Dual-energy X-ray Absorptiometry Device Research Articles

Synthetic phantoms enable calibration between abattoir based dual energy X-ray absorptiometers used for prediction of lamb carcass composition

Dual energy x-ray absorptiometry (DXA) devices were installed at two Australian abattoirs to predict computed tomography (CT) determined fat % and lean % of lamb carcasses. This study tested three algorithms developed for these devices, termed β1, β2 and β3, and assessed their accuracy and precision in predicting CT composition. Algorithm β3 included the use of a plastic phantom calibration block scanned by both DXA devices to adjust prediction equations, resulting in superior accuracy to the algorithms without phantom calibration (β1 and β2). When compared to the gold-standard CT composition, the bias of the DXA predictions was lowest when using algorithm β3 at the two sites (−1.17%, −0.49% for fat %, 0.11%, −0.37% for lean %). The difference of DXA composition predictions between sites was lowest when using algorithm β3, which demonstrated between site differences of 0.59 CT fat %, and 0.46 CT lean%. In contrast, algorithm β1 and β2 produced differences of 23.7% and 30.8% for CT fat, and 17.3% and 21.9% for CT lean between the two DXA devices. There was a small difference of 0.78% between the fat predictions of the first DXA image compared to the second DXA image for each carcass. The precision of predictions improved slightly using algorithm β3. This work demonstrates that the in-line DXA systems can produce comparable results across sites.

New point-of-care calcaneal ultrasound densitometer (Osteosys BeeTLE) compared to standard dual-energy X-ray absorptiometry (DXA)

Dual-energy X-ray absorptiometry (DXA) represents the gold standard for measuring bone mineral density (BMD). However, its size and bulkiness limit its use in mass screening. Portable and easily accessible instruments are more suitable for this purpose. We conducted a study to assess the repeatability, sensitivity, accuracy, and validation of a new ultrasound densitometer for the calcaneus (OsteoSys BeeTLe) compared to standard DXA. BMD (g/cm2) was measured at the femoral and lumbar spine levels using DXA (Discovery Acclaim (Hologic, Waltham, MA, USA) or Lunar Prodigy (GE Healthcare, Madison, WI, USA) devices). Bone Quality Index (BQI, a dimensionless measure of bone quality derived from measures of SOS [Speed Of Sound] and BUA [broadband ultrasound attenuation]) was measured with OsteoSys BeeTLe. The Bland–Altman test and simple linear regression were used to evaluate the association between values measured with the two instruments. Additionally, the ability of the T-score calculated with BeeTLe to identify patients with previous osteoporotic fractures was tested using ROC curves. A total of 201 patients (94.5% females) with a mean age of 62.1 ± 10.2 were included in the study. The BeeTLe instrument showed a coefficient of variation (CV, in 75 repeated measurements) of 1.21%, which was not statistically different from the CV of DXA (1.20%). We found a significant association between BQI and BMD at the femoral neck (r2 = 0.500, p < 0.0001), total femur (r2 = 0.545, p < 0.0001), and lumbar spine (r2 = 0.455, p < 0.0001). T-scores bias were 0.215 (SD 0.876), 0.021 (SD 0.889) and 0.523 (SD 0.092), for femoral neck, total hip and lumbar spine respectively. AUC for discriminating fracture and non-fractured patients were not significantly different with OsteoSys BeeTLe and standard DXA. In this preliminary study, BeeTLe, a new point-of-care ultrasound densitometer, demonstrated good repeatability and performance similar to DXA. Therefore, its use can be proposed in screening for osteoporosis.

Unexpected early loosening of rectangular straight femoral Zweymüller stems with an alumina-reduced surface after total hip arthroplasty—a prospective, double-blind, randomized controlled trial

BackgroundAlumina particles from the grit blasting of Ti-alloy stems are suspected to contribute to aseptic loosening. An alumina-reduced stem surface was hypothesized to improve osseointegration and show comparable short-term outcomes to those of a standard stem.MethodsIn this prospective, double-blind, randomized trial, 26 standard (STD) and 27 experimental new technology (NT) stems were implanted. The latter were additionally treated by acid etching and ice blasting to remove alumina particles from the grit-blasting process. Follow-up occurred at 12 and 24 months. Bone mineral density (BMD) around the stem was measured by a dual-energy x-ray absorptiometry device (DEXA). Radiographs were reviewed for alterations. Clinical scoring comprised the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Harris Hip Score (HHS). Survival rates were calculated up to 50 months.ResultsLower mean BMD and more severe cortical hypertrophies were found in the NT group. At 12 months, radiolucent lines were observed mostly in the metaphyseal zone for both groups, with a progression tendency in the NT group at 24 months. At 12 months, pain scores and the WOMAC total and physical activity scores were significantly lower in the NT group, without any differences thereafter. The number of NT stem revisions amounted to 6 (24%) and 11 (41%) at 24 and 50 months, respectively.ConclusionIn the NT group, unexpected catastrophic failure rates of 41% caused by early aseptic loosening were noted within 50 months. Compared with the STD stems, NT stems lead to poor clinical and radiographic results.Level of evidence: II.Trial Registration: NCT05053048.

