Dual-energy X-ray Absorptiometry Bone Research Articles

Impact microindentation in men with impaired fasting glucose and type 2 diabetes.

Individuals with type 2 diabetes (T2DM) are at increased fracture risk, with bone mineral density (BMD) measurements underestimating risk. Impact microindentation (IMI), a technique that measures bone microindentation distances, expressed as bone material strength index (BMSi), may improve fracture risk estimation in individuals with T2DM. This study describes the relationship between BMSi and glycaemia status in men and makes a comparison with bone measures from dual energy X-ray absorptiometry (DXA). Participants were 340 men aged 33-96yr from the Geelong Osteoporosis Study. Impaired fasting glucose (IFG) was defined using fasting plasma glucose (FPG) between 5.5 and 6.9mmol/L. Diabetes was defined as FPG≥7.0mmol/L, use of antihyperglycemic medication and/or self-report. Two participants with type 1 diabetes were excluded. BMSi was measured using an OsteoProbe. Femoral neck (FNBMD) and lumbar spine (LSBMD) were measured using DXA (Lunar Prodigy) and trabecular bone score (TBS) was calculated (TBS iNsight Version 2.2). Using linear regression techniques, the relationship between glycaemia status and BMSi was evaluated, adjusting for other potential confounders (including lifestyle factors, clinical measurements and FNBMD). Glycaemia status was also considered as a binary variable (T2DM vs normoglycaemia and IFG). There were 234 (68.8%) men with normoglycaemia, 59 (17.4%) with IFG and 47 (13.8%) with diabetes. When considering glycaemia status as a binary variable, men with T2DM had lower mean BMSi compared to those without T2DM (normoglycaemia and IFG combined) (79.8; 95%CI 77.0-82.6 vs 83.0; 82.2-83.8 p=0.043) and this difference in BMSi was independent of FNBMD. No differences were observed for either FNBMD or LSBMD; however, TBS was lower (1.177; 1.121-1.233 vs 1.256; 1.240-1.272, p=0.015, independent of FNBMD). For glycaemia status considered in three groups, there were no differences in mean BMSi values between men with normoglycaemia, IFG and T2DM (82.9 (95%CI 82.0-83.8), 83.5 (81.8-85.2) and 79.8 (77.0-82.6), respectively; ANCOVA, p=0.104). Measures reflecting bone material properties and microarchitecture (BMSi and TBS) might be better than measures of bone mass (BMD) in identifying individuals with T2DM at risk of fracture.

Vertebral bone quality score predicts fragility fractures independently of bone mineral density

