BMD at multiple sites and risk of fracture of multiple types: long-term results from the Study of Osteoporotic Fractures

DXA-based 3D finite element models predict hip fractures better than areal BMD in elderly women

Bone strength is a major contributor to fracture risk. Areal bone mineral density (aBMD) obtained from dual-energy X-ray absorptiometry (DXA) is used as a surrogate for bone strength in fracture risk prediction. 3D finite element (FE) models predict bone strength better than aBMD but need 3D computed tomography and are not automated. We have earlier developed a method to automatically reconstruct the 3D hip anatomy from a 2D hip DXA image, followed by subject-specific FE-based prediction of proximal femoral strength. In this study, we evaluate the method's ability to predict incident hip fractures in a population-based cohort of women (OSTPRE). We used a sub-cohort including 46 cases with a hip fracture (<10 years from DXA scan) and 2 healthy controls to each hip fracture case, matched by age, height, and body mass index. We automatically reconstructed the 3D hip anatomy and predicted proximal femoral strength using FE analysis for all the subjects of the sub-cohort. The FE-predicted proximal femoral strength was a significantly better predictor of incident hip fractures than aBMD (difference in area under the receiver operating characteristics curve, ΔAUROC = 0.10). This is the first time that 3D FE models obtained from a 2D hip DXA scan outperform aBMD in predicting incident hip fractures in a population-based prospectively followed cohort of women. Our approach provided an improved fracture risk prediction in a clinically feasible manner (only one single DXA image is needed) and without additional costs compared to the current clinical approach.

Comparison of the time-dependent discriminatory accuracy of femoral strength and bone mineral density for predicting future hip and major osteoporotic fractures: a 16-year follow-up of the AGES-Reykjavik cohort

The discriminative accuracy of femoral strength was significantly higher than that of aBMD over 16 years of follow-up for classifying hip fractures and major osteoporotic fractures. The use of accurate thresholds, whether for aBMD or other imaging-based biomarkers, is crucial to improve sensitivity and identify high-risk older adults.

BACKGROUND

Areal bone mineral density (aBMD) is a surrogate for bone strength but has limited prognostic value. Finite element (FE)-derived femoral strength offers a biomechanical alternative to aBMD for fracture risk assessment, but its long-term predictive value remains unclear. This study compared the discriminatory accuracy of aBMD and femoral strength for hip (HFs) and major osteoporotic fractures (MOFs) over 16 years, accounting for mortality risk.

METHODS

In the prospective Age Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) Study, elderly participants underwent CT scans at entry and automated algorithms were used to compute aBMD and femoral strength. Time-dependent area under the receiver operating characteristic curves (AUC) was used to compare the predictive abilities of aBMD and femoral strength. Optimal cutoffs at the Youden's index were compared with the World Health Organization (WHO)-defined aBMD cutoffs at various time points.

RESULTS

The cohort comprised 4621 older adults (mean age 76 ± 5 years). Femoral strength had a significantly higher AUC than aBMD in identifying HFs (p < 0.05) from the 6th year in males and females, while their AUCs in predicting MOFs were similar. WHO-defined aBMD showed low sensitivity (17-52%) but high specificity (78-94%) for both HFs and MOFs. The sensitivity of optimal femoral strength was significantly higher than that of aBMD at comparable specificity by 5-19% for HFs and 2-10% for MOFs (p < 0.05).

CONCLUSIONS

Both image-based markers predict long-term fracture risk and enable opportunistic screening with existing CT scans. However, femoral strength demonstrates better discriminatory accuracy than aBMD. The low sensitivity of the WHO-defined aBMD demonstrates the necessity to revise current risk assessment criteria.

Concentration and genetic regulation of sex hormone binding globulin and fracture risk in older women

OBJECTIVE

This study aimed to examine the association between concentrations of sex hormone binding globulin (SHBG) and fracture risk in community-dwelling older women and explore whether this was explained by the genetic regulation of SHBG.

METHODS

This prospective cohort study examined 4871 women aged ≥70 years who were not taking medications influencing SHBG concentrations. A genome-wide association study was undertaken to identify single nucleotide polymorphisms (SNPs) associated with SHBG concentrations. Incident fracture was confirmed by medical imaging and adjudicated by expert review committee.

RESULTS

The median age of participants was 74.0 years. Over 3.9 (standard deviation 1.4) years of follow-up, 484 participants had an incident fracture. There was a linear trend for a positive association between SHBG concentrations and fracture risk (p = 0.001), with the highest SHBG quartile associated with a significantly greater fracture risk compared with the lowest quartile (hazard ratio 1.54, 95% confidence interval 1.16-2.04, p = 0.003), adjusting for age, body mass index, alcohol consumption, smoking, diabetes, impaired renal function, treatment allocation, medications affecting bone and high-density lipoprotein cholesterol. Two independent SNPs were associated with SHBG concentrations, rs10822163 and rs727428, but neither was associated with fracture risk.

CONCLUSION

SHBG concentrations were positively associated with a greater fracture risk in community-dwelling women aged ≥70 years, which was not explained by genetic variants associated with SHBG regulation.

Advancing HR-pQCT-based homogenised FE models with smooth structured hexahedral meshes

Nonlinear homogenised finite element (hFE) models can accurately predict stiffness and strength of ultra-distal sections of the radius and tibia using in vivo HR-pQCT images. Recent findings showed good stiffness prediction at these distal sections but a limited ability to reproduce experimental strain localisation. The coarseness of voxel-based meshes reduces the computational effort at the cost of heavily simplifying the underlying geometry of the cortex, the gradient of material properties, and the resulting strain distribution. To overcome these limitations, we present a comprehensive approach to generating fully automated, smooth, and structured hexahedral meshes for HR-pQCT scans at the distal radius and tibia. This study used three datasets to validate the proposed hFE pipeline and its short-term repeatability: ex vivo 2nd generation HR-pQCT images of 21 human radii and 25 human tibiae, and 208 in vivo images from same-day repeated scans on 39 individuals. Results show high accuracy in predicting stiffness (tibia: R2=0.94, radius: R2=0.88) and yield force (tibia: R2=0.93, radius: R2=0.95). Mesh sensitivity analysis reveals stabilisation within a ± 3 % error margin. Dice similarity coefficients between mesh and scanned image were >0.98, and good element quality was achieved across the validation datasets (tibia: S-ICNavg=0.809, radius: S-ICNavg=0.764). Along with the improved volumetric representation of distal cortical and trabecular bone geometry and the good element quality, the new pipeline shows gains in computational performance: 11.70±1.49 min for triple-stack tibia images and 11.00±0.97 min for double-stack radius images, respectively. Generating structured meshes with consistent element-to-element correspondence facilitates seamless comparison between patient models or in longitudinal settings, providing an additional clinical information.

Association between the Triglyceride-glucose index and fragility fractures among US adults: insights from NHANES

BACKGROUND

The triglyceride-glucose (TyG) index, a recognized marker for insulin resistance, holds potential implications for skeletal health. However, its relationship with fragility fractures remains uncertain. We aimed to elucidate the association between the TyG index and fragility fractures in the general US population.

METHODS

Cross-sectional data of 25,082 participants were obtained from the National Health and Nutrition Examination Survey. The association between the TyG index and fragility fractures was investigated using univariate and weighted multivariate logistic regression as well as restricted cubic spline (RCS) regression models. The least absolute shrinkage and selection operator regression with ten-fold cross-validation was employed to identify key variables, leading to the development of a nomogram model. Calibration and receiver operating characteristic curves were utilized to evaluate the model's validity.

RESULTS

The overall prevalence of fragility fractures among participants was 1.10%. After adjusting for confounders, the TyG index exhibited a robust association with the risk of fragility fractures (odds ratio, 1.94; 95% confidence interval, 1.31-2.88; P < 0.001). RCS regression demonstrated a positive linear relationship between the TyG index and fragility fractures. The predictive nomogram, incorporating the TyG index and other clinical factors, demonstrated favorable predictive performance (consistency index = 0.901).

CONCLUSIONS

Elevated TyG index levels were significantly correlated with the risk of fragility fractures in the general US population. These findings suggest that the TyG index may serve as a predictive marker for fragility fractures, underscoring the importance of early intervention and improved fracture risk assessment tools in clinical practice.

Association between plain water intake and the risk of osteoporosis among middle-aged and elderly people in the United States: a cross-sectional study

Background

The connection between plain water intake (PWI) and osteoporosis risk is still unclear. The investigation aimed to identify the relationship between PWI and osteoporosis risk in middle-aged and elderly individuals in the United States (US).

Methods

This cross-sectional study was conducted among participants aged 50 years and older in the following waves of the National Health and Nutrition Examination Survey (NHANES): 2007-2008, 2009-2010, 2013-2014, and 2017-2018. The relationship between PWI and osteoporosis risk was examined by multivariable logistic regression models, accompanied by subgroup analyses and interaction tests. Smooth curve fitting and threshold effect analysis were utilized.

Results

The present investigation included 6,686 participants. In accordance with the fully adjusted model, individuals in the highest PWI tertile had a significantly reduced risk of osteoporosis in contrast to those in the lowest tertile [odds ratio (OR) = 0.62; 95% confidence interval (CI): 0.49-0.77; P for trend<0.001]. After adjusting for all covariates, a higher PWI was linked to a decreased risk of osteoporosis (OR = 0.92; 95% CI: 0.86-0.98; p = 0.008). No significant interactions were detected in the subgroup analyses for age, gender, race, body mass index, diabetic history, hypertension status, smoking history, consumption of prednisone or cortisone, or moderate or strenuous activity (all P for interaction>0.05). Smooth curve fitting and threshold effect analysis revealed that when PWI was less than 1,220 mL/day, there was a significant negative connection between PWI and osteoporosis risk (OR = 0.79; 95% CI: 0.70-0.89; p < 0.001); nevertheless that association was not significant when PWI was greater than 1,220 mL/day (OR = 1.06; 95% CI: 0.95-1.17; p = 0.288).

