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Background: There is limited research on body composition in persons with haemophilia (PwH). The literature describes an increased body fat distribution and decreased lean mass in PwH compared to healthy controls using bioimpedance analysis. Using dual x‐ray absorptiometry (DXA), which is known to be the most accurate method, this investigation aims to postulate reference data for body composition parameters within haemophilia severity phenotypes and age groups. Methods: Persons underwent whole body DXA screening using Horizon. Body fat percentage, estimated visceral adipose tissue (VAT), appendicular fat and lean mass, and lean and fat mass in relation to body height were assessed. Haemophilia severity and five age groups were distinguished. Results: Two hundred and one persons with mild (n = 44), moderate (n = 41), or severe (n = 116) haemophilia A/B (median age 40 [28–55; 1.IQ–3.IQ] years) were analysed. The median body fat percentage was 28.7% [25.5%–33.9%] and median estimated VAT was 657 g [403–954 g] with no significant difference between severity phenotypes (p =.474; p =.781). Persons with severe haemophilia had less lean mass compared to moderate and mild haemophilia (p =.013; p =.034). Total and appendicular fat is increased in older PwH (aged ≥40 years) compared to younger PwH (aged ≤29 years; p <.05). Lean mass did not differ between age groups. Conclusion: This study provides valuable reference data for body composition parameters in PwH. Persons with severe haemophilia show significantly less lean mass compared to persons with moderate or mild haemophilia. Body fat percentage and VAT did not differ between severity phenotypes, but increased with age. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB(18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA. [ABSTRACT FROM AUTHOR]

Summary: In this study of postmenopausal women in Malaysia, total adiposity was inversely associated with total BMD, while regional associations varied. No differences were detected across Malay, Chinese, and Indian ethnicities. Low BMD contributes substantially to morbidity and mortality, and increasing adiposity levels globally may be contributing to this. Purpose: To investigate associations of total and regional adiposity with bone mineral density (BMD) among a multi-ethnic cohort of postmenopausal women. Methods: Dual X-ray absorptiometry (DXA) imaging was undertaken for 1990 postmenopausal women without prior chronic diseases (30% Malay, 53% Chinese, and 17% Indian) from The Malaysian Cohort (TMC). The strength of the associations between standardized total and regional body fat percentages with total and regional BMD was examined using linear regression models adjusted for age, height, lean mass, ethnicity, education, and diabetes. Effect modification was assessed for ethnicity. Results: Women with a higher total body fat percentage were more likely to be Indian or Malay. Mean (SD) BMD for the whole-body total, lumbar spine, leg, and arm were 1.08 (0.11), 0.96 (0.15), 2.21 (0.22), and 1.36 (0.12) g/cm2, respectively. Total body and visceral fat percentage were inversely associated with total BMD (− 0.02 [95% CI − 0.03, − 0.01] and − 0.01 [− 0.02, − 0.006] g/cm2 per 1 SD, respectively). In contrast, subcutaneous and gynoid fat percentages were positively associated with BMD (0.007 [0.002, 0.01] and 0.01 [0.006, 0.02] g/cm2, respectively). Total body fat percentage showed a weak positive association with lumbar BMD (0.01 [0.004, 0.02]) and inverse associations with leg (− 0.04 [− 0.06, − 0.03]) and arm (− 0.02 [− 0.03, − 0.02]) BMD in the highest four quintiles. There was no effect modification by ethnicity (phetero > 0.05). Conclusion: Total adiposity was inversely associated with total BMD, although regional associations varied. There was no heterogeneity across ethnic groups suggesting adiposity may be a risk factor for low BMD across diverse populations. [ABSTRACT FROM AUTHOR]

Low bone mineral density (BMD) is common in adults with coeliac disease (CD), even in individuals adhering to a gluten-free diet (GFD). Women are more likely to have low BMD and have an increased risk of osteoporosis, so women with pre-existing low BMD related to CD are at an even higher risk. BMD assessed by dual X-ray absorptiometry (DXA) and bone quality assessed through quantitative ultrasound (QUS) were investigated in 31 premenopausal women with CD consuming a GFD, and 39 matched healthy controls from the Lower North Island, New Zealand. In addition, bone metabolism and nutrient status were assessed, and four-day diet diaries were used to estimate nutrient intake. No statistically significant differences were found in BMD assessed by DXA between the two groups at the hip, lumbar spine or forearm. However, the parameters measured by the QUS were significantly lower in CD participants. Dietary data indicated significantly lower intakes of energy, dietary fibre, magnesium and phosphorus in women with CD, likely as a result of a reduced intake of wholegrain foods, and suggested that both groups had inadequate intake of calcium. No significant differences were demonstrated in biochemical parameters. BMD and bone biomarkers indicated no differences between coeliac and healthy women in New Zealand. However, these findings suggest that QUS may be more sensitive for the coeliac population, due to the disease's affect on the trabecular bone, and warrant further research. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer is the most common cancer worldwide and a leading cause of cancer-related deaths in women. Mammographic breast density, the relative amount of fibroglandular tissue as seen on a mammogram, is one of the strongest predictors of breast cancer risk, with higher breast density associated with greater risk. Breasts undergo extensive fibroglandular tissue proliferation in early life, making this a potential window of vulnerability for carcinogen exposures. Early-life growth (e.g., height and weight) is also associated with breast cancer risk. Research into the 'developmental origins of health and disease' paradigms investigate the pathways of risk for disease in later life from early-life exposures across developmental phases. However, little is known about the association between early-life growth and breast density. Further investigation into these risk pathways could increase knowledge of disease etiology and help identify women at increased risk at an earlier age and inform potential mediation of breast cancer risk. Breast density is a strong intermediate endpoint to investigate the association between early-life exposures and breast cancer risk. This study investigates the association between early-life growth and breast density in young adult women measured using Optical Breast Spectroscopy (OBS) and Dual X-ray Absorptiometry (DXA). OBS measurements were obtained for 536 female Raine Cohort Study participants at ages 27–28, with 268 completing DXA measurements. Participants with three or more height and weight measurements from ages 8 to 22 were used to generate linear growth curves for height, weight and body mass index (BMI) using SITAR modelling. Three growth parameters (size, velocity and timing) were examined for association with breast density measures, adjusting for potential confounders. Women who reached their peak height rapidly (velocity) and later in adolescence (timing) had lower OBS-breast density. Overall, women who were taller (size) had higher OBS-breast density. For weight, women who grew quickly (velocity) and later in adolescence (timing) had higher absolute DXA-breast density. Overall, weight (size) was also inversely associated with absolute DXA-breast density, as was BMI. These findings provide new evidence that adolescent growth is associated with breast density measures in young adult women, suggesting potential mediation pathways for breast cancer risk in later life. [ABSTRACT FROM AUTHOR]

Preterm infants have increased body adiposity at term-equivalent age and risk of adverse metabolic outcomes. The aim of the study was to define how nutrient intake may impact body composition (BC) of very low-birth weight infants fed with early progressive enteral feeding and standard fortification. Eighty-six infants with <1500 g birth weight were included in the BC study and stratified into extremely preterm (EP) and very preterm (VP) groups. Nutrient intake was calculated during the first 28 days and BC assessed by dual X-ray absorptiometry at discharge and by skinfold thickness at 12 months of corrected age (CA). Total nutrient intake did not differ between the groups. EP infants had a higher fat mass percentage at discharge than VP infants (24.8% vs. 19.4%, p < 0.001); lean mass did not differ. None of the nutrients had any impact on BC of EP infants. Protein intake did not result in a higher lean mass in either group; fat intake was a significant predictor of increased fat mass percentage in VP infants at discharge (p = 0.007) and body adiposity at 12 months of CA (p = 0.021). Nutritional needs may depend on gestational age and routine fortification should be used with caution in more mature infants. [ABSTRACT FROM AUTHOR]

Nutritional compromise, low levels of vitamin D, chronic inflammation, abnormal growth, and physical inactivity affect bone metabolism and compromise long‐term bone health in individuals with epidermolysis bullosa (EB). The result is a high risk for osteopenia, osteoporosis, and pathologic fractures, but this important consequence of EB has been the focus of few investigations. Our scoping review found 21 publications that assessed the current understanding and clinical practices for monitoring of osteoporosis and its treatment in EB. Recommendations summarized from 13 of these publications include early nutritional and weight assessments before 2 years of age; bloodwork every 6–12 months starting at birth; Tanner stage assessments every 6 months to detect any pubertal delay; DEXA scans starting at age 6 years with repeated scans every 1–2 years, except in mild cases; and vitamin D supplementation of 80–320 IU daily for children 0–7 years and 720 IU for patients >8 years. [ABSTRACT FROM AUTHOR]

Background: To examine substrate oxidation in prepubertal and early pubertal children as a function of body weight, body composition, and sex during an exhaustive cycling test. Methods: This study included 320 children in prepubertal and early puberty (Tanner stage 1 or 2; n = 188 males) who completed a minimum of 4 stages (2–5 min/stage) of an adapted version of the McMaster exhaustive exercise protocol on an upright cycle ergometer. Substrate utilization, relative to individual VO2peak, was determined using VO2 and VCO2 data, obtained with breath-by-breath gas analysis during exercise. Results: Both peak (mg/kg lean body mass·min) and submaximal lipid oxidation (mg/kg lean body mass·min) were highest (P <.01) in children with healthy weight (HW), then overweight, and lowest in obese (OB). Both females with HW (compared with males with HW) and females with OB (compared with males with OB) had higher (P <.01) peak and submaximal lipid oxidation. In children with OB, fat-free mass correlated positively (P <.01) with submaximal lipid oxidation (r =.50). In contrast, in children with HW and overweight, fat-free mass correlated positively (P <.01) with carbohydrate oxidation (r =.52 and r =.47, respectively). Conclusion: Obesity during childhood may alter substrate oxidation during exercise. These results may have implications in the implementation of exercise programs in prepubertal or early puberty to control adiposity. [ABSTRACT FROM AUTHOR]

Relative Energy Deficiency in Sport (REDs) is a syndrome describing the relationship between prolonged and/or severe low energy availability and negative health and performance outcomes. The high energy expenditures incurred during training and competition put endurance athletes at risk of REDs. The objective of this study was to investigate differences in bone quality in winter endurance athletes classified as either low-risk versus at-risk for REDs. Forty-four participants were recruited (M = 18; F = 26). Bone quality was assessed at the distal radius and tibia using high resolution peripheral quantitative computed tomography (HR-pQCT), and at the hip and spine using dual X-ray absorptiometry (DXA). Finite element analysis was used to estimate bone strength. Participants were grouped using modified criteria from the REDs Clinical Assessment Tool Version 1. Fourteen participants (M = 3; F = 11), were classified as at-risk of REDs (≥ 3 risk factors). Measured with HR-pQCT, cortical bone area (radius) and bone strength (radius and tibia) were 6.8%, 13.1% and 10.3% lower (p = 0.025, p = 0.033, p = 0.027) respectively, in at-risk compared with low-risk participants. Using DXA, femoral neck areal bone density was 9.4% lower in at-risk compared with low-risk participants (p = 0.005). At-risk male participants had 21.9% lower femoral neck areal bone density (via DXA) than low-risk males (p = 0.020) with no significant differences in females. Overall, 33.3% of athletes were at-risk for REDs and had lower bone quality than those at low-risk. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to examine the muscle-to-bone ratio (MBR) in National Football League (NFL) players. Three hundred and forty-six NFL players had their total body lean, fat and bone masses determined using dual X-ray absorptiometry and were compared to 228 age-matched, healthy male controls. Compared to the control group, NFL players had a significantly lower percent total body fat (17.90±6.92 vs. 22.93±8.96%, p=0.053), but significantly greater total fat mass (19.76±11.29 vs. 17.84±12.11 kg, p<0.0001), lean mass (84.55±8.75 vs. 55.3±11.79 kg, p<0.0001), bone mineral content (4.58±0.45 vs. 2.91±0.67 kg, p<0.0001), and bone mineral density (1.61±0.11 vs. 1.26±0.21 g/cm2 , p<0.0001). NFL players had greater arm MBR (17.70±1.47 vs. 16.48±1.88, p<0.0001) than controls; however, both trunk (26.62±2.55 vs. 31.56±4.19, p<0.0001) and total (18.50±1.31 vs. 19.12±1.88, p<0.001) MBR were lower in NFL players. Leg MBR was not significantly different between NFL players and controls (16.72±1.53 vs. 16.85±1.87, p=0.34). When NFL players were categorized by their offensive or defensive position for comparison, no differences in total MBR were observed. However, leg MBR varied greatly among NFL players by position. It is possible that regional differences in MBR in the NFL players may be related to the demands of that position. [ABSTRACT FROM AUTHOR]

Trabecular microarchitecture contributes to bone strength, but its role in bone stress injury (BSI) risk in young healthy adults is unclear. Tibial volumetric BMD (vBMD), geometry, and microarchitecture, whole-body areal BMD, lean and fat mass, biochemical markers of bone metabolism, aerobic fitness, and muscle strength and power were measured in 201 British Army male infantry recruits (age 20.7 [4.3] years, BMI 24.0 ± 2.7 kg·m2) in week one of basic training. Tibial scans were performed at the ultra-distal site, 22.5 mm from the distal endplate of the non-dominant leg using High Resolution Peripheral Quantitative Computed Tomography (XtremeCT, Scanco Medical AG, Switzerland). Binary logistic regression analysis was performed to identify associations with lower body BSI confirmed by MRI. 20 recruits (10.0%) were diagnosed with a lower body BSI. Pre-injured participants had lower cortical area, stiffness and estimated failure load (p = 0.029, 0.012 and 0.011 respectively) but tibial vBMD, geometry, and microarchitecture were not associated with BSI incidence when controlling for age, total body mass, lean body mass, height, total 25(OH)D, 2.4-km run time, peak power output and maximum dynamic lift strength. Infantry Regiment (OR 9.3 [95%CI, 2.6, 33.4]) Parachute versus Line Infantry, (p ≤ 0.001) and 2.4-km best effort run time (1.06 [95%CI, 1.02, 1.10], p < 0.033) were significant predictors. Intrinsic risk factors, including ultradistal tibial density, geometry, and microarchitecture, were not associated with lower body BSI during arduous infantry training. The ninefold increased risk of BSI in the Parachute Regiment compared with Line Infantry suggests that injury propensity is primarily a function of training load and risk factors are population-specific. [ABSTRACT FROM AUTHOR]

Aim: Evaluate the impact of Tenofovir Disoproxil Fumarate (TDF) treatment on bone mineral density (BMD) for patients with chronic hepatitis B (CHB) with Dual X-ray absorptiometry (DEXA) and the Fracture Risk Assessment Tool (FRAX) score. Materials and Methods: A total of 38 CHB patients treated with TDF were included in this retrospective study. To estimate BMD, DEXA, demographic details, and laboratory values were examined in patients. The BMD measurements were compared after dividing the patients into 3 groups as normal BMD, osteopenic, and osteoporotic. FRAX scores (before and after DEXA) were calculated. Results: Twenty-one of the 38 (55.3%) cases of CHB infection were male, the median age was 51 (min-max: 29-71) years, and seven patients (18.4%) were over 60 years of age. The median TDF duration was median 6 (min-max: 3-13) years. Osteopenia, defined by DEXA results, was found in 17 patients (44.7%) at the lumbar spine site, 11 (28.9%) at the femoral neck, and 10 (26.3%) at the total hip. Osteoporosis was detected in six patients (15.8%) at the lumbar spine site. Pre-DEXA FRAX score and post-DEXA FRAX score were calculated. Only one patient (1/33, 3%) had a score over the intervention threshold, by post-DEXA FRAX score. None of the patients classified as low risk based on the pre-DEXA FRAX score had a post-DEXA FRAX score above the intervention threshold. When the TDF duration, serum phosphorus level, vitamin D levels, and ALP levels were compared, no significant differences were found between the groups. Conclusion: There are concerns about the negative effects of TDF used in CHB infection on BMD. However, BMD loss may not increase as the duration of TDF use increases. FRAX score is useful in identifying to risk of osteoporotic fracture. FRAX score can also eliminate the need for DEXA in most CHB cases. The FRAX score should be used in clinical practice to determine cases at risk. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to examine the muscle-to-bone ratio (MBR) in National Football League (NFL) players. Three hundred and forty-six NFL players had their total body lean, fat and bone masses determined using dual X-ray absorptiometry and were compared to 228 age-matched, healthy male controls. Compared to the control group, NFL players had a significantly lower percent total body fat (17.90±6.92 vs. 22.93±8.96%, p=0.053), but significantly greater total fat mass (19.76±11.29 vs. 17.84±12.11 kg, p<0.0001), lean mass (84.55±8.75 vs. 55.3±11.79 kg, p<0.0001), bone mineral content (4.58±0.45 vs. 2.91±0.67 kg, p<0.0001), and bone mineral density (1.61±0.11 vs. 1.26±0.21 g/cm2 , p<0.0001). NFL players had greater arm MBR (17.70±1.47 vs. 16.48±1.88, p<0.0001) than controls; however, both trunk (26.62±2.55 vs. 31.56±4.19, p<0.0001) and total (18.50±1.31 vs. 19.12±1.88, p<0.001) MBR were lower in NFL players. Leg MBR was not significantly different between NFL players and controls (16.72±1.53 vs. 16.85±1.87, p=0.34). When NFL players were categorized by their offensive or defensive position for comparison, no differences in total MBR were observed. However, leg MBR varied greatly among NFL players by position. It is possible that regional differences in MBR in the NFL players may be related to the demands of that position. [ABSTRACT FROM AUTHOR]

Background: Children spend increasing amounts of time on recreational screen media, which may lead to an obesogenic environment. Objectives: We investigated the association of trajectories of screen time across ages 3, 5 and 7 years with body composition at age 7 in the Odense Child Cohort. Methods: Data were collected in the Municipality of Odense, Denmark, between 2010 and 2019. Group‐based trajectory modelling was applied to group participants into four trajectories of prospective parent‐reported screen time. Body composition was assessed using dual‐energy x‐ray absorptiometry with calculated fat‐mass index (FMI) as the primary outcome. Primary models were linear multivariable regression models adjusted for participants' sex, age, birthweight, maternal origin, maternal education, maternal body‐mass‐index, and maternal age. Further models were adjusted for additional possible confounders. Selection bias was addressed by inverse probability weighting. Results: In total, 803 children (48.2% female) were included in the primary analysis. Participants with screen time at all time points were assigned to four trajectory groups [constant low screen time (12.7%), low increase (36.3%), high increase between ages 3 and 5 (33.5%) and high increase in screen time (17.5%)]. Sample characteristics differed across missing data status and trajectories. Mean FMI (kg/m2) and standard deviation (SD) were 3.7 (SD 1.3) and 3.9 (SD 1.6) for the constant low versus high screen time, respectively. No differences in FMI were found between screen time trajectory groups at age 7 (adjusted mean difference 0.1 kg/m2, 95% confidence interval −0.3, 0.5 for constant low versus high screen time). No consistent associations between screen time groups and secondary body composition outcomes were found. Conclusions: Results from this study do not suggest that recreational screen time from age 3 to 7 years is associated with adiposity or other measures of body composition. [ABSTRACT FROM AUTHOR]

Background: Robust evidence on whether diagnostic discordance exists between lumbar osteoporosis detected by quantitative computed tomography (QCT) vs. dual-energy X-ray absorptiometry (DXA) is still lacking. In this study involving a relatively large prospective cohort of older men (aged > 60 years) and postmenopausal women, we assessed lumbar QCT-derived volumetric bone mineral density (vBMD) and DXA-derived area BMD and evaluated their predictive performance for prevalent vertebral fracture (VF). Methods: A total of 501 patients who underwent spinal surgery from September 2020 to September 2022 were enrolled. The criteria recommended by the American College of Radiology and the World Health Organization were used for lumbar osteoporosis diagnosis. The osteoporosis detection rates between QCT and DXA were compared. QCT-vBMD was plotted against the DXA T score, and the line of best fit was calculated based on linear regression. Multivariate logistic regression was used to analyze the associations between risk factors and VF. Receiver operating characteristic curve analysis was performed, and the corresponding area under the curve (AUC) was calculated. Results: QCT screening showed that 60.7% of patients had osteoporosis, whereas DXA screening showed that 50.7% of patients had osteoporosis. Diagnoses were concordant for 325 (64.9%) patients. In all, 205 patients suffered a VF of at least one anatomic level. Of these, 84.4% (173/205) were diagnosed with osteoporosis by QCT, while only 73.2% (150/205) were diagnosed by DXA. Multivariate logistic regression showed that osteoporosis detected by QCT exhibited a stronger relationship with VF than that detected by DXA (unadjusted OR, 6.81 vs. 5.04; adjusted OR, 3.44 vs. 2.66). For discrimination between patients with and without VF, QCT-vBMD (AUC = 0.802) showed better performance than DXA T score (AUC = 0.76). Conclusion: In older patients undergoing spinal surgery, QCT-vBMD is more helpful than DXA in terms of osteoporosis detection rate and prediction of patients with prevalent VFs. [ABSTRACT FROM AUTHOR]

Purpose: Electrocardiogram (ECG) QRS voltages correlate poorly with left ventricular mass (LVM). Body composition explains some of the QRS voltage variability. The relation between QRS voltages, LVM and body composition in endurance athletes is unknown. Methods: Elite endurance athletes from the Pro@Heart trial were evaluated with 12-lead ECG for Cornell and Sokolow-Lyon voltage and product. Cardiac magnetic resonance imaging assessed LVM. Dual energy x-ray absorptiometry assessed fat mass (FM) and lean mass of the trunk and whole body (LBM). The determinants of QRS voltages and LVM were identified by multivariable linear regression. Models combining ECG, demographics, DEXA and exercise capacity to predict LVM were developed. Results: In 122 athletes (19 years, 71.3% male) LVM was a determinant of the Sokolow-Lyon voltage and product (β = 0.334 and 0.477, p < 0.001) but not of the Cornell criteria. FM of the trunk (β = − 0.186 and − 0.180, p < 0.05) negatively influenced the Cornell voltage and product but not the Sokolow-Lyon criteria. DEXA marginally improved the prediction of LVM by ECG (r = 0.773 vs 0.510, p < 0.001; RMSE = 18.9 ± 13.8 vs 25.5 ± 18.7 g, p > 0.05) with LBM as the strongest predictor (β = 0.664, p < 0.001). DEXA did not improve the prediction of LVM by ECG and demographics combined and LVM was best predicted by including VO2max (r = 0.845, RMSE = 15.9 ± 11.6 g). Conclusion: LVM correlates poorly with QRS voltages with adipose tissue as a minor determinant in elite endurance athletes. LBM is the strongest single predictor of LVM but only marginally improves LVM prediction beyond ECG variables. In endurance athletes, LVM is best predicted by combining ECG, demographics and VO2max. [ABSTRACT FROM AUTHOR]

Background: Many predictors of morbidity caused by metabolic disease are associated with body shape. 3D optical (3DO) scanning captures body shape and has been shown to accurately and precisely predict body composition variables associated with mortality risk. 3DO is safer, less expensive, and more accessible than criterion body composition assessment methods such as dual‐energy X‐ray absorptiometry (DXA). However, 3DO scanning has not been standardized across manufacturers for pose, mesh resolution, and post processing methods. Purpose: We introduce a scanner‐agnostic algorithm that automatically fits a topologically consistent human mesh to 3DO scanned point clouds and predicts clinically important body metrics using a standardized body shape model. Our models transform raw scans captured by any 3DO scanner into fixed topology meshes with anatomical consistency, standardizing the outputs of 3DO scans across manufacturers and allowing for the use of common prediction models across scanning devices. Methods: A fixed‐topology body mesh template was automatically registered to 848 training scans from three different 3DO systems. Participants were between 18 and 89 years old with body mass index ranging from 14 to 52 kg/m2. Scans were registered by first performing a coarse nearest neighbor alignment between the template and the input scan with an anatomically constrained principal component analysis (PCA) domain deformation using a device and gender specific bootstrap basis trained on 70 seed scans each. The template mesh was then optimized to fit the target with a smooth per‐vertex surface‐to‐surface deformation. A combined unified PCA model was created from the superset of all automatically fit training scans including all three devices. Body composition predictions to DXA measurements were learned from the training mesh PCA coefficients using linear regression. Using this final unified model, we tested the accuracy of our body composition models on a withheld sample of 562 scans by fitting a PCA parameterized template mesh to each raw scan and predicting the expected body composition metrics from the principal components using the learned regression model. Results: We achieved coefficients of determination (R2) above 0.8 on all nine fat and lean predictions except female visceral fat (0.77). R2 was as high as 0.94 (total fat and lean, trunk fat), and all root‐mean‐squared errors were below 3.0 kg. All predicted body composition variables were not significantly different from reference DXA measurements except for visceral fat and female trunk fat. Repeatability precision as measured by the coefficient of variation (%CV) was around 2–3x worse than DXA precision, with visceral fat %CV below 2x DXA %CV and female total fat mass at 5x. Conclusions: Our method provides an accurate, automated, and scanner agnostic framework for standardizing 3DO scans and a low cost, radiation‐free alternative to criterion radiology imaging for body composition analysis. We published a web‐app version of this work at https://shapeup.shepherdresearchlab.org/3do‐bodycomp‐analyzer/ that accepts mesh file uploads and returns templated meshes with body composition predictions for demo purposes. [ABSTRACT FROM AUTHOR]

Objective: Our study's purpose was to determine the most reliable Hounsfield unit (HU) measurement method to reflect bone mineral density (BMD) on cervical spine computed tomography (CT) and to identify any factors that influence these results.Materials and Methods: We retrospectively analyzed 439 consecutive patients with mild head and neck injuries. Mean HU values of the C2-C7 vertebra were determined on each sagittal, coronal, and axial CT image. Correlation patterns were analyzed between the HU value and corresponding dual-energy X-ray absorptiometry (DXA) in the lumbar vertebra (T-score) and femoral neck (T-score). A sub-group analysis was performed according to patient age, sex, and degree of spinal degeneration.Results: The correlation coefficients for HU and DXA ranged from 0.52 to 0.65 in all cervical segments. A simple linear regression analysis revealed the following formula: T-score = 0.01 × (HU) - 4.55. The mean HU values for osteopenia and osteoporosis were 284.0 ± 63.3 and 231.5 ± 52.8, respectively. The ROC curve indicated that the HU method has a sensitivity of 89.2% and specificity of 88.7% to diagnose osteoporosis. The HU measurement showed a high correlation value (range: r = 0.64-0.70) with spine DXA score regardless of the degree of degeneration or patient age or sex.Conclusion: HU values using the upper two cervical vertebrae (C2 and C3) reflected a more reliable BMD level than other segments. Additionally, the HU of cervical CT provided reliable information regardless of measurement plane, age or sex, and degree of degeneration. [ABSTRACT FROM AUTHOR]

Background: Cage subsidence may occur following transforaminal lumbar interbody fusion (TLIF) and lead to nonunion, foraminal height loss and other complications. Low bone quality may be a risk factor for cage subsidence. Assessing bone quality through Hounsfield units (HU) from computed tomography has been proposed in recent years. However, there is a lack of literature evaluating the correlation between HU and cage subsidence after TLIF. Methods: Two hundred and seventy-nine patients suffering from lumbar degenerative diseases from April, 2016 to August, 2018 were enrolled. All underwent one-level TLIF with a minimum of 1-year follow-up. Cage subsidence was defined as > 2 mm loss of disc height at the fusion level. The participants were divided into 2 groups: cage subsidence group (CS) and non-cage subsidence group (non-CS). Bone quality was determined by HU, bone mineral density of lumbar (BMD-l) and femoral (BMD-f) from dual-emission X-ray absorptiometry (DXA). HU of each vertebra from L1 to L4 (e.g., HU1 for HU of L1) and mean value of the four vertebrae (HUm) were calculated. Visual analog scale (VAS) of back/leg pain and Oswestry disability index (ODI) were used to report clinical outcomes. Results: Cage subsidence occurred in 82 (29.4%) cases at follow-ups. Mean age was 50.8 ± 9.0 years with a median follow-up of 18 months (range from 12 to 40 months). A total of 90.3% patients presented fusion with similar fusion rate between the two groups. ODI and VAS in leg were better in non-CS group at last follow-ups. Using receiver operating characteristic curves (ROCs) to predict cage subsidence, HUm provided a larger area under the curve (AUC) than BMD-l (Z = 3.83, P < 0.01) and BMD-f (Z = 2.01, P = 0.02). AUC for HU4 was larger than BMD-f and close to HUm (Z = 0.22, P = 0.481). Conclusions: Cage subsidence may indicate worse clinical outcomes. HU value could be a more effective predictor of lumbar cage subsidence compared with T-score of DXA after TLIF. [ABSTRACT FROM AUTHOR]

The accurate age at death assessment of unidentified adult skeletal individuals is a critical research task in forensic anthropology, being a key feature for the determination of biological profiles of individual skeletal remains. We have previously shown that the age-related decrease of bone mineral density (BMD) in the proximal femur could be used to assess age at death in women (Navega et al., J Forensic Sci 63:497–503, 2018). The present study aims to generate models for age estimation in both sexes through bone densitometry of the femur and radiogrammetry of the second metacarpal. The training sample comprised 224 adults (120 females, 104 males) from the "Coimbra Identified Skeletal Collection," and different models were generated through least squares regression and general regression neural networks (GRNN). The models were operationalized in a user-friendly online interface at https://osteomics.com/DXAGE2/. The mean absolute difference between the known and estimated age at death ranges from 9.39 to 13.18 years among women and from 10.33 to 15.76 among men with the least squares regression models. For the GRNN models, the mean absolute difference between documented and projected age ranges from 8.44 to 12.58 years in women and from 10.56 to 16.18 years in men. DXAGE 2.0 enables age estimation in incomplete and/or fragmentary skeletal remains, using alternative skeletal regions, with reliable results. [ABSTRACT FROM AUTHOR]

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 (p < 0.05), but it was decreased for the lower extremities (T3:13.06 ± 3.848 kg vs. T9:11.63 ± 3.49 kg, p < 0.05). Lean body mass was not significantly different after 9 years of ERT compared to before the ERT initiation (T0 to T9). Bone mineral density remained unchanged. Percent body fat increased (T0:39.1 ± 10.3%, vs. T9:43.1 ± 10.4%, p < 0.05). Six minute walking distance tended to increase after 3 years of ERT and decreased gradually thereafter, with no difference between T0-T9. Lean mass of the lower extremities adjusted for body weight was significantly correlated with 6 min walking distance (r = 0.712, p < 0.05). The current data show that enzyme replacement therapy may preserve lean body mass, bone mineral density and walking capacity in LOPD patients. [ABSTRACT FROM AUTHOR]

Czeck, MA, Roelofs, EJ, Evanoff, NG, and Dengel, DR. No Changes in body composition in NCAA Division I Collegiate Football Players due to COVID-19 restrictions. J Strength Cond Res 36(6): 1749–1752, 2022—The purpose of this study was to explore the impact of coronavirus disease 2019 (COVID-19) restrictions on body composition, assessed by dual x-ray absorptiometry (DXA), between the 2020 postseason (pre–COVID-19 restrictions) and the 2021 postseason (post–COVID-19 restrictions) in collegiate football players (n = 50). In addition, a subset of athletes (n = 23) was used to explore body composition variables across 4 postseason time points. Body composition variables assessed were total and regional body fat percent, total mass, lean mass, fat mass, bone mineral content, bone mineral density, and visceral adipose tissue mass. Paired t -tests were used to determine differences between the 2020 postseason and the 2021 postseason in body composition variables. Analysis of variance with Tukey HSD post hoc tests assessed significant differences in total and regional body composition across 4 years while adjusting for multiple comparisons. There were no significant differences (p > 0.05) between postseason 2020 and postseason 2021 for all measures of body composition. In a subset of athletes, body composition was analyzed over a 4-year period of time. There were no significant differences between all 4 time points for all measures of body composition. In conclusion, body composition variables in this study's subjects were not affected because of coronavirus disease 2019 restrictions or over 4 years of their collegiate football career. [ABSTRACT FROM AUTHOR]

Wichmann, TK, Wolfson, J, Roelofs, EJ, Bosch, TA, Bach, CW, Oliver, JM, Carbuhn, A, Stanforth, PR, and Dengel, DR. Longitudinal assessment of NCAA Division I football body composition by season and player age. J Strength Cond Res 36(6): 1682–1690, 2022—The purpose of this study was to examine longitudinal body composition changes by position, categorized by season and age, using dual X-ray absorptiometry in NCAA Division I football players. Seven hundred nineteen collegiate male football players aged 18–22 years ( X ¯ age ± SE = 19.4 ± 0.05 years) were examined. Percent body fat (%BF), fat mass (FM), lean mass (LM), total body mass (TM), bone mineral density (BMD), and visceral adipose tissue (VAT) were measured. Players were categorized into position groups of Linemen, Big Skill, Skill, or Special Team. One player scan was used per season (preseason, postseason, and spring season). Analysis of variance and Tukey HSD assessed total and regional differences across age, position groups, and seasons (significance of p < 0.05). Linemen had the greatest FM and LM measures compared with other groups for season and age. From preseason to postseason, %BF, FM, LM, and BMD significantly decreased for each position group. From postseason to spring season, %BF, FM, and VAT decreased, whereas LM increased within each position group. FM, VAT, LM, and TM increased with age in all position groups. The findings of this study indicate that body composition significantly worsened from preseason to postseason and improved from the preseason and postseason to the spring season. [ABSTRACT FROM AUTHOR]

Objectives Glucocorticoids (GCs) increase the risk of fracture through reduction in BMD; they may also reduce bone quality, but recent supporting data are scarce. We aimed to confirm these effects in a large population-based cohort. Methods We used data from patients referred for first hip and lumbar spine BMD estimation by the sole DXA scanner in the north-west of England between June 2004 and September 2016. We compared the history of fractures and BMD between patients currently on GCs and patients never exposed to GC. A logistic model adjusted for possible confounders. Results More than 20 000 subjects were included, 82% female, with mean age 63 (s. d. 13) years; 19% were currently on GCs. The patients on GCs were more often male, with higher BMI, but their age was similar to those not exposed to GC. Surprisingly, patients receiving GCs had ∼2% higher BMD at both sites (P  < 0.001) and lower prevalence of (history of) fractures (22% vs 34%; P  < 0.001). The corresponding odds ratio was 0.53 (95% CI: 0.49, 0.58); adjustment for age, sex, BMI and the number of indications for scanning did not alter the association. Conclusion In this large population-based cohort, current GC use compared with never use was associated with higher bone mass and fewer rather than more fractures after adjusting for confounders. These results might be subject to unmeasured confounding, but for now they do not lend support to a detrimental effect of GCs on bone. [ABSTRACT FROM AUTHOR]

BACKGROUND: In vertebrae, the amount of cortical bone has been estimated at 30–60%, but 45–75% of axial load on a vertebral body is borne by cortical bone. OBJECTIVE: To compare the role of L1 CT-attenuation and cortical thickness in predicting osteoporosis by opportunistic CT and explore cortical thickness value in osteoporosis. METHODS: We collected data of 94 patients who underwent DXA and thoracic and/or abdominal CT to demonstrate an entire L1 for other indications in routine practice. Patients were divided into three groups according to T-score: osteoporosis, osteopenia, or normal. CT-attenuation value and cortical thickness of L1 were measured. ANOVA analysis was utilized to analyze CT-attenuation and cortical thickness among the three groups. Sensitivity, specificity, and area under the curve (AUC) predicting low BMD were determined using ROC. Pearson correlations were employed to describe relationship between L1 BMD and CT-attenuation value, BMD, as well as cortical thickness. RESULTS: The mean cortical thickness was 0.83±0.11, 0.72±0.10, and 0.64±0.09 mm for normal, osteopenia, and osteoporotic subgroups, respectively. A statistically significant difference was observed in cortical thickness and CT-attenuation value among these three subgroups. A mean CT-attenuation value threshold of > 148.7 yielded 73.0% sensitivity and 86.0% specificity for distinguishing low BMD from normal with an AUC = 0.83. Pearson correlation analysis indicated that BMD was positively correlated with CT-attenuation (r = 0.666, P < 0.001) and cortical thickness (r = 0.604, P < 0.001). CONCLUSIONS: L1 CT-attenuation and cortical thickness measured on opportunistic CT can help predict osteoporosis. Compared with cortical thickness, CT-attenuation is a more sensitive and accurate index for distinguishing low BMD from normal. [ABSTRACT FROM AUTHOR]

Czeck, MA, Roelofs, EJ, Dietz, C, Bosch, TA, and Dengel, DR. Body composition and on-ice skate times for NCAA Division I collegiate male and female ice hockey athletes. J Strength Cond Res 36(1): 187–192, 2022—This study's purpose was to explore positional differences for an on-ice timed skate test and its relationship to body composition. Male (n = 15) and female (n = 18) collegiate hockey players participated in this study (total n = 33). Each player was categorized by position of forward or defensemen. Dual x-ray absorptiometry assessed total body composition variables of lean, fat, and bone mass as well as regional measures of lean mass, fat mass, and visceral adipose tissue. Total time and section times were determined for the on-ice skating test through a gated automatic timing system at 9, 18, 24, 42, 48, 66, 82, 132, and 148 m. Analysis of variance and Tukey's honest significance difference assessed on-ice skate time differences between positions (p ≤ 0.05). Correlations between body composition variables and skate times were determined for change of direction, skating time, linear skate time, and total skate time. There were no significant differences between positions for skate times (p > 0.05). Body fat percent (p = 0.007; r = 0.55), total fat mass (p = 0.027; r = 0.46), and leg fat mass (p = 0.019; 0.49) were significantly correlated with total skate time in men, whereas only body fat percent was significantly correlated with change of direction (p = 0.022; r = 0.54) and total skate times (p = 0.016; r = 0.56) in women. The total upper-body mass to leg lean mass ratio was significantly correlated with change of direction (p = 0.036; r = 0.50) in women. In conclusion, the results from this study suggest no differences between on-ice skating times between forwards and defensemen. However, body fat percentage was correlated with on-ice skate times in male and female collegiate hockey players. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose of Review: The purpose of this review is to inform researchers and clinicians with the most recent imaging techniques that are employed (1) to opportunistically screen for osteoporosis and (2) to provide a better understanding into the disease etiology of osteoporosis. Recent Findings: Phantomless calibration techniques for computed tomography (CT) may pave the way for better opportunistic osteoporosis screening and the retroactive analysis of imaging data. Additionally, hardware advances are enabling new applications of dual-energy CT and cone-beam CT to the study of bone. Advances in MRI sequences are also improving imaging evaluation of bone properties. Finally, the application of image registration techniques is enabling new uses of imaging to investigate soft tissue-bone interactions as well as bone turnover. Summary: While DXA remains the most prominent imaging tool for osteoporosis diagnosis, new imaging techniques are becoming more widely available and providing additional information to inform clinical decision-making. [ABSTRACT FROM AUTHOR]

The comprehension of trabecular bone damage processes could be a crucial hint for understanding how bone damage starts and propagates. Currently, different approaches to bone damage identification could be followed. Clinical approaches start from dual X-ray absorptiometry (DXA) technique that can evaluate bone mineral density (BMD), an indirect indicator of fracture risk. DXA is, in fact, a two-dimensional technology, and BMD alone is not able to predict the effective risk of fractures. First attempts in overcoming this issue have been performed with finite element (FE) methods, combined with the use of three-dimensional high-resolution micro-computed tomographic images. The purpose of this work is to evaluate damage initiation and propagation in trabecular vertebral porcine samples using 2D linear-elastic FE models from DXA images and 3D linear FE models from micro-CT images. Results show that computed values of strains with 2D and 3D approaches (e.g., the minimum principal strain) are of the same order of magnitude. 2D DXA-based models still remain a powerful tool for a preliminary screening of trabecular regions that are prone to fracture, while from 3D micro-CT-based models, it is possible to reach details that permit the localization of the most strained trabecula. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 < 0.001) and wrist circumferences (p < 0.001), elbow width (p = 0.049), BMD (p < 0.001), BMC (p < 0.001), LM (p = 0.001), humerus (p = 0.003) and radio-ulnar bone length (p < 0.001) were all greater in the dominant upper extremity. BMC (p < 0.001) and LM (p < 0.001) were greater in the contralateral lower extremity, whereas FM (p = 0.028) was greater in the ipsilateral lower extremity. This is the first study to report significant side-to-side differences in both upper and lower extremities in high-level female tennis players. [ABSTRACT FROM AUTHOR]

Three years of high‐dose vitamin D supplementation (400 IU, 4000 IU, 10,000 IU) in healthy vitamin D–sufficient individuals aged 55 to 70 years (serum 25(OH)D 30–125 nmol/L at baseline), resulted in a negative dose‐response relationship for bone density and strength. This study examined whether response differed between males and females. A total of 311 participants (53% male) were randomized to 400 IU (male = 61, female = 48), 4000 IU (male = 51, female = 49), or 10,000 IU (male = 53, female = 49) daily vitamin D3. Participants were scanned with high‐resolution peripheral quantitative computed tomography (HR‐pQCT) to measure total volumetric BMD (TtBMD) at baseline, 6, 12, 24, and 36 months. Finite element analysis estimated bone strength. Balance, physical function, and clinical biochemistry parameters were also assessed. Constrained linear mixed effects models determined time‐by‐treatment group‐by‐sex interactions. Baseline, 3‐month, and 3‐year levels of 25(OH)D were 76.3, 76.7, and 77.4 nmol/L (400 IU); 81.3, 115.3, and 132.2 (4000 IU); and 78.4, 188.0, and 144.4 (10,000 IU), respectively. There were significant time‐by‐treatment group‐by‐sex interactions for TtBMD at the radius (p =.002) and tibia (p =.005). Treatment with 4000 IU or 10,000 IU compared to 400 IU resulted in TtBMD losses in females, but this was not observed with males. After 3 years, females lost 1.8% (400 IU), 3.8% (4000 IU), and 5.5% (10,000 IU), whereas males lost 0.9% (400 IU), 1.3% (4000 IU), and 1.9% (10,000 IU) at the radius. At the tibia, losses in TtBMD were smaller, but followed a similar trend. There were no significant bone strength interactions. Vitamin D supplementation with 4000 IU or 10,000 IU, compared with 400 IU daily, resulted in greater losses of TtBMD over 3 years in healthy vitamin D–sufficient females, but not males. These results are clinically relevant, because vitamin D supplementation is widely administered to postmenopausal females for osteoporosis prevention. Our findings do not support a benefit of high‐dose vitamin D supplementation for bone health, and raise the possibility of harm for females. © 2020 American Society for Bone and Mineral Research (ASBMR). [ABSTRACT FROM AUTHOR]

The primary study objective was to measure positional differences in total and regional body composition among female NCAA Division I collegiate volleyball players using dual X-ray absorptiometry (DXA). The secondary objective was to examine normative age curves for fat and lean mass (LM) variables. Ninety female volleyball players from 5 universities received a DXA scan. Athletes were categorized by position: middle blocker (MB = 31), outside hitter (OH = 32), setter (ST = 9), and Libero (LB = 18). Height, body mass, total and regional fat mass (FM), LM, bone mineral density (BMD), and abdominal visceral adipose tissue were measured by DXA. Body mass distribution ratios were calculated. The secondary age analysis included a subset of 153 DXA scans (n = 83, ages 18-21 years). Front row players (i.e., MB and OH) had significantly greater total and regional LM and BMD measures (p < 0.05, all), compared with non-front row players (i.e., LB and ST). Differences in total LM (p,0.001) were significantly influenced by height. Front row players had consistently lower mass distribution ratios compared with non-front row players (p,0.05, all). Lean mass index (LMI, p50.752) and FM index (FMI, p = 0.392) were not significantly different across ages. Back row players have greater relative upper body mass, whereas mass in front row players is more evenly distributed between the upper and lower body. Bone mineral density differences may be influenced by repeated impact of jumping during the attacking and blocking actions of front row players. Minimal changes in LMI and fluctuations in FMI can be expected across an athlete's career. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine body composition of National Collegiate Athletic Association Division I female soccer players by position and season. One hundred seventy-five female athletes were categorized by positions of forward (n=47), midfielder (n=51), defender (n=57), and goalkeeper (n=20). A dual X-ray absorptiometry scan assessed percent body fat, total lean mass, total fat mass, arm and leg lean mass and fat mass, and visceral adipose tissue. Goalkeepers had significantly higher total, arm, and leg lean mass and fat mass compared to all other positions (p<0.05). For seasonal changes, body fat percentage was significantly higher in winter off-season (26.7%) compared to summer off-season (25.7%) and pre-season (25.8%; p<0.01) for all positions. Total and leg lean mass was significantly lower in winter off-season compared to all other seasons, and total lean mass was significantly higher in summer off-season than pre-season (p<0.01). Overall, goalkeepers were significantly different than all other positions. Body fat percentage increased and lean mass decreased in winter off-season indicating potential undesired changes in training and/or nutrition over the break whereas lean mass was the highest in summer off-season potentially reflecting the emphasis on resistance training and increased volume of training. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: Uncemented stems in primary total hip replacement (THR) are concerning in the elderly due to ectatic femoral canals and cortical thinning resulting in higher incidence of fracture and subsidence in this population. To obviate this concern, the authors developed a technique using autologous impaction bone grafting to achieve a better fitting femoral stem. The aim of this randomised clinical trial was to assess the efficacy of the technique.Methods: From 2013 to 2015, a total of 98 consecutive participants (100 primary THR procedures) were inducted into a single-institution, single-blinded, randomised clinical trial assessing, with radiostereometric analysis (RSA), the efficacy of autologous impaction bone grafting in uncemented primary THR compared with traditional uncemented primary THR technique. The primary outcome measure was femoral component migration using RSA. Secondary outcomes were post-operative proximal femoral bone density (using DEXA), hip function and quality of life using Oxford Hip Score (OHS) and Short Form-12 Health Survey (SF-12), hip pain and patient satisfaction.Results: There was no difference in femoral component stability (p > 0.5) or calcar resorption between the Graft and No Graft Groups at two years. There was also no difference in OHS, SF-12, pain or satisfaction between the Graft and No Graft Groups at two years (p > 0.39).Conclusions: Autologous impaction bone grafting in uncemented primary THR has shown its short-term post-operative outcomes to be equivalent to standard uncemented technique, whilst offering a better fit in patients who are between femoral stem sizes.Australian Clinical Trial Registration Number: ACTRN12618000652279. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

To examine measures of total and regional body composition using dual X-ray absorptiometry (DXA) in NCAA Division I collegiate equestrian athletes, 31 female collegiate equestrian athletes were matched to a population of normal controls by age and body mass index. Total and regional fat tissue mass (FM), lean tissue mass (LM), bone mineral density (BMD), and abdominal visceral adipose tissue (VAT) were measured by DXA. Equestrian athletes had a significantly (p=0.03) lower total body fat percentage (%fat) than controls. There were no significant differences in total LM and VAT between equestrian athletes and controls. However, equestrian athletes, when compared to the controls, had significantly lower leg %fat, leg FM and higher leg LM. The greater leg LM in equestrian riders resulted in a smaller upper to lower body LM ratio compared to controls. There was no difference in leg BMD between equestrian athletes and controls. There were no significant differences between the 2 styles of riding (i. e., hunt seat and western style) in regards to body composition. The lower total %fat in equestrian athletes seems to be influenced by differences in leg composition, with equestrian athletes having significantly more LM and less FM. [ABSTRACT FROM AUTHOR]

Body composition and bone mineral density of Division 1 collegiate football players: a consortium of college athlete research study. J Strength Cond Res 33(5): 1 3 3 9 - 1346, 2 0 1 9 -T h e purpose of this study was to generate normative data for total and regional body composition in Division 1 collegiate football players using dual-energy x-ray absorptiometry (DXA) and examine positional differences in total and regional measurements. Data were used from the Consortium of College Athlete Research (C-CAR) group. Four hundred sixty-seven players were included in this study. Height, body mass, total and regional fat mass, lean mass, and bone mineral density were measured in each athlete in the preseason (June- August). Players were categorized by their offensive or defensive position for comparisons. Linemen tended to have the higher fat and lean mass measures (p < 0.05 for all) compared with other positions. Positions that mirror each other (e.g. linemen) had similar body composition and body ratios. All positions were classified as overweight or obese based on body mass index (BMI) (> 2 5 k g - r r r 2), yet other than offensive and defensive linemen, all positions had healthy percent body fat (1 3 -2 0% ) and low visceral fat mass (< 5 0 0 g). The data presented here provide normative positional data for total and regional fat mass, lean mass, and bone density in Division 1 collegiate football players. Player position had a significant effect on body composition measures and is likely associated with on-field positional requirements. From a player's health perspective, although all positions had relatively high BMI values, most positions had relatively low body fat and visceral fat, which is important for the health of players during and after their playing career. The increased accuracy and reliability of DXA provides greater information, regarding positional differences in college football players compared with other methods. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Tetrasomy 18p is a rare chromosomal abnormality, resulting from an additional iso‐chromosome composed of two copies of the short arm. It is characterized by craniofacial abnormalities, neuromuscular dysfunction, and developmental delay. The Chromosome 18 Clinical Research Center has established the largest cohort of individuals with this rare genetic condition. Here, we describe a case series of 21 individuals with tetrasomy 18p who have a previously unreported clinical finding: low bone mineral density. Most individuals met criteria for low bone density despite being relatively young (mean age of 21 years). Clinicians providing care to individuals affected by Tetrasomy 18p should be aware of their increased risk for decreased bone density and pathological fractures. [ABSTRACT FROM AUTHOR]

This study has been undertaken in order to describe the bone mass distribution of the dry human radius via dual x-ray absorptiometry (DXA) with a Norland XR-800 densitometer machine. A sample of 39 dry radius bones was used. Two projections were made: antero-posterior and lateral, and five regions of interest were selected. The bone densities and the bone mineral contents of the various regions of the radius in the two projections were compared using Student's t tests for paired samples, with statistically significant differences being found in all of the values, except in the proximal extremity (P Ext). The area of greatest bone mineral content (BMC) was the medial diaphysis (M Diaph), followed by the distal extremity (D Ext), with the lowest value being found in the proximal extremity (P Ext). As for bone mineral density (BMD), a great symmetry is observed if we take the mean point of the longitudinal axis as a reference, with it being distributed from highest to lowest from the central part to the extremities. A correlation study of the BMD and BMC values between the segments themselves and with the total, in both positions, provides us with a high correlation (p ≤ 0.01), with the highest correlation value being found for the proximal diaphysis (P Diaph) region, indicating the heterogeneous nature of the distribution of the radius bone mass. Bone densitometry via DXA is useful in order to establish an overview of the structural construction of the human radius. [ABSTRACT FROM AUTHOR]

Meaningful change in bone mineral density (BMD) should be equal or higher than institutional least significant change (LSC). But some facilities use vendor's LSC which is discouraged by International Society for Clinical Densitometry (ISCD). The aim of this study was to find the impact of scan interpretation upon interval BMD changes using vendors and institutional LSCs. This prospective study was conducted at Joint Commission International-accredited facility of Pakistan from April–June 2017 using Hologic Discovery-A scanner. As per ISCD recommendations, precision error and LSC of two technologists were measured. Serial BMD changes such as deterioration or improvement interpreted based on vendor's and institutional LSCs were compared. Serial BMD changes in 102 patients were included, having a mean age, male:female ratio, and mean body mass index of 63 years, 94%:06%, and 29.274 kg/m2, respectively. Mean menopausal age was 47 years and mean duration between two dual X-ray absorptiometry (DXA) studies was 3 years. BMD changes over hip were found significant in 55% and 53% cases against vendor's and institutional LSCs, respectively (nonsignificant discordance in 2%). BMD changes using vendor's and institutional LSCs were found significant over L1-4 (62% vs. 46%; discordance: 14%) and distal forearm (77% vs. 35%; discordance: 41%), respectively. Interpretations based on vendor's LSCs revealed significantly overestimated deterioration over forearm and improvement over L1-4 BMD values. We conclude that vendor's provided LSC for interpretation of serial DXA is misleading and has a significant negative impact upon patients' management. Every DXA facility must use its own LSC as per ISCD guidelines. Furthermore, ISCD must consider publishing cutoff values for LSC for distal forearm measurement. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: (i) To predict the future risk of osteoporotic fracture in women using a simple forearm radiograph. (ii) To assess osteoporosis in southern Indian women by using radiogrammetric technique in comparison with dual‐energy X‐ray absorptiometry (DXA) and X‐ray phantom study. Methods: The bone mineral density (BMD) of the right proximal femur by DXA and the X‐ray measurements were acquired from the right forearm. The combined cortical thickness at the second to fourth metacarpal region (M‐CCT), radius (R‐CCT) and ulna (U‐CCT) were derived in all the studied population. The aluminium phantom study was conducted by varying the X‐ray source to film distance at 100 cm and 150 cm, respectively. The feed forward back propagation neural network was used for classification of low bone mass group and normal. Results: The combined cortical thickness of M‐CCT, R‐CCT and U‐CCT of the total studied population was strongly correlated with DXA femur Th.BMD measurements (r = 0.77, r = 0.61 and r = 0.59 [P < 0.01]). The predicted future osteoporotic fracture risk for the low bone mass group, post‐menopausal women and old‐aged women population was found to be 92%, 62.8%, and 64.7%, respectively. The accuracy of neural network classifier for training set, testing set was found to be 97.5% and 87.5% in the studied population. Conclusion: The results suggested that M‐CCT and M‐CCT (%) at the second metacarpal region are useful in predicting the future risk of osteoporotic fracture in women. The aluminium phantom study with an X‐ray tube to film distance of 100 cm mimics an exact condition of forearm radiogrammetry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study determined the most effective field method for quantifying body fat percentage in male elite youth soccer players and developed prediction equations based on anthropometric variables. Forty-four male elite-standard youth soccer players aged 16.3-18.0 years underwent body fat percentage assessments, including bioelectrical impedance analysis and the calculation of various skinfold-based prediction equations. Dual X-ray absorptiometry provided a criterion measure of body fat percentage. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses were used to develop soccer-specific prediction equations. The equations from Sarria et al. (1998) and Durnin & Rahaman (1967) reached very large correlations and the lowest biases, and they reached neither the practically worthwhile difference nor the substantial difference between methods. The new youth soccer-specific skinfold equation included a combination of triceps and supraspinale skinfolds. None of the practical methods compared in this study are adequate for estimating body fat percentage in male elite youth soccer players, except for the equations from Sarria et al. (1998) and Durnin & Rahaman (1967). The new youth soccer-specific equation calculated in this investigation is the only field method specifically developed and validated in elite male players, and it shows potentially good predictive power. [ABSTRACT FROM AUTHOR]

Aim: The aim was to compare and contrast the lumbal area DEXA measurements made in lateral and front-back positions in the clinically diagnosed female patients with osteoporosis. Material and methods: From the female patients that were referred to our clinic due to low energy fractures that occurred in areas other than the vertabrae, whom were thought to have osteoporotic fractures, were postmenaposal with no known history of diseases, and medication that can lead to osteoporosis and fracture, with no known previous diagnosis of osteoporosis, 39 patients have been included in the study. Anteroposterior and lateral standart lumbar DEXA measurements were performed on all patients Results: The results of our study revealed that the the laterally performed lumbar Dual Energy X-ray Absorbsiometer (DEXA) measurements have diagnostic advantage in osteoporosis over anteroposteriorly performed measurements . The antiosteoporotic treatment would have beeen prescribed to 82% of the patients if the anteroposteriorly performed lumbar region Dual Energy X-ray Absorbsiometer (DEXA) measurements were taken into account, while when laterally performed measurements were taken into account the percentage was 97.5%. Conclusion: If lateral lumbar area Dual Energy X-ray Absorbsiometer (DEXA) measurements are used in diagnosing osteoporosis more patients would receive the required treatment and the risk of the osteoporotic low energy fractures could be lowered. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Experimental autoimmune myasthenia gravis (EAMG), an animal model of myasthenia gravis (MG), can be induced in C57BL/6 (B6, H-2 b) mice by 2−3 injections withTorpedo californicaAChR (tAChR) in complete Freund’s adjuvant. Some EAMG mice exhibit weight loss with muscle weakness. The loss in body weight, which is closely associated with bone structure, is particularly evident in EAMG mice with severe muscle weakness. However, the relationship between muscle weakness and bone loss in EAMG has not been studied before. Recent investigations on bone have shed light on association of bone health and immunological states. It is possible that muscle weakness in EAMG developed by anti-tAChR immune responses might accompany bone loss. We determined whether reduced muscle strength associates with decreased bone mineral density (BMD) in EAMG mice. EAMG was induced by two injections at 4-week interval oftAChR and adjuvants in two different age groups. The firsttAChR injection was either at age 8 weeks or at 15 weeks. We measured BMD at three skeletal sites, including femur, tibia, and lumbar vertebrae, using dual energy X-ray absorptiometry. Among these bone areas, femur of EAMG mice in both age groups showed a significant decrease in BMD compared to control adjuvant-injected and to non-immunized mice. Reduction in BMD in induced EAMG at a later-age appears to parallel the severity of the disease. The results indicate that anti-tAChR autoimmune response alone can reduce bone density in EAMG mice. BMD reduction was also observed in adjuvant-injected mice in comparison to normal un-injected mice, suggesting that BMD decrease can occur even when muscle activity is normal. Decreased BMD observed in bothtAChR-injected and adjuvant-injected mice groups were discussed in relation to innate immunity and bone-related immunology involving activated T cells and tumour necrosis factor-related cytokines that trigger osteoclastogenesis and bone loss. [ABSTRACT FROM PUBLISHER]