Dual-energy X-ray Absorptiometry T-scores Research Articles

Diagnosis of low bone mass in CKD-5D patients.

Background and objectives: Currently, there is no consensus whether dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography (QCT) can be used to screen for osteoporosis or osteopenia in CKD-5D patients. This study uses iliac bone histology, the “gold standard” for bone volume evaluation, to determine the utility of DXA and QCT for low bone mass screening in CKD-5D patients. Patients and methods: A cross-sectional study of patients with CKD-5D employing iliac crest bone biopsies to assess bone volume by histology and comparing results to bone mineral density (BMD) measurements of the hip and spine by DXA and QCT. Pearson’s correlation, linear regression, and receiver operating characteristics curve analyses were performed. Results: 46 patients (mean age 51 years, 52% women, median dialysis vintage 46 months) had bone biopsies, DXA, and QCT scans. 37 patients (80%) had low bone volume by histology. DXA and QCT BMD values (g/cm2) were very highly correlated at the femoral neck (ρ = 0.97) and total hip (ρ = 0.97), and to a lesser degree at the spine (ρ = 0.65). DXA and QCT t-scores were also highly correlated, but QCT t-scores were systematically greater than DXA t-scores (1.1 S.D. on average at the femoral neck) leading to less recognition of osteopenia and osteoporosis by QCT. A t-score below –1 by DXA at the femoral neck (i.e., osteopenic or osteoporotic) showed 83% sensitivity and 78% specificity relative to low bone volume by histology. A QCT t-score below –1 did not reach acceptable diagnostic levels of sensitivity and specificity. Conclusions: DXA and QCT provide nearly identical areal BMD measures at the hip. However, QCT t-scores are consistently higher than DXA t-scores resulting in less diagnosis of osteoporosis or osteopenia. DXA results showed acceptable diagnostic sensitivity and specificity for low bone volume by histology and can be used for diagnosis of osteopenia and osteoporosis in patients with CKD-5D.

Lumbar Bone Mineral Density Phantomless Computed Tomography Measurements and Correlation with Age and Fracture Incidence

Objective: Low bone quality is a contributing factor to motor vehicle crash (MVC) injury. Quantification of occupant bone mineral density (BMD) is important from an injury causation standpoint. The first aim of this study was to validate a technique for measuring lumbar volumetric BMD (vBMD) from phantomless computed tomography (CT) scans. The second aim was to apply the validated phantomless technique to quantify lumbar vBMD in Crash Injury Research and Engineering Network (CIREN) occupants for correlation with age, fracture incidence, and osteopenia/osteoporosis diagnoses.Methods: Quantitative CT (qCT) and dual-energy X-ray absorptiometry (DXA) were collected prospectively for 50 subjects and used to validate a technique to measure vBMD from 281 phantomless CT scans of CIREN occupants. Hounsfield unit (HU) measurements were collected from the L1–L5 vertebrae, right psoas major muscle, and anterior subcutaneous fat for all subjects and from 3 phantom ports with known mg/cc calcium hydroxyapatite values for the validation group. qCT calibration was accomplished using regressions between the phantom HU and mg/cc values to convert L1–L5 HU values to mg/cc. A phantomless calibration technique was developed where the fat and muscle HU values were linearly regressed against fat (−69 mg/cc) and muscle (77 mg/cc) to establish a conversion for L1–L5 HU measurements to mg/cc. vBMD calculated from qCT versus the phantomless method was compared for the 50 subjects to assess agreement and a mg/cc osteopenia threshold was established using DXA T-scores. CIREN HU measurements were converted to mg/cc using the phantomless technique and the mg/cc osteopenia threshold was used to compare vBMD to age, fracture incidence, and osteopenia comorbidity classifications in CIREN.Results: Linear regression of lumbar vBMD derived from the qCT versus phantomless calibrations showed excellent agreement (R2 = 0.87, P <.0001). A 145 mg/cc threshold for osteopenia was established (sensitivity = 1, specificity = 0.57) and 44 CIREN occupants had vBMD below this threshold. Of these 44 occupants, 64% were not classified as osteopenic in CIREN, but vBMD suggested undiagnosed osteopenia. Age was negatively correlated with vBMD in both sexes (P <.0001) and CIREN occupants with less than 145 mg/cc vBMD sustained an average 1.7 additional rib/sternum fractures (P =.036).Conclusions: Because lumbar vBMD was estimated from phantomless CT scans with accuracy similar to qCT, the phantomless technique can be broadly applied to both prospectively and retrospectively assess patient bone quality for research and clinical studies related to MVCs, falls, and aging.

