Effect of soft tissue noise on trabecular bone score in postmenopausal women with diabetes: A cross sectional study

Bone microstructure and TBS in diabetes: what have we learned? A narrative review

Diabetes is associated with an increased risk of fracture. Areal bone mineral density (aBMD), the most reliable indicator of fracture risk in healthy adults, is low in patients with type 1 diabetes mellitus but normal or high in patients with type 2 diabetes mellitus. Most trabecular and cortical parameters measured by high-resolution peripheral quantitative computed tomography (HR-pQCT) are lower in type 1 diabetes and higher in type 2 diabetes, in parallel with aBMD. In contrast, lumbar spine trabecular bone score (TBS) has been reported to be lower in women with both type 1 and type 2 diabetes. The discordance between improved bone microstructure and degraded TBS reflects the effect of central obesity (currently the subject of a revision to the TBS algorithm). Meanwhile, evidence supports use of TBS in conjunction with aBMD and/or FRAX for improved fracture prediction in patients with type T2D. This position paper, on behalf of the Bone and Diabetes Working Group of the International Osteoporosis Foundation, summarizes alterations in bone microarchitecture measured by HR-pQCT in diabetes. It also addresses the technical and clinical considerations of the trabecular bone score, particularly discussing the significance of this measurement in individuals with diabetes and the influence of abdominal fat.

Age-related trends in trabecular bone scores and bone mineral density in Chinese men with type 2 diabetes mellitus: a cross-sectional study

Patients with Type 2 diabetes mellitus(T2DM) typically have an average or higher bone mineral density (BMD) but are at a significantly higher risk of fracture than patients without diabetes. Trabecular bone score (TBS) is a textural index derived from pixel gray-level variations in lumbar spine DXA image, which has been introduced as an indirect measure of bone quality. This study aimed to discuss the trends and annual rates of change in BMD and TBS with age in Chinese men with T2DM and men without diabetes mellitus. Lumbar spine(LS) TBS was significantly lower in males with T2DM compared to men without diabetes(1.279 ± 0.117 vs. 1.299 ± 0.090, P = 0.005). However, TBS in men with T2DM peaked around age 60, which occurred later and was lower than the peak observed in men without diabetes, who reached their peak TBS around age 50 (1.294 ± 0.126 vs. 1.328 ± 0.088). Femoral neck, total hip, and lumbar spine BMD in men with T2DM were not significantly different from those in men without diabetes. The results showed that both men with or without T2DM exhibited the lowest annual rates of change in TBS at 66-75 years of age, with values of -1.05%(P < 0.001) and - 0.90%(P < 0.001), respectively. Patients with great glycemic control demonstrated higher TBS and BMD. Men with T2DM have later and lower peak TBS and faster bone loss, suggesting that diabetes may negatively impact bone microarchitecture and mineralization.

Updated practice guideline for dual-energy X-ray absorptiometry (DXA)

The introduction of dual-energy X-ray absorptiometry (DXA) technology in the 1980s revolutionized the diagnosis, management and monitoring of osteoporosis, providing a clinical tool which is now available worldwide. However, DXA measurements are influenced by many technical factors, including the quality control procedures for the instrument, positioning of the patient, and approach to analysis. Reporting of DXA results may be confounded by factors such as selection of reference ranges for T-scores and Z-scores, as well as inadequate knowledge of current standards for interpretation. These points are addressed at length in many international guidelines but are not always easily assimilated by practising clinicians and technicians. Our aim in this report is to identify key elements pertaining to the use of DXA in clinical practice, considering both technical and clinical aspects. Here, we discuss technical aspects of DXA procedures, approaches to interpretation and integration into clinical practice, and the use of non-bone mineral density measurements, such as a vertebral fracture assessment, in clinical risk assessment.

Association of trabecular bone score corrected for tissue thickness with glucose metabolism in acromegaly

Introduction

Acromegaly is associated with increased vertebral fracture (VF) risk regardless of bone mineral density (BMD). However, the vertebral trabecular compartment is still low; a possible contributor to this may be impaired glucose metabolism (GM) which frequently complicates acromegaly. Additionally, soft tissue thickness may confound bone imaging in acromegaly patients.

Objective

This study aims to assess the association of GM with BMD, trabecular bone score adjusted for BMI (TBSBMI), and trabecular bone score adjusted for tissue thickness (TBSTT) among acromegaly subjects.

