Lumbar Spine Dual X-ray Absorptiometry Research Articles

Bone Marrow Adipose Tissue Is Increased in Postmenopausal Women With Postsurgical Hypoparathyroidism.

Suppression of bone turnover, greater trabecular volume, and normal-high normal all-site bone mineral density (BMD) are hallmarks of postsurgical hypoparathyroidism (HypoPT). Impairment in the trabecular microarchitecture with possible higher risk of vertebral fractures (VF) in women with postmenopausal HypoPT has also been described. Currently, no data on bone marrow adipose tissue (BMAT) are available in HypoPT. To assess BMAT by magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS) in postmenopausal women with chronic postsurgical HypoPT. This cross-sectional pilot study, conducted at an ambulatory referral center, included 29 postmenopausal women (mean age 66 ± 8.4 years) with postsurgical HypoPT and 31 healthy postmenopausal women (mean age 63 ± 8.5). Lumbar spine MRI was performed and BMAT was measured by applying PRESS sequences on the L3 body. Lumbar spine, femoral neck, and total hip BMD were measured by dual x-ray absorptiometry (DXA); site-matched spine trabecular bone score (TBS) was calculated by TBS iNsight (Medimaps, Switzerland); VF assessment was performed with lateral thoracic and lumbar spine DXA. Fat content (FC) and saturation level (SL%) were higher (P <.0001 and P <.001), while water content (W) was lower in HypoPT compared to controls (P <.0001). FC significantly correlated with years since menopause and body weight (P <.05) in HypoPT, while TBS negatively correlated with FC and SL% (P <.05) and positively with residual lipids (RL) and W (P <.05). We demonstrate for the first time that BMAT is increased in postmenopausal women with postsurgical hypoparathyroidism and negatively associated with trabecular microarchitecture.

Bone health evaluation in primary hyperparathyroidism using dual-energy X-ray absorptiometry and trabecular bone score.

Bone involvement in primary hyperparathyroidism (PHPT) is characterized by reduced bone mineral density (BMD) using dual X-ray absorptiometry (DXA). A hallmark of PHPT is BMD loss at cortical sites while trabecular bone remains relatively preserved. PHPT is associated with increased fracture risk at both trabecular and cortical skeletal sites, which cannot be explained based on BMD values alone. The application of the trabecular bone score (TBS), an index of the lumbar spine DXA bone microarchitecture, showed lower TBS values and increased risk of fractures in PHPT patients, independent of BMD. Although further prospective studies are needed, promising data have been published with the use of TBS and some advanced DXA-based imaging modalities in patients with PHPT.

Estimation of Whole-Body and Appendicular Lean Mass from Spine and Hip Dual Energy X-ray Absorptiometry: A Cross-Sectional Study.

Whole-body dual X-ray absorptiometry (DXA) accurately measures lean mass but is not routinely used in clinical practice. Hip and spine DXA are used in the diagnosis of osteoporosis, and with the common co-occurrence of sarcopenia with osteoporosis, regional DXA scans provide an opportunity for assessment of lean mass. The aim of this study is to develop predictive equations for the estimation of whole-body lean mass (WBLM), appendicular lean mass (ALM) and whole-body fat mass (WBFM) from regional DXA scans. A total of 2427 participants (ages 20-96year; 57.7% men) from the Geelong Osteoporosis Study who underwent both regional and whole-body DXA were included in the analysis. Using forward stepwise multivariable linear regression, percentage fat (spine%fat, hip%fat) values from lumbar spine and femoral neck DXA were used in combination with clinical data to develop and validate equations for the estimation of WBLM, WBFM and ALM. Mean age was 53.5year (± 19.2), weight 78.2kg (± 15.4), height 169.6cm (± 9.4), WBLM 50.4kg (± 11.1), ALM 22.8kg (± 5.4) and WBFM 24.3kg (± 10.4). Spine%fat (r = 0.21) and hip%fat (r = - 0.34) were correlated with whole-body lean mass (p < 0.001). Final predictive equations included age, sex, weight, height, spine%fat, and hip%fat and possessed high predictive value (Adj R2 0.91-0.94, RMSE 1.60-2.84kg). K-fold cross-validation methods produced median root mean square error (RMSE) ranging from 1.59 to 2.81kg for the three models. Regional DXA scans of the spine and hip can be used to estimate whole-body and appendicular lean mass, to assist in the identification of low muscle mass.

