for multiple vertebral fractures. More improvements in hip BMD and focus on older persons may be useful means of preventing multiple fractures.

Is decreased psoas volume a risk factor for hip fracture? A comparative study of patients with and without hip fractures using the exact matching technique

INTRODUCTION

Sarcopenia is linked to increased fall and hip fracture risk. However, studies often overlook comprehensively controlling for age, sex, bone mineral density (BMD), and body mass index (BMI). Our study aimed to determine if sarcopenia, determined by evaluating the psoas muscle volume, is an independent risk factor for hip fractures. We employed a methodological approach that includes the exact matching technique.

METHODS

In this cross-sectional comparative study, we compared the data of patients who sustained hip fractures between 2015 and 2021 with those of a control group from a health screening center in a single center. The study included 545 patients with hip fractures and 1292 without fractures. We collected data on demographics, BMD determined using dual-energy X-ray absorptiometry, and abdominal and pelvic computed tomography (APCT) scans for psoas muscle volume analysis.

RESULTS

The analysis after exact matching of 266 pairs revealed that psoas volume/height2 was the most significant and dominant risk factor among the evaluated indices. Multivariate logistic regression analysis, adjusting for age, sex, BMI, and BMD, identified height or height2-adjusted psoas muscle volume as an independent risk factor for hip fractures (p = 0.042 and p = 0.002, respectively). Age, female sex, lower BMI, and lower BMD were associated with an increased risk of hip fractures.

CONCLUSION

Decreased psoas muscle volume adjusted for patient height independently predicts hip fracture risk. Psoas volume assessment via APCT is a practical tool for identifying at-risk individuals, emphasizing the necessity of including sarcopenia in hip fracture risk assessments.

Deciphering Osteosarcopenia through the hallmarks of aging

Osteosarcopenia is a major driver of functional loss and a risk factor for falls, fractures, disability and mortality in older adults, urgently requiring the development of effective interventions to address it. The hallmarks of aging provide a theoretical and practical framework that allows for the structured organization of current knowledge and the planning of new development lines. This article comprehensively reviews the currently available literature on the role of the hallmarks of aging in the development of osteosarcopenia, thereby offering a panoramic view of the state of the art and knowledge gaps in this field.

Muscle Performance as a Predictor of Bone Health: Among Community-Dwelling Postmenopausal Japanese Women from Setagaya-Aoba Study

Osteoporosis is a significant health concern for postmenopausal women, necessitating efficient screening methods for bone health. This study explores the potential of muscle function, assessed through the 30-s chair stand test (CS-30), as an indicator for low bone stiffness in this demographic, aiming to establish a practical threshold for large-scale fitness surveillance without the need for specialized tools. We analyzed data from 1055 community-dwelling postmenopausal Japanese women, aged 41-89 years, collected between 2016 and 2019. Participants underwent CS-30 to evaluate muscle function alongside quantitative ultrasound (QUS) measurements to assess bone stiffness. The cohort was divided into two groups for the development and validation of a cutoff point for low bone stiffness, defined as a QUS speed of sound less than 1487.3 m/s. The CS-30 cutoff was determined using receiver operating characteristic (ROC) curve analysis and validated through logistic regression, accounting for age, body mass index, and smoking status. Among 577 postmenopausal women, 16.0% exhibited low bone stiffness. In the development group (n = 382), ROC analysis identified a CS-30 cutoff of 25 repetitions for detecting low bone stiffness, with an area under the curve of 0.744 (P < 0.001). In the validation group (n = 195), participants performing ≥ 25 repetitions had a higher risk of low bone stiffness compared to those performing ≤ 24 repetitions. The CS-30 test is an effective preliminary screening tool for identifying postmenopausal women at risk of low bone stiffness, with a threshold of 25 repetitions. This method could facilitate early detection of individuals at higher osteoporosis risk, promoting timely intervention.

Opportunistic Assessment of Hip Fracture Risk Based on Chest CT

OBJECTIVE

Hip fracture (HF) has been described as the "last fracture of life" in the elderly, so the assessment of HF risk is extremely important. Currently, few studies have examined the relationship between imaging data from chest computed tomography (CT) and HF. This study demonstrated that pectoral muscle index (PMI) and vertebral body attenuation values could predict HF, aiming to opportunistically assess the risk of HF in patients without bone mineral density (BMD) based on chest CT for other diseases.

METHODS

In the retrospective study, 800 participants who had both BMD and chest CT were enrolled from January 2021 to January 2024. After exclusion, 472 patients were finally enrolled, divided into the healthy control (HC) group and the HF group. Clinical data were collected, and differences between the two groups were compared. A predictive model was constructed based on the PMI and CT value of the fourth thoracic vertebra (T4HU) by logistic regression analysis, and the predictive effect of the model was analyzed by using the receiver operating characteristic (ROC) curve. Finally, the clinical utility of the model was analyzed using decision curve analysis (DCA) and clinical impact curves.

RESULTS

Both PMI and T4HU were lower in the HF group than in the HC group (p < 0.05); low PMI and low T4HU were risk factors for HF. The predictive model incorporating PMI and T4HU on the basis of age and BMI had excellent diagnostic efficacy with an area under the curve (AUC) of 0.865 (95% confidence interval [CI]: 0.830-0.894, p < 0.01), sensitivity and specificity of 0.820 and 0.754, respectively. The clinical utility of the model was validated using calibration curves and DCA. The AUC of the predictive model incorporating BMD based on age and BMI was 0.865 (95% CI: 0.831-0.895, p < 0.01), with sensitivity and specificity of 0.698 and 0.711, respectively. There was no significant difference in diagnostic efficacy between the two models (p = 0.967).

CONCLUSIONS

PMI and T4HU are predictors of HF in patients. In the absence of dual-energy x-ray absorptiometry (DXA), the risk of HF can be assessed by measuring the PMI and T4HU on chest CT examination due to other diseases, and further treatment can be provided in time to reduce the incidence of HF.

The relationship of body composition with bone mineral density and 10-year probability of hip fracture in postmenopausal women

INTRODUCTION

Postmenopausal osteoporosis and fractures are widely prevalent. However, the relationship of body composition with bone health in this population remains unclear. The aim of this study was to investigate the association of body composition with bone mineral density (BMD) and 10-year probability of hip fracture in postmenopausal women.

MATERIALS AND METHODS

This is a cross-sectional study. A total of 1285 subjects were included in our study. Body composition and BMD were assessed using dual-energy X-ray densitometry. The 10-year probability of hip fracture of participants was calculated. All participants were categorized into four groups: sarcopenic-obese (SO) group, sarcopenic-nonobese (S) group, nonsarcopenic-obese (O) group, or nonsarcopenic-nonobese control (C) group. Multivariate analyses and binary logistic regression were conducted to explore the relationship of body composition with BMD and 10-year probability of hip fracture.

