Whole-body Dual-energy X-ray Absorptiometry Scans Research Articles

Whole-body and forearm muscle protein metabolism in patients with acromegaly before and after treatment.

Active acromegaly is characterized by increased lean body mass but the mechanisms underlying the protein anabolic effect are unclear. To study if active acromegaly induces reversible changes in whole-body and skeletal muscle protein kinetics. Eighteen patients with acromegaly were investigated before and 47 ± 10 weeks after disease control by surgery (n = 8) and/or medical treatment (n = 10). Labelled phenylalanine and tyrosine tracers were employed to assess whole-body and regional forearm muscle protein kinetics. Intramyocellular protein signaling was assessed in skeletal muscle biopsies, and whole-body DXA scan and indirect calorimetry assessed lean body mass (LBM) and resting energy expenditure, respectively. Disease control induced a 7% decrease in lean body mass (p < 0.000) and a 14% decrease in LBM-adjusted energy expenditure. Whole-body phenylalanine breakdown decreased after disease control (p = 0.005) accompanied by a decrease in the degradation of phenylalanine to tyrosine (p= 0.005) and a decrease in whole-body phenylalanine synthesis (p = 0.030). Skeletal muscle protein synthesis tended to decrease after disease control (p = 0.122), whereas the muscle protein breakdown (p = 0.437) and muscle protein loss were unaltered (p = 0.371). ULK1 phosphorylation, an activator of protein breakdown, increased after disease control (p= 0.042). Active acromegaly represents a reversible high flux state in which both whole-body protein breakdown and synthesis are increased, whereas forearm muscle protein kinetics are unaltered. Future studies are needed to decipher the link between protein kinetics and the structure and function of the associated GH-induced increase in lean body mass.

The influence of body composition and fat distribution on circadian blood pressure rhythm and nocturnal mean arterial pressure dipping in patients with obesity.

Loss of physiological nocturnal blood pressure (BP) decline is an independent predictor of cardiovascular risk and mortality. The aim of the study was to investigate the influence of body composition and fat distribution on 24-hour BP pattern and nocturnal dipping of mean arterial pressure (MAP) in patients with obesity. The study comprised 436 patients, 18 to 65 years old (306 women), with BMI ≥30 kg/m2. Body composition was assessed with dual-energy X-ray absorptiometry (DXA) and blood pressure was assessed by 24-hour BP monitoring. The prevalence of hypertension was 64.5% in patients with BMI <40 kg/m2 and increased to 78.7% in individuals with BMI ≥50 kg/m2 (p = 0.034). The whole-body DXA scans showed that the hypertensive patients were characterized by a greater lean body mass (LBM) and a higher abdominal-fat-to-total-fat-mass ratio (AbdF/FM), while the normotensive participants had greater fat mass, higher body fat percentage and more peripheral fat. Loss of physiological nocturnal MAP decline was diagnosed in 50.2% of the patients. The percentage of non-dippers increased significantly: from 38.2% in patients with BMI <40 kg/m2 to 50.3% in those with BMI 40.0-44.9 kg/m2, 59.0% in patients with BMI 45.0-49.9 kg/m2, 71.4% in those with BMI 50.0-54.9 kg/m2 and 83.3% in patients with BMI ≥55 kg/m2 (p = 0.032, p = 0.003, p<0.001, and p = 0.002 vs. BMI <40 kg/m2, respectively). The multivariable regression analysis showed that patients at the highest quartiles of body weight, BMI, LBM and AbdF/FM had significantly reduced nocturnal MAP dipping compared with patients at the lowest quartiles, respectively.

Accuracy of body mass index compared to whole-body dual energy X-ray absorptiometry in diagnosing obesity in adults in the Eastern Province of Saudi Arabia: A cross-sectional study.

