Journal of Clinical Densitometry - Articles in Press

Intrarater Reliability of Dual-Energy X-Ray Absorptiometry–Based Measures of Vertebral Height in Postmenopausal Women - Corrected Proof

Alison M. Bonnyman, Colin E. Webber, Paul W. Stratford, Norma J. MacIntyre — 2012-05-14

Abstract: The primary purpose was to estimate intrarater reliability of vertebral body height (VH) measures in postmenopausal women based on duplicate analyses of vertebral fracture assessment (VFA) images. The secondary purpose was to determine the consistency in classification of vertebral deformity on duplicate analyses. Thirty-two VFA were randomly selected from a database of 464 scans acquired in postmenopausal women using dual-energy X-ray absorptiometry (Discovery A; Hologic Inc., Waltham, MA). Visible endplates were marked on each image on 2 occasions (4wk apart) by a single rater; the semiautomated software derived measures of anterior, middle, and posterior VH and classified severity of vertebral deformity. Intrarater reliability was assessed using the intraclass correlation coefficient (with 95% confidence interval [CI]) when ≥22 VFA could be analyzed. Reliability of grading deformity of 267 vertebrae was assessed using Cohen’s unweighted kappa (with 95% CI). Reliability of anterior, middle, and posterior height measures from T8 to L4 was 0.85 and greater except for T8 anterior VH and T9 posterior VH (0.76 [0.43, 0.90] and 0.62 [0.15, 0.83], respectively). Chance-corrected agreement for 4 grades of vertebral deformity was 0.48 (0.30, 0.66) and for 2 categories (normal/mild and moderate/severe) was 0.70 (50, 0.90). Intrarater reliability was acceptable for VH measures from T10 to L4. Reliability in grading severity of deformity was improved by classifying as <25% deformity (nonfracture) and as >25% deformity (fracture).

The Associations of Body Composition and Fat Distribution With Bone Mineral Density in Elderly Italian Men and Women - Corrected Proof

2012-05-11

Abstract: This study aimed to investigate the associations of body composition and fat distribution with bone mineral density (BMD) in elderly Italian subjects. In 866 women (age 64.2±6.5yr) and 168 men (age 65.1±6.1yr), we measured BMD at lumbar spine, at femur, at the total body, and at the right hand. In all subjects, we also measured sex hormones, 25-hydroxyvitamin D, bone markers, and calcium intake. In both men and women, all body composition parameters had significant positive correlations with BMD at all sites after adjusting for age only; after adjusting also for body weight only lean mass (LM) remained positively associated with BMD at all sites except BMD at lumbar spine. In males, LM was associated with BMD at all sites, whereas android fat was associated with BMD at lumbar spine, at femur, and at whole body. In females, fat mass (FM) was positively and age inversely associated with BMD at all sites, whereas gynoid fat and alkaline phosphatase were inversely associated with BMD at lumbar spine and at femur. In conclusion, the role of LM seems more important in males, whereas in women the role of FM prevails with negative associations between gynoid fat and BMD.

Denosumab Densitometric Changes Assessed by Quantitative Computed Tomography at the Spine and Hip in Postmenopausal Women With Osteoporosis - Corrected Proof

2012-05-10

Abstract: FREEDOM was a phase 3 trial in 7808 women aged 60–90yr with postmenopausal osteoporosis. Subjects received placebo or 60 mg denosumab subcutaneously every 6mo for 3yr in addition to daily calcium and vitamin D. Denosumab significantly decreased bone turnover; increased dual-energy X-ray absorptiometry (DXA) areal bone mineral density (aBMD); and significantly reduced new vertebral, nonvertebral, and hip fractures. In a subset of women (N=209), lumbar spine, total hip, and femoral neck volumetric BMD (vBMD) were assessed by quantitative computed tomography at baseline and months 12, 24, and 36. Significant improvement from placebo and baseline was observed in aBMD and vBMD in the denosumab-treated subjects at all sites and time points measured. The vBMD difference from placebo reached 21.8%, 7.8%, and 5.9%, respectively, for the lumbar spine, total hip, and femoral neck at 36mo (all p≤0.0001). Compared with placebo and baseline, significant increases were also observed in bone mineral content (BMC) at the total hip (p<0.0001) largely related to significant BMC improvement in the cortical compartment (p<0.0001). These results supplement the data from DXA on the positive effect of denosumab on BMD in both the cortical and trabecular compartments.