RESULTS

Participants in S group were 2.8, 4.7 and 4.8 times more likely to develop osteoporosis in the lumbar spine, the total hip and femoral neck sites, respectively. Lean mass was positively correlated with BMD, wherein lumbar spine BMD was significantly affected by appendicular lean mass, while total hip BMD and femoral neck BMD were mainly influenced by trunk lean mass. Total fat mass was positively associated with total hip and femoral neck BMD, but not with lumbar spine BMD. A significant correlation was observed between lean mass and 10-year probability of hip fracture.

CONCLUSION

Changes in body composition in postmenopausal women could affect bone health. A decrease in regional lean mass may be associated with an increased risk of osteoporosis and fractures.

The impact of sarcopenia on the incidence of postoperative outcomes following spine surgery: Systematic review and meta-analysis

PURPOSE

Sarcopenia is considered to be an important predictor of adverse outcomes following spinal surgery, but the specific relationship between the two is not clear. The purpose of this meta-analysis is to systematically review all relevant studies to evaluate the impact of sarcopenia on spinal surgery outcomes.

METHODS

We systematically searched PubMed, Embase and the Cochrane Library for relevant articles published on or before January 9, 2023. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was calculated in a random effects meta-analysis. The main outcome was the risk of adverse outcomes after spinal surgery, including adverse events and mortality. This systematic review and meta-analysis was conducted following the PRISMA guidelines to evaluate the impact of sarcopenia on spinal surgery outcomes. In addition, we also conducted a subgroup analysis and leave-one-out sensitivity analyses to explore the main sources of heterogeneity and the stability of the results.

RESULTS

Twenty-four cohort studies, with a total of 243,453 participants, met the inclusion criteria. The meta-analysis showed that sarcopenia was significantly associated with adverse events (OR 1.63, 95% CI 1.17-2.27, P < 0.001) but was no significantly associated with mortality (OR 1.17, 95% CI 0.93-1.46, P = 0.180), infection (OR 2.24, 95% CI 0.95-5.26, P < 0.001), 30-day reoperation (OR 1.47, 95% CI 0.92-2.36, P = 0.413), deep vein thrombosis (OR 1.78, 95% CI 0.69-4.61, P = 0.234), postoperative home discharge (OR 0.60, 95% CI 0.26-1.37, P = 0.002) and blood transfusion (OR 3.28, 95% CI 0.74-14.64, P = 0.015).

CONCLUSION

The current meta-analysis showed that patients with sarcopenia have an increased risk of adverse events and mortality after spinal surgery. However, these results must be carefully interpreted because the number of studies included is small and the studies are significantly different. These findings may help to increase the clinicians' awareness of the risks concerning patients with sarcopenia to improve their prognosis.

Bone-muscle crosstalk under physiological and pathological conditions

Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system.

A Novel MRI-Based Paravertebral Muscle Quality (PVMQ) Score for Evaluating Muscle Quality and Bone Quality: A Comparative Study with the VBQ Score

Purpose

This study aims to develop a novel MRI-based paravertebral muscle quality (PVMQ) score for assessing muscle quality and to investigate its correlation with the degree of fat infiltration (DFF) and the vertebral bone quality (VBQ) score of paravertebral muscles. Additionally, the study compares the effectiveness of the PVMQ score and the VBQ score in assessing muscle quality and bone quality.

Methods

PVMQ scores were derived from the ratio of paravertebral muscle signal intensity (SI) to L3 cerebrospinal fluid SI on T2-weighted MRI. Image J software assessed paravertebral muscle cross-sectional area (CSA) and DFF. Spearman rank correlation analyses explored associations between PVMQ, VBQ scores, DFF, and T-scores in both genders. Receiver operating characteristic (ROC) curves compared PVMQ and VBQ scores' effectiveness in distinguishing osteopenia/osteoporosis and high paraspinal muscle DFF.

Results

In this study of 144 patients (94 females), PVMQ scores were significantly higher in osteoporosis and osteopenia groups compared to normals, with variations observed between genders (P < 0.05). PVMQ showed stronger positive correlation with VBQ scores and DFF in females than males (0.584 vs 0.445, 0.579 vs 0.528; P < 0.01). ROC analysis favored PVMQ over VBQ for low muscle mass in both genders (AUC = 0.767 vs 0.718, 0.793 vs 0.718). VBQ was better for bone mass in males (0.737/0.865 vs 0.691/0.858), whereas PVMQ excelled for females (0.808/0.764 vs 0.721/0.718).

Conclusion

The novel PVMQ score provides a reliable assessment of paravertebral muscle quality and shows a strong correlation with VBQ scores and DFF, particularly in females. It outperforms VBQ scores in evaluating muscle mass and offers valuable insights for assessing bone mass in females. These findings underscore the potential of the PVMQ score as a dual-purpose tool for evaluating both muscle and bone health, informing future research and clinical practice.

miRNA-seq analysis of high glucose induced osteoblasts provides insight into the mechanism underlying diabetic osteoporosis

The present study aims to explore the etiology of Diabetic osteoporosis (DOP), a chronic complication associated with diabetes mellitus. Specifically, the research seeks to identify potential miRNA biomarkers of DOP and investigated role in regulating osteoblasts. To achieve this, an animal model of DOP was established through the administration of a high-sugar and high-fat diet, and then injection of streptozotocin. Bone microarchitecture and histopathology analysis were analyzed. Rat calvarial osteoblasts (ROBs) were stimulated with high glucose (HG). MiRNA profiles of the stimulated osteoblasts were compared to control osteoblasts using sequencing. Proliferation and mineralization abilities were assessed using MTT assay, alkaline phosphatase, and alizarin red staining. Expression levels of OGN, Runx2, and ALP were determined through qRT-PCR and Western blot. MiRNA-sequencing results revealed increased miRNA-702-5p levels. Luciferase reporter gene was utilized to study the correlation between miR-702-5p and OGN. High glucose impaired cell proliferation and mineralization in vitro by inhibiting OGN, Runx2, and ALP expressions. Interference with miR-702-5p decreased OGN, Runx2, and ALP levels, which were restored by OGN overexpression. Additionally, downregulation of OGN and Runx2 in DOP rat femurs was confirmed. Therefore, the miRNA-702-5p/OGN/Runx2 signaling axis may play a role in DOP, and could be diagnostic biomarker and therapeutic target for not only DOP but also other forms of osteoporosis.