BACKGROUND Current evidence suggests that dual energy X-ray absorptiometry (DXA) scans –conventional method defining osteoporosis – is underutilized and, when used, may underestimate patient risk for skeletal fragility. It has recently been suggested that other imaging modalities may better estimate bone quality, such as the MRI-based vertebral bone quality (VBQ) score, previously associated with vertebral compression fracture risk in patients with spine metastases. PURPOSE To evaluate whether VBQ score is predictive of fragility fractures in a population with pre-existing low bone density and at high-risk for fracture. STUDY DESIGN/SETTING Retrospective single-center cohort. PATIENT SAMPLE Patients followed at a metabolic bone clinic for osteopenia/osteoporosis. OUTCOME MEASURES Radiographically-documented new- onset fragility fracture. METHODS Patients with a DXA and MRI scans at the time of consultation and ≥2-year follow-up were included. Details were gathered about patient demographics, health history, current medication use, and serological studies of kidney function and bone turnover. For each patient, VBQ score was calculated using T1-weighted lumbar MRI images. Univariable and multivariable analyses were used to identify the independent predictors of a new fragility fracture. To support the construct validity of VBQ, patient VBQ scores were compared to those in a cohort of 45 healthy adults. RESULTS Seventy-two (39.1%) study participants suffered fragility fractures, the occurrence of which was associated with higher VBQ score (3.50 vs 3.01; p<0.001), chronic glucocorticoid use (30.6% vs 15.2%; p=0.014), and a history of prior fragility fracture (36.1% vs 21.4%; p=0.030). Mean VBQ score across all patients in the study cohort was significantly higher than the mean VBQ score in the healthy controls (p<0.001). In multivariable analysis, new-onset fracture was independently associated with history of prior fracture (OR=6.94; 95% CI [2.48–19.40]; p<0.001), higher VBQ score (OR=2.40 per point; [1.30–4.44]; p=0.003), higher BMI (OR=1.09 per kg/m 2 ; [1.01–1.17]; p- 0.03), and chronic glucocorticoid use (OR=2.89; [1.03–8.17]; p=0.043). Notably, DXA bone mineral density (BMD) was not found to be significantly predictive of new-onset fractures in the multivariable analysis (p=0.081). CONCLUSION Here we demonstrate the novel, MRI-derived VBQ score is both an independent predictor of fragility fracture in at-risk patients and a superior predictor of fracture risk than DXA-measured BMD. Given the frequency with which MRIs are obtained by patients undergoing spine surgery consultation, we believe the VBQ score could be a valuable tool for estimating bone quality in order to optimize the management of these patients. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Current evidence suggests that dual energy X-ray absorptiometry (DXA) scans –conventional method defining osteoporosis – is underutilized and, when used, may underestimate patient risk for skeletal fragility. It has recently been suggested that other imaging modalities may better estimate bone quality, such as the MRI-based vertebral bone quality (VBQ) score, previously associated with vertebral compression fracture risk in patients with spine metastases. To evaluate whether VBQ score is predictive of fragility fractures in a population with pre-existing low bone density and at high-risk for fracture. Retrospective single-center cohort. Patients followed at a metabolic bone clinic for osteopenia/osteoporosis. Radiographically-documented new- onset fragility fracture. Patients with a DXA and MRI scans at the time of consultation and ≥2-year follow-up were included. Details were gathered about patient demographics, health history, current medication use, and serological studies of kidney function and bone turnover. For each patient, VBQ score was calculated using T1-weighted lumbar MRI images. Univariable and multivariable analyses were used to identify the independent predictors of a new fragility fracture. To support the construct validity of VBQ, patient VBQ scores were compared to those in a cohort of 45 healthy adults. Seventy-two (39.1%) study participants suffered fragility fractures, the occurrence of which was associated with higher VBQ score (3.50 vs 3.01; p<0.001), chronic glucocorticoid use (30.6% vs 15.2%; p=0.014), and a history of prior fragility fracture (36.1% vs 21.4%; p=0.030). Mean VBQ score across all patients in the study cohort was significantly higher than the mean VBQ score in the healthy controls (p<0.001). In multivariable analysis, new-onset fracture was independently associated with history of prior fracture (OR=6.94; 95% CI [2.48–19.40]; p<0.001), higher VBQ score (OR=2.40 per point; [1.30–4.44]; p=0.003), higher BMI (OR=1.09 per kg/m 2 ; [1.01–1.17]; p- 0.03), and chronic glucocorticoid use (OR=2.89; [1.03–8.17]; p=0.043). Notably, DXA bone mineral density (BMD) was not found to be significantly predictive of new-onset fractures in the multivariable analysis (p=0.081). Here we demonstrate the novel, MRI-derived VBQ score is both an independent predictor of fragility fracture in at-risk patients and a superior predictor of fracture risk than DXA-measured BMD. Given the frequency with which MRIs are obtained by patients undergoing spine surgery consultation, we believe the VBQ score could be a valuable tool for estimating bone quality in order to optimize the management of these patients.

Dual-energy X-ray absorptiometry bone densitometry in pediatrics: a practical review and update.

The assessment of pediatric bone mineral content and density is an evolving field. In this manuscript we provide a practical review and update on the interpretation of dual-energy X-ray absorptiometry (DXA) in pediatrics including historical perspectives as well as a discussion of the recently published 2019 Official Position Statements of the International Society of Clinical Densitometry (ISCD) that apply to children.

Development Of A Dxa-derived Body Volume Equation In Hispanic Adults For Administering In 4-compartment Models

