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Eighty-three male and female (49/34) athletes underwent determination of total fat mass (FM), lean mass (LM), bone mineral density (BMD) and visceral adipose tissue (VAT) by dual X-ray absorptiometry during the pre-season, in-season and off-season. Athletes were classified by position of Goalie (G; M/F=7/6), Forward (F; M/F=26/18), or Defenseman (D; M/F=16/10). In males, all positions were similar in weight, FM, LM, BMD and VAT. In females, F weighed less than D and G. FM and VAT was lower in F than D and G, but D was not different from G. LM was lower in F compared to D, but not G, with no differences between D and G. There were no differences in BMD between positions. There were no seasonal changes in males for body composition variables. In females, FM, LM and VAT decreased from pre-season to in-season, while BMD increased. From in-season to off-season, LM increased and BMD decreased. From off-season to pre-season, FM and VAT increased. In conclusion, there were no differences across position or seasonal changes in body composition in males. However, there were positional and seasonal changes in body composition in females, indicating possible differences in training regimens during the off-season compared to males.

This cross-sectional study aimed to examine the degree of whole-body morphological asymmetries in female tennis players. Data were collected in 19 high-level female tennis players (21.3 ± 3.4 years). Based on anthropometric measurements (upper arm, lower arm, wrist, upper leg and lower leg circumferences as well as elbow and knee widths) and dual x-ray absorptiometry research scans (bone mineral density (BMD), bone mineral content (BMC), lean mass (LM), fat mass (FM) as well as humerus, radio-ulnar, femur and tibia bone lengths), within-subject morphological asymmetries for both upper (dominant vs. non-dominant) and lower (contralateral vs. ipsilateral) extremities were examined. Upper arm (p = 0.015), lower arm (p

Pompe disease is a rare autosomal recessive disorder caused by the deficiency of acid α-glycosidase resulting in accumulation of glycogen in the lysosomes. The late-onset form of the disease (LOPD) causes primarily progressive muscle weakness and respiratory insufficiency. Enzyme replacement therapy (ERT) introduced in 2006, showed mild improvement or stabilization of the symptoms although long-term data are limited. Aim of the study was to describe the progression of body composition and walking ability in LOPD patients receiving ERT consistently for 9 years.Lean body mass, bone mineral density, body fat and 6 min walking distance were assessed in three male and three female LOPD patients (height 165.8 ± 11.2 cm, age 42.3 ± 11.8yrs, body mass 71.1 ± 20.8 kg, at study entry), every three years, for 9 years since ERT initiation (T0, T3, T6, T9).Total body and upper extremities' lean mass remained unchanged (The current data show that enzyme replacement therapy may preserve lean body mass, bone mineral density and walking capacity in LOPD patients.

Background: Melorheostosis is a rare sporadic sclerosing bone dysplasia, which commonly affects appendicular skeleton with bone hyperostosis and soft tissues sclerosis; fragility fractures are rare in melorheostotic patients. We investigated bone features at unaffected sites in a postmenopausal woman with melorheostosis of the right lower limb and with a fracture of the melorheostosis-free T11 vertebral. Methodology: Melorheostotic lesions were evaluated by plain radiography, magnetic resonance of the right lower limb, and whole-body bone scintigraphy. Dual X-ray absorptiometry, trabecular bone score, and quantitative computed tomography were performed to investigate unaffected bone sites. Biochemical assessment of bone metabolism was obtained. Results: Dual X-ray absorptiometry was indicative of normal mineralization at femoral sites and osteopenia at lumbar spine (T-score −1.1), which was confirmed by spinal quantitative computed tomography (volumetric bone mineral density 89 mg/cm3). Trabecular bone score suggested only mildly altered bone microarchitecture (1.304, normal values >1.350). Bone markers were consistent with high bone turnover. Causes of secondary osteoporosis or alterations in bone metabolism were excluded. Zoledronic acid induced a reduction in bone turnover markers after 6 months without significant changes in clinical features. Conclusions: Fragility fractures at apparently unaffected sites may occur in adults with melorheostosis, in absence of significant demineralization diagnosed by dual X-ray absorptiometry, trabecular bone score, and quantitative computed tomography, which may underestimate the fracture risk in this set of patients. Treatment with zoledronate could be considered also to prevent fragility fractures.

Background: Recently, a lateral-view dual X-ray absorptiometry (DXA) scanning method for measuring leg total, lean, and fat masses demonstrated accuracy vs the standard whole-body frontal DXA scanning view on the GE Lunar iDXA. The current study examined the lateral scanning method's agreement using a Hologic Horizon A DXA scanner. Methodology: Thirty healthy college-age participants (16 female; Xage = 21.5 ± 1.7 yr) received 3 DXA scans (1 whole-body, 2 lateral leg scans) to quantify leg composition in the frontal and lateral plane. To mark regions of interest for postscan analysis, metallic markers were placed at 60% of the length above and below each leg's lateral epicondyle. Using lateral subject positioning, leg composition was measured with participants lying on their right and left sides. Paired t tests examined the lateral DXA scanning method's agreement when quantifying total, fat, and lean masses, bone mineral content, and bone mineral density compared to measurements of equal area in the whole-body frontal scanning view. Results: Comparisons of frontal and lateral view DXA scan measurements for right leg total mass (7.12 ± 0.91kg vs 6.39 ± 0.85kg), fat mass (1.70 ± 0.44kg vs 1.36 ± 0.33kg), lean mass (5.14 ± 1.05kg vs 4.77 ± 0.92kg), bone mineral content (0.28 ± 0.06kg vs 0.23 ± 0.05kg), and bone mineral density (1.39 ± 0.14g/cm2vs 1.36 ± 0.15g/cm2), respectively, were significantly different (p

Raymond-Pope, CJ, Dengel, DR, Fitzgerald, JS, and Bosch, TA. Association of compartmental leg lean mass measured by dual X-ray absorptiometry with force production. J Strength Cond Res 34(6): 1690-1699, 2020-We recently reported a novel method for measuring upper leg anterior/posterior compartmental composition. The purpose of this study was to determine the association of this method with measures of muscle-specific and explosive strength and to compare this method with traditional dual energy X-ray absorptiometry (DXA) measurements of total and upper leg masses. We hypothesize this method will be related to muscle-specific strength measured by isokinetic dynamometry and explosive strength measured by jump mechanography. Nineteen NCAA Division I college athletes (10 women; age = 20.4 ± 1.4 years; height = 1.8 ± 0.1 m; body mass = 73.8 ± 17.0 kg) underwent 3 DXA scans (1 total body, 2 lateral) and knee extension/flexion strength assessment using isokinetic dynamometry at 3 velocities (60, 120, and 180°·s). A subset of 10 participants also completed a squat jump on a force platform on a different day. Pearson correlations compared 3 separate lean soft-tissue mass (LSTM) regions of interest (total leg, upper leg, and compartmental leg) with (a) isokinetic peak torque and (b) squat jump height, peak force, and peak and average rate of force development. Compartmental leg LSTM demonstrated similar correlations (r = 0.437-0.835) with peak torque in comparison with total leg (r = 0.463-0.803) and upper leg (r = 0.449-0.795) LSTM. Summed right and left total leg (r = 0.830-0.940), total upper leg (r = 0.824-0.953), and anterior (r = 0.582-0.798) and posterior (r = 0.750-0.951) compartmental leg LSTM demonstrated moderate-to-strong correlations with all squat jump variables, particularly jump height (p < 0.05). The lateral segmentation DXA scanning method demonstrated feasibility in assessing compartmental leg LSTM in relation with isokinetic and squat jump measurements-important outcomes when examining an athlete's response to training and rehabilitation.