Conclusion

The outcomes of our investigation indicated that among middle-aged and older US adults, a higher PWI was connected with a moderately reduced osteoporosis risk. Managing PWI might reduce the osteoporosis risk.

Trabecular bone score to assess bone microarchitecture in end-stage renal disease patients

RATIONALE

This study evaluates TBS for estimating bone microarchitecture in ESRD patients using HR-pQCT as the reference technique.

MAIN RESULTS

TBS correlates significantly with vBMD and bone microarchitecture, unlike aBMD.

SIGNIFICANCE

TBS may complement bone health assessment in ESRD patients by offering additional information alongside aBMD.

PURPOSE

Given the high fracture risk, non-invasive techniques for assessing bone fragility in chronic kidney disease (CKD) remain important. Trabecular bone score (TBS) may provide additional information that could help guide treatment and follow-up decisions. The aim of this study is to investigate whether TBS reflects bone microarchitecture in end-stage renal disease (ESRD) patients, using high-resolution peripheral quantitative computed tomography (HR-pQCT) as the reference technique. Additionally, we aim to identify parameters associated with a low TBS.

METHODS

Seventy-five ESRD patients were included at the time of kidney transplantation (KTx). Areal bone mineral density (aBMD) was analyzed using dual-energy X-ray absorptiometry (DXA). TBS was assessed from the L1-L4 area during DXA. Volumetric BMD (vBMD) and bone microarchitecture at tibia and radius sites were analyzed using HR-pQCT.

RESULTS

In ESRD patients, those with TBS < 1.370 were older and had a higher body mass index (BMI). In contrast to T-score-based classification (≤ -2.5 or > -2.5), low TBS was linked to significantly lower trabecular and cortical vBMD, reduced trabecular bone volume fraction (BV/TV) and trabecular number (Tb.N), and increased trabecular separation (Tb.Sp). In multivariate analysis, older age, higher BMI, and lower Tb.N remained independently associated with low TBS, while no HR-pQCT parameters were linked to low aBMD (T-score ≤ -2.5).

CONCLUSION

TBS correlates with both trabecular and cortical parameters measured by HR-pQCT, potentially offering a complementary perspective on bone microstructure compared to aBMD. At the time of KTx, a low TBS appears to better discriminate patients with significantly lower vBMD than aBMD alone.

Trends in disability (2001-2019), chronic medical conditions (1996-2020), and mortality (1995-2020) in Japanese older adults: analyses based on national datasets

BACKGROUND

The overall health status of older adults in Japan has reportedly improved. However, it is unclear whether such improvement has occurred in the baby boomer generation, the oldest of whom turned 65 in 2015. In addition, the health status of oldest-old adults (aged > 85 years) was not examined extensively in previous studies. This study aimed to characterize trends in disability and chronic medical conditions in adults aged 65-89 years which includes the baby boomer generation.

METHODS

From the Comprehensive Survey of Living Conditions (2001-2019), Patient Survey (1996-2020), and Vital Statistics (1995-2020), we documented disability rates, rates of treatment for nine chronic medical conditions (malignant neoplasms, diabetes mellitus, hypertension, ischemic heart disease, cerebrovascular diseases, pneumonia, fractures, osteoporosis, chronic kidney disease, and joint disorders), total mortality rates, and rates of mortality from specific causes (malignant neoplasms, heart diseases, cerebrovascular diseases, and pneumonia) in both sexes and in five age groups (65-69, 70-74, 75-79, 80-84, and 85-89 years).

RESULTS

Overall, rates of disability decreased significantly in both sexes. Both total mortality rates and rates of mortality from specific medical causes declined significantly. These trends were observed in the baby boomer generation. The rates of treatment for most medical conditions also significantly decreased. However, the treatment rates of diabetes mellitus, pneumonia, and fractures in adults aged 85-89 years remained high or did not decrease. In contrast, the treatment rates of chronic kidney disease steadily increased over time.

CONCLUSIONS

Overall health status continues to improve in older Japanese adults, including the baby boomer generation and the oldest-old cohort. However, for several diseases, no improvement was observed; thus, further public health interventions are necessary.

U-shaped association between TC/HDL-C ratio and osteoporosis risk in older adults

This study aimed to evaluate the association between the total cholesterol to high-density lipoprotein cholesterol (TC/HDL-C) ratio and the risk of osteoporosis in older adults. A cross-sectional analysis was conducted using data from 7,465 individuals aged 60 and above from the 2005-2020 National Health and Nutrition Examination Survey (NHANES). The TC/HDL-C ratio was calculated and divided into quartiles. Osteoporosis was defined by self-reported physician diagnosis or dual-energy x-ray absorptiometry (DXA) measurements. Multivariable logistic regression models assessed the association between the TC/HDL-C ratio and osteoporosis prevalence. Restricted cubic splines were used to explore non-linear associations and threshold effects. Among the participants, 1,608 had osteoporosis. A higher TC/HDL-C ratio was inversely associated with osteoporosis (OR: 0.92, 95% CI: 0.86-0.99, p = 0.02). The analysis revealed a U-shaped association (p for nonlinearity = 0.005) with a threshold at 4.66. Below this threshold, the TC/HDL-C ratio was negatively associated with osteoporosis (OR: 0.83, 95% CI: 0.72-0.94, p = 0.010), while no significant association was observed above the threshold. In sex-specific analyses, a U-shaped relationship was found in women, with a threshold at 4.35 (p for nonlinearity = 0.0016), but no significant association was found in men. The TC/HDL-C ratio demonstrates a U-shaped association with osteoporosis risk in older adults, particularly in women. Further longitudinal studies are required to validate these findings and determine optimal lipid management strategies for osteoporosis prevention.

Association Between Calcium Level, Bone Mineral Density, and Hip Fracture: Analysis Based on NHANES Data

Introduction: The relationships between calcium, bone mineral density, and hip fracture have been studied for a long time, but there are still different opinions on the matter. The aim of this study was to decipher the relationship between these factors from National Health and Nutrition Examination Survey (NHANES) data. Methods: After we performed data cleaning for the obtained NHANES data, we used multiple imputation to obtain the complete data and conducted an analysis for different variables. First, by using multivariate linear regression models, we confirmed the association between calcium and bone mineral density, and then we confirmed the association between bone mineral density and hip fracture by using multivariate logistic regression models. A mediation analysis of these variables was performed. Results: The analysis in this study included data on 18,003 participants from the NHANES, and we were able to find a strong association between calcium and bone mineral density (p < 0.001). The association between bone mineral density and hip fracture was also significant (p < 0.001). One augmented gram of daily calcium intake was associated with a 0.04 unit increase in BMD level, and a one unit increase in BMD level could downgrade the occurrence of hip fracture for 5.4 times. The mediation analysis showed that the femur BMD level and total BMD level have a mediating relationship with hip fracture, and no clear relationship among calcium, BMD, and hip fracture could be established. Conclusions: Although it is difficult to draw strict conclusions from the mediation analysis in this study, we can observe a clear association between calcium and BMD as well as an association between BMD and hip fracture.

The Diagnosis and Therapy of Osteoporosis in Gaucher Disease

Gaucher disease is a rare lysosomal storage disorder characterized by the accumulation of glucocerebroside lipids within multiple organs due to a deficiency of the lysosomal enzyme (acid β-glucosidase). It is an inherited autosomal recessive disease. The onset of symptoms can vary depending on disease type and severity, with milder forms presenting in adulthood. The main clinical manifestations include cytopenia, splenomegaly, hepatomegaly, and bone lesions. GD is characterized by several bone manifestations, such as osteopenia/osteoporosis, focal lytic or sclerotic lesions, osteonecrosis acute or chronic bone pain, Erlenmeyer flask deformity, and subchondral joint collapse with secondary degenerative arthritis. In 70-100% of patients affected by Gaucher disease type 1, clinical or radiographic evidence of bone disease occurs. Among bone complications, osteoporosis is very common, but its etiopathogenesis in GD is not completely clear. Results deriving from experimental studies support the hypothesis that there is an aberrant activity of both osteoclasts and osteoblasts due to several factors, resulting in impaired bone turnover. Bone complications represent the main cause of pain, disability, and reduced quality of life in these patients. Therefore, there is a need to enhance awareness among physicians on the skeletal manifestations throughout life of GD patients, in order to improve diagnosis and management of bone complications. In particular, this narrative review focuses on risk of bone fragility in GD, etiopathogenetic hypotheses, epidemiological data, diagnosis, monitoring, and treatment of osteoporosis in patients suffering from Gaucher disease, specifying the challenges not yet addressed.

