Trabecular bone score (TBS) predicts vertebral fractures in Japanese women over 10 years independently of bone density and prevalent vertebral deformity: the Japanese Population-Based Osteoporosis (JPOS) cohort study

Can TBS reference values be a valid indicator for clinical vertebral fracture? A cross-sectional study

INTRODUCTION

Trabecular bone score (TBS) is partially independent of fracture risk. Reference values for TBS have not been established in official guidelines, and thus clinicians often have difficulty interpreting TBS results. This study aimed to investigate whether reference values for TBS could be a valid indicator for clinical vertebral fracture (CVF).

MATERIALS AND METHODS

This cross-sectional study involved 231 women with CVF and 563 women without CVF aged 60-90 years who underwent dual-energy X-ray absorptiometry during 2019-2023. They were divided into osteoporosis, osteopenia, and normal groups according to bone mineral density of the lumbar spine. Reference values for TBS were defined as low (≤ 1.23), intermediate (1.23-1.31), and high (≥ 1.31).

RESULTS

Among patients without anti-osteoporosis treatment (n = 476), the proportion with low TBS was 36.7% in the CVF group and 10.7% in the control group. The proportion with CVF was higher in the low TBS group than in the intermediate and high TBS groups, especially in the osteoporosis group (p < 0.001). The odds ratio for CVF was higher in the low TBS group than in the intermediate and high especially in patients with normal BMD and osteoporosis. The TBS cut-off values for incidence of CVF in the osteoporosis, osteopenia, and normal groups were 1.224, 1.319, and 1.322, respectively.

CONCLUSIONS

The reference value for low TBS (≤ 1.23) was useful as an indicator for CVF, especially in patients with osteoporosis. It is expected that reference values for TBS will be established in official guidelines in the future.

Clinical Use of Trabecular Bone Score: The 2023 ISCD Official Positions

Osteoporosis can currently be diagnosed by applying the WHO classification to bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA). However, skeletal factors other than BMD contribute to bone strength and fracture risk. Lumbar spine TBS, a grey-level texture measure which is derived from DXA images has been extensively studied, enhances fracture prediction independent of BMD and can be used to adjust fracture probability from FRAX® to improve risk stratification. The purpose of this International Society for Clinical Densitometry task force was to review the existing evidence and develop recommendations to assist clinicians regarding when and how to perform, report and utilize TBS. Our review concluded that TBS is most likely to alter clinical management in patients aged ≥ 40 years who are close to the pharmacologic intervention threshold by FRAX. The TBS value from L1-L4 vertebral levels, without vertebral exclusions, should be used to calculate adjusted FRAX probabilities. L1-L4 vertebral levels can be used in the presence of degenerative changes and lumbar compression fractures. It is recommended not to report TBS if extreme structural or pathological artifacts are present. Monitoring and reporting TBS change is unlikely to be helpful with the current version of the TBS algorithm. The next version of TBS software will include an adjustment based upon directly measured tissue thickness. This is expected to improve performance and address some of the technical factors that affect the current algorithm which may require modifications to these Official Positions as experience is acquired with this new algorithm.

Injection of a PMMA-doped MSC spheroid gel for the treatment of painful osteoporotic vertebral compression fractures

We aimed to develop a biocompatible treatment to overcome the limitations of polymethyl methacrylate (PMMA) vertebroplasty for osteoporotic compression fracture patients. We synthesized an injectable hydrogel containing PMMA. Mesenchymal stem cell (MSC) spheroids were included in the injectable PMMA-doped gel (= PMMA-doped spheroid gel). In vitro, the osteogenic/anti-inflammatory effects of the embedded spheroids were investigated by the quantitative real-time polymerase chain reaction method. In vivo, we used ovariectomy (OVX)-induced osteoporotic rats with injured femurs to investigate the pain-relief effects. The OVX rats were divided into four groups according to the materials injected (non, PMMA, PMMA gel, and PMMA-spheroid gel) into the lesion. The immunofluorescence (IF) intensity levels of painful markers in dorsal root ganglia (DRG) were measured. In vitro, a volumetric ratio of the gel of 8 (gel):2 (PMMA) was non-cytotoxic for MSCs and promoted the expression of osteogenic/anti-inflammatory markers. In vivo, the values of several bone parameters in the PMMA-doped spheroid gel group showed remarkable increases compared to those in the PMMA group. In addition, the IF intensity levels of the painful markers were noticeably decreased in the PMMA-spheroid gel group. We, therefore, suggest that this treatment can be useful for osteoporotic vertebral compression fracture patients.

Cost-effectiveness of opportunistic QCT-based osteoporosis screening for the prediction of incident vertebral fractures

Objectives

Opportunistic quantitative computed tomography (oQCT) derived from non-dedicated routine CT has demonstrated high accuracy in diagnosing osteoporosis and predicting incident vertebral fractures (VFs). We aimed to investigate the cost-effectiveness of oQCT screening compared to dual-energy X-ray absorptiometry (DXA) as the standard of care for osteoporosis screening.

Methods

Three screening strategies ("no osteoporosis screening", "oQCT screening", and "DXA screening") after routine CT were simulated in a state-transition model for hypothetical cohorts of 1,000 patients (women and men aged 65 years) over a follow-up period of 5 years (base case). The primary outcomes were the cumulative costs and the quality-adjusted life years (QALYs) estimated from a U.S. health care perspective for the year 2022. Cost-effectiveness was assessed based on a willingness-to-pay (WTP) threshold of $70,249 per QALY. The secondary outcome was the number of prevented VFs. Deterministic and probabilistic sensitivity analyses were conducted to test the models' robustness.

Results

Compared to DXA screening, oQCT screening increased QALYs in both sexes (additional 2.40 per 1,000 women and 1.44 per 1,000 men) and resulted in total costs of $3,199,016 and $950,359 vs. $3,262,934 and $933,077 for women and men, respectively. As a secondary outcome, oQCT screening prevented 2.6 and 2.0 additional VFs per 1,000 women and men, respectively. In the probabilistic sensitivity analysis, oQCT screening remained cost-effective in 88.3% (women) and 90.0% (men) of iterations.

Conclusion

oQCT screening is a cost-effective ancillary approach for osteoporosis screening and has the potential to prevent a substantial number of VFs if considered in daily clinical practice.

Feasibility of Bone Mineral Density and Bone Microarchitecture Assessment Using Deep Learning With a Convolutional Neural Network

OBJECTIVES

We evaluated the feasibility of using deep learning with a convolutional neural network for predicting bone mineral density (BMD) and bone microarchitecture from conventional computed tomography (CT) images acquired by multivendor scanners.

METHODS

We enrolled 402 patients who underwent noncontrast CT examinations, including L1-L4 vertebrae, and dual-energy x-ray absorptiometry (DXA) examination. Among these, 280 patients (3360 sagittal vertebral images), 70 patients (280 sagittal vertebral images), and 52 patients (208 sagittal vertebral images) were assigned to the training data set for deep learning model development, the validation, and the test data set, respectively. Bone mineral density and the trabecular bone score (TBS), an index of bone microarchitecture, were assessed by DXA. BMDDL and TBSDL were predicted by deep learning with a convolutional neural network (ResNet50). Pearson correlation tests assessed the correlation between BMDDL and BMD, and TBSDL and TBS. The diagnostic performance of BMDDL for osteopenia/osteoporosis and that of TBSDL for bone microarchitecture impairment were evaluated using receiver operating characteristic curve analysis.

RESULTS

BMDDL and BMD correlated strongly (r = 0.81, P < 0.01), whereas TBSDL and TBS correlated moderately (r = 0.54, P < 0.01). The sensitivity and specificity of BMDDL for identifying osteopenia or osteoporosis were 93% and 90%, and 100% and 94%, respectively. The sensitivity and specificity of TBSDL for identifying patients with bone microarchitecture impairment were 73% for all values.

CONCLUSIONS

The BMDDL and TBSDL derived from conventional CT images could identify patients who should undergo DXA, which could be a gatekeeper tool for detecting latent osteoporosis/osteopenia or bone microarchitecture impairment.

Prevalence of osteoporosis and incidence of related fractures in developed economies in the Asia Pacific region: a systematic review

Robust data on osteoporosis in the Asia Pacific region could improve healthcare decision-making. Osteoporosis affects 10-30% of women aged 40 + , and up to 10% of men in 7 developed economies in Asia Pacific. Fractures affect 500-1000 adults aged 50 + per 100,000 person-years. Policymakers and clinicians must address this problem.

PURPOSE

Osteoporosis and associated fractures result in considerable morbidity, loss of productivity, early mortality, and increased healthcare expenses. Many countries in the Asia Pacific (AP) region, especially middle- and higher-income economies, are faced with aging and increasingly sedentary populations. It is critical to consolidate and analyze the available information on the prevalence and incidence of the disease in these countries.

METHODS

We systematically reviewed articles and gray literature for Australia, China, Hong Kong, Japan, Singapore, South Korea, and Taiwan. We searched PubMed, ScienceDirect, JSTOR, Cochrane, Google Scholar, and other databases for data published 2009-2018. We included articles with prevalence or incidence estimates for adults with osteoporosis or related fractures.

RESULTS

All locations had data available, but of widely varying quantity and quality. Most estimates for osteoporosis prevalence ranged from 10 to 30% for women ages 40 and older, and up to 10% for men. Osteoporotic fracture incidence typically ranged between 500 and 1000 per 100,000 person-years among adults aged 50 and older. Both outcomes typically increased with age and were more common among women.

CONCLUSION

Osteoporosis and associated fractures affect significant portions of the adult population in developed economies in the AP region. Governments and healthcare systems must consider how best to prevent and diagnose osteoporosis, and manage affected individuals, to reduce healthcare costs and mortality associated with fractures.

Reference Value of Dual X-Ray Absorptiometry-Derived Lumbar Spine Trabecular Bone Score in the Thai Population

INTRODUCTION

Little is known about the normative values of trabecular bone score (TBS) in Thailand. We aimed to provide reference values of dual-energy x-ray absorptiometry (DXA)-derived lumbar spine TBS in Thai community-dwelling adults of varying ages.