Use of routine thoracic and abdominal computed tomography scans for assessing bone mineral density and detecting osteoporosis

Objective:Evaluation of computed tomography (CT) attenuation measurements for assessing bone mineral density (BMD) and predicting osteoporosis in thoracic and abdominal CT scans for various clinical indications using dual-energy X-ray absorptiometry (DXA) as reference standard.Research design and methods:A total of 234 patients (147 women, 87 men) undergoing DXA and CT were examined retrospectively. Mean time between both studies was 0.5 years. CT-attenuation values in Hounsfield units (HU) were measured at the thoracic and lumbar spine (T1, T6, T12, L1–L5), at the femoral neck, and then assigned to their corresponding DXA scores.Results:Patients with DXA-defined osteoporosis or osteopenia showed significantly lower HU values of trabecular bone at all measured levels compared to healthy subjects (p < 0.001). HU values were highest at T1 and T6, lowest at L1–L3 and the femoral neck. There were no significant intraindividual differences between HU values in the sagittal, coronal or transversal plane. Significant differences between normal and abnormal BMD categories were verified for three CT scanners. More than half of all fractures were detected in patients with non-osteoporotic DXA T-scores.Conclusions:Abdominal and particularly thoracic CT scans obtained for other clinical indications can sensibly be applied toward determining low BMD, detecting osteoporosis and identifying persons at increased fracture risk. Osteoporotic morbidity and mortality might be minimized. Superiorly to DXA, fragility fractures can be found without additional imaging or radiation exposure which can initiate early adequate treatment.Limitations:Key limitations of the study were as following: a retrospective, single-center study; small patient cohort – larger cohorts are needed to evaluate the sensitivity and specificity of diagnostic performance measurements; more complex CT evaluation of the hip for BMD assessment; DXA measurements were used as a reference standard, however, patients with unsuspected compression fractures but showing osteopenic or even normal BMD outline the limitations of DXA.

Abstract P1-09-33: Weight loss and bone health in postmenopausal breast cancer survivors

Abstract Background: The importance of bone health among postmenopausal breast cancer survivors cannot be overemphasized. In addition to bone loss due to aging, secondary bone loss resulting from treatment is a major concern. Although weight loss has adverse effects on bone health in postmenopausal women without cancer, the impact of weight loss on bone health in postmenopausal women with breast cancer is not known. Our objective in this study was to evaluate the effect of weight loss on bone health among overweight/obese postmenopausal breast cancer survivors participating in a weight loss trial. Methods: We conducted this study in a subset of women (postmenopausal, N=81) enrolled in the multi-site Exercise and Nutrition to Enhance Recovery and Good health for You (ENERGY) study. The ENERGY study is a randomized controlled clinical trial designed to achieve a sustained ≥7% loss in body weight among overweight/obese breast cancer survivors with stage I, II or IIIA disease. Weight loss was achieved largely through dietary modification with the addition of physical activity. Bone health was assessed in a subset of women at a single site using bone turnover markers (BTMs) and dual energy X-ray absorptiometry (DXA). Markers of bone formation: osteocalcin, bone-specific alkaline phosphatase (BALP), procollagen type I N-terminal propeptide (PINP) and bone resorption: N-telopeptides of type-I collagen (NTX), C-terminal telopeptide (CTX) were quantified in blood samples collected at baseline, 6 month and 12-month follow-up. DXA T-score was used to measure bone mineral density at baseline and at 12-month follow-up. Generalized estimating equations were used to assess differences in mean values over time as well as from baseline to 6- and 12-month follow-up. Data from intervention and control arm women were used and treated as a cohort. Results: The mean age and body mass index (BMI) of women enrolled in our sub-study were 56 years and 31.6kg/m2, respectively. Majority (54.3%) had stage 2 disease. Mean weight decreased by 5.6 pounds between baseline and 6-month follow-up and 4.3 pounds between baseline and 12-month follow-up. There were statistically significant decreases in mean osteocalcin (2.0ng/ml, p-value&amp;lt;0.001), PINP (7.9ng/ml, p-value&amp;lt;0.001) and NTx (3.65nM BCE/L, p-value&amp;lt;0.001), but not BALP and CTX-1 levels between baseline and 12-month follow-up. No significant changes were observed in mean T-scores, pelvis and lumbar spine bone mineral densities between baseline and 12-month follow-up. Weight change from baseline to 12-month follow-up was weakly inversely associated with changes in DXA T-score (r=-0.25, p-value=0.04) and CTX (r=-0.22, p-value=0.07) but not with other BTMs over the same time period. Conclusion: Weight loss over a 12-month period was associated with decreases in markers of bone formation and resorption but no changes in BMD in overweight/obese postmenopausal women with stage I, II or IIIA breast cancer. Further studies on the association of weight loss and the possible modifying effect of physical activity are needed in order to personalize weight control strategies in overweight/obese breast cancer survivors. Citation Format: Adetunji T Toriola, Jingxia Liu, Patricia A Ganz, Graham A Colditz, Lin Yang, Sonya Izadi, Anna L Schwartz, Kathleen Y Wolin. Weight loss and bone health in postmenopausal breast cancer survivors [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-09-33.