Nrf2 Activation as a Therapeutic Target for Flavonoids in Aging-Related Osteoporosis

Biological aging is a substantial change that leads to different diseases, including osteoporosis (OP), a condition involved in loss of bone density, deterioration of bone structure, and increased fracture risk. In old people, there is a natural decline in bone mineral density (BMD), exacerbated by hormonal changes, particularly during menopause, and it continues in the early postmenopausal years. During this transition time, hormonal alterations are linked to elevated oxidative stress (OS) and decreased antioxidant defenses, leading to a significant increase in OP. Aging is significantly associated with an abnormal ratio of oxidant/antioxidant and modified nuclear factor erythroid-derived two related factor2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) pathway. OS adversely affects bone health by promoting osteoclastic (bone resorbing) activity and impairing osteoblastic (bone-forming cells). Nrf2 is critical in controlling OS and various cellular processes. The expression of Nrf2 is linked to multiple age-related diseases, including OP, and Nrf2 deficiency leads to unbalanced bone formation/resorption and a consequent decline in bone mass. Various drugs are available for treating OP; however, long-term uses of these medicines are implicated in diverse illnesses such as cancer, cardiovascular, and stroke. At the same time, multiple categories of natural products, in particular flavonoids, were proposed as safe alternatives with antioxidant activity and substantial anti-osteoporotic effects.

Studies on the Role of MAP4K2, SPI1, and CTSD in Osteoporosis

Osteoporosis (OP) is a prevalent skeletal disorder characterized by an imbalance between bone resorption and bone formation, resulting in a significant global burden. Previous research utilizing bioinformatics analysis has identified MAP4K2, SPI1, and CTSD as hub genes associated with OP. In this current investigation, we have successfully established a differential expression system of MAP4K2, SPI1, and CTSD in rat bone marrow mesenchymal stem cells (BMSCs) through transfection techniques. Additionally, the CCK-8 assay was employed to assess cell proliferation, while the alkaline phosphatase (ALP) activity assay and ALP staining assay were utilized to evaluate osteogenic differentiation. Alizarin red staining was employed to detect mineralization of BMSCs. Furthermore, the expression of relevant genes and molecules associated with the MAPK signaling pathway, autophagy, and apoptosis in the sera of rat BMSCs were examined using quantitative real-time polymerase chain reaction (qRT-PCR). The purpose of this study was to preliminarily investigate whether MAP4K2, SPI1, and CTSD have an effect on the osteogenic capacity of rat BMSCs and whether these genes, when differentially expressed, affect the expression of related genes in the MAPK, autophagy, and apoptosis signaling pathways and thus the osteogenic function of BMSCs. In summary, the findings of this study indicate that MAP4K2 and CTSD exert significant influence on the proliferation, osteogenic differentiation, and mineralization processes of rat BMSCs cells. Furthermore, these proteins may contribute to the development of OP through their involvement in the regulation of autophagy and apoptosis. Conversely, our investigation did not reveal any discernible impact of SPI1 on OP-related phenotypes. Consequently, this research serves as a fundamental basis for further exploration of potential therapeutic targets for the treatment of OP.

Correlation of thyroid function and sensitivity to thyroid hormone with spinal bone mineral content, bone mineral density, and osteoporotic vertebral fracture: A cross-sectional study based on NHANES

Previous studies have demonstrated that thyroid hormone plays an important role in normal bone development, bone metabolism, and establishment of peak bone mass. However, the correlation of thyroid status with bone mineral content (BMC), bone mineral density (BMD), and osteoporotic vertebral fracture (OVF) is rarely discussed. The current study probes into the potential association between thyroid status and spinal BMC, BMD, and OVF from a novel perspective of thyroid function (TF) and sensitivity to thyroid hormone based on the National Health and Nutrition Examination Survey database. A total of 1844 participants were included in this study. The association of thyroid status with outcome variables, like spinal BMC, BMD, and OVF, was analyzed using thyroid function indices and sensitivity to thyroid hormone indices as influence factors. The correlation of them were assessed using univariate and multivariable weighted linear regression, weighted logistic regression models, restricted cubic spline model, and subgroup analyses. The results of this study showed that the association of free triiodothyronine (FT3)/free thyroxine (FT4) with BMC remained negatively associated after adjustment for all covariates. Higher thyroid peroxidase antibody (TPOAb) was significantly associated with an increased risk of developing OVF in both unadjusted and adjusted models. In addition, the results of the restricted cubic spline model were consistent with the weighted multivariate regression analysis after adjustment. The results of this cross-sectional study showed that higher FT3/FT4 and TPOAb were associated with decreased spinal BMC and the increased risk of OVF, indicating a complex link between thyroid status and bone health. Therefore, patients with hyperthyroidism, hypothyroidism, autoimmune thyroid disease, or abnormal peripheral thyroid sensitivity, especially who with elevated TPOAb or FT3/FT4, should focus on the prevention of vertebral osteopenia, osteoporosis, and OVF.

Ultra-low dose hip CT-based automated measurement of volumetric bone mineral density at proximal femoral subregions

BACKGROUND

Forty to fifty percent of women and 13%-22% of men experience an osteoporosis-related fragility fracture in their lifetimes. After the age of 50 years, the risk of hip fracture doubles in every 10 years. x-Ray based DXA is currently clinically used to diagnose osteoporosis and predict fracture risk. However, it provides only 2-D representation of bone and is associated with other technical limitations. Thus, alternative methods are needed.

PURPOSE

To develop and evaluate an ultra-low dose (ULD) hip CT-based automated method for assessment of volumetric bone mineral density (vBMD) at proximal femoral subregions.

METHODS

An automated method was developed to segment the proximal femur in ULD hip CT images and delineate femoral subregions. The computational pipeline consists of deep learning (DL)-based computation of femur likelihood map followed by shape model-based femur segmentation and finite element analysis-based warping of a reference subregion labeling onto individual femur shapes. Finally, vBMD is computed over each subregion in the target image using a calibration phantom scan. A total of 100 participants (50 females) were recruited from the Genetic Epidemiology of COPD (COPDGene) study, and ULD hip CT imaging, equivalent to 18 days of background radiation received by U.S. residents, was performed on each participant. Additional hip CT imaging using a clinical protocol was performed on 12 participants and repeat ULD hip CT was acquired on another five participants. ULD CT images from 80 participants were used to train the DL network; ULD CT images of the remaining 20 participants as well as clinical and repeat ULD CT images were used to evaluate the accuracy, generalizability, and reproducibility of segmentation of femoral subregions. Finally, clinical CT and repeat ULD CT images were used to evaluate accuracy and reproducibility of ULD CT-based automated measurements of femoral vBMD.

RESULTS

Dice scores of accuracy (n = 20), reproducibility (n = 5), and generalizability (n = 12) of ULD CT-based automated subregion segmentation were 0.990, 0.982, and 0.977, respectively, for the femoral head and 0.941, 0.970, and 0.960, respectively, for the femoral neck. ULD CT-based regional vBMD showed Pearson and concordance correlation coefficients of 0.994 and 0.977, respectively, and a root-mean-square coefficient of variation (RMSCV) (%) of 1.39% with the clinical CT-derived reference measure. After 3-digit approximation, each of Pearson and concordance correlation coefficients as well as intraclass correlation coefficient (ICC) between baseline and repeat scans were 0.996 with RMSCV of 0.72%. Results of ULD CT-based bone analysis on 100 participants (age (mean ± SD) 73.6 ± 6.6 years) show that males have significantly greater (p < 0.01) vBMD at the femoral head and trochanteric regions than females, while females have moderately greater vBMD (p = 0.05) at the medial half of the femoral neck than males.

CONCLUSION

Deep learning, combined with shape model and finite element analysis, offers an accurate, reproducible, and generalizable algorithm for automated segmentation of the proximal femur and anatomic femoral subregions using ULD hip CT images. ULD CT-based regional measures of femoral vBMD are accurate and reproducible and demonstrate regional differences between males and females.

Segmentation methods for quantifying X-ray Computed Tomography based biomarkers to assess hip fracture risk: a systematic literature review

Background

The success of using bone mineral density and/or FRAX to predict femoral osteoporotic fracture risk is modest since they do not account for mechanical determinants that affect bone fracture risk. Computed Tomography (CT)-based geometric, densitometric, and finite element-derived biomarkers have been developed and used as parameters for assessing fracture risk. However, to quantify these biomarkers, segmentation of CT data is needed. Doing this manually or semi-automatically is labor-intensive, preventing the adoption of these biomarkers into clinical practice. In recent years, fully automated methods for segmenting CT data have started to emerge. Quantifying the accuracy, robustness, reproducibility, and repeatability of these segmentation tools is of major importance for research and the potential translation of CT-based biomarkers into clinical practice.

Methods

A comprehensive literature search was performed in PubMed up to the end of July 2024. Only segmentation methods that were quantitatively validated on human femurs and/or pelvises and on both clinical and non-clinical CT were included. The accuracy, robustness, reproducibility, and repeatability of these segmentation methods were investigated, reporting quantitatively the metrics used to evaluate these aspects of segmentation. The studies included were evaluated for the risk of, and sources of bias, that may affect the results reported.

Findings

A total of 54 studies fulfilled the inclusion criteria. The analysis of the included papers showed that automatic segmentation methods led to accurate results, however, there may exist a need to standardize reporting of accuracy across studies. Few works investigated robustness to allow for detailed conclusions on this aspect. Finally, it seems that the bone segmentation field has only addressed the concept of reproducibility and repeatability to a very limited extent, which entails that most of the studies are at high risk of bias.

Interpretation

Based on the studies analyzed, some recommendations for future studies are made for advancing the development of a standardized segmentation protocol. Moreover, standardized metrics are proposed to evaluate accuracy, robustness, reproducibility, and repeatability of segmentation methods, to ease comparison between different approaches.

Calcium-based phosphate binders and bone mineral density in patients undergoing hemodialysis: a retrospective cohort study

BACKGROUND

Calcium supplements are commonly prescribed to prevent fractures in patients with osteoporosis. Nonetheless, they are generally eschewed in hemodialysis patients because they increase vascular calcification and induce cardiovascular disease. This retrospective cohort study aimed to investigate the effect of calcium-based phosphate binders (CBPB) on bone mineral density (BMD) in hemodialysis patients.