PURPOSE: The purpose of the current study was two-fold: 1) to develop a new dual energy X-ray absorptiometry (DXA)-derived body volume (BV) equation with the GE-Lunar Prodigy while utilizing underwater weighing (UWW) as a criterion and 2) cross-validate 4-compartment(4C) models when utilizing the new DXA-derived BV equation (4C-DXANICKERSON), Wilson DXA-derived BV equation (4C-DXAWILSON), and air displacement plethysmography (ADP)-derived BV (4C-ADP) in Hispanic adults. METHODS: 191 Hispanic adults (18-45yrs) participated in the current study. The development sample consisted of 60 females and 60 males whereas the cross-validation sample comprised of 41 females and 30 males. Criterion body fat percentage (BF%) and fat-free mass (FFM) were determined using a 4C model with UWW as a criterion for BV (4C-UWW). The new DXA-derived BV equation (Nickerson) was developed by linearly regressing UWW-derived BV with DXA fat mass (FM), lean mass (LM), and bone mineral content (BMC). 4C-DXANICKERSON, 4C-DXAWILSON, and 4C-ADP were compared against 4C-UWW in the cross-validation sample. RESULTS: The new DXA-derived BV equation (L) was generated in the development sample as follows: (FM/0.91) + (LM/1.06) + (BMC/16.95) + 0.268. 4C-DXANICKERSON, 4C-DXAWILSON, and 4C-ADP all produced similar mean values (BF%=21.04±5.99, 22.23±6.93, and 20.62±6.26%, respectively) when compared to 4C-UWW (21.29±6.14%) in Hispanic males (all p>0.05). 4C-DXANICKERSON also yielded similar BF% and FFM values as 4C-UWW when evaluating the constant error (CE) in Hispanic females (CE=-0.79% and 0.38kg; p=0.060 and 0.174, respectively). However, 4C-DXAWILSON produced significantly different BF% and FFM values (CE=3.22% and -2.20kg, respectively; both p<0.001). Additionally, 4C-DXAWILSON yielded significant proportional bias when estimating BF% (coefficient=0.226; p<0.001) whereas 4C-ADP produced significant proportional bias for BF% and FFM (coefficient=0.188 and -0.084; both p<0.05) when evaluated in Hispanic females. CONCLUSIONS: Current study findings demonstrate that 4C-DXANICKERSON is a valid measure of BV in Hispanics and is recommended for use in clinics where DXA is the main body composition assessment technique.

Oral bisphosphonate treatment in patients with Duchenne muscular dystrophy on long term glucocorticoid therapy

Osteoporosis is a major problem in patients with Duchenne muscular dystrophy (DMD), due to glucocorticoid therapy and muscle weakness. Evidence on which to base optimal prevention and treatment strategies, including bisphosphonate use, in DMD are limited. Our objective was to describe bone health outcomes of oral alendronate treatment in patients with DMD and glucocorticoid-induced osteoporosis. We retrospectively studied 54 patients treated between 2005 and 2017, and assessed changes in dual-energy x-ray absorptiometry (DXA) whole body and lumbar spine bone mineral density and content, and lateral distal femur bone mineral density. We also examined vertebral fracture development in a subset with serial spine radiographs. Pre-alendronate DXA Z-score trajectories decreased progressively. Over three years post-alendronate initiation, Z-score trajectories improved (p<0.01) at most sites compared with pre-alendronate trajectories. Height-adjusted Z-score trajectories for lumbar spine bone mineral density (p = 0.01) and whole body bone mineral content (p = 0.0004) also improved. The positive trajectories did not seem to be sustained long term in those treated up to 6 years. Radiographic vertebral findings in 43 patients appeared stable. In conclusion, oral bisphosphonate therapy using alendronate was associated with improvement of DXA bone health indices during the first three years of treatment, and may help mitigate progression of osteoporosis in glucocorticoid-treated patients with DMD.

Vertebral bone quality score predicts fragility fractures independently of bone mineral density

BackgroundCurrent evidence suggests that dual-energy x-ray absorptiometry (DXA) scans, the conventional method defining osteoporosis, is underutilized and, when used, may underestimate patient risk for skeletal fragility. It has recently been suggested that other imaging modalities may better estimate bone quality, such as the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score which also may assess vertebral compression fracture risk in patients with spine metastases. PurposeTo evaluate whether VBQ score is predictive of fragility fractures in a population with pre-existing low bone density and at high-risk for fracture. Study Design/SettingRetrospective single-center cohort. Patient SamplePatients followed at a metabolic bone clinic for osteopenia and/or osteoporosis. Outcome MeasuresRadiographically-documented new-onset fragility fracture. MethodsPatients with a DXA and MRI scans at the time of consultation and ≥2-year follow-up were included. Details were gathered about patient demographics, health history, current medication use, and serological studies of kidney function and bone turnover. For each patient, VBQ score was calculated using T1-weighted lumbar MRI images. Univariable and multivariable analyses were used to identify the independent predictors of a new fragility fracture. To support the construct validity of VBQ, patient VBQ scores were compared to those in a cohort of 45 healthy adults. ResultsSeventy-two (39.1%) study participants suffered fragility fractures, the occurrence of which was associated with higher VBQ score (3.50 vs. 3.01; p<.001), chronic glucocorticoid use (30.6% vs. 15.2%; p=.014), and a history of prior fragility fracture (36.1% vs. 21.4%; p=.030). Mean VBQ score across all patients in the study cohort was significantly higher than the mean VBQ score in the healthy controls (p<.001). In multivariable analysis, new-onset fracture was independently associated with history of prior fracture (OR=6.94; 95% confidence interval [2.48–19.40]; p<.001), higher VBQ score (OR=2.40 per point; [1.30–4.44]; p=.003), higher body mass index (OR=1.09 per kg/m²; [1.01–1.17]; p=.03), and chronic glucocorticoid use (OR=2.89; [1.03–8.17]; p=0.043). Notably, DXA bone mineral density (BMD) was not found to be significantly predictive of new-onset fractures in the multivariable analysis (p=.081). ConclusionsHere we demonstrate the novel, MRI-derived VBQ score is both an independent predictor of fragility fracture in at-risk patients and a superior predictor of fracture risk than DXA-measured BMD. Given the frequency with which MRIs are obtained by patients undergoing spine surgery consultation, we believe the VBQ score could be a valuable tool for estimating bone quality in order to optimize the management of these patients.