Fracture Prevalence in Adults with Transfusion-Dependent Thalassemia Is Related to Osteoporosis and Age

Introduction: Adults with transfusion dependent thalassemia syndromes are living into later adulthood as a result of better transfusion therapy and chelation. Unfortunately, chronic health problems develop in these patients that persist into adulthood. Osteoporosis and osteopenia are significant co-morbidities in the thalassemia population as a result of impaired growth in childhood, extramedullary expansion of the marrow, iron deposition, vitamin D deficiencies, and hypogonadism. The morbidity of osteoporosis is significant in this population, leading to fractures and chronic pain.The purpose of this study was to provide a cross-sectional descriptive analysis of bone disease in adult thalassemia patients with osteoporosis and fracture histories.Methods: A retrospective review of electronic medical records was carried out from patients with transfusion-dependent thalassemia (>8 transfusions per year) seen at the Weill Cornell Comprehensive Thalassemia Center. Information on demographics, diagnosis, iron assessment, and co-existing medical conditions was collected. Results of dual-energy X-ray absorptiometry (DEXA) scans as well as urine and serum markers of bone turnover were also obtained (C-telopeptide (CTX), N-telopeptide (NTX), bone alkaline phosphatase (AP)). The prevalence of fractures was collected.Results: We identified 65 adult patients with transfusion-dependent thalassemia (median age = 36.8, range 16-56; 41 female, 24 male). Thirteen patients had diagnosed thalassemia intermedia (TI), one patient had hemoglobin Lepore, one patient had alpha-thalassemia major, and one patient had Hemoglobin E/beta thalassemia. The remaining patients (n = 49) had thalassemia major. 98% of patients (n=64) were on chelation therapy, the median liver iron content (LIC) was 2.821 mg/g dw (range 0.5 – 135) with a median T2* on cardiac MRI of 34.5 msec (range 7-49 msec).Based on T score <-2.5, 26/65 (40%) of adults were classified as having osteoporosis. The median DEXA T-score at the lumbar spine was -2.4, and -1.95 at the femoral neck. Median markers of bone turnover were CTX=439 pg/ml, range 48-1030; NTX=61 mg/dl, range 19-566; and AP= 18 ug/L, range 8.9-99. We identified 26 patients with fracture history. Comparing those patients with fractures (n=26) to those without fractures (n=39), the only significant difference was lumbar spine DEXA scores (median T-2.66 in those with fractures vs -1.91 in those without fractures; p=0.023). There was a non-significant trend toward significance in T scores differences in T scores of the hips (median T score -2.25 vs -1.7). There were no significant differences in markers of bone turnover between the two groups. When analyzing age groups in the adult population, there was a non-significant trend of decreased markers of bone turnover in older patients. Fracture history was significantly associated with age (patients <30 had a 20% fracture prevalence, 31-40 had a prevalence of 23.1%, and >41 had a prevalence of 66.7%; p=0.001).Conclusions: Osteoporosis remains a significant problem in the adult transfusion-dependent thalassemia population, and often begins in young adulthood. A fracture history is significantly associated with decreased DEXA T scores. Bone turnover markers decrease with age, which may reflect decreased remodeling or increased use of bone-sparing treatments. A fracture history was far more common in patients over the age of 40. Improved treatments for transfusion-dependent thalassemia patients with osteoporosis should be a high priority for future research. DisclosuresChapin:Novo-Nordisk: Honoraria; Alexion: Honoraria. Kleinert:Apopharma: Membership on an entity’s Board of Directors or advisory committees; Novartis: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau.

Abnormalities in cortical bone, trabecular plates, and stiffness in postmenopausal women treated with glucocorticoids.

The mechanisms by which glucocorticoids (GCs) increase skeletal fragility are not well understood. The objective of the study was to evaluate the microarchitecture, trabecular morphology, and biomechanical properties of bone in postmenopausal women treated with GCs. This was a case-control study. The study was conducted at a university hospital outpatient facility. Postmenopausal women treated with oral GCs for longer than 3 months (n = 30) and age/race-matched controls (n = 60) participated in the study. Areal bone mineral density aBMD (BMD) by dual-energy x-ray absorptiometry (DXA) was measured. Trabecular and cortical volumetric BMD (vBMD) and microarchitecture by high-resolution peripheral computed tomography of the distal radius and tibia were also measured. Whole-bone stiffness was estimated by finite element analysis. A novel technique, individual trabecula segmentation, was used to evaluate trabecular type (as plate or rod), orientation, and connectivity. DXA T-scores did not differ significantly at any site. GC subjects had significantly lower total, cortical, and trabecular vBMD and thinner cortices, fewer, thinner, more widely, and irregularly spaced trabeculae. They had fewer trabecular plates, fewer axially aligned trabeculae, and lower trabecular connectivity. Differences ranged from 4% to 65% for these trabecular measures and 5% to 17% for the cortical measures. Whole-bone stiffness was significantly lower (11%-16%) in GC subjects. Markers of bone formation (osteocalcin and amino-terminal propeptide of type I procollagen) and resorption (C-telopeptide) were lower in the GC subjects. Despite similar areal BMD by DXA, GC-treated women had abnormal cortical and trabecular vBMD and microarchitecture at both the radius and tibia, including fewer trabecular plates, a less axially aligned trabecular network, lower trabecular connectivity, thinner cortices, and lower whole-bone stiffness. Further research into these abnormalities as mechanisms for fracture in GC-treated women is warranted.