Fracture Risk Assessment: An Update.

Our ability to accurately identify high fracture risk in individuals has improved as the volume of clinical data has expanded and fracture risk assessment tools have been developed. Given its accessibility, affordability, and low radiation exposure, dual x-ray absorptiometry (DXA) remains the standard for osteoporosis screening and monitoring response to treatment. The trabecular bone score (TBS) is a DXA software add-on that uses lumbar spine DXA imaging to produce an output that correlates with bone microarchitecture. It has been identified as an independent fracture risk factor and may prove useful in further stratifying fracture risk among those with a bone mineral density (BMD) in the osteopenic range (-1.0 to -2.4 standard deviations), in those with low-energy fractures but normal or only mildly low BMD, or in those with conditions known to impair bone microarchitecture. Fracture risk assessment tools, including the Fracture Risk Assessment Tool (FRAX), Garvan fracture risk calculator, and QFracture, evaluate the impact of multiple clinical factors on fracture risk, even in the absence of BMD data. Each produces an absolute fracture risk output over a defined interval of time. When used appropriately, these enhance our ability to identify high-risk patients and allow us to differentiate fracture risk among patients who present with similar BMDs. For challenging clinical cases, a combined approach is likely to improve accuracy in the identification of high-risk patients who would benefit from the available osteoporosis therapies.

Does Quantitative Ultrasound at the Calcaneus Predict an Osteoporosis Diagnosis in Postmenopausal Women from the Silesia Osteo Active Study?

The aims of the study were to assess the clinical conformity between quantitative ultrasound (QUS) and densitometry with use of the standard World Health Organization T-score thresholds to determine optimal diagnostic cutoff values for QUS T-scores in different age groups. Three hundred sixty-five postmenopausal Caucasian women were enrolled into the study and divided into two age groups (<65 y and ≥65 y). Skeletal status was assessed using QUS measurements at the calcaneus and bone densitometry at the spine and proximal femur (Hologic Explorer, Bedford, MA, USA). QUS measurement results expressed as the stiffness index (SI) correlated significantly with both femoral neck bone mineral density (r = 0.51, p < 0.0001) and lumbar spine bone mineral density (r = 0.52, p < 0.0001). On the basis of receiver operating characteristic curve analyses, the thresholds for correspondence between QUS T-score values and T-score –2.5SD in dual X-ray absorptiometry (DXA) were established. They ranged between –1.63SD and –1.70SD in relation to femoral neck DXA and between –1.22SD and –1.51SD in relation to lumbar spine DXA, depending on age category. In conclusion, the study described here confirmed that QUS measurements at the calcaneus may provide information comparable to DXA examinations at the femoral neck and lumbar spine in postmenopausal women.