Nevirapine Use Is Associated with Higher Bone Mineral Density in HIV-1 Positive Subjects on Long-Term Antiretroviral Therapy.

We assessed bone mineral density (BMD) in a cohort of human immunodeficiency virus (HIV)-positive patients after a median of 11 years of combination antiretroviral therapy (cART) and evaluated the respective role of HIV infection and antiretroviral drugs (ARVs). A cross-sectional study of 162 participants (131 male) from the ANRS-C08 cohort was performed with bone dual-energy X-ray absorptiometry (DXA) scans and renal assessment. The window of exposure to ARVs was defined as an exposure of more than six cumulative months during the last 3 years before the DXA evaluation to account for a cumulative exposure that could affect bone remodeling. The association with low BMD (Z-score < -2) was assessed by a multiple logistic regression model. The study population was 50 years (median), hepatitis C virus (HCV) (18%), and hepatitis B virus (HBV) (8%) coinfection with HIV-RNA <50 c/mL in 89%, median CD4 of 619/mm3. Prevalence of low BMD was 18% in males and 6% in females. The factors associated with a Z-score < -2 in males were uric acid renal loss [adjusted odds ratio (aOR): 6.1; 95% confidence interval (CI): 1.2-31.5; p = .03], HCV coinfection (aOR: 4.0; 95% CI: 1.3-12.2; p = .02), and less frequent window of exposure to nevirapine (NVP) (aOR: 0.1; 95% CI: 0.02-0.6; p = .01). For the full study sample, there was a strong positive association between duration of exposure to NVP and lumbar spine Z-score (p = .004). HIV-positive patients exposed to long-term cART have a high incidence of low BMD. Tenofovir disoproxil fumarate and ritonavir-boosted protease inhibitors did not seem to be associated with increased risk of low BMD, whereas NVP exposure appeared to have an independent positive association.

Dietary Calcium to Digestible Phosphorus Ratio for Optimal Growth Performance and Bone Mineralization in Growing and Finishing Pigs.

Simple SummaryMinimizing the use of dietary non-renewable mineral phosphates improves the sustainability of phosphorus use in growing-finishing pigs. As the phosphorus metabolism is closely linked to calcium, this experiment compared three dietary calcium to digestible phosphorus ratios within two phosphorus levels to determine the optimum levels for growth performance and bone mineralization. The lowest calcium level was insufficient for an efficient metabolic use of P, the medium level was sufficient to maximize growth performance and highest level further improved bone mineralization. The low digestible phosphorus level enabled a complete removal of supplemented mineral phosphates in the finisher period, which resulted, per pig, in a decrease of its use by 65% and a decrease of the calculated P excretion by 41%, without impaired growth performance. However, a reduced bone mineralization was observed. This study shows that there is potential to reduce the digestible phosphorus compared to practiced levels in grower–finisher pigs and shows that the optimal calcium to digestible phosphorus ratio needs to be maintained at the upper range of the actually available recommendations.Within the context of maximizing the use of dietary phosphorus, a growing-finishing pig study was conducted to determine the optimal total dietary calcium (Ca) to digestible phosphorus (dP) ratio and to verify the possibility of mineral phosphate removal during the finishing period on growth performance and mineral status. The potential for replacing chemical and mechanical bone properties by dual energy X-ray absorptiometry (DXA) measures on non-dissected feet was also verified. Three Ca to dP ratios (2.2:1, 2.5:1 and 2.8:1) within two dP levels (P+, P–) were fed during 91 days to 84 pigs. The grower and finisher P+ diets contained 3.0 and 2.4 and P– diets contained 2.5 and 1.7 g dP/kg, respectively. Growth performance and blood serum mineral content were independent of treatments, except that 2.2:1 impaired finisher feed conversion ratio compared to 2.5:1 and 2.8:1. Urinary P concentration increased by 37% in 2.2:1 compared to 2.5:1 and 2.8:1. Maximal load on bone and DXA mineral density were reduced in 2.2:1 compared to 2.8:1. Bone ash and volumetric density were reduced in 2.2:1 and 2.5:1 compared to 2.8:1. Diet P– reduced bone ash, maximal load, volumetric density and DXA bone mineral content and density. No interaction was observed between Ca and dP level. Therefore, 2.2:1 was insufficient for an efficient metabolic use of P, 2.5:1 was sufficient to maximize growth performance and 2.8:1 further improved bone mineralization. Increasing dietary Ca did not impair bone zinc content. Diets P– without supplemented mineral phosphates during the finisher period resulted, per pig, in a decrease of its use by 65% and of the calculated P excretion by 41%, without impaired growth performance. Finally, DXA data responded to dietary treatments as did labor intensive chemical and mechanical bone properties.