METHODS

Outpatients on dialysis who underwent BMD measurement from January to December 2017, whose data on BMD trends and CBPB administration were recorded over the next 4 years, were enrolled. Patients receiving anti-osteoporotic medications were excluded. The association between the presence and duration of CBPB administration and changes in BMD was evaluated.

RESULTS

The femoral neck's BMD decreased from 0.836 g/cm2 (0.702-0.952) to 0.764 g/cm2 (0.636-0.896) (P < 0.001) in the non-CBPB group (patients who never received CBPB over 4 years, n = 32). The CBPB group (n = 56) exhibited only a minute decrease from 0.833 g/cm2 (0.736-0.965) to 0.824 g/cm2 (0.706-0.939) (P = 0.004). Multivariate linear regression analysis revealed better BMD maintenance in the CBPB group [β-coefficient (95% CI): 0.033 (0.001-0.065); P = 0.046] than in the non-CBPB group. Additionally, the prolonged-CBPB administration group showed superior BMD preservation [β-coefficient (95% CI): 0.038 (0.001-0.076); P = 0.042].

CONCLUSION

CBPB administration may be associated with BMD maintenance.

Characterization of gut microbiota in the Uyghur osteopenia population

The objectives of this study were to investigate the composition of gut microbiota and its relationship with bone loss in the Uyghur osteopenia population, identify potential disease-related taxa and collect information for the prevention and treatment of osteopenia in different people by regulating gut microbiota. We selected Uyghur residents, measured their heel BMD, collected faeces and general information, grouped them by BMD level, obtained faecal 16S rRNA sequences, and compared and analysed the differences between the groups. This study showed that the numbers of OTUs and species in the gut microbiota in the osteopenia group were higher than those in the control. At the phylum level, Erysipelotrichia was more abundant in the osteopenia group. At the genus level, Phascolarctobacterium was less abundant, and Ruminiclostridium_5 was more abundant in the osteopenia group compared to the control. Phascolarctobacterium and Z-score were positively correlated, and Ruminiclostridium_5 was negatively correlated with T and Z score. The different composition of the gut microbiota in Uyghur osteopenia patients and controls found in this study fills a knowledge gap in this ethnic group. The relationship between Uyghur osteopenia and BMD-associated bacterial genera deserves further exploration.

A Computed Tomography-Based Fracture Prediction Model With Images of Vertebral Bones and Muscles by Employing Deep Learning: Development and Validation Study

BACKGROUND

With the progressive increase in aging populations, the use of opportunistic computed tomography (CT) scanning is increasing, which could be a valuable method for acquiring information on both muscles and bones of aging populations.

OBJECTIVE

The aim of this study was to develop and externally validate opportunistic CT-based fracture prediction models by using images of vertebral bones and paravertebral muscles.

METHODS

The models were developed based on a retrospective longitudinal cohort study of 1214 patients with abdominal CT images between 2010 and 2019. The models were externally validated in 495 patients. The primary outcome of this study was defined as the predictive accuracy for identifying vertebral fracture events within a 5-year follow-up. The image models were developed using an attention convolutional neural network-recurrent neural network model from images of the vertebral bone and paravertebral muscles.

RESULTS

The mean ages of the patients in the development and validation sets were 73 years and 68 years, and 69.1% (839/1214) and 78.8% (390/495) of them were females, respectively. The areas under the receiver operator curve (AUROCs) for predicting vertebral fractures were superior in images of the vertebral bone and paravertebral muscles than those in the bone-only images in the external validation cohort (0.827, 95% CI 0.821-0.833 vs 0.815, 95% CI 0.806-0.824, respectively; P<.001). The AUROCs of these image models were higher than those of the fracture risk assessment models (0.810 for major osteoporotic risk, 0.780 for hip fracture risk). For the clinical model using age, sex, BMI, use of steroids, smoking, possible secondary osteoporosis, type 2 diabetes mellitus, HIV, hepatitis C, and renal failure, the AUROC value in the external validation cohort was 0.749 (95% CI 0.736-0.762), which was lower than that of the image model using vertebral bones and muscles (P<.001).

CONCLUSIONS

The model using the images of the vertebral bone and paravertebral muscle showed better performance than that using the images of the bone-only or clinical variables. Opportunistic CT screening may contribute to identifying patients with a high fracture risk in the future.

Fracture Risk Associated with Different Numbers and Combinations of Lumbar Vertebrae: The Manitoba BMD Registry

Bone mineral density (BMD) is widely used for assessment of fracture risk. For the lumbar spine, BMD is typically measured from L1-L4 as it provides the largest area for assessment with the best measurement precision. Structural artifact often confounds spine BMD in clinical practice, and the International Society for Clinical Densitometry (ISCD) recommends removing vertebrae with artifact when reporting spine BMD. In its most recent position statements, the ISCD recommended against the use of a single vertebra when reporting spine BMD but stated that further studies should be done. The current analysis was performed to compare the performance of BMD from different numbers and combination of vertebral levels on fracture prediction in a large clinical registry of DXA tests for the Province of Manitoba, Canada. The study population comprised 39,727 individuals aged 40 years and older (mean age 62.7 years, 91.0 % female) with baseline DXA after excluding those with evidence of structural artifact. Mean follow-up for ascertaining fracture outcomes was 8.7 years. Area under the curve (AUC) for incident fracture risk stratification was statistically significant regardless of the BMD measurement site or fracture outcome. AUC differences with the various numbers and combinations of vertebral levels including a single vertebral body were small (less than or equal to 0.01). More substantial AUC differences were seen for femoral neck and total hip BMD versus L1-L4 BMD, approaching 0.1 for hip fracture stratification. In summary, we found that using combinations of fewer than 4 vertebrae including individual lumbar vertebrae predicted incident fractures. Importantly, differences between these different combinations were small when compared with L1-L4. Spine BMD was a better predictor of incident spine fracture compared to the hip, whereas the hip was better for hip fracture and overall fracture prediction.

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women

BACKGROUND

Although it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear.

METHODS

A total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck.

RESULTS

Compared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased.

CONCLUSION

These results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

Weight-adjusted waist index is a potential early predictor of degraded bone microarchitecture: A cross-sectional study of the national health and nutrition examination survey 2007-2008

PURPOSE

This study aimed to investigate the association between weight-adjusted waist index (WWI) and trabecular bone score (TBS) and to assess the ability of WWI to identify individuals with degraded bone microarchitecture (DBMA).

METHODS

This cross-sectional study included participants aged 20 and older from the National Health and Nutrition Examination Survey. Furthermore, WWI was calculated by waist circumference and body weight. In addition, linear regression models were employed to investigate the association between WWI and TBS, while logistic regression models were employed to determine the association between WWI and the risk of DBMA. Finally, the performance of WWI in identifying individuals with DBMA was using the receiver operating characteristic (ROC) curves with area under the ROC curve.

RESULTS

A total of 4,179 participants with a mean age of 49.90 years were included in the final analysis. WWI was negatively associated with TBS and positively associated with an increased risk of DBMA. Furthermore, the associations between WWI and TBS, as well as DBMA risk, were stable regardless of stratification by age, sex, race, or body mass index (BMI). Moreover, WWI achieved good performances in identifying individuals with DBMA or low TBS. In addition, the combination of WWI and BMI showed better performances in identifying individuals with DBMA or low TBS than WWI or BMI alone.

CONCLUSION

WWI established a negative association with TBS and a positive association with the risk of DBMA. Clinicians should be alert to the potential risk of DBMA among individuals with high WWI. Moreover, WWI, alone or in combination with BMI, has the potential to serve as an early screening strategy in identifying individuals with DBMA.

DXA-based statistical models of shape and intensity outperform aBMD hip fracture prediction: A retrospective study

Areal bone mineral density (aBMD) currently represents the clinical gold standard for hip fracture risk assessment. Nevertheless, it is characterised by a limited prediction accuracy, as about half of the people experiencing a fracture are not classified as at being at risk by aBMD. In the context of a progressively ageing population, the identification of accurate predictive tools would be pivotal to implement preventive actions. In this study, DXA-based statistical models of the proximal femur shape, intensity (i.e., density) and their combination were developed and employed to predict hip fracture on a retrospective cohort of post-menopausal women. Proximal femur shape and pixel-by-pixel aBMD values were extracted from DXA images and partial least square (PLS) algorithm adopted to extract corresponding modes and components. Subsequently, logistic regression models were built employing the first three shape, intensity and shape-intensity PLS components, and their ability to predict hip fracture tested according to a 10-fold cross-validation procedure. The area under the ROC curves (AUC) for the shape, intensity, and shape-intensity-based predictive models were 0.59 (95%CI 0.47-0.69), 0.80 (95%CI 0.70-0.90) and 0.83 (95%CI 0.73-0.90), with the first being significantly lower than the latter two. aBMD yielded an AUC of 0.72 (95%CI 0.59-0.82), found to be significantly lower than the shape-intensity-based predictive model. In conclusion, a methodology to assess hip fracture risk uniquely based on the clinically available imaging technique, DXA, is proposed. Our study results show that hip fracture risk prediction could be enhanced by taking advantage of the full set of information DXA contains.