Use of DXA-based technology for detection and assessment of risk of vertebral fracture in rheumatology practice.

Measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA) is the recommended method for diagnosis of osteoporosis and assessment of future fracture risk. However, most patients who will suffer fractures do not have osteoporosis by DXA (T-score of -2.5 or less). Bone strength, which is most closely associated with resistance to fracture, is a composite of both bone density and bone quality, and the latter is not measured by DXA. Thus, other technology is needed for non-invasive and inexpensive assessment of bone strength and fracture risk. Vertebral fractures, the most common clinical fracture in the general population, are of even greater importance in rheumatoid arthritis and other rheumatic disorders. Vertebral fracture assessment (VFA) and trabecular bone scores (TBS), two techniques which can aid prediction of future fracture risk, can be used with currently available DXA machines. Description of these techniques and their potential application to clinical rheumatology practice will be the focus of this paper.

Comparison of Femoral Neck BMD Evaluation Obtained Using Lunar DXA and QCT With Asynchronous Calibration From CT Colonography

For patients undergoing screening computed tomography colonography (CTC), an opportunity exists for bone mineral density (BMD) screening without additional radiation exposure using quantitative computed tomography (QCT). This study investigated the use of dual-energy X-ray absorptiometry (DXA)–equivalent QCT Computed Tomography X-Ray Absorptiometry (CTXA) analysis at the hip obtained using CTC examinations using a retrospective asynchronous calibration of patient scans. A cohort of 33 women, age 61.3 (10.6) yr (mean [standard deviation]), had routine CTC using various GE LightSpeed CT scanner models followed after 0–9 mo by a DXA hip BMD examination using a GE Lunar Prodigy machine. Areal bone mineral density (aBMD) and T-scores of the proximal femur were measured from either prone or supine CTC examinations using Mindways QCT Pro software following standard workflow except that the CT scanners were asynchronously calibrated by phantoms scanned retrospectively of the CTC examination without the subject present. CTXA and DXA aBMD were highly correlated (R2 = 0.907) with a linear relationship of DXA_BMD = 1.297*CTXA_BMD + 0.048. The standard error of estimate (SEE) on the linear fit was 0.053 g/cm2. CTXA and DXA T-scores showed a linear relationship of DXA_T-score = 1.034*CTXA_T-score + 0.3 and an SEE of 0.379 T-scores. CTXA and DXA aBMD and T-score measurements showed good correlation despite asynchronous scan acquisition and retrospective QCT calibration. The SEE of 0.053 g/cm2 is on par with the literature comparing Hologic and Lunar DXA devices. The observed relationship between CTXA and Lunar DXA aBMD matches predictions from published cross-calibrations relating CTXA to DXA aBMD measurement. Thus, opportunistic use of CTXA T-scores obtained at the time of CTC could enhance osteoporosis screening.

Individualizing osteoporosis medications

Mrs. JD is a 58-year-old postmenopausal woman having symptoms of hot flashes and night sweats. She has a dual-energy x-ray absorptiometry T-score of -2.4 in the femoral neck, consistent with low bone mass or osteopenia. She has a parental history of hip fracture. FRAX shows the 10-year absolute risk of major osteoporotic fracture equal to 18% and the 10-year risk of hip fracture above 3% at 3.2%, which meets the National Osteoporosis Foundation threshold. Mrs. JD is taking calcium 1,200 mg, between supplement and diet, and 1,000 IU vitamin D3 daily. How should she be treated?