An Energy-Reduced Mediterranean Diet, Physical Activity, and Body Composition: An Interim Subgroup Analysis of the PREDIMED-Plus Randomized Clinical Trial.

Strategies targeting body composition may help prevent chronic diseases in persons with excess weight, but randomized clinical trials evaluating lifestyle interventions have rarely reported effects on directly quantified body composition. To evaluate the effects of a lifestyle weight-loss intervention on changes in overall and regional body composition. The ongoing Prevención con Dieta Mediterránea-Plus (PREDIMED-Plus) randomized clinical trial is designed to test the effect of the intervention on cardiovascular disease prevention after 8 years of follow-up. The trial is being conducted in 23 Spanish research centers and includes men and women (age 55-75 years) with body mass index between 27 and 40 and metabolic syndrome. The trial reported herein is an interim subgroup analysis of the intermediate outcome body composition after 3-year follow-up, and data analysis was conducted from February 1 to November 30, 2022. Of 6874 total PREDIMED-Plus participants, a subsample of 1521 individuals, coming from centers with access to a dual energy x-ray absorptiometry device, underwent body composition measurements at 3 time points. Participants were randomly allocated to a multifactorial intervention based on an energy-reduced Mediterranean diet (MedDiet) and increased physical activity (PA) or to a control group based on usual care, with advice to follow an ad libitum MedDiet, but no physical activity promotion. The outcomes (continuous) were 3-year changes in total fat and lean mass (expressed as percentages of body mass) and visceral fat (in grams), tested using multivariable linear mixed-effects models. Clinical relevance of changes in body components (dichotomous) was assessed based on 5% or more improvements in baseline values, using logistic regression. Main analyses were performed in the evaluable population (completers only) and in sensitivity analyses, multiple imputation was performed to include data of participants lost to follow-up (intention-to-treat analyses). A total of 1521 individuals were included (mean [SD] age, 65.3 [5.0] years; 52.1% men). In comparison with the control group (n=761), participants in the intervention arm (n=760) showed greater reductions in the percentage of total fat (between group differences after 1-year, -0.94% [95% CI, -1.19 to -0.69]; 3 years, -0.38% [95% CI, -0.64 to -0.12] and visceral fat storage after 1 year, -126 g [95% CI, -179 to -73.3 g]; 3 years, -70.4 g [95% CI, -126 to -15.2 g] and greater increases in the percentage of total lean mass at 1 year, 0.88% [95% CI, 0.63%-1.12%]; 3-years 0.34% [95% CI, 0.09%-0.60%]). The intervention group was more likely to show improvements of 5% or more in baseline body components (absolute risk reduction after 1 year, 13% for total fat mass, 11% for total lean mass, and 14% for visceral fat mass; after 3-years: 6% for total fat mass, 6% for total lean mass, and 8% for visceral fat mass). The number of participants needed to treat was between 12 and 17 to attain at least 1 individual with possibly clinically meaningful improvements in body composition. The findings of this trial suggest a weight-loss lifestyle intervention based on an energy-reduced MedDiet and physical activity significantly reduced total and visceral fat and attenuated age-related losses of lean mass in older adults with overweight or obesity and metabolic syndrome. Continued follow-up is warranted to confirm the long-term consequences of these changes on cardiovascular clinical end points. isrctn.org Identifier: ISRCTN89898870.

