Anisotropy of Trabecular Bone from Ultra-Distal Radius Digital X-Ray Imaging: Effects on Bone Mineral Density and Age

Background: When applied to trabecular bone X-ray images, the anisotropic properties of trabeculae located at ultra-distal radius were investigated by using the trabecular bone scores (TBS) calculated along directions parallel and perpendicular to the forearm. Methodology: Data from more than two hundred subjects were studied retrospectively. A DXA (GE Lunar Prodigy) scan of the forearm was performed on each subject to measure the bone mineral density (BMD) value at the location of ultra-distal radius, and an X-ray digital image of the same forearm was taken on the same day. The values of trabecular bone score along the direction perpendicular to the forearm, TBSx, and along the direction parallel to the forearm, TBSy, were calculated respectively. The statistics of TBSx and TBSy were calculated, and the anisotropy of the trabecular bone, which was defined as the ratio of TBSy to TBSx and changed with subjects’ BMD and age, was reported and analyzed. Results: The results show that the correlation coefficient between TBSx and TBSy was 0.72 (p BMD and age was reported. The results showed that decreased trabecular bone anisotropy was associated with deceased BMD and increased age in the subject group. Conclusions: This study shows that decreased trabecular bone anisotropy was associated with decreased BMD and increased age.

Age- and direction-related adaptations of lumbar vertebral trabecular bone with respect to apparent stiffness and tissue level stress distribution

The objective of this study was to study the age-related adaptation of lumbar vertebral trabecular bone at the apparent level, as well as the tissue level in three orthogonal directions. Ninety trabecular specimens were obtained from six normal L4 vertebral bodies of six male cadavers in two age groups, three aged 62 years and three aged 69 years, and were scanned using a high-resolution micro-computed tomography （micro-CT） system, then converted to micro- finite element models to do micro-finite element analyses. The relationship between apparent stiffness and bone volume fraction, and the tissue level yon Mises stress distribution for each trabecular specimen when compressed separately in the longitudinal direction, medial-lateral and anterior-posterior directions （transverse directions） were derived and compared between two age groups. The results showed that at the apparent level, trabecular bones from 69-year group had stiffer bone structure relative to their volume fractions in all three directions, and in both age groups, changes in bone volume fraction could explain more variations in apparent stiffness in the longitudinal direction than the transverse directions; at the tissue level, aging had little effect on the tissue von Mises stress distributions for the compressions in all the three directions. The novelty of the present study was that it provided quantitative assessments on the age and direction- related adaptation of Chinese male lumbar vertebral trabecular bone from two different levels： stiffness at the apparent level and stress distribution at the tissue level. It may help to understand the failure mechanisms and fracture risks of vertebral body associated with aging and direction for the prevention of fracture risks in elder individuals.

Experimental repetitive mild traumatic brain injury induces deficits in trabecular bone microarchitecture and strength in mice

To evaluate the long-term consequence of repetitive mild traumatic brain injury （mTBI） on bone, mTBI was induced in 10-week-old female C57BL/6J mice using a weight drop model, once per day for 4 consecutive days at different drop heights （0.5, 1 and 1.5 m） and the skeletal phenotype was evaluated at different time points after the impact. In vivo micro-CT （μ-CT） analysis of the tibial metaphysis at 2, 8 and 12 weeks after the impact revealed a 5%-32% reduction in trabecular bone mass. Histomorphometric analyses showed a reduced bone formation rate in the secondary spongiosa ofl.5 m impacted mice at 12 weeks post impact. Apparent modulus （bone strength）, was reduced by 30% （P 〈 0.05） at the proximal tibial metaphysis in the 1.5 m drop height group at 2 and 8 weeks post impact. Ex vivo μ-CT analysis of the fifth lumbar vertebra revealed a significant reduction in trabecular bone mass at 12 weeks of age in all three drop height groups. Serum levels of osteocalcin were decreased by 22%, 15%, and 19% in the 0.5, 1.0 and 1.5 m drop height groups, respectively, at 2 weeks post impact. Serum IGF-I levels were reduced by 18%-32% in mTBI mice compared to control mice at 2 weeks post impact. Serum osteocalcin and IGF-I levels correlated with trabecular BV/TV （r2 = 0.14 and 0.16, P 〈 0.05）. In conclusion, repetitive mTBI exerts significant negative effects on the trabecular bone microarchitecture and bone mechanical properties by influencing osteoblast function via reduced endocrine IGF-I actions.