Links among Obesity, Type 2 Diabetes Mellitus, and Osteoporosis: Bone as a Target

Obesity, type 2 diabetes mellitus (T2DM) and osteoporosis are serious diseases with an ever-increasing incidence that quite often coexist, especially in the elderly. Individuals with obesity and T2DM have impaired bone quality and an elevated risk of fragility fractures, despite higher and/or unchanged bone mineral density (BMD). The effect of obesity on fracture risk is site-specific, with reduced risk for several fractures (e.g., hip, pelvis, and wrist) and increased risk for others (e.g., humerus, ankle, upper leg, elbow, vertebrae, and rib). Patients with T2DM have a greater risk of hip, upper leg, foot, humerus, and total fractures. A chronic pro-inflammatory state, increased risk of falls, secondary complications, and pharmacotherapy can contribute to the pathophysiology of aforementioned fractures. Bisphosphonates and denosumab significantly reduced the risk of vertebral fractures in patients with both obesity and T2DM. Teriparatide significantly lowered non-vertebral fracture risk in T2DM subjects. It is important to recognize elevated fracture risk and osteoporosis in obese and T2DM patients, as they are currently considered low risk and tend to be underdiagnosed and undertreated. The implementation of better diagnostic tools, including trabecular bone score, lumbar spine BMD/body mass index (BMI) ratio, and microRNAs to predict bone fragility, could improve fracture prevention in this patient group.

A Mendelian randomization study on the association of bone mineral density with periodontitis

OBJECTIVE

Observational studies indicated that individuals with osteoporosis could be at an increased risk of periodontitis. This study aimed to investigate whether there is a causal association of bone mineral density (BMD) with periodontitis using Mendelian randomization (MR).

MATERIALS AND METHODS

Summary statistics were sourced from genome-wide association study on BMD measured at different skeletal sites, including estimated heel BMD (eBMD, N = 426,824), forearm BMD (FA-BMD, N = 8143), femoral neck BMD (FN-BMD, N = 32,735), and lumbar spine BMD (LS-BMD, N = 28,498). Genetic variants of periodontitis (N = 45,563) and loose teeth (N = 461,031) were used as outcome surrogates. Inverse variance weighted meta-analysis (IVW) was adopted as main analyses. Other sensitivity MR approaches were used to boost power and account for pleiotropy.

RESULTS

IVW results suggested no evidence for a causal association of any phenotypes of BMD with periodontitis (eBMD, odds ratio [OR] = 0.984, 95% confidence interval [CI] = 0.885-1.083; FA-BMD, OR = 1.028, 95%CI = 0.864-1.193; FN-BMD, OR = 1.033, 95%CI = 0.896-1.169; LS-BMD, OR = 0.991, 95%CI =0.878-1.103; all P > 0.65). Such null associations were consistent through other sensitivity MR approaches. Similarly, no significant causal effects of BMD on loose teeth were found.

CONCLUSIONS

Within the limitation of the study, our MR estimates suggested that a decreased BMD is unlikely to substantially increase the risk of periodontitis.

Association between lumbar muscle size and bone mineral density in nonfractured postmenopausal women with and without osteoporosis

OBJECTIVE

Estrogen deficiency in postmenopausal women is associated with bone loss and a decline in muscle mass. However, the associations between lumbar muscle size and bone mineral density (BMD) in postmenopausal women with and without osteoporosis remain unclear. The aim of this study was to investigate the associations between lumbar muscle size and BMD in nonfractured postmenopausal women with osteoporosis and those with osteopenia.

METHODS

A total of 89 postmenopausal women with osteopenia (n = 53) and osteoporosis (n = 36) were retrospectively enrolled in this study from 2014 to 2022. All participants underwent lumbar magnetic resonance imaging and dual-energy absorptiometry within a month. The lean lumbar muscle sizes at different lumbar levels were quantitatively evaluated on axial T1-weighted images. The associations between lumbar muscle size and BMD were analyzed using Pearson's correlation analysis.

RESULTS

The osteoporosis group had significantly smaller lean psoas muscle sizes than the osteopenia group. Based on the correlation analysis, the erector spinae and multifidus muscle sizes were significantly associated with lumbar and femoral neck BMDs in the osteoporosis group. However, no significant association was found between lean psoas muscle size and BMDs in the osteopenia group. Thus, the associations between lumbar muscle decline and bone loss differed between postmenopausal women with osteoporosis and those with osteopenia.

CONCLUSIONS

The study findings suggest differences in the associations between BMD and lumbar muscle size between postmenopausal women with osteoporosis and those with osteopenia.

Significance of non-motor symptoms and development of a screening tool for osteoporosis in Parkinson's disease

BACKGROUND AND PURPOSE

Parkinson's disease (PD) patients have a higher likelihood of having osteoporosis compared to controls, therefore deserving special attention. This study was to 1) investigate the association of non-motor symptoms with osteoporosis amongst PD patients, and 2) develop screening tools for osteoporosis.

MATERIALS AND METHODS

PD Patients were included (n = 109). The factors/variables were obtained from clinical records due to the retrospective nature of this study. The bone mineral density (BMD) of the lumbar spine and femoral neck was examined using a dual-energy X-ray absorptiometry machine, according to which they were categorized as either having (T-score ≤ -2.5) or not having osteoporosis (T-score>-2.5) at the two sites. The non-motor symptoms were assessed using clinical scales, including non-motor experiences of daily living, depression, anxiety, cognitive function, and autonomic function. The potential covariates included demographic and clinical factors/variables, such as age and sex. Logistic regression was used to investigate the associations and establish the screening tools.

RESULTS

Patients with autonomic dysfunction had significantly (p = 0.011) higher odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction after adjusting for sex, disease duration, and body mass index, demonstrating a strong association (odds ratio=12.81). Based on the four factors/variables, a screening tool with a good accuracy was established (C-statistic = 0.85).

CONCLUSION

PD patients with autonomic dysfunction had greater odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction. The screening tool may lay a foundation for developing screening models with higher accuracy to identify which PD patients may require a BMD test.

A systematic analysis on global epidemiology and burden of foot fracture over three decades

PURPOSE

To comprehensively analyze the geographic and temporal trends of foot fracture, understand its health burden by age, sex, and sociodemographic index (SDI), and explore its leading causes from 1990 to 2019.

METHODS

The datasets in the present study were generated from the Global Burden of Diseases Study 2019, which included foot fracture data from 1990 to 2019. We extracted estimates along with the 95% uncertainty interval (UI) for the incidence and years lived with disability (YLDs) of foot fracture by location, age, gender, and cause. The epidemiology and burden of foot fracture at the global, regional, and national level was exhibited. Next, we presented the age and sex patterns of foot fracture. The leading cause of foot fracture was another focus of this study from the viewpoint of age, sex, and location. Then, Pearson's correlations between age-standardized rate (ASR), SDI, and estimated annual percentage change were calculated.

RESULTS

The age-standardized incidence rate was 138.68 (95% UI: 104.88 - 182.53) per 100,000 persons for both sexes, 174.24 (95% UI: 134.35 - 222.49) per 100,000 persons for males, and 102.19 (95% UI: 73.28 - 138.00) per 100,000 persons for females in 2019. The age-standardized YLDs rate was 5.91 (95% UI: 3.58 - 9.25) per 100,000 persons for both genders, 7.35 (95% UI: 4.45 - 11.50) per 100,000 persons for males, and 4.51 (95% UI: 2.75 - 7.03) per 100,000 persons for females in 2019. The global incidence and YLDs of foot fracture increased in number and decreased in ASR from 1990 to 2019. The global geographical distribution of foot fracture is uneven. The incidence rate for males peaked at the age group of 20 - 24 years, while that for females increased with advancing age. The incidence rate of older people was rising, as younger age incidence rate declined from 1990 to 2019. Falls, exposure to mechanical forces, and road traffic injuries were the 3 leading causes of foot fracture. Correlations were observed between ASR, estimated annual percentage change, and SDI.

CONCLUSIONS

The burden of foot fracture remains high globally, and it poses an enormous public health challenge, with population ageing. It is necessary to allocate more resources to the high-risk populations. Targeted realistic intervention policies and strategies are warranted.

The practicality of using bone impact microindentation in a population-based study of women: A Geelong-Osteoporosis Study

Impact microindentation (IMI) is a minimally invasive technique that allows the assessment of bone material strength index (BMSi) in vivo, by measuring the depth of a micron-sized, spherical tip into cortical bone that is then indexed to the depth of the tip into a reference material. In this study, we aimed to assess the practicality of its application in 99 women aged 42-84 yr from the Geelong Osteoporosis Study. Impact microindentation was performed in the mid-shaft of the right tibia using the OsteoProbe. Immediately following measurement, each participant was requested to rate on a Visual Analogue Scale [0-10] the level of discomfort anticipated and experienced, any initial reluctance towards the measurement and whether they were willing to repeat the measurement. Of 99 potential participants who attended this assessment phase, 55 underwent IMI measurement. Reasons for non-measurement in 44 women were existing skin conditions (n = 8, 18.2 %) and excessive soft tissue around mid-tibial region (n = 32, 72.2 %). An additional four (9.1 %) participants did not provide any reasons for declining. For 55 participants who had underwent IMI, the expectation for pain when briefed about the procedure was low (2.28 ± 2.39), as was pain experienced during the measurement (0.72 ± 1.58). Participants were not reluctant to undergo the measurement (0.83 ± 1.67), and all indicated a willingness to repeat the measurement. Results of this study showed that the IMI technique is well tolerated and accepted by women participating in the Geelong Osteoporosis Study, suggesting that the technique shows promise in a research or clinical setting.

Pre-operative bone quality deficits and risk of complications following spine fusion surgery among postmenopausal women

Poor bone quality is a risk factor for complications after spinal fusion surgery. This study investigated pre-operative bone quality in postmenopausal women undergoing spine fusion and found that those with small bones, thinner cortices and surgeries involving more vertebral levels were at highest risk for complications.