METHODOLOGY

Bone density studies of participants aged 20-90 years who underwent bone mineral density (BMD) testing at Srinagarind Hospital, Kohn Kaen, Thailand were reviewed. DXA studies were performed using a narrow fan-beam bone densitometer. Lumbar spine TBS for each of the L1-L4 vertebra was obtained using the iNsight software. Mean TBS (L1-L4 TBS) was calculated. This study was approved by the institutional research ethics committee (HE581241).

RESULTS

A total of 1372 participants were included. The mean ± SD age was 57.25 ± 17.35 years and 799 (58.2%) were female. There were 476 (34.7%) and 243 (17.7%) participants with osteopenia (T-score -1.0 to -2.5) and osteoporosis (T-score ≤-2.5) of the lumbar spine. Age and sex stratified analysis of L1-L4 TBS revealed peak TBS among females aged 30-49 years (mean ± SD: 1.42 ± 0.08) and males aged 30-59 years (mean ± SD: 1.42 ± 0.09). The rate of L1-L4 TBS reduction from ages 30 to 90 year is 13.4% (0.27%/year) for females and 5.6% (0.11%/year) for males.

CONCLUSION

This is the first study reporting a normative database for DXA derived TBS in Thai community-dwelling population. We found that TBS decreased with age at the rate of approximately 0.27%/year for females and 0.11%/year for males.

Trabecular Bone Score as a Risk Factor of Major Osteoporotic Fracture in Postmenopausal Women: The First Study in Thailand

OBJECTIVES

To compare the trabecular bone score (TBS) between Thai postmenopausal women with and without major osteoporotic fracture, and to determine whether TBS is associated with fracture risk.

METHODS

All postmenopausal women sent for dual-energy X-ray absorptiometry (DXA) at the Police General Hospital were retrospectively recruited. The hospital's online database and radiographs were reviewed to collect information on underlying disease, medication, previous fractures, bone mineral density, and trabecular bone score. Patients with anti-osteoporotic medication use, skeletal malignancy, fracture from high-energy trauma, and uninterpretable DXA images were excluded.

RESULTS

A total of 407 Thai postmenopausal women were enrolled. They were divided into 292 women without fractures and 115 women with major osteoporotic fractures. The fracture group was older (73.36 ± 9.95 vs. 66.00 ± 8.58, P < 0.001) and had lower serum 25-hydroxyvitamin D levels (23.28 ± 9.09 vs. 26.44 ± 9.20, P = 0.023). The mean TBS was lower in the fracture group, compared to the non-fracture group (1.244 ± 0.101 vs. 1.272 ± 0.099, P = 0.011). The subgroup analysis resulted in noticeably lower TBS in spine fracture, but not other fracture sites. The odds ratio of fracture was 1.355 (P = 0.013) for a decrease in one standard deviation of TBS.

CONCLUSIONS

TBS was significantly lower in postmenopausal women having fractures with an odd ratio of 1.355 (P = 0.013) per SD decrease in TBS. Categorizing by fracture sites, TBS was only found to be noticeably lower in the lumbar spine despite similar lumbar spine bone mineral density.

Update on trabecular bone score

Trabecular bone score (TBS) is an indirect and noninvasive measure of bone quality. A low TBS indicates degraded bone microarchitecture, predicts osteoporotic fracture, and is partially independent of clinical risk factors and bone mineral density (BMD). There is substantial evidence supporting the use of TBS to assess vertebral, hip, and major osteoporotic fracture risk in postmenopausal women, as well as to assess hip and major osteoporotic fracture risk in men aged > 50 years. TBS complements BMD information and can be used to adjust the FRAX (Fracture Risk Assessment) score to improve risk stratification. While TBS should not be used to monitor antiresorptive therapy, it may be potentially useful for monitoring anabolic therapy. There is also a growing body of evidence indicating that TBS is particularly useful as an adjunct to BMD for fracture risk assessment in conditions associated with increased fracture risk, such as type-2 diabetes, chronic corticosteroid excess, and other conditions wherein BMD readings are often misleading. The interference of abdominal soft tissue thickness (STT) on TBS should also be considered when interpreting these findings because image noise can impact TBS evaluation. A new TBS software version based on an algorithm that accounts for STT rather than BMI seems to correct this technical limitation and is under development. In this paper, we review the current state of TBS, its technical aspects, and its evolving role in the assessment and management of several clinical conditions.

Identifying vertebral fractures in the Japanese population using the trabecular bone score: a cross-sectional study

Background

The trabecular bone score (TBS) is reported to be an independent predictor of fracture risk in patients with primary or secondary osteoporosis. However, there have been few reports on its use in the Japanese population. This study aimed to investigate the risk factors for vertebral fracture in the Japanese population and to evaluate the usefulness of TBS.

Methods

This cross-sectional study involved 279 patients aged 60–90 years in whom bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). TBS was calculated based on the DXA scans. The presence or absence of vertebral fractures was assessed from T11 to L5. The patients were divided into those with vertebral fractures (VF group, n = 104) and those without vertebral fractures (non-VF group, n = 175).

Results

Of the 104 patients in the VF group, 75 had 1 vertebral fracture and 29 had 2 or more fractures. The mean TBS was 1.28 in the VF group and 1.35 in the non-VF group (p < 0.001). The mean BMD values at the lumbar spine and femoral neck were lower in the VF group (p < 0.001). The areas under the receiver-operating characteristic curve for incidence of vertebral fractures were 0.700, 0.737, and 0.689 for TBS, lumbar spine BMD, and femoral neck BMD, respectively. Multiple logistic regression analysis identified lumbar spine BMD, TBS, and female sex as significant risk factors for vertebral fractures. The proportion of patients in the group with osteoporosis or osteopenia who had vertebral fractures was higher in those with a low TBS (≤ 1.23) than in those with a non-low TBS (> 1.23).

Conclusion

TBS was a significant indicator of vertebral fractures in the Japanese population and might contribute to identifying patients with vertebral fractures, particularly those with osteopenia who need pharmacologic therapy.

Spine Fragility Fracture Prediction Using TBS and BMD in Postmenopausal Women: A Bayesian Approach

The trabecular bone score (TBS) estimates bone microarchitecture and can be used to evaluate the risk of osteoporotic fractures independently of bone mineral density (BMD). In this retrospective case-control study, we tested and compared the ability of TBS and lumbar spine BMD (LS-BMD) to predict vertebral fragility fractures. The inclusion criteria were female sex, age range 50-90 years, menopause, and clinical risk factors for osteoporosis. Patients with secondary osteoporosis were excluded. LS-BMD and TBS were measured at the L1-L4 vertebral level. The ability of the two diagnostic systems in predicting vertebral fragility fractures was assessed by combining LS-BMD and TBS according to the Bayesian "OR rule" (the diagnosis is negative only for those negative for both tests, and it is positive for those who were positive for at least one test) or to the "AND rule" (the diagnosis is positive only for those positive to both tests and is negative for those negative for at least one test). Of the 992 postmenopausal women included, 86 had a documented vertebral fragility fracture. At the cutoff value used in the present study, the TBS and LS-BMD showed a similar diagnostic ability to predict vertebral fragility fractures, having positive predictive values (PPV) of, respectively, 13.19% and 13.24%. Negative predictive values (NPV) were, respectively, 95.40% and 94.95%. Compared to that of each single diagnostic system, the "OR-rule" significantly increased the NPV to 97.89%, while no statistically significant differences were found by using the "AND-rule". In conclusion, the present study highlights the possibility that combining LS-BMD and TBS could improve their predictive ability in diagnosing vertebral fragility fractures, and that there is a significant probability of absence of fractures in women who test negative to both diagnostic systems.

Spine trabecular bone scores and bone mineral density of postmenopausal Taiwanese women

OBJECTIVES

The aims of the study were to determine the mean trabecular bone score (TBS) of postmenopausal Taiwanese women and to analyze the value of TBS in predicting osteoporosis.

METHODS

A total of 1,915 postmenopausal women with lumbar spine and hip bone mineral density (BMD) and spine TBS were enrolled from a single medical center into this study. The women's BMD and TBS were measured using dual x-ray absorptiometry (Discovery Wi; Hologic, Bedford, Mass) and iNsight software (Med-Imaps SASU, Merignac, France), respectively. The women's demographic characteristics; lumbar spine, total hip, and femoral neck BMD; and lumbar spine TBS were recorded, and correlations among the parameters were identified using a 2-tailed Pearson test, in which a P value less than 0.05 was considered statistically significant. We developed simple linear regression models to represent changes related to TBS and performed an analysis of variance on the selected variables.

RESULTS

The average age of the women was 62.5 ± 9.1 years (range, 25.7-93.7 years). The mean TBS was 1.300 ± 0.086 (range, 1.015-1.596). The TBS was weakly and negatively correlated with body mass index ( r = -0.078) and moderately and positively correlated with the lumbar spine BMD ( r = 0.619). The patients' lowest BMD values among those measured at multiple sites revealed a higher rate of osteoporosis (32.5%) than those measured at individual sites. Degraded TBS were noted in 21.2% of the participants, and a combination of BMD and TBS results predicted more individuals (7.8%) at a high risk of fracture than did the BMD result only. The rates of both osteoporosis and degraded TBS increased with age.

CONCLUSIONS

Bone mineral density and TBS can be used in combination to predict osteoporosis in a greater number of postmenopausal Taiwanese women. Because the incidence of osteoporosis is the highest among older women, clinicians should pay careful attention to TBS degradation among older patients without low BMD.

Trabecular bone score as an additional therapeutic decision tool in osteoporosis and osteopenia

Objectives

To evaluate the role of trabecular bone score (TBS), in addition to bone mineral density (BMD), and to aid decision making to initiate anti-osteoporotic treatment in postmenopausal women with osteopenia.

Methods

TBS was assessed in a cohort of Thai postmenopausal women with BMD of femoral neck (FN), total hip (TH), and lumbar spine (LS) performed at the Police General Hospital, Bangkok, Thailand from July 2019 to October 2020. We retrospectively reviewed hospital database for underlying diseases, medication, and fractures, including relevant imaging and vertebral fracture assessment (VFA). Patients with previous osteoporosis treatment, skeletal malignancy, high-energy trauma, and uninterpretable BMD were excluded.