Numerical simulation on the adaptation of forms in trabecular bone to mechanical disuse and basic multi-cellular unit activation threshold at menopause

The objective of this paper is to identify the effects of mechanical disuse and basic multi-cellular unit （BMU） activation threshold on the form of trabecular bone during menopause. A bone adaptation model with mechanical- biological factors at BMU level was integrated with finite element analysis to simulate the changes of trabecular bone structure during menopause. Mechanical disuse and changes in the BMU activation threshold were applied to the model for the period from 4 years before to 4 years after menopause. The changes in bone volume fraction, trabecular thickness and fractal dimension of the trabecular structures were used to quantify the changes of trabecular bone in three different cases associated with mechanical disuse and BMU activation threshold. It was found that the changes in the simulated bone volume fraction were highly correlated and consistent with clinical data, and that the trabecular thickness reduced signi-ficantly during menopause and was highly linearly correlated with the bone volume fraction, and that the change trend of fractal dimension of the simulated trabecular structure was in correspondence with clinical observations. The numerical simulation in this paper may help to better understand the relationship between the bone morphology and the mecha-nical, as well as biological environment; and can provide a quantitative computational model and methodology for the numerical simulation of the bone structural morphological changes caused by the mechanical environment, and/or the biological environment.

Microstructure-based Finite Element Modelling and Characterisation of Bovine Trabecular Bone

The mechanical behaviour of trabecular bone is dependent on both the properties of individual trabeculae as well as their three-dimensional arrangement in space. In this study, nanoindentation was used to determine trabecular stiffness of bovine bone, both dehydrated and rehydrated. Values of 18.3 GPa and 14.3 GPa were obtained for dehydrated and rehydrated trabeculae respectively. These values were then used for finite element analysis where the mesh was generated directly from an X-ray microtomography dataset. The relationship between intrinsic tissue properties and apparent stiffness was explored. Moreover, the important role of collagen in bone micromechanics was demonstrated by complementing the study with Raman spectroscopy.

Osteoporosis Prediction for Trabecular Bone using Machine Learning: A Review

Trabecular bone holds the utmost importance due to its significance regarding early bone loss.Diseases like osteoporosis greatly affect the structure of the Trabecular bone which results in different outcomes like high risk of fracture.The objective of this paper is to inspect the characteristics of the Trabecular Bone by using the Magnetic Resonance Imaging(MRI)technique.These characteristics prove to be quite helpful in studying different studies related to Trabecular bone such as osteoporosis.The things that were considered before the selection of the articles for the systematic review were language,research field,and electronic sources.Only those articles written in the English language were selected as it is the most prominent language used in scientific,engineering,computer science,and biomedical researches.This literature review was conducted on the articles published between 2006 and 2020.A total of 62 research papers out of 1050 papers were extracted which were according to our topic of review after screening abstract and article content for the title and abstract screening.The findings from those researches were compiled at the end of the result section.This systematic literature review presents a comprehensive report on scientific researches and studies that have been done in the medical area concerning trabecular bone.

Factors associated with trabecular bone score in postmenopausal women with type 2 diabetes and normal bone mineral density