Threshold-Free Automatic Detection of Cortical Bone Geometry by Peripheral Quantitative Computed Tomography - Corrected Proof

Tomas Cervinka, Jari Hyttinen, Harri Sievänen — 2012-05-10

Abstract: An accurate assessment of bone strength is an important goal in clinical bone research. For appropriate information on bone strength, precise segmentation of actual cross-sectional bone geometry is needed. In this article, we introduce an automatic, simple, and fast approach for reliable segmentation of cortical bone cross-sectional area based on the outer boundary detection and subsequent shrinking (OBS) procedure. Using repeated in vivo peripheral quantitative computed tomography (pQCT) images of distal tibia from 25 subjects, we compared new segmentation results with those obtained from commonly applied simple density thresholds and from a recent advanced analysis based on distance regularized level set evolution (DRLSE). Manual segmentation of cortical bone done by 3 independent evaluators was considered a gold standard. The new approach showed nearly 50% less variation in error compared with threshold-based analysis in conjunction with a recently introduced statistical preprocessing method and agreed well with results obtained from manual segmentation. The DRLSE segmentation resulted consistently in ∼15% mean overestimation of all geometrical traits with a similar variation of data as obtained from the OBS method. In conclusion, the OBS method improved assessment of all observed measures of cortical geometry and can enhance the cortical bone analysis of pQCT images in clinical research studies.

Femoral Fractures in Osteoporotic Patients on Bisphosphnates. A Case Report - Corrected Proof

Fahad Alshahrani, David Kendler — 2012-05-10

Abstract: Osteoporotic fractures and particularly hip fractures represent a considerable burden of illness in the elderly. Bisphosphonates (BP) have been used extensively over the past decade and a half for the management of osteoporosis with considerable clinical benefit in the reduction of fragility fractures. Although not apparent in clinical trials, rare associations of subtrochanteric atypical femoral fractures (AFF) have been reported postmarketing, often after long-term BP therapy. Here, we report a well-characterized Asian female patient with bilateral AFF after long-term etidronate and alendronate therapy.

Discrepancy Between the Quantitative Ultrasound Value of Malaysian Men and the Manufacturer’s Reference and the Impact on Classification of Bone Health Status - Corrected Proof

2012-05-10

Abstract: The local normative value in quantitative ultrasound (QUS) equipment needs to be established for wider application and accurate classification of patients into respective fracture risk groups. The present study aimed to establish the calcaneal speed of sound (SOS) value for Chinese and Malay men in Malaysia and determine the difference between calcaneal SOS of the local population and the reference values provided by the manufacturer for each age group. This study will also determine the effect of using the manufacturer’s young adult (20–29yr) reference or the local young adult reference to classify the subjects into the respective risk groups. Eight hundred forty Malay and Chinese men residing in central peninsular Malaysia were recruited and their calcaneal QUS value was determined using the CM-200 machine (Furuno Electric, Nishinomiya City, Japan). The results showed that the differences in SOS values between Chinese and Malay men were not significant across all the age groups studied (p>0.05). The age-dependent reduction of SOS value assumed a biphasic form, which was evident at 30–39yr and older than 60yr. The calcaneal SOS of the subject under study was significantly higher as compared with the manufacturer’s reference (based on Japanese population) in all groups aged 40yr and older (p<0.05). A significant proportion of the subjects in the osteoporosis group was misclassified using the manufacturer’s young adult reference as compared with using the local young adult reference (p<0.05). In conclusion, the overall normative value of SOS obtained was suitable for Chinese and Malay men in Malaysia, and a local reference value should be applied to avoid misclassification of subjects into the respective risk groups.

Comparison of Cortical Bone Measurements Between pQCT and HR-pQCT - Corrected Proof

Deena Lala, Angela M. Cheung, Chris Gordon, Lora Giangregorio — 2012-04-30

Abstract: The primary purpose of this study was to determine the accuracy of tibial cortical thickness measurements derived from peripheral quantitative computed tomography (pQCT) with analysis based on the circular ring model, using high-resolution peripheral quantitative computed tomography (HR-pQCT) (isotopic voxel size of 82μm) as a gold standard. The secondary objective was to evaluate whether the accuracy of the pQCT-based estimates of cortical thickness (CTh), cortical area (CoA), cortical density (CDen), and total area (TotA) improve with alterations of voxel size from the standard 0.5–0.2mm. Fifteen dry tibia specimens were immersed in saline in a sealed cylinder and scanned 22.5mm from the distal tibia plateau using pQCT and HR-pQCT. pQCT yielded higher values for CTh and CDen and lower values for CoA. The differences between imaging techniques increased as the average CTh increased. No systematic bias was observed for CDen, CoA, and TotA. Similar differences were found between pQCT with voxel size 0.2mm and HR-pQCT. Significant correlations were observed for CTh (R=0.97, p≤0.0001), CDen (R=0.99, p≤0.0001), CoA (R=0.98, p≤0.0001), and TotA (R=1.0, p≤0.0001) when pQCT- and HR-pQCT-derived values were compared irrespective of which voxel size was used. Measurement variability between the imaging techniques was evident. Future studies aimed at examining cortical structure with pQCT should note that there are differences between the 2 techniques.