PURPOSE

Spinal fusion is one of the most common surgeries performed worldwide. While skeletal complications are common, underlying skeletal deficits are often missed by pre-operative DXA due to artifact from spinal pathology. This prospective cohort study investigated pre-operative bone quality using high resolution peripheral CT (HRpQCT) and its relation to post-operative outcomes in postmenopausal women, a population that may be at particular risk for skeletal complications. We hypothesized that women with low volumetric BMD (vBMD) and abnormal microarchitecture would have higher rates of post-operative complications.

METHODS

Pre-operative imaging included areal BMD (aBMD) by DXA, cortical and trabecular vBMD and microarchitecture of the radius and tibia by high resolution peripheral CT. Intra-operative bone quality was subjectively graded based on resistance to pedicle screw insertion. Post-operative complications were assessed by radiographs and CTs.

RESULTS

Among 50 women enrolled (age 65 years), mean spine aBMD was normal and 35% had osteoporosis by DXA at any site. Low aBMD and vBMD were associated with "poor" subjective intra-operative quality. Skeletal complications occurred in 46% over a median follow-up of 15 months. In Cox proportional models, complications were associated with greater number of surgical levels (HR 1.19 95% CI 1.06-1.34), smaller tibia total area (HR 1.67 95% CI1.16-2.44) and lower tibial cortical thickness (HR 1.35 95% CI 1.05-1.75; model p < 0.01).

CONCLUSION

Women with smaller bones, thinner cortices and procedures involving a greater number of vertebrae were at highest risk for post-operative complications, providing insights into surgical and skeletal risk factors for complications in this population.

A convolutional neural network-based method for the generation of super-resolution 3D models from clinical CT images

BACKGROUND AND OBJECTIVE

The accurate evaluation of bone mechanical properties is essential for predicting fracture risk based on clinical computed tomography (CT) images. However, blurring and noise in clinical CT images can compromise the accuracy of these predictions, leading to incorrect diagnoses. Although previous studies have explored enhancing trabecular bone CT images to super-resolution (SR), none of these studies have examined the possibility of using clinical CT images from different instruments, typically of lower resolution, as a basis for analysis. Additionally, previous studies rely on 2D SR images, which may not be sufficient for accurate mechanical property evaluation, due to the complex nature of the 3D trabecular bone structures. The objective of this study was to address these limitations.

METHODS

A workflow was developed that utilizes convolutional neural networks to generate SR 3D models across different clinical CT instruments. The morphological and finite-element-derived mechanical properties of these SR models were compared with ground truth models obtained from micro-CT scans.

RESULTS

A significant improvement in analysis accuracy was demonstrated, where the new SR models increased the accuracy by up to 700 % compared with the low-resolution data, i.e. clinical CT images. Additionally, we found that the mixture of different CT image datasets may improve the SR model performance.

CONCLUSIONS

SR images, generated by convolutional neural networks, outperformed clinical CT images in the determination of morphological and mechanical properties. The developed workflow could be implemented for fracture risk prediction, potentially leading to improved diagnoses and subsequent clinical decision making.

Changes in Blood Pressure is Associated with Bone Loss in US Adults: A Cross-Sectional Study from NHANES 2005-2018

Hypertension and osteoporosis are common geriatric diseases, sharing similar risk factors. This study aims to investigate this association and explore relatively mixed variables. Our study included 12,787 eligible participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Included participants had valid data on hypertension and osteoporosis, without tumors, liver diseases, gout or thyroid diseases. We explored the association between hypertension and osteoporosis by logistic regression and examined blood pressure and BMD/BMC by linear and non-linear regression. Moreover, we used machine learning models to predict the importance of various factors in the occurrence of osteoporosis and evaluated causality by mendelian randomization. Our study found that osteoporosis is significantly associated with hypertension [OR 2.072 (95% CI 2.067-2.077), p < 0.001]. After adjusting for co-variances, the association remained significant [OR 1.223 (95% CI 1.220-1.227), p < 0.001]. Our study showed that osteoporosis is positively associated with hypertension in the US population. A variety of factors influence this relationship. Specific regulatory mechanisms and confounding factors need to be further investigated.

Rapid decline of kidney function increases fracture risk in the general population: Insights from TLGS

BACKGROUND

Although the association between Chronic Kidney Disease (CKD) and all-cause fractures was addressed in previous studies, the association between estimated glomerular filtration rate (eGFR) decline and fractures was poorly addressed. For the first time we examined the association between rapid kidney function decline (RKFD) and fracture incidence among Iranian general population.

METHODS

In a Tehranian community-based cohort, RKFD was defined as a 30 % decline in eGFR over 2-3 years. Cox proportional hazards models, adjusted for age, sex, current eGFR, diabetes mellitus, hypertension, dyslipidemia, current smoking, obesity status, waist circumference, prevalent cardiovascular diseases, aspirin, steroid use, education level, and marital status, were used to examine the association of RKFD with different fracture outcomes.

RESULTS

Among 5305 (3031 women) individuals aged ≥30 years, during the median follow-up of 9.62 years, 226 fracture events were observed. The multivariable hazard ratio of RKFD for any-fracture events, lower-extremity, and major osteoporotic fractures were 2.18 (95 % CI, 1.24-3.85), 2.32 (1.15-4.71), and 2.91 (1.29-6.58), respectively. These associations remained significant after accounting for the competing risk of death. The impact of RKFD on the development of incident all-cause fractures was not modified by gender [men: 2.64 (1.11-6.25) vs. women: 2.11 (1.00-4.47)] and according to current CKD status [without CKD: 2.34 (1.00-5.52) vs. with CKD: 2.59 (1.04-6.44)] (all P for interaction >0.5).

CONCLUSIONS

RKFD can increase the incidence of fractures among general population, the issue that was equally important among non-CKD individuals, emphasizing the need for early identification and management in those with rapidly declining eGFR.

Multidimensional characteristics of musculoskeletal pain and risk of hip fractures among elderly adults: the first longitudinal evidence from CHARLS

BACKGROUND

Hip fractures are a major public health concern among middle-aged and older adults. It is important to understand the associated risk factors to inform health policies and develop better prevention strategies. Musculoskeletal pain is a possible implicating factor, being associated with physical inactivity and risk of falls. However, the association between musculoskeletal pain and hip fractures has not been clearly investigated.

METHODS

A nationally representative sample of the Chinese population was obtained from the China Health and Retirement Longitudinal Study (CHARLS). The study collected patient information on their demographic characteristics, socioeconomic status, other health-related behavior, and history of musculoskeletal pain and hip fractures. Univariate and multivariate analyses were conducted to investigate the factors influencing the risk of hip fracture, including factors related to the individual and to musculoskeletal pain. P for trend test was performed to assess the trend of each continuous variable. The robustness and bias were assessed using the bootstrap method. Restricted cubic spline regression was utilized to identify linear or non-linear relationships.

RESULTS

Among the 18,813 respondents, a total of 215 individuals reported that they have experienced a hip fracture. An increased risk of hip fracture was associated with the presence of waist pain and leg pain (P < 0.05), as well as with an increased number of musculoskeletal pain sites (P < 0.05). For individuals aged 65 and above, a significant association was found between age and the risk of hip fracture (P < 0.05). Furthermore, respondents with lower education level had a higher risk of hip fracture compared to those with higher education levels (P < 0.05).

CONCLUSION

In the Chinese population, the risk of hip fracture was found to be associated with both the location and extent of musculoskeletal pain, as well as with other factors such as age and demographic characteristics. The findings of this study may be useful for informing policy development and treatment strategies, and provide evidence for comparison with data from other demographic populations.

Dehydrocostus lactone (DHC) promotes osteoblastic differentiation and mineralization through p38/RUNX-2 signaling

Dysregulation of osteoblastic differentiation is an important risk factor of osteoporosis, the therapy of which is challenging. Dehydrocostus lactone (DHC), a sesquiterpene isolated from medicinal plants, has displayed anti-inflammatory and antitumor properties. In this study, we investigated the effects of DHC on osteoblastic differentiation and mineralization of MC3T3-E1 cells. Interestingly, we found that DHC increased the expression of marker genes of osteoblastic differentiation, such as alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Additionally, DHC increased the expressions of collagen type I alpha 1 (Col1a1) and collagen type I alpha 2 (Col1a2). We also demonstrate that DHC increased ALP activity. Importantly, the Alizarin Red S staining assay revealed that DHC enhanced osteoblastic differentiation of MC3T3-E1 cells. Mechanistically, it is shown that DHC increased the expression of Runx-2, a central regulator of osteoblastic differentiation. Treatment with DHC also increased the levels of phosphorylated p38, and its blockage using its specific inhibitor SB203580 abolished the effects of DHC on runt-related transcription factor 2 (Runx-2) expression and osteoblastic differentiation, suggesting the involvement of p38. Based on these findings, we concluded that DHC might possess a capacity for the treatment of osteoporosis by promoting osteoblastic differentiation.

Follow-up Bone Mineral Density Testing: 2023 Official Positions of the International Society for Clinical Densitometry

Dual-energy X-ray absorptiometry (DXA) is the gold standard method for measuring bone mineral density (BMD) which is most strongly associated with fracture risk. BMD is therefore the basis for the World Health Organization's densitometric definition of osteoporosis. The International Society for Clinical Densitometry (ISCD) promotes best densitometry practices and its official positions reflect critical review of current evidence by domain experts. This document reports new official positions regarding follow-up DXA examinations based on a systematic review of literature published through December 2022. Adoption of official positions requires consensus agreement from an expert panel following a modified RAND protocol. Unless explicitly altered by the new position statements, prior ISCD official positions remain in force. This update reflects increased consideration of the clinical context prompting repeat examination. Follow-up DXA should be performed with pre-defined objectives when the results would have an impact on patient management. Testing intervals should be individualized according to the patient's age, sex, fracture risk and treatment history. Incident fractures and therapeutic approach are key considerations. Appropriately ordered and interpreted follow-up DXA examinations support diagnostic and therapeutic decision making, thereby contributing to excellent clinical care. Future research should address the complementary roles of clinical findings, imaging and laboratory testing to guide management.