Patients and methods

A cross-sectional study was performed among 70 consecutive acromegaly patients (24 male/46 female, aged 55.1 years) divided in two subgroups: abnormal GM (n = 35) and normal GM (n = 35). Using DXA, BMD, TBSBMI, TBSTT, and VF screening were performed.

Results

In all subjects, TBSTT was higher (mean 9.5%) than TBSBMI. Abnormal GM subjects had lower TBSBMI (1.166 ± 0.15) than normal GM subjects (1.232 ± 0.12; p < 0.05). No between-group difference in TBSTT or BMD was observed. In a multiple regression model, the best predictor of TBSTT was HbA1c (p = 0.002). None of the DXA measures or GM parameters was a significant predictor of VF (n = 7).

Conclusion

The abnormal GM acromegaly subjects had lower TBSBMI than those with normal GM. TBSTT was higher than TBSBMI, and no between-group difference based on GM status was observed. TBSTT was significantly associated with GM parameters, notably HbA1c. The relationship of TBSTT with GM parameters may imply an effect of GM on trabecular bone microstructure in patients with acromegaly; a further study is indicated.

Effect of abdominal tissue thickness on trabecular bone score and fracture risk in adults with diabetes: the Manitoba BMD registry

Individuals with type 2 diabetes have lower trabecular bone score (TBS) and increased fracture risk despite higher bone mineral density. However, measures of trabecular microarchitecture from high-resolution peripheral computed tomography are not lower in type 2 diabetes. We hypothesized that confounding effects of abdominal tissue thickness may explain this discrepancy, since central obesity is a risk factor for diabetes and also artifactually lowers TBS. This hypothesis was tested in individuals aged 40 years and older from a large DXA registry, stratified by sex and diabetes status. When DXA-measured abdominal tissue thickness was not included as a covariate, men without diabetes had lower TBS than women without diabetes (mean difference -0.074, P < .001). TBS was lower in women with versus without diabetes (mean difference -0.037, P < .001), and men with versus without diabetes (mean difference -0.007, P = .042). When adjusted for tissue thickness these findings reversed, TBS became greater in men versus women without diabetes (mean difference +0.053, P < .001), in women with versus without diabetes (mean difference +0.008, P < .001), and in men with versus without diabetes (mean difference +0.014, P < .001). During mean 8.7 years observation, incident major osteoporotic fractures were seen in 7048 (9.6%). Adjusted for multiple covariates except tissue thickness, TBS predicted fracture in all subgroups with no significant diabetes interaction. When further adjusted for tissue thickness, HR per SD lower TBS remained significant and even increased slightly. In conclusion, TBS predicts fractures independent of other clinical risk factors in both women and men, with and without diabetes. Excess abdominal tissue thickness in men and individuals with type 2 diabetes may artifactually lower TBS using the current algorithm, which reverses after accounting for tissue thickness. This supports ongoing efforts to update the TBS algorithm to directly account for the effects of abdominal tissue thickness for improved fracture risk prediction.

Use of noninvasive imaging to identify causes of skeletal fragility in adults with diabetes: a review

Diabetes, a disease marked by consistent high blood glucose levels, is associated with various complications such as neuropathy, nephropathy, retinopathy, and cardiovascular disease. Notably, skeletal fragility has emerged as a significant complication in both type 1 (T1D) and type 2 (T2D) diabetic patients. This review examines noninvasive imaging studies that evaluate skeletal outcomes in adults with T1D and T2D, emphasizing distinct skeletal phenotypes linked with each condition and pinpointing gaps in understanding bone health in diabetes. Although traditional DXA-BMD does not fully capture the increased fracture risk in diabetes, recent techniques such as quantitative computed tomography, peripheral quantitative computed tomography, high-resolution quantitative computed tomography, and MRI provide insights into 3D bone density, microstructure, and strength. Notably, existing studies present heterogeneous results possibly due to variations in design, outcome measures, and potential misclassification between T1D and T2D. Thus, the true nature of diabetic skeletal fragility is yet to be fully understood. As T1D and T2D are diverse conditions with heterogeneous subtypes, future research should delve deeper into skeletal fragility by diabetic phenotypes and focus on longitudinal studies in larger, diverse cohorts to elucidate the complex influence of T1D and T2D on bone health and fracture outcomes.