The Role of Distal Third Radius Dual Energy X-ray Absorptiometry (DXA) and Central DXA in Evaluating for Osteopenia and Osteoporosis in Men Receiving Androgen Deprivation Therapy for Prostate Cancer - Corrected Proof

2012-04-30

Abstract: The authors assessed the use of distal third radius dual energy X-ray absorptiometry (DXA) concomitantly with central (hip and lumbar spine) DXA to identify men with osteopenia or osteoporosis receiving androgen deprivation therapy (ADT) for prostate cancer. Initial classification with central DXA demonstrated 60 (17%) normal, 187 (55%) osteopenic, and 96 (28%) osteoporotic patients. Sixteen of 60 (27%) normal patients were reclassified as osteopenic (14) or osteoporotic (2), and 20 of 187 (11%) osteopenic patients were reclassified as osteoporotic with the combination of central DXA plus distal third radius DXA. The difference in reclassification was statistically significant. The addition of distal third radius to central DXA scanning in men with bone loss associated with ADT identifies a statistically significant number of men being reclassified as having osteopenia or osteoporosis. Combined central and distal third radius DXA scanning should be considered routine in the evaluation of all men suspected of bone loss associated with ADT. This has specific significant clinical relevance because of the large number of men with nonevaluable central DXA studies. Fracture risk prediction and treatment recommendations based on this reclassification will need to be determined by follow-up studies.

Precision of GE Lunar iDXA for the Measurement of Total and Regional Body Composition in Nonobese Adults - Corrected Proof

2012-04-30

Abstract: Dual-energy X-ray absorptiometry (DXA) is a well-accepted technique for measuring body composition. Knowledge of measurement precision is critical for monitoring of changes in bone mineral content (BMC), and fat and lean masses. The purpose of this study was to characterize in vivo precision of total body and regional body composition parameters using the GE Lunar iDXA (GE Healthcare Lunar, Madison, WI) system in a sample of nonobese subjects. We also evaluated the difference between expert and automatic region-of-interest (ROI) analysis on body composition precision. To this end, 2 total body scans were performed on each subject with repositioning between scans. Total body precision for BMC, fat and lean mass were 0.5%, 1.0%, and 0.5% coefficient of variation (CV), respectively. Regional body composition precision error was less than 2.5% CV for all regions except arms. Precision error was higher for the arms (CV: BMC 1.5%; fat mass 2.8%; lean mass 1.6%), likely owing to the placement of arms relative to torso leading to differences in ROI. There was a significant correlation between auto ROI and expert ROI (r>0.99). Small, but statistically significant differences were found between auto and manual ROI. Differences were small in total body, leg, trunk, and android and gynoid regions (0.004–2.8%), but larger in arm region (3.0–6.3%). Total body and regional precision for iDXA are small and it is suggested that iDXA may be useful for monitoring changes in body composition during longitudinal trials.

Role of B12 and Homocysteine Status in Determining BMD and Bone Turnover in Young Indians - Corrected Proof

Nisha Nigil Haroon, Raman K. Marwaha, Madan M. Godbole, Sushil K. Gupta — 2012-04-23

Abstract: Vitamin B12 (B12) deficiency and hyperhomocysteinemia (HHcy) are independent risk factors for low bone mineral density (BMD) and fracture risk. We studied the role of HHcy and B12 deficiency in determining the peak bone mass in Indians. Randomly selected 151 healthy young adult subjects (females 100, mean age: 26yr) underwent evaluation of dietary intake of calcium and B12; sun exposure; estimation of BMD by dual-energy X-ray absorptiometry at total hip, forearm, and lumbar spine; serum 25(OH)D3; intact parathyroid hormone; B12; homocysteine (Hcy); and bone turnover markers (BTMs) serum crosslaps, N-mid osteocalcin, and bone-specific alkaline phosphatase. Hypovitaminosis D (serum 25OHD3<20ng/mL) and serum ALP level >150IU/L were seen in 83% and 27%, respectively. Median serum B12 and Hcy levels were 140pg/mL (interquartile range [IQR]: 72–230pg/mL) and 18μmol/L (IQR 14–32μmol/L); B12 deficiency (serum B12<200pg/mL) and HHcy (serum Hcy>30μmol/L) were present in 71% and 68%, respectively. Low BMD (Z-score <−2.0) was present in 17% of subjects. There was no significant correlation between serum Hcy, folate, B12, BTM, and BMD. BMD was predicted by height, weight, and body mass index. Young Indian healthy adults have high prevalence of hypovitaminosis D, B12 deficiency, and HHcy. There is no correlation of serum B12, folate, and Hcy status with BTMs and BMD in young, healthy, vegetarian Indian adults. Anthropometric variables predict BMD in young Indians.

