In Type-2 Diabetes Subjects Trabecular Bone Score is Better Associated with Carotid Intima-Media Thickness than BMD

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.

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.

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

BACKGROUND

Type 2 diabetes (T2D) is associated with increased fracture risk, despite similar or greater BMD compared to nondiabetics. TBS predicts fracture risk in T2D and nondiabetics. However, increased abdominal thickness, a common feature in T2D, may reduce TBS values.

AIM

To study the relationship among glycemic status, BMD and TBS, considering abdominal soft tissue thickness (STT) interference.

METHODS

Cross-sectional analysis of 493 women ≥65 years, with simultaneous DXA scans and HbA1c measures. STT and TBS (iNsight Software, v3.0) were derived from lumbar spine (LS) scans. Subjects were divided according to HbA1c levels: 1 (≥6.5%; n = 116), 2 (5.7-6.4%; n = 217) and 3 (≤5.6%; n = 160). Group 1 was further divided based on HbA1c and/or disease duration: 1a (HbA1c ≥ 7.5%; n = 42), 1b (HbA1c ≥ 6.5% and disease duration ≥5 years; n = 63) and 1c (HbA1c ≥ 7.5% and disease duration ≥5 years; n = 30).

FINDINGS

For the entire cohort, mean age, TBS, BMI and STT were 71.8 ± 6.0 years, 1.299 ± 0.101, 26.9 ± 4.1 kg/m², and 21.4 ± 2.9 cm, respectively. LS-BMD was similar among groups. BMD in hip sites and STT were higher in group 1. TBS was lower in patients with higher HbA1c (P = 0.020), with a mean TBS in groups 1, 2, and 3 of 1.280, 1.299 and 1.314, respectively. This difference remained after adjusting for age, LS-BMD and BMI (P = 0.010). After replacing BMI with STT, TBS differences were no longer significant (P = 0.270). The same was observed when subgroups 1a and 1b were compared to group 3. However, for subgroup 1c, TBS remained lower compared to group 3, even after adjusting for age, LS-BMD and STT, with a borderline P-value (1.275 vs. 1.308; P = 0.047).

CONCLUSION

Higher HbA1c levels were associated with greater BMD in hip sites, higher abdominal STT and lower TBS values. However, after including the STT in the adjustment, TBS differences among groups disappeared, except in women with higher HbA1c levels and longer disease duration.

DXA parameters, Trabecular Bone Score (TBS) and Bone Mineral Density (BMD), in fracture risk prediction in endocrine-mediated secondary osteoporosis

Osteoporosis, a disease characterized by low bone mass and alterations of bone microarchitecture, leading to an increased risk for fragility fractures and, eventually, to fracture; is associated with an excess of mortality, a decrease in quality of life, and co-morbidities. Bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA), has been the gold standard for the diagnosis of osteoporosis. Trabecular bone score (TBS), a textural analysis of the lumbar spine DXA images, is an index of bone microarchitecture. TBS has been robustly shown to predict fractures independently of BMD. In this review, while reporting also results on BMD, we mainly focus on the TBS role in the assessment of bone health in endocrine disorders known to be reflected in bone.

Lumbar spine bone mineral density and trabecular bone score-adjusted FRAX, but not FRAX without bone mineral density, identify subclinical carotid atherosclerosis

PURPOSE

Osteoporosis and atherosclerosis share common risk factors. Aim of this study was to test if FRAX (which is an algorithm that can identify subjects at risk of fracture), without or with BMD values, also adjusted for trabecular bone score (TBS) was able to identify subclinical atherosclerosis, evaluated by measurement of carotid intima media thickness (cIMT ≥ 0.9 mm) as compared to DXA values.

METHODS

Ninety postmenopausal women underwent DXA measurement and cIMT evaluation. For each patient, the FRAX algorithm for major osteoporotic fracture (M) and for hip fracture (H) without BMD was computed, together with FRAX with BMD and TBS-adjusted FRAX. Serum levels of osteoprotegerin, sRANKL, and interleukin-6 were also measured.

RESULTS

There were no differences in anthropometric parameters and cardiovascular risk factors between subjects with cIMT ≥ 0.9 mm (35% of subjects, group A) compared to those with cIMT < 0.9 mm (group B). The prevalence of osteoporosis and FRAX BMD, TBS-adjusted FRAX both for M and H were higher in group A compared to group B. The best ROC curves to identify subjects with a cIMT ≥ 0.9 mm were: lumbar spine T-score, with a threshold of - 2.5 SD (area under the curve, AUC 0.64; p = 0.02) with a sensibility of 50% and a specificity of 76%; TBS-adjusted FRAX H with a sensibility of 50% and a specificity of 72% (AUC 0.64; p = 0.01 with a threshold of 3%). Interleukin-6 positively correlated with FRAX BMD H and M.