BACKGROUND Osteoporosis and type 2 diabetes(T2D)have been recognized as a widespread comorbidity leading to excess mortality and an enormous healthcare burden.In T2D,bone mineral density(BMD)may underestimate the risk of low-energy fractures as bone quality is reduced.It was hypothesized that a decrease in the trabecular bone score(TBS),a parameter assessing bone microarchitecture,may be an early marker of impaired bone health in women with T2D.AIM To identify clinical and body composition parameters that affect TBS in postmenopausal women with T2D and normal BMD.METHODS A non-interventional cross-sectional comparative study was conducted.Potentially eligible subjects were screened at tertiary referral center.Postmenopausal women with T2D,aged 50-75 years,with no established risk factors for secondary osteoporosis,were included.BMD,TBS and body composition parameters were assessed by dual-energy X-ray absorptiometry.In women with normal BMD,a wide range of anthropometric,general and diabetes-related clinical and laboratory parameters were evaluated as risk factors for TBS decrease using univariate and multivariate regression analysis and analysis of receiver operating characteristic(ROC)curves.RESULTS Three hundred twelve women were initially screened,176 of them met the inclusion criteria and underwent dual X-ray absorptiometry.Those with reduced BMD were subsequently excluded;96 women with normal BMD were included in final analysis.Among them,43 women(44.8%)showed decreased TBS values(≤1.31).Women with TBS≤1.31 were taller and had a lower body mass index(BMI)when compared to those with normal TBS(Р=0.008 and P=0.007 respectively).No significant differences in HbA1c,renal function,calcium,phosphorus,alkaline phosphatase,PTH and 25(ОН)D levels were found.In a model of multivariate linear regression analysis,TBS was positively associated with gynoid fat mass,whereas the height and androgen fat mass were associated negatively(all P<0.001).In a multiple logistic regression,TBS≤1.31 was associated with lower gynoid fat mass(adjusted odd ratio[OR],0.9,95%confidence interval[CI],0.85-0.94,P<0.001),higher android fat mass(adjusted OR,1.13,95%CI,1.03-1.24,P=0.008)and height(adjusted OR,1.13,95%CI,1.05-1.20,P<0.001).In ROC-curve analysis,height≥162.5 cm(P=0.04),body mass index≤33.85 kg/m2(P=0.002),gynoid fat mass≤5.41 kg(P=0.03)and android/gynoid fat mass ratio≥1.145(P<0.001)were identified as the risk factors for TBS reduction.CONCLUSION In postmenopausal women with T2D and normal BMD,greater height and central adiposity are associated with impaired bone microarchitecture.

Imaging Analysis of Trabecular Bone Texture Based on the Initial Slope of Variogram of Ultra-Distal Radius Digital X-Ray Imaging: Effects on Bone Mineral Density and Age

Background: When applied to trabecular bone X-ray images, a method for analyzing trabecular bone texture based on the initial slope of variogram (ISV) was used to assess the trabecular bone health. Methodology: Data from more than two hundred subjects were retrospectively studied. For each subject, a DXA (GE Lunar Prodigy) scan of the forearm was performed, and bone mineral density (BMD) value was measured at the location of ultra-distal radius, X-ray digital image of the same forearm was taken on the same day, and ISV value over the same location of ultra-distal radius was calculated. Pearson’s correlation coefficients were calculated to examine the correlation between BMD and ISV of the trabecular bones located at the same ultra-distal radius. ISV values changed with subjects’ age were also reported. Results: The results show that ISV value was highly correlated with the DXA-measured BMD of the same trabecular bone located at the ultra-distal radius. The correlation coefficient between ISV and BMD with the 95% confident was 0.79 ± 0.09. They also demonstrated that the age-related changes in trabecular bone health and differentiated age patterns in males and females, respectively. The results showed that the decrease in BMD was accompanied by a decrease in the initial slope of variogram (ISV). Conclusions: This study suggests that ISV might be used to quantitatively evaluate trabecular health for osteoporosis and bone disease diagnosis.

Micro-computed tomography assessment of human femoral trabecular bone for two disease groups(fragility fracture and coxarthrosis):Age and gender related effects on the microstructure

The aim of this study was to identify three-dimensional microstructural changes of trabecular bone with age and gender, using micro-computed tomography. Human trabecular bone from two disease groups, osteoporosis and osteoarthritis was analyzed. A prior analysis of the effects of some procedure variables on the micro-CT results was performed. Preliminary micro-CT scans were performed with three voxel resolutions and two acquisition conditions. On the reconstruction step, the image segmentation was performed with three different threshold values. Samples were collected from patients, with coxarthrosis (osteoarthritis) or fragility fracture (osteoporosis). The specimens of the coxarthrosis group include twenty females and fifteen males, while the fragility fracture group was composed by twenty three females and seven males. The mean age of the population was 69 ± 11 (females) and 67 ± 10 years (males), in the coxarthrosis group, while in the fragility fracture group was 81 ± 6 (females) and 78 ± 6 (males) years. The 30 μm voxel size provided lower percentage difference for the microarchitecture parameters. Acquisition conditions with 160 μA and 60 kV permit the evaluation of all the volume’s sample, with low average values of the coefficients of variation of the microstructural parameters. No statistically significant differences were found between the two diseases groups, neither between genders. However, with aging, there is a decrease of bone volume fraction, trabecular number and fractal dimension, and an increase of structural model index and trabecular separation, for both disease groups and genders. The parameters bone specific surface, trabecular thickness and degree of anisotropy have different behaviors with age, depending on the type of disease. While in coxarthrosis patients, trabecular thickness increases with age, in the fragility fracture group, there is a decrease of trabecular thickness with increasing age. Our findings indicate that disease, age and gender do not provide significant differences in trabecular microstructure. With aging, some parameters exhibit different trends which are possibly related to different mechanisms for different diseases.