Results

In total there were 407 postmenopausal women, including 115 with osteoporotic fractures. The mean TBS of the cohort was 1.264 ± 0.005. The proportion of osteoporotic subjects ranged from 9.1% by TH BMD to 27.0% by lowest BMD. In fractured patients, 21.7%–54.8% were found to have osteoporosis while osteopenia was found in 37.4%–43.5%. Among subjects with osteopenia and degraded TBS, fractures ranged from 21.7 to 50.9%. Addition of osteopenic subjects with degraded microarchitecture yielded a significantly higher number of subjects eligible for treatment with 3.25-fold increase in non-fractured participants, and 7 to 11 additional osteopenic patients should be treated to detect 1 fracture.

Conclusions

Addition of TBS helped capturing osteopenic women with high risk of fracture. Decision to treat osteopenic women with degraded TBS increased the number of patients receiving treatment. We recommend evaluating TBS in osteopenic women without fractures to aid therapeutic decision on treatment initiation.

The Influence of Low Energy Availability on Bone Mineral Density and Trabecular Bone Microarchitecture of Pubescent Female Athletes: A Preliminary Study

The influence of low energy availability (LEA) on bone mineral density (BMD) and trabecular bone microarchitecture in pubescent female athletes is unclear. This study aimed to investigate the influence of LEA on BMD and trabecular bone microarchitecture in 21 pubescent female athletes (age, 12−15 years; 11 track and field athletes, 10 gymnasts). We used two indices to assess LEA: energy availability and the percent of ideal body weight. Dual-energy X-ray absorptiometry was used to obtain total body less head, lumbar spine BMD Z-scores, and lumbar trabecular bone scores (TBS). Pearson’s or Spearman’s correlation coefficients were used to assess the relationship among EA, percent of ideal body weight, and bone parameters. The threshold for statistical significance was set at p < 0.05. The percent of ideal body weight was significantly correlated with the BMD Z-scores of the total body less head (r = 0.61; p < 0.01), lumbar spine (r = 0.55; p < 0.01), and lumbar TBS (r = 0.47; p = 0.03). However, energy availability was not correlated with bone parameters. These findings suggest that screening for low ideal body weight may be a useful predictor of low BMD and insufficient trabecular bone microarchitecture in pubescent female athletes.

MRI-based vertebral bone quality score effectively reflects bone quality in patients with osteoporotic vertebral compressive fractures

OBJECTIVE

The present study is aimed to validate the ability of the vertebral bone quality (VBQ) score to evaluate bone quality in patients with osteoporotic vertebral compression fractures (OVCF) and to compare it with the ability of T-score by DXA. In addition, the sensitivity of VBQ score with cerebrospinal fluid (CSF) of L2 and L3 segments as baseline is evaluated.

METHODS

196 inpatients were collected and assigned into OVCF and Non-OVCF groups, respectively. For each patient, the VBQ score was calculated by the signal intensity of the L1-L4 vertebral bodies and CSF at L3 or L2 level from T1-weighted MRIs, while T-score from DXA was also obtained. The VBQ and T-score was compared between OVCF and non-OVCF groups, and among age groups. The OVCF ORs by VBQ score and T-score were calculated using logistic regression.

RESULTS

OVCF group was significantly different to the non-OVCF group in the T-score (- 2.9 vs. - 0.7) and VBQ score (4.0 vs. 3.5). VBQ score and T-score in patient aged 60-79 years old could indicate the bone quality, but only T-score in patients aged 50-59 years old. OVCF are associated with both higher VBQ score and lower T-score. The VBQ scores calculated by L2 CSF and L3 CSF were similar.

CONCLUSIONS

The VBQ score is an effective indicator of bone quality in OVCF patients and comparable to T-score, particularly in people over 60 years old. The VBQ score is not sensitive to CSF of different segments as a baseline.

Age-Related Changes in Trabecular Bone Score and Bone Mineral Density in Chinese Men: A Cross-Sectional and Longitudinal Study

Purpose

This study was designed to explore age-related changes in trabecular bone score (TBS) and bone mineral density (BMD) in Chinese men through cross-sectional and longitudinal studies.

Patients and Methods

We included adult men who had at least twice TBS and BMD examinations in our hospital between January 2013 and December 2020. All men were divided into an age subgroup per 10 years, comparing differences in baseline lumbar spine (LS) TBS and BMD at various parts between each age group and analyzing age-related changes in TBS and BMD during follow-up.

Results

Baseline data showed that in men aged 36 to 85 years, BMD in the hip region showed a decreasing trend with age (P for trend < 0.01). However, TBS reached a high value around the age of 50, after which it decreased with age (P for trend = 0.03). During a mean follow-up of 3 years, the average annual change rate at TBS was −0.17% in men aged 36 to 85 years, with the fastest decrease rate −1.08% at 66 to 75 years (P < 0.05). The mean annual rate of change in LS BMD in different age subgroups increased with age (P for trend = 0.001). There was no significant decrease in mean annual change in BMD in hip regions.

Conclusion

In men aged 36~85 years, the trend of TBS was inconsistent with BMD. Men experience a high value of LS TBS around age 50, later than the commonly believed age of peak BMD, which may reflect developmental differences between bone microstructure and bone minerals. The TBS may be used as a better indicator of changes in bone strength than BMD in adult men at short-term follow-up. The rapid loss of TBS at age 66 to 75 may have implications for the prevention and medication of osteoporosis in men.

Bone Mineral Density and Trabecular Bone Score in Predicting Vertebral Fractures in Male Employees of the Electricity Generating Authority of Thailand

PURPOSE

Osteoporotic VF is frequently asymptomatic and affects not only women but also men. Identifying patients at risk is essential for early management and prevention. BMD and the TBS are measurements of bone strength and trabecular microarchitecture, respectively. Their role in VF prediction in men is less well-studied. We determined the BMD and TBS predictive ability for osteoporotic VF in men.

METHODS

A total of 115 male participants of the Electricity Generating Authority of Thailand (EGAT) cohorts without a history of VF who completed the baseline BMD and TBS measurements in 2012 and a thoracolumbar spine radiograph in 2017 were recruited. The VF was assessed using the Genant semiquantitative method. Logistic regression analysis was performed to identify factors associated with the fracture. The area under the receiving operator curve (AUC) was analyzed to define VF predictive ability.

RESULTS

Forty subjects (34.78%) had VFs. The unadjusted relative risks (95% confidence interval) for VF for one standard deviation decrease in the TBS and low TBS were 1.319 (1.157-1.506) and 2.347 (1.496-3.682), respectively, and remained significant after BMD and age adjustment. For VF prediction, combined models had a greater AUC than models predicted from a single variable. The use of low TBS, femoral neck BMD, and age provided the best AUC (0.693).

CONCLUSION

BMD and the TBS could predict osteoporotic VF in male EGAT employees. The use of both BMD and the TBS in the VF prediction process improved predictive ability.

Usefulness of the Trabecular Bone Score in Assessing the Risk of Vertebral Fractures in Patients with Cirrhosis

The trabecular bone score (TBS), a surrogate measure of bone microarchitecture, provides complementary information to bone mineral density (BMD) in the assessment of osteoporotic fracture risk. This cross-sectional study aimed to determine whether TBS can identify patients with liver cirrhosis that are at risk of vertebral fractures. We enrolled 275 patients who completed evaluations for lumbar BMD, TBS, and vertebral fractures between November 2018 and April 2021. BMD was measured using dual-energy X-ray absorptiometry (DXA), TBS was calculated by analyzing DXA images using TBS iNsight software, and vertebral fractures were evaluated using Genant’s semi-quantitative method with lateral X-ray images. Factors associated with vertebral fractures and their correlation with the TBS were identified using regression models. Of the enrolled patients, 128 (47%) were female, the mean age was 72 years, and 62 (23%) were diagnosed with vertebral fractures. The prevalence of vertebral fractures was higher in women than in men (33% vs. 14%; p < 0.001). The unadjusted odds ratio (OR) of the vertebral fractures for one standard deviation decrease in TBS and BMD was 2.14 (95% confidence interval [CI], 1.69−2.73) and 1.55 (95% CI, 1.26−1.90), respectively. After adjusting for age, sex, and BMD, the adjusted OR of the vertebral fractures in TBS was 2.26 (95% CI, 1.52−3.35). Multivariate linear regression analysis showed that TBS was independently correlated with age (β = −0.211), body mass index (β = −0.251), and BMD (β = 0.583). TBS can help identify patients with cirrhosis at risk of vertebral fractures.

Similarities and differences between bone quality parameters, trabecular bone score and femur geometry

Bone quality is a critical factor that, along with bone quantity, determines bone strength. Image-based parameters are used for assessing bone quality non-invasively. The trabecular bone score (TBS) is used to assess quality of trabecular bone and femur geometry for cortical bone. Little is known about the associations between these two bone quality parameters and whether they show differences in the relationships with age and body mass index (BMI). We investigated the associations between the trabecular bone score (TBS) and femur cortical geometry. Areal bone mineral density (BMD) was assessed using dual energy X-ray absorptiometry (DXA) and the TBS was assessed using iNsight software and, femur geometry using APEX (Hologic). A total of 452 men and 517 women aged 50 years and older with no medical history of a condition affecting bone metabolism were included. Z-scores for TBS and cortical thickness were calculated using the age-specific mean and SD for each parameter. A ‘discrepancy group’ was defined as patients whose absolute Z-score difference between TBS and cortical thickness was > 1 point. TBS and cortical thickness correlated negatively with age both in men and women, but the associations were stronger in women. Regarding the associations with BMI, TBS provided significant negative correlation with BMI in the range of BMI > 25 kg/m². By contrast, cortical thickness correlated positively with BMI for all BMI ranges. These bone quality-related parameters, TBS and cortical thickness, significantly correlated, but discordance between these two parameters was observed in about one-third of the men and women (32.7% and 33.4%, respectively). Conclusively, image-based bone quality parameters for trabecular and cortical bone exhibit both similarities and differences in terms of their associations with age and BMI. These different profiles in TBS and FN cortical thickness might results in different risk profiles for the vertebral fractures or hip fractures in a certain percentage of people.

Level-Specific Volumetric BMD Threshold Values for the Prediction of Incident Vertebral Fractures Using Opportunistic QCT: A Case-Control Study

PURPOSE

To establish and evaluate the diagnostic accuracy of volumetric bone mineral density (vBMD) threshold values at different spinal levels, derived from opportunistic quantitative computed tomography (QCT), for the prediction of incident vertebral fractures (VF).