CONCLUSIONS

FRAX without BMD does not identify subclinical carotid atherosclerosis, while lumbar spine T-score and TBS-adjusted FRAX H similarly detected it with higher specificity for T-score.

Association between trabecular bone score and type 2 diabetes: a quantitative update of evidence

Patients with type 2 diabetes have an increased risk of fracture despite having a higher areal bone mineral density. This meta-analysis showed that compared with controls, diabetic patients had a lower trabecular bone score (TBS) than non-diabetic individuals, suggesting that TBS can be a useful measurement for the assessment of fracture risk in diabetic patients.

INTRODUCTION

The association between type 2 diabetes and trabecular bone score (TBS) has not been clear. The present study sought to answer the specific question of whether patients with type 2 diabetes have a lower TBS than those without diabetes.

METHODS

Using electronic and manual search, we identified 12 studies that had examined the association between type 2 diabetes and TBS between 2013 and 2019. These studies involved 35,546 women and 4962 men aged 30 years and older. We extracted the mean and standard deviation of TBS for patients with and without diabetes. The synthesis of effect sizes was done by the random effects meta-analysis model.

RESULTS

Patients with diabetes had significantly lower TBS than those without diabetes, with standardized mean difference being - 0.31 (95% CI, - 0.45 to - 0.16). The difference was greater in women (- 0.50; 95% CI, - 0.69 to - 0.32) than in men (- 0.04; 95% CI, - 0.17 to 0.10). Compared with normal individuals, those with prediabetes had significantly lower TBS (d = - 0.13; 95% CI, - 0.23 to - 0.04; P = 0.005). There was heterogeneity between the studies, with the index of inconsistency (I²) ranging from 92% (in women) to 69.5% (in men).

CONCLUSION

Patients with type 2 diabetes have a lower TBS than non-diabetic individuals, suggesting that TBS can be a useful measurement for the assessment of fracture risk in diabetic patients.

Diagnosis and management of bone fragility in diabetes: an emerging challenge

Fragility fractures are increasingly recognized as a complication of both type 1 and type 2 diabetes, with fracture risk that increases with disease duration and poor glycemic control. Yet the identification and management of fracture risk in these patients remains challenging. This review explores the clinical characteristics of bone fragility in adults with diabetes and highlights recent studies that have evaluated bone mineral density (BMD), bone microstructure and material properties, biochemical markers, and fracture prediction algorithms (i.e., FRAX) in these patients. It further reviews the impact of diabetes drugs on bone as well as the efficacy of osteoporosis treatments in this population. We finally propose an algorithm for the identification and management of diabetic patients at increased fracture risk.

Fracture risk assessment in postmenopausal women with diabetes: comparison between DeFRA and FRAX tools

This study aimed to compare the performance of Fracture Risk Assessment Tool (FRAX) with that of Derived FRAX (DeFRA) in estimating fracture risk in a cohort of type-2 diabetes mellitus (T2DM) postmenopausal women. One hundred nineteen T2DM postmenopausal women and 118 consecutive healthy postmenopausal women were enrolled. Fracture risk was assessed with FRAX (adjusted or non- for trabecular bone score, TBS) and DeFRA. Bone mineral density (BMD) and TBS were evaluated by dual-energy X-ray absorptiometry (DXA). The outcome was the presence of vertebral/non-vertebral fragility fractures (FFs). T2DM women showed higher spinal BMD T-score (p < .05), but lower TBS (p < .05), than controls. Diabetic patients had higher prevalence of FFs compared to controls (p < .05), but no significant difference were found in the scores of any of the predictor tools. Differently, in the T2DM group, the scores of DeFRA, FRAX and adjusted-FRAX were significantly (p < .01 for all) higher in fractured compared with non-fractured women. DeFRA showed the best discriminative power among all fracture risk predictor tools (area under curves: DeFra: 0.89; adjusted FRAX: 0.80; non-adjusted FRAX: 0.73). In summary, all fracture risk assessment tools appeared to be effective in predicting bone fractures in T2DM postmenopausal women, with DeFRA showing a slightly better diagnostic accuracy.