Hypoperfusion in the posterior cingulate cortex is associated with lower bone mass density in elderly women with osteopenia and Alzheimer's disease.

Accelerated bone loss is closely associated with Alzheimer's disease (AD), but the relationship between bone mineral density (BMD) and imaging markers of neurodegeneration remains uncertain. We examined the effect of low bone mass (osteopenia) on regional cerebral blood flow (rCBF) in patients with AD (n=19) and non-demented aging (n=12). We enrolled 31 female outpatients diagnosed with osteopenia (age≥65years) who had both a single-photon emission computed tomography brain scan and dual-energy X-ray absorptiometry bone scan taken at their initial investigation. We analyzed the relationship between osteopenia (-2.5<T-score<-1) and rCBF in 62 cortical areas measured using the stereotactic extraction estimation analysis on single-photon emission computed tomography (SPECT) (mean Z-scores). We found that the mean Z-scores of 14 cerebral subregions, most of which are often affected early in AD, were significantly lower in the AD group than the non-demented group (P<.001). The age-stratified multivariate regression analysis showed that the decreased rCBF in the left posterior cingulate cortex (PCC) was an independent predictor of osteopenia (r=-0.395; P=.005). BMD and rCBF in the left PCC were significantly correlated in the overall population (r=-0.54; P=.001), as well as the AD group (r=-0.514; P=.02). These imaging data suggest that osteopenia may contribute to neurodegeneration of a brain network hub associated with AD.

Dual Energy X-ray Absorptiometry Scanning and Bone Health: The Pressing Need to Raise Awareness Amongst Pakistani Women.

IntroductionThe use of dual-energy x-ray absorptiometry (DEXA) scanning is instrumental in better management of osteoporosis. This study aimed to assess the level of knowledge about DEXA scanning and bone health in the women of Karachi, as well as to analyze their practices concerning the scan and increase their knowledge and awareness regarding the same.Methodology The sample size for this cross-sectional study was 384. Data were collected using a self-devised and validated questionnaire, consisting of four sections: social demographics, general knowledge about DEXA scanning, practices regarding DEXA, and knowledge about bone health. The data were analyzed using Statistical Package for the Social Sciences (SPSS) version 23 and associations between multiple variables calculated, using independent sample t-test and Pearson’s chi-squared test.ResultsOnly one-third of our sample population had heard about DEXA scanning and amongst them, nobody had complete knowledge about it. The mean score of general knowledge of DEXA (5.3±2.0) was higher than that of knowledge about the conditions in which DEXA scanning is recommended (2.7±2.1). The knowledge score showed a significant correlation with education (p=0.007) and employment (p=0.001). Only 7.6% of the sample population had taken a DEXA scan and knowledge and employment status were found to have significant associations with practices (p value=0.000 and 0.001, respectively).ConclusionsThe awareness levels regarding DEXA scans and bone health should be evaluated amongst similar and other groups of people and effective measures be put into application to educate the public and to guide them towards better prevention and management of osteoporosis.

Characteristics of older adults using patient web portals to view their DXA results

BackgroundSharing test results with patients via patient web portals is a new trend in healthcare. No research has been done examining patient web portal use with bone density test results. The objective of our study was to identify patient characteristics associated with the use of patient web portals to view their bone density test results.MethodsA secondary analysis of data from a pragmatic randomized controlled trial of 7749 participants ≥50 years old that had presented for a dual energy X-ray absorptiometry (DXA) bone density test. Patients were interviewed at enrollment and 12 weeks later. Multivariable logistic regression identified patient characteristics that differentiated those who used the web portal from those who did not.ResultsOur sample included 4669 patients at the two (University of Iowa [UI], and Kaiser Permanente of Georgia [KPGA]) clinical sites that had patient web portals. Of these patients, 3399 (72.8%) reported knowing their test results 12 weeks post-DXA, with 649 (13.9%) reporting that they viewed their DXA results using the web portal. Web portal users were more likely to be from UI than KPGA, and were younger, more educated, had higher health literacy, had osteopenia, and had the same sex as their referring physician (all p < 0.05).ConclusionOnly 19.1% of the 3399 patients who knew their DXA results used the available patient web portals to find out about them. Web portal users differed from non-users on several characteristics. This suggests that simply making patient web portals available for use may not be sufficient to appreciably enhance patient awareness of their test results. Based on these findings, a better understanding of the reasons why older, less educated, and less activated patients do not access their test results through patient web portals is needed.