MATERIALS AND METHODS

In this case-control study, 35 incident VF cases (23 women, 12 men; mean age: 67 years) and 70 sex- and age-matched controls were included, based on routine multi detector CT (MDCT) scans of the thoracolumbar spine. Trabecular vBMD was measured from routine baseline CT scans of the thoracolumbar spine using an automated pipeline including vertebral segmentation, asynchronous calibration for HU-to-vBMD conversion, and correction of intravenous contrast medium (https://anduin.bonescreen.de). Threshold values at T1-L5 were calculated for the optimal operating point according to the Youden index and for fixed sensitivities (60 - 85%) in receiver operating characteristic (ROC) curves.

RESULTS

vBMD at each single level of the thoracolumbar spine was significantly associated with incident VFs (odds ratio per SD decrease [OR], 95% confidence interval [CI] at T1-T4: 3.28, 1.66-6.49; at T5-T8: 3.28, 1.72-6.26; at T9-T12: 3.37, 1.78-6.36; and at L1-L4: 3.98, 1.97-8.06), independent of adjustment for age, sex, and prevalent VF. AUC showed no significant difference between vertebral levels and was highest at the thoracolumbar junction (AUC = 0.75, 95%-CI = 0.63 - 0.85 for T11-L2). Optimal threshold values increased from lumbar (L1-L4: 52.0 mg/cm³) to upper thoracic spine (T1-T4: 69.3 mg/cm³). At T11-L2, T12-L3 and L1-L4, a threshold of 80.0 mg/cm³ showed sensitivities of 85 - 88%, and specificities of 41 - 49%. To achieve comparable sensitivity (85%) at more superior spinal levels, resulting thresholds were higher: 114.1 mg/cm³ (T1-T4), 92.0 mg/cm³ (T5-T8), 88.2 mg/cm³ (T9-T12).

CONCLUSIONS

At all levels of the thoracolumbar spine, lower vBMD was associated with incident VFs in an elderly, predominantly oncologic patient population. Automated opportunistic osteoporosis screening of vBMD along the entire thoracolumbar spine allows for risk assessment of imminent VFs. We propose level-specific vBMD threshold at the thoracolumbar spine to identify individuals at high fracture risk.

Lower trabecular bone score is associated with an increased incidence of localized femoral periosteal thickening

INTRODUCTION

Femoral localized periosteal thickening (LPT, also termed "beaking") of the lateral cortex often precedes an atypical femoral fracture (AFF). Bisphosphonate (BP) use, glucocorticoid use, and Asian race are major risk factors for developing such fractures. The aim of this study was to determine whether the trabecular bone score (TBS) reflecting the lumbar trabecular microarchitecture was related to LPT in glucocorticoid-treated Japanese patients with autoimmune diseases.

MATERIALS AND METHODS

We retrospectively investigated 111 women with autoimmune diseases treated with prednisolone (PSL) who had undergone both femoral X-ray and dual-energy X-ray absorptiometry of the L1 - L4 lumbar vertebrae and for whom TBS could be evaluated for two or more of these.

RESULTS

Femoral LPT was evident in the X-rays of 18 of 111 patients (16.2%). Higher body mass index (BMI), longer duration of PSL use and longer duration of BP use were significant in patients with LPT compared to those without. The TBS was significantly lower in patients with LPT than in those without (1.314 ± 0.092 vs. 1.365 ± 0.100, p = 0.044); however, the lumbar bone mineral density did not differ significantly (0.892 ± 0.141 vs. 0.897 ± 0.154 g/cm², p = 0.897). TBS was significantly associated with LPT (odds ratio, 0.004; 95% CI, 0 - 0.96; p = 0.048), but not in the multivariate analysis including BMI, duration of PSL use and duration of BP use.

CONCLUSIONS

The TBS was lower in glucocorticoid-treated Japanese women with autoimmune diseases with LPT than in those without LPT, and deteriorated trabecular microarchitecture influenced by longer use of BP and glucocorticoid might be associated with the development of LPT.

Age-Specific Normative Values of Lumbar Spine Trabecular Bone Score (TBS) in Taiwanese Men and Women

Trabecular bone score (TBS) is a novel method for assessing trabecular microarchitecture. Normative values of TBS are available for various populations of the world but are not yet available for Taiwanese adults. Therefore, the purpose of this study was to estimate age-specific, normative TBS curves for Taiwanese men and women. Medical records of general health examinations from a regional hospital in Southern Taiwan were reviewed. Individuals aged 30–90 years with data on lumbar spine bone mineral density (BMD) were included. TBS was retrospectively calculated from dual-energy X-ray absorptiometry scans using TBS iNsight software. Of the 12,028 patients included, 4533 (37.7%) were male and the mean age was 55.8 years. The mean TBS was 1.392 (standard deviation (SD) 0.089) for men and 1.344 (SD 0.107) for women. In women, TBS declined at a rate of 0.0004/year among those aged 30.0–45.9 years, 0.0106/year among those 46.0–60.7 years, and 0.0028/year among those 60.8–90.0 years. In men, TBS declined at a constant rate of 0.0023/year over the entire age range. In conclusion, age-adjusted, normative curves of TBS for Taiwanese men and women are presented, which could be used to facilitate the use of TBS in assessing bone status in clinical practice.

Trabecular bone score in women with differentiated thyroid cancer on long-term TSH-suppressive therapy

INTRODUCTION

Thyrotropin stimulating hormone (TSH) suppression in patients with differentiated thyroid cancer (DTC) aims to decrease the growth and proliferation of thyroid cancer cells. However, the effect of TSH-suppressive therapy on bone microarchitecture remains undefined.

METHODS

Cross-sectional study including 43 women with DTC undergoing TSH-suppressive therapy (sTSH) compared to 20 women also on levothyroxine (LT4) therapy but with TSH in the low-normal range (nTSH) since the thyroid surgery. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA), and trabecular bone score (TBS) was evaluated using the TBS iNsigth software. Fracture risk assessed by FRAX, with and without TBS, was calculated. The relationship between suppressive therapy-related parameters and bone parameters was investigated.

RESULTS

The TBS mean values were not significantly different in the sTSH and nTSH groups (1.273 ± 0.12 vs 1.307 ± 0.14, p = 0.7197). In both groups, postmenopausal women had degraded microarchitecture (TBS 1.216 ± 0.11 vs 1.213 ± 0.09, p = 0.9333), while premenopausal women had normal microarchitecture (1.328 ± 0.11 vs 1.401 ± 0.12, p = 0.195). The percentage of all postmenopausal women with degraded TBS was 54.7%, while the percentage of osteoporosis diagnoses was 16.1%. The TBS-adjusted FRAX-probability of fracture was similar in sTSH and nTSH groups. Body mass index (BMI) and menopausal status were the only variables associated with TBS and BMD.

CONCLUSION

Trabecular microarchitecture assessed by TBS was similar between women on long-term suppressive therapy in DTC and those on LT4 replacement therapy aiming at a TSH level within the low-normal reference range. Low TBS values were observed in postmenopausal women of both groups, suggesting that not only suppressed TSH levels but also a low-normal TSH is associated with deteriorated bone microarchitecture in postmenopausal women following total thyroidectomy.

Trabecular Bone Score Could Not Predict the Bone Mineral Density of Proximal Humerus

Background

Osteoporosis is an important clinical factor for tendon healing after arthroscopic rotator cuff repair (ARCR). Conventional dual energy X-ray absorptiometry (DXA) of the hip and lumbar spine (LS) does not represent proximal humeral bone mineral density (BMD). Theoretically, direct measurement of the BMD of the proximal humerus is the best method; however, it is not popular and is non-standardized. Therefore, we evaluate whether the trabecular bone score (TBS) using LS DXA would represent proximal humeral BMD.

Methods

Conventional hip and LS DXA and proximal humeral BMD were measured in 212 consecutive ARCR patients, and TBS was calculated using LS DXA. Comparative analysis between the affected and contralateral asymptomatic shoulders was done; moreover, correlation analysis was conducted to evaluate the representativity of TBS for proximal humeral BMD. Regression analysis was performed to elucidate the risk factor of intraoperative suture anchor failure (ISAF).

Results

BMDs of the affected shoulder were significantly lower than those of the contralateral side (all P<0.05). TBS failed to present a strong correlation with proximal humeral BMD (correlation coefficients 0.155–0.506, all P<0.05), and the BMD of the greater tuberosity (GT) of the proximal humerus was revealed to be a sole risk factor for ISAF (odds ratio, 0.01, P=0.020).

Conclusions

TBS and conventional hip and LS DXA did not represent proximal humeral BMD. Furthermore, among the various radiological measurements, the BMD of the GT was a sole risk factor of ISAF. Therefore, further research for the direct measurement of proximal humeral BMD is mandatory to predict proximal humeral focal osteoporosis.

Application of the Trabecular Bone Score in Clinical Practice

The trabecular bone score (TBS) was introduced as an indirect index of trabecular microarchitecture, complementary to bone mineral density (BMD), and is derived using the same dual energy X-ray absorptiometry images. Recently, it has been approved for clinical use in Korea. Therefore, we conducted a comprehensive review to optimize the use of TBS in clinical practice. The TBS is an independent predictor of osteoporotic fractures in postmenopausal women and men aged >50 years. The TBS is potentially useful in monitoring the skeletal effects of anabolic agents but not of antiresorptive agents. In postmenopausal women with type 2 diabetes mellitus, the TBS assesses osteoporotic fracture risk not captured by BMD. However, high body mass index and soft tissue thickness can cause underestimation of the TBS; however, this limitation has been improved in recent versions of the TBS software. However, a high precision error and low reproducibility limit the use of TBS. This review may provide information on the application of the TBS in clinical practice based on reliable evidence.

Role of deteriorated bone quality in the development of osteoporosis in pheochromocytoma and paraganglioma

CONTEXT

Pheochromocytoma (PHEO) and paraganglioma (PGL) (PHEO and PGL: PPGLs), catecholamine-producing tumors, represent an emerging cause of secondary osteoporosis. However, despite decreased bone mineral density (BMD), vertebral fracture (VF) is not associated with BMD in PPGLs.

OBJECTIVE

To evaluate whether deteriorated bone quality is involved in the development of osteoporosis in PPGLs.