Radiograph-Based Study of Gender-Specific Vertebral Area Gain in Healthy Children and Adolescents as a Function of Age, Height, and Weight - Corrected Proof

2012-04-23

Abstract: This study reports gender-specific vertebral area gain data from children and adolescents. Vertebral area was measured on lateral and anteroposterior thoracic and lumbar spine radiographs from 100 female and 100male subjects aged 7–28yr. T9, T11, T12, L1, and L2 X-ray area calculation was based on calculation of the area of the geometric figure of a trapezoid whose 2 nonparallel sides were equal in length, taking account of the waisted shape of the vertebrae. Both the boys and girls of our study population showed statistically significant dependence (p<0.001) of vertebral area gain on chronologic age, height, and weight right through the end of puberty, and especially so up to age 15yr. However, height and weight were clearly better predictors of lateral and anteroposterior vertebral area gain than was chronologic age. Once vertebral growth is complete by age 18yr or so, the lateral vertebral areas of the male subjects—regardless of body weight and height—are, on average, 25% larger, and the anteroposterior areas up to 30% larger than those of their female counterparts. After adjusting for chronologic age, height, and weight however we did not find significant differences, between gender, in vertebral area of male and female subjects, neither among children younger than 11yr nor adolescents ages of 12–14yr and young adults older than 18yr.

Fat and Muscle Indices Assessed by pQCT: Relationships With Physical Activity and Type 2 Diabetes Risk - Corrected Proof

2012-04-23

Abstract: The aim of this study was to compare and determine the repeatability of foreleg and forearm muscle and fat indices evaluated by the peripheral quantitative computed tomography (pQCT). Effects of habitual physical activity and associated health risk of type 2 diabetes were examined within the interrelations of intermuscular adipose tissue (IMAT) and muscle density.Eighty-two premenopausal women (mean age±standard deviation: 38.6±4.7yr) underwent dual-energy X-ray absorptiometry scans and pQCT of foreleg and forearm scans to assess muscle and fat parameters. Physical activity status was based on 4-d self-reported log and pedometer step counts.Fat and muscle distribution between the foreleg and forearm were similar and highly correlated to total body adiposity. The pQCT device reliably measured muscle density in the foreleg and forearm; coefficients of variation were 0.8% and 2.1%, which was therefore used to reflect IMAT status. Muscle density was positively related to physical activity and negatively associated with markers of fat distribution and risk for type 2 diabetes.The pQCT is a novel, noninvasive tool to assess IMAT and muscle density in the foreleg and forearm. Additional research is necessary to understand the biology of IMAT and its relations with physical activity and potentially, with risks for cardiometabolic disease.

Lean Mass Predicts Hip Geometry and Bone Mineral Density in Chinese Men and Women and Age Comparisons of Body Composition - Corrected Proof

2012-04-23

Abstract: Previous studies have suggested that changes in hip geometry increase the risk of hip fracture. The aim of this study was to identify whether body composition were associated with hip geometry or bone mineral density (BMD) in a large sample of Chinese people. A total of 2072 subjects aged 20–79yr (including 700 males and 1372 females) were selected. The following measurements were taken: lumbar spine (L1–4); proximal femur BMD; lean mass (LM); fat mass (FM); and hip geometric parameters, including hip axis length (HAL), cross-sectional moment of inertia (CSMI), cross-sectional area (CSA), neck-shaft angle, and femur strength index (SI) by dual-energy X-ray absorptiometry. FM and LM were positively correlated with HAL, CSMI, and CSA, and negatively correlated with SI in both men and women. Multiple regression analysis showed that leg LM contributions to HAL, CSMI, and CSA variance were 12.6–37.6%. Compared with FM, LM was generally more strongly related to hip geometry and BMD in young and old men and women. Body composition was a good predictor for hip geometry parameter variation and BMD variation.

The Importance of Absolute Bone Mineral Density in the Assessment of Antiresorptive Agents Used for the Prevention of Osteoporotic Fractures - Corrected Proof

Tatsuhiko Kuroda, Masataka Shiraki, Yumiko Shiraki, Shiro Tanaka — 2012-04-23

Abstract: The usefulness of bone mineral density (BMD) monitoring during antiresorptive treatment is still controversial. This study aimed to determine which factors of change (absolute value or the percent change from the baseline) in BMD are associated with the risk of future fractures. A total of 565 postmenopausal osteoporosis who were treated antiresorptive drugs were included in this prospective observational study. Lumbar BMD (LBMD) was measured at baseline and 1-yr after the initial and subsequent incident fracture was observed. The percent changes in LBMD at 1yr were 5.4±6.4% and 118 (20.9%) achieved increased LBMD with change of classification to >−2.5 standard deviation (SD). After the initial 1-yr examination, incident fractures developed in 152 (26.9%). The incident fracture risk was significantly associated with the absolute value in LBMD, but not with the percent change. A Cox proportional hazard model demonstrated that increased LBMD with change of classification to >−2.5 SD was a significant predictor for a reduction in incident fractures (hazard ratio: 0.41, 95% confidence interval: 0.21–0.71). In conclusion, these results suggest that monitoring of the antifracture efficacy of antiresorptive treatments should be based on the absolute value of BMD. In particular, increased change to >−2.5 SD is important for reducing the future fracture risk.