Effects of Electromagnetic Pulse on Bone Metabolism of Mice in vivo

Objective To study the effects of electromagnetic pulse （EMP） on bone metabolism of mice in vivo. Methods Twenty-four male BALB/c mice were divided into a control group and 2 experimental groups （n=8）. The whole-body of mice in experimental groups were exposed to 50 kV/m and 400kV/m EMP, 400 pulses daily for 7 consecutive days at 2 seconds intervals. Alkaline phosphotase （ALP） activity, serum calcium concentration and osteocalcin level and trabecular bone volume （BV/TV, %） were measured immediately after EMP exposure by biochemical, ELISA and morphological methods. Results The ALP activity, serum calcium concentration and osteocalcin level and BV/TV in experimental groups remained unchanged after EMP exposure. Conelusion Under our experimental conditions, EMP exposure cannot affect bone metabolism of mice in vivo.

Understanding Osteoporosis: Pathophysiology, Risk Factors, Diagnosis, and Management

Osteoporosis is a systemic skeletal disease characterized by low bone mineral density (BMD) and deterioration of bone architecture, resulting in reduced bone strength and, consequently, increased susceptibility to fractures which poses a significant public health concern worldwide, particularly in aging populations [1]. The health-economic impact of vertebral and hip fractures has been extensively explored and it is well known that these fractures are associated with morbidity/disability and increased mortality;they also account for a substantial portion of the direct fracture costs. This review aims to provide a comprehensive overview of osteoporosis, including its pathophysiology, risk factors, diagnostic approaches, and management strategies. By elucidating the multifaceted nature of this condition, healthcare providers can better identify individuals at risk, implement preventive measures, and optimize treatment to reduce the burden of osteoporotic fractures.

Convenient model of hard tissue simulation for dental radiographic research and instruction

BACKGROUND The authors describe a technique for building an alternative jawbone phantom using dental gypsum and rice for research and dental radiology instruction.AIM To investigate the potential of an alternative phantom to simulate the trabecular bone aspect of the human maxilla in periapical radiographs.METHODS Half-maxillary phantoms built from gypsum-ground rice were exposed to X-rays,and the resulting images(experimental group)were compared to standardized radiographic images produced from dry human maxillary bone(control group)(n=7).The images were blindly assessed according to strict criteria by three examiners for the usual trabecular aspects of the surrounding bone,and significant differences between groups and in assessment reliability were compared using Fisher’s exact and kappa tests(α=0.05).RESULTS The differences in the trabecular aspects between groups were not statistically significant.In addition,interobserver agreement among observers was 0.43 and 0.51 for the control and experimental groups,respectively,whereas intraobserver agreement was 0.71 and 0.73,respectively.CONCLUSION The tested phantom seemed to demonstrate potential for trabecular bone image Munhoz EA et al.Model of hard tissue simulation for dental radiography WJM https://www.wjgnet.com 2 March 20,2024 Volume 14 Issue 1 simulation on maxillary periapical radiographs.