PARTICIPANTS

Trabecular bone score (TBS), used to assess trabecular bone quality, was examined in 56 patients with PPGLs and 52 with non-functional adrenal tumors (AT). Radiograph of the spine was carried out in 35 patients with PPGLs, and TBS was analyzed in 18 patients with PPGLs at follow-up.

MAIN OUTCOME MEASURE

TBS and BMD at the lumbar spine in patients with PPGLs with and without VF.

RESULTS

PPGLs had a lower TBS (n = 56, 1.338 [1.294-1.420]) than non-functional AT (n = 52, 1.394 [1.342-1.444]; p = 0.033). Among those with PPGLs, patients with VF (n = 14, 1.314 [1.289-1.346]) had a lower TBS than those without VF (n = 21, 1.383 [1.324-1.426]; p = 0.046), despite no significant difference in BMD at the lumbar spine between the two groups (p = 0.501). An optimal cut-off level of TBS for diagnosing VF in PPGLs was 1.323, and its area under the curve was 0.702. The severity of catecholamine excess and maximal size of tumor were associated with decreased TBS in PPGLs patients (p = 0.016 and p = 0.020, respectively). Surgical resection of PPGLs improved TBS at follow-up, with 2.5% increase (p = 0.007).

CONCLUSIONS

This study provides evidence for the importance of deteriorated bone quality rather than decreased bone mass in the development of VF in PPGLs.

Premenopausal and early postmenopausal trabecular bone score (TBS) and fracture risk: Study of Women's Health Across the Nation (SWAN)

BACKGROUND

Evidence that trabecular bone score (TBS), an index of bone microstructure, is a risk factor for future fracture comes mainly from studies of late postmenopausal women.

OBJECTIVE

To discern whether premenopausal TBS or early postmenopausal TBS predict fracture.

DESIGN

A 22-year, prospective analysis from the Study of Women's Health Across Nation.

SETTING

Community-based cohort.

PARTICIPANTS

272 Black, 174 Japanese, and 364 White women.

MAIN OUTCOME MEASURES

Incident fractures: 292 in premenopausal sample and 141 in early postmenopausal sample.

RESULTS

Separate Cox proportional hazard regressions modeled time to incident fracture as a function of TBS measured during premenopause or early postmenopause. Models were initially adjusted for age, race/ethnicity, SWAN clinical site, body mass index, use of calcium, vitamin D, bone beneficial or bone adverse medication. Next, we added lumbar spine (LS) or femoral neck (FN) bone mineral density (BMD) and, finally, history of prior fracture, to the models. For each standard deviation decrement in premenopausal TBS, fracture hazard was elevated by 17% (relative hazard [RH] 1.17 [95% CI, 1.02-1.35]); after adjusting for LS or FN BMD, the relation between premenopausal TBS and fracture was no longer statistically significant. There was a similar-magnitude, marginally statistically significant, association between early postmenopausal TBS and fracture, unadjusted for BMD (RH 1.15 [0.95-1.39]).

CONCLUSIONS

Variation in premenopausal TBS is related to fracture risk, but this association is not independent of BMD.

Ability of FRAX Sri Lanka adjusted for trabecular bone score to discriminate between postmenopausal women with a recent fracture and without a fracture

Objectives

We evaluated the ability of fracture risk assessment tool (FRAX) Sri Lanka to discriminate between women with a recent fracture and without a fracture, when trabecular bone score (TBS) is added to the calculation.

Methods

We studied 394 women without previous fractures and 87 women who underwent dual energy X-ray absorptiometry within 3 months after the first fragility fracture. Fracture probabilities (FP) were estimated with and without TBS using Sri Lankan FRAX model and their ability to discriminate those with and without fracture was tested.

Results

Women without fractures had higher bone mineral densities (BMDs) and lower FPs, compared to those with a recent fracture. Area under curves of receiver operating characteristic for FPs unadjusted were not different from those adjusted for TBS. The odd ratios of FPs unadjusted were not different from those of adjusted. The FPs estimated with TBS were higher, hence the intervention thresholds (ITs) were higher compared to FPs estimated without TBS. Thirty-two percent of women without previous fracture were above the ITs and the inclusion of TBS increased this to 36%. The integrated discriminatory index analysis showed a 8% increase in the discriminatory slope.

Conclusions

The inclusion of TBS to Sri Lankan FRAX did not show an added advantage in discriminating between postmenopausal women with a recent fracture and without a fracture. TBS inclusion in fracture risk calculation among those without previous fractures, however, showed a marginal increase in the number of women above ITs.

Effects of metabolic syndrome on bone health in older adults: the Bushehr Elderly Health (BEH) program

Based on the clinical, BMD, and TBS data of 2380 participants aged ≥ 60 which was gathered during the BEH program, stage II, we showed that MetS was positively associated with BMD, while a negative or no association was observed between MetS and TBS depending on the sex and the adjustment model.

INTRODUCTION

The results of previous reports in regard to the effect of metabolic syndrome (MetS) on bone health are not conclusive. This study aimed to evaluate the association between MetS with bone mineral density (BMD) and trabecular bone score (TBS) as an indicator of bone quantity and quality, respectively.

METHODS

Using a cross-sectional design, this study was carried out based on the data collected during the BEH Program, stage II. MetS was defined according to NCEP-ATP III criteria. BMD (at the lumbar spine and the hip) and lumbar spine TBS were assessed by dual-energy X-ray absorptiometry device.

RESULTS

The data of 2380 participants (women = 1228, men = 1152) aged ≥ 60 were analyzed. In the fully adjusted regression models (including BMI), significant associations between MetS and mean BMD were observed across all locations in men (P values ≤ 0.001) and in the lumbar spine in women (P value = 0.003). In addition, the prevalence of osteoporosis (based on BMD) was significantly lower in those with MetS than those without MetS in both sexes, even after full adjustments (women, OR = 0.707, P value = 0.013; men, OR = 0.563, P value = 0.001). In contrast, in age-adjusted regression analyses, the prevalence of degraded bone microarchitecture (TBS ≤ 1.2) was significantly increased in those with MetS than those without, irrespective of the participants' sex (P values < 0.05). The mean TBS was also negatively associated with MetS in women (β = - 0.075, P value = 0.007) but not in men (β = - 0.052, P value = 0.077), in age-adjusted regression models. However, after including BMI in the adjusted models, all significant associations between TBS values and MetS disappeared.

CONCLUSION

It seems that a positive association exists between MetS and BMD, while MetS is either not associated or negatively correlated with bone quality as measured by TBS.

Relationship between Skeletal Muscle Mass, Bone Mineral Density, and Trabecular Bone Score in Osteoporotic Vertebral Compression Fractures

STUDY DESIGN

A retrospective observational study was performed.

PURPOSE

We investigated the relationships between skeletal muscle mass, bone mineral density (BMD), and trabecular bone score (TBS) in patients with osteoporotic vertebral compression fractures (VCFs).

OVERVIEW OF LITERATURE

The TBS has attracted attention as a measurement of trabecular bone microarchitecture. It is derived from data obtained using dual-energy X-ray absorptiometry (DXA) and is a reported indicator of VCFs, and its addition to the Fracture Risk Assessment Tool increases the accuracy of fracture prediction.

METHODS

BMD, skeletal muscle mass, and TBS were measured in 142 patients who visited Shimoshizu National Hospital from April to August 2019. Patients were divided into a VCF group and a non-VCF group. Whole-body DXA scans were performed to analyze body composition, including appendicular skeletal muscle mass index (SMI; lean mass [kg]/height [m2]) and BMD. The diagnostic criteria for sarcopenia was an appendicular SMI <5.46 kg/m2. A logistic regression analysis was conducted to identify the risk factors for VCFs.

RESULTS

The significant (p<0.05) findings (VCF group vs. non-VCF group, respectively) included age (79 vs. 70 years), femoral BMD (0.50 vs. 0.58 g/cm2), TBS (1.25 vs. 1.29), and lower limb muscle mass (8.6 vs. 9.9 kg). The VCF group was significantly older and had a lower femur BMD and decreased leg muscle mass than the non-VCF group. Based on the multiple logistic regression analysis, lower femoral BMD and decreased leg muscle mass were identified as risk factors for vertebral fracture independent of age, but the TBS was not.

CONCLUSIONS

Patients with VCFs had low BMD, a low TBS, and low skeletal muscle mass. Lower femoral BMD and decreased leg muscle mass were identified as risk factors for VCFs independent of age, whereas the TBS was not identified as a risk factor for VCFs.

Bone Microarchitecture Assessed by Trabecular Bone Score Is Independent of Mobility Level or Height in Pediatric Patients with Cerebral Palsy

Bone strength and fracture risk do not only depend on bone density, but also on bone structure. The trabecular bone score (TBS) evaluates homogeneity of bone microarchitecture indirectly by measuring gray-level variations of two-dimensional (2D) DXA images. Although TBS is well-established for adults, there have been only few publications in pediatrics. In this monocentric retrospective analysis, we investigated TBS in children and adolescents with cerebral palsy (CP), a patient group vulnerable to low bone mineral mass due to impaired mobility. The influence of different parameters on TBS and areal BMD (aBMD) were evaluated, as well as the relationship between TBS and aBMD. We compared TBS values of our study population to a reference population. A total of 472 lumbar spine-dual-energy X-ray absorptiometry (LS-DXA) scans of children and adolescents with CP (205 female), aged between 4 and 18 years, were analyzed. The DXA-scans were part of the routine examination. The children had no records of fractures or specific bone diseases. Our study population with CP had similar TBS as the reference population. TBS did not increase with age until an inflection point at 10 years in females, and 12 years in males. Girls had significantly higher TBS than boys (p = .049) and pubertal girls aged 8 to 13 years had significantly higher TBS than prepubertal girls (p = .009). TBS standard deviation score for age (SDS-TBS) and aBMD Z-scores correlated weakly (p < .001; R = 0.276 [males], R = 0.284 [females]). Other than for aBMD Z-scores, SDS-TBS was not influenced by age-adjusted height Z-scores and there was no significant difference in SDS-TBS when grouped by mobility levels, using the Gross Motor Function Classification System (GMFCS). Our results indicate that children with CP have a similar homogeneous distribution of trabecular microarchitecture as controls. Puberty initiation appears to be essential for increase of TBS with age and for sex differences. TBS seems less influenced by body composition, height, and mobility than aBMD. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Combining Frailty and Trabecular Bone Score Did Not Improve Predictive Accuracy in Risk of Major Osteoporotic Fractures

