Dual-energy X-ray Absorptiometry Densitometer Research Articles

Plasma Trans Fatty Acids Concentrations Are Inversely Related to Bone Mineral Density and This Appears to Be Independent of Inflammation

Objective To investigate the association between plasma trans fatty acids (TFAs) and bone mineral density (BMD) and risk of fracture among US adults. Furthermore, we have evaluated the impact of inflammation on this relationship. Methods Participants (the National Health and Nutrition Examination Survey) with measured data on BMD and TFAs were included. TFAs were measured by gas chromatography–mass spectrometry and BMD was measured using dual-energy x-ray absorptiometry densitometers. Results Of the 4022 eligible participants, 48.1% were men. The mean age of the population sample was 44.6 years. In the model adjusted for age, sex, race, education, income, physical activity, smoking, fasting blood glucose, systolic and diastolic blood pressure, body mass index, diabetes, and hypertension, across the increasing quartiles (Q) of individual plasma TFAs, BMD decreased for most of the sites measure: for example, Q1 vs. Q4 1.04 vs. 0.095 g/cm2 for palmitelaidic acid and 1.11 vs. 0.099 g/cm2 for elaidic acid (all p < 0.001). In models using the same adjustment, linear regression displayed a significant negative association between plasma TFAs and BMD for most of the sites measured (all p < 0.001). Moderation analysis revealed that inflammation [assessed as a serum C-reactive protein (CRP)] was not significantly implicated in the relationship between BMD and TFAs. There was no significant difference in percentage of fractures (hip, spine, wrist) observed across quartiles of plasma TFAs (all p > 0.125). Conclusions Our findings highlight, for the first time, the potentially detrimental impact of plasma TFAs on bone health that does not appear to be moderated through inflammation.

Prescreening for osteoporosis with forearm bone densitometry in health examination population

BackgroundEarly detection and timely prophylaxis can retard the progression of osteoporosis. The purpose of this study was to determine the validity of peripheral Dual Energy X-ray Absorptiometry (DXA) test for osteoporosis screening. We examined peripheral bone mineral density (BMD) using AKDX-09 W-I DXA densitometer. Firstly, we acquired BMD data from manufacturer-supplied density-gradient phantoms and 30 volunteers to investigate its accuracy and precision, then we measured BMD for 150 volunteers using both AKDX (left forearm) and Hologic Discovery Wi (left forearm, left hip and L1 - L4 vertebrae) simultaneously. Correlation relationship of BMD results acquired from two instruments was assessed by simple linear regression analysis, the Receiver Operating Characteristic (ROC) curves and Areas Under the Curves (AUCs) were evaluated for the diagnostic value of left forearm BMD measured by AKDX in detecting osteoporosis.ResultsIn vitro precision errors of AKDX BMD were 0.40, 0.20, 0.19%, respectively, on low-, medium-, and high-density phantom; in vivo precision was 1.65%. Positive correlation was observed between BMD measured by AKDX and Hologic at the forearm (r = 0.670), L1–L4 (r = 0.430, femoral neck (r = 0.449), and total hip (r = 0.559). With Hologic measured T-score as the gold standard, the sensitivity of AKDX T-score < − 1 for identifying suboptimal bone health was 63.0 and 76.1%, respectively, at the distal one-third radius and at any site, and the specificity was 73.9 and 90.0%, respectively; the AUCs were 0.708 and 0.879. The sensitivity of AKDX T-score ≤ − 2.5 for identifying osteoporosis at the distal one-third radius and at any site was 76.9 and70.4%, respectively, and the specificity was 80.4 and 78.0%, respectively; the AUCs were 0.823 and 0.778.ConclusionsPeripheral DXA appears to be a reliable tool for prescreening for osteoporosis.

Association between geriatric nutrition risk index and bone mineral density in elderly Chinese people.