Bone mineral density and fracture risk in adult patients with hypophosphatasia

SummaryIn adult hypophosphatasia (HPP) patients, elevated lumbar spine dual X-ray absorptiometry (DXA) values are associated with markers of disease severity and disease-specific fracture risk while femoral bone mineral density (BMD), being largely unaffected by the disease severity, may still be useful to monitor other causes of increased fracture risk due to low BMD.IntroductionHypophosphatasia (HPP) is a rare inherited metabolic disorder due to deficient activity of the tissue-nonspecific alkaline phosphatase (TNAP). Clinical manifestation in adult HPP patients is manifold including an increased risk for fractures, but data regarding clinical significance of DXA measurement and associations with fracture risk and disease severity is scarce.MethodsRetrospective single-center analysis of DXA scans in patients with confirmed HPP (documented mutation, clinical symptoms, low alkaline phosphatase activity). Further data evaluation included disease-related fractures, laboratory results (alkaline phosphatase, pyridoxalphosphate, phosphoethanolamine), and medical history.ResultsAnalysis included 110 patients (84 female, mean age of 46.2 years) of whom 37.3% (n = 41) were harboring two mutations. Average T-Score level at the lumbar spine was − 0.1 (SD 1.9), and mean total hip T-Score was − 1.07 (SD 0.15). Both lower ALP activity and higher substrate levels (pyridoxalphosphate and phosphoethanolamine) were significantly correlated with increased lumbar spine T-Score levels (p < 0.001) while BMD at the hip was not affected by indicators of disease severity. Increased lumbar spine BMD was significantly associated with an increased risk for HPP-related fractures, prevalent in 22 (20%) patients (p < 0.001) with 21 of them having biallelic mutations.ConclusionBMD in adult HPP patients is not systematically reduced. Conversely, increased lumbar spine BMD appears to be associated with severely compromised mineralization and increased risk for HPP-related fractures while BMD at the hip appears unaffected by indicators of disease severity, suggesting suitability of this anatomic location for assessing and discerning disorders with increased fracture risk owing to reduced BMD like osteoporosis.Trial registration numberGerman register for clinical studies (DRKS00014022)Date of registration02/10/2018 – retrospectively registered

Pathophysiology of growth hormone secretion disorders and their impact on bone microstructure as measured by trabecular bone score.

This article is focused on endocrine-mediated osteoporosis caused by growth hormone (GH) disorders; adult GH deficiency and acromegaly. GH and insulin like growth factor-1 (IGF-1) stimulate linear bone growth through complex hormonal interactions and activates epiphyseal prechondrocytes. GH, via receptor activator of nuclear factor-kappaB (RANK), its ligand (RANK-L), and the osteoprotegerin system, stimulates production of osteoprotegerin and its accumulation in bone matrix. Malfunction of this mechanism, could lead to specific bone impairment. However, the primary problem of bone disease in GH secretion disorders is the primary prevention of osteoporotic fractures, so it is important to determine bone quality that better reflects the patient's actual predisposition to fracture. A method estimating bone quality from lumbar spine dual X-ray absorptiometry (DXA) scans is trabecular bone score (TBS). TBS in addition to bone mineral density (BMD) is a promising predictor of the osteoporotic fracture risk in women with postmenopausal osteopenia. In acromegaly TBS better defines risk of fracture because BMD is normal or even increased. TBS helps to monitor the effect of growth hormone therapy. Despite these findings, TBS should not be used alone, but a comprehensive consideration of all fracture risk factors, BMD and bone turnover markers is necessary.

Trabecular bone quality is lower in adults with type 1 diabetes and is negatively associated with insulin resistance.

We evaluated TBS, a non-invasive method to evaluate trabecular bone quality at the lumbar spine, in adults with T1D compared to age-, sex-, and BMI-matched adults without diabetes. We calculated TBS from adults with T1D (n = 47) and controls (n = 47) who had a lumbar spine dual x-ray absorptiometry (DXA) at their third visit (2006-2009) of the ongoing "Coronary Artery Calcification in Type 1 Diabetes (CACTI) Study." The linear relationships of TBS and bone mineral density (BMD) with hemoglobin A1c, blood pressure, lipids, and insulin resistance were evaluated using Pearson's correlation coefficient. Multiple linear regression was used to test the association of TBS with sex and diabetes while adjusting for other potential confounders. TBS was significantly lower in adults with T1D compared to controls (1.42 ± 0.12 vs 1.44 ± 0.08, p = 0.02) after adjusting for age, sex, current smoking status, and lumbar spine BMD, despite no difference in lumbar spine BMD between the groups. Components of the metabolic syndrome, including diastolic blood pressure, BMI, triglycerides, and insulin resistance were negatively correlated with TBS among patients with T1D. Trabecular bone score, an indirect measurement of trabecular bone quality, was lower in adults with T1D compared to controls. Components of metabolic syndrome and insulin resistance were associated with lower TBS in adults with T1D.