Denosumab Significantly Increases DXA BMD at Both Trabecular and Cortical Sites: Results From the FREEDOM Study - Corrected Proof

2012-04-23

Abstract: Denosumab is an approved therapy for postmenopausal women with osteoporosis at high or increased risk for fracture. In the FREEDOM study, denosumab reduced fracture risk and increased bone mineral density (BMD). We report the spine and hip dual-energy X-ray absorptiometry (DXA) BMD responses from the overall study of 7808 women and from a substudy of 441 participants in which more extensive spine and hip assessments as well as additional skeletal sites were evaluated. Significant BMD improvements were observed as early as 1mo at the lumbar spine, total hip, and trochanter (all p<0.005 vs placebo and baseline). BMD increased progressively at the lumbar spine, total hip, femoral neck, trochanter, 1/3 radius, and total body from baseline to months 12, 24, and 36 (all p<0.005 vs placebo and baseline). BMD gains above the least significant change of more than 3% at 36 months were observed in 90% of denosumab-treated subjects at the lumbar spine and 74% at the total hip, and gains more than 6% occurred in 77% and 38%, respectively. In conclusion, denosumab treatment resulted in significant, early, and continued BMD increases at both trabecular and cortical sites throughout the skeleton over 36mo with important gains observed in most subjects.

X-ray Knee as a Screening Tool for Osteoporosis - Corrected Proof

2012-04-23

Abstract: Cortical thickness (Cor-Th) of tibia varies considerably on X-ray knees. It was hypothesized that Cor-Th can be used for preliminary prediction of BMD. Ninety nine patients underwent a digital X-ray left knee fixed flexion PA view with an external calibration scale attached to X-ray plate and BMD by DXA using GE lunar machine (Madison, Wisconsin.). Cor-Th was measured at 5 selected levels (A,B,C,D, and E) ranging from 5–7cm below the tibial plateau on its medial aspect. T-scores were recorded for BMD at AP spine, left forearm and left femur. Cor-Th of tibia at each level significantly correlated with each site of BMD measurement namely AP spine, left femur and left forearm. This correlation varied in the range from 0.241 to 0.426. For AP spine, it was maximum at level C (r=0.347, p<0.001) whereas for left femur and forearm sites, it was maximum at level B (r=0.426 & r=0.373 respectively, p<0.001). The correlation of Cor-Th with BMD varied with age. Above 56 years of age, Cor-Th at each level significantly correlated to BMD at each site. Medial tibial cortical thickness, 6cm (level C) below tibial plateau can be used as preliminary predictor of patients who need a DXA scan.

Identification of Rheumatoid Arthritis Patients With Vertebral Fractures Using Bone Mineral Density and Trabecular Bone Score - Corrected Proof

2012-03-23

Abstract: The aim of this study was to test bone mineral density (BMD), trabecular bone score (TBS), and their combination, for detection of rheumatoid arthritis (RA) patients with vertebral fractures (VFs). One hundred eighty-five women aged 56.0±13.5yr, with RA since 15.5±9.9yr were studied. Lumbar spine, total hip, and femoral neck BMD were assessed by dual-energy X-ray absorptiometry (DXA). TBS was calculated from anteroposterior image of lumbar spine BMD. VFs from T4 to L4 were evaluated using Vertebral Fracture Assessment software on DXA device. The proportions of patients with VF and T-scores ≤−2.5 were only 24.2%, 21.2%, and 33.3% at lumbar spine, total hip, and femoral neck, respectively. T-scores were significantly lower in patients with VF than in patients without VF, the largest difference being observed at femoral neck (p=0.0001). TBS was significantly lower in patients with VF vs without VF (p=0.0001). The areas under the curves were 0.621, 0.704, 0.703, 0.719, and 0.727 for lumbar spine BMD, TBS, lumbar spine BMD+TBS, total hip BMD, and femoral neck BMD, respectively. The threshold of 1.173 for TBS had the best sensitivity (63%) and specificity (74%). TBS measured at the lumbar spine has a better discrimination value than lumbar spine BMD, and similar to femoral neck BMD, for prediction of presence of VF in patients with RA. In RA subjects with osteopenia, the proportion of patients with VF was higher in the lowest tertile of TBS when compared with the highest tertile. In this population, at low risk according to BMD, TBS could help to detect patients with VF.