Femoral bone mineral density at the time of hip fracture is higher in women with versus without type 2 diabetes mellitus: a cross-sectional study

PURPOSE

To compare femoral bone mineral density (BMD) levels in hip-fracture women with versus without type 2 diabetes mellitus (T2DM). We hypothesized that BMD levels could be higher in the women with T2DM than in controls and we aimed to quantify the BMD discrepancy associated with the presence of T2DM.

METHODS

At a median of 20 days after the occurrence of an original hip fracture due to fragility we measured BMD by dual-energy x-ray absorptiometry at the non-fractured femur.

RESULTS

We studied 751 women with subacute hip fracture. Femoral BMD was significantly higher in the 111 women with T2DM than in the 640 without diabetes: mean T-score between-group difference was 0.50, (95% CI from 0.30 to 0.69, P < 0.001). The association between the presence of T2DM and femoral BMD persisted after adjustment for age, body mass index, hip-fracture type, neurologic diseases, parathyroid hormone, 25-hydroxyvitamin D and estimated glomerular filtration rate (P < 0.001). For a woman without versus with T2DM, the adjusted odds ratio to have a femoral BMD T-score below the threshold of - 2.5 was 2.13 (95% CI from 1.33 to 3.42, P = 0.002).

CONCLUSIONS

Fragility fractures of the hip occurred in women with T2DM at a femoral BMD level higher than in control women. In the clinical assessment of fracture risk, we support the adjustment based on the 0.5 BMD T-score difference between women with and without T2DM, although further data from robust longitudinal studies is needed to validate the BMD-based adjustment of fracture risk estimation.

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.

Trabecular Bone Score (TBS) in Individuals with Type 2 Diabetes Mellitus: An Updated Review

Bone fragility is a complication of type 2 diabetes mellitus (T2DM) that has been identified in recent decades. Trabecular bone score (TBS) appears to be more accurate than bone mineral density (BMD) in diabetic bone disease, particularly in menopausal women with T2DM, to independently capture the fracture risk. Our purpose was to provide the most recent overview on TBS-associated clinical data in T2DM. The core of this narrative review is based on original studies (PubMed-indexed journals, full-length, English articles). The sample-based analysis (n = 11, N = 4653) confirmed the use of TBS in T2DM particularly in females (females/males ratio of 1.9), with ages varying between 35 and 91 (mean 65.34) years. With concern to the study design, apart from the transversal studies, two others were prospective, while another two were case-control. These early-post-pandemic data included studies of various sample sizes, such as: males and females (N of 245, 361, 511, and 2294), only women (N of 80, 96, 104, 243, 493, and 887), and only men (N = 169). Overall, this 21-month study on published data confirmed the prior profile of BMD-TBS in T2DM, while the issue of whether checking the fracture risk is mandatory in adults with uncontrolled T2DM remains to be proven or whether, on the other hand, a reduced TBS might function as a surrogate marker of complicated/uncontrolled T2DM. The interventional approach with bisphosphonates for treating T2DM-associated osteoporosis remains a standard one (n = 2). One control study on 4 mg zoledronic acid showed after 1 year a statistically significant increase of lumbar BMD in both diabetic and non-diabetic groups (+3.6%, p = 0.01 and +6.2%, p = 0.01, respectively). Further studies will pinpoint additive benefits on glucose status of anti-osteoporotic drugs or will confirm if certain glucose-lowering regimes are supplementarily beneficial for fracture risk reduction. The novelty of this literature research: these insights showed once again that the patients with T2DM often have a lower TBS than those without diabetes or with normal glucose levels. Therefore, the decline in TBS may reflect an early stage of bone health impairment in T2DM. The novelty of the TBS as a handy, non-invasive method that proved to be an index of bone microarchitecture confirms its practicality as an easily applicable tool for assessing bone fragility in T2DM.