Small animal DXA instrument comparison and validation

Several new peripheral dual-energy X-ray absorptiometry (DXA) devices designed for assessment of bone and body composition in rodents have been developed. We compared the performance (accuracy and precision) of two of these devices, the InAlyzer and the iNSiGHT, to those of an established device, the PIXImus. We measured total body bone mineral content (BMC), bone mineral density (BMD), and body composition (lean and fat mass) on the three DXA devices in 18 male C57Bl/6 J mice (6 each of ages 8, 14, and 24 weeks, weighing 22 to 33 g). DXA body composition measures were compared to whole-body nuclear magnetic resonance (NMR) outcomes. BMC of the femur was also compared to ex vivo micro-computed tomography (microCT). Total body BMD from the InAlyzer and iNSiGHT devices was strongly correlated to that from PIXImus (R2 = 0.83 and 0.82, respectively), but was ~25 % higher than PIXImus. Total body BMC measures by InAlyzer were strongly associated with those from PIXImus (R2 = 0.86), whereas those from iNSiGHT were only weakly correlated (R2 = 0.29). Femur BMC from InAlyzer was strongly correlated with microCT outcomes, whereas iNSiGHT was only weakly correlated. InAlyzer and iNSiGHT fat mass measures were very strongly correlated with PIXImus and NMR outcomes (R2 = 0.91 to 0.97), with slightly weaker associations for lean mass (R2 = 0.81 to 0.76). Short-term precision of InAlyzer and iNSiGHT measurements were excellent, and akin to those from the PIXImus for both body composition and bone measures, ranging between 0.39 and 3.2 %. With faster scan times, closed X-ray source and excellent precision, the new devices are both satisfactory replacements for the now discontinued PIXImus system. However, given the accuracy of the bone and body composition measures, the InAlyzer may be preferable for studies where musculoskeletal changes are the main interest.

Relationship Between Blood Monocyte-HDL Ratio and Carotid Intima Media Thickness in with Postmenopausal Women

Introduction/Background: The monocyte-to-high-density lipoprotein (HDL) ratio (MHR) and carotid intima media thickness may be used as a marker of inflammation and oxidative stres. This study is aimed to investigate the role of MHR in etiopathogenesis and to determine the association between MHR and carotid intima media thickness, fracture risk, and quality of life (QoL) in postmenopausal osteoporosis patients without comorbidities. Methodology: Sixty osteoporosis, sixty osteopenia and sixty control groups were included in the prospective study evaluating postmenapausal women. The monocyte, HDL, and MHR values of all patients were evaluated. The bone mineral density of the participants was determined using the dual energy X-ray absorptiometry device. The fracture risk was assessed using the Turkish model of the Fracture Risk Assessment Tool. The QoL was determined using the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) scale, and carotid intima media thickness ultrasonography was used. Results: The age, body mass index, duration of menopause, monocyte, HDL, and MHR were similar in all three groups. carotid intima media thickness was higher in the osteoporosis group than in the normal group (p=0.015). A positive correlation was found between L1-4 total T score and monocytes, major osteoporotic fracture risk and physical function from QUALEFFO-41 sub-headings, MHR and QUALEFFO-41 total score (p<0.05). When all participants were evaluated, a positive correlation was found between femoral neck T score and MHR, L1-4 total T score and monocytes, while a negative correlation was found between L1-4 total T score and CIMT (p<0.05). Conclusion: Among postmenopausal women without comorbidities, MHR in the osteoporosis group was similar to that of the osteopenia and normal groups. Monocyte and MHR correlate with femoral neck T score and L1-4 total T score. CIMT was associated with a decreased L1–4 total T-score and an increased fracture risk, but not with MHR.

Evaluation of a Rapid Four-Compartment Model and Stand-Alone Methods in Hispanic Adults

BackgroundA rapid 4-compartment (4C) model integrates dual-energy x-ray absorptiometry (DXA) and multi-frequency bioimpedance analysis (MFBIA), which may be useful for clinical and research settings seeking to employ a multi-compartment model. ObjectivesThis study aimed to determine the added benefit of a rapid 4C model over stand-alone DXA and MFBIA when estimating body composition. MethodsOne hundred and thirty participants (n = 60 male; n = 70 female) of Hispanic descent were included in the present analysis. A criterion 4C model that employed air displacement plethysmography (body volume), deuterium oxide (total body water), and DXA (bone mineral) was used to measure fat mass (FM), fat-free mass (FFM), and body fat percent (%BF). A rapid 4C model (DXA-derived body volume and bone mineral; MFBIA-derived total body water) and stand-alone DXA (GE Lunar Prodigy) and MFBIA (InBody 570) assessments were compared against the criterion 4C model. ResultsLin’s concordance correlation coefficient values were >0.90 for all comparisons. The standard error of the estimates ranged from 1.3 to 2.0 kg, 1.6 to 2.2 kg, and 2.1 to 2.7% for FM, FFM, and %BF, respectively. The 95% limits of agreement ranged from ±3.0 to 4.2 kg, ±3.1 to 4.2 kg, and ±4.9 to 5.2% for FM, FFM, and %BF, respectively. ConclusionsResults revealed that all 3 methods provided acceptable body composition results. The MFBIA device used in the current study may be a more economically friendly option than DXA or when there is a need to minimize radiation exposure. Nonetheless, clinics and laboratories that already have a DXA device in place or that value having the lowest individual error when conducting a test may consider continuing to use the machine. Lastly, a rapid 4C model may be useful for assessing body composition measures observed in the current study and those provided by a multi-compartment model (e.g., protein).