Is Trabecular Bone Score Valuable in Bone Microstructure Assessment after Gastric Bypass in Women with Morbid Obesity?

Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS) is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA) images and allows an indirect assessment of skeletal microarchitecture (MA). The aim of our study was to evaluate the changes in bone mineral density (BMD) and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB), over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 ± 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OH)D3) decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD) significantly decreased 13.53 ± 5.42% and 6.03 ± 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 ± 106 and 1.413 ± 85, respectively), and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = −0.41, p = 0.010), body fat (r = −0.465, p = 0.004) and greater body fat deposited in trunk (r = −0.48, p = 0.004), and positively with LSBMD (r = 0.433, p = 0.007), fat mass loss (r = 0.438, p = 0.007) and lean mass loss (r = 0.432, p = 0.008). In the regression analysis, TBS remained associated with body fat (β = −0.625, p = 0.031; R2 = 0.47). The fracture risk, calculated by FRAX® (University of Sheffield, Sheffield, UK), with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS.

Abaloparatide-SC improves trabecular microarchitecture as assessed by trabecular bone score (TBS): a 24-week randomized clinical trial

SummaryIn a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to one of three different doses of abaloparatide-SC, subcutaneous teriparatide, or placebo for 24 weeks, abaloparatide-SC resulted in improvements in skeletal microarchitecture as measured by the trabecular bone score.IntroductionSubcutaneous abaloparatide (abaloparatide-SC) increases total hip and lumbar spine bone mineral density and reduces vertebral and non-vertebral fractures. In this study, we analyzed the extent to which abaloparatide-SC improves skeletal microarchitecture, assessed indirectly by trabecular bone score (TBS).MethodsThis is a post hoc analysis of a phase 2 trial of 222 postmenopausal women with osteoporosis aged 55 to 85 years randomized to abaloparatide-SC (20, 40, or 80 μg), subcutaneous teriparatide (20 μg), or placebo for 24 weeks. TBS was measured from lumbar spine dual X-ray absorptiometry (DXA) images in 138 women for whom the DXA device was TBS software compatible. Assessments were made at baseline, 12 and 24 weeks. Between-group differences were assessed by generalized estimating equations adjusted for relevant baseline characteristics, and a pre-determined least significant change analysis was performed.ResultsAfter 24 weeks, TBS increased significantly by 2.27, 3.14, and 4.21% versus baseline in participants on 20, 40, and 80 μg abaloparatide-SC daily, respectively, and by 2.21% in those on teriparatide (p < 0.05 for each). The TBS in the placebo group declined by 1.08%. The TBS increase in each treatment group was significantly higher than placebo at 24 weeks (p < 0.0001 for each) after adjustment for age, BMI, and baseline TBS. A dose-response was observed at 24 weeks across the three doses of abaloparatide-SC and placebo (p = 0.02). The increase in TBS in the abaloparatide-SC 80 μg group was significantly greater than TPTD (p < 0.03).ConclusionsThese results are consistent with an effect of abaloparatide-SC to improve lumbar spine skeletal microarchitecture, as assessed by TBS.