Reduced High-Density Lipoprotein Cholesterol Is an Independent Determinant of Altered Bone Quality in Women with Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) is associated with an increased fracture risk. Our study aimed to explore differences in bone alterations between T2DM women and controls and to assess clinical predictors of bone impairment in T2DM. For this observational case control study, we recruited 126 T2DM female patients and 117 non-diabetic, age- and BMI-comparable women, who underwent clinical examination, routine biochemistry and dual-energy X-ray absorptiometry (DXA) scans for bone mineral density (BMD) and trabecular bone score (TBS) assessment-derived indexes. These were correlated to metabolic parameters, such as glycemic control and lipid profile, by bivariate analyses, and significant variables were entered in multivariate adjusted models to detect independent determinants of altered bone status in diabetes. The T2DM patients were less represented in the normal bone category compared with controls (5% vs. 12%; p = 0.04); T2DM was associated with low TBS (OR: 2.47, C.I. 95%: 1.19–5.16, p = 0.016) in a regression model adjusted for age, menopausal status and BMI. In women with T2DM, TBS directly correlated with plasma high-density lipoprotein cholesterol (HDL-c) (p = 0.029) and vitamin D (p = 0.017) levels. An inverse association was observed with menopausal status (p < 0.001), metabolic syndrome (p = 0.014), BMI (p = 0.005), and waist circumference (p < 0.001). In the multivariate regression analysis, lower HDL-c represented the main predictor of altered bone quality in T2DM, regardless of age, menopausal status, BMI, waist circumference, statin treatment, physical activity, and vitamin D (p = 0.029; R2 = 0.47), which likely underlies common pathways between metabolic disease and bone health in diabetes.

Glycemic Control and Bone in Diabetes

PURPOSE OF REVIEW

This review summarizes recent developments on the effects of glycemic control and diabetes on bone health. We discuss the foundational cellular mechanisms through which diabetes and impaired glucose control impact bone biology, and how these processes contribute to bone fragility in diabetes.

RECENT FINDINGS

Glucose is important for osteoblast differentiation and energy consumption of mature osteoblasts. The role of insulin is less clear, but insulin receptor deletion in mouse osteoblasts reduces bone formation. Epidemiologically, type 1 (T1D) and type 2 diabetes (T2D) associate with increased fracture risk, which is greater among people with T1D. Accumulation of cortical bone micro-pores, micro-vascular complications, and AGEs likely contribute to diabetes-related bone fragility. The effects of youth-onset T2D on peak bone mass attainment and subsequent skeletal fragility are of particular concern. Further research is needed to understand the effects of hyperglycemia on skeletal health through the lifecycle, including the related factors of inflammation and microvascular damage.

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.

Fracture prediction tools in diabetes

PURPOSE OF REVIEW

Type 1 (T1D) and 2 diabetes (T2D) are associated with increased risk of fracture independent of bone mineral density (BMD). Fracture risk prediction tools can identify individuals at highest risk, and therefore, most likely to benefit from antifracture therapy. This review summarizes recent advances in fracture prediction tools as applied to individuals with diabetes.

RECENT FINDINGS

The Fracture Risk Assessment (FRAX) tool, Garvan Fracture Risk Calculator (FRC), and QFracture tool are validated tools for fracture risk prediction. FRAX is most widely used internationally, and considers T1D (but not T2D) under secondary osteoporosis disorders. FRAX underestimates fracture risk in both T1D and T2D. Trabecular bone score and other adjustments for T2D-associated risk improve FRAX-based estimations. Similar adjustments for T1D are not identified. Garvan FRC does not incorporate diabetes as an input but does includes falls. Garvan FRC slightly underestimates osteoporotic fracture risk in women with diabetes. QFracture incorporates both T1D and T2D and falls as input variables, but has not been directly validated in individuals with diabetes.

SUMMARY

Further research is needed to validate and compare available fracture prediction tools and their performance in individuals with diabetes.

Evaluation of Quality and Bone Microstructure Alterations in Patients with Type 2 Diabetes: A Narrative Review

Bone fragility is a common complication in subjects with type 2 diabetes mellitus (T2DM). However, traditional techniques for the evaluation of bone fragility, such as dual-energy X-ray absorptiometry (DXA), do not perform well in this population. Moreover, the Fracture Risk Assessment Tool (FRAX) usually underestimates fracture risk in T2DM. Importantly, novel technologies for the assessment of one microarchitecture in patients with T2DM, such as the trabecular bone score (TBS), high-resolution peripheral quantitative computed tomography (HR-pQCT), and microindentation, are emerging. Furthermore, different serum and urine bone biomarkers may also be useful for the evaluation of bone quality in T2DM. Hence, in this article, we summarize the limitations of conventional tools for the evaluation of bone fragility and review the current evidence on novel approaches for the assessment of quality and bone microstructure alterations in patients with T2DM.