Relationship between muscle and subcutaneous adipose tissue size and density and proximal femur bone in elderly women with hip fracture

BACKGROUND

Both osteoporosis and sarcopenia are associated with aging, increasing the likelihood of falls in older adults and consequently raising the risk of hip fractures (HF).

AIMS

To explore the relationship between the size and density of muscle and subcutaneous adipose tissue (SAT) and the bone mineral density (BMD) of the proximal femur in elderly women with HF.

METHODS

Quantitative computed tomography (QCT) was conducted on the hips of 661 female participants who experienced low-energy acute HFs to measure both areal BMD (aBMD) and volume BMD (vBMD). Measurements were taken for the cross-sectional area (CSA) and density of the muscle around the hip and adjacent SAT. Multivariable linear regression models were applied to assess the relationship between these parameters.

RESULTS

Most increases in the density of the gluteus medius and minimus muscle (G.Med/MinM) were correlated with higher BMD in the femoral neck fracture (FNF) group with osteoporosis. In the FNF group, gluteus maximus muscle (G.MaxM) density was negatively associated with the BMD parameters of the proximal femur in individuals with osteoporosis, while they were positively associated with nonosteoporosis. In the intertrochanteric fracture (ITF) group without osteoporosis, both FN aBMD and FN vBMD showed significant correlations with G.Med/MinM density.

DISCUSSION

In women with HFs, bone and muscle are closely related.

CONCLUSIONS

In older women with HFs, density but not CSA of the G.Med/MinM were associated with BMD parameters of the proximal femur. Osteoporosis may influence the relationship between G.MaxM density and proximal femur BMD in elderly women with FNF.

Vertebral HU value and the pectoral muscle index based on chest CT can be used to opportunistically screen for osteoporosis

BACKGROUND

Existing studies have shown that computed tomography (CT) attenuation and skeletal muscle tissue are strongly associated with osteoporosis; however, few studies have examined whether vertebral HU values and the pectoral muscle index (PMI) measured at the level of the 4th thoracic vertebra (T4) are strongly associated with bone mineral density (BMD). In this study, we demonstrate that vertebral HU values and the PMI based on chest CT can be used to opportunistically screen for osteoporosis and reduce fracture risk through prompt treatment.

METHODS

We retrospectively evaluated 1000 patients who underwent chest CT and DXA scans from August 2020-2022. The T4 HU value and PMI were obtained using manual chest CT measurements. The participants were classified into normal, osteopenia, and osteoporosis groups based on the results of dual-energy X-ray (DXA) absorptiometry. We compared the clinical baseline data, T4 HU value, and PMI between the three groups of patients and analyzed the correlation between the T4 HU value, PMI, and BMD to further evaluate the diagnostic efficacy of the T4 HU value and PMI for patients with low BMD and osteoporosis.

RESULTS

The study ultimately enrolled 469 participants. The T4 HU value and PMI had a high screening capacity for both low BMD and osteoporosis. The combined diagnostic model-incorporating sex, age, BMI, T4 HU value, and PMI-demonstrated the best diagnostic efficacy, with areas under the receiver operating characteristic curve (AUC) of 0.887 and 0.892 for identifying low BMD and osteoporosis, respectively.

CONCLUSIONS

The measurement of T4 HU value and PMI on chest CT can be used as an opportunistic screening tool for osteoporosis with excellent diagnostic efficacy. This approach allows the early prevention of osteoporotic fractures via the timely screening of individuals at high risk of osteoporosis without requiring additional radiation.

Osteocytes/Osteoblasts Produce SAA3 to Regulate Hepatic Metabolism of Cholesterol

Hypercholesterolaemia is a systemic metabolic disease, but the role of organs other than liver in cholesterol metabolism is unappreciated. The phenotypic characterization of the Tsc1Dmp1 mice reveal that genetic depletion of tuberous sclerosis complex 1 (TSC1) in osteocytes/osteoblasts (Dmp1-Cre) triggers progressive increase in serum cholesterol level. The resulting cholesterol metabolic dysregulation is shown to be associated with upregulation and elevation of serum amyloid A3 (SAA3), a lipid metabolism related factor, in the bone and serum respectively. SAA3, elicited from the bone, bound to toll-like receptor 4 (TLR4) on hepatocytes to phosphorylate c-Jun, and caused impeded conversion of cholesterol to bile acids via suppression on cholesterol 7 α-hydroxylase (Cyp7a1) expression. Ablation of Saa3 in Tsc1Dmp1 mice prevented the CYP7A1 reduction in liver and cholesterol elevation in serum. These results expand the understanding of bone function and hepatic regulation of cholesterol metabolism and uncover a potential therapeutic use of pharmacological modulation of SAA3 in hypercholesterolaemia.

Relationship between paraspinal muscle properties and bone mineral density based on QCT in patients with lumbar disc herniation

OBJECTIVE

Increasing research suggests that paraspinal muscle fat infiltration may be a potential biological marker for the assessment of osteoporosis. Our aim was to investigate the relationship between lumbar paraspinal muscle properties on MRI and volumetric bone mineral density (vBMD) based on QCT in patients with lumbar disc herniation (LDH).

METHODS

A total of 383 patients (aged 24-76 years, 193 females) with clinically and radiologically diagnosed LDH were enrolled in this retrospective study. The muscle cross-sectional area (CSA) and the proton density fat fraction (PDFF) were measured for the multifidus (MF), erector spinae (ES) and psoas major (PS) at the central level of L3/4, L4/5 and L5/S1 on lumbar MRI. QCT was used to measure the vBMD of two vertebral bodies at L1 and L2 levels. Patients were divided into three groups based on their vBMD values: normal bone density group (> 120 mg/cm3), osteopenia group (80 to 120 mg/cm3) and osteoporosis group (< 80 mg/cm3). The differences in paraspinal muscle properties among three vBMD groups were tested by one-way ANOVA with post hoc analysis. The relationships between paraspinal muscle properties and vBMD were analyzed using Pearson correlation coefficients. Furthermore, the association between vBMD and paraspinal muscle properties was further evaluated using multiple linear regression analysis, with age and sex also included as predictors.

RESULTS

Among the 383 LDH patients, 191 had normal bone density, 129 had osteopenia and 63 had osteoporosis. In LDH patients, compared to normal and osteopenia group, paraspinal muscle PDFF was significantly greater in osteoporosis group, while paraspinal muscle CSA was lower (p < 0.001). After adjusting for age and sex, it was found that MF PDFF and PS CSA were found to be independent factors influencing vBMD (p < 0.05).