The purpose of the present study was to generate normative values for total and regional body composition in male and female Division 1 collegiate track and field athletes using dual X-ray absorptiometry. We also sought to examine body composition by event and sex. Data were used from the Consortium of College Athlete Research group. A total of 590 (male [M]/female [F] = 274/316) athletes had their height, weight, total and regional fat mass (FM), lean mass, and bone mineral density (BMD) measured. Athletes were classified into 1 of 7 categories: Jumps (M/F = 28/30); Long Distance (M/F = 104/110), Middle Distance (M/F = 27/24), Multievent (M/F = 11/9), Pole Vault (M/F = 21/27), Sprints (M/F = 54/96), and Throws (M/F = 29/20). Total and regional differences between events and sex were assessed by analysis of variance. Except for male and female throwers, all other track and field athletes' mean percent body fat (M: 10.3%-12.6%, F: 17.5%-21.6%) and visceral FM (500 g) was low, but in a healthy range. As expected, throwers had significantly (p0.05) higher total and regional FM and lean mass than other events. In addition, male (1.55 ± 0.11 g/cm

Maximum isometric handgrip strength (MIHS) is a relevant parameter for judo performance and is related to health. Understanding the association between MIHS and MIHS relative (MIHSrel) and the absolute lean mass of the arm (LMarm) and the percentage of body fat (%BF) can provide important information for performance and health. The study aimed to investigate the correlation between MIHS and MIHSrel with the LMarm and the %BF of young judokas (sub-19, 15 males and 14 females). MIHS was measured using a multipurpose digital dynamometer with a load cell for computer. Body composition was measured by dual-energy X-ray absorptiometry (DXA). The correlation between MIHS, MIHSrel with LMarm and %BF was verified through Pearson’s correlation, with a significance level of p < 0.05. Correlation between MIHSrel and %BF was very high only in female judokas for both arms (right, r = −0.76; left, r = −0.75). Correlations between LMarm and MIHS of the right and left arms ranged from very high to almost perfect for both sexes (r = 0.74 to 0.94). These results highlight the importance of strengthening the arms in young judokas, and controlling body fat for performance and health, especially in female judokas.

Purpose: Dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) permits quantification of visceral adipose tissue (VAT). However, DXA has not been validated against MRI in persons with chronic spinal cord injury (SCI). A predictive equation was generated from the measurement of VAT by MRI, a “gold” standard to quantitate VAT, compared to that of DXA, a method with several practical advantages. Method: DXA and MRI scans were performed in 27 participants with SCI. MRI multiaxial images were captured for VAT analysis. DXA-VAT was quantified at the android region (DXA-VATANDROID-VOL) using enCore software. Android regions of DXA and MRI were matched using android height. Volumes of multiaxial MRI-VAT and subcutaneous adipose tissue (SAT) were quantified for the android region (MRI-VATANDROID-VOL, MRI-SATANDROID-VOL) and total trunk (MRI-VATANDROID-VOL). Linear regression analysis was used to establish the proposed predication equations. The prediction equations were then applied to an independent sample that consisted of 98 participants with SCI. Bland-Altman analysis was used to determine the limits of agreement. Results: DXA-VATANDROID-VOL predicted 92% of the variance in MRI-VATANDROID-VOL (SEE = 252.5, p

Objective: The objective of this study was to investigate the diagnostic discordance of osteoporosis by quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA) in Chinese elderly men. Methods: A total of 313 males older than 60 years, who underwent both spinal QCT and lumbar spine and hip DXA in our department, were included. The diagnostic criteria established by the World Health Organisation in 1994 were used for DXA to diagnose osteoporosis, and the criteria recommended by the International Society of Clinical Densitometry were used for QCT. The osteoporosis detection rate by the two techniques was calculated, and the difference was compared. The minor discordance was considered present when the different diagnostic classes between the two techniques were adjacent. Major discordance was present when the diagnosis by one technique was osteoporosis and the other was normal. The computed tomography images were reviewed by radiologists to assess whether vertebral fracture, aorta calcification or degeneration was present. Results: In the 313 participants (mean age, 79.6 ± 7.2 years), the osteoporosis detection rate was 10.9% for DXA (lumbar spine and hip) and 45.1% for QCT, a significant difference (p

The body composition phenotype of an athlete displays the complex interaction among genotype, physiological and metabolic demands of a sport, diet, and physical training. Observational studies dominate the literature and describe the sport-specific physique characteristics (size, shape, and composition) of adult athletes by gender and levels of competition. Limited data reveal how body composition measurements can benefit an athlete. Thus, the objective is to identify purposeful measurements of body composition, notably fat and lean muscle masses, and determine their impact on the health and performance of athletes. Areas of interest include relationships among total and regional body composition measurements, muscle function, sport-specific performance, risk of injury, return to sport after injury, and identification of activity-induced fluid shifts. Discussion includes the application of specific uses of dual X-ray absorptiometry and bioelectrical impedance including an emphasis on the need to minimize measurement errors and standardize protocols, and highlights opportunities for future research. This focus on functional body composition can benefit the health and optimize the performance of an athlete.

Introduction: Osteoporosis is increasingly becoming a public health concern especially in the ageing population. Fractures related to osteoporosis are an important cause for pain and disability. Most common methods used for measuring Bone Mineral Density (BMD) include Dual-energy X-ray Absorptiometry (DXA) and Quantitative Computed Tomography (QCT). There is a substantial increase in the number of patients undergoing a primary Computed Tomography (CT) study of the abdomen for various clinical reasons. Use of QCT for measurement of BMD helps to identify the high risk patients for osteoporotic fractures. This also reduces the need for any additional imaging, radiation exposure, cost or patient time. Aim: To compare the BMD values between pre-menopausal and post-menopausal females using QCT. Materials and Methods: This was a retrospective cross- sectional study. A total of 40 patients with 20 patients each in pre- menopausal and post-menopausal group who had undergone routine abdominal CT for various clinical indications unrelated to bone disorders were evaluated. Regions of Interest (ROIs) were measured on the axial images at T12 through L5 vertebrae at three locations, one over the trabecular part of vertebrae, one on the posterior paraspinal muscles and the third ROI over the subcutaneous fat. BMD was calculated by using phantom less QCT software of the Philips CT workstation. Both t-score and BMD values were automatically generated by the software. The thresholds for spinal trabecular BMD were 45 years, the mean BMD observed was 129.77±48.92 mg/cc. The mean t-score values for pre-menopausal and post-menopausal women were -0.67±0.88 and -1.57±1.58, respectively. Comparison of t-score (p

The objective of this experiment was to evaluate the growth performance and bone mineral content (BMC) of nursery pigs in response to increasing total calcium (Ca) to available phosphorus (aP) ratios in diets containing phytase (250 FTU/kg; Natuphos E, BASF, Florham Park, NJ). A total of 480 nursery pigs (body weight (BW) = 5.7 ± 0.6 kg) with 10 pigs per pen and 7 pens per treatment (6 pens fed 2.75:1 diet) were allotted to seven treatments consisting of increasing ratios of calcium to available phosphorus (Ca:aP): 1.25, 1.50, 1.75, 2.00, 2.25, 2.50, and 2.75. From day −7 to 0, pigs were fed a common diet. They were then fed the treatment diets during two experimental phases from day 1 to 14 and 15 to 28, respectively. Available P was formulated to 0.33% and 0.27% (approximately 90% of requirement) in dietary phases 1 and 2, respectively. BW, average daily gain (ADG), average daily feed intake (ADFI), and gain-to-feed ratio (G:F) were determined. BMC of the femur was measured on day 28 on one pig per pen using dual x-ray absorptiometry. Data were analyzed as a linear mixed model using PROC MIXED (SAS, 9.3). Orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing the Ca:aP. Over the 28-d experimental period, increasing Ca:aP resulted in a linear decrease in ADG (353, 338, 328, 304, 317, 291, and 280 g/d; P < 0.01), ADFI (539, 528, 528, 500, 533, 512, and 489 g/d; P < 0.05), and G:F (0.68, 0.66, 0.64, 0.62, 0.61, 0.59, and 0.58; P < 0.01). Increasing Ca:aP also resulted in decreased BW on days 14 and 28 (P < 0.01). The BMC of the femur decreased with increasing Ca:aP (6.2, 6.3, 5.7, 5.9, 5.5, 5.6, and 5.3 g; P < 0.05). Regression analysis explained the impact of Ca:aP as follows on ADG (ADG [g/d] = 339 − 36x; r2 = 0.81), G:F (G:F = 0.61 – 0.03x; r2 = 0.72), and BMC (BMC [g] = 6.4 – 0.27x; r2 = 0.43), where x is the Ca:aP. In conclusion, all outcomes indicated that any level of calcium above the minimum used in this experiment impaired growth performance and skeletal development. Further research using even lower levels of dietary Ca is warranted.

