Dual-energy X-ray Absorptiometry Values Research Articles

Transcutaneous electrical stimulation therapy and genetic analysis in Dercum's disease: A pilot study.

Dercum's disease (DD), or adiposis dolorosa, is a rare condition of unknown etiology characterized by growth of painful subcutaneous adipose tissue. No specific treatment exists. Pain is often invalidating and resistant to analgesic drugs. We tested the efficacy of Frequency Rhythmic Electrical Modulation System (FREMS) therapy on pain relief. Subcutaneous biopsies were performed for genetic analysis.Nine DD patients were enrolled. Five cycles of FREMS at 3-month intervals during 1 year were administered. Visual analogue scale (VAS), Bartel Index Questionnaire and Short Form 36 questionnaire were used to measure pain and general health status at baseline, 6 and 12 months. Dual-energy X-ray absorptiometry (DEXA) quantified fat mass. Next-Generation Sequencing (NGS) was performed on adipose tissue biopsies and peripheral blood sample to search for somatic variants and specific protein pathway mutation.Seven patients were included in the final analysis. FREMS induced a reduction in VAS score (from 92 to 52.5, P = .0597) and a significant improvement in SF-36 domains (Physical functioning, Role limitation due to physical health, Body pain, Vitality, Social functioning, P < .05). No modification in anthropometrics and DEXA values was observed. The analysis of the mitochondrial Displacement loop (D-loop) region confirmed the clonality of all lipomatous lesions. The presence of the mitochondrially encoded tRNA-Lysine (MT-TK) m.8344A>G variant, occasionally identified in patients with multiple symmetric lipomatosis, was excluded in all subjects. On the other hand, we observed variants in genes belonging to signaling pathways involved in cell cycle and proliferation (Phosphoinositide 3-kinase/AKT/mTOR, MAPK/ERK, and Hippo).FREMS can be a useful tool to alleviate pain and improve overall quality of life in patients with DD. Genetic analysis highlighted the molecular heterogeneity of lipomas.

Bone mineral concentration predicted by dual energy X-ray absorptiometry and its relationship with lamb eating quality

Lumbar bone mineral concentration, as predicted by dual energy x-ray absorptiometry (DEXA), may reflect changes in lamb maturity and eating quality. New season (n = 60) and old season (n = 60) lambs were slaughtered and DEXA scanned at a commercial abattoir across 2 kill groups. The second lumbar vertebra was isolated from the spine for determination of calcium, phosphorus, and magnesium concentration (mg/g). The loin and rack cuts were collected for consumer sensory grilling and roasting analyses. Mineral concentration was significantly higher in old season lambs within kill group 1 (P < 0.05). DEXA was a positive predictor of phosphorus and calcium concentration, but only when DEXA lean % (P < 0.05) was included in the model. Calcium and phosphorus were significant positive predictors of overall liking scores (P < 0.05), but only for the rack roast. These effects became insignificant when DEXA lean % was included. These results suggest that DEXA values likely reflect changes in both DEXA lean % and bone minerals, and that DEXA lean % was the driver of eating quality, rather than maturity.

Muscle Assessment by Ultrasonography: Agreement with Dual-Energy X-Ray Absorptiometry (DXA) and Relationship with Physical Performance.

Different methods have been proposed to study skeletal muscle mass in sarcopenia diagnosis, although all have inherent drawbacks. The aim of this study was to evaluate the utility of muscle ultrasound in muscle assessment by studying its correlation with dual-energy x-ray absorptiometry (DXA) and calf circumference (CC), cut-off values for ultrasound-based detection of low muscle mass, and the correlation with muscle performance. Fifty-seven participants older than 70 years, underwent a muscle ultrasound study, DXA, calf circumference (CC) and functional assessment. Ultrasound measurements were taken in the femoral quadriceps (transverse plane) and in the medial gastrocnemius (transverse and longitudinal planes). Muscle function was assessed by gait speed, Short Physical Performance Battery (SPPB) and grip strength. Median age was 78.9 years (IQR 74.9 - 81.9), and 33 were women (57.9%). We found good correlation between muscle thickness of gastrocnemius muscle in transverse and longitudinal plane and appendicular lean mass measured by DXA (r=0.546 and r=0.689 respectively) and good correlations between muscle thickness of gastrocnemius in transverse and longitudinal plane with CC (r=0.651 and r=0.447 respectively). The thickness of gastrocnemius medialis optimal cut-off points for low muscle mass were 18,5mm in the transverse plane (Sensitivity: 77,8%, Specificity: 77,1%), and 17.3mm in the longitudinal plane (Sensitivity: 100%,Specificity: 68.8%). Muscle thickness was also significantly correlated with gait speed, SPPB and grip strength. Measures of gastrocnemius medialis thickness obtained by ultrasound are reliable and correlate well with DXA and CC values and muscle performance.