CONCLUSION

In patients with LDH, paraspinal muscle properties measured by IDEAL-IQ sequence and lumbar MR scan were found to be related to vBMD. There was a correlation between the degree of paraspinal muscle PDFF and decreasing vBMD, as well as a decrease paraspinal muscle CSA with decreasing vBMD. These findings suggest that clinical management should consider offering tailored treatment options for patients with LDH based on these associations.

The effects of myosteatosis on skeletal muscle function in older adults

Myosteatosis, or the infiltration of fatty deposits into skeletal muscle, occurs with advancing age and contributes to the health and functional decline of older adults. Myosteatosis and its inflammatory milieu play a larger role in adipose tissue dysfunction, muscle tissue dysfunction, and increased passive muscle stiffness. Combined with the age-related decline of sex hormones and development of anabolic resistance, myosteatosis also contributes to insulin resistance, impaired muscle mechanics, loss of force production from the muscle, and increased risk of chronic disease. Due to its highly inflammatory secretome and the downstream negative effects on muscle metabolism and mechanics, myosteatosis has become an area of interest for aging researchers and clinicians. Thus far, myosteatosis treatments have had limited success, as many lack the potency to completely rescue the metabolic and physical consequences of myosteatosis. Future research is encouraged for the development of reliable assessment methods for myosteatosis, as well as the continued exploration of pharmacological, nutritional, and exercise-related interventions that may lead to the success in attenuating myosteatosis and its clinical consequences within the aging population.

Dexamethasone-induced muscle atrophy and bone loss in six genetically diverse collaborative cross founder strains demonstrates phenotypic variability by Rg3 treatment

Background

Osteosarcopenia is a common condition characterized by the loss of both bone and muscle mass, which can lead to an increased risk of fractures and disability in older adults. The study aimed to elucidate the response of various mouse strains to treatment with Rg3, one of the leading ginsenosides, on musculoskeletal traits and immune function, and their correlation.

Methods

Six Collaborative Cross (CC) founder strains induced muscle atrophy and bone loss with dexamethasone (15 mg/kg) treatment for 1 month, and half of the mice for each strain were orally administered Rg3 (20 mg/kg). Different responses were observed depending on genetic background and Rg3 treatment.

Results

Rg3 significantly increased grip strength, running performance, and expression of muscle and bone health-related genes in a two-way analysis of variance considering the genetic backgrounds and Rg3 treatment. Significant improvements in grip strength, running performance, bone area, and muscle mass, and the increased gene expression were observed in specific strains of PWK/PhJ. For traits related to muscle, bone, and immune functions, significant correlations between traits were confirmed following Rg3 administration compared with control mice. The phenotyping analysis was compiled into a public web resource called Rg3-OsteoSarco.

Conclusion

This highlights the complex interplay between genetic determinants, pathogenesis of muscle atrophy and bone loss, and phytochemical bioactivity and the need to move away from single inbred mouse models to improve their translatability to genetically diverse humans. Rg3-OsteoSarco highlights the use of CC founder strains as a valuable tool in the field of personalized nutrition.

The efficacy of nutritional screening indexes in predicting the incidence of osteosarcopenia and major osteoporotic fracture in the elderly

INTRODUCTION

The effect of nutritional status on osteosarcopenia (OS) and major osteoporotic fracture (MOF) among the elderly is still unclear. So we aimed to compare the efficacy of the Mini-Nutrition Assessment-Short Form (MNA-sf), the Geriatric Nutritional Risk Index (GNRI) and Controlling Nutritional Status (CONUT) for predicting OS and MOF among the elderly.

MATERIALS AND METHODS

A total of 409 participants were enrolled in this prospective study. Blood biochemical indexes, nutritional status, and bone- and muscle-related examinations were assessed at initial visit to the outpatient. Participants were divided into 4 groups: (1) control; (2) osteopenia/osteoporosis; (3) sarcopenia; (4) osteosarcopenia, and then followed for 5 years, recording the occurrence time of MOF.

RESULTS

The frequency values of osteopenia/osteoporosis, sarcopenia, and OS, at baseline, were respectively 13.4, 16.1, and 12% among the study samples. Correlation analysis showed that nutritional status scores were associated with body mass index, handgrip strength, albumin, bone mineral density, and physical functions. According to multivariate models, poor nutritional status was significantly associated with a higher risk of OS and MOF (P < 0.05). Survival analysis showed that the MOF rate in malnutrition group was significantly higher than normal nutrition group (P < 0.05). The receiver operator characteristic curve shows that the value of MNA-sf to diagnose OS and MOF is greater (P < 0.05).

CONCLUSION

The poor nutritional status was associated with a higher risk of both OS and MOF. MNA-sf showed a superior diagnostic power for OS and MOF among the elderly. Early nutrition assessments and interventions may be key strategies to prevent OS and fractures.

Identification of bone mineral density associated genes with shared genetic architectures across multiple tissues: Functional insights for EPDR1, PKDCC, and SPTBN1

Recent studies suggest a shared genetic architecture between muscle and bone, yet the underlying molecular mechanisms remain elusive. This study aims to identify the functionally annotated genes with shared genetic architecture between muscle and bone using the most up-to-date genome-wide association study (GWAS) summary statistics from bone mineral density (BMD) and fracture-related genetic variants. We employed an advanced statistical functional mapping method to investigate shared genetic architecture between muscle and bone, focusing on genes highly expressed in muscle tissue. Our analysis identified three genes, EPDR1, PKDCC, and SPTBN1, which are highly expressed in muscle tissue and previously unlinked to bone metabolism. About 90% and 85% of filtered Single-Nucleotide Polymorphisms were in the intronic and intergenic regions for the threshold at P≤5×10-8 and P≤5×10-100, respectively. EPDR1 was highly expressed in multiple tissues, including muscles, adrenal glands, blood vessels, and the thyroid. SPTBN1 was highly expressed in all 30 tissue types except blood, while PKDCC was highly expressed in all 30 tissue types except the brain, pancreas, and skin. Our study provides a framework for using GWAS findings to highlight functional evidence of crosstalk between multiple tissues based on shared genetic architecture between muscle and bone. Further research should focus on functional validation, multi-omics data integration, gene-environment interactions, and clinical relevance in musculoskeletal disorders.