Self-reported exercise and bone mineral density in prostate cancer patients receiving androgen deprivation therapy

Men with prostate cancer receiving androgen deprivation therapy (ADT) are at increased risk for decreased bone mineral density (BMD). This study evaluates the relationship between self-reported daily activity, endurance and resistance exercise, and BMD measured by dual-energy x-ray absorptiometry (DEXA) in prostate cancer patients receiving ADT. We recruited 96 men treated with ADT for ≥9 months from urology and cancer practices. The Canadian Fitness Survey assessed daily activity and exercise. Data on demographic and lifestyle characteristics and calcium and vitamin D supplementation were collected. Blood was collected for analysis of 25-OH vitamin D. A DEXA scan was performed. A positive association between endurance exercise and DEXA T-scores of the hip was shown. Regression analysis showed endurance exercise of medium to heavy intensity (measured as energy expenditure in MET-hours/week) was associated with T-scores of the hip (β = 0.048; 95% CI 0.003, 0.112; p = .040) but not with spinal T-scores after controlling for age, body mass index, and alcohol use. Findings are cross-sectional, but if confirmed in prospective studies suggest that increased endurance exercise is a practical measure nurse practitioners can institute to prevent low bone density in the hip of men treated with ADT.

Dual-energy X-ray absorptiometry versus quantitative ultrasonography in diagnosing osteoporosis in patients with refractory epilepsy and chronic antiepileptic drug use

The aim of this study was to assess the feasibility of calcaneal quantitative ultrasonography (QUS) as a screening method for increased risk of osteoporosis in a unique population of people with chronic epilepsy, intellectual disability (ID), and chronic use of antiepileptic drugs. A total of 205 patients from a long-stay care facility for people with epilepsy underwent dual-energy X-ray absorptiometry (DXA) and QUS of the calcaneus. T-scores for both DXA and QUS were calculated and correlated. A total of 195 patients (95.1%) were successfully measured with DXA and 204 (99.5%) with QUS. High correlations were found between DXA and QUS T-scores: r = 0.666 (QUS versus T-score total femur), r = 0.631 (QUS versus T-score femur neck) and r = 0.485 (QUS versus T-score lumbar spine). All correlations were statistically significant (p = 0.01). QUS showed a strong correlation with DXA and proved to be a feasible measuring method in a population with ID and epilepsy. Including osteopenia in the screening process increases the sensitivity of QUS to identify those patients at risk for the development of bone diseases.

Antiepileptic drugs and high prevalence of low bone mineral density in a group of inpatients with chronic epilepsy

Long-term antiepileptic drug use is associated with low bone mineral density (BMD), fractures and abnormalities in bone metabolism. We aimed at determining the prevalence of bone mineral disorders in patients with refractory epilepsy treated with antiepileptic drugs. A cross-sectional survey was conducted in adult patients (n = 205) from a residential unit of a tertiary epilepsy centre. Screening for bone mineral disorders was performed with dual-energy X-ray absorptiometry (DXA) scan of spine and hip (including bone mineral density and vertebral fracture assessment) and laboratory measurements. Patient information regarding demography, epilepsy characteristics and medication use was recorded. Based on DXA T-scores, prevalence of bone mineral disorders (osteopenia and osteoporosis) was calculated. Correlations between DXA T-scores and epilepsy parameters were explored. Of the 205 patients, there were 10 dropouts. 80% (n = 156/195) of the patients had low BMD: 48.2% had osteopenia and 31.8% had osteoporosis. Of those having low BMD, 51.9% (n = 81/195) was between 18 and 50 years. The T-score of the femoral neck correlated significantly with total duration of epilepsy, cumulative drug load and history of fractures. Linear regression analysis showed that of the epilepsy-related parameters, only cumulative drug load significantly predicted low femoral neck T-score (P = 0.001). In this high-risk population, we obtained a very high prevalence of 80% of low BMD. Both men and women were affected as well as patients <50 years of age. This study illustrates the magnitude of the problem of bone mineral disorders in chronic epilepsy.

Abstract P6-12-03: Effects of high dose of bisphosphonate therapy on bone microarchitecture of the peripheral skeleton in women with early stage breast cancer