It is recognized that the trabecular bone score (TBS) provides skeletal information, and frailty measurement is significantly associated with increased risks of adverse health outcomes. Given the suboptimal predictive power in fracture risk assessment tools, we aimed to evaluate the combination of frailty and TBS regarding predictive accuracy for risk of major osteoporotic fracture (MOF). Data from the prospective longitudinal study of CaMos (Canadian Multicentre Osteoporosis Study) were used for this study. TBS values were estimated using lumbar spine (L₁ to L₄ ) dual-energy X-ray absorptiometry (DXA) images; frailty was evaluated by a frailty index (FI) of deficit accumulation. Outcome was time to first incident MOF during the follow-up. We used the Harrell's C-index to compare the model predictive accuracy. The Akaike information criterion, likelihood ratio test, and net reclassification improvement (NRI) were used to compare model performances between the model combining frailty and TBS (subsequently called "FI + TBS"), FI-alone, and TBS-alone models. We included 2730 participants (mean age 69 years; 70% women) for analyses (mean follow-up 7.5 years). There were 243 (8.90%) MOFs observed during follow-up. Participants with MOF had significantly higher FI (0.24 versus 0.20) and lower TBS (1.231 versus 1.285) than those without MOF. FI and TBS were significantly related with MOF risk in the model adjusted for FRAX with bone mineral density (BMD) and other covariates: hazard ratio (HR) = 1.26 (95% confidence interval [CI] 1.11-1.43) for per-SD increase in FI; HR = 1.38 (95% CI 1.21-1.59) for per-SD decrease in TBS; and these associations showed negligible attenuation (HR = 1.24 for per-SD increase in FI, and 1.35 for per-SD decrease in TBS) when combined in the same model. Although the model FI + TBS was a better fit to the data than FI-alone and TBS-alone, only minimal and nonsignificant enhancement of discrimination and NRI were observed in FI + TBS. To conclude, frailty and TBS are significantly and independently related to MOF risk. Larger studies are warranted to determine whether combining frailty and TBS can yield improved predictive accuracy for MOF risk. © 2020 American Society for Bone and Mineral Research.

Trabecular Bone Score-An Emerging Tool in the Management of Osteoporosis

Areal bone mineral density (aBMD) is currently the gold standard for the diagnosis of osteoporosis, however, it has its own pitfalls. Trabecular bone score (TBS), a novel tool in the evaluation of osteoporosis is an indirect indicator of bone microarchitecture. It is a textural index that evaluates pixel gray-level variations in the lumbar spine DXA (dual energy X-ray absorptiometry) image. Both cross-sectional and longitudinal studies have demonstrated that TBS may independently predict fragility fractures. TBS can also be used to adjust FRAX probabilities of fracture, though data available till date doesn't support any additional benefit. TBS also shows an improving trend with anti-osteoporotic treatment; however, the least significant change (LSC) is high that it takes more than 2 years for the change to manifest. TBS is also used in the evaluation of bone strength in cases of secondary osteoporosis. Though TBS predicts fracture risk independently in both genders, with the currently available data, it cannot be recommended as a standalone tool for decision regarding treatment of osteoporosis. TBS can be used as a tool to complement BMD in assessment of bone health. Additional studies are needed to assess its utility in clinical practice.

Bone material strength index is associated with prior fracture in men with and without moderate chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk for fracture. The ability of bone mineral density (BMD) to predict fractures in CKD patients has been inconsistent. Other measures such as trabecular bone score (TBS) and impact microindentation (IMI) may be more useful in this group. This study aimed to determine if TBS or IMI values differed between men with and without CKD and examine associations between prior fracture, TBS and IMI values.

METHODS

Men (n = 343, age 33-96 yr) from the Geelong Osteoporosis Study were included. Femoral neck (FNBMD) and lumbar spine BMD (LSBMD) were measured using DXA (Lunar ProdigyPro). TBS was determined from lumbar spine scans (TBS iNsight software Version 2.2). IMI values (bone material strength index; BMSi) were measured using an OsteoProbe. CKD was defined as an eGFR<60 mL/min/1.73m² (n = 53). Prior low trauma fractures (n = 37) were ascertained from radiological reports. Associations were examined using binary logistic regression, adjusting for potential confounders. Interaction terms were tested in all models.

RESULTS

Men with CKD tended to have a higher likelihood of prior fracture (adjusted OR 2.27, 95%CI 1.02-5.01). Higher BMSi was associated with a lower likelihood of prior fracture (adjusted OR for 1SD increase: 0.70; 95%CI 0.51-0.97). This association was sustained after adjustment for FNBMD (OR 0.68; 95%CI 0.49-0.96) or LSBMD (OR 0.69; 95%CI 0.49-0.95). No interaction was detected between BMSi and CKD (p = 0.898). No associations were detected between FNBMD, LSBMD or TBS and prior fracture in either population and there were no interactions with CKD for FNBMD, LSBMD or TBS.

CONCLUSIONS

BMSi was associated with prior fracture in men with and without CKD, however, FNBMD, LSBMD and TBS were not. Lack of an interaction term suggests that BMSi performed similarly in identifying the likelihood of prior fracture, regardless of CKD status. IMI may have clinical utility for assessing fracture risk in patients with CKD.

Quantitative computed tomography discriminates between postmenopausal women with low spine bone mineral density with vertebral fractures and those with low spine bone mineral density only: the SHATTER study

Lumbar spine volumetric bone mineral density (BMD) measured using quantitative computed tomography (QCT) can discriminate between postmenopausal women with low areal BMD with and without vertebral fractures. QCT provides a 3D measure of BMD, excludes the vertebral posterior elements and accounts for bone size. This knowledge could contribute to effective treatment targeting of patients with low BMD.

INTRODUCTION

We evaluated the ability of lumbar spine bone mineral apparent density (BMAD), trabecular bone score (TBS) and volumetric bone mineral density (vBMD) to discriminate between postmenopausal women with low areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) with and without vertebral fractures. The discriminatory ability of lumbar spine aBMD was compared with that of BMAD, TBS and vBMD.

METHODS

We studied three groups of postmenopausal women, i.e. group 1, aBMD T-score < - 1.0 and ≥ 1 vertebral fracture (n = 39); group 2, aBMD T-score < - 1.0 and no vertebral fracture, age- and aBMD-matched to group 1 (n = 34); group 3, aBMD score > - 1 and no vertebral fracture, age-matched to group 1 (n = 37). Lumbar spine aBMD was measured by DXA. BMAD was calculated using the DXA scan results. TBS was derived following DXA scan image reanalysis. Lumbar spine vBMD was assessed by quantitative computed tomography and Mindways Pro software. Differences in variables between groups 1, 2 and 3 were examined using general linear univariate modelling approaches. Area under the receiver operating characteristic (ROC) curve was calculated for BMAD, TBS and vBMD to determine the ability of lumbar spine measurement variables to discriminate between group 1 and group 2. A comparison of ROCs was performed.

RESULTS

Lumbar spine BMAD and TBS measurement variables were similar for groups 1 and 2. However, vBMD was significantly lower in group 1 and could discriminate between those women with low aBMD with (group 1) and without vertebral fractures (group 2).

CONCLUSIONS

We conclude that lumbar spine vBMD may discriminate well between postmenopausal women with low aBMD with and without vertebral fractures as it provides a 3D measure of bone mineral density, excludes the posterior elements of the vertebrae and takes into account bone size. A unique feature of the SHATTER study is that groups 1 and 2 were matched for aBMD, thus our study findings are independent of aBMD. Furthermore, we observed that neither BMAD nor TBS could distinguish between women with low aBMD with and without vertebral fractures. The knowledge gained from the SHATTER study will influence clinical and therapeutic decision-making, thereby optimising the care of patients with and without vertebral and other fragility fractures.

[Evaluation of the trabecular bone score (TBS) in routine clinical care of patients with inflammatory rheumatic and non-inflammatory diseases : Correlation with conventional bone mineral density measurement and prevalence of vertebral fractures]

Hintergrund

Osteoporosebedingte Frakturen sind bei Patienten mit rheumatoider Arthritis (RA) häufig. Die Messung der Knochenmineraldichte (KDM) mit der Dual-Energie-Röntgenabsorptionsmessung (DXA) allein sagt das Frakturrisiko nur begrenzt voraus. Der Trabecular Bone Score (TBS) ist ein Surrogatmarker für die trabekuläre Mikroarchitektur des Knochens, der das Frakturrisiko unabhängig von der KDM vorhersagen kann.

Ziel

Ermittlung der Prävalenz von KDM, TBS und osteoporotisch bedingten Wirbelkörperbrüchen („vertebral fractures“ [VF]) bei Patienten mit RA im Vergleich zu Kontrollen mit nichtentzündlichen Muskel-Skelett-Erkrankungen (MSK).

Methoden

Die Daten von Patienten mit von Rheumatologen diagnostizierter RA und verfügbaren TBS- und DXA-Messungen, die in unserem Krankenhaus von 2006 bis 2014 erhoben wurden, wurden retrospektiv analysiert. Den RA-Patienten wurden Kontrollen mit nichtentzündlichen MSK zugeordnet. Eine „reduzierte Knochengesundheit“ wurde definiert als ein T‑Score <−1,0 und/oder ein TBS-Wert <−1,31. Statistische Vergleiche wurden mit dem Mann-Whitney- und dem Wilcoxon-Test durchgeführt.

Ergebnisse

Es wurden 143 Patienten mit RA (Alter 72,1 ± 11,1 Jahre, 72 % weiblich) und 106 Kontrollen (Alter 69,6 ± 12,6 Jahre, 75 % weiblich) eingeschlossen. RA-Patienten hatten häufiger eine erniedrigte KDM (n = 102; 71,3 %) und einen erniedrigen TBS-Wert (n = 125; 87,4 %) als die Kontrollen (n = 63; 59,4 % und n = 79; 74,5 %, p = 0,049 und p = 0,009). RA-Patienten hatten mehr VF (n = 52, 36,4 %) als Kontrollen (n = 24, 22,6 %, p = 0,02). Insgesamt hatten 20 Patienten mit VF (26,3 %) eine normale Wirbelsäulen-KDM und 9 (11,8 %) auch eine normale Hüft-KDM. Bei Patienten mit VF war die Kombination eines niedrigen TBS bei normaler WS-KDM häufiger als ein normaler TBS bei niedriger WS-KDM (p = 0,008 für RA, p = 0,025 für Kontrollen).