Hepatocellular carcinoma and musculoskeletal system: A narrative literature review

Musculoskeletal alterations in hepatocellular carcinoma (HCC) are less common than liver-related complications. However, they can significantly impact the quality of life and overall prognosis of patients with HCC. The main obstacle in the clinical assessment of HCC-induced musculoskeletal alterations is related to effective and timely diagnosis because these complications are often asymptomatic and unapparent during routine clinical evaluations. This narrative literature review aimed to provide a comprehensive overview of the contemporary literature related to the changes in the musculoskeletal system in patients with HCC, focusing on its clinical implications and underlying etiopathogenetic mechanisms. Osteolytic bone metastases are the most common skeletal alterations associated with HCC, which could be associated with an increased risk of low-trauma bone fracture. Moreover, previous studies reported that osteopenia, sarcopenia, and myosteatosis are associated with poor clinical outcomes in patients with HCC. Even though low bone mineral density and sarcopenia are consistently reported as reliable predictors of pretransplantation and post-transplantation mortality in HCC patients, these complications are frequently overlooked in the clinical management of patients with HCC. Taken together, contemporary literature suggests that a multidisciplinary approach is essential for early recognition and clinical management of HCC-associated musculoskeletal alterations to improve patient prognosis. Further research into the mechanisms and treatment options for musculoskeletal complications is warranted to enhance our understanding and clinical management of this aspect of HCC.

Hepatocellular carcinoma and musculoskeletal system: A narrative literature review

Musculoskeletal alterations in hepatocellular carcinoma (HCC) are less common than liver-related complications. However, they can significantly impact the quality of life and overall prognosis of patients with HCC. The main obstacle in the clinical assessment of HCC-induced musculoskeletal alterations is related to effective and timely diagnosis because these complications are often asymptomatic and unapparent during routine clinical evaluations. This narrative literature review aimed to provide a comprehensive overview of the contemporary literature related to the changes in the musculoskeletal system in patients with HCC, focusing on its clinical implications and underlying etiopathogenetic mechanisms. Osteolytic bone metastases are the most common skeletal alterations associated with HCC, which could be associated with an increased risk of low-trauma bone fracture. Moreover, previous studies reported that osteopenia, sarcopenia, and myosteatosis are associated with poor clinical outcomes in patients with HCC. Even though low bone mineral density and sarcopenia are consistently reported as reliable predictors of pretransplantation and post-transplantation mortality in HCC patients, these complications are frequently overlooked in the clinical management of patients with HCC. Taken together, contemporary literature suggests that a multidisciplinary approach is essential for early recognition and clinical management of HCC-associated musculoskeletal alterations to improve patient prognosis. Further research into the mechanisms and treatment options for musculoskeletal complications is warranted to enhance our understanding and clinical management of this aspect of HCC.

Effect of sarcopenia on refractures of adjacent vertebra after percutaneous kyphoplasty

PURPOSE

To explore the effect of sarcopenia on recurrent fractures of adjacent vertebra after percutaneous kyphoplasty (PKP).

METHODS

A total of 376 osteoporotic vertebral compression fractures (OVCFs) patients over 55 years old who were admitted to the Hospital from August 2020 to January 2021 were selected. Among them, 38 patients with recurrent fractures in adjacent vertebra after PKP were selected as the refracture group (RG), and the remaining 338 patients were selected as the non-refracture group (NRG). The age, gender, grip strength, body mass index (BMI), bone mineral density (BMD), visual analogue scale (VAS) of pain before and one month after surgery, Oswestry disability index (ODI) before and one month after surgery and the occurrence of sarcopenia were compared between the two groups. Logistic regression analysis was used to evaluate the effect of related risk factors on refracture after vertebral PKP.

RESULTS

The results of t-test and Chi-square test showed that there were no obvious differences in gender, BMI, preoperative VAS score (t=-0.996, P = 0.320) and ODI (t=-0.424, P = 0.671), one month postoperative VAS score (t=-0.934, P = 0.355) and ODI score (t=-0.461, P = 0.645). while the age and grip strength showed significant differences between the two groups. Logistic regression analysis showed that BMI and gender had no significant effect on refracture after PKP, while sarcopenia and advanced age were independent risk factors for refracture after PKP. Also, increased BMD was a protective factor for refracture after PKP.

CONCLUSION

Sarcopenia is an independent risk factor for recurrent fractures after PKP in OVCF patients. The screening and diagnosis of sarcopenia should be strengthened. At the same time, anti-sarcopenia treatment should be actively performed after surgery.

Association Between Advanced Glycation End Products and Sarcopenia: The Mediating Role of Osteoporosis

CONTEXT

Advanced glycation end products (AGEs) are a group of molecules formed through nonenzymatic reactions. These compounds are associated with several age-related diseases, including sarcopenia and osteoporosis.

OBJECTIVE

This work aimed to investigate the relationships between AGEs, osteoporosis, and sarcopenia in community-dwelling older adults.

METHODS

This cross-sectional study included 1991 older adults aged 72.37 ± 5.90 years from China. AGE levels were measured by the AGE Reader device. Bone mineral density was assessed using dual-energy X-ray absorptiometry, and osteoporosis was diagnosed based on a T score of less than -2.5. Sarcopenia was defined as loss of muscle mass plus loss of muscle strength and/or reduced physical performance. Presarcopenia was defined as low muscle mass with normal muscle strength and normal physical performance.

RESULTS

The prevalence of sarcopenia was 18.5%, and that of osteoporosis was 40.5%. Compared to the lowest AGE quartile, the highest AGE quartile showed a significant association with sarcopenia (odds ratio [OR] 2.42; 95% CI, 1.60-3.66) (P for trend <.001), but not with presarcopenia. Per-SD increase in AGE was associated with higher odds of sarcopenia (OR 1.44; 95% CI, 1.26-1.66). Additionally, in the mediation analysis, when AGEs were treated as a continuous variable (the mediation effect is denoted by Za*Zb = 18.81; 95% CI, 8.07-32.32]-the 95% CI does not contain zero, representing a significant mediating effect) or a categorical variable (the mediating effect is expressed as Zmediation = 3.01 > 1.96, which represents a significant mediating effect), osteoporosis played a partial mediating role in the association between AGEs and sarcopenia.

CONCLUSION

Elevated AGEs are associated with sarcopenia but not with presarcopenia. This association was partially mediated by osteoporosis.