Abstract Background: Randomized studies investigating adjuvant bisphosphonates in women with breast cancer are ongoing. While bisphosphonates would be expected to prevent the deterioration of bone microarchitecture that accompanies hormone or chemotherapy, complete suppression of osteoclast activity for prolonged periods of time can decrease repair of micro-cracks, and possibly lead to decreased bone strength. While bone strength is governed by the amount of bone present, trabecular and cortical components of bone microarchitecture also contribute independently to bone strength. We aimed to characterize the effects of long-term bisphosphonates on bone microarchitecture in women with breast cancer using high-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius and tibia. Methods: We conducted a cross-sectional study involving early stage breast cancer patients treated with bisphosphonates on the S0307 clinical trial. Women were randomized to receive zoledronic acid, oral clodronate or oral ibandronate in doses far higher than those used in osteoporosis treatment as per protocol. After 18–36 months of bisphosphonate therapy, participates underwent a one-time evaluation of areal bone mineral density (aBMD) of the 1/3 radius, lumbar spine, and hip by dual energy x-ray absorptiometry (DXA), and cortical and trabecular volumetric BMD (vBMD) and trabecular microarchitecture of the radius and tibia by HR-pQCT. HR-pQCT measurements were compared to healthy young premenopausal women and age-matched Caucasian women. Results: Baseline characteristics of the 12 enrolled patients: median age of 53 (range 40–67); white/Hispanics 7/5; pre/postmenopausal 4/8; mean body mass index 28.7 kg/m2 (20.9–34.8); average time on bisphosphonates 20 months (18–30); zoledronic acid/clodronate/ibandronate 5/6/1. The median aBMD DXA T-score of the 1/3 radius, lumbar spine and total hip were normal at +0.3, +0.1, and +0.2, respectively. Mean total, cortical, and trabecular vBMD of the radius as measured by HR-pQCT were 330±71, 905±55, and 146±35 mg hydroxyapatite/cm3, respectively. Mean cortical thickness was 0.803±0.170 mm, and mean trabecular number was 1.9±0.2. Mean total, cortical, and trabecular vBMD of the tibia were 285±54, 880±54, and 150±38 mg hydroxyapatite/cm3, respectively. Mean cortical thickness was 1.135±0.264 mm, and mean trabecular number was 1.7±0.3. There were no statistically significant differences between study group and each control. However, results were more similar to healthy young premenopausal control than the age-matched control. Conclusion: Women on long-term bisphosphonate therapy for breast cancer had normal aBMD by DXA and normal cortical and trabecular vBMD, cortical thickness and trabecular number at the peripheral skeleton compared to healthy young women and age-matched women. This preliminary data is reassuring for cancer survivors if benefits from this therapy are established in the adjuvant setting. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-12-03.

Bone mineral density measurements of the proximal femur from routine contrast-enhanced MDCT data sets correlate with dual-energy X-ray absorptiometry

To evaluate the utility of femoral bone mineral density (BMD) measurements in routine contrast-enhanced multi-detector computed tomography (ceMDCT) using dual-energy X-ray absorptiometry (DXA) as the reference standard. Forty-one patients (33 women, 8 men) underwent DXA measurement of the proximal femur. Subsequently, transverse sections of routine ceMDCT of these patients were used to measure BMD of the femoral head and femoral neck. The MDCT-to-DXA conversion equations for BMD and T-score were calculated using linear regression analysis. The conversion equations were applied to the MDCT data sets of 382 patients (120 women, 262 men) of whom 74 had osteoporotic fractures. A correlation coefficient of r = 0.84 (P < 0.05) was calculated for BMD(MDCT) values of the femoral head and DXA T-scores of the total proximal femur using the conversion equation T-score = 0.021 × BMD(MDCT) - 5.90. The correlation coefficient for the femoral neck was r = 0.79 (P < 0.05) with the conversion equation T-score = 0.016 × BMD(MDCT) - 4.28. Accordingly, converted T-scores for the femoral neck in patients with versus those without osteoporotic fractures were significantly different (female, -1.83 versus -1.47; male, -1.86 versus -1.47; P < 0.05). BMD measurements of the proximal femur were computed in routine contrast-enhanced MDCT and converted to DXA T-scores, which adequately differentiated patients with and without osteoporotic fractures.

Individual trabecula segmentation (ITS)-based morphological analyses and microfinite element analysis of HR-pQCT images discriminate postmenopausal fragility fractures independent of DXA measurements.

Osteoporosis is typically diagnosed by dual-energy X-ray absorptiometry (DXA) measurements of areal bone mineral density (aBMD). Emerging technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), may increase the diagnostic accuracy of DXA and enhance our mechanistic understanding of decreased bone strength in osteoporosis. Women with (n = 68) and without (n = 101) a history of postmenopausal fragility fracture had aBMD measured by DXA, trabecular plate and rod microarchitecture measured by HR-pQCT image-based individual trabecula segmentation (ITS) analysis, and whole bone and trabecular bone stiffness by microfinite element analysis (µFEA) of HR-pQCT images at the radius and tibia. DXA T-scores were similar in women with and without fractures at the spine, hip, and 1/3 radius, but lower in fracture subjects at the ultradistal radius. Trabecular microarchitecture of fracture subjects was characterized by preferential reductions in trabecular plate bone volume, number, and connectivity over rod trabecular parameters, loss of axially aligned trabeculae, and a more rod-like trabecular network. In addition, decreased thickness and size of trabecular plates were observed at the tibia. The differences between groups were greater at the radius than the tibia for plate number, rod bone volume fraction and number, and plate-rod and rod-rod junction densities. Most differences between groups remained after adjustment for T-score by DXA. At a fixed bone volume fraction, trabecular plate volume, number, and connectivity were directly associated with bone stiffness. In contrast, rod volume, number, and connectivity were inversely associated with bone stiffness. In summary, HR-pQCT-based ITS and µFEA measurements discriminate fracture status in postmenopausal women independent of DXA measurements. Moreover, these results suggest that preferential loss of plate-like trabeculae contribute to lower trabecular bone and whole bone stiffness in women with fractures. We conclude that HR-pQCT-based ITS and µFEA measurements increase our understanding of the microstructural pathogenesis of fragility fracture in postmenopausal women.