Habitual levels of higher, but not medium or low, impact physical activity are positively related to lower limb bone strength in older women: findings from a population-based study using accelerometers to classify impact magnitude

SummaryThis study assessed the effect of accelerometry-measured higher impacts resulting from habitual weight-bearing activity on lower limb bone strength in older women. Despite higher impacts being experienced rarely in this population-based cohort, positive associations were observed between higher vertical impacts and lower limb bone size and strength.IntroductionWe investigated whether the benefit of habitual weight-bearing physical activity (PA) for lower limb bone strength in older women is explained by exposure to higher impacts, as previously suggested by observations in younger individuals.MethodsFour hundred and eight women from the Cohort for Skeletal Health in Bristol and Avon (COSHIBA), mean 76.8 years, wore tri-axial accelerometers at the waist for a mean of 5.4 days. Y-axis peaks were categorised, using previously identified cutoffs, as low (0.5–1.0 g), medium (1.0–1.5 g), and higher (≥1.5 g) impacts. Mid and distal peripheral quantitative computed tomography scans of the tibia and radius were performed, as were hip and lumbar spine Dual X-ray Absorptiometry (DXA) scans. Regressions between (log transformed) number of low, medium and high impacts, and bone outcomes were adjusted for artefact error grade, age, height, fat and lean mass and impacts in other bands.ResultsEight thousand eight hundred and nine (4047, 16,882) low impacts were observed during the measurement week, 345 (99, 764) medium impacts and 42 (17, 106) higher impacts (median with 25th and 75th quartiles). Higher vertical impacts were positively associated with lower limb bone strength as reflected by cross-sectional moment of inertia (CSMI) of the tibia [0.042 (0.012, 0.072) p = 0.01] and hip [0.067 (0.001, 0.133) p = 0.045] (beta coefficients show standard deviations change per doubling in impacts, with 95 % confidence interval). Higher impacts were positively associated with tibial periosteal circumference (PC) [0.015 (0.003, 0.027) p = 0.02], but unrelated to hip BMD. Equivalent positive associations were not seen for low or medium impacts.ConclusionsDespite their rarity, habitual levels of higher impacts were positively associated with lower limb bone size and strength, whereas equivalent relationships were not seen for low or medium impacts.

P-074: Food practices and use of complementary & alternative medicine (CAM) in pediatric inflammatory bowel disease (IBD) patients in Singapore

P-074: Food practices and use of complementary & alternative medicine (CAM) in pediatric inflammatory bowel disease (IBD) patients in Singapore

P-073: Exclusive enteral nutrition in the treatment of children with Crohn’s disease in the Netherlands: a questionnaire survey amongst dietitians

P-073: Exclusive enteral nutrition in the treatment of children with Crohn’s disease in the Netherlands: a questionnaire survey amongst dietitians

A4.1 Lumbar bone mineral density and long-term cardiovascular risk – a cross-sectional study

Background and ObjectivesOsteoporosis and cardiovascular morbidity are strongly associated with age and menopause. The study aimed to evaluate the association of cardiovascular risk (CVR), estimated using SCORE charts, with BMD...

Osteoporosis and Osteoarthritis, Rheumatoid Arthritis and Spondylarthropathies

Osteoporosis (OP) commonly occurs in the setting of inflammatory arthritis, whereas there is an inverse relationship with osteoarthritis (OA). We review the recent updates in epidemiology and pathophysiology of OP relating to several arthridities. In ankylosing spondylitis, lateral lumbar spine dual x-ray absorptiometry is better at detecting osteoporosis compared with the AP view and patients receiving treatment with anti- tumor necrosis factor medications had lower levels of bone turnover markers. With regard to rheumatoid arthritis, anticitrullinated peptide positivity without clinical arthritis as well as higher levels of interleukin-6 is associated with decreased bone mineral density and polymorphisms in the vitamin D receptor in RA patients may predispose to OP. With regard to OA, results from the Global Longitudinal Study of Osteoporosis in Women study and several radiological studies suggest that differences in the distribution of bone mass at the femoral neck may account for the inverse relationship of OA and OP, and several studies suggest that OA and OP have opposing cytokine and bone metabolism marker profiles.