Diskussion

VF treten bei Patienten mit normaler KDM auf. Bei Patienten mit VF wurde eine niedrige TBS bei normaler Wirbelsäulen-KDM häufiger gefunden als eine normale TBS bei niedriger Wirbelsäulen-KDM. Die Messung des TBS scheint für die Erkennung eines erhöhten Frakturrisikos bei RA-Patienten mit normaler WS-KDM nützlich zu sein.

Determinants of trabecular bone score and prevalent vertebral fractures in women with fragility fractures: a cross-sectional sub-study of NoFRACT

Determinants of trabecular bone score (TBS) and vertebral fractures assessed semiquantitatively (SQ1-SQ3) were studied in 496 women with fragility fractures. TBS was associated with age, parental hip fracture, alcohol intake and BMD, not SQ1-SQ3 fractures. SQ1-SQ3 fractures were associated with age, prior fractures, and lumbar spine BMD, but not TBS.

INTRODUCTION

Trabecular bone score (TBS) and vertebral fractures assessed by semiquantitative method (SQ1-SQ3) seem to reflect different aspects of bone strength. We therefore sought to explore the determinants of and the associations between TBS and SQ1-SQ3 fractures.

METHODS

This cross-sectional sub-study of the Norwegian Capture the Fracture Initiative included 496 women aged ≥ 50 years with fragility fractures. All responded to a questionnaire about risk factors for fracture, had bone mineral density (BMD) of femoral neck and/or lumbar spine assessed, TBS calculated, and 423 had SQ1-SQ3 fracture assessed.

RESULTS

Mean (SD) age was 65.6 years (8.6), mean TBS 1.27 (0.10), and 33.3% exhibited SQ1-SQ3 fractures. In multiple variable analysis, higher age (β_{per SD} = - 0.26, 95% CI: - 0.36,- 0.15), parental hip fracture (β = - 0.29, 95% CI: - 0.54,- 0.05), and daily alcohol intake (β = - 0.43, 95% CI - 0.79, - 0.08) were associated with lower TBS. Higher BMD of femoral neck (β_{per SD} = 0.34, 95% CI 0.25-0.43) and lumbar spine (β_{per SD} = 0.40, 95% CI 0.31-0.48) were associated with higher TBS. In multivariable logistic regression analyses, age (OR_{per SD} = 1.94, 95% CI 1.51-2.46) and prior fragility fractures (OR = 1.71, 95% CI 1.09-2.71) were positively associated with SQ1-SQ3 fractures, while lumbar spine BMD (OR_{per SD} = 0.75 95% CI 0.60-0.95) was negatively associated with SQ1-SQ3 fractures. No association between TBS and SQ1-SQ3 fractures was found.

CONCLUSION

Since TBS and SQ1-SQ3 fractures were not associated, they may act as independent risk factors, justifying the use of both in post-fracture risk assessment.

X-ray-based quantitative osteoporosis imaging at the spine

Osteoporosis is a metabolic bone disease with a high prevalence that affects the population worldwide, particularly the elderly. It is often due to fractures associated with bone fragility that the diagnosis of osteoporosis becomes clinically evident. However, early diagnosis would be necessary to initiate therapy and to prevent occurrence of further fractures, thus reducing morbidity and mortality. X-ray-based imaging plays a key role for fracture risk assessment and monitoring of osteoporosis. Whereas over decades dual-energy X-ray absorptiometry (DXA) has been the main method used and still reflects the reference standard, another modality reemerges with quantitative computed tomography (QCT) because of its three-dimensional advantages and the opportunistic exploitation of routine CT scans. Against this background, this article intends to review and evaluate recent advances in the field of X-ray-based quantitative imaging of osteoporosis at the spine. First, standard DXA with the recent addition of trabecular bone score (TBS) is presented. Secondly, standard QCT, dual-energy BMD quantification, and opportunistic BMD screening in non-dedicated CT exams are discussed. Lastly, finite element analysis and microstructural parameter analysis are reviewed.

Association between Trunk Muscle Strength, Lumbar Spine Bone Mineral Density, Lumbar Scoliosis Angle, and Skeletal Muscle Volume and Locomotive Syndrome in Elderly Individuals: A Dual-Energy X-ray Absorptiometry Study

Introduction

The present study aimed to investigate the association between trunk muscle strength, lumbar spine bone mineral density (BMD), lumbar scoliosis angle (LSA), and appendicular skeletal muscle mass index (ASMI) and the severity locomotive syndrome (LS) using dual-energy X-ray absorptiometry (DXA) technology in elderly individuals.

Methods

In this cross-sectional study, we enrolled 168 individuals aged >60 years. We measured their trunk muscle strength (flexion and extension) and BMD, LSA, and ASMI using DXA. We defined degenerative lumbar scoliosis (DLS) as LSA ≥ 10° by the Cobb method using the DXA image. The locomotor function was evaluated using the timed up-and-go (TUG) test and the 25-question Geriatric Locomotive Function Scale (GLFS-25) score. Normal locomotor function, LS-1, and LS-2 were defined as a GLFS-25 score of <7, ≥7 and <16, and ≥16, respectively. We compared the three groups, analyzing the associations between all variables and the locomotor function using univariate and multivariate analyses.

Results

Although there was no significant difference in sex ratio, BMD, ASMI, and trunk-flexor strength, significant differences were observed in age (p < 0.01), the prevalence of DLS (p = 0.02), trunk-extensor strength (p < 0.01), and trunk-extensor/flexor strength ratio (p < 0.01) among the three groups. In multiple regression analyses, the significant risk factors of the TUG test were age (β = 0.26), body mass index (β = 0.36), LSA (β = 0.15), ASMI (β = -0.30), and trunk-extensor strength (β = -0.19), whereas the significant factor of the GLFS-25 score was trunk-extensor strength (β = -0.31).

Conclusions

The results indicate that it is clinically important for LS to pay careful attention not only to BMD but also to lumbar scoliosis when DXA examination of the lumbar spine is routinely conducted. Moreover, it is essential to note that trunk-extensor strength is more important than trunk-flexor strength in maintaining locomotor function in elderly individuals.

Risk factors for vertebral fracture in primary hyperparathyroidism

PURPOSE

Screening for vertebral fractures (VF) in primary hyperparathyroidism (PHPT) is recommended, but there are limited data regarding which patients are at greatest risk for VF. We evaluated risk factors for VF in PHPT.

METHODS

This is a retrospective cross-sectional analysis of 117 participants with PHPT. We assessed Grades 2 and 3 VF by vertebral fracture assessment (VFA) and the association of VF with the trabecular bone score (TBS), other skeletal parameters and clinical risk factors. VFA was performed only in those who met National Osteoporosis Foundation criteria for VFA screening.

RESULTS

T-scores were in the osteopenic range and TBS was degraded. Overall VF rate based on VFA or other imaging was 12.8%. Serum PTH, calcium and TBS were not associated with VF. Those with VF were older (p = 0.04), had worse renal function (p = 0.04), were more likely to have received osteoporosis treatment (p = 0.03), and tended to have had a prior fracture (p = 0.06). T-scores did not differ by fracture status at any skeletal site. Those with VF had nine times the odds of osteoporosis at the hip (95% CI 2.4-34.5), but this risk factor had low sensitivity (46.7%) for VF. Hip T-score < -2.6, Age > 78.6 years, and GFR < 58.8 ml/min/1.73 m² (thresholds maximizing sensitivity and specificity) had areas under the curve of 0.60-0.67 for VF (all p < 0.05) and low sensitivity. Findings were similar when analyses were limited to women.

CONCLUSIONS

In PHPT, VF risk factors included older age, prior fracture, worse renal function and osteoporosis at the hip, but not osteoporosis at other sites, TBS or biochemical indices of PHPT. Since identified risk factors had low sensitivity and were generally inaccurate for categorizing those with VF, the data do not support limiting screening to PHPT patients with these specific VF risk factors.

Decreased bone mineral density and osteoporotic fractures are associated with the development of echogenic plaques in the carotid arteries over a 10-year follow-up period: The Japanese Population-based Osteoporosis (JPOS) Cohort Study

OBJECTIVES

To investigate whether low bone mineral density (BMD) and history of fracture at baseline are associated with the development of echogenic carotid plaques over a 10-year follow-up period.

STUDY DESIGN

A prospective cohort study.

MAIN OUTCOME MEASURES

Development of echogenic plaques identified by ultrasonography of the carotid arteries.

METHODS

Among 1048 women aged 40 or more who completed the baseline survey of the Japanese Population-based Osteoporosis (JPOS) cohort study, 500 women who completed the first decade of follow-up and 267 women who completed the second decade of follow-up were included. We identified history and incidence of clinical osteoporotic fracture during the follow-up through medical interviews, and determined vertebral fractures by morphometry of absorptiometric images.

RESULTS

We identified 67 (13.4%) and 31 (11.6%) women with echogenic plaques at the end of first and second decade of follow-up, respectively. Participants with echogenic plaques were significantly older, exhibited lower spine BMD, and had a higher prevalence of osteoporotic fracture, diabetes, and hypertension. A generalized estimating equation analysis was used to combine the participants from the two follow-up periods into a single cohort, and showed that osteoporotic BMD and osteoporotic fractures were significantly associated with the development of echogenic plaques, after adjusting for atherosclerosis risk factors (odds ratio (OR): 2.15, 95% confidence interval (95% CI): 1.04, 4.44; OR: 1.84, 95% CI: 1.03, 3.28, respectively).

CONCLUSION

Osteoporotic BMD and osteoporotic fracture history were significantly, and independently, associated with an increased occurrence of echogenic plaques. Ultrasonographic screening of the carotid artery may benefit patients with osteoporosis.

Trabecular bone score: a useful clinical tool for the evaluation of skeletal health in women of short stature

PURPOSE

Areal bone mineral density (aBMD) by DXA is underestimated in those with smaller bones and overestimated in those with larger bones. Trabecular bone score (TBS) predicts fracture risk, and is not influenced by bone size. The aim of this study was to evaluate TBS and BMD in women with short stature.