Reduced bone mass with or without fragility fractures is a common feature of mastocytosis, particularly in adult males. However, bone mineral density does not account for all the fragility fractures, being a part of them attributable to impairment in bone quality. Aim of this study is to assess the usefulness of DXA-derived geometry and structural indexes in the assessment of bone status in mastocytosis. Ninety-six consecutive patients (46 women and 50 men) affected by cutaneous (CM) or systemic (SM) mastocytosis were studied. Mean age (± SD) was 53.3 ± 14.23. Spine lateral X-rays for Genant's scale, DXA for lumbar (L) and femoral (F) bone mineral density (BMD), bone strain index (BSI), lumbar trabecular bone score (TBS), and hip structural analysis (HSA) were performed. Among the laboratory variables, data of serum tryptase were reported. Tryptase was higher in SM (p = 0.035), inversely correlated with LBMD (r = − 0.232; p = 0.022) and TBS (r = − 0.280; p = 0.005), and directly with L-BSI (r = 0.276; p = 0.006). L-BSI remained statistically significant (p = 0.006; adjusted R2 = 0.101) together with mastocytosis (SM or CM: p = 0.034) in the multivariate regression model with tryptase as dependent variable, being LBMD and TBS not statistically significant (p = 0.887, and p = 0.245, respectively). Tryptase increased about 22 units for each unit increase of L-BSI and about 18 units for SM against CM. L-BSI was lower (p = 0.012), while FN-BSI and FT-BSI were higher in women (p

Background Quantification of skeletal muscle mass is mandatory for diagnosing sarcopenia, a highly prevalent geriatric syndrome. While dual energy X-ray absorptiometry (DXA) is the reference method in a clinical context, bioimpedance analysis (BIA) is more readily applicable on a broad scale. Recently BIA equations for the prediction of appendicular skeletal muscle mass in higher age groups have been published, but data on their performance in geriatric inpatients are lacking. Methods In 144 geriatric inpatients (86 women and 58 men, mean age 80.7 ± 5.6 years) appendicular skeletal muscle mass was predicted by 4 different BIA equations and measured by DXA. Results were compared by linear regression analysis and Bland Altmann plots. The agreement with DXA in classifying subjects to have normal or reduced muscle mass was calculated for the BIA based approaches. Results The 4 BIA equations showed only minor differences in regression analysis, but major differences in mean error (range −0.98 kg to + 0.19 kg in women and −2.47 kg to −0.58 kg in men). Considering regression parameters and mean error, the equation of Scafoglieri et al. performed best, resulting in an agreement with DXA of more than 83%. Sensitivity to detect subjects with reduced muscle mass was Conclusion The BIA equation of Scafoglieri et al. performs best in geriatric inpatients, with more than 83% of subjects classified correctly as having normal or reduced muscle mass compared to DXA. Low sensitivity to detect subjects with reduced muscle mass in geriatric inpatients remains a limitation of BIA.

Introduction: Dual X-Ray Absorptiometry (DXA) is the gold standard for the diagnosis of osteoporosis, but it has its pitfalls. The OsteoSee @Clinic is a novel portable and user-friendly system, which uses parametric Electrical Impedance Tomography (pEIT), being developed to allow screening and diagnosis of osteoporosis at the primary care clinic Aim: To test the new system and compare its results to those of the DXA system. Methods and Subjects: This prospective study was conducted between 01/01/2019 and 01/06/2019. Subjects who presented for a routine DXA scan (lumbar spine and proximal femur with Lunar Prodigy GE healthcare system) were enrolled. After signing an informed consent form, they were scanned with the OsteoSee @Clinic system (OsteoSee Ltd., Israel) using 5 electrodes placed around the left distal forearm and around the pelvis. Results: OsteoSee @Clinic data were compared to DXA total hip bone mineral density (BMD). Correlations were examined between pEIT-index of the pelvis versus DXA total hip BMD. Sensitivity and specificity were calculated according to the diagnosis obtained by DXA based on the total hip T-score. An analysis based on 182 subjects (35 healthy, 115 osteopenia, 32 osteoporosis) scanned on the wrist showed an R-value of 0.795 (p-value < 0.001) representing the correlation between the pEIT-wrist index and DXA results. From the ROC plot, we obtained a sensitivity of 84% and specificity of 71% to diagnose osteoporotic vs osteopenic & normal subjects, and a sensitivity of 82% and specificity of 86% for identifying osteopenic & osteoporotic vs normal subjects. An analysis of 98 subjects (17 healthy, 66 osteopenic, 15 osteoporosis) scanned on the pelvis showed an R-value of 0.740 (p-value < 0.001), representing the correlation between the pEIT-pelvis index and DXA BMD. From the ROC plot, we obtained a sensitivity of 80% and specificity of 81% to diagnose osteoporotic vs osteopenic & normal subjects, and a sensitivity of 70% and specificity of 76% for identifying osteopenic & osteoporotic Vs normal subjects. Conclusions: The OsteoSee @Clinic system results correlate well with DXA measurements, especially when taking into account clinical interpolations. Sensitivity and specificity values indicate that the OsteoSee @Clinic system can provide screening and diagnosis of osteoporosis. With the DXA system being costly to operate and inaccessible to many patients, the OsteoSee @Clinic system may address the unmet need for diagnosing and treating osteoporosis, and offer an alternative for a broader screening of the population at risk of fractures. Disclosure: The study was funded by OsteoSee Ltd., Israel

Lipoedema is painful nodular subcutaneous adipose tissue (SAT) on legs and arms of women sparing the trunk. People with Dercum disease (DD) have painful SAT masses. Lipoedema and DD fat resists loss by diet and exercise. Treatments other than surgery are needed. Six women with lipoedema and one with DD underwent twelve 90-min sessions over 4 weeks. Body composition by dual X-ray absorptiometry scan, leg volume, weight, pain, bioimpedance, tissue size by caliper and ultrasound were analysed before and after SAT therapy by paired t-tests. There was a significant decrease from baseline to end of treatment in weight, 87.6 ± 21 to 86.1 ± 20.5 kg (P = 0.03), leg fat mass 17.8 ± 7.7 to 17.4 ± 7.6 kg (P = 0.008), total leg volume 12.9 ± 4 to 12 ± 3.5 L (P = 0.007), six of 20 calliper sites and tissue oedema. Pain scores did not change significantly. By ultrasound, six women had 22 hyperechoic masses in leg fat that resolved after treatment; five women developed seven new masses. Fascia improved by ultrasound after treatment. SAT therapy reduced amount and structure of fat in women with lipoedema and Dercum disease; studies are needed to compare SAT therapy to other therapies.