17β-Estradiol Effects in Skeletal Muscle: A 31P MR Spectroscopic Imaging (MRSI) Study of Young Females during Early Follicular (EF) and Peri-Ovulation (PO) Phases

The natural variation in estrogen secretion throughout the female menstrual cycle impacts various organs, including estrogen receptor (ER)-expressed skeletal muscle. Many women commonly experience increased fatigue or reduced energy levels in the days leading up to and during menstruation, when blood estrogen levels decline. Yet, it remains unclear whether endogenous 17β-estradiol, a major estrogen component, directly affects the energy metabolism in skeletal muscle due to the intricate and fluctuating nature of female hormones. In this study, we employed 2D 31P FID-MRSI at 7T to investigate phosphoryl metabolites in the soleus muscle of a cohort of young females (average age: 28 ± 6 years, n = 7) during the early follicular (EF) and peri-ovulation (PO) phases, when their blood 17β-estradiol levels differ significantly (EF: 28 ± 18 pg/mL vs. PO: 71 ± 30 pg/mL, p < 0.05), while the levels of other potentially interfering hormones remain relatively invariant. Our findings reveal a reduction in ATP-referenced phosphocreatine (PCr) levels in the EF phase compared to the PO phase for all participants (5.4 ± 4.3%). Furthermore, we observe a linear correlation between muscle PCr levels and blood 17β-estradiol concentrations (r = 0.64, p = 0.014). Conversely, inorganic phosphate Pi and phospholipid metabolite GPC levels remain independent of 17β-estradiol but display a high correlation between the EF and PO phases (p = 0.015 for Pi and p = 0.0008 for GPC). The robust association we have identified between ATP-referenced PCr and 17β-estradiol suggests that 17β-estradiol plays a modulatory role in the energy metabolism of skeletal muscle.

Exercise-induced modulation of myokine irisin on muscle-bone unit in the rat model of post-traumatic osteoarthritis

BACKGROUND AND AIM

Post-traumatic osteoarthritis (PTOA) is a subtype of osteoarthritis (OA). Exercise may produce and release the myokine irisin through muscle fiber contraction. However, the effect of exercise-promoted irisin production on the internal interactions of the muscle-bone unit in PTOA studies remains unclear.

METHODS

Eighteen 8-week-old Sprague-Dawley (SD) rats were randomly divided into three groups: Sham/sedentary (Sham/Sed), PTOA/sedentary (PTOA/Sed), and PTOA/treadmill-walking (PTOA/TW). The PTOA model was established by transection of anterior cruciate ligament (ACLT) and destabilization of medial meniscus (DMM). After 4 weeks of modeling, the PTOA/TW group underwent treadmill exercise (15 m/min, 30 min/d, 5 d/ week, 8 weeks), and the other two groups were free to move in the cage. Evaluation and correlation analysis of muscle, cartilage, subchondral bone and serological indexes were performed after euthanasia.

RESULTS

Eight weeks of treadmill exercise effectively alleviated the trauma-induced OA phenotype, thereby maintaining cartilage and subchondral bone integrity in PTOA, and reducing quadriceps atrophy and myofibril degradation. Exercise reversed the down-regulated expression of peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) and fibronectin type III structural domain protein 5 (FNDC5) in muscle tissue of PTOA rats, and increased the blood irisin level, and the irisin level was positively correlated with the expression of PGC-1α and FNDC5. In addition, correlation analysis showed that irisin metabolism level was strongly negatively correlated with Osteoarthritis Research Society International (OARSI) and subchondral bone loss, indicating that irisin may be involved in cartilage biology and PTOA-related changes in cartilage and subchondral bone. Moreover, the metabolic level of irisin was strongly negatively correlated with muscle fiber cross-sectional area (CSA), Atrogin-1 and muscle ring-finger protein-1(MuRF-1) expression, suggesting that irisin may alleviate muscle atrophy through autocrine action.

CONCLUSION

Treadmill exercise can alleviate the atrophy and degeneration of muscle fibers in PTOA rats, reduce the degradation of muscle fibrin, promote the expression of serum irisin, and alleviate the degeneration of articular cartilage and subchondral bone loss in PTOA rats. These results indicate that treadmill exercise can affect the process of PTOA by promoting the expression of myokine irisin in rat muscle-bone unit.

The Interconnection Between Muscle and Bone: A Common Clinical Management Pathway

Often observed with aging, the loss of skeletal muscle (sarcopenia) and bone (osteoporosis) mass, strength, and quality, is associated with reduced physical function contributing to falls and fractures. Such events can lead to a loss of independence and poorer quality of life. Physical inactivity (mechanical unloading), especially in older adults, has detrimental effects on the mass and quality of bone as well as muscle, while increases in activity (mechanical loading) have positive effects. Emerging evidence suggests that the relationship between bone and muscle is driven, at least in part, by bone-muscle crosstalk. Bone and muscle are closely linked anatomically, mechanically, and biochemically, and both have the capacity to function with paracrine and endocrine-like action. However, the exact mechanisms involved in this crosstalk remain only partially explored. Given older adults with lower bone mass are more likely to present with impaired muscle function, and vice versa, strategies capable of targeting both bone and muscle are critical. Exercise is the primary evidence-based prevention strategy capable of simultaneously improving muscle and bone health. Unfortunately, holistic treatment plans including exercise in conjunction with other allied health services to prevent or treat musculoskeletal disease remain underutilized. With a focus on sarcopenia and osteoporosis, the aim of this review is to (i) briefly describe the mechanical and biochemical interactions between bone and muscle; (ii) provide a summary of therapeutic strategies, specifically exercise, nutrition and pharmacological approaches; and (iii) highlight a holistic clinical pathway for the assessment and management of sarcopenia and osteoporosis.

Therapeutic Effects of Mechanical Stress-Induced C2C12-Derived Exosomes on Glucocorticoid-Induced Osteoporosis Through miR-92a-3p/PTEN/AKT Signaling Pathway

Introduction

Osteoporosis is a common bone disease in which the bone loses density and strength and is prone to fracture. Bone marrow mesenchymal stem cells (BMSCs) are important in bone-related diseases. Exosomes, as mediators of cell communication, have potential in cell processes. Previous studies have focused on muscle factors' regulation of bone remodeling, but research on exosomes is lacking.

Methods

 In order to confirm the therapeutic effect of mechanically stimulated myocytes (C2C12) derived exosomes (Exosome-MS) on the Glucocorticoid-induced osteoporosis(GIOP) compared with unmechanically stimulated myocytes (C2C12) derived exosomes (Exosomes), we established a dexamethasone-induced osteoporosis model in vivo and in vitro. Cell viability and proliferation were assessed using CCK8 and EDU assays. Osteogenic potential was evaluated through Western blotting, real-time PCR, alkaline phosphatase activity assay, and alizarin red staining. Differential expression of miRNAs was determined by high-throughput sequencing. The regulatory mechanism of miR-92a-3p on cell proliferation and osteogenic differentiation via the PTEN/AKT pathway was investigated using real-time PCR, luciferase reporter gene assay, Western blotting, and immunofluorescence. The therapeutic effects of exosomes were evaluated in vivo using microCT, HE staining, Masson staining, and immunohistochemistry.

Results

 In this study, we found that exosomes derived from mechanical stress had a positive impact on the proliferation and differentiation of bone marrow mesenchymal stem cells (BMSCs). Importantly, we demonstrated that miR-92a-3p mimics could reverse dexamethasone-induced osteoporosis in vitro and in vivo, indicating that mechanical stress-induced mouse myoblast-derived exosomes could promote osteogenesis and prevent the occurrence and progression of osteoporosis in mice through miR-92a-3p/PTEN/AKT signaling pathway.