POS1111 DIAGNOSIS OF OSTEOPOROSIS USING RADIOFREQUENCY ECHOGRAPHIC MULTI SPECTROMETRY (REMS) AT THE LUMBAR SPINE IN PATIENTS WITH DIFFERENT BODY MASS INDEX

Background:In recent years, the technology based on the analysis of raw ultrasound signals, Radiofrequency Echographic Multi Spectrometry (REMS), has been validated against Dual-energy X-ray Absorptiometry (DXA) for the diagnosis of osteoporosis and risk fracture prediction.Objectives:The aim of this multicenter observational study was to evaluate the diagnostic performance of REMS with respect to DXA in patients with different body mass index (BMI) categories.Methods:The inclusion criteria were: Caucasian women; age between 30 and 90 years; referral by their clinician for spinal DXA assessment; absence of significant walking impairment; signed informed consent.Patients underwent DXA and REMS scans at the lumbar spine, according to the procedures described in Di Paola et al. [1], including an a-posteriori quality check of the examinations in order to guarantee the maximum reliability of the diagnostic outputs.Three groups of patients were considered according to BMI:: underweight (BMI&lt;18.5 kg/m2), normal weight (BMI≥18.5 kg/m2 and &lt;25 kg/m2), and overweight/obese (BMI≥25 kg/m2). DXA and REMS BMD values were also stratified in 3 diagnostic categories: osteoporotic, osteopenic, or healthy.The degree of correlation between DXA and REMS BMD values was quantified by calculating Pearson’s correlation coefficient (r). The diagnostic concordance between REMS and DXA was assessed by Cohen’s K considering the 3 diagnostic categories. REMS´s sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for discriminating patients with and without osteoporosis were also calculated using DXA outcomes as reference. The same statistics were calculated accepting a 0.3 T-score tolerance on T-score values of borderline cases [1].Results:Overall, 4282 patients were enrolled and, after the quality check, 3501 couples of scans were included in the analyses. Of these patients, 122 (3.5%) were underweight, 1964 (56.1%) were normal weight, and 1415 (40.4%) were overweight. The results of the diagnostic performance in patients after BMI stratification are reported in Table 1.Conclusion:We observed an excellent correlation between REMS-based diagnosis with respect to the osteoporosis diagnosis performed by DXA in patients from each BMI category. These results indicate that lumbar spine REMS analysis is a suitable and accurate diagnostic tool for patients with different BMI.

Bone mineral density assessment by DXA in rheumatic patients with end-stage osteoarthritis undergoing total joint arthroplasty

BackgroundPatients with rheumatic diseases have a high risk for joint destruction and secondary osteoarthritis (OA) as well as low bone mineral density (BMD, i.e., osteoporosis). While several factors may lead to low BMD in these patients, the value of BMD measurements in rheumatic patients with end-stage OA scheduled for total joint arthroplasty is unknown.MethodsIn this retrospective cross-sectional study of 50 adults with secondary OA due to rheumatic diseases, we evaluated dual energy X-ray absorptiometry (DXA) measurements of both hips and the spine performed within 3 months prior to arthroplasty (n = 25 total hip arthroplasty, THA; n = 25 total knee arthroplasty, TKA). We analyzed various demographic and disease-specific characteristics and their effect on DXA results by using group comparisons and multivariate linear regression models.ResultsAlthough patients undergoing TKA were younger (63.2 ± 14.2 vs. 71.0 ± 10.8 yr., p = 0.035), osteoporosis was observed more frequently in patients scheduled for TKA than THA (32% vs. 12%). Osteopenia was detected in 13/25 patients (52%) in both the THA and TKA cohort. In the THA cohort, female sex, lower BMI and prednisolone use were associated with lower T-score in the hip. In TKA patients, higher OA grade determined by Kellgren-Lawrence score was associated with lower T-score in the hip of the affected side.ConclusionsOsteoporosis is present in a considerable frequency of rheumatic patients with end-stage OA, and THA and TKA patients show distinct frequencies and risk factors of low BMD. Our findings point to a potential value of DXA regarding preoperative evaluation of bone status.