Validation of FRC, a Fracture Risk Assessment Tool, in a Cohort of Older Men: The Osteoporotic Fractures in Men Study - Corrected Proof

2012-03-23

Abstract: We evaluated the performance of the Fracture Risk Calculator (FRC) in 5893 men who participated in the baseline visit (March 2000–April 2002) of the Osteoporotic Fractures in Men Study. FRC estimates for 10-yr hip and major osteoporotic (hip, clinical spine, forearm, and shoulder) fractures were calculated and compared with observed 10-yr fracture probabilities. Possible enhancement of the tool’s performance when bone mineral density (BMD) was included was evaluated by comparing areas under receiver operating characteristic curves and by Net Reclassification Improvement (NRI). A total of 5893 men were followed-up for an average of 8.4yr. For most quintiles of predicted fracture risk, the ratios of observed to predicted probabilities were close to unity. Area under the curves improved when BMD was included (p<0.001; 0.79 vs 0.71 for hip fracture and 0.70 vs 0.66 for major osteoporotic fracture, respectively). Using National Osteoporosis Foundation clinical treatment thresholds, BMD inclusion increased NRI significantly, 8.5% (p<0.01) for hip and 4.0% (p=0.01) for major osteoporotic fracture. We conclude that the FRC calibrates well with hip and major osteoporotic fractures observed among older men. Further, addition of BMD to the fracture risk calculation improves the tool’s performance.

Epidemiological Data on Osteoporosis in Women From the RAC-OST-POL Study - Corrected Proof

2012-03-19

Abstract: In the RAC-OST-POL study, epidemiological data were presented concerning osteoporosis in 625 women older than 55yr coming from the District of Raciborz in Poland. The mean age was 66.4±7.8yr. All the women fulfilled a questionnaire, gathering data on clinical risk factors of osteoporosis. Femoral neck (FN) and total hip (TH) were measured. The mean value of bone mineral density for FN was 0.862±0.129g/cm2, T-score −1.25±0.92, and Z-score 0.039±0.78, whereas the respective values for TH were 0.945±0.149g/cm2, −0.47±1.19, and 0.52±0.98. T-score for FN below −2.5 was noted in 59 women (9.5%) and for TH in 23 women (3.7%). One hundred seventy six women reported prior osteoporotic fracture(s) (28.2%). Falls were the most common clinical risk factor. The number of clinical risk factors was significantly higher in subjects with fracture history than in those without fracture records. The only first-line antiresorptive medications, used in the therapy for osteoporosis, included alendronate—42 subjects (6.7%). Estrogen therapy was prescribed in 135 women and 7 were treated with calcitonin. Calcium was administered in 94 patients and vitamin D in 84 women. In all the women on therapy, Z-score values were significantly lower than in untreated women. Concluding, the results of our epidemiological study demonstrate low treatment rate in women with history of low trauma fracture. Effective strategies are needed for prevention, especially in regard to falls, and management of this disease, in particular for improvement of the treatment rates in affected women with prior fracture, in general.

Dual-Energy X-Ray Absorptiometry Interpretation: A Simple Equation for Height Correction in Preteenage Children - Corrected Proof

Fan Zhang, Michael P. Whyte, Deborah Wenkert — 2012-03-19

Abstract: Dual-energy X-ray absorptiometry (DXA) results, even when corrected for age, gender, and ethnicity, can lead clinicians to erroneously diagnose osteoporosis in short healthy children and underdiagnose osteoporosis in tall children. We derived 2 simple equations for preteenagers

Heel Ultrasound Can Assess Maintenance of Bone Mass in Women With Breast Cancer - Corrected Proof

2012-03-19

Abstract: Postmenopausal women with early stage breast cancer are at increased risk for bone loss and fractures. Bisphosphonates can prevent bone loss, but little data are available on changes in bone mass assessed by heel quantitative ultrasound (QUS). Our objectives were to determine if (1) heel QUS would provide a reliable and accessible method for evaluation of changes in bone mass in women with breast cancer when compared with the current standard of bone mass measurement, dual-energy X-ray absorptiometry (DXA) and (2) oral risedronate could affect these changes. Eighty-six newly postmenopausal (up to 8yr) women with nonmetastatic breast cancer were randomized to risedronate, 35mg once weekly or placebo. Outcomes were changes in heel QUS bone mass measurements and conventional DXA-derived bone mineral density (BMD). Over 2yr, bone mass assessed by heel QUS remained stable in women on risedronate, whereas women on placebo had a 5.2% decrease (p≤0.05) in heel QUS bone mass. Both total hip BMD and femoral neck BMD assessed by DXA decreased by 1.6% (p≤0.05) in the placebo group and remained stable with risedronate. Spine BMD remained stable in both groups. Heel QUS was moderately associated with BMD measured by DXA at the total hip (r=0.50), femoral neck (r=0.40), and spine (r=0.46) at baseline (all p≤0.001). In conclusion, risedronate helps to maintain skeletal integrity as assessed by heel QUS for women with early stage breast cancer. Heel QUS is associated with DXA-derived BMD at other major axial sites and may be used to follow skeletal health and bone mass changes in these women.