Conclusion

 Exosomes derived from mechanical stress-induced myoblasts can promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells through miR-92a-3p/PTEN/AKT signaling pathway, and can have a therapeutic effect on glucocorticoid-induced osteoporosis in mice in vivo.

Individual and combined associations of sarcopenia, osteoporosis and obesity with frailty in a multi-ethnic asian older adult population

BACKGROUND

We explored the relationships between sarcopenia (SP), osteoporosis (OP), obesity (OB), (alone and in combination) with physical frailty (PF) in a multi-ethnic, population-based study of Asians aged ≥ 60 years.

METHODS

Participants were enrolled from the PopulatION HEalth and Eye Disease PRofile in Elderly Singaporeans Study (PIONEER) study. PF was defined using the modified Fried phenotype; SP using the Asian Working Group for Sarcopenia 2019; OP using bone mineral density scores; and OB using the fat mass index. Modified Poisson regression models investigated the associations between exposures and PF, and the relative excess rates of PF due to interactions (RERI) to determine synergistic or antagonistic interactions.

RESULTS

Of the 2643 participants, 54.8% was female; and 49.8%, 25.1%, 25.0% were Chinese, Indians, and Malays, respectively. 25%, 19.0% and 6.7% participants had OB only, SP only, and OP only, respectively. A total of 356 (17.5%), 151 (7.4%) and 97 (4.8%) had osteosarcopenia (OSP), sarcopenic obesity (SOB) and osteo-obesity (OOB), respectively; while 70 (3.5%) had all 3 morbid conditions (osteosarcopenic obesity, OSO). Both SP only and OB only were strongly associated with increased rates of PF (RR: 2.53, 95% CI: 1.95, 3.29; RR: 2.05, 95% CI: 1.58, 2.66 respectively); but not OP. Those with OSP, OOB and SOB were also associated with high risks of PF (RR: 2.82, 95% CI: 2.16, 3.68; RR: 2.34, 95% CI: 1.69, 3.23; and RR: 2.58, 95% CI: 1.95, 3.41, respectively) compared to robust individuals. Critically, individuals with OSO had the highest relative risk of having PF (RR: 3.06, CI: 2.28, 4.11). Only the sarcopenia-obesity interaction was significant, demonstrating negative synergism (antagonism). The concurrent presence of SP and OB was associated with a 100% lower rate of PF compared to the sum of the relatively rates of SP only and OB only.

CONCLUSION

The prevalence of SP, OB and OP, alone and combined, is substantial in older Asians and their early identification is needed to mitigate the risk of frailty. OB may interact with SP in an antagonistic manner to moderate rates of frailty. Further longitudinal studies are needed to address causality and mechanistic underpinnings our findings.

Copy number variations of LRRFIP1 gene and the relationship with growth traits in four Chinese sheep

CNVs (copy number variations) are the novel and common structural variants that could cover entire genes found in plenty of species. CNV may influence economically important traits or disease susceptibility in livestock species. Based on the whole genome resequencing results, we found that there was a CNV region on the LRRFIP1 gene. Then we used qPCR to detect the copy number type distribution in 553 individuals of four sheep breeds and used them for association analysis. The results showed that: (1) In the CKS, the sheep with gain type had a larger heart girth (p = 0.049). (2) For the HS, the CNV could significantly affect rump breadth (p = 0.037) and circumference of the cannon (p = 0.035). And the sheep with median type showed better performance in rump breadth and circumference of cannon. (3) At the STHS, the CNV was significantly correlated with chest width (p = 0.000) with loss type as the most favorable CNV type. Meanwhile, the best was the loss type, and the lowest was the median. (4) This CNV had no significant effect on the LTHS. So, the CNV of LRRFIP1 was related to the growth traits of these three sheep breeds and it may be used as a molecular marker for sheep.

Muscle-bone crosstalk via endocrine signals and potential targets for osteosarcopenia-related fracture

BACKGROUND

Osteosarcopenia is a syndrome coexisting sarcopenia and osteopenia/osteoporosis, with a high fracture risk. Recently, skeletal muscle and bone have been recognized as endocrine organs capable of communication through secreting myokines and osteokines, respectively. With a deeper understanding of the muscle-bone crosstalk, these endocrine signals exhibit an important role in osteosarcopenia development and fracture healing.

METHODS

This review summarizes the role of myokines and osteokines in the development and treatment of osteosarcopenia and fracture, and discusses their potential for osteosarcopenia-related fracture treatment.

RESULTS

Several well-defined myokines (myostatin and irisin) and osteokines (RANKL and SOST) are found to not only regulate skeletal muscle and bone metabolism but also influence fracture healing processes. Systemic interventions targeting these biochemical signals has shown promising results in improving the mass and functions of skeletal muscle and bone, as well as accelerating fracture healing processes.

CONCLUSION

The regulation of muscle-bone crosstalk via biochemical signals presents a novel and promising strategy for treating osteosarcopenia and fracture by simultaneously enhancing bone and muscle anabolism. We propose that myostatin, irisin, RANKL, and SOST may serve as potential targets to treat fracture patients with osteosarcopenia.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

Osteosarcopenia is an emerging geriatric syndrome where sarcopenia and osteoporosis coexist, with high fracture risk, delayed fracture healing, and increased mortality. However, no pharmacological agent is available to treat fracture patients with osteosarcopenia. This review summarizes the role of several myokines and osteokines in the development and treatment of osteosacropenia and fracture, as well as discusses their potential as intervention targets for osteosarcopenia-related fracture, which provides a novel and promising strategy for future osteosarcopenia-related fracture treatment.

Bidirectional relationship between frailty and cognitive function among Chinese older adults

BACKGROUND

Frailty and cognitive function are two common aging-related conditions among older adults. This study examined the bidirectional relationship between frailty and cognitive function according to sex.

METHODS

All older adults aged ≥65 years who participated in the 2008 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey were included in this study. Binary logistic regression and generalized estimating equation models were used to determine the bidirectional relationship between frailty and cognitive function in cross-sectional and cohort studies, and sex differences were assessed.