Improper positioning is one of the factors that can lead to incorrect bone mineral density (BMD) results. This study aimed to assess the frequencies of erroneous positioning during three periods: before retraining of the technologists (BR), after retraining (AR), and at the current timepoint 8 years after retraining (C). The BMD images of the first 150 consecutive patients who underwent DXA of the lumbar spine and hip during each of the three periods were retrospectively reviewed. Patients were excluded if they had severe scoliosis, rendering proper positioning impossible. Each BMD image was assessed by an International Society of Clinical Densitometry certified clinical densitometrist who was blinded to the date of the initial examination. For the lumbar spine in the BR group, the criteria frequently not met were inclusion of both iliac crests (33.8%), straightness (30.3%), and midline positioning (20.4%); the respective frequencies were significantly reduced to 0.8%-5.6%, 2.1%-3.0%, and 0%-2.8% in the AR and C groups (p < 0.05). For the hip in the BR group, the criteria frequently not met were straightness (52.8%) and internal rotation (21.8%); the respective frequencies were significantly reduced to 0%-4.2% and 8.3%-8.4% in the AR and C groups (p < 0.05). Overall improper positioning in the BR group was 49.3% and 57.3% at the lumbar spine and the hip, respectively; the respective frequencies were reduced to 9.3% and 12.7% in the AR group, and to 2.7% and 7.3% in the C group. The least significant change values for the lumbar spine, femoral neck, and total hip also became smaller after retraining. Retraining the technologists improved patient positioning, as evidenced by the decreased frequencies of erroneous positioning and the improved least significant change values after the retraining.

Background and Aims The aim of this study was to compare the accuracy of measurements of body composition made using dual X-ray absorptiometry (DXA), analysis of computed tomography (CT) scans at the L3 vertebral level and bioelectrical impedance analysis (BIA). Methods DXA, CT and BIA were performed in 47 patients recruited from two clinical trials investigating metabolic changes associated with major abdominal surgery or neoadjuvant chemotherapy (NAC) for oesophagogastric cancer. DXA was performed in the week before surgery, and before and after commencement of NAC. BIA was performed at the same time points and used with standard equations to calculate fat free mass (FFM). Analysis of CT scans performed within three months of the study was used to estimate FFM and fat mass (FM). Results There was good correlation between FM on DXA and CT (r 2 =0.6632, p 2 =0.7634, p 2 =0.6275, p 2 =0.2742, p Conclusion Although a systematic error underestimating fat free mass was demonstrated with BIA, it may be a useful modality to quantify body composition in the clinical situation.

Neste trabalho, pretende-se investigar a fragilidade óssea cortical no fémur com a idade (à morte) e a sua associação ao sexo e à densidade mineral óssea. Os parâmetros radiogramétricos do fémur e a densidade mineral óssea no fémur proximal foram avaliados numa amostra de indivíduos adultos (N=98) da Coleção de Esqueletos Identificados da Universidade de Coimbra (Portugal). A largura total da diáfise (LTD), o índice cortical do fémur (FEMCI) e a densidade mineral óssea (DMO) são significativamente maiores nos homens, enquanto a largura medular (LM) não é estatisticamente diferente entre os sexos. Os parâmetros corticais da diáfise do fémur encontram-se associados à idade apenas nas mulheres; por seu lado, a DMO declina com a idade em ambos os sexos. A avaliação do osso cortical do fémur revela trajetórias sexuais específicas de perda óssea endosteal e aposição periosteal, que têm origem em diferenças sexuais no grau e padrão de perda de osso, bem como no tamanho ósseo. Nas mulheres, a perda endocortical de osso aumenta com a idade, particularmente nos anos peri- e pós-menopáusicos, desacelerando mais tarde. De forma concomitante, a acreção de osso na superfície subperiosteal persiste durante a vida adulta – equilibrando parcialmente a fragilidade óssea nas mulheres. A resistência óssea a meio da diáfise do fémur parece ser preservada durante grande parte da vida em ambos os sexos.

Objectives: Body composition is important to rugby league coaches because, in concert with other factors such as muscle and tendon properties and neurophysiology, composition values provide a general indication of strength and power and an ability to absorb high impacts. We compared whole-body and regional body composition values of junior representative (under 16 years, 18 years) and senior professional (1st grade) National Rugby league (NRL) players using Dual X-ray Absorptiometry (DXA). Methods: One hundred and forty-two junior representative and senior 1st grade rugby league players completed a whole-body DXA scan. Juniors comprised U/16 (mean age 15.9 ± 0.8 years, n = 25), and U/18 (17.9 ± 0.6 years, n = 21) state-level representative players while 1st grade players (25.3 ± 2.3 years, n = 96) were drawn from three NRL clubs. Results: Junior representative players were lighter in body mass and shorter in stature compared to 1st grade players. Despite greater lean tissue mass (LTM) in 1st grade players, there were no between-group differences in fat mass (FM) at whole-body or regional sites. Conclusions: When comparing body composition values between junior representative players to 1st grade players’ results show that senior players have greater LTM but do not differ in FM relative to junior players. Findings suggest that junior training programs should emphasise developmentally-appropriate resistance training with a continuation of current practices to maintain FM.

Aim of this paper was to assess the discrimination power of a novel ultrasound (US) parameter, called the Fragility Score (F.S.), in the early identification of subjects prone to osteoporotic fractures. A total of 102 female patients were recruited: 49 with a recent osteoporotic fracture (“frail” subjects), 53 were controls without fracture history (“non-frail” subjects). All the patients underwent a spinal DXA (dual X-ray absorptiometry) and an abdominal US scan of lumbar vertebrae. Acquired US data were analyzed by a novel algorithm, which calculated the F.S. through spectral and statistical analyses involving both echographic images and corresponding “raw” signals. F.S. showed a good performance in discriminating “frail” from “non-frail” subjects (sensitivity = 76%, specificity = 68%), resulting even slightly more effective than DXA-measured BMD (sensitivity = 73%, specificity = 66%). This methodology has a potential to become an effective tool for the early identification, and timely treatment, of “frail” subjects.

The aim of this study was to retrospectively interpret body composition in various wheelchair athletes. In total, 69 athletes (mean ± standard deviation; age 33 ± 11 years; body mass 65.1 ± 14.8 kg; height 169.9 ± 14.9 cm and time since injury 19 ± 11 years) from different national teams in wheelchair sports underwent a dual X-ray absorptiometry (DXA) measurement during the yearly medical check-up. The data showed a significant difference between total fat and total fat-free mass between male (fat mass: 15.1 ± 7.6 kg; fat-free mass: 51.8 ± 9.3 kg) and female (fat mass: 19.4 ± 7.8 kg; fat-free mass: 36.8 ± 7.6 kg) athletes (p = 0.032, p < 0.001). In contrast, no significant difference (p = 0.16, p = 0.07) in fat and fat-free mass between paraplegic, tetraplegic and non-SCI athletes was found. Comparing different sports, the lowest fat mass was found in paracycling athletes whereas curling game players showed the highest total fat mass. Basketball game players showed the highest fat-free mass (fat-free mass: 54.8 ± 10.1 kg). In tetraplegic athletes, difference in fat-free mass between left and right arms correlated with the upper extremity motor score. For the interpretation of the data it seems to be crucial, that many different parameters (i.e., gender, motor level of the injury) are taken into consideration in wheelchair athletes.

Although several progresses have been achieved in this field, male osteoporosis remains an underdiagnosed and undertreated condition.