Measurement and Interpretation of Dual-Energy X-ray Absorptiometry Bone Density Measurements

Dual-energy X-ray absorptiometry (DXA) is a widely used technology used to diagnosis osteoporosis and monitor changes in bone mineral density (BMD). The present paper reviews the clinical application of DXA in evaluating osteoporosis, including indications for BMD testing, interpretation of DXA results, diagnosis of osteoporosis, and serial BMD follow up. As the clinical utility of DXA depends on the quality of the scan acquisition, the precision assessment of DXA is also discussed. Keywords: Osteoporosis; Diagnosis; Bone mineral density; Dual-energy X-ray absorptiometry 중심 단어: 골다공증; 진단; 골밀도; 이중에너지 ì—‘ìŠ¤ì„ í¡ìˆ˜ê³„ì¸¡ë²•

GWAS of bone size yields twelve loci that also affect height, BMD, osteoarthritis or fractures

Bone area is one measure of bone size that is easily derived from dual-energy X-ray absorptiometry (DXA) scans. In a GWA study of DXA bone area of the hip and lumbar spine (N ≥ 28,954), we find thirteen independent association signals at twelve loci that replicate in samples of European and East Asian descent (N = 13,608 – 21,277). Eight DXA area loci associate with osteoarthritis, including rs143384 in GDF5 and a missense variant in COL11A1 (rs3753841). The strongest DXA area association is with rs11614913[T] in the microRNA MIR196A2 gene that associates with lumbar spine area (P = 2.3 × 10−42, β = −0.090) and confers risk of hip fracture (P = 1.0 × 10−8, OR = 1.11). We demonstrate that the risk allele is less efficient in repressing miR-196a-5p target genes. We also show that the DXA area measure contributes to the risk of hip fracture independent of bone density.

The influence of CT and dual-energy X-ray absorptiometry (DXA) bone density on quantitative [18F] sodium fluoride PET.

[18F] sodium fluoride PET/CT provides quantitative measures of bone metabolic activity expressed by the parameters standardised uptake value (SUV) and bone plasma clearance (K i) that correlate with measurements of bone formation rate obtained by bone biopsy with double tetracycline labelling. Both SUV and K i relate to the tracer uptake in each millilitre of tissue. In general, the bone region of interest (ROI) includes both mineralised bone {generally with a high concentration of [18F]NaF} and bone marrow (with a much lower concentration), suggesting that correcting SUV and K i for volumetric bone mineral density (vBMD) and measuring them with respect to the tracer uptake in each gram of bone mineral might improve the correlation with the findings of bone biopsy. As a first test of this hypothesis, we looked for positive correlations between SUV and K i values with CT and DXA bone mineral density (BMD) parameters measured in the same ROI. A retrospective reanalysis was performed of 63 lumbar spine [18F]NaF PET/CT scans acquired in four earlier studies. The quantitative PET parameters SUV and K i were measured in L1-L4 and Hounsfield units (HU) measured on the CT scans in the same ROI. Spine BMD data was also obtained from DXA scans in the form of areal BMD and used to derive the bone mineral apparent density (BMAD, an estimate of vBMD). Scatter plots were drawn of SUV and K i against HU, BMAD and areal BMD and the Spearman rank correlation coefficients derived for each plot. All correlations were positive and statistically significant. Correlations were highest for HU (SUV: RS =0.513, P<0.0001; K i: RS =0.429, P=0.0005) and lowest for areal BMD (SUV: RS =0.353, P=0.005; K i: RS =0.274, P=0.03). The results demonstrate significant positive correlations between SUV and K i and vBMD measurements in the form of HU from CT or BMAD and areal BMD from DXA. These findings justify further exploration of the relationship between SUV and K i [18F]NaF PET/CT measurements and CT or DXA measurements of vBMD to examine whether normalization for bone density might improve their correlation with bone metabolic activity as measured by bone biopsy.

Relationship of cardiometabolic risk biomarkers with DXA and pQCT bone health outcomes in young girls.