Fracture discrimination capability of ulnar flexural rigidity measured via Cortical Bone Mechanics Technology: study protocol for The STRONGER Study

Osteoporosis is characterized by low bone mass and structural deterioration of bone tissue, which leads to bone fragility (ie, weakness) and an increased risk for fracture. The current standard for assessing bone health and diagnosing osteoporosis is DXA, which quantifies areal BMD, typically at the hip and spine. However, DXA-derived BMD assesses only one component of bone health and is notably limited in evaluating the bone strength, a critical factor in fracture resistance. Although multifrequency vibration analysis can quickly and painlessly assay bone strength, there has been limited success in advancing a device of this nature. Recent progress has resulted in the development of Cortical Bone Mechanics Technology (CBMT), which conducts a dynamic 3-point bending test to assess the flexural rigidity (EI) of ulnar cortical bone. Data indicate that ulnar EI accurately estimates ulnar whole bone strength and provides unique and independent information about cortical bone compared to DXA-derived BMD. Consequently, CBMT has the potential to address a critical unmet need: Better identification of patients with diminished bone strength who are at high risk of experiencing a fragility fracture. However, the clinical utility of CBMT-derived EI has not yet been demonstrated. We have designed a clinical study to assess the accuracy of CBMT-derived ulnar EI in discriminating post-menopausal women who have suffered a fragility fracture from those who have not. These data will be compared to DXA-derived peripheral and central measures of BMD obtained from the same subjects. In this article, we describe the study protocol for this multi-center fracture discrimination study (The STRONGER Study).

Fracture risk prediction in old Chinese people-a narrative review

With aging, the burden of osteoporotic fracture (OF) increases substantially, while China is expected to carry the greatest part in the future. The risk of fracture varies greatly across racial groups and geographic regions, and systematically organized evidence on the potential predictors for fracture risk is needed for Chinese. This review briefly introduces the epidemiology of OF and expands on the predictors and predictive tools for the risk of OF, as well as the challenges for their potential translation in the old Chinese population. There are regional differences of fracture incidence among China. The fracture incidences in Hong Kong and Taiwan have decreased in recent years, while it is still increasing in mainland China. Although the application of dual-energy X-ray absorptiometry (DXA) is limited among old Chinese in the mainland, bone mineral density (BMD) by DXA has a predictive value similar to that worldwide. Other non-DXA modalities, especially heel QUS, are helpful in assessing bone health. The fracture risk assessment tool (FRAX) has a good discrimination ability for OFs, especially the FRAX with BMD. And some clinical factors have added value to FRAX, which has been verified in old Chinese. In addition, although the application of the osteoporosis self-assessment tool for Asians (OSTA) in Chinese needs further validation, it may help identify high-risk populations in areas with limited resources. Moreover, the translation use of the muscle quality and genetic or serum biomarkers in fracture prediction needs further works. More applicable and targeted fracture risk predictors and tools are still needed for the old Chinese population.

An observational study of the radiofrequency echographic multi-spectrometry (REMS)-based fragility score of the lumbar spine and total fracture risk at 5 years in women

A novel fragility score (FS) parameter, obtained during radiofrequency echographic multi-spectrometry (REMS), was developed to estimate the ultrasound-based skeletal fragility. The aim of our study is to assess the REMS-based FS of the lumbar spine (LS) among the Bulgarian women and to compare their characteristics acquired with REMS between fracture risk classes corresponding to a total fracture risk at 5 years for major osteoporotic fractures (MOF). A total of 100 Bulgarian women, who underwent a screening for osteoporotic fracture risk using the REMS technology, were included in a prospective observational study. The mean age was 60 years (years) ± 13.9 standard deviations. We assessed the FS of the LS and for each subject. The fracture risk class (R1-R7) was identified using a table combining measured REMS T score and FS values. The mean FS was 36.9 ± 17.4 SD (range: 18.5-84.3). Twelve subjects (12%) were classified into the R6 group, twenty-three (23%) into the R5, sixty-one (61%) into R4, and four (4%) into R3. Statistical analysis showed significant difference in age, height, BMD, T score, Z score, age of menopause, FRAX for MOF, and FRAX for hip fractures between the risk class groups. This is the first study which showed the REMS-based FS of the lumbar spine among the Bulgarian women. T score alone is not a good predictor of fractures. Our study showed that its use in combination with the fragility score obtained during REMS offers a robust assessment of the fracture risk at 5 years for MOF.

A genome-wide genomic score added to standard recommended stratification tools does not improve the identification of patients with very low bone mineral density

The role of integrating genomic scores (GSs) needs to be assessed. Adding a GS to recommended stratification tools does not improve the prediction of very low bone mineral density. However, we noticed that the GS performed equally or above individual risk factors in discrimination.

PURPOSE

We aimed to investigate whether adding a genomic score (GS) to recommended stratification tools improves the discrimination of participants with very low bone mineral density (BMD).

METHODS

BMD was measured in three thoracic vertebrae using CT. All participants provided information on standard osteoporosis risk factors. GSs and FRAX scores were calculated. Participants were grouped according to mean BMD into very low (<80 mg/cm3), low (80-120 mg/cm3), and normal (>120 mg/cm3) and according to the Bone Health and Osteoporosis Foundation recommendations for BMD testing into an "indication for BMD testing" and "no indication for BMD testing" group. Different models were assessed using the area under the receiver operating characteristics curves (AUC) and reclassification analyses.

RESULTS

In the total cohort (n=1421), the AUC for the GS was 0.57 (95% CI 0.52-0.61) corresponding to AUCs for osteoporosis risk factors. In participants without indication for BMD testing, the AUC was 0.60 (95% CI 0.52-0.69) above or equal to AUCs for osteoporosis risk factors. Adding the GS to a clinical risk factor (CRF) model resulted in AUCs not statistically significant from the CRF model. Using probability cutoff values of 6, 12, and 24%, we found no improved reclassification or risk discrimination using the CRF-GS model compared to the CRF model.

CONCLUSION

Our results suggest adding a GS to a CRF model does not improve prediction. However, we noticed that the GS performed equally or above individual risk factors in discrimination. Clinical risk factors combined showed superior discrimination to individual risk factors and the GS, underlining the value of combined CRFs in routine clinics as a stratification tool.

The correlation between osteoporotic vertebrae fracture risk and bone mineral density measured by quantitative computed tomography and dual energy X-ray absorptiometry: a systematic review and meta-analysis

This paper presents a comparison of quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) in osteoporosis with vertebral fracture and osteoporosis without fracture. It has been proved that the volumetric bone mineral density (vBMD) measured by QCT exhibits a stronger correlation with fracture risk than areal bone mineral density (aBMD) measured by DXA.

PURPOSE

This study aims to systematically evaluate the ability of QCT and DXA to distinguish between osteoporosis with vertebral fracture and osteoporosis without fracture according to vBMD and aBMD.

METHODS

We conducted a primary literature search of the online databases up to 3 July, 2022, in both English and Chinese publications, combining synonyms for "QCT", "DXA" and "osteoporosis". The Newcastle-Ottawa scale (NOS) was employed to evaluate the quality of the selected articles. vBMD obtained through QCT and aBMD obtained through DXA were extracted, and were analyzed by Review Manager 5.4 and RStudio.

RESULTS

Six studies with 610 individuals aged 45 to 90, of which 179 had vertebral fractures, were included in the final analysis. The weighted mean difference (WMD) between osteoporosis with vertebral fracture and osteoporosis without fracture for vBMD was - 27.08 (95% CI  - 31.24 to  - 22.92), while for aBMD was - 0.05 (95% CI - 0.08 to - 0.03).

CONCLUSIONS

Both vBMD detected by QCT and aBMD detected by DXA could discriminate fracture status in the spine, and vBMD performed a stronger correlation with fracture risk.

TRIAL REGISTRATION

PROSPERO 2022 CRD42022349185.

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.

Pediatric and Adult Fracture Incidence: A Decreasing Trend With Increasing Hospital Admissions

Large-scale studies examining fracture trends and epidemiological data are lacking. The purpose of this study was to evaluate the incidence of fractures presenting to US emergency departments using the National Electronic Injury Surveillance System. A total of 7,109,078 pediatric and 13,592,548 adult patients presenting to US emergency departments with a fracture between 2008 and 2017 were analyzed for patterns. Fractures accounted for 13.9% of pediatric injuries and 15% of adult injuries. Among children, fracture incidence was highest in the group 10 to 14 years old and most frequently involved the forearm (19.0%). Fracture incidence was highest in adults 80 years and older and most frequently involved the lower trunk (16.2%). On average, the rate of pediatric fractures decreased by 2.34% per year (95% CI, 0.25% increase to 4.88% decrease; P=.0757). Among adults, fracture incidence increased 0.33% per year (95% CI, 2.34% decrease to 2.85% increase; P=.7892). This change was significantly different between the pediatric and adult populations (P=.0152). There was an increase in the annual proportion of adults with fractures who were admitted (odds ratio per 1-year increase, 1.05; 95% CI, 1.03-1.07; P<.0001). There was no change in the proportion of pediatric patients with fractures who were admitted (odds ratio, 1.02; 95% CI, 0.99-1.05; P=.0606). The incidence of fractures decreased in pediatric patients yet was relatively stable in adult patients. Conversely, the proportion of patients with fractures who were admitted increased, particularly among adults. These findings may suggest that less severe fractures are presenting elsewhere, falsely inflating the observed rise in admissions. [Orthopedics. 2023;46(6):e369-e375.].