Effects of anti-resorptive agents on trabecular bone score (TBS) in older women

We evaluated the longitudinal effects of anti-resorptive agents (534 treated women vs. 1,150 untreated) on lumbar spine bone mineral density (BMD) and trabecular bone score (TBS). TBS was responsive to treatment in women over age 50. The treatment-related increase in TBS was less than the increase in BMD, which is consistent with bone texture preservation. In addition to inducing an increase in BMD, anti-resorptive agents also help to preserve bone architecture. TBS, a new gray-level texture measurement, correlates with 3D parameters of bone micro-architecture independent of BMD. Our objective was to evaluate the longitudinal effects of anti-resorptive agents on lumbar spine BMD and TBS. Women (≥ 50 years), from the BMD program database for the province of Manitoba, Canada, who had not received any anti-resorptive drug prior to their initial dual X-ray absorptiometry (DXA) exam were divided into two groups: untreated, those without any anti-resorptive drug over the course of follow-up, and treated, those with a non-estrogen anti-resorptive drug (86 % bisphosphonates, 10 % raloxifene, and 4 % calcitonin). Lumbar spine TBS was calculated for each lumbar spine DXA examination. Changes in TBS and BMD between baseline and follow-up (mean follow-up 3.7 years), expressed in percentage per year, were compared between the two groups. A total of 1,150 untreated women and 534 treated women met the inclusion criteria. Only a weak correlation was seen between BMD and TBS in either group. Significant intergroup differences in BMD change and TBS change were observed over the course of follow-up (p < 0.001). Similar mean decreases in BMD and TBS (-0.36 %/year and -0.31 %/year, respectively) were seen for untreated subjects (both p < 0.001). Conversely, treated subjects exhibited a significant mean increase in BMD (+1.86 %/year, p < 0.002) and TBS (+0.20 %/year, p < 0.001). TBS is responsive to treatment with non-estrogen anti-resorptive drug therapy in women over age 50. The treatment-related increase in TBS is less than the increase in BMD, which is consistent with bone texture preservation.

Inflammatory diseases and bone health in children

Chronic pediatric inflammatory diseases are associated with low bone mass and fractures during childhood, and may hasten the onset of osteoporosis later in life. Proinflammatory cytokines and glucocorticoid therapy are likely key factors that impair bone accrual, along with downstream effects including malnutrition, pubertal delay, low muscle mass and physical inactivity. Studies have used advanced imaging to characterize deficits in trabecular and cortical bone and have evaluated the 'functional muscle-bone unit'. In general, bone strength in the appendicular skeleton is compromised because of thinner cortical bone, with a low periosteal circumference and a normal or expanded endosteal circumference. Low muscle mass likely contributes to, but does not fully account for bone deficits. Systematic efforts to define the incidence and prevalence of bone fragility in children with inflammatory conditions demonstrated that vertebral fractures occur in a significant minority of patients in association with high disease activity, glucocorticoid use, and weight gain. Lumbar spine dual X-ray absorptiometry does not consistently distinguish children with and without vertebral fractures. In children with inflammatory diseases, the documented elevated fracture risk and bone structural abnormalities highlight the need for additional research to better define methods for the assessment and prevention of bone fragility.

Should risk of bone fragility restrict weight control for other health reasons in postmenopausal women? – A ten year prospective study