Effect of tamoxifen with or without gonadotropin-releasing hormone analog on DXA values in women with breast cancer

The purpose of this study was to compare the changes in DXA values including trabecular bone score (TBS) and bone mineral density (BMD) of lumbar spine (LS) and femur according to the hormone therapies including tamoxifen (TMXF) treatment with or without gonadotropin releasing hormone analog (GnRH analog) in women with breast cancer. We enrolled 119 women with breast cancer who had undergone breast-conserving surgery or mastectomy followed by TMXF treatment for postmenopausal women (TMXF group, n = 63, 52.9%) or by combination therapy of TMXF combined with GnRH analog for premenopausal women (TMXF + GnRH group, n = 56, 47.1%) from December 2013 to December 2017. The median follow-up period was 13 months (interquartile range [IQR], 12.0–14.75) for TMXF group and 13.5 months (IQR, 12.00–16.00) for TMXF + GnRH group, respectively. Patients did not receive bone-modifying therapy. The baseline dual-energy X-ray absorptiometry (DXA) scan before breast cancer surgery and follow-up DXA during hormone therapy. Comparing the first and follow-up DXA results, BMD in LS were significantly decreased in both TMXF (P < 0.001, mean difference: − 0.06) and TMXF + GnRH (P < 0.001, mean difference: − 0.09) groups. BMD values of femoral neck (P = 0.0011, mean difference: − 0.01) and total femur (P < 0.001, mean difference: − 0.03) was significantly changed between the baseline and follow-up DXA in TMXF + RnRH group. In the TMX group, a significant changed occurred in the BMD in total femur (P < 0.001, mean difference: − 0.030) but not the BMD of femoral neck (P = 0.095, mean difference: − 0.007). Regarding TBS, no significant change was found in the TMXF (P = 0.574, mean difference: − 0.004) group, whereas there was a significant decrease in TBS in the TMXF + GnRH (P < 0.001, mean difference: − 0.02) group during follow-up. TBS is more sensitive in reflecting the bone microarchitecture changes by TMXF or GnRH agonist in breast cancer patients than BMD. This finding demonstrates that TBS can be a useful parameter to detect bone microarchitectural changes in clinical applications.

Accuracy of Computed Tomography Attenuation Value of Lumbar Vertebra to Assess Bone Mineral Density.

BackgroundComputed tomography (CT) attenuation (Hounsfield unit [HU]) value of lumbar vertebra may provide an alternative method in the detection of osteoporosis during CT scans.MethodsA cross-sectional study on 50 patients of age 50 and above with contrast-enhanced CT (CECT) and dual-energy X-ray absorptiometry (DXA) was conducted from November 2018 to November 2019. Single region of interest (ROI) was placed at the anterior trabecular part of L1 vertebra on CECT to obtain HU value. Correlation of CT HU value of L1 vertebra and DXA T-score, interrater reliability agreement between HU value of L1 vertebra and T-score in determining groups of with and without osteoporosis, ROC curve analysis for diagnostic accuracy and cut-off value of CT for detection of osteoporosis were identified.ResultsSignificant correlation between HU value of L1 vertebra and L1 T-score (r = 0.683)/lowest skeletal T-score (r = 0.703) (P < 0.001). Substantial agreement between HU value of L1 vertebra and DXA in determining the groups with and without osteoporosis (k = 0.8; P < 0.001). The area under the receiver operating characteristic (AUROC) curve was 0.93 (95% CI: 0.86, 1.00) using HU value (P < 0.001). Cut-off value for osteoporosis was 149 HU.ConclusionHU value of lumbar vertebra is an effective alternative for the detection of osteoporosis with high diagnostic accuracy in hospitals without DXA facility.

Radiofrequency Echographic Multi Spectrometry (REMS) for the diagnosis of osteoporosis in a European multicenter clinical context.