To evaluate the relationship between geriatric nutrition risk index (GNRI) and bone mineral density (BMD) in elderly Chinese people. We recruited 1130 older adults (60-89 years old) between May 2018 and December 2019. Participants underwent clinical, laboratory, and densitometry examinations. Dual-energy x-ray absorptiometry densitometers and corresponding software were used to assess the BMD and T-scores of participants. Differences between study groups were assessed using one-way analysis of variance (ANOVA) for continuous variables and the chi-square test for categorical variables. Pearson's correlation coefficient was used to assess the correlation between two variables. Multivariate linear regressions with or without adjustments were constructed to explore the possible confounding variables. Individuals with higher GNRI values had higher total hip and lumbar spine T-scores (P < 0.001, P = 0.029, respectively). Pearson's correlation demonstrated that GNRIs were positively correlated with BMD at different anatomical sites, in both sexes but especially in women. A multiple regression demonstrated that GNRIs were independently associated with total hip T-score in both sexes (β = 0.111 for men and 0.174 for women; P = 0.034 and 0.008, respectively). Elderly people with higher GNRI values had higher total hip and lumbar spine T-scores, which suggested that GNRI is closely related to BMD. This relationship is maintained at the total hip, even after fully adjusting for possible confounding variables, and consequently, it may be a good indicator for identifying older people who need further bone health nutritional support.

Comparison of Differences in Bone Mineral Density Measurement With 3 Hologic Dual-Energy X-Ray Absorptiometry Scan Modes

Bone mineral density (BMD) measurement using dual-energy X-ray absorptiometry (DXA) is considered a diagnostic parameter for osteoporosis by the World Health Organization (WHO). DXA densitometers have different scanning modes for BMD measurements, although the specific scanning modes vary based upon the manufacturer. For DXA machines manufactured by Hologic, which are used globally, a range of scanning modes exist, including but not limited to (in order of decreasing spatial resolution) Array, Fast Array, and Express Array. Only a handful of prior studies have compared the reproducibility of BMD measurements across scan modes. The present study aimed to add to this body of literature by investigating the differences in BMD measured between 3 scanning modes in Hologic DXA machines at 19 different health centers. As part of cross-calibration activities for two multi-center studies in China measuring BMD, the European spine phantom (ESP, 1.000 g/cm2) was scanned on 19 different Hologic DXA machines. To measure differences in BMD between the 3 scan modes most commonly found on the Hologic models available (i.e., Array, Fast Array, Express Array), the ESP measurement was performed 10 times for each scan mode on each Hologic DXA machine. One-sample t test was used to compare the average difference between the measured ESP results of the 3 scanning modes at each hospital and reference ESP values. Single factor analysis of variance was performed to compare the average differences between the pairs of scanning modes using the reference ESP. Statistically significant differences between the measured ESP results with reference ESP values were found with each scanning mode at 19 hospitals (all p values <0.05). Consistent with this finding, differences in average BMD between the Array mode and Fast Array mode were invariably the smallest compared to differences seen between the other two pairs of scan modes. Significant differences were observed between average ESP BMD for the Array and Express Array scan modes (0.971 ± 0.013 vs 0.935 ± 0.027, p < 0.001), and between Fast Array and Express Array scan modes (0.972 ± 0.012 vs 0.935 ± 0.027, p < 0.001). However, no significant difference in average ESP BMD was observed between the Array and Fast Array scan modes (0.971 ± 0.013 vs 0.972 ± 0.012, p = 0.997). The selection of ideal scanning mode requires a balance of scanning time, radiation exposure, and measurement accuracy. In this ex vivo study, the Fast Array scanning mode appeared to be a reasonable choice compared with Array and Express Array for BMD measurements by Hologic DXA. Future in vivo studies can help guide the clinical application of these findings.

Urban-Rural Differences in Bone Mineral Density and its Association with Reproductive and Menstrual Factors Among Older Women.

This study aimed to compare the bone mineral density (BMD) of older women living in rural and urban areas, and evaluate the potential factors affecting the risk of osteoporosis. We recruited 574 women aged 65years or older from rural areas and 496 from urban areas in Shanghai, China. The BMD values of the lumbar vertebrae and total left hip were measured by a dual energy X-ray absorptiometry densitometer. We also recorded information about education level, family income, medications, reproductive and menstrual history, diet, smoking, and alcohol consumption. Women in urban areas had significantly higher BMD in their lumbar spine, and there was a dramatic increase in the proportion of women with osteoporosis in rural areas. The age at menarche was significantly higher among women living in rural areas, and there were more years from menarche to menopause among urban women. Rural women had significantly higher numbers of both pregnancies and parity, and a significantly lower age at first parity. In multiple linear regression analyses, years from menarche to menopause was independently related to high lumbar spine BMD, while age at menarche and parity was independently related to low lumbar spine BMD. More older women in rural areas had osteoporosis. Later menarche, less years from menarche to menopause and higher parity might partially contribute to decreased BMD among women in rural areas. More attention should be paid to women in rural areas to prevent bone loss and further bone and health impairment.