Obesity is a major health concern that requires accurate diagnosis and management. Body mass index (BMI) commonly used to diagnose obesity, has limitations in accurately assessing body fat. Body fat percentage (BF%) from whole-body dual energy X-ray absorptiometry (DEXA) scans is gaining popularity as a more accurate method in diagnosing obesity. This cross-sectional study included 319 adult patients who underwent whole-body DEXA scans in the Eastern Province of Saudi Arabia from May 2016 to December 2021 were recruited from three medical centers, where data for whole-body DEXA were available. Body fat percent was obtained from the whole-body DEXA scan reports and were compared to BMI to evaluate prevalence of obesity. Data was extracted by reviewing patients' records using a structured data collection tool. BMI was defined using WHO criteria, and diagnostic performance was assessed by estimating specificity, sensitivity, likelihood ratios, and predictive values, and by constructing receiver operating characteristic (ROC) curves for BMI to detect obesity by age group. The gender-specific BF% cutoff points revealed a higher prevalence of obesity than BMI cutoff points. BMI misclassified 40.6% of participants, and optimal cutoff points yielding highest area under the curve were 24 kg/m2 and 24.3 kg/m2 for males and females, respectively. The study underscores the importance of using accurate and comprehensive diagnostic tools such as whole-body DEXA scans to assess obesity.

Dual energy X-ray absorptiometry produces larger measurement error in non-Hispanic Caucasians than Hispanics

Dual energy X-ray absorptiometry (DXA) is often used as a criterion measure in body composition research and in clinical settings for the estimate of body fat percent (%Fat). The accuracy of DXA for predicting %Fat has primarily been conducted in non-Hispanic populations. The purpose of this study was to determine the agreement of DXA-derived %Fat in Hispanic and non-Hispanic Caucasian adults. The sample consisted of Hispanic males (n=96) and females (n=102) and non-Hispanic Caucasian males (n=145) and females (n=161). The %Fat of a whole-body DXA scan was compared against a criterion 4-compartment (4C) model via constant error (CE=DXA - 4C model) and 95% limits of agreement. Also, a 2×2 factorial ANOVA, using CE as a dependent variable, was conducted to examine the main and interaction effects of sex and ethnicity. When compared to the 4C model, DXA overestimated %Fat by 4.0% in Hispanics and 5.5% in non-Hispanic Caucasians (all p<0.05). The 95% limits of agreement ranged from ±5.5% to ±5.9% for all group comparisons. The 2×2 factorial ANOVA indicated the CE was greater in non-Hispanic Caucasians than Hispanics (CE difference=1.5%; p<0.05). Our findings revealed that DXA significantly overestimates %Fat in both populations (Hispanics and non-Hispanic Caucasians), when compared to a 4C model, regardless of sex (male or female). However, the error is more profound in non-Hispanic Caucasian adults. It is worth nothing that DXA may be useful for tracking changes in body composition that occur throughout a lifestyle intervention. Nonetheless, practitioners should be aware that the estimate of %Fat from DXA may be larger than the actual values obtained from a 4C model.

O-086 Assisted reproductive technology does not influence body mass index (BMI) in a cohort of 606 children aged 6-9 years