Positive relation between dietary inflammatory index and osteoporosis in postmenopausal women.

Background: Previous studies have shown that some dietary components may be implicated in the aetiology of postmenopausal osteoporosis. Objective: We examined the relationship between Dietary Inflammatory Index (DII®) and osteoporosis in postmenopausal women. Study design: Eight hundred and fifty postmenopausal women aged 50-65 years were randomly selected from 87 health care centers. Bone mineral density (BMD) was measured using the anterior-posteriorlumbar spine (L1-L4) and proximal femur neck through Hologic QDR 4500W(S/N 50266) dual-energy X-ray absorptiometry device. After checking inclusion and exclusion criteria and diagnosis of osteoporosis, 124 women with normal bone mineral density (normal-BMD) and 108 women with osteoporosis were selected. Demographic, anthropometric, physical activity, midwifery, and dietary intake questionnaires were completed. DII was calculated based on a valid and reliable 168-item semi-quantitative food frequency questionnaire using 37 (out of 45) food parameters. A Logistic regression model adjusted for confounders was applied to estimate osteoporosis's odds ratio (OR) based on modeling DII as a continuous and dichotomous variable. Results: In this study, DII scores ranged from -3.71 (the most anti-inflammatory score) to +4.16 (the most pro-inflammatory score). The median DII value among the osteoporosis group was 0.97, among the normal group it was -0.31, indicating a more pro-inflammatory diet for osteoporosis. There were positive associations between osteoporosis and DII based on both continuous (Adjusted OR=3.467, 95% confidence interval (CI): 2.280-5.272, P-value<0.001) and dichotomous (Adjusted OR: DII ≤-0.31 / >-0.31=0.248, 95% CI: 0.110-0.561, P-value=0.001) measures in modeling adjusted for age, BMI, post-menopausal years, parity, education, total energy intake, and physical activity. Conclusions: These data suggest a pro-inflammatory diet, as indicated by increasing the DII score, may be a risk factor for osteoporosis in postmenopausal Iranian women.

Cross-calibration of two dual-energy X-ray absorptiometry devices for the measurement of body composition in young children

This study aimed to cross-calibrate body composition measures from the GE Lunar Prodigy and GE Lunar iDXA in a cohort of young children. 28 children (mean age 3.4 years) were measured on the iDXA followed by the Prodigy. Prodigy scans were subsequently reanalysed using enCORE v17 enhanced analysis (“Prodigy enhanced”). Body composition parameters were compared across three evaluation methods (Prodigy, Prodigy enhanced, iDXA), and adjustment equations were developed. There were differences in the three evaluation methods for all body composition parameters. Body fat percentage (%BF) from the iDXA was approximately 1.5-fold greater than the Prodigy, whereas bone mineral density (BMD) was approximately 20% lower. Reanalysis of Prodigy scans with enhanced software attenuated these differences (%BF: − 5.2% [95% CI − 3.5, − 6.8]; and BMD: 1.0% [95% CI 0.0, 1.9]), although significant differences remained for all parameters except total body less head (TBLH) total mass and TBLH BMD, and some regional estimates. There were large differences between the Prodigy and iDXA, with these differences related both to scan resolution and software. Reanalysis of Prodigy scans with enhanced analysis resulted in body composition values much closer to those obtained on the iDXA, although differences remained. As manufacturers update models and software, researchers and clinicians need to be aware of the impact this may have on the longitudinal assessment of body composition, as results may not be comparable across devices and software versions.

A Comparative and Sex-Specific Study of Bio-Electrical Impedance Analysis and Dual Energy X-ray Absorptiometry for Estimating Whole-Body and Segmental Body Composition in Healthy Young Adults

Bio-electrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) are methods to estimate human body composition. This study aimed to compare sex-specific outcomes for estimating segmental and whole-body composition in 83 healthy participants (21.9 ± 1.5 years, 56% men) using Inbody S10 BIA and Norland Elite DXA devices. One-way repeated measures ANOVAs showed significantly lower whole-body fat% and whole-body fat mass values alongside higher whole-body lean mass values resulting from BIA when compared to DXA (both sexes: p &lt; 0.001). In men, whole-body bone mineral content was significantly higher using BIA against DXA (p &lt; 0.001). Regardless of sex, no significant BIA versus DXA difference was found in arm fat mass (men: p = 0.180, women: p = 0.233), whereas significantly lower leg fat mass values were found with BIA versus DXA (both sexes: p &lt; 0.001). Additionally, significantly higher arm lean mass (both sexes: p &lt; 0.001) and leg lean mass (only women: p &lt; 0.001) were found in BIA versus DXA. Moderate to very strong positive associations (p &lt; 0.05) between BIA and DXA outcome measures were found, except for arm fat mass (men: p = 0.904, women: p = 0.130) and leg fat mass (only men: p = 0.845). This study highlights (sex-dependent) differences in corresponding test outcomes between BIA and DXA both at the segmental and whole-body level.