Excess weight exerts the positive effect of mechanical loading on bone during development whereas obesity-related metabolic dysfunction may have a detrimental impact. In adults, the presence of metabolic syndrome and type 2 diabetes has been associated with compromised bone density, quality, and strength, and an increased incidence of fractures. The few studies that have investigated the role of cardio-metabolic disease risk biomarkers (CMR) on bone strength in children have given conflicting results. The aim of this study was to assess the combined and independent relationships of cardio-metabolic biomarkers with total body and regional bone parameters in young girls. In 306, 9-12 year old girls, measures of whole body fat and lean mass, areal bone mineral density (aBMD), bone mineral content (BMC), and bone area (BA) were obtained by dual-energy x-ray absorptiometry (DXA). Bone mineral density (vBMD), geometry, and strength of metaphyseal and diaphyseal regions of the femur and tibia and a diaphyseal region of the radius were measured using peripheral quantitative computed tomography (pQCT). Fasting serum measures of CMRs included, fasting glucose, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), high-density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglyceride (TG), systolic and diastolic blood pressure (SBP and DBP), and C-reactive protein (CRP). Multiple linear regression was used to assess the independent associations of a single CMR with total body and peripheral measures of bone strength after controlling for the other CMRs, plus total body soft tissue, and other relevant covariates. Also, a standardized total CMR composite score, calculated by standardizing to z-scores and then summing z-scores of each CMR biomarker, was regressed with total body and regional bone measures to assess the relationship of a cluster of risk factors with bone health. Total CMR composite score had inverse associations (p < 0.001) with DXA total BMC and BA. Inverse associations (p < 0.05) of CMR risk score with pQCT regional bone measures occurred with total and trabecular BA at the 4% tibia. Of the individual CMRs, HOMA-IR and CRP were significant predictors of total body bone measures by DXA accounting for ~1-5% of the variance in BMC, BA, and/or aBMD. HOMA-IR was the main predictor of regional pQCT bone outcomes, accounting for the most variance in trabecular vBMD (2.6%) and BSI (3.8%) at the 4% tibia. Most markers of dyslipidemia (TG, HDL-C, LDL-C) and hypertension (SBP, DBP) were not associated (p > 0.05) with any total body or regional bone outcomes with the exception of the inverse relationship of LDL-C with total and trabecular BA and the positive relationship of DBP with cortical vBMD at the radius. Of the obesity-related metabolic impairments, insulin resistance and chronic inflammation may compromise whole body bone development in young girls. In particular, trabecular bone, such as that found at the metaphysis of long bones, may be more susceptible to the detrimental effects associated with obesity-related metabolic dysfunction.

Improving Bone Mineral Density Assessment Using Spectral Detector CT

Introduction: Bone mineral density (BMD) analysis by Dual-Energy x-ray Absorptiometry (DXA) can have some false negatives due to overlapping structures in the projections. Spectral Detector CT (SDCT) can overcome these limitations by providing volumetric information. We investigated its performance for BMD assessment and compared it to DXA and phantomless volumetric bone mineral density (PLvBMD), the latter known to systematically underestimate BMD. DXA is the current standard for BMD assessment, while PLvBMD is an established alternative for opportunistic BMD analysis using CT. Similarly to PLvBMD, spectral data could allow BMD screening opportunistically, without additional phantom calibration. Methodology: Ten concentrations of dipotassium phosphate (K2HPO4) ranging from 0 to 600 mg/ml, in an acrylic phantom were scanned using SDCT in four different, clinically-relevant scan conditions. Images were processed to estimate the K2HPO4 concentrations. A model representing a human lumbar spine (European Spine Phantom) was scanned and used for calibration via linear regression analysis. After calibration, our method was retrospectively applied to abdominal SDCT scans of 20 patients for BMD assessment, who also had PLvBMD and DXA. Performance of PLvBMD, DXA and our SDCT method were compared by sensitivity, specificity, negative predictive value and positive predictive value for decreased BMD. Results: There was excellent correlation (R2 >0.99, p < 0.01) between true and measured K2HPO4 concentrations for all scan conditions. Overall mean measurement error ranged from −11.5 ± 4.7 mg/ml (−2.8 ± 6.0%) to −12.3 ± 6.3 mg/ml (−4.8 ± 3.0%) depending on scan conditions. Using DXA as a reference standard, sensitivity/specificity for detecting decreased BMD in the scanned patients were 100%/73% using SDCT, 100%/40% using PLvBMD provided T-scores, and 90–100%/40–53% using PLvBMD hydroxyapatite density classifications, respectively. Conclusions: Our results show excellent sensitivity and high specificity of SDCT for detecting decreased BMD, demonstrating clinical feasibility. Further validation in prospective clinical trials will be required.