Effect of Hormone Replacement Therapy on Bone Mineral Density and Body Composition in Chinese Adolescent and Young Adult Turner Syndrome Patients.

A longitudinal observational study was performed comparing BMD and body composition in Turner syndrome girls before and after 1 year of HRT treatment. Whole body BMD, femur neck BMD, total hip BMD, and lean mass were significantly increased, but there was no difference in fat mass, and lumbar spine BMD.Purpose: Low bone mineral density (BMD) is one of the major health problems in Turner syndrome (TS) patients, and a certain percentage of TS girls are treated with hormone replacement therapy (HRT) to improve their BMD, among other health benefits. While it is generally accepted that HRT improves BMD and body composition in adolescent and young adult TS patients, studies of HRT in Chinese TS patients are limited.Methods: To investigate the effects of HRT in Chinese TS girls, we performed a longitudinal observational study which compared measurement of BMD and body composition by dual energy X-ray absorptiometry (DXA) using a Lunar DXA densitometer in 20 Chinese adolescent and young adult TS patients (average age = 18) before and after 1 year of HRT treatment.Results: Whole body BMD (0.85 vs. 0.87 g/cm2, P < 0.001), femur neck BMD (0.6 vs. 0.62 g/cm2, P = 0.02), total hip BMD (0.68 vs. 0.71 g/cm2, P = 0.003) and whole body lean mass (30.39 vs. 31.66 kg, P = 0.002) were significantly increased in these patients after 1 year HRT treatment, but there was no difference in whole body fat mass, android:gynoid ratio and lumbar spine BMD.Conclusions: In summary, our study found that HRT was an effective way to increase whole body BMD, femur neck BMD, total hip BMD and whole body lean mass in Chinese TS girls, with no effect on whole body fat mass, android:gynoid ratio or lumbar spine BMD.

Osteoporosis and Osteopenia Among Patients With Type 2 Diabetes Aged ≥50: Role of Sex and Clinical Characteristics

Introduction/Background: Although some studies have explored the association of adiposity and life habits (such as smoking) with osteoporosis and osteopenia among type 2 diabetes mellitus (T2DM) patients, the association between diabetic clinical characteristics (especially hypoglycemic drug use) and osteoporosis/osteopenia remains unclear. This study aimed to investigate the relationship of clinical characteristics with osteoporosis and osteopenia among T2DM patients by sex. Methods: A total of 1222 T2DM patients aged ≥50 were included in the present study. Information on demographic, anthropometric and clinical characteristics was collected from medical records. Bone mineral density was assessed by dual-energy X-ray absorptiometry densitometer. Multiple adjusted logistic regression analyses were performed to estimate the odds ratio (OR) and 95% confidence interval (CI) of osteoporosis and osteopenia related to clinical characteristics. Results: Of all participants, the prevalence of osteoporosis and osteopenia was 9.2% and 41.3%, respectively, and they were higher in females (14.7% and 48.5%) than in males (2.8% and 33%). After adjustment for potential confounders, the results showed that overweight (OR = 0.59; 95% CI, 0.42–0.81) and obesity (OR = 0.35; 95% CI, 0.24–0.50) were related to decreased odds of osteoporosis and osteopenia in both male and female T2DM patients, poor glycemic control (OR = 1.63; 95% CI, 1.08–2.47) was associated with increased odds of osteoporosis and osteopenia in males, and metformin treatment (OR = 0.65; 95% CI, 0.43–0.99) was associated with decreased odds of osteoporosis and osteopenia in females. Conclusions: Better glycemic management and rational choice of antidiabetic medication might be promising to prevent osteoporosis in T2DM patients. Further longitudinal studies are warranted to explore the association between antidiabetic treatment and osteoporosis.

The association between dietary inflammatory properties and bone mineral density and risk of fracture in US adults.