Abstract Study question Is BMI in children conceived after frozen embryo transfer different from children conceived after fresh embryo transfer and after natural conception? Summary answer BMI in children conceived after frozen embryo transfer was similar to BMI in children conceived after fresh embryo transfer or children born after natural conception. What is known already Children conceived after frozen embryo transfer (FET) have higher risk of being born large for gestational age (LGA) than children conceived after natural conception (NC). Generally, being born LGA increases the risk of obesity in childhood. Childhood BMI is strongly associated with obesity and cardiometabolic disease and mortality in adulthood. The long-term effects of ART on the metabolic health of the offspring and the underlying mechanisms are scarcely explored. However, it has been proposed that ART may induce epigenetic variations around fertilization, implantation, and early embryonic stages that may influence size at birth. Study design, size, duration The study “Health in Childhood following Assisted Reproductive Technology” (HiCART) includes 606 singletons (292 boys, 314 girls) – 200 conceived after FET; 203 after fresh-ET; and a random sample of 203 naturally conceived children matched for age and sex. All children were born in Eastern Denmark from 2009-2013 and had a clinical examination performed at the Copenhagen University Hospital - Rigshospitalet when they were 6-9 years of age. Participants/materials, setting, methods The children underwent a clinical examination with anthropometric measurements, whole-body dual-energy x-ray absorptiometry-scan (DXA), pubertal staging, and a blood sample. All anthropometric measurements were converted to standard deviation scores (SDS) using a Danish reference. Parents filled in a questionnaire regarding the pregnancy and the current health of the child and themselves. Maternal, obstetric and neonatal data from the national ART and birth registry were obtained. Main results and the role of chance Children conceived after FET had higher birthweight SDS (0.20SDS, 1.09SD) than children conceived after fresh-ET (-0.22SDS, 1.00SD), p &amp;lt; 0.001 and children conceived naturally (-0.16SDS, 1.09SD), p = 0.001. Mothers conceiving naturally were younger and had higher parity than mothers conceiving after ART. The three groups were similar regarding pregestational maternal BMI and gestational age. Puberty had started in 57 children (54 girls), evenly distributed among the groups. There were no differences in height SDS between FET (0.25SDS, 1.00SD) compared to fresh-ET (0.17SDS, 0.96SD), p = 0.50 and compared to NC (0.07 SDS, 1.06SD), p = 0.11 or in weight SDS between FET (0.22SDS, 1.07SD) compared to fresh-ET (0.10 SDS, 1.06SD), p = 0.22 and compared to NC (0.14SDS, 1.00SD), p = 0.43. Similarly, no differences were found in BMI SDS between FET (0.16SDS, 1.16SD) compared to fresh-ET (0.04SDS, 1.10SD), p = 0.25 and compared to NC (0.20SDS, 1.01SD), p = 0.80. Our primary endpoint BMI SDS remained non-significant after adjustment for child sex, age and birthweight SDS, parity, maternal BMI and smoking in pregnancy. Limitations, reasons for caution The sample size was decided to be able to detect a difference of 0.3 SDS in childhood BMI, corresponding to a 3.4% increased mortality hazard. Thus, smaller differences in BMI SDS may be overlooked. As the participation rate was between 18-42% in the three groups, selection bias cannot be excluded. Wider implications of the findings The increased birth weight in children conceived after FET did not translate into a difference in BMI in this large cohort. Since BMI in childhood is a strong biomarker of cardiometabolic disease later in life, the findings are reassuring and may reduce concerns associated with the long-term consequences of FET. Trial registration number NCT03719703

Sarcopenia and Fat Mass in Children With Chronic Liver Disease and Its Impact on Liver Transplantation.

Children with end-stage chronic liver disease undergoing assessment for LT were recruited into an observational longitudinal study. Anthropometry and body composition (BC; whole-body dual-energy x-ray absorptiometry scan) were assessed before and, on average, 1 year after LT. Eleven children (6 females:5 males) were assessed (4.7 to 17.2 years; median, 9.9) at baseline. Nine children went on to have an LT. The aspartate aminotransferase-to-platelet ratio index had a significant positive correlation with trunk lean mass and trunk lean mass index (LMI) SD score (SDS). At baseline, 4 patients were sarcopenic with appendicular LMI SDS less than -1.96. All fat mass and fat mass index (FMI) SDSs were within the normal range (above -1.96). There was a strong negative correlation between FMI SDS and height SDS. After transplant, there was a significant reduction in trunk LMI from 1.20 to -0.51 (95% CI, 1.03-2.4; P < 0.01). Body mass index SDS had a negative correlation with days to discharge after transplant. The majority of patients discharged after 16 days were sarcopenic. One year after transplantation, all patients were alive with normal graft function regardless of BC before LT. FMIs were normal regardless of LMIs and correlated negatively with height. BC was related to days to discharge after LT but not to outcomes a year after LT.

Foot posture index and body composition measures in children with and without developmental coordination disorder.

BackgroundFoot posture which forms the distal supporting structure influences on postural stability. Children with developmental coordination disorder (DCD) who are more likely to be overweight or obese may present with flat foot with symptoms that affect daily activities. The aim of this study was to compare the foot posture and body composition measures between children with and without DCD. In addition, this study aimed to investigate the relationship between foot posture and fat percentage.MethodsFifty-nine children with DCD (mean age = 8.07±1.10) and sixty-two typically developing children (mean age = 7.97±1.05) were recruited to the DCD and control group respectively. All children received a foot posture assessment and a whole-body dual-energy X-ray absorptiometry (DXA) scan. Foot Posture Index 6 (FPI-6) total scores, sub-scores and lower limb body composition measures including fat mass, lean mass, total mass, fat percentage and fat mass index were measured.ResultsChildren with DCD revealed a significantly higher FPI-6 left (1.12; 95% CI: 0.172, 2.061) and right (1.15; 95% CI: 0.218, 2.079) total score. FPI-6 sub-scores (talar head palpation and abduction/adduction forefoot on rearfoot) illustrated significant differences between children with and without DCD. Children with DCD had a significantly higher total fat mass (1247.48g; 95% CI: 121.654, 2373.304), total fat percentage (1.82%; 95% CI: 0.115, 3.525) and fat mass index (0.56kg/m2; 95% CI: 0.036, 1.069). There was a significant relationship between FPI-6 right total score and total fat percentage.ConclusionThe findings of this study showed that children with DCD exhibited significantly more pronated foot posture and higher body composition measures compared to typically developing children. Moreover, with FPI-6 right total score significantly related to the total fat percentage, it may require more than just detecting abnormal foot structures in children with DCD but also promoting a healthy lifestyle to prevent obesity.