Photon-Counting CT Material Decomposition in Bone Imaging

The accurate screening of osteoporosis is important for identifying persons at risk. The diagnosis of bone conditions using dual X-ray absorptiometry is limited to extracting areal bone mineral density (BMD) and fails to provide any structural information. Computed tomography (CT) is excellent for morphological imaging but not ideal for material quantification. Advanced photon-counting detector CT (PCD-CT) possesses high spectral sensitivity and material decomposition capabilities to simultaneously determine qualitative and quantitative information. In this study, we explored the diagnostic utility of PCD-CT to provide high-resolution 3-D imaging of bone microarchitecture and composition for the sensitive diagnosis of bone in untreated and ovariectomized rats. PCD-CT accurately decomposed the calcium content within hydroxyapatite phantoms (r = 0.99). MicroCT analysis of tibial bone revealed significant differences in the morphological parameters between the untreated and ovariectomized samples. However, differences in the structural parameters of the mandible between the treatment groups were not observed. BMD determined with microCT and calcium concentration decomposed using PCD-CT differed significantly between the treatment groups in both the tibia and mandible. Quantitative analysis with PCD-CT is sensitive in determining the distribution of calcium and water components in bone and may have utility in the screening and diagnosis of bone conditions such as osteoporosis.

Effects of an mHealth physical activity intervention to prevent osteoporosis in premenopausal women. A randomized controlled trial

OBJECTIVES

It is critical to develop prevention strategies for osteoporosis that reduce the burden fractures place on individuals and health systems. This study evaluated the effects of an mHealth intervention that delivered and monitored a non-supervised exercise program on bone mineral density (BMD).

DESIGN

Randomized controlled trial.

METHODS

60 premenopausal women aged 35-50 years were divided into an intervention group (IG) and a control group (CG). The IG followed a 6-month intervention aimed at increasing osteogenic physical activity, guided by two daily goals: walking at least 10,000 steps and completing 60 impacts over 4 g of acceleration. These goals were monitored using a wearable accelerometer linked to an mHealth app. The CG maintained their regular lifestyle and wore the accelerometer without feedback. BMD was estimated using dual-energy X-ray absorptiometry (DXA) scans at baseline and after 6 months, with group-by-time analyses conducted using ANCOVA. The intervention's impact on physical fitness and activity habits was also evaluated.

RESULTS

46 participants completed the study (IG = 24; CG = 22). The IG showed significant improvements compared to the CG in femoral neck BMD (IG: +0.003 ± 0.029 g/cm2 vs CG: -0.027 ± 0.031 g/cm2), trochanter BMD (IG: +0.004 ± 0.023 g/cm2 vs CG: -0.026 ± 0.030 g/cm2), and total hip BMD (IG: +0.006 ± 0.043 g/cm2 vs CG: -0.040 ± 0.048 g/cm2). The IG also demonstrated significant improvements in physical fitness measures, including peak torque and power at various speeds and positions. No adverse events related to the intervention were reported.

CONCLUSIONS

This non-supervised physical activity intervention delivered by wearable-technology and an mHealth app was effective in improving BMD, suggesting its potential for osteoporosis prevention.

High-resolution peripheral quantitative computed tomography: research or clinical practice?

High-resolution peripheral quantitative CT (HR-pQCT) is a low-dose three-dimensional imaging technique, originally developed for in vivo assessment of bone microarchitecture at the distal radius and tibia in osteoporosis. HR-pQCT has the ability to discriminate trabecular and cortical bone compartments, providing densitometric and structural parameters. At present, HR-pQCT is mostly used in research settings, despite evidence showing that it may be a valuable tool in osteoporosis and other diseases. This review summarizes the main applications of HR-pQCT and addresses the limitations that currently prevent its integration into routine clinical practice. In particular, the focus is on the use of HR-pQCT in primary and secondary osteoporosis, chronic kidney disease (CKD), endocrine disorders affecting bone, and rare diseases. A section on novel potential applications of HR-pQCT is also present, including assessment of rheumatic diseases, knee osteoarthritis, distal radius/scaphoid fractures, vascular calcifications, effect of medications, and skeletal muscle. The reviewed literature seems to suggest that a more widespread implementation of HR-pQCT in clinical practice would offer notable opportunities. For instance, HR-pQCT can improve the prediction of incident fractures beyond areal bone mineral density provided by dual-energy X-ray absorptiometry. In addition, HR-pQCT may be used for the monitoring of anti-osteoporotic therapy or for the assessment of mineral and bone disorder associated with CKD. Nevertheless, several obstacles currently prevent a broader use of HR-pQCT and would need to be targeted, such as the small number of installed machines worldwide, the uncertain cost-effectiveness, the need for improved reproducibility, and the limited availability of reference normative data sets.

[Diagnosis and treatment of osteoporosis in patients with chronic kidney disease : Joint guidelines of the Austrian Society for Bone and Mineral Research (ÖGKM), the Austrian Society of Physical and Rehabilitation Medicine (ÖGPMR) and the Austrian Society of Nephrology (ÖGN)]

DEFINITION AND EPIDEMIOLOGY

Chronic kidney disease (CKD): abnormalities of kidney structure or function, present for over 3 months. Staging of CKD is based on GFR and albuminuria (not graded). Osteoporosis: compromised bone strength (low bone mass, disturbance of microarchitecture) predisposing to fracture. By definition, osteoporosis is diagnosed if the bone mineral density T‑score is ≤ -2.5. Furthermore, osteoporosis is diagnosed if a low-trauma (inadequate trauma) fracture occurs, irrespective of the measured T‑score (not graded). The prevalence of osteoporosis, osteoporotic fractures and CKD is increasing worldwide (not graded). PATHOPHYSIOLOGY, DIAGNOSIS AND TREATMENT OF CHRONIC KIDNEY DISEASE-MINERAL AND BONE DISORDER (CKD-MBD): Definition of CKD-MBD: a systemic disorder of mineral and bone metabolism due to CKD manifested by either one or a combination of the following: abnormalities of calcium, phosphorus, PTH, or vitamin D metabolism; renal osteodystrophy; vascular calcification (not graded). Increased, normal or decreased bone turnover can be found in renal osteodystrophy (not graded). Depending on CKD stage, routine monitoring of calcium, phosphorus, alkaline phosphatase, PTH and 25-OH-vitamin D is recommended (2C). Recommendations for treatment of CKD-MBD: Avoid hypercalcemia (1C). In cases of hyperphosphatemia, lower phosphorus towards normal range (2C). Keep PTH within or slightly above normal range (2D). Vitamin D deficiency should be avoided and treated when diagnosed (1C).

DIAGNOSIS AND RISK STRATIFICATION OF OSTEOPOROSIS IN CKD

Densitometry (using dual X‑ray absorptiometry, DXA): low T‑score correlates with increased fracture risk across all stages of CKD (not graded). A decrease of the T‑score by 1 unit approximately doubles the risk for osteoporotic fracture (not graded). A T-score ≥ -2.5 does not exclude osteoporosis (not graded). Bone mineral density of the lumbar spine measured by DXA can be increased and therefore should not be used for the diagnosis or monitoring of osteoporosis in the presence of aortic calcification, osteophytes or vertebral fracture (not graded). FRAX can be used to aid fracture risk estimation in all stages of CKD (1C). Bone turnover markers can be measured in individual cases to monitor treatment (2D). Bone biopsy may be considered in individual cases, especially in patients with CKD G5 (eGFR < 15 ml/min/1.73 m2) or CKD 5D (dialysis).

SPECIFIC TREATMENT OF OSTEOPOROSIS IN PATIENTS WITH CKD

Hypocalcemia should be treated and serum calcium normalized before initiating osteoporosis therapy (1C). CKD G1-G2 (eGFR ≥ 60 ml/min/1.73 m2): treat osteoporosis as recommended for the general population (1A). CKD G3-G5D (eGFR < 60 ml/min/1.73 m2 to dialysis): treat CKD-MBD first before initiating osteoporosis treatment (2C). CKD G3 (eGFR 30-59 ml/min/1.73 m2) with PTH within normal limits and osteoporotic fracture and/or high fracture risk according to FRAX: treat osteoporosis as recommended for the general population (2B). CKD G4-5 (eGFR < 30 ml/min/1.73 m2) with osteoporotic fracture (secondary prevention): Individualized treatment of osteoporosis is recommended (2C). CKD G4-5 (eGFR < 30 ml/min/1.73 m2) and high fracture risk (e.g. FRAX score > 20% for a major osteoporotic fracture or > 5% for hip fracture) but without prevalent osteoporotic fracture (primary prevention): treatment of osteoporosis may be considered and initiated individually (2D). CKD G4-5D (eGFR < 30 ml/min/1.73 m2 to dialysis): Calcium should be measured 1-2 weeks after initiation of antiresorptive therapy (1C).

PHYSICAL MEDICINE AND REHABILITATION

Resistance training prioritizing major muscle groups thrice weekly (1B). Aerobic exercise training for 40 min four times per week (1B). Coordination and balance exercises thrice weekly (1B). Flexibility exercise 3-7 times per week (1B).