To examine the associations of dietary inflammatory index (DII) with bone mineral density (BMD) and fracture risk in adult Americans.Subjects/Method:The United States National Health and Nutrition Examination Survey participants during 2005-2010 were included if they had measured data on dietary intake and BMD. DII scores were calculated from estimated micro- and macronutrients from a single 24-h dietary recall. BMD was measured using dual-energy X-ray absorptiometry densitometers. Risk of fractures was obtained from participant self-report (ever) based on doctor information. Analyze of covariance and χ2-tests were employed, while accounting for the complex survey design. A total of 18 318 participants were included, with 51.3% (9397) being men. Age, sex, race, physical activity, smoking, C-reactive protein and body mass index-adjusted mean BMD (g/cm2) in different bodily sites significantly decreased across increasing quarters of the DII (all P<0.001). After further adjustment for calcium intake, the trend in BMD across DII quarters remained significant for total femur, femoral neck, trochanter and intertrochanter BMD (all P<0.001). Across increasing quarters of the DII, the proportion of fractures ranged from 1.1 to 1.5% for hip fracture (P=0.02), from 7.9 to 10.5% for wrist fracture (P<0.001) and from 2.2 to 2.7% for spine fracture (P=0.002. Prevalent wrist fractures significantly differed across DII quarters (P<0.0001), driven by high prevalence in the top quarter, while hip and spine fractures' prevalence did not vary significantly. The current study provides evidence suggesting a potential adverse effect of pro-inflammatory diet on bone health; which may have implications for dietary approaches for those with history of abnormal bone health complications.

Densitometer-Specific Differences in the Correlation Between Body Mass Index and Lumbar Spine Trabecular Bone Score

Trabecular bone score (TBS) is a gray-level texture measure derived from lumbar spine dual-energy X-ray absorptiometry (DXA) images that predicts fractures independent of bone mineral density (BMD). Increased abdominal soft tissue in individuals with elevated body mass index (BMI) absorbs more X-rays during image acquisition for BMD measurement and must be accommodated by the TBS algorithm. We aimed to determine if the relationship between BMI and TBS varied between 2 major manufacturers' densitometers, because different densitometers accommodate soft tissues differently. We identified 1919 women and 811 men, participants of the Canadian Multicentre Osteoporosis Study, aged ≥40 yr with lumbar spine DXA scans acquired on GE Lunar (4 centers) or Hologic (3 centers) densitometers at year 10 of follow-up. TBS was calculated for L1–L4 (TBS iNsight® software, version 2.1). A significant negative correlation between TBS and BMI was observed when TBS measurements were performed on Hologic densitometers in men (Pearson r = −0.36, p < 0.0001) and in women (Pearson r = −0.33, p < 0.0001); significant correlations were not seen when TBS was measured on GE Lunar densitometers (Pearson r = 0.00 in men, Pearson r = −0.02 in women). Age-adjusted linear regression models confirmed significant interactions between BMI and densitometer manufacturer for both men and women (p < 0.0001). In contrast, comparable positive correlations were observed between BMD and BMI on both Hologic and GE Lunar densitometers in men and women. In conclusion, BMI significantly affects TBS values in men and women when measured on Hologic but not GE Lunar densitometers. This finding has implications for clinical and research applications of TBS, especially when TBS is measured sequentially on DXA densitometers from different manufacturers or when results from different machines are pooled for analysis.

Does Visceral Fat Estimated by Dual-Energy X-ray Absorptiometry Independently Predict Cardiometabolic Risks in Adults?