Radiofrequency Echographic Multi Spectrometry (REMS) is a non-ionizing technology for the densitometric assessment of osteoporosis. It has already been validated in Italian women with respect to the current clinical reference technology, Dual-energy X-ray Absorptiometry (DXA). Aim of the current study was to assess the diagnostic accuracy of REMS technology with respect to DXA in a wider European clinical context. A total of 4307 female Caucasian patients aged between 30 and 90years underwent DXA and REMS scans at femoral neck and/or lumbar spine (the site depending on the medical prescription). The acquired data underwent a rigorous quality check in order to exclude the erroneous DXA and REMS reports. The diagnostic agreement between the two technologies was assessed, also stratifying for patients' age groups. The ability to recognise previously fractured patients was also investigated. Overall, 4245 lumbar spine scans and 4271 femoral neck scans were performed. The ability to discriminate patients with and without osteoporosis by femoral neck investigation resulted in sensitivity and specificity of 90.4% and 95.5%, respectively. For lumbar spine scans, a sensitivity of 90.9% and a specificity of 95.1% were obtained. The areas under the curve (AUCs) of the Receiver Operating Characteristic (ROC) curve evaluating the ability to discriminate groups of patients with previous osteoporotic fracture using DXA and REMS T-score values were 0.631 and 0.683 (p<0.0001), respectively, for femoral neck scans, whereas 0.603 and 0.640 (p=0.0002), respectively, for lumbar spine scans. The diagnostic effectiveness of REMS technology at reference anatomical sites for the assessment of osteoporosis has been confirmed in a large series of female patients, spanning from younger and pre-menopausal to elderly women up to 90years, in a multicenter European clinical context.

207. Postmenopausal women presenting for spinal fusion surgery have abnormal microarchitecture despite normal DXA

BACKGROUND CONTEXT More than 400,000 spinal fusion surgeries are performed annually in the US, with related health care costs exceeding $287 billion. As spinal fusion involves extensive instrumentation of the vertebrae, patients with skeletal abnormalities may be at increased risk for complications. However, preoperative identification of high-risk patients remains a challenge. Due to skeletal effects of aging and estrogen deficiency, postmenopausal (PM) women may be at particular risk. Dual energy x-ray absorptiometry (DXA) measurements of areal BMD are subject to artifact in patients with spinal pathology, and may be limited as screening tests. PURPOSE This prospective study investigated skeletal health in postmenopausal women having lumbar spine fusion and matched controls using DXA and high resolution peripheral QCT (HRpQCT) measurements of volumetric BMD (vBMD) and microarchitecture. We aimed to determine if HRpQCT would reveal additional abnormalities in vBMD and microarchitecture in fusion patients compared to DXA. STUDY DESIGN/SETTING Prospective, single center study. PATIENT SAMPLE A total of 60 patients were included in this study. PM women undergoing lumbar fusion were prospectively enrolled and compared to PM controls. OUTCOME MEASURES HRpQCT measurements of cortical and trabecular vBMD and microarchitecture, DXA, age and BMI. METHODS PM women undergoing lumbar fusion (n=20) were matched 1:2 by age with PM controls (n=40) who had no history of spine surgery or secondary osteoporosis. Subjects had assessments by standard DXA and high resolution peripheral QCT (HRpQCT) to measure cortical (Ct) and trabecular (Tb) vBMD and microarchitecture of the distal radius and tibia. RESULTS Mean age of subjects was 66+/-6 years, BMI (28+/-6 kg/m2) without any significant differences between groups. By DXA, T-scores in fusion patients were normal at the lumbar spine (mean 0.0) and osteopenic at the total hip (-1.2), femoral neck (-1.5) and 1/3 radius (-1.5). T- Scores did not differ significantly from controls at any site. In contrast, HRpQCT revealed low vBMD (total, Ct, Tb) in fusion patients compared to controls at both radius and tibia, with total vBMD 21-30% lower, Ct density ∼7% and Tb density ∼25% lower. Fusion patients had microarchitectural abnormalities, significantly fewer, thinner and more widely spaced trabeculae. Specifically, Tb number was 9% lower, Tb thickness 6% lower, and Tb separation 23% greater at the radius with similar differences at the tibia. CONCLUSIONS In summary, PM women presenting for spine fusion surgery had low volumetric BMD and abnormal trabecular microarchitecture, despite DXA values that were normal or slightly low. Our results suggest that additional techniques may be necessary for detection of bone quality deficits in patients presenting for spinal fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Body composition with dual energy X-ray absorptiometry: from basics to new tools.