METHODS

We retrospectively analyzed DXA scans of all women aged 50-90 years with short stature (<144 cm) obtained in a single center, from 2006 to 2016. The comparison group comprised women >161 cm in height, matched for age and LS BMD, selected from the same database.

RESULTS

The study population included 342 women. The two groups were similar in age, and aBMD at the LS and total hip. Femoral neck aBMD was lower in cases than in taller women. In contrast, TBS was higher in women with short stature than in their taller counterparts (1.347 ± 0.102 vs. 1.250 ± 0.110; p < 0.001). Bone mineral apparent density (BMAD) and the LS TBS-adjusted BMD T-score were also significantly higher in shorter than in taller women. From the entire cohort, 121 women (67 cases) were osteoporotic by aBMD determinations. Among these subjects, TBS was also greater in cases (1.303 ± 0.103) than in women with standard height (1.190 ± 0.099; p < 0.001). Despite being considered osteoporotic, 36% of short women, but none of the taller ones, had a normal TBS.

CONCLUSIONS

TBS can be a useful adjunct to aBMD for assessing bone quality in short women, in whom aBMD measurement tends to read lower, and, thus could overestimate fracture risk.

Trabecular bone score and bone mineral density reference data for women aged 20-70 years and the effect of local reference data on the prevalence of postmenopausal osteoporosis: a cross-sectional study from Sri Lanka

This paper describes age-specific BMD and TBS data of Sri Lankan women aged 20-70 years. No significant change of TBS and BMDs were seen between 20 and 50 years but a rapid decline was seen between 50 and 70 years. Prevalence of osteoporosis showed a marked difference when local reference data were used instead of manufacture provided data.

INTRODUCTION

It is recommended that country-specific reference data are used when estimating diagnostic and therapeutic thresholds in osteoporosis. This study estimated normative BMD and TBS reference data for women aged 20-70 in Sri Lanka and the effect of local reference data on the diagnosis of osteoporosis among postmenopausal women.

METHODOLOGY

A group of healthy community-dwelling women (n = 355) aged 20-70 was recruited from Galle district in the Southern province in Sri Lanka using stratified random sampling method. They underwent DXA adhering to the manufacturer's protocol and regional BMDs and TBS of the lumbar spine were measured.

RESULTS

The highest mean BMD in the spine (0.928 g/cm²) was seen in 20-29 age group while there was a delay in achieving the peak BMD in the femoral neck (0.818 g/cm²) and total hip (0.962 g/cm²) regions(40-49 years). BMDs showed only a mild change between 20 and 49 years but a rapid decline was seen after 50 years (spine 0.013, femoral neck 0.012, and total hip 0.011 g/cm² per year). The highest TBS was seen in 20-29 age group (1.371) and TBS trend with age was parallel to spine BMD. When the reference data provided by the manufacturer was used, 37% of postmenopausal women were found to have osteoporosis but this value changed to 17.6% when the local reference data were used.

CONCLUSION

We found a significant difference in the prevalence of osteoporosis when the local reference values were used instead of data provided by the manufacturer. However, representative data from more centers and fracture data are required before a recommendation to use local instead of international reference data can be stated.

Connexin 43 hemichannels protect bone loss during estrogen deficiency

Estrogen deficiency in postmenopausal women is a major cause of bone loss, resulting in osteopenia, osteoporosis, and a high risk for bone fracture. Connexin 43 (Cx43) hemichannels (HCs) in osteocytes play an important role in osteocyte viability, bone formation, and remodeling. We showed here that estrogen deficiency reduced Cx43 expression and HC function. To determine if functional HCs protect osteocytes and bone loss during estrogen deficiency, we adopted an ovariectomy model in wild-type (WT) and two transgenic Cx43 mice: R76W (dominant-negative mutant inhibiting only gap junction channels) and Cx43 Δ130–136 (dominant-negative mutant compromising both gap junction channels and HCs). The bone mineral density (BMD), bone structure, and histomorphometric changes of cortical and trabecular bones after ovariectomy were investigated. Our results showed that the Δ130–136 transgenic cohort had greatly decreased vertebral trabecular bone mass compared to WT and R76W mice, associated with a significant increase in the number of apoptotic osteocyte and empty lacunae. Moreover, osteoclast surfaces in trabecular and cortical bones were increased after ovariectomy in the R76W and WT mice, respectively, but not in ∆130–136 mice. These data demonstrate that impairment of Cx43 HCs in osteocytes accelerates vertebral trabecular bone loss and increase in osteocyte apoptosis, and further suggest that Cx43 HCs in osteocytes protect trabecular bone against catabolic effects due to estrogen deficiency.

Channels that form between cells and their extracellular environment help protect bone tissue from the damage wrought by low estrogen levels, a major cause of bone loss in post-menopausal women. Jean Jiang from the UT Health San Antonio and colleagues showed that depleting the estrogen hormone in mouse bone cells reduced levels of connexin 43 and impaired the protein’s ability to forms pores known as ‘hemichannels’. The researchers surgically removed the ovaries of various mouse strains to induce estrogen deficiencies. They found that transgenic mice without working hemichannels had reduced bone mass compared to normal mice or mice that could make hemichannels but lacked the ability for those channels to come together to form complete passageways. The findings highlight the importance of connexin 43 hemichannels in protecting bone tissue against osteoporosis.

Older Age and Higher Body Mass Index Are Associated With a More Degraded Trabecular Bone Score Compared to Bone Mineral Density

Trabecular bone score (TBS) may detect subjects with a more degraded microarchitecture but whose bone mineral density (BMD) reflects normal or osteopenia. The purpose of this study was to evaluate whether age and body sizes were associated with the discordance between BMD and TBS. We analyzed BMD and TBS in 1505 Korean women over 40 yr of age who had no history of osteoporotic fractures or conditions that affect bone metabolism. We considered 3 groups to have TBS values that reflected a more degraded TBS than their BMD values: (1) normal BMD but partially degraded TBS, (2) normal BMD but degraded TBS, and (3) osteopenia but degraded TBS. We compared subjects in these 3 groups with other subjects in terms of age and body sizes, and used multivariable logistic regression to analyze the odds ratios (ORs) for the occurrence of a more degraded TBS than their BMD level using age and body mass index (BMI). One hundred sixty subjects (10.6%) were found to have a more degraded TBS than their BMD level; these subjects were older, heavier, and had higher BMIs than the other subjects. Age (OR: 1.038, 95% confidence interval: 1.020-1.057, p< 0.001) and BMI (OR: 1.223, 95% confidence interval: 1.166-1.283, p< 0.001) were statistically significant in the multivariable analysis for the occurrence of this feature. Women with a more degraded TBS than their BMD level are older and have higher BMIs than the other subjects. It may be helpful to consider the possibility of trabecular bone degradation when clinically evaluating fracture risk in patients who are older or who have high BMIs with normal BMD or osteopenia.

Lower Trabecular Bone Score is Associated With the Use of Proton Pump Inhibitors

INTRODUCTION

Trabecular bone score (TBS) provides indirect indices of trabecular microarchitecture and bone quality. Several studies have evaluated the influence of proton pump inhibitors (PPIs) on bone mass and geometric parameters, but no studies have evaluated the influence of PPIs on TBS.

METHODS

We reviewed the medical records of 1505 women aged 40-89 yr who had bone mineral density (BMD) examinations as a part of the medical diagnosis and disease prevention program and who did not have osteoporotic fractures or conditions that could affect bone metabolism. Among these, we identified 223 women with exposure to PPIs and selected the same number of age- and body mass index (BMI)-matched control patients. We compared TBS and BMD between the PPI exposure group and the control group and performed multivariate regression analyses to determine whether TBS and BMDs are associated with age, BMI, and PPIs exposure. We also examined whether TBS and BMDs are associated with PPIs exposure timing (current, recent, and past).

RESULTS

TBS and BMDs were significantly lower in the PPI exposure group than in the control group. In a multivariable linear regression analysis, TBS was significantly associated with age (p < 0.001) and PPI exposure (p = 0.02). In addition, all BMDs were found to be significantly associated with age, BMI, and PPI exposure. Lower TBS was associated with current PPIs use (p = 0.005), but not with recent or past PPIs usage. However, the influence of PPI exposure timing on the BMDs was not consistent between BMD measurement sites.

CONCLUSIONS

This study found that TBS is lower in subjects with PPIs exposure than in controls. The association of lower TBS with current PPIs use suggests that trabecular bone quality could be affected early by PPIs, and but the effect might be reversible.

TBS as a Tool to Differentiate the Impact of Antiresorptives onCortical and Trabecular Bone in Children With OsteogenesisImperfecta

INTRODUCTION/BACKGROUND

Osteogenesis imperfecta is a hereditary connective tissue disorder, resulting in low bone mass and high bone fragility. Dual-energy X-ray absorptiometry (DXA) and in adulthood also the trabecular bone score (TBS) are well established to assess bone health and fracture risk. The purpose of this investigation was to assess the usefulness of TBS in respect to different treatment regimes in children with osteogenesis imperfecta. Changes of areal bone mineral density (aBMD) and TBS using DXA scans of children treated with antiresorptive therapies were evaluated.

METHODOLOGY

DXA scans (aBMD, TBS) of 8 children with OI were evaluated. The scans were taken during a 1 yr period of treatment with bisphosphonates and during 1 yr pilot trial using denosumab. Changes of aBMD and TBS during both treatment regimens were compared.

RESULTS

During bisphosphonate treatment aBMD increased about 6.2%, while TBS increased about 2.1%. The difference between aBMD and TBS before and after bisphosphonate treatment was not significant (p = 0.25). During denosumab treatment aBMD increased around 25.1%, while TBS increased 6.7%. The change of aBMD was significant (p = 0.007), as was the difference between aBMD and TBS (p < 0.001).

CONCLUSIONS

Denosumab had a significant effect on both aBMD and TBS but was significantly more pronounced in aBMD. These results suggest a stronger effect of denosumab on cortical bone and the growth plate in comparison to bisphosphonates. Beside the lack of paediatric reference data and the small sample size, the results suggest TBS to be a useful tool for monitoring skeletal changes during development, growth, and antiresorptive therapy in children with OI.