Background The aim of the present study was to investigate the health risks of excess body weight in the light of its protective effects on bone fragility. Methods Femoral neck and lumbar spine dual X-ray absorptiometry was performed for 1970 Finnish women with a mean baseline age of 58.8 years (range 53.1–65.7 years) in 1994 and 2004. Women were categorized according to baseline BMI into normal <25 kg/m2, overweight 25–29.9 kg/m 2 and obese ≥30 kg/m 2. Weight change (kg) was categorized into tertiles. Co-morbidities, not allowed to be present at baseline, was based on self-reports. Osteoporosis was defined as femoral neck or spinal (L2–L4) T-score <−2.5 SD at 10-year follow-up or <−2.0 SD + low trauma energy follow-up fracture. Uni- and multivariate logistic regression models were used to estimate the 10-year risk of incident health disorders. Adjustment for age, number of diseases, alcohol intake and smoking was used in the multivariate models. Results Obesity (Ob) and overweight (Ow) were related with higher 10-year risk of hypertension (OR = 2.6 (Ob)/OR = 1.7 (Ow), p < 0.001), coronary artery disease (OR = 1.6, p < 0.05/OR = 1.2, p = NS), diabetes (OR = 11.7/OR = 5.3, p < 0.001), osteoarthritis (OR = 1.4, p < 0.05/OR = 1.1, p = NS), chronic back pain (OR = 1.6, p = 0.007/OR = 1.2, p = NS) and poor self-rated health (OR = 2.4, p < 0.05/OR = 1.5, p = NS) and lower risk of osteoporosis (OR = 0.13/OR = 0.28, p < 0.001). Weight change of less than +1 kg was associated 1.8 and 2.6 times lower 10-year risk of having hypertension and breast cancer than weight change over 6.2 kg. Among obese women the absolute risk increase of hypertension was 17%, of diabetes 12%, and absolute risk reduction of osteoporosis 14% in comparison to BMI <25 kg/m 2. Conclusions Health related risks of high BMI outweigh its protective effects on bone. Weight gain increases the risk hypertension and breast cancer.

Hounsfield Units for Assessing Bone Mineral Density and Strength: A Tool for Osteoporosis Management

Measurements obtained from clinical computed tomography examinations may yield information leading to the diagnosis of decreased bone mineral density, without added expense to the patient. The purpose of the present study was to determine if Hounsfield units, a standardized computed tomography attenuation coefficient, correlate with bone mineral density and compressive strength. Twenty-five patients (including eighteen female and seven male patients with a mean age of 71.3 years) undergoing both lumbar spine dual x-ray absorptiometry scans and computed tomography imaging were evaluated to determine if Hounsfield units correlated with bone mineral density and T-scores. Normative data were generated from lumbar spine computed tomography examinations for eighty consecutive trauma patients and were stratified by age and sex. Separately, polyurethane foam blocks of varying densities were imaged with computed tomography and were subjected to mechanical testing to determine compressive strength. Compressive strength values and Hounsfield units were analyzed for correlation. Significant correlations were found between Hounsfield units and bone mineral density, age, and T-scores and between Hounsfield units and compressive strength (p < 0.001). Hounsfield units obtained from clinical computed tomography scans that are made for other purposes correlate with dual x-ray absorptiometry scores as well as compressive strengths based on osseous models and potentially provide an alternative method for determining regional bone mineral density at no additional cost to the patient. The information could conceivably be applied toward fracture risk assessment, diagnosis of osteoporosis, and early initiation of needed treatment.

Trabecular Bone Score (TBS) the new parameter of 2D texture analysis for the evaluation of 3D bone micro architecture status.

Trabecular bone score (TBS) is a recently-developed analytical tool that performs novel grey-level texture measurements on lumbar spine dual X-ray absorptiometry (DXA) images, and thereby captures information relating to trabecular microarchitecture. In order for TBS to usefully add to bone mineral density (BMD) and clinical risk factors in osteoporosis risk stratification, it must be independently associated with fracture risk, readily obtainable, and ideally, present a risk which is amenable to osteoporosis treatment. This paper summarizes a review of the scientific literature performed by a Working Group of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis. Low TBS is consistently associated with an increase in both prevalent and incident fractures that is partly independent of both clinical risk factors and areal BMD (aBMD) at the lumbar spine and proximal femur. More recently, TBS has been shown to have predictive value for fracture independent of fracture probabilities using the FRAX® algorithm. Although TBS changes with osteoporosis treatment, the magnitude is less than that of aBMD of the spine, and it is not clear how change in TBS relates to fracture risk reduction. TBS may also have a role in the assessment of fracture risk in some causes of secondary osteoporosis (e.g., diabetes, hyperparathyroidism and glucocorticoid-induced osteoporosis). In conclusion, there is a role for TBS in fracture risk assessment in combination with both aBMD and FRAX.