Dual-energy X-ray absorptiometry (DXA) in nowadays considered one of the most versatile imaging techniques for the evaluation of metabolic bone disorders such as osteoporosis, sarcopenia and obesity. The advantages of DXA over other imaging techniques are the very low radiation dose, its accuracy and simplicity of use. In addition, fat mass (FM) and lean mass (LM) values by DXA shows very good accuracy compared to that of computed tomography and magnetic resonance imaging. In this review we will explain the technical working principles of body composition with DXA, together with the possible limitations and pitfalls that should be avoided in daily routine to produce high-quality DXA examinations. We will also cover the current clinical practical application of whole body DXA values, with particular emphasis on the use of LM indices in the diagnostic workup of reduced muscle mass, sarcopenia and osteosarcopenic obesity according to the most recent guidelines. The possible use of adipose indices will be considered, such as the fat mass index (FMI) or the android/gynoid ratio, as well as lipodystrophy indices and the evaluation of visceral adipose tissue (VAT). Whenever available, we will provide possible cut-off diagnostic values for each of these LM and FM indices, according to current literature and guidelines.

SAT-405 Trabecular Bone Score (TBS) in Primary Hyperparathyroidism (PHP): A Useful Tool?

Background: PHP is a common disorder, and regardless of being an asymptomatic entity, often leads to bone loss and osteoporosis. TBS is a software-based assessment method of trabecular bone structure of the spine based on the analysis of pixels in dual energy x-ray absorptiometry (DXA) images. The aim of this study was to evaluate TBS measurements in combination with DXA values by searching for more accurate bone fragility risk assessment among PHP patients. Methods: From June/2017 to January/2019, all patients who met the criteria for PHP diagnosis prior to surgery were selected to take part in this study. Control group was composed by non-family related healthy volunteers. Bone mineral density (BMD) by DXA (DXA; Hologic QDR 4500) at the lumbar spine, total hip, femoral neck, distal third of the non-dominant radius and TBS values by InSight were determined in 64 PHP patients and 63 controls. Total and ionized calcium, PTH, 25-hydroxyvitamin D (25(OH)D), creatinine, alkaline phosphatase, P1NP and CTX were measured in all patients and control group. Results: Primary hyperparathyroidism patients presented significant lower BMD values in all evaluated sites compared to controls. TBS measurements were also statistically different among PHP patients and controls (mean TBS PHP=1233 vs TBS controls= 1280, p=0.044). Patients and controls didn’t differ in age, sex, menopausal state or BMI (body mass index). Osteoporosis diagnosis by DXA analysis was observed in 50% of PHP patients and in 26.6% of controls. Self-reported or image-diagnosed fracture occurred in 15 PHP (23.4%) patients and in 11 (17.5%) controls. Among these fractures, vertebral fracture account for 9 (14%) in PHP group and 4 (6.3%) in controls. ROC curve analysis showed that the TBS value < 1187 is associated to significant high risk of vertebral fracture (sensibility 87.5%, specificity 67.3%) among PHP patients. Conclusion: TBS, used as a complement to DXA measurements, is a useful tool to better assess fragility risk among PHP patients.

Comparison of Body Mass Index, Skinfold Thickness, and Bioelectrical Impedance Analysis With Dual-Energy X-Ray Absorptiometry in Hemodialysis Patients.

Malnutrition is a consistent finding in hemodialysis (HD) patients and is associated with high mortality. The aim was to compare nutrition status indicators using dual-energy x-ray absorptiometry (DXA) as reference in HD patients. Observational cross-sectional study with 42 patients, 55.8 years (±14.6) old, 60% male, HD 2-3 times per week for ≥3 months. HD ranged from 3 months to 28 years (median, 17.3; interquartile range, 8.73-39.0). We used body mass index (BMI) and fat mass (FM) by skinfold thickness (SFT), bioelectrical impedance analysis (BIA), and DXA. Statistical analyses used Bland-Altman plots, Lin's concordance correlation coefficient, the paired t-test, and Pearson or Spearman correlation. P < .05 was significant. SFT and DXA presented the lowest prevalence of malnutrition (2.4%) and BMI the highest (28.6%). BMI, BIA FM, and SFT FM presented strong positive correlations with DXA FM (r = 0.915; r = 0.976; r = 0.910, P < .001, respectively). BIA FM and fat-free mass (FFM) demonstrated substantial agreement with DXA values (ρ = 0.974 and 0.960, P < .001). Thus, the measurement procedures used, SFT and BIA, underestimated %FM (-4.65% and -2.13%) and overestimated FFM (3.12 kg and 1.0 kg) according to DXA. No differences were found between mean values of BIA FM and DXA (P = .178). Compared with DXA, BIA was the most appropriate nutrition indicator for measuring body composition.