OBJECTIVES To compare total and regional body fat percent (BF%) measurements obtained using a handheld electrical impedance myography (EIM) device in comparison to BF% measured by dual X-ray absorptiometry (DXA). METHODS Sixty-nine male and female (33 males/36 females; age = 21.9 ± 2.0 years, body mass index = 24.5 ± 3.6 kg/m2 ) college-age individuals participated in this study. Each participant's total and regional (ie, upper arms, upper legs, trunk) BF% was estimated using EIM and DXA. Metallic markers were used to delineate regional boundaries for analysis, including upper arms (biceps/triceps), upper legs (quadriceps/hamstrings), and trunk (abdominal region/low back region). Paired t-tests assessed the accuracy of BF% values estimated from EIM in comparison to BF% measured by DXA. RESULTS Observations revealed EIM reported significantly lower BF% for upper left arm (P

Background Obesity in the United States is a serious and preventable health concern. Previous research suggests that habitual short sleep may influence obesity-risk behaviors, such as increased caloric intake, decreased physical activity and increased engagement in sedentary activities (e.g., media consumption, computer usage). Given that existing longitudinal research studies have methodological concerns preventing conclusive interpretations, Project STARLIT was designed to address these limitations and identify future intervention targets. Methods A sample of young adults (n = 300) will be recruited during the summer prior to entering college. Participants will be screened for eligibility requirements prior to the inclusion in the Time 1 assessment though phone and in-person interviews. Once enrolled, participants will complete four assessments over a two year period (i.e., approximately 8, 16 and 24 months after Time 1). Each assessment will consist of one week of data collection including both objective (i.e., habitual sleep, physical activity, body fat composition) and subjective (i.e., sleep diary, 24-h food recall, technology use, and sleep-related beliefs/behaviors) measures. Discussion Project STARLIT is designed to address methodological concerns of previous research. In addition to clarifying the relationship between habitual short sleep and weight gain among young adults, the proposed study will identify problematic obesity risk behaviors associated with habitual short sleep (e.g., increased caloric intake, physical/sedentary activity). The results will identify prevention or intervention targets related to obesity risk. Trial registration ClinicalTrials.gov NCT04100967, 9/23/19, Retrospectively registered.

Skeletal muscle is highly adaptable and has consistently been shown to morphologically respond to exercise training. Skeletal muscle growth during periods of resistance training has traditionally been referred to as skeletal muscle hypertrophy, and this manifests as increases in muscle mass, muscle thickness, muscle area, muscle volume, and muscle fiber cross-sectional area (fCSA). Delicate electron microscopy and biochemical techniques have also been used to demonstrate that resistance exercise promotes ultrastructural adaptations within muscle fibers. Decades of research in this area of exercise physiology have promulgated a widespread hypothetical model of training-induced skeletal muscle hypertrophy; specifically, fCSA increases are accompanied by proportional increases in myofibrillar protein, leading to an expansion in the number of sarcomeres in parallel and/or an increase in myofibril number. However, there is ample evidence to suggest that myofibrillar protein concentration may be diluted through sarcoplasmic expansion as fCSA increases occur. Furthermore, and perhaps more problematic, are numerous investigations reporting that pre-to-post training change scores in macroscopic, microscopic, and molecular variables supporting this model are often poorly associated with one another. The current review first provides a brief description of skeletal muscle composition and structure. We then provide a historical overview of muscle hypertrophy assessment. Next, current-day methods commonly used to assess skeletal muscle hypertrophy at the biochemical, ultramicroscopic, microscopic, macroscopic, and whole-body levels in response to training are examined. Data from our laboratory, and others, demonstrating correlations (or the lack thereof) between these variables are also presented, and reasons for comparative discrepancies are discussed with particular attention directed to studies reporting ultrastructural and muscle protein concentration alterations. Finally, we critically evaluate the biological construct of skeletal muscle hypertrophy, propose potential operational definitions, and provide suggestions for consideration in hopes of guiding future research in this area.

Background: Dual energy X-ray absorptiometry (DXA) is a well-regarded device for primarilymeasuring bone mineral density (BMD) and body composition. [...]

Background Cystic fibrosis (CF) is characterized by changes in fat mass and lean body mass that may have important prognostic value. We aim to appraise the type and frequency of application of body composition (BC) methods in child and adult patients with CF. Methods We used 4 databases (Embase, PubMed, Scopus, and Web of Science) to perform the literature search. The search was conducted from January 2017 to February 2017. Two independent reviewers selected articles based on titles and abstracts to check eligibility for inclusion. All study designs or types of articles (abstract, full text) were considered. Results Eighty-four full-text articles and 40 studies presented only as abstracts were selected. Sixty-four studies included children and adolescents (age range of 0.1-18 years), and 41 studies recruited adults (range of 18-57 years); 13 studies included both age groups. Dual-energy X-ray absorptiometry (DXA) was used in 56 studies (33.9%), and bioelectric impedance analysis (BIA) was used in 12 studies (9.7%), whereas 38 studies (30.6%) combined different methods (up to 5 different methods) to assess BC. Conclusions The results show a large variability in the application of BC methods in patients with CF that makes the comparison between studies difficult. The only methods with a sufficient body of literature are DXA and BIA.

Introduction Bone decalcification is a necessary preprocessing step in histological and anatomical studies. Several solutions for decalcification with different claimed times for full decalcification are commercially available. Current literature lacks direct, quantitative measurement of calcium hydrocyapatite degradation during decalcification to compare different solutions. Therefore, the aim of this study was to test the performance of three different decalcification solutions in human bone by direct measurement of calcium hydroxyapatite using dual-X-ray-absorptiometry (DEXA) and volumetric computed tomography (CT). Methods Four femur slices were acquired from the proximal femur of a 76-year-old body donor. The slices were submerged in formaldehyde (control), EDTA, Osteosoft (Merck, Darmstadt, Germany) and “Rapid Bone Decalcifier” (RBD) (American MasterTech Scientific, Lodi, USA). Consecutive DEXA and CT scans were performed at 2 h, 4 h, 8 h, 11 h, 20 h, 44 h and 77 h after solutions were added. Besides the calcium hydroxyapatite concentration, the bone volume was measured each time. Results Fastest decline in volume was seen in the RBD probe. Further, RBD was the only solution, being able to fully decalcify the bone slice after 77 h. Although a steady decline in volume and hydroxyapatite concentration was seen for EDTA and Osteosoft as well, both were not able to decalcify the slices. Conclusion Overall, the purely qualititve acquired literature data on bone decalcifiers was verified by our quantitative data for human, cortical-rich bones. Hydrochloric-acid based solutions seem to be preferable in order to rapidly dissolve the calcium hydroxyapatite.

Background: Trampolining is a form of gymnastics that has increased in popularity over the last decade and due to its concurrence with the formative years of bone development, it may have an important impact on bone health. However, bone density, microarchitecture, and bone strength of competitive trampolinists have not been explored. Therefore, the purpose of this cross-sectional study was to investigate the relationship between trampolining participation and (1) bone density, area, and microarchitecture; and (2) estimated bone strength and the role of muscle and impact loading in young female adults. Methods: We recruited 29 female participants aged 16–29 years for this study (n = 14 trampolinists; n = 15 controls). Skeletal parameters were assessed using dual X-ray absorptiometry, high-resolution peripheral quantitative computed tomography (HR-pQCT), and finite element analysis (FEA). Muscle strength was measured using dynamometers. Results: Trampolinists had higher bone density at the hip and spine, greater trabecular density and thicker trabeculae at the tibia, as well as larger bones at both the tibia and radius than controls (p

Trabecular bone score (TBS), which has been shown to discriminate patients with fractures from healthy individuals, decreases with age. This study was conducted to derive an age-adjusted normative TBS curve for each gender aged 30–80 + years to serve as reference data for Thai males and females. A cross-sectional study was conducted among employees from the Electricity Generating Authority of Thailand cohorts, after excluding those with conditions potentially affecting bone metabolism and analysis. The values of TBS at L1–L4 vertebrae were analyzed using a commercial software. Age-adjusted TBS curves were constructed using segmental linear regression analysis for each gender. Additional analysis was also performed on TBS with age, body mass index, and body mineral density (BMD) at L1–L4 vertebrae as covariates. A database of 848 healthy subjects (341 females and 507 males) aged 30–80+ years was created. The BMDs of both male and female subjects in the youngest decade were not statistically different from previous reports (p = 0.31 and 0.22 for females and males, respectively). In this age group, the mean TBS was higher in females, albeit not statistically significant (p = 0.12). Between the ages of 30–80+ years, female and male TBS dropped by 19.8% (0.40% per year) and 10.1% (0.20% per year), respectively. The association with TBS was weak for body mass index and moderate for BMD (coefficients of about −0.01 and 0.4–0.5, respectively). The age-adjusted reference curves for healthy Thai females and males aged 30–80+ years have been established.