Characteristics of Rat Lumbar Vertebral Body Bone Mineral Density and Differential Segmental Responses to Sex Hormone Deficiency:a Clinical Multidetector Computed Tomography Study

Objective To investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. Methods Orchiectomized and ovariectomized rat models are used to investigate sex hormone deficiency related osteoporosis and efficacy of different therapies. A rat vertebral body can be longitudinally divided into central portion, which contain more trabecular bone, and para-endplate portions which contain more compact bone. In matured male and female Wistar and Sprague-Dawley rat lumbar spines, we investigated baseline bone mineral density （BMD） characteristics and the differential segmental responses in bone loss within the lumbar vertebral body post gonadal surgery with clinical multidetector computed tomography. Results Para-endplate sections had a higher BMD than central sections. The cephalad para-endplate sections had a higher BMD than the caudad para-endplate sections. Eight weeks after gonadal removal, there was more bone loss in central sections than para-endplate sections. The relative difference of bone loss between para-endplate and central sections was more apparent in male rats than in female rats. There was more bone loss in caudad sections than cephalad sections; this lead to a further increase of BMD difference between caudad para-endplate sections and cephalad para-endplate sections post gonadal surgery. Conclusion The approach described in this study provided a consistent way to study BMD change within predominantly compact bone portion and trabecular bone portion of the vertebral body.

Evaluation of damage to trabecular bone of the osteoporotic human acetabulum at small strains using nonlinear micro-finite element analyses

Background With advance of age, alterations in bone quality, quantity and microarchitecture render osteoporotic trabecular bone become more sensitive to local failure. The aims of the present study were to clarify the extent to which the distribution of tissue-level stresses and strains was affected by structural changes and the extent to which osteoporotic acetabular trabecular bone was damaged at small strains. Methods Using a DAWING 4000A supercomputer, nonlinear micro-finite element （μFE） analyses were performed to calculate the tissue-level strains and stresses for each element in the trabecular bone of one osteoporotic acetabulum at small strains to quantify the tissue-level damage accumulation and mechanical properties. Results In contour plots of the tissue, maximum principal logarithmic strains, high tissue-level strains, both compressive and tensile, were observed in the osteoporotic trabecular bone at small apparent strains from 0.2% to 0.5% strain. The compressive apparent stress-strain curve showed typical nonlinear behavior and tangent modulus reduction with increasing strains. The microdamage curve suggested that microdamage began at 0.2% apparent strain in the osteoporotic trabecular bone and increased sharply, although very few microfractures occurred. The quartiles of the maximum principal logarithmic strains, minimum principal logarithmic strains and Von Mises stresses increased nonlinearly. For the inter-quartile range of the Von Mises stresses, a leap occurred at small strains ranging from 0.2% to 0.3% while microdamage commenced. Conclusions Extensive microdamage was primarily responsible for the large loss in apparent mechanical properties that occurred in the trabecular bone of the osteoporotic acetabulum at small strains. With increasing apparent strains, continuous nonlinear increments of tissue-level strains and stresses resulted in microdamage that propagated throughout the specimen with very few microfractures. Chin Med J 2009; 122（17）：2041-204 7

Tissue level microstructure and mechanical properties of the femoral head in the proximal femur of fracture patients

This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.

Effect of trabecular bone material properties on ultrasonic backscattering signals

In this study, ultrasonic backscattering signals in cancellous bones were obtained by finite difference time domain （FDTD） simulations, and the effect of trabecular material properties on these signals was analyzed. The backscatter coefficient （BSC） and integrated backscatter coefficient （IBC） were numerically investigated for varying trabecular bone material properties, including density, Lame coefficients, viscosities, and resistance coefficients. The results show that the BSC is a complex function of trabecular bone density, and the IBC increases as density increases. The BSC and IBC increase with the first and second Lame coefficients. While not very sensitive to the second viscosity of the trabeculae, the BSC and IBC decrease as the first viscosity and resistance coefficients increase. The results demonstrate that, in addition to bone mineral density （BMD） and microarchitecture, trabecular material properties significantly influence ultrasonic backseattering signals in cancellous bones. This research furthers the understanding of ultrasonic backscattering in cancellous bones and the characterization of cancellous bone status.

Is there higher percentage of undetected osteopenia and osteoporosis among patients with ulcerative colitis in Saudi Arabia?

Detection of prevalence and development of osteopenia or osteoporosis in patients with inflammatory bowel disease using only bone mineral density could be inappropriate to detect all individuals at risk for osteoporosis.Numerous patients could remain undetected by using only bone mineral density as a screening method,especially in patients with ulcerative colitis.Therefore,trabecular bone score should be used as a complementary method.