In Vivo Precision of Dual-Energy X-ray Absorptiometry-Derived Hip Structural Analysis in Adults - Corrected Proof

Karen Hind, Brian Oldroyd, Anup Prajapati, Laura Rhodes — 2012-03-09

Abstract: Precision is integral to the monitoring of bone mineral density (BMD) change using dual-energy X-ray absorptiometry (DXA). Hip structural analysis (HSA) is a relatively recent method of assessing cross-sectional geometrical strength from the 2-dimensional images produced by DXA scans. By performing serial scans, we evaluated the in vivo precision of DXA-derived HSA in adults using a GE Lunar iDXA absorptiometer (GE Medical Systems, Madison, WI) in males and females (n=42), mean age of 34.5 (standard deviation [SD]: 8.5; range: 19.3–52.6)yr with a heterogeneous sample. Two consecutive intelligent DXA (iDXA) scans with repositioning of both femurs were conducted for each participant. The coefficient of variation, root-mean-square (RMS) averages of SD, and hence the least significant change (95%) were calculated. We found a high level of precision for BMD measurements of both the total hip and femoral neck, with RMS-SD=0.006 and 0.010g/cm2 and percent coefficient of variation (%CV)=0.52% and 0.94%, respectively. We also found good precision for HSA-derived geometrical properties, including sectional modulus, cross-sectional moment of inertia, and cross-sectional area, with %CV (average of the left and right sides) at 4.48%, 3.78%, and 3.13%, respectively. Precision was poorer for buckling ratio and femoral strength index with %CV 28.5% and 9.25%, respectively. The iDXA provides high precision for BMD measurements and with varying levels of precision for HSA geometrical properties.

Obesity Increases Precision Errors in Dual-Energy X-Ray Absorptiometry Measurements - Corrected Proof

2012-03-09

Abstract: The precision errors of dual-energy X-ray absorptiometry (DXA) measurements are important for monitoring osteoporosis. This study investigated the effect of body mass index (BMI) on precision errors for lumbar spine (LS), femoral neck (NOF), total hip (TH), and total body (TB) bone mineral density using the GE Lunar Prodigy. One hundred two women with BMIs ranging from 18.5 to 45.9kg/m2 were recruited. Participants had duplicate DXA scans of the LS, left hip, and TB with repositioning between scans. Participants were divided into 3 groups based on their BMI and the percentage coefficient of variation (%CV) calculated for each group. The %CVs for the normal (<25kg/m2) (n=48), overweight (25–30kg/m2) (n=26), and obese (>30kg/m2) (n=28) BMI groups, respectively, were LS BMD: 0.99%, 1.30%, and 1.68%; NOF BMD: 1.32%, 1.37%, and 2.00%; TH BMD: 0.85%, 0.88%, and 1.06%; TB BMD: 0.66%, 0.73%, and 0.91%. Statistically significant differences in precision error between the normal and obese groups were found for LS (p=0.0006), NOF (p=0.005), and TB BMD (p=0.025). These results suggest that serial measurements in obese subjects should be treated with caution because the least significant change may be larger than anticipated.

Homocysteine, Folate, and Vitamin B12 Levels and Vertebral Fracture Risk in Postmenopausal Women - Corrected Proof

2012-02-10

Abstract: The objective of this study was to examine the influence of homocysteine, vitamin B12, and folate on the prevalence of asymptomatic osteoporotic vertebral fractures (VFs) using vertebral fracture assessment (VFA) in postmenopausal women. The study cohort consisted of 188 consecutive postmenopausal women (mean age, weight, and body mass index of 57.9±8.5 [41–91]yr, 74.4±13.5 [38–150]kg, and 30.4±5.2 [17.1–50.7]kg/m2, respectively). Lateral VFA images and scans of the lumbar spine and proximal femur were obtained using a Lunar Prodigy Vision densitometer (GE Healthcare Inc., Waukesha, WI). VFs were defined using a combination of Genant's semiquantitative approach and morphometry. Fifty-eight (30.9%) patients had densitometric osteoporosis. VFs were identified using VFA in 76 (40.4%) patients: 61 women had grade 1 VFs and 15 had grade 2 or 3 VFs. No statistical difference was shown between the 3 groups (absence of VFs, VFs grade 1, and VFs grade 2/3) concerning the biological parameters. Comparison of patients according to quartiles of homocysteine levels showed that women in the highest quartile were older and had a lower bone mineral density (BMD); however, the prevalence of VFs was not statistically different from that of women in the other quartile groups. Stepwise regression analysis showed that homocysteine was not independently associated with the presence of VFs, which was mainly related to the osteoporotic status. Although a weak association was observed between hyperhomocysteinemia and low BMD and a trend to higher prevalence of grade 2/3 VFs was observed, our study did not confirm that homocysteine, vitamin B12, and folate status are important determinants of prevalent asymptomatic VFs in postmenopausal women.