RESULTS

We included 12,708 participants who were interviewed in the baseline study. The participants' mean (standard deviation) age was 85.6 (11.1%) years. In the cross-sectional study, the multivariate-adjusted odds ratio (OR; 95% confidence interval [CI]) for pre-frailty and frailty among participants with cognitive impairment was 3.68 (3.29-4.13). Older adults with pre-frailty and frailty had higher risks of cognitive impairment (OR = 3.79, 95% CI: 3.38-4.25). The GEE models showed that pre-frailty and frailty predicted a higher likelihood of cognitive impairment (OR = 2.02, 95% CI, 1.67-2.46) during follow-up. Moreover, the temporal relationship between these relationships differed slightly by sex. Older women with cognitive impairment at baseline were more likely to develop pre-frailty or frailty than did older men.

CONCLUSIONS

This study demonstrated a significant bidirectional relationship between frailty and cognitive function. Moreover, this bidirectional relationship varied by sex. These findings confirm the need to integrate sex-specific interventions for frailty and cognitive functioning problems to improve the quality of life of older adults.

Targeting Kindlin-2 in adipocytes increases bone mass through inhibiting FAS/PPARγ/FABP4 signaling in mice

Osteoporosis (OP) is a systemic skeletal disease that primarily affects the elderly population, which greatly increases the risk of fractures. Here we report that Kindlin-2 expression in adipose tissue increases during aging and high-fat diet fed and is accompanied by decreased bone mass. Kindlin-2 specific deletion (K2KO) controlled by Adipoq-Cre mice or adipose tissue-targeting AAV (AAV-Rec2-CasRx-sgK2) significantly increases bone mass. Mechanistically, Kindlin-2 promotes peroxisome proliferator-activated receptor gamma (PPARγ) activation and downstream fatty acid binding protein 4 (FABP4) expression through stabilizing fatty acid synthase (FAS), and increased FABP4 inhibits insulin expression and decreases bone mass. Kindlin-2 inhibition results in accelerated FAS degradation, decreased PPARγ activation and FABP4 expression, and therefore increased insulin expression and bone mass. Interestingly, we find that FABP4 is increased while insulin is decreased in serum of OP patients. Increased FABP4 expression through PPARγ activation by rosiglitazone reverses the high bone mass phenotype of K2KO mice. Inhibition of FAS by C75 phenocopies the high bone mass phenotype of K2KO mice. Collectively, our study establishes a novel Kindlin-2/FAS/PPARγ/FABP4/insulin axis in adipose tissue modulating bone mass and strongly indicates that FAS and Kindlin-2 are new potential targets and C75 or AAV-Rec2-CasRx-sgK2 treatment are potential strategies for OP treatment.

Anabolic Resistance in the Pathogenesis of Sarcopenia in the Elderly: Role of Nutrition and Exercise in Young and Old People

The development of sarcopenia in the elderly is associated with many potential factors and/or processes that impair the renovation and maintenance of skeletal muscle mass and strength as ageing progresses. Among them, a defect by skeletal muscle to respond to anabolic stimuli is to be considered. Common anabolic stimuli/signals in skeletal muscle are hormones (insulin, growth hormones, IGF-1, androgens, and β-agonists such epinephrine), substrates (amino acids such as protein precursors on top, but also glucose and fat, as source of energy), metabolites (such as β-agonists and HMB), various biochemical/intracellular mediators), physical exercise, neurogenic and immune-modulating factors, etc. Each of them may exhibit a reduced effect upon skeletal muscle in ageing. In this article, we overview the role of anabolic signals on muscle metabolism, as well as currently available evidence of resistance, at the skeletal muscle level, to anabolic factors, from both in vitro and in vivo studies. Some indications on how to augment the effects of anabolic signals on skeletal muscle are provided.

Analysis of the association between osteoporosis and muscle strength in Korean adults: a national cross-sectional study

BACKGROUND

This study aimed to examine the associations between osteoporosis and hand grip strength (HGS), a surrogate marker of muscular strength, among Korean adults stratified by body mass index (BMI), age, and renal function.

METHODS

This study was conducted using the data obtained from the Korea National Health and Nutrition Examination Survey 2015-2019, a cross-sectional and nationally representative survey performed by the Korea Centers for Diseases Control and Prevention.

RESULTS

Of the 26,855 subjects included in this study, those with low muscle strength (LMS) and normal muscle strength were showed in 4,135 (15.4%) and 22,720 (84.6%) subjects, respectively. The osteoporotic subjects had a higher prevalence rate for LMS than those without osteoporosis after adjusting for age [odds ratio (OR), 1.684; 95% confidence interval (CI), 1.500-1.890). The subjects with osteoporosis and BMI < 18.5 kg/m2 also had a higher prevalence rate for LMS after adjusting for age compared to those with non-osteoporosis and BMI < 18.5 kg/m2 (OR, 1.872; 95% CI, 1.043-3.359). Compared to the non-osteoporotic subjects with estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73 m2, those with osteoporosis and eGFR ≥ 60 mL/min/1.73 m2 had a higher prevalence rate for LMS after controlling for age and sex (OR, 1.630; 95% CI, 1.427-1.862).

CONCLUSIONS

The results showed that osteoporosis was likely to contribute to an increased prevalence rate of LMS in terms of HGS. Aging, BMI, and renal function also had significant effects on the association between osteoporosis and LMS. This association is likely to assist in developing better strategies to estimate bone health in clinical or public health practice.

Exploring molecular mechanisms underlying the pathophysiological association between knee osteoarthritis and sarcopenia

Objectives

Accumulating evidence indicates a strong link between knee osteoarthritis (KOA) and sarcopenia. However, the mechanisms involved have not yet been elucidated. This study primarily aims to explore the molecular mechanisms that explain the connection between these 2 disorders.

Methods

The gene expression profiles for KOA and sarcopenia were obtained from the Gene Expression Omnibus database, specifically from GSE55235, GSE169077, and GSE1408. Various bioinformatics techniques were employed to identify and analyze common differentially expressed genes (DEGs) across the 3 datasets. The techniques involved the analysis of Gene Ontology and pathways to enhance understanding, examining protein-protein interaction (PPI) networks, and identifying hub genes. In addition, we constructed the network of interactions between transcription factors (TFs) and genes, the co-regulatory network of TFs and miRNAs for hub genes, and predicted potential drugs.

Results

In total, 14 common DEGs were found between KOA and sarcopenia. Detailed information on biological processes and signaling pathways of common DEGs was obtained through enrichment analysis. After performing PPI network analysis, we discovered 4 hub genes (FOXO3, BCL6, CDKN1A, and CEBPB). Subsequently, we developed coregulatory networks for these hub genes involving TF-gene and TF-miRNA interactions. Finally, we identified 10 potential chemical compounds.

Conclusions

By conducting bioinformatics analysis, our study has successfully identified common gene interaction networks between KOA and sarcopenia. The potential of these findings to offer revolutionary understanding into the common development of these 2 conditions could lead to the identification of valuable targets for therapy.