Diagnosis and Treatment of Osteoporosis, an Update Bibliographic Review

Introduction: Osteoporosis is a chronic, progressive skeletal disease characterized by low bone mineral density and deterioration of bone structure. There are multiple risk factors, both modifiable and non-modifiable. The main complication is fractures, which is why it must be diagnosed early and in a timely manner. Material and methods: Fourteen articles and one book on the diagnosis and treatment of osteoporosis were chosen in order to compare the best plan to follow in these patients in the different bibliographies reviewed. Discussion: The gold standard for diagnosing osteoporosis is the measurement of bone density with the dual energy X-ray absorptiometry device, using the T-score. The use of different biomarkers is useful both for early diagnosis and for monitoring the reaction to treatment, but it is necessary to take into account that the main objective is to prevent the disease and to improve the quality of life of the patients. On the other hand, the main and early treatment consists of physical activity adapted to each patient, diet rich in calcium, magnesium and vitamins that promote bone health, the pharmacological part of the treatment has different areas that depends on the situation of each patient, considering gender such as estrogens and progestogens in postmenopausal women, tolerance to drugs such as Denosumab, and in general, bisphosphonate is used as the first line of treatment due to the increase in bone mineral density that it produces, helping to prevent fractures and improving the quality of life of each patient. Conclusion: Osteoporosis is one of the diseases that can prevent the realization of basic activities, for this disease there are different methods of diagnosis and treatment, the main objective is to detect risk factors and make an early diagnosis to avoid complications that entails, relying on tools such as the FRAX calculator and the use of biomarkers, all this to reach the conclusion of the investigation, to use the different options and tools to provide appropriate treatment, this publication being an update on the options that are available today to treat this condition.

Effect of a Screening and Education Programme on Knowledge, Beliefs, and Practices Regarding Osteoporosis among Malaysians.

Background: Osteoporosis is an emerging geriatric condition with high morbidity and healthcare cost in developing nations experiencing rapid population ageing. Thus, identifying strategies to prevent osteoporosis is critical in safeguarding skeletal health. This study aimed to evaluate the effects of a bone health screening and education programme on knowledge, beliefs, and practice regarding osteoporosis among Malaysians aged 40 years and above. Methods: A longitudinal study was conducted from April 2018 to August 2019. During the first phase of the study, 400 Malaysians (190 men, 210 women) aged ≥ 40 years were recruited in Klang Valley, Malaysia. Information on subjects’ demography, medical history, knowledge, and beliefs regarding osteoporosis, physical activity status, and dietary and lifestyle practices were obtained. Subjects also underwent body anthropometry measurement and bone mineral density scan (hip and lumbar spine) using a dual-energy X-ray absorptiometry device. Six months after the first screening, similar investigations were carried out on the subjects. Results: During the follow-up session, 72 subjects were lost to follow up. Most of them were younger subjects with a lower awareness of healthy practices. A significant increase in knowledge, beliefs (p < 0.05), calcium supplement intake (p < 0.001), and dietary calcium intake (p = 0.036) and a reduction in coffee intake (p < 0.001) were found among subjects who attended the follow-up. In this study, the percentage of successful referrals was 41.86%. Subjects with osteoporosis were mostly prescribed alendronate plus vitamin D3 by medical doctors, and they followed the prescribed treatment accordingly. Conclusions: The bone health screening and education programmes in this study are effective in changing knowledge, beliefs, and practice regarding osteoporosis. The information is pertinent to policymakers in planning strategies to prevent osteoporosis and its associated problems among the middle-aged and elderly population in Malaysia. Nevertheless, a more comprehensive bone health education program that includes long-term monitoring and consultation is needed to halt the progression of bone loss.

MRI Based Validation of Abdominal Adipose Tissue Measurements From DXA in Postmenopausal Women

Visceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI. Participants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed. Participants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500. New software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.