Abdominal visceral fat, typically measured by computer tomography (CT) or magnetic resonance imaging (MRI), has been shown to correlate with cardiometabolic risks. The purpose of this study was to examine whether a newly developed and validated visceral fat measurement from dual-energy X-ray absorptiometry (DXA) provides added predictive value to the cross-sectional differences of cardiometabolic parameters beyond the traditional anthropometric and DXA adiposity parameters. A heterogeneous cohort of 194 adults (81 males and 113 females) with a BMI of 19 to 54 kg/m(2) participated in this cross-sectional study. Body composition was measured with a DXA densitometer. Visceral fat was then computed with a proprietary algorithm. Insulin sensitivity index (SI, measured by intravenous glucose tolerance test), blood pressures, and lipid profiles, and peak oxygen uptake were also measured as cardiometabolic risk parameters. DXA-estimated visceral fat mass was associated with HDL cholesterol (regression coefficient [β] = -5.15, P < .01, adjusted R(2) = .21), triglyceride (β = 26.01, P < .01, adjusted R(2) = .14), and peak oxygen uptake (β = -3.15, P < .01, adjusted R(2) = .57) after adjusting for age, gender, and ethnicity. A subanalysis stratifying gender-specific BMI tertiles showed visceral fat, together with ethnicity, was independently associated with SI in overweight men and moderately obese women (second tertile). Without requiring additional CT or MRI-based measurements, visceral fat detected by DXA might offer certain advantages over the traditional DXA adiposity parameters as means of assessing cardiometabolic risks.

Riesgo relativo de osteoporosis según la densidad mineral ósea en mujeres menopáusicas sanas de la región occidental de Cuba

Introduction The highest specificity in the measurement of the magnitude of relative risk of osteoporosis and bone fracture among women is obtained when autochthonous ranges of bone mineral density (BMD), obtained from a normal population, are taken as reference values. These ranges are not sufficiently well established in Latin America. Objectives To characterize changes in bone mass according to absorptiometry measurements and the relative risk of osteoporosis in a selected female population (healthy, working women aged more than 49 years old) using BMD risk margins in an autochthonous population as reference values. Materials and methods We performed a cross-sectional survey in the western region of Cuba in 307 healthy women, aged 50 to 59 years old, from 1998 to 2007. BMD was measured with a dual-energy X-ray absorptiometry densitometer (DEXA Lunar) in the lumbar spine (anterior-posterior), femoral neck, Ward triangle, trochanter and whole body. Bone density (g/cm 2) was obtained and was also expressed as a quotient according to height for each skeletal site (g/m). The percent decrease in bone mass and the frequency of women at relative risk of fracture were calculated. Distributions in percentiles were determined and means and standard deviation were calculated according to ethnic origin. Differences in BMD according to length of amenorrhea, ethnic origin, quotients according to height, and results taking the World Health Organization criteria as reference (safety margins ≤1 standard deviation and risk ≤ 2.5 standard deviation) were evaluated in a young Cuban population and in other reference populations by means of analysis of variance (ANOVA) and Student’s t test for independent samples. Data were processed by SPSS, version 11.5 for Windows. Results In the average woman with less than 5 years of amenorrhea, the femur / height quotient, showed a decrease of 7.7 % when compared with peak bone mass in the young population. The frequency of women at risk of fracture increased for fractures of the lumbar spine and femoral neck when the Cuban population was used as reference. According to the risk margin (g/cm 2), in the population aged between 50 and 59 years, not differentiated by ethnic origin, the relative risk of fracture of the femoral neck was 4.4 %, that for fracture of the lumbar vertebra was 8.1 % and that for whole-body fracture was 7.7 %. When the Cuban reference was applied for whole body fracture, the presence of risks was similar to the DEXA Lunar criteria. Conclusions The prevalence of risk of osteoporosis and decline in bone mass were determined in the study group. Our results provide further evidence of the highest specificity in skeletal sites when measurements are adjusted by height, using the criteria of risk margins in the autochthonous population as a reference.

Effects of the sample size of reference population on determining BMD reference curve and peak BMD and diagnosing osteoporosis

Establishing reference databases generally requires a large sample size to achieve reliable results. Our study revealed that the varying sample size from hundreds to thousands of individuals has no decisive effect on the bone mineral density (BMD) reference curve, peak BMD, and diagnosing osteoporosis. It provides a reference point for determining the sample size while establishing local BMD reference databases. This study attempts to determine a suitable sample size for establishing bone mineral density (BMD) reference databases in a local laboratory. The total reference population consisted of 3,662 Chinese females aged 6-85 years. BMDs were measured with a dual-energy X-ray absorptiometry densitometer. The subjects were randomly divided into four different sample groups, that is, total number (Tn) = 3,662, 1/2n = 1,831, 1/4n = 916, and 1/8n = 458. We used the best regression model to determine BMD reference curve and peak BMD. There was no significant difference in the full curves between the four sample groups at each skeletal site, although some discrepancy at the end of the curves was observed at the spine. Peak BMDs were very similar in the four sample groups. According to the Chinese diagnostic criteria (BMD >25% below the peak BMD as osteoporosis), no difference was observed in the osteoporosis detection rate using the reference values determined by the four different sample groups. Varying the sample size from hundreds to thousands has no decisive effect on establishing BMD reference curve and determining peak BMD. It should be practical for determining the reference population while establishing local BMD databases.