Comparison of three plain radiography methods for evaluating proximal humerus bone strength in women

BackgroundWe assessed the correlation between three methods for measuring cortical thickness of the humerus on a plain radiograph and bone mineral density measured by dual-energy X-ray absorptiometry in order to establish a simple bone strength evaluation method in patients at risk of proximal humerus fragility fracture. MethodsIn this retrospective study, 1732 patients underwent screening of the distal third radius, proximal femur, and lumbar spine by dual-energy X-ray absorptiometry. We identified 224 patients who also underwent anteroposterior shoulder radiography. Patients with fractures or who had undergone surgery in the region of interest were excluded. The study consisted of 80 women with a mean age of 76 years (range: 39–94 years). Cortical thickness, cortical index, and deltoid tuberosity index were determined to assess the proximal humerus. Correlation between bone mineral density measured by dual-energy X-ray absorptiometry and cortical thickness determined using these three methods was examined. We defined the osteoporosis group as patients satisfying both the World Health Organization criteria and the diagnostic criteria for primary osteoporosis (2012 revision) and compared values between the osteoporotic and non-osteoporotic groups. ResultsBMD correlated positively with cortical thickness, cortical index, and deltoid tuberosity index values, but the strength of correlation differed. These values were significantly lower in the osteoporotic group than in the non-osteoporotic group. Receiver operating characteristic curve analysis revealed that only the distal third radius had an area under the curve of 0.7 or more for all methods. ConclusionsAll three methods yielded values that correlated with the dual-energy X-ray absorptiometry bone mineral density measured at the distal third radius, the proximal femur, and the lumbar spine. The correlation coefficient in the radius was high and differed significantly from those of weight-bearing bones (proximal femur, lumbar spine).

Assessment of Bone and Muscle Measurements by Peripheral Quantitative Computed Tomography in Geriatric Patients

The loss of bone and muscle mass increases the risk of osteoporotic fractures. Dual energy X-ray absorptiometry (DXA) loses sensitivity in older age. The purpose of this study was to evaluate bone and muscle measurements of peripheral quantitative computed tomography (pQCT) in a geriatric cohort with osteoporosis. Bone mineral density and muscle area of 168 patients aged 65 years and older (76.3 ± 6.5) were measured with pQCT at distal forearm additionally to an osteoporosis assessment consisting of anamnesis, blood test and DXA of lumbar spine and hip. Prior fractures were categorized in minor and major osteoporotic fractures. Logistic regression was used to show the association of bone mineral density and muscle area with major fractures. 54.8% of the participants had at least one major fracture. Bone mineral density measured with pQCT and muscle area were significantly associated with these fractures (total and trabecular bone mineral density OR 2.243 and 2.195, p < 0.01; muscle area OR 2.378, p < 0.05), whereas DXA bone mineral density showed no significant association. These associations remained after adjustment for age, sex, BMI, physical activity and other factors. In all models for patients >75 years only muscle area was significantly associated (OR 5.354, p < 0.05) with major fractures. Measurement of bone mineral density and muscle area with pQCT seems to have advantage over DXA in fracture association in geriatric patients. Measuring muscle area also adds useful information to estimate the presence of osteosarcopenia.

Low energy availability assessed by a sport-specific questionnaire and clinical interview indicative of bone health, endocrine profile and cycling performance in competitive male cyclists

ObjectivesTo evaluate the efficacy of a sport-specific energy availability (EA) questionnaire, combined with clinical interview, for identifying male athletes at risk of developing bone health, endocrine and performance consequences of...

Reasonable adjustments to provide equitable and inclusive assessment, screening and treatment of osteoporosis for adults with intellectual disabilities: A feasibility study.

People with intellectual disabilities are a high risk population for developing osteoporosis and fragility fractures, yet they experience barriers to accessing dual-energy x-ray absorptiometry (DXA) bone mineral density (BMD) screening and fracture assessment. Reasonable adjustments are a statutory requirement in the UK, but there is a paucity of evidence-based examples to assist their identification, implementation and evaluation. Thirty adults with intellectual disabilities underwent DXA BMD screening and fracture risk assessment. Reasonable adjustments were identified and implemented. The presence of osteopenia or osteoporosis was detected in 23 out of 29 (79%) participants. Osteoporosis professionals report that 17 of 18 reasonable adjustments identified and implemented are both important and easy to implement. Adults across all levels of intellectual disabilities can complete DXA BMD screening with reasonable adjustments. Widely implementing these reasonable adjustments would contribute to reducing inequalities in health care for adults with intellectual disabilities.