The Prevalence of Low Bone Mineral Density in Brazilian Patients With Systemic Lupus Erythematosus and Its Relationship With the Disease Damage Index and Other Associated Factors - Corrected Proof

2012-02-10

Abstract: The aim of this study was to examine the prevalence of osteoporosis, osteopenia, and bone mineral density (BMD) less than the expected range based on age in patients with systemic lupus erythematosus (SLE) in a tropical region of Brazil and the relationship between reduced BMD and several associated factors, especially the SLE disease damage index (SDI). We scored 159 patients with creatinine clearance of 60mL/min or more for SDI, which was modified by excluding the osteoporosis item. For postmenopausal women and men older than 50yr, T-scores identified osteopenia ( −2.5) and osteoporosis (≤−2.5). For all patients, a Z-score of −2.0 or less identified BMD less than the expected range for age. Other variables that influence BMD were studied. The prevalence of osteoporosis, osteopenia, and BMD less than the expected range for age was 28%, 54%, and 29.6%, respectively. The Z-scores were significantly lower in patients with a modified SDI≥1 (mean±standard deviation [SD]=−1.45±1.18) compared with patients with a modified SDI=0 (mean±SD=−0.94±1.01; p=0.01). The lowest Z-score had a significant association with postmenopausal status (p=0.038) and significant correlations with the duration of glucocorticoid (GC) usage (p=0.033, r=−0.17), the cumulative amount of GC (p=0.000, r=−0.28), and parathyroid hormone levels (p=0.003, r=−0.24). A multiple linear regression revealed that the modified SDI (p=0.003) and the cumulative amount of GC (p=0.006) had significant independent associations with the lowest Z-score. In conclusion, a BMD less than the expected range for age occurs frequently in Brazilian patients with SLE independent of the renal failure. The patients with greater SDIs had lower Z-scores, which suggests a direct association between chronic inflammation from disease and a reduced BMD.

Clinical Observations in Total Body DXA: Technical Aspects of Positioning and Analysis - Corrected Proof

Jessie Libber, Neil Binkley, Diane Krueger — 2012-02-10

Abstract: Total body (TB) dual-energy X-ray absorptiometry (DXA) can assess regional body composition, which may necessitate greater attention to patient positioning and analysis than required for whole body assessment. This report describes technical challenges experienced in performing TB DXA, explores the frequency with which autoanalysis inaccuracies occur, assesses their effect on regional body composition results, and describes a uniform clinical approach for TB DXA positioning and analysis. Patient positioning followed manufacturer recommendations with additional facility-imposed procedures. On visual inspection, it was apparent that automated analysis often did not meet manufacturer guidelines, thus requiring manual alteration. To explore the frequency with which manual adjustments were needed, and the impact on results, TB scans were obtained in 20 men and 20 women aged 18–93yr. The head line was altered in 98%, one or both shoulder lines in 93%, and the lateral hip boundary in 40%. Manual and automated TB analyses were highly correlated (r2=0.98–1.00). However, regional result correlation was less robust, that is, automated and manual appendicular lean mass differed by more than our least significant change in 33%. In conclusion, manual correction of automated TB DXA scan analysis is often needed. Such alterations do not affect TB measures but may affect regional body composition results.

Importance of Ethnic Base Standard References for the Diagnosis of Osteoporosis in Thai Women - Corrected Proof

2011-12-12

Abstract: Many studies demonstrated the importance of using ethnic-specific normal database in the diagnosis of osteoporosis (OP). Aims of this study were to assess diagnostic agreement, prevalence of OP, and diagnostic misclassification between Caucasian, Japanese, and Thai normal databases.The cross-sectional study of 3181 Thai women who had bone mineral density (BMD) measurement between January 2008 and December 2010 was performed. BMDs at lumbar spine (LS), femoral neck (FN), and total hip (TH) were derived to T-score by using Caucasian, Japanese, and Thai standard references. Kappa statistic was used to assess diagnostic agreement and misclassification.Diagnostic agreements between Caucasian and Thai reference databases were 0.39 for LS and 0.90 for FN. No statistical agreement was found in TH region (0.01, p value=0.264). Applying the Japanese reference, diagnostic agreements were 0.71 for LS, 0.76 for FN, and 0.94 for TH regions. Prevalence of OP in postmenopausal women was 64.1%, 37.7%, and 41.4% using Caucasian, Japanese, and Thai standard references. Percentage of misclassification was varied by menopausal status and reference database from 11.2% to 48.7%. When applying Japanese databases instead of Caucasian normal databases, overall diagnostic misclassification decreased from 35.1% to 16.1%.Choice of reference database has a significant effect on the diagnosis of low bone mass and OP. Japanese reference database has better diagnostic agreement with previously studied Thai reference database in 1999 than Caucasian reference database.Bone mineral density has been shown to be different in different ethnic groups. Importance of using the ethnic-specific reference database for T-score derivation in the diagnosis of osteoporosis instead of standard Caucasian and the National Health and Nutrition Examination Survey III reference databases has been reported in some countries.