Accuracy of predicting chemical body composition of growing pigs using dual-energy X-ray absorptiometry

Studies in animal science assessing nutrient and energy efficiency or determining nutrient requirements benefit from gathering exact measurements of body composition or body nutrient contents. Those are acquired by standardized dissection or by grinding the body followed by wet chemical analysis, respectively. The two methods do not result in the same type of information, but both are destructive. Harnessing human medical imaging techniques for animal science can enable repeated measurements of individuals over time and reduce the number of individuals required for research. Among imaging techniques, dual-energy X-ray absorptiometry (DXA) is particularly promising. However, the measurements obtained with DXA do not perfectly match dissections or chemical analyses, requiring the adjustment of the DXA via calibration equations. Several calibration regressions have been published, but comparative studies of those regression equations and whether they are applicable to different data sets are pending. Thus, it is currently not clear whether existing regression equations can be directly used to convert DXA measurements into chemical values or whether each individual DXA device will require its own calibration. Our study builds prediction equations that relate body composition to the content of single nutrients in growing entire male pigs (BW range 20–100 kg) as determined by both DXA and chemical analyses, with R2 ranging between 0.89 for ash and 0.99 for water and CP. Moreover, we show that the chemical composition of the empty body can be satisfactorily determined by DXA scans of carcasses, with the prediction error ranging between 4.3% for CP and 12.6% for ash. Finally, we compare existing prediction equations for pigs of a similar range of BWs with the equations derived from our DXA measurements and evaluate their fit with our chemical analysis data. We found that existing equations for absolute contents that were built using the same DXA beam technology predicted our data more precisely than equations based on different technologies and percentages of fat and lean mass. This indicates that the creation of generic regression equations that yield reliable estimates of body composition in pigs of different growth stages, sexes and genetic breeds could be achievable in the near future. DXA may be a promising tool for high-throughput phenotyping for genetic studies, because it efficiently measures body composition in a large number and wide array of animals.

Volume Reduction: Which Dose is Sufficient to Retain Resistance Training Adaptations in Older Women?

We compared the effects of different resistance training (RT) volume reduction strategies on muscular strength and lean soft-tissue (LST) in older women. Fifty-seven physically independent women (>60 years) performed a 20-week pre-conditioning phase of a standardized whole-body RT program (eight exercises, three sets, 8-12 repetitions, three sessions a week), and were then randomly assigned to one of the following conditions: reduced volume for a single set (RV1, n=20) or two sets (RV2, n=19), or maintained volume of three sets (MV, n=18) for 8 weeks (specific training phase). Muscular strength in the chest press, leg extension, and preacher curl exercises was determined by one-repetition maximum tests. A dual-energy X-ray absorptiometry device was used to estimate LST. An increase in muscular strength (16.3-32.1%) and LST (3.2-7.9%) was observed after the pre-conditioning phase. There was an increase in chest press for all groups (9.4-16.7%) after the specific training phase. In contrast, only MV increased significantly in the leg extension (4.4%). No between-group differences were revealed for LST in the specific training phase. Our results suggest that reduced RT volume from three to one set per exercise for 8 weeks seems sufficient to retain neuromuscular adaptations in older women.