The aim of this study was to compare whole and segmental body composition and bone mineral density of collegiate American football players by playing positions. Forty collegiate American football players voluntarily participated in this study. Participants were categorized by playing positions into one of five categories i.e., defensive linemen, offensive linemen, defensive secondary players, offensive secondary players and receivers. Whole body composition and bone mineral density were measured by dual x-ray absorptiometry. Offensive and defensive linemen had higher body mass, a body mass index, lean mass and a fat mass index compared to the remaining three positions and a higher lean mass index compared to offensive secondary players and receivers. Offensive linemen had a higher body fat percentage and lower values of upper to lower lean mass than offensive and defensive secondary players and receivers, and higher total mass to the lean mass ratio and fat mass to the lean mass ratio compared to the other players. Offensive linemen had a higher fat mass index and fat mass to the lean mass ratio than defensive linemen. However, in all other measures they were similar. Offensive and defensive secondary players and receivers were similar with respect to the measured variables. Bone mineral density of the players was within the normal range and no difference in lean mass was observed between the legs. In conclusion, findings of this study showed that the total and segmental body composition profile of collegiate American football players reflected the demands of particular playing positions.

It is important to understand the timing of the maximum increase of forearm-hand inertia value and lean body mass (LBM) of the shoulder girdle musculature when elbow injury frequently occurs. This study aimed to clarify the discrepancies of those in youth baseball players. Forty-three male baseball players (8- to 14-years-old) participated in this study. The forearm-hand inertia value and LBM of the shoulder girdle musculature were calculated using dual-energy X-ray absorptiometry (DXA). A cubic spline fit was applied to the annual increase forearm-hand inertia value and LBM of the shoulder girdle musculature for each chronological age and years from peak height velocity (PHV) age. As a result of cubic splines fitting, the peak timing for forearm-hand inertia value and LBM of the shoulder girdle musculature was 12.42 and 12.75 years in chronological age, &minus, 0.66 and &minus, 0.11 years in PHV age. Therefore, the peak timing of forearm-hand inertia value was about 4 months earlier in chronological age and half a year earlier in PHV age than LBM of the shoulder girdle musculature. Acquiring sufficient shoulder girdle musculature during the period when the growth of the shoulder girdle musculature cannot catch up with forearm-hand inertial value is necessary to reduce the elbow load while throwing.

Objective To investigate the associations among visceral adiposity index (VAI), lipid accumulation product (LAP), body fat percentage (%), and android/gynoid ratio (A/G ratio) in women with polycystic ovary syndrome (PCOS) and verify if the parameters representative of visceral obesity correlate with and exhibit the same frequency as body composition variables; anthropometric indices; and metabolic, hormonal, and inflammatory parameters. Subjects and methods This was a cross-sectional study that included 94 women with PCOS. Hormonal, metabolic, and inflammatory parameters were analyzed in all women. Free androgen index (FAI) and homeostasis model assessment (HOMA-IR), as well as LAP, VAI, and anthropometric indices, were calculated. The regions of interest (ROIs) in body composition and body composition indices were evaluated using a dual X-ray absorptiometry (DXA). Overall, 32 variables were selected as markers of body fat distribution. Results Among the 32 markers evaluated, 29 correlated with LAP, whereas 25 correlated with VAI, 19 with body fat (%), and 30 with A/G ratio. Additionally, some markers correlated with the four adiposity indices evaluated: ROIs, except for total mass and leg fat (%); body composition (body mass index, waist circumference, and hip circumference) indices; fasting insulin; and C-reactive protein. Conclusion LAP and VAI may be sensitive measures for screening and preventing metabolic syndrome and insulin resistance in PCOS, with LAP being more sensitive than VAI, and the A/G ratio may be more sensitive than body fat percentage.

Supplemental Digital Content is available in the text, Bioelectrical impedance analysis (BIA) is currently the most commonly used method in clinical practice to measure body composition. However, the bioelectrical impedance analyzer is not designed according to different countries, races, and elderly populations. Because different races may have different body compositions, a prediction model for the elderly population in Taiwan should be developed to avoid population bias, thereby improving the accuracy of community evaluation surveys. Dual energy X-ray absorptiometry (DXA) was used as a standard method for comparison, and impedance analysis was used for the development of a highly accurate predictive model that is suitable for assessing the body composition of elderly people. This study employed a cross-sectional design and recruited 438 elderly people who were undergoing health examinations at the health management center in the Tri-Service General Hospital as study subjects. Basic demographic variables and impedance analysis values were used in four predictive models, namely, linear regression, random forest, support vector machine (SVM), and eXtreme Gradient Boosting (XGBoost) models, to predict DXA body composition. The data from 354 study subjects were used to develop the predictive model, while the data from 84 study subjects were used to validate the accuracy of the predictive model. The body composition of elderly people as estimated by InBody 720 was highly correlated with that estimated by DXA. The correlation coefficient between InBody 720 and DXA for muscle mass was 0.969, and that for fat mass was 0.935. Consistency analysis results showed that InBody 720 tends to underestimate muscle mass and fat mass. A comparison of the accuracy of the linear regression, random forest, SVM, and XGBoost models showed that the linear regression has the highest accuracy. The correlation coefficient between the new model and DXA for muscle mass and fat mass were 0.977 and 0.978, respectively. The new predictive model can be used to monitor the nutrition status of elderly people and identify people with sarcopenia in the community.

This study determined the most effective field method for quantifying fat-free mass (FFM) in elite youth male soccer players compared to dual X-ray absorptiometry (DXA) values and to develop prediction equations for FFM based on anthropometric variables. Forty-one male elite-standard youth soccer players, ages 16.2-18.0 years, undertook FFM assessments including bioelectrical impedance analysis, and different skinfold-based prediction equations. DXA provided a criterion measure of FFM. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses to develop soccer-specific prediction equations. Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998) equations showed the lowest biases, and no significant, standardized, and substantial differences against DXA. The new youth soccer-specific anthropometric equation explained 91% of the DXA-derived FFM variance using three circumferences, eight skinfolds, and one bone breadth. All field methods compared in this study may not be adequate for estimating FFM in elite youth male soccer players, except the equations of Slaughter et al (1988), Durnin and Wormersley (1974), and Sarria et al (1998). We recommend the use of the new soccer-specific equation proposed in this study as a valid alternative to DXA to quantify FFM among elite youth male players.

Dual-energy X-ray absorptiometry (DXA) was the first imaging tool widely utilized by clinicians to assess fracture risk, especially in postmenopausal women. The development of DXA nearly coincided with the availability of effective osteoporosis medications. Although osteoporosis in adults is diagnosed based on a T-score equal to or below − 2.5 SD, most individuals who sustain fragility fractures are above this arbitrary cutoff. This incongruity poses a challenge to clinicians to identify patients who may benefit from osteoporosis treatments. DXA scanners generate 2 dimensional images of complex 3 dimensional structures, and report bone density as the quotient of the bone mineral content divided by the bone area. An obvious pitfall of this method is that a larger bone will convey superior strength, but may in fact have the same bone density as a smaller bone. Other imaging modalities are available such as peripheral quantitative CT, but are largely research tools. Current osteoporosis medications increase bone density and reduce fracture risk but the mechanisms of these actions vary. Anti-resorptive medications (bisphosphonates and denosumab) primarily increase endocortical bone by bolstering mineralization of endosteal resorption pits and thereby increase cortical thickness and reduce cortical porosity. Anabolic medications (teriparatide and abaloparatide) increase the periosteal and endosteal perimeters without large changes in cortical thickness resulting in a larger more structurally sound bone. Because of the differences in the mechanisms of the various drugs, there are likely benefits of selecting a treatment based on a patient’s unique bone structure and pattern of bone loss. This review retreats to basic principles in order to advance clinical management of fragility fractures by examining how skeletal biomechanics, size, shape, and ultra-structural properties are the ultimate predictors of bone strength. Accurate measurement of these skeletal parameters through the development of better imaging scanners is critical to advancing fracture risk assessment and informing clinicians on the best treatment strategy. With this information, a “treat to target” approach could be employed to tailor current and future therapies to each patient’s unique skeletal characteristics.