Abstract P344: Comparison of Visceral Adipose Tissue Measurements in Adolescents Between Magnetic Resonance Imaging and DXA

Introduction: Excess Visceral Adipose Tissue (VAT) is linked to cardiometabolic risk in adolescents. VAT is mainly measured using Magnetic Resonance Imaging (MRI), yet dual-energy x-ray absorptiometry (DXA) is more affordable and available. The purpose was to compare VAT from MRI and DXA in adolescents. Methods: Adolescents 10-16 years of age were recruited. Abdominal MRI was performed using a General Electric (GE) Signal Excite scanner (3.0 Tesla; GE Medical Systems) with IDEAL-IQ imaging software. A series of scans between specific points on the liver and kidney were conducted. A trained technician manually drew VAT and used additional calculations to determine VAT volume (L). A whole-body DXA (GE iDXA scanner) was performed and software calculated VAT within the android region. Paired samples t-tests were used to determine differences between VAT values, within sex, race (White, African American, and Other race), and BMI categories (normal, overweight, and obese). VAT values were standardized to a mean of zero and unit standard deviation and compared with a Bland Altman plot. Results: A total of 330 adolescents participated. The mean age was 12.6±1.9 years, and the sample was 52.3% female, 58.5% White, 14.7% overweight (14.7%), and 33.5% obese. Average VAT from MRI (0.58±0.47 L) and DXA (0.35±0.41 L) significantly differed ( p =0.001). The error and absolute error were -0.23 ±0.20 L and 0.23±0.20 L respectively, with DXA measuring lower than MRI. DXA values were significantly lower from MRI values for each sex, race, and BMI categories ( p &lt;0.01 for all). DXA values were closest to MRI values in African American adolescents (-0.14 ±0.20 L) and furthest away for those who had overweight (-0.31±0.17 L). All standardized values fell within ±1.96 standard deviations (Figure 1). Conclusions: In this sample, DXA measured VAT values were consistently lower overall and in subgroups compared to MRI. In general, DXA values were not comparable to MRI values.

Validity of Field Methods to Estimate Fat-Free Mass Changes Throughout the Season in Elite Youth Soccer Players.

The aim of this study was to determine the most effective anthropometric equations or bioelectrical impedance analysis (BIA) devices for quantifying the sensitivity to change in fat-free mass (FFM) in elite young soccer players, in comparison with measurements using dual-energy X-ray absorptiometry (DXA), between the pre- and mid-season. A total of 40 elite youth soccer players participated in this study. DXA values provided a criterion measure of FFM. Correlation coefficients, biases, limits of agreement, and differences were used as measures of sensitivity to change. All body density, skinfold, and anthropometric equations and BIA devices used to obtain FFM data showed positive and very large correlations (r from 0.70 to 0.89) with DXA. A significant increase in FFM was shown between time points using DXA, BIA, and all anthropometric equations (p < 0.01). The magnitudes of differences were small for DXA, BIA inbody and all anthropometric equations except those of Faulkner (1966), Durnin and Rahaman (1967), Brook (1971), and Sarría et al. (1998). Six anthropometric equations [Faulkner (1966), Durnin and Womersley (1974), Carter (1982), Slaughter et al. (1988), Reilly et al. (2009), and Munguia-Izquierdo et al. (2018)] and BIA Tanita showed no statistical differences compared to DXA, with a low bias. We concluded that the equations developed by Durnin and Womersley (1974), Carter (1982), Slaughter et al. (1988), Reilly et al. (2009), and Munguia-Izquierdo et al. (2018) showed the best sensitivity in assessing FFM changes between pre- and mid-season in elite youth soccer players.

Field Methods to Estimate Fat-free Mass in International Soccer Players.

Based on the high financial and logistical costs associated with the assessment of body composition with dual-energy X-ray absorptiometry (DXA), this study determined which field method has the best correlation with DXA data, and developed an equation to estimate fat-free mass (FFM) using the field anthropometric data in international soccer players. A total of 17 international soccer players participated in this study. DXA values provided a criterion measure of FFM. Correlation coefficients, biases, limits of agreement, and differences were used as validity measures, and regression analyses were used to develop the prediction equation. All field methods used to obtain FFM data showed positive correlations (r from 0.90-0.96) with DXA. Only the equation developed by Deurenberg et al. [6] showed no differences from DXA with a low bias. The main strength of this study was providing a valid and accurate equation to estimate FFM specifically in international soccer players.