Medikamentöse Osteoporoseprophylaxe und -therapie bei Patienten mit rheumatoider Arthritis (ORA-Studie)

The aim of this study was to examine bone mineral density (BMD), frequency of osteopenia and osteoporosis in a representative sample of patients with rheumatoid arthritis (RA) and to describe chemoprophylaxis and treatment of osteoporosis compared to evidence-based guidelines. In 2005 and 2006, 532 patients with RA (98 men, 434 women) aged 23-87 years were recruited from 9 German rheumatology centers. Clinical examination included a detailed documentation of osteoporosis medication. Dual-energy X-ray absorptiometry (DXA) was used to measure BMD at the lumbar spine and femoral neck. Osteopenia and osteoporosis were defined according to the criteria of the World Health Organization. Of the RA patients 29% had normal BMD at the spine and femoral neck, 49% of the patients had osteopenia and 22% met the criteria for osteoporosis at any site. Of the patients 60% were receiving medication for prophylaxis or therapy of osteoporosis, 38% calcium/vitamin D alone, 20% as combinations mostly of calcium/vitamin D + bisphosphonate, 1% received bisphosphonate only and 1% hormone replacement therapy. Although the frequency of osteoporosis showed no significant differences between male and female patients, women with RA used osteoporosis medication more often than men (63% versus 49%, χ²-test, p <0.05). A total of 101 RA patients (83 menopausal women, 6 premenopausal women, 12 men) received corticosteroids in a daily dose of 7.5 mg or less for at least 3 months and had DXA T-scores below -2.0 at any site. In this patient group 41% of the menopausal women, 17% of the premenopausal women and 42% of the male patients were reported to receive medication with calcium/vitamin D + bisphosphonate. Calcium/vitamin D was used by 35% of the menopausal women, none of the premenopausal women and 50% of the male patients and 18% of the menopausal women, 67% of the premenopausal women and 8% of men received no prophylaxis or treatment for osteoporosis. According to the DVO (German Society for Osteoporosis) guidelines for osteoporosis (2009) menopausal women with corticosteroid therapy < 7.5 mg per day for at least 3 months and DXA T-scores below -2.0 should receive treatment with bisphosphonate and calcium/vitamin D. The data show that there were still deficits concerning prophylaxis and treatment of osteoporosis in RA.

The prevalence of vitamin D deficiency and relationship with fracture risk in older women presenting in Australian general practice

To investigate vitamin D status among older women and to explore relationships between vitamin D and fracture risk and vertebral fractures. A total of 267 general practitioners recruited 2466 women aged >70 years with no known osteoporosis or fragility fracture. Serum 25-hydroxy vitamin D (25(OH)D), bone mineral density by dual-energy X-ray absorptiometry (DXA) and vertebral fracture on thoracolumbar X-ray were determined. A total of 2368 women, median age 76 years, provided data and of these 13% were on vitamin D supplements. 25(OH)D levels were available for 907 (44.1%) of those not taking vitamin D. 88.3% of these had a level below 75 nmol/L. Serum 25(OH)D was negatively associated with age (P = 0.003) and body mass index (P < 0.001), and positively associated with lower latitude, femoral neck DXA T-score (P = 0.044) and being Caucasian (P < 0.001). The vitamin D status of community-dwelling older Australian women is inadequate, yet the use of supplements is low.

Simultaneous screening for osteoporosis at CT colonography: Bone mineral density assessment using MDCT attenuation techniques compared with the DXA reference standard