As populations continue to age worldwide, the impact of sarcopenia on public health will continue to grow. The clinically relevant and increasingly common diagnosis of sarcopenia is at the confluence of three tectonic shifts in medicine: opportunistic imaging, precision medicine, and machine learning. This review focuses on the state-of-the-art imaging of sarcopenia and provides context for such imaging by discussing the epidemiology, pathophysiology, consequences, and future directions in the field of sarcopenia.

Dual X-ray absorptiometry (DXA) remains the most common mode of bone mineral density (BMD) evaluation. In adults, presence of a lumbar spine (LS) BMD T-score discrepancy (>1 SD difference between adjacent vertebrae) can indicate a vertebral fracture. In children, however, the clinical significance of such discrepancies is unknown. We conducted a retrospective study to evaluate the association between LS DXA and LS morphology to elucidate the clinical significance of an LS BMD Z-score discrepancy. We identified 360 DXA scans performed between September 2014 and May 2016 in patients 5–18 years of age. DXA scans were cross-referenced against available LS radiographs and vertebral fracture assessment (VFA) within the 6 months preceding or following a DXA scan. After excluding 44 DXA scans because of spinal hardware, incomplete DXA, or repeat scans, 316 DXA scans were included; 81 (25.6%) had either an LS radiograph or a VFA. Twenty-five of 81 patients (30.9%) had >1 SD difference between adjacent vertebrae in LS BMD Z-score. Two of these 25 patients (8%) had a lumbar vertebral fracture documented by a spine radiograph. Of the remaining 56 patients who did not have a discrepancy >1 SD, 6 patients (11%) had a lumbar vertebral fracture. Discrepancies in LS BMD Z-scores were not associated with lumbar vertebral fractures and, in the absence of fractures, likely represented vertebral developmental variants in children whose skeletons are still growing. Therefore, it does not appear justified to recommend further imaging based solely on the results of a DXA scan without clinically meaningful indications.

Background There is evidence that human immunodeficiency virus (HIV) infection and antiretroviral therapy (ART) are independent risk factors for osteoporosis and fracture which is not solely explained by changes in bone mineral density. Thus, we hypothesized that the assessment of trabecular microstructure might play an important role for bone quality in this population and might explain the increased fracture risk. In this study, we have assessed bone microstructure in the proximal femur using high-resolution magnetic resonance imaging (MRI) as well as in the extremities using high resolution peripheral quantitative computed tomography (HR-pQCT) in HIV-infected men and healthy controls and compared these findings to those based on areal bone mineral density (aBMD) derived from dual X-ray absorptiometry (DXA) which is the standard clinical parameter for the diagnosis of osteoporosis. Methods Eight HIV-infected men and 11 healthy age-matched controls were recruited and informed consent was obtained before each scan. High-resolution MRI of the proximal femur was performed using fully balanced steady state free precession (bSSFP) on a 3T system. Three volumes of interest at corresponding anatomic locations across all subjects were defined based on registrations of a common template. Four MR-based trabecular microstructural parameters were analyzed at each region: fuzzy bone volume fraction (f-BVF), trabecular number (Tb.N), thickness (Tb.Th), and spacing (Tb.Sp). In addition, the distal radius and distal tibia were imaged with HR-pQCT. Four HR-pQCT-based microstructural parameters were analyzed: trabecular bone volume fraction (BV/TV), Tb.N, Tb.Th, and Tb.Sp. Total hip and spine aBMD were determined from DXA. Results Microstructural bone parameters derived from MRI at the proximal femur and from HR-pQCT at the distal tibia showed significantly lower bone quality in HIV-infected patients compared to healthy controls. In contrast, DXA aBMD data showed no significant differences between HIV-infected patients and healthy controls. Conclusions Our results suggest that high-resolution imaging is a powerful tool to assess trabecular bone microstructure and can be used to assess bone health in HIV-infected men who show no differences to healthy males by DXA aBMD. Advances in MRI technology have made microstructural imaging at the proximal femur possible. Further studies in larger patient cohorts are clearly warranted.

Background: A number of questionnaire-based systems and the use of portable quantitative ultrasound scanners (QUS) have been devised in an attempt to produce a cost-effective method of screening for osteoporosis.Objective: to assess the sensitivity and specificity of different techniques and their ability to act as screening tools in relation to dual energy X-ray absorptiometry (DXA).Methods: 295 white postmenopausal women aged over 60 were enrolled. Each subject completed a standardized questionnaire which permits the measure of six osteoporosis indexes and had bone mineral density (BMD) measured using QUS and DXA. Sensitivity and specificity of the different techniques in relation to DXA were plotted as receiver-operating characteristic (ROC) curves at DXA T-score total hip ≤ -2.5 (osteoporosis).Results: BUA sensitivity and specificity values were respectively 76.8% and 51.2% at the total hip. The optimal cut-off T-score for QUS was -2 at the total hip. The osteoporosis self-assessment tool (OST) provided consistently the highest AUC (0.80) among the clinical tools and had the best sensitivity and specificity balance (90.2%-44.5%). OST negative likelihood ratio was 0.22.Conclusion: OST (based only on the weight and the age) performed slightly better than QUS and other risk questionnaires in predicting low BMD at the total hip

Background & aims: Aging is characterized by a loss of appendicular skeletal muscle mass (ASMM) leading to physical disability and death. Bioelectrical impedance analysis (BIA) is reliable in estimating ASMM but no prediction equations are available for elderly Caucasian subjects. The aim of the study was to develop and validate an equation derived from bioelectrical impedance analysis (BIA) to predict appendicular skeletal muscle mass (ASMM) in healthy Caucasian elderly subjects, taking dual X-ray absorptiometry (DXA) as the reference method, and comparing the reliability of the new equation with another BIA-based model developed by Kyle etal. (Kyle UG, Genton L, Hans D, Pichard C, 2003). Methods: With a cross-sectional design, 296 free-living, healthy Caucasian subjects (117 men, 179 women) over 60 years of age were enrolled. Lean mass of limbs was measured with DXA to ascertain ASMM (ASMMDxA). Whole-body tetrapolar BIA was performed to measure resistance (Rz), resistance normalized for stature (RI), and reactance (Xc). The BIA multiple regression equation for predicting ASMM was developed using a double cross-validation technique. The predicted ASMM values were compared with ASMMKyle, i.e. ASMM estimates derived from the model developed by Kyle etal. (Kyle etal., 2003). Results: Cross-validation resulted in a unique equation using the whole sample: ASMM (kg)=-3.964+(0.227*RI)+(0.095*weight)+(1.384*sex)+(0.064*Xc) [R2=0.92 and SEE=1.14kg]. In our sample, ASMMKyle differed significantly from the ASMMDxA (p

Summary Background Infant adiposity better predicts childhood obesity/metabolic risk than weight, but technical challenges fuel controversy over the accuracy of adiposity estimates. Objective We prospectively measured adiposity (%fat) in term newborns (NB) at 2 weeks (n = 41) and 1 year (n = 30). Methods %fat was measured by dual X-ray absorptiometry (DXA), PEAPOD and skin-folds (SF). DXAs were analyzed using Hologic Apex software 3.2(DXAv1) and a new version 5.5.2(DXAv2). Results NB %fat by DXAv2 was 55% higher than DXAv1 (14.2% vs. 9.1%), 45% higher than SF (9.8%), and 36% higher than PEAPOD (10.4%). Among NB, Pearson correlations were 0.73–0.89, but agreement (intra-class correlations) poor between DXAv2 and DXAv1 (0.527), SF (0.354) and PEAPOD (0.618). At 1 year, %fat by DXAv2 was 51% higher than DXAv1 (33.6% vs. 22.4%), and twice as high compared with SF (14.6%). Agreement was poor between DXAv2 and DXAv1 (0.204), and SF (0.038). The absolute increase in %fat from 2 weeks to 1 year was 19.7% (DXAv2), 13.6% (DXAv1) and only 4.8% by SF. Conclusion Analysis of the same DXA scans using new software yielded considerably higher adiposity estimates at birth and 1 year compared with the previous version. Using different modalities to assess body composition longitudinally is problematic. Standardization is gravely needed to determine how early life exposures affect childhood obesity/metabolic risk.