Quantitative ultrasound for monitoring bone status in institutionalized adults with refractory epilepsy and intellectual disability: A 7-year follow-up study

PurposeLong-term exposure to anti-epileptic drugs has been shown to decrease bone mineral density (BMD). The aim of this 7-year follow-up study was to explore changes in bone status, using quantitative ultrasound (QUS) and Dual-energy X-ray Absorptiometry (DXA) in adults with refractory epilepsy and intellectual disability (ID) residing at a long-term care facility. Both measurements can be challenging to conduct in this population. MethodsIn 2009 and 2016, a total of 126 patients (18–79 years) underwent QUS of the heel and DXA of lumbar spine (LS) and hip (femoral neck (FN) and total hip (TH)). Subgroup analysis was performed for patients with (group A, n = 53) and without (group B, n = 73) bisphosphonate use during follow-up. ResultsOverall, weak to moderate correlations between changes in DXA and QUS parameters were found. For group A, correlations varied from r = .31 to .59, whereas correlations did not exceed r = .40 in group B. Patients in group A showed a larger increase or a smaller decrease in BMD for all DXA regions during follow-up (p < .001 for ΔLS and ΔFN BMD, p = .001 for ΔTH BMD). For change in QUS parameters, no significant difference between groups was found. ConclusionIn this study we demonstrated the limited use of QUS in the monitoring of bone status in our study population. Although correlations between changes in QUS parameters and axial DXA are positive and mostly significant, QUS only explains little of the variability in DXA values and is inadequate for measuring treatment response in this population.

Recovery of Bone Mineral Mass After Upper Limb Fractures in Children and Teenagers.

Loss of bone mineral mass and muscle atrophy are predictable consequences of cast-mediated immobilization following wrist and forearm fractures. This study aimed to prospectively determine whether previously reported lower bone mineral mass following immobilization for wrist and forearm fractures in children and teenagers had recovered at 6- and 18-month follow-up. We recruited 50 children and teenagers who underwent a cast-mediated immobilization for a forearm or wrist fracture. Dual-energy x-ray absorptiometry scans of different skeletal sites were performed at the time of fracture, at cast removal, at 6 and at 18-month follow-up. Injured patients were paired with healthy controls according to sex and age. Dual-energy x-ray absorptiometry values were compared between groups and the injured and uninjured forearms of the patients. At the time of fracture, injured and healthy subjects showed no differences between their bone mineral density (BMD) and bone mineral content (BMC) z-scores at the lumbar spine, or between their BMDs at the peripheral wrist. At cast removal, upper limb bone mineral variables were significantly lower in the injured group (except for the ultradistal radius) than in the uninjured group, with differences ranging from 3.8% to 10.2%. No residual decrease in bone mineral variables was observed at any upper limb site at 6- and 18-month follow-up (28 injured patients). Significant residual increases in the BMDs and BMCs were observed for the injured group's ultradistal radius and whole wrists (+4.8% to +5.2%). A rapid bone mass reversal occurs by resumption of mobilization, with full bone recovery 6 months after a forearm or wrist fracture. Finally, healing bone callus could introduce a bias into the interpretation of BMD and BMC data at the fracture site, not only at cast removal but also 18 months after the fracture.

Dual-Energy X-ray Absorptiometry and Bioelectrical Impedance Analysis are Beneficial Tools for Measuring the Trunk Muscle Mass of Patients with Low Back Pain.

Introduction Limb muscle mass measurement using dual-energy X-ray absorptiometry (DXA) is considered the gold standard for the diagnosis of sarcopenia. Moreover, bioelectrical impedance analysis (BIA) is also recognized as a beneficial tool considering its high correlation with DXA. However, it remains to be elucidated whether DXA and BIA can accurately measure trunk lean mass. The aim of this study was to investigate the correlation between DXA and BIA measurements of trunk muscle mass and the cross-sectional area (CSA) of trunk muscles measured using magnetic resonance imaging (MRI) and to compare measures of trunk muscle mass obtained using DXA and BIA in patients with low back pain (LBP). Methods In total, 65 patients participated in the study. The correlation between DXA and BIA measurements and the CSA of trunk and paraspinal muscles at the L4-5 level were calculated. In addition, the correlation between DXA and BIA measurements of trunk muscle mass and the differences between these two measurements were determined. Results The correlation coefficient between DXA and BIA trunk muscle mass measurement and trunk muscle CSA was 0.74 and 0.56 for men and 0.69 and 0.44 for women, respectively. DXA and BIA measurement values showed a significantly moderate correlation with the CSA of the erector spinae (ES) and psoas major (PM). The multifidus (MF) CSA did not correlate with measurements of DXA and BIA in both men and women. Although DXA and BIA measurements were significantly correlated, a significant difference between these two measurements was found. BIA overestimated the trunk muscle mass significantly compared with DXA. Conclusions Trunk muscle mass measured with DXA and BIA was correlated with the CSA of most trunk muscles. Although the measurement of DXA and BIA showed a high correlation, BIA overestimated trunk muscle mass compared with DXA. Both DXA and BIA are beneficial for measuring trunk muscle mass.