Microstructure Study of Normal Lunates with Micro-computed Tomography

In order to study the microstructure characteristics of normal lunate bones, eight fresh cadaver normal lunates were scanned with micro-computed tomography. High-resolution images of the micro-structure of normal lunates were obtained and we analyzed the nutrient foramina. Then nine regions of interest(ROI) were chosen in the central sagittal plane so that we could obtain the parameters of trabecular bones of ROIs. The distal lamellar-like compact structure had statistically significant differences when it was compared with the ROIs in the volar and dorsal ends of the distal cortex. The difference of diameter between the volar and dorsal foramina was significant(P<0.05). However, there was no significant difference regarding the number. The trabecular bones of the volar and dorsal distal ends had lower intensity than those of the distal central subchondral bone plate. The diameters of the nutrient foramina on the volar cortex were larger than those on the dorsal. This research provided more detailed information about microstructure of normal lunate and the nutrient foramina on cortex, and a reference for further study about diseased lunate.

Effects of tissue heterogeneity on trabecular micromechanics examined by microCT-based finite element analysis and digital volume correlation

Trabecular bone is natural material with heterogeneous tissue properties.The effect of tissue heterogeneity on the micromechanical behavior of trabecular bone is commonly evaluated by microCT-based finite element(microFE)analysis.Results from prior work remain inconclusive and lack of experimental validation.To address these issues,we combined microFE analysis with mechanical testing and microCT-based digital volume correlation(DVC),as a validation for the microFE approach.Porcine trabecular specimens were tested in compression as sequential microCT scans were taken.DVC was performed to extract“realistic”boundary conditions that were applied to microFE models,and to measure microstructural deformation and strain of the trabecular specimens.Heterogeneous and homogeneous microFE models of each trabecular specimen were created and compared with the experimentally measured microstructural displacement and strains.Results showed strong correlations between DVC-measured and microFE-predicted trabecular displacement and strain fields(R^(2)>0.9,p<0.05),regardless of heterogeneous or homogeneous material assignments.The heterogeneous and homogeneous models predicted similar magnitudes for maximum or minimum principal strains(R^(2)=1,p<0.05).However,incorporation of tissue heterogeneity decreased more than 16.5%in the overall stress level of the trabecular tissues.Regardless,very strong correlations were found between the heterogeneous and homogeneous model-predicted principal strains or stresses.These results together suggest that tissue heterogeneity may have little effect on microFE modeling of typical elastic displacement and strains in the trabecular bone,suggesting that homogeneous material models might be sufficient to predict general trabecular micromechanics.

Synergistic effects of magnesium ions and simvastatin on attenuation of high-fat diet-induced bone loss

Introduction:Magnesium(Mg)has a prophylactic potential against the onset of hyperlipidemia.Similar to statin,Mg is recommended as lipid-lowering medication for hypercholesterolemia and concomitantly exhibits an association with increased bone mass.The combination of statin with Mg ions(Mg^(2+))may be able to alleviate the high-fat diet(HFD)-induced bone loss and reduce the side-effects of statin.This study aimed to explore the feasibility of combined Mg^(2+)with simvastatin(SIM)for treating HFD-induced bone loss in mice and the involving mechanisms.Materials and methods:C57BL/6 male mice were fed with a HFD or a normal-fat diet(NFD).Mice were intraperitoneally injected SIM and/or orally received water with additional Mg^(2+)until sacrificed.Enzyme-linked immunosorbent assay was performed to measure cytokines and cholesterol in serum and liver lysates.Bone mineral density(BMD)and microarchitecture were assessed by micro-computed tomography(μCT)in different groups.The adipogenesis in palmitate pre-treated HepG2 cells was performed under various treatments.Results:μCT analysis showed that the trabecular bone mass was significantly lower in the HFD-fed group than that in NFD-fed group since week 8.The cortical thickness in HFD-fed group had a significant decrease at week 24,as compared with NFD-fed group.The combination of Mg^(2+)and SIM significantly attenuated the trabecular bone loss in HFD-fed mice via arresting the osteoclast formation and bone resorption.Besides,such combination also reduced the hepatocytic synthesis of cholesterol and inhibited matrix metallopeptidase 13(Mmp13)mRNA expression in pre-osteoclasts.Conclusions:The combination of Mg^(2+)and SIM shows a synergistic effect on attenuating the HFD-induced bone loss.Our current formulation may be a cost-effective alternative treatment to be indicated for obesity-related bone loss.