The purpose of this study was to evaluate the utility of lumbar spine attenuation measurement for bone mineral density (BMD) assessment at screening computed tomographic colonography (CTC) using central dual-energy X-ray absorptiometry (DXA) as the reference standard. Two-hundred and fifty-two adults (240 women and 12 men; mean age 58.9 years) underwent CTC screening and central DXA BMD measurement within 2 months (mean interval 25.0 days). The lowest DXA T-score between the spine and hip served as the reference standard, with low BMD defined per World Health Organization as osteoporosis (DXA T-score ≤ -2.5) or osteopenia (DXA T-score between -1.0 and -2.4). Both phantomless quantitative computed tomography (QCT) and simple nonangled region-of-interest (ROI) multi-detector CT (MDCT) attenuation measurements were applied to the T(12) -L(5) levels. The ability to predict osteoporosis and low BMD (osteoporosis or osteopenia) by DXA was assessed. A BMD cut-off of 90 mg/mL at phantomless QCT yielded 100% sensitivity for osteoporosis (29 of 29) and a specificity of 63.8% (143 of 224); 87.2% (96 of 110) below this threshold had low BMD and 49.6% (69 of 139) above this threshold had normal BMD at DXA. At L(1) , a trabecular ROI attenuation cut-off of 160 HU was 100% sensitive for osteoporosis (29 of 29), with a specificity of 46.4% (104 of 224); 83.9% (125 of 149) below this threshold had low BMD and 57.5% (59/103) above had normal BMD at DXA. ROI performance was similar at all individual T(12) -L(5) levels. At ROC analysis, AUC for osteoporosis was 0.888 for phantomless QCT [95% confidence interval (CI) 0.780-0.946] and ranged from 0.825 to 0.853 using trabecular ROIs at single lumbar levels (0.864; 95% CI 0.752-0.930 at multivariate analysis). Supine-prone reproducibility was better with the simple ROI method compared with QCT. It is concluded that both phantomless QCT and simple ROI attenuation measurements of the lumbar spine are effective for BMD screening at CTC with high sensitivity for osteoporosis, as defined by the DXA T-score.

Abnormal microarchitecture and reduced stiffness at the radius and tibia in postmenopausal women with fractures

Measurement of areal bone mineral density (aBMD) by dual-energy x-ray absorptiometry (DXA) has been shown to predict fracture risk. High-resolution peripheral quantitative computed tomography (HR-pQCT) yields additional information about volumetric BMD (vBMD), microarchitecture, and strength that may increase understanding of fracture susceptibility. Women with (n = 68) and without (n = 101) a history of postmenopausal fragility fracture had aBMD measured by DXA and trabecular and cortical vBMD and trabecular microarchitecture of the radius and tibia measured by HR-pQCT. Finite-element analysis (FEA) of HR-pQCT scans was performed to estimate bone stiffness. DXA T-scores were similar in women with and without fracture at the spine, hip, and one-third radius but lower in patients with fracture at the ultradistal radius (p < .01). At the radius fracture, patients had lower total density, cortical thickness, trabecular density, number, thickness, higher trabecular separation and network heterogeneity (p < .0001 to .04). At the tibia, total, cortical, and trabecular density and cortical and trabecular thickness were lower in fracture patients (p < .0001 to .03). The differences between groups were greater at the radius than at the tibia for inner trabecular density, number, trabecular separation, and network heterogeneity (p < .01 to .05). Stiffness was reduced in fracture patients, more markedly at the radius (41% to 44%) than at the tibia (15% to 20%). Women with fractures had reduced vBMD, microarchitectural deterioration, and decreased strength. These differences were more prominent at the radius than at the tibia. HR-pQCT and FEA measurements of peripheral sites are associated with fracture prevalence and may increase understanding of the role of microarchitectural deterioration in fracture susceptibility. © 2010 American Society for Bone and Mineral Research.

Accuracy of quantitative ultrasound parameters in the diagnosis of osteoporosis

Abstract Quantitative ultrasound (QUS) is of increasing interest for evaluation of osteoporosis because, compared with dual-energy X-ray absorptiometry (DXA), it is portable, less expensive, and radiation-free. The aim of our study was to determine the sensitivity, specificity, and cut-off values of quantitative ultrasound parameters in identifying patients with osteoporosis compared to the World Health Organization (WHO) standard definition. We performed a cross-sectional investigational study of 73 subjects, and determined total hip and lumbar spine T-scores by dual-energy X-ray absorptiometry (DXA) (Prodigy Advance Lunar-GE). The QUS parameters (broadband ultrasound attenuation [BUA], speed of sound, bone mineral density, the stiffness index, and QUS T-score) were determined with Sahara Hologic equipment. The AUC was 0.81 (95% CI 0.67–0.95, p&lt;0.05) for speed of sound (SOS) and 0.76 (95% CI 0.62–0.90, p&lt;0.05) for BUA for the patients with DXA T-scores ≥ −1 DS; the cut-off values were 1542.2 meters per second for SOS and 63.3 dB/MHz for BUA. In patients with DXA T-scores ≤ − 2.5 DS, AUC was 0.80 (95% CI 0.70–0.90, p&lt;0.05) for SOS, and 0.76 (95% CI 0.65–0.87, p&lt;0.05) for BUA. The cut-off values were 1504.95 meters per second for SOS and 49.5 dB/MHz for BUA. Pearson correlation coefficients were positive and statistically significant (&gt; 50%) for all QUS parameters in both groups, (2-tailed, p&lt;0.05). QUS parameters correctly identified normal patients (false negative 34.21% and false positive 2.53%) and those with osteoporosis (false negative 8.55% and false positive 7.82%). The patients with QUS parameters between the cut-off values corresponding to DXA T-scores of −1 SD and − 2.5 SD should be further evaluated by DXA.