Normal Reference for Bone Density in Healthy Chinese Children

An ethnicity- and gender-specific normal reference database is necessary for the clinical dual-energy X-ray absorptiometry (DXA) assessment of skeletal status in Chinese children. We used a Lunar Prodigy DXA densitometer to measure bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) at total body and subcranial skeleton for 877 healthy Chinese children (505 boys, 372 girls) aged 5–13 yr. The height-for-age, BA-for-height, and BMC-for-BA percentile curves were developed using the LMS method ( L, power in Box-Cox transformation; M, median; S, coefficient of variation). We found that total body BMD and subcranial skeleton BMD were highly correlated ( r = 0.701–0.949), and that total body BMD was significantly higher than subcranial skeleton BMD for each gender and age group ( p < 0.001). No gender differences in total body and subcranial skeleton BMD were found. Total body lean mass correlated highly with total body BMC and subcranial skeleton BMD and BMC (boys: r = 0.888–0.953, girls: r = 0.917–0.967) and moderately with total body BMD (boys: r = 0.684, girls: r = 0.777). The head region accounted for 16–52% and 16–49% of the total body BMC in boys and girls, respectively, and the percentages were negatively correlated with age (boys: r = −0.824, girls: r = −0.864) and height (boys: r = −0.911, girls: r = −0.922). Regression analyses showed that age explained more variance in subcranial skeleton BMD (boys: R 2 = 0.641, girls: R 2 = 0.685) than in total body BMD (boys: R 2 = 0.387, girls: R 2 = 0.472). In summary, we have presented an ethnicity- and gender-specific densitometric normal reference database for Chinese children aged 5–13 yr. It should allow for an appropriate clinical assessment of total body bone density in Chinese children as measured by the Lunar Prodigy DXA densitometer.

European semi-anthropomorphic spine phantom for the calibration of bone densitometers: assessment of precision, stability and accuracy. The European Quantitation of Osteoporosis Study Group.

Up to now it has not been possible to reliably cross-calibrate dual-energy X-ray absorptiometry (DXA) densitometry equipment made by different manufacturers so that a measurement made on an individual subject can be expressed in the units used with a different type of machine. Manufacturers have adopted various procedures for edge detection and calibration, producing various normal ranges which are specific to each individual manufacturer's brand of machine. In this study we have used the recently described European Spine Phantom (ESP, prototype version), which contains three semi-anthropomorphic "vertebrae" of different densities made of stimulated cortical and trabecular bone, to calibrate a range of DXA densitometers and quantitative computed tomography (QCT) equipment used in the measurement of trabecular bone density of the lumbar vertebrae. Three brands of QCT equipment and three brands of DXA equipment were assessed. Repeat measurements were made to assess machine stability. With the large majority of machines which proved stable, mean values were obtained for the measured low, medium and high density vertebrae respectively. In the case of the QCT equipment these means were for the trabecular bone density, and in the case of the DXA equipment for vertebral body bone density in the posteroanterior projection. All DXA machines overestimated the projected area of the vertebral bodies by incorporating variable amounts of transverse process. In general, the QCT equipment gave measured values which were close to the specified values for trabecular density, but there were substantial differences from the specified values in the results provided by the three DXA brands. For the QCT and Norland DXA machines (posteroanterior view), the relationships between specified densities and observed densities were found to be linear, whereas for the other DXA equipment (posteroanterior view), slightly curvilinear, exponential fits were found to be necessary to fit the plots of observed versus specified densities. From these plots, individual calibration equations were derived for each machine studied. For optimal cross-calibration, it was found to be necessary to use an individual calibration equation for each machine. This study has shown that it is possible to cross-calibrate DXA as well as QCT equipment for the measurement of axial bone density. This will be of considerable benefit for large-scale epidemiological studies as well as for multi-site clinical studies depending on bone densitometry.