Background & aims: The main objectives of weight loss interventions in children and adolescents are to decrease fat mass while maintaining fat-free mass. Several methods are available to assess childhood and adolescence obesity, such as weight and height, bioelectrical impedance, skin-fold thickness measurements and other laboratory methods. The aim was to assess simple anthropometric indices as predictors of body-fat changes, using dual-energy X-ray absorptiometry measurements as reference method. Methods: Multi-intervention approach (diet, physical activity and psychological support in a family group- based treatment) was implemented with a one-year follow-up in 13- to-16-year-old overweight or obese Spanish adolescents. A total of 83 adolescents were recruited from Granada and Zaragoza, males (n=43) (31.6 kg/m2) and females (n=40) (32.0 kg/m2). We measured body composition with anthropometry and dual-energy X-ray absorptiometry. All measurements were made at baseline, and after 2 and 13 months. Random coefficient regression model was used to calculate the proportion of body composition changes during follow-up that would be explained by simple body composition indices based on anthropometric measures. Results: After controlling for age and Tanner stage, body mass index explained 76.5% of body composition changes in males and 90.1% in females, while fat mass index (assessed by skin-folds) explained 78.9% of body composition changes in males and 84.0% of body composition changes in females. Conclusions: In conclusion, we found that BMI was a good indicator of body fat composition changes in children and adolescents, although FMI assessed by anthropometry was also a good indicator., the Ministry of Health, Social Services and Equality; the Spanish Government (Carlos III Institute of Health. FIS. Grant PI051080, PI051579); European Regional Development Fund (MICINN-FEDER).

Objective The purpose of this cross-sectional study was to establish neighborhood built environment correlates of adiposity as measured by dual X-ray absorptiometry. The utility and methodological gains of using this measure for built environment research were further investigated by comparing model fit across parallel models on body mass index z-scores and waist circumference. Methods Pre-existing data collected from 2001 to 2011 on 576 overweight and obese Hispanic youth were compiled with built environment data, and 2000 census data for analyses conducted in 2012. Walking-distance buffers were built around participants' residential locations. Variables for park space, food access, walkability, and neighborhood socio-cultural aspects were entered into a multivariate regression model predicting percent body fat. Parallel models were built for body mass index z-score, and waist circumference. Results Significant associations were found between percent body fat and supermarket access for boys, and percent body fat and increased park space and decreased neighborhood linguistic isolation for girls. Neighborhood socio-cultural characteristics accounted for more variance in obesity compared to body mass index z-score or waist circumference. Conclusion Park access, food environment, and neighborhood socio-cultural characteristics are independent contributors to body fat in children, and the contribution of these risks differs by gender. There are incremental gains to using a more accurate measure of body fat in built environment obesity studies., Highlights • A study of obese/overweight Hispanic youth using dual X-ray absorptiometry • Percent body fat (%BF) was modeled on neighborhood environment characteristics. • Food access, walkability, parks, and socio-cultural aspects were related to %BF. • The final model for %BF was used to predict BMI z-score and waist circumference. • Using DXA to measure body fat has incremental gains in built environment research.

ObjectiveTo compare estimates by bioimpedance spectroscopy analysis (BIS) of extracellular water (ECW), fat mass (FM), and fat-free mass (FFM) against standard techniques of bromide dilution and dual energy X-ray absorptiometry (DXA) during intervention that causes significant changes in water compartments and body composition.MethodsBody composition analysis using BIS, bromide dilution, and DXA was performed in 71 healthy recreational athletes (43 men, 28 women; aged 18–40 years; BMI 24±0.4 kg/m2) who participated in a double-blinded, randomized, placebo-controlled study of GH and testosterone treatment. The comparison of BIS with bromide dilution and DXA was analyzed using linear regression and the Bland–Altman method.ResultsAt baseline, there was a significant correlation between BIS and bromide dilution-derived estimates for ECW, and DXA for FM and FFM (PPPConclusionIn healthy adults, bioimpedance spectroscopy is an acceptable tool for measuring ECW; however, BIS overestimates FFM and substantially underestimates FM compared with DXA.

Background Metatarsal fractures, especially of the fifth metatarsal, are common injuries of the foot in a young athletic population, but the risk factors for this injury are not well understood. Dual-energy x-ray absorptiometry (DXA) provides reliable measures of regional bone mineral density to predict fracture risk in the hip and lumbar spine. Recently, sub-regional metatarsal reliability was established in fresh cadaveric specimens and associated with ultimate fracture force. The purpose of this study was to assess the reliability of DXA bone mineral density measurements of sub-regions of the second and fifth metatarsals in a young, active population. Methods Thirty two recreationally active individuals participated in the study, and the bone density of the second (2MT) and fifth (5MT) metatarsals of each subject was measured using a Hologic QDR x-ray bone densitometer. Scans were analyzed separately by two raters, and regional bone mineral density, bone mineral content, and area measurements were calculated for the proximal, shaft, and distal regions of the bone. Intra-rater, inter-rater, and scan-rescan reliability were then determined for each region. Results Proximal and shaft bone mineral density measurements of the second and fifth metatarsal were reliable. ICC’s were variable across regions and metatarsals, with the distal region being the poorest. Conclusions Bone mineral density measurements of the metatarsals may be a better indicator of fracture risk of the metatarsals than whole body measurements. A reliable method for measuring the regional bone mineral densities of the metatarsals was found. However, inter-rater reliability and scan-rescan reliability for the distal regions were poor. Future research should examine the relationship between DXA bone mineral density measurements and fracture risk at the metatarsals.

Raymond, CJ, Dengel, DR, and Bosch, TA. Total and segmental body composition examination in collegiate football players using multifrequency bioelectrical impedance analysis and dual X-ray absorptiometry. J Strength Cond Res 32(3): 772-782, 2018-The current study examined the influence of player position on the agreement between multifrequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in National Collegiate Athletic Association Division I collegiate football athletes. Forty-four male collegiate athletes (age = 19 ± 1 year; height = 1.9 ± 1.0 m; and body mass = 106.4 ± 18.8 kg) participated. Player positions included: offensive linemen (OL; n = 7), tight ends (TE; n = 4), wide receivers (WR; n = 9), defensive linemen (DL; n = 6), defensive backs (DB; n = 8), linebackers (LB; n = 6), and running backs (RB; n = 4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA. Compared with DXA, MfBIA underestimated BF% (3.0 ± 3.8%), total FM (2.5 ± 4.3 kg), arm FM (0.4 ± 0.8 kg), arm FFM (1.4 ± 0.9 kg), leg FM (2.8 ± 2.0 kg), and leg FFM (5.4 ± 2.4 kg) (all p < 0.001; arm FM p = 0.002) and overestimated total FFM (-2.4 ± 4.5 kg) (p < 0.001). Limits of agreement (LOAs) were: ±7.39% (BF%), ±8.50 kg (total FM), ±1.50 kg (arm FM), ±1.83 kg (arm FFM), ±3.83 kg (leg FM), ±4.62 kg (leg FFM), and ±8.83 kg (total FFM). No significant differences were observed between devices for trunk FM (-0.3 ± 3.0 kg; p = 0.565) and trunk FFM (0.4 ± 2.4 kg; p = 0.278), with LOAs of ±5.92 and ±4.69 kg, respectively. Player position significantly affected all between-device mean body composition measurement differences (adjusted p ≤ 0.05), with OL demonstrating the greatest effect on each variable. Therefore, MfBIA does not seem accurate in examining between-player body composition in college football players.