An Ultrasound Prediction Equation to Estimate DXA-Derived Body Fatness for Middle-Aged and Older Caucasian Adults.

Currently, only one study has used dual-energy X-ray absorptiometry (DXA)-derived percent body fat (BF%) as the criterion measure to develop ultrasound prediction equations to estimate BF% in adults between the ages of 50 and 80 years. The aim of this study was to examine the relationship between BF% estimated from subcutaneous fat thickness using a previously published Japanese-based prediction equation and DXA-derived BF% in Caucasian middle-aged and older adults. A secondary aim was to develop a new prediction equation for Caucasian adults if the previously published equation did not predict BF% well in Caucasians. Cross-sectional study. One-hundred and two Caucasian adults aged 50-76 years (59 men and 43 women) had ultrasound fat thickness and DXA values measured. A new BF% prediction model was developed using ordinary least squares multiple linear regression. There was a strong correlation between ultrasound predicted and DXA-derived BF% (r = 0.882, p<0.001). Bland-Altman analysis did not indicate a bias in the prediction of BF% for Caucasian adults (r = -0.092, p>0.05). However, the predicted BF% was significantly higher compared to DXA-derived BF% (approximately 4%). A newly developed nonlinear prediction model used to estimate BF% was significant [F(17,84) = 33.44, p<0.001] with an R2 of 0.871 and an adjusted R2 of 0.845. When examining the stability of the model, bootstrapping (n=1000) resulted in an optimism value of 0.1135 so that the corrected R2 was 0.758. After removing an outlier, the model was significant [F(17,83) = 34.82, p<0.001] and it's R2 was 0.877 and adjusted R2 was 0.852. The developed equation was stable with a high degree of variance compared to results from previous studies. The results of this study also suggest that ethnicity should be considered when choosing which prediction equations should be used to estimate BF%.

Screening Post-menopausal Women for Bone Mineral Level by Bioelectrical Impedance Spectroscopy of Dominant Arm.

Dominant arm bioimpedance spectroscopy (BIS) and lumbar and hip dual energy X-ray absorptiometry (DXA) measurements were conducted simultaneously on 48 post-menopausal women, aged between 43 and 86 years, with no hip or arm fracture history at Department of Radiology of Istanbul University Cerrahpasa Hospital. According to lumbar DXA results, 21 women were classified as normal, 22 as osteopenia and 5 as osteoporosis; whereas hip DXA results classified 30 women as normal, 15 as osteopenia and 3 as osteoporosis. Only 26 participants had identical lumbar and hip bone mineral density (BMD) diagnostic results. Dominant arm characteristic frequencies of normal subjects were statistically significantly different from osteoporotic subjects based on both lumbar (p < 0.005) and hip classification groups (p < 0.001). Hip and lumbar spine DXA BMD values were significantly correlated (r = 0.55, p < 0.005). The dominant arm BIS characteristic frequency, considered as the single predictor in earlier diagnosis of osteoporosis, was found negatively correlated with DXA measurements for both hip and lumbar spine regions. The Spearman rank correlation coefficient of BIS values with the hip DXA values (r = -0.53, p < 0.001) was higher than that of lumbar spine (r = -0.37, p < 0.001). In receiver operating characteristic (ROC) curve analysis, the best discrimination of dominant arm characteristic frequency was made between normal and osteoporotic subjects based on the hip subgroups (p < 0.001). Both lumbar bone mineral content (BMC) (r = -0.47, p < 0.001) and hip BMC (r = -0.4340, p < 0.005) were statistically significantly correlated with dominant arm characteristic frequency.