MO054EFFICACY OF ORAL PHOSPHATE SUPPLEMENTATION IN CHILDREN WITH HEREDITARY HYPOPHOSPHATEMIC RICKETS WITH HYPERCALCIURIA

Abstract Background and Aims Hereditary hypophosphatemic rickets with hypercalciuria (HHRH; MIM #241530) is an autosomal recessive renal phosphate-wasting disorder caused by mutations in the SLC34A3/NPT2c gene. HHRH characterized by increased urinary phosphate excretion leading to hypophosphatemic rickets, short stature and elevated serum 1,25(OH)2D levels which result in hypercalciuria leads to nephrocalcinosis/urolithiasis due to enhanced intestinal calcium absorption and reduced PTH-dependent calcium reabsorption in the distal renal tubules. Treatment of HHRH involves administration of oral phosphate supplements alone to normalize of serum phosphate, alkaline phosphatase activity (ALP), PTH levels, urine calcium excretion for prevention of renal calcifications and progression of rickets. Currently there is no consensus on the optimal dose of oral phosphate in patients with HHRH. The aim of the study was to evaluate the efficacy of oral phosphate supplements in Russian cohort of children with HHRH. Method 9 children (7M/2F) with homozygous (n=6) and compound heterozygous (n=3) SLC34A3 mutations from unrelated families were examined. Treatment with oral phosphate supplements was started at the median age of patients 12.0 (IQR: 9.0; 13.0) years. The median dosage of oral phosphate supplements was 14.1 (IQR: 13.8; 14.8) mg/kg/day based on elemental phosphorus. The duration of follow-up was 36.0 (IQR: 16; 49) months. Blood electrolytes levels, ALP, PTH and 24-hour-urine excretion of calcium were evaluated in all children. ALP Z-scores were calculated using age- and sex-specific mean/standard deviation (SD) lab reference data. Bone mineral density with Z-score were measured in lumbar spine and whole body for all patients using a dual energy X-ray absorptiometry device. Molecular genetic analysis was performed in all children using by next generation sequencing. Results The median SD score of height at the first and last follow-up was -1.35 (IQR: -1.8; -0.87) and -1.51 (IQR: -2.0; -0.66) (p=0.6), respectively, short stature had 33.3% (3/9) of patients at first and 44.4% (4/9) at last follow-up (p=0.7). Treatment with low doses of oral phosphate supplements did not led to normalization of serum phosphorus:1.05 (IQR: 0.97; 1.39) vs. 0.93 (IQR: 0.81; 1.27) mmol/l (p=0.13), PTH: 8.3 (IQR: 5.8; 13.8) vs. 12.9 (IQR: 12.0; 16.0) pg/ml (p=0.34), Z-score in lumbar spine: -1.2 (IQR: -2.7; -0.1) vs. -1.8 (IQR: -2.8; -1.1) (p=0.48) and Z-score in total body: -2.1 (IQR -2.6; -1.5) vs. -2.4 (IQR: -3.0; -2.0) (p=0.37). Hypercalciuria had 88.8% (8/9) of children (0.15 (IQR: 0.12; 0.19) mmol/kg/day) at first follow-up and 44.4% (4/9) (0.09 (IQR: 0.08; 0.16) mmol/kg/day) in last examination (p=0.13). ALP blood levels were elevated in all patients (9/9) at first and most recent visit, but ALP Z-score were significant lower at last follow-up: 3.9 (IQR: 1.2; 5.1) vs. 0.57 (IQR: -0.36; 2.1) (p=0.04). There were significant correlations between doses of oral phosphate supplements and ALP Z-score (r=-0.68; p=0.04) and total body Z-score (r=0.78; p=0.03). There was no significant correlations between ALP Z-score and total body Z-score (r=-0.3) or lumbar spine Z-score (r=-0.1). Conclusion The present study demonstrated that treatment of HHRH with low doses (&amp;lt;20 mg/kg/day) of oral phosphorus supplements led to decreasing of ALP Z-score in 7/9 (77.8%) and hypercalciuria in 5/9 (55.6%) of patients. However, that therapy didn’t improve significantly height and severity of rickets, as well didn’t led to normalization of serum phosphorus in children with HHRH. It is therefore conceivable that higher daily doses of phosphate supplements are needed to normalize all clinical and radiological features of disease. Lack of association between ALP Z-score and bone mineral density severity on radiographs limits the value of serum ALP as the indicator of rickets activity.

Age-dependent changes in bone mineral density for males and females aged 10-80 years

BACKGROUND: One of the most accurate and highly reproducible techniques is dual- energy x-ray absorptiometry (DXA). DXA device used to measure BMD, BMC, T-score, Z-score, and consequently used to measure fat mass (FM) and lean mass (LM) for different body sites such as arms, ribs, thoracic spine, lumbar spine, pelvis, legs and whole body. DXA technique is widely used in clinical application researches like diagnosing and treating osteoporosis in elderly men and women with different diseases and assessment of skeleton status. METHODS: One hundred and seventy-six males and females participated in the current study consisting of 48 males and 128 females were evaluated by Dual Energy X-ray Absorptiometry (DXA). RESULTS: The estimated correlation coefficients values were as follows: total BMD depending on segmental BMD of arms, legs were fitted with correlation coefficient of (r=0.92) and (r=0.91) respectively; also it were fitted with (r=0.85), (r=0.84), (r=0.73), (r=0.70), and (r=0.65) for head, pelvis, ribs, thoracic spine and lumber spine respectively; p<0.0001. CONCLUSION: The mean total bone mineral density BMD of the total body for both genders shows highly significant; (p-value = 0.0001) through the ages (20-29). The same results are shown in the ages of (60-69) years with a significant relationship between males and females; (p=0.01). All the other groups (10-19), (30-39), (40-49), (50-59) and (70-80) years showed no significant relationship between both genders, where all mean total BMD amounts were small in female subgroups; p>0.01.

Muscle mass measurements in hip fracture patients and control general population depending on dual-energy X-ray absorptiometry device used: The General Electric Lunar and Hologic systems

ObjectivesThe prevalence of sarcopenia, an independent risk factor for fragility fractures, is high in geriatric hip fracture patients. We aim to compare patients with hip fractures to the general population using different dual-energy X-ray absorptiometry (DXA) devices – General Electric (GE) Lunar and Hologic. MethodsWe retrospectively reviewed data of patients diagnosed with osteoporotic hip fractures. At our institute, 252 patients with hip fractures were measured with the GE Lunar DXA. The control group included 252 matched individuals from a general population dataset whose data were measured with the Hologic DXA; controls were selected using nearest-neighbor propensity score matching. Measurements included appendicular lean mass (ALM), bone mineral density, and subsequent rates of sarcopenia and osteoporosis. ResultsThe BMD T-score was significantly lower in patients with hip fractures than in matched controls (−2.7 vs. −2.1, respectively; P < 0.001). However, mean lean body mass of the arm was significantly greater in the hip fractures group compared to the matched control groups (4.092 kg vs. 3.869 kg, respectively; P = 0.024). Additionally, mean lean body mass of the leg was similar between groups (11.565 kg vs. 11.986 kg, respectively; P = 0.084). ALM/height2 and subsequent sarcopenia rates were not different between groups (hip fractures and 6.257 kg/m2 and 38.5%; matched controls, 6.198 kg/m2 and 33.7%). ConclusionsDespite experiencing hip fractures, muscle mass measurements and sarcopenia prevalence were similar between the groups. Muscle mass measurements for evaluating sarcopenia present significant discrepancies according to the DXA used.

Effects of metabolic syndrome on bone health in older adults: the Bushehr Elderly Health (BEH) program.

The results of previous reports in regard to the effect of metabolic syndrome (MetS) on bone health are not conclusive. This study aimed to evaluate the association between MetS with bone mineral density (BMD) and trabecular bone score (TBS) as an indicator of bone quantity and quality, respectively. Using a cross-sectional design, this study was carried out based on the data collected during the BEH Program, stage II. MetS was defined according to NCEP-ATP III criteria. BMD (at the lumbar spine and the hip) and lumbar spine TBS were assessed by dual-energy X-ray absorptiometry device. The data of 2380 participants (women= 1228, men= 1152) aged ≥ 60 were analyzed. In the fully adjusted regression models (including BMI), significant associations between MetS and mean BMD were observed across all locations in men (P values ≤ 0.001) and in the lumbar spine in women (P value = 0.003). In addition, the prevalence of osteoporosis (based on BMD) was significantly lower in those with MetS than those without MetS in both sexes, even after full adjustments (women, OR = 0.707, P value = 0.013; men, OR = 0.563, P value = 0.001). In contrast, in age-adjusted regression analyses, the prevalence of degraded bone microarchitecture (TBS ≤ 1.2) was significantly increased in those with MetS than those without, irrespective of the participants' sex (P values < 0.05). The mean TBS was also negatively associated with MetS in women (β= - 0.075, P value = 0.007) but not in men (β= - 0.052, P value = 0.077), in age-adjusted regression models. However, after including BMI in the adjusted models, all significant associations between TBS values and MetS disappeared. It seems that a positive association exists between MetS and BMD, while MetS is either not associated or negatively correlated with bone quality as measured by TBS.

Development of Osteoporosis Screening Algorithm for Population Aged 50 Years and above in Klang Valley, Malaysia.

Background: The current osteoporosis screening instruments are not optimized to be used among the Malaysian population. This study aimed to develop an osteoporosis screening algorithm based on risk factors for Malaysians. Methods: Malaysians aged ≥50 years (n = 607) from Klang Valley, Malaysia were interviewed and their bone health status was assessed using a dual-energy X-ray absorptiometry device. The algorithm was constructed based on osteoporosis risk factors using multivariate logistic regression and its performance was assessed using receiver operating characteristics analysis. Results: Increased age, reduced body weight and being less physically active significantly predicted osteoporosis in men, while in women, increased age, lower body weight and low-income status significantly predicted osteoporosis. These factors were included in the final algorithm and the optimal cut-offs to identify subjects with osteoporosis was 0.00120 for men [sensitivity 73.3% (95% confidence interval (CI) = 54.1%–87.7%), specificity 67.8% (95% CI = 62.7%–85.5%), area under curve (AUC) 0.705 (95% CI = 0.608–0.803), p < 0.001] and 0.161 for women [sensitivity 75.4% (95% CI = 61.9%–73.3%), specificity 74.5% (95% CI = 68.5%–79.8%), AUC 0.749 (95% CI = 0.679–0.820), p < 0.001]. Conclusion: The new algorithm performed satisfactorily in identifying the risk of osteoporosis among the Malaysian population ≥50 years. Further validation studies are required before applying this algorithm for screening of osteoporosis in public.