Differences in the obesity screening ability of 19 anthropometric parameters in young Japanese females: Comparisons of direct measurements, conventional and novel indices

Aim: The present study aimed to examine the usefulness of anthropometric parameters for obesity screening in young Japanese females by assessing their associations with indicators of adiposity obtained from a dual energy x-ray absorptiometry (DXA). Methods: Screening ability of 19 anthropometric parameters was examined using a total of 50 young Japanese females who completed detailed anthropometry and a whole-body DXA scan. Anthropometric parameters were categorized into 1) measured variables, 2) conventional indices, and 3) novel indices and their correlations with body fat variables obtained from DXA were investigated. Using a percentage body fat (%BF) of 30.0% as a cut-off point of obesity, the Area Under the Curve (AUC) was observed from the Receiver Operating Characteristics (ROC) analysis and cut-off points of anthropometric parameters were determined. Results: While body mass correlated highly with total fat tissue mass in this sample (r = 0.847), body mass index (BMI) and waist circumference (WC) correlated most strongly with trunk fat and android fat tissues respectively (r = 0.820 and 0.865). However, all body composition variables were correlated with the sum of eight skinfolds (Sum8SF) if %BF was used (r ranged 0.672 – 0.834). Among anthropometric parameters examined, Ʃ8SF showed highest AUC for %BFTotal, %BFGynoid and %BFIAAT while Ʃ2SF and abdominal circumference (AbC) showed highest AUC for %BFTrunk and %BFAndroid respectively. Conclusion: Directly measured variables and conventional indices showed moderate to strong correlations with results from DXA. However, the sum of skinfolds, particularly Sum8SF, showed stronger correlations and superior screening ability for obesity. Although many novel indices have been utilized to screen obesity and metabolic abnormalities, observed results indicated that these indices may not necessarily better than measured values or conventional indices. Further investigations to confirm proposed cut-off points are warranted.

Comparison between handheld ultrasound and regional and whole-body dual energy x-ray absorptiometry (DXA) for body fat assessment.

To determine the extent of agreement between a handheld ultrasound (US) attached to an android tablet and the reference method dual energy x-ray absorptiometry (DXA) for the measurement of adiposity. A whole-body DXA scan and abdominal adipose tissue thickness measurements using a handheld US were obtained from 104 adults (63 females, 41 males). Body fat percent (BF%), total fat mass (kg), and trunk fat mass (kg) were obtained from DXA. Subcutaneous adipose tissue (SAT), superficial subcutaneous adipose tissue (SSAT), and deep subcutaneous adipose tissue (DSAT) thickness were obtained from US. Sex-specific total fat mass, trunk fat mass, and BF% estimates by US were compared with DXA. Spearman's correlations and Bland-Altman plots were used to assess agreement between the methods. US SAT correlated strongly with total fat mass for both females (rs=0.74) and males (rs=0.87) as did trunk fat mass (females, rs=0.81; males, rs=0.83); as did SSAT and DSAT (females: rs=0.65 and rs=0.66; males: rs=0.63 and rs=0.85, respectively, all p-values < 0.0001). Bland-Altman plots demonstrated strong agreement for total and trunk fat mass for both males and females. For BF%, acceptable limits of agreement were observed for males but not for females, substantial proportional bias as indicated by a negative slope was noted for BF% using SAT (r=-0.298, p=0.0177). The handheld US and technique to analyze abdominal adipose tissue thickness showed strong agreement with DXA results and generated highly comparable estimates for total and trunk fat mass for both sexes.

Too Tall for the DXA Scan? Contributions of the Feet and Head to Overall Body Composition

Accurate assessment of total body composition in tall (>1.96m) individuals using dual energy x-ray absorptiometry (DXA) scans is problematic due to current height restrictions of the scan table. The aim of this investigation was to quantify absolute and relative contributions of fat, bone and lean mass, of the feet and head regions, to whole-body composition DXA scan totals. Whole-body DXA scans were performed in collegiate athletes. Athlete DXA scans were included in data analyses if the entire body fit within the confines of scan table area. The feet region of interest (ROI) was delineated at the ankle joint mortise, marked superiorly by the inferior margin of the tibial plafond and encompassing all inferior anatomical structures. The head region was calculated by the DXA scan software. Both absolute (kg) and relative (feet/whole-body x 100 = feet mass %) contributions to body composition were calculated. Data presented as mean±SD. 132 National Collegiate Athletic Association (NCAA) athletes (85 female) underwent DXA scans which met the inclusion criteria. The feet region represented: 1.9±0.3kg (2.6±0.3%) of total mass; 0.4±0.3kg (2.6±0.5%) of fat mass; 1.3±0.3kg (2.5±0.3%) of lean mass; and 0.14±0.0kg (5.4±0.6%) of bone mineral content (BMC). The head region represented: 4.8±0.5kg (6.9±0.8%) of total mass; 1.2±0.2kg (8.2±3.0%) of fat mass; 3.2±0.5kg (6.1±0.9%) of lean mass; and 0.48±0.07kg (18.7±2.7%) of BMC. Significant negative relationships were found between head% versus whole-body BMC (r=-0.54;p < 0.0001), lean mass (r=-0.57;p<0.0001), and fat mass (r=-0.81;p<0.0001) and between feet% versus fat mass (r=-0.68;p<0.0001). A significant positive relationship was noted between feet% versus whole-body BMC (r=0.18;p=0.04) but not versus lean mass (r=0.15;p=0.09). Removing the feet from whole-body composition analyses reduces lean, fat and bone mass compartment totals by 3%-5%. Removing the head region reduces body composition compartments by 6%-19%, from whole-body DXA scan totals.

Use of Dual-Energy X-Ray Absorptiometry to Assess Soft Tissue Composition in Breast Cancer Survivors With and Without Lymphedema.

Background: In patients with lymphedema (LE), in addition to hand dominance, between-group comparisons of interlimb soft tissue differences need to account for differences in whole-body adiposity, measured directly by dual energy X-ray absorptiometry (DXA) or indirectly by body mass index. No study has evaluated the effects of hand dominance and whole-body adiposity on limb composition in patients with LE. This study's purpose was to compare soft tissue composition of affected and unaffected limbs of women with breast cancer, who did and did not have LE, controlling for dominance and percent body fat. Methods and Results: Whole-body DXA scans were acquired and included measures of percent body fat, upper limb total mass, upper limb fat mass, and upper limb fat-free mass. Participants were classified into one of three groups: women without LE; women with only subjective LE; and women with objective signs of LE at the time of assessment. Differences among the LE groups were evaluated using analysis of variance (ANOVA) and Chi-square analyses. Analysis of covariance (ANCOVA) was used to control for percent body fat and for the affected limb dominance. Compared to women without LE, women with objective signs of LE have greater total limb mass, fat mass, and fat-free mass in their affected limbs, independent of affected side dominance and percent body fat. In addition, the interlimb differences in total mass, fat mass, and fat-free mass were greater for the women with objective signs of LE, compared to the other two groups. Conclusions: DXA is useful in identifying soft tissue changes in patients with LE. Given that limb circumferences measure only changes in limb volume and that bioimpedance provides estimates of extracellular fluid, DXA has the advantage of being able to estimate the volumes of specific tissues in the limb.

In vivo assessment of OXPHOS capacity using 3\xa0T CrCEST MRI in Friedreich\u2019s ataxia

BackgroundFriedreich’s ataxia (FRDA) is a neurodegenerative disease caused by decreased expression of frataxin, a protein involved in many cellular metabolic processes, including mitochondrial oxidative phosphorylation (OXPHOS). Our objective was to assess skeletal muscle oxidative metabolism in vivo in adults with FRDA as compared to adults without FRDA using chemical exchange saturation transfer (CrCEST) MRI, which measures free creatine (Cr) over time following an in-magnet plantar flexion exercise.MethodsParticipants included adults with FRDA (n = 11) and healthy adults (n = 25). All underwent 3-Tesla CrCEST MRI of the calf before and after in-scanner plantar flexion exercise. Participants also underwent whole-body dual-energy X-ray absorptiometry (DXA) scans to measure body composition and completed questionnaires to assess physical activity.ResultsWe found prolonged post-exercise exponential decline in CrCEST (τCr) in the lateral gastrocnemius (LG, 274 s vs. 138 s, p = 0.01) in adults with FRDA (vs. healthy adults), likely reflecting decreased OXPHOS capacity. Adults with FRDA (vs. healthy adults) also engaged different muscle groups during exercise, as indicated by muscle group-specific changes in creatine with exercise (∆CrCEST), possibly reflecting decreased coordination. Across all participants, increased adiposity and decreased usual physical activity were associated with smaller ∆CrCEST.ConclusionIn FRDA, CrCEST MRI may be a useful biomarker of muscle-group-specific decline in OXPHOS capacity that can be leveraged to track within-participant changes over time. Appropriate participant selection and further optimization of the exercise stimulus will enhance the utility of this technique.

Agreement Between A 2-Dimensional Digital Image-Based 3-Compartment Body Composition Model and Dual Energy X-Ray Absorptiometry for The Estimation of Relative Adiposity

The purpose of this study was to compare relative adiposity (%Fat) derived from a 2-dimensional image-based 3-component (3C) model (%Fat3C-IMAGE) and dual-energy X-ray absorptiometry (DXA) (%FatDXA) against a 5-component (5C) laboratory criterion (%Fat5C). 57 participants were included (63.2% male, 84.2% White/Caucasian, 22.5±4.7 yrs., 23.9±2.8 kg/m2). For each participant, body mass and standing height were measured to the nearest 0.1 kg and 0.1 cm, respectively. A digital image of each participant was taken using a 9.7 inch, 16g iPad Air 2 and analyzed using a commercially available application (version 1.1.2, made Health and Fitness, USA) for the estimation of body volume (BV) and inclusion in %Fat3C-IMAGE . %Fat3C-IMAGE and %Fat5C included measures of total body water derived from bioimpedance spectroscopy. The criterion %Fat5C included BV estimates derived from underwater weighing and bone mineral content measures via DXA. %FatDXA estimates were calculated from a whole-body DXA scan. A standardized mean effect size (ES) assessed the magnitude of differences between models with values of 0.2, 0.5, and 0.8 for small, moderate, and large differences, respectively. Data are presented as mean ± standard deviation. A strong correlation (r = 0.94, p <.001) and small mean difference (ES = 0.24, p <.001) was observed between %Fat3C-IMAGE (19.20±5.80) and %Fat5C (17.69±6.20) whereas a strong correlation (r = 0.87, p <.001) and moderate-large mean difference (ES = 0.70, p <.001) was observed between %FatDXA (22.01±6.81) and %Fat5C. Furthermore, %Fat3C-IMAGE (SEE = 2.20 %Fat, TE= 2.6) exhibited smaller SEE and TE than %FatDXA (SEE = 3.14 %Fat, TE = 5.5). The 3C image-based model performed slightly better in our sample of young adults than the DXA 3C model. Thus, the 2D image analysis program provides an accurate and non-invasive estimate of %Fat within a 3C model in young adults. Compared to DXA, the 3C image-based model allows for a more cost-effective and portable method of body composition assessment, potentially increasing accessibility to multi-component methods.

A pose-independent method for accurate and precise body composition from 3D optical scans.

The aim of this study was to investigate whether digitally re-posing three-dimensional optical (3DO) whole-body scans to a standardized pose would improve body composition accuracy and precision regardless of the initial pose. Healthy adults (n = 540), stratified by sex, BMI, and age, completed whole-body 3DO and dual-energy X-ray absorptiometry (DXA) scans in the Shape Up! Adults study. The 3DO mesh vertices were represented with standardized templates and a low-dimensional space by principal component analysis (stratified by sex). The total sample was split into a training (80%) and test (20%) set for both males and females. Stepwise linear regression was used to build prediction models for body composition and anthropometry outputs using 3DO principal components (PCs). The analysis included 472 participants after exclusions. After re-posing, three PCs described 95% of the shape variance in the male and female training sets. 3DO body composition accuracy compared with DXA was as follows: fat mass R2 = 0.91 male, 0.94 female; fat-free mass R2 = 0.95 male, 0.92 female; visceral fat mass R2 = 0.77 male, 0.79 female. Re-posed 3DO body shape PCs produced more accurate and precise body composition models that may be used in clinical or nonclinical settings when DXA is unavailable or when frequent ionizing radiation exposure is unwanted.

Metabolic Syndrome in Male Survivors of Pediatric Allogeneic Hematopoietic Stem Cell Transplantation: Impact of Total Body Irradiation, Low-Grade Inflammation, and Hypogonadism

Metabolic syndrome (MetS) is a growing concern in survivors of pediatric hematopoietic stem cell transplantation (HSCT), but little is known about the underlying mechanisms. This study aimed to determine the prevalence and clinical presentation of MetS in male long-term survivors of pediatric HSCT and to investigate predisposing factors, including low-grade inflammation, altered fat distribution, and low testosterone levels. We included 98 survivors age 19 to 47 years at a median follow-up of 18 years (range, 8 to 35 years) after pediatric HSCT. MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The prevalence and clinical manifestations of MetS were compared between our cohort and a control group of males from the background population (n=4767). Fat distribution was assessed by android/gynoid ratio from a whole-body dual-energy X-ray absorptiometry scan. Systemic inflammation was evaluated by IL-6 and high-sensitivity C-reactive protein (hsCRP). Serum testosterone levels were measured in morning samples. The prevalence of MetS was 30%, corresponding to the prevalence in the 50- to 80-year-old males from the background population. In individuals with MetS, hyperglycemia was more frequent in the HSCT survivors compared with age-matched controls with MetS (76% versus 20%; P < .001), whereas hypertension was more dominant in the control group with MetS (69% versus 93%; P=.01). In addition, normal or low body mass index was more commonly observed among HSCT survivors with MetS compared with age-matched controls with MetS (41% versus 11%; P=.002). MetS was more often associated with total body irradiation (TBI) compared with chemotherapy regimens (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.2 to 24.4; P=.02), lower testosterone levels (OR, 5.4; 95% CI, 1.3 to 23.6; P=.02), higher IL-6 levels (OR, 1.8; 95% CI, 1.2 to 2.8; P=.004), and higher hsCRP levels (OR, 1.8; 95% CI, 1.3 to 2.6; P < .001) (estimates per 2-fold increase). In addition, an increased android/gynoid (AG) fat ratio was strongly associated with MetS (OR, 2.1; 95% CI, 1.5 to 2.9; P < .001), even though only 7% of patients met the criteria for increased abdominal circumference. Our results indicate an increased risk of MetS in early adulthood after pediatric HSCT. The clinical manifestations differed from those seen in age-matched controls with MetS, indicating different pathophysiology driven by hyperglycemia, altered fat distribution (despite no clinical abdominal obesity), and low-grade inflammation. Risk factors included TBI-based conditioning and low testosterone levels. These results underline the importance of continuous clinical assessment of the cardiometabolic risk profile and stress the presence of important dissimilarities in the pathophysiology of MetS in HSCT survivors compared with the background population.

Accounting for Surgical Confounding Factors Affecting Dual-Energy X-ray Absorptiometry in a Large Clinical Trial

Joint replacements are among the most common orthopedic procedures performed in the U.S. and will continue to increase with the aging population. It is therefore necessary to account for these and other confounding factors, such as breast implants, when performing dual-energy X-ray absorptiometry (DXA) measurements. Whole-body DXA scans were performed in 771 participants (men ≥50 yr and women ≥55 yr) to assess bone mineral density (BMD) and body composition (fat and lean mass). In the DXA scan analyses of participants with internal metal, these affected regions of interest were replaced with measures from the unaffected, contralateral side, consistent with recommendations of the International Society for Clinical Densitometry. T-scores and Z-scores were recalculated using default sex and ethnicity-matched databases. We also explored effects of breast implants on bone density and body composition analyses. Approximately 13.1% of participants had internal metal artifacts at baseline. Replacing metal artifacts with the unaffected, contralateral side decreased the whole-body BMD by an average of 8.1% (SEM 0.84%; n = 67). In participants with unilateral hip (n = 17) and knee replacements (n = 20), BMD was decreased by an average of 14.1% (SEM 1.7%) and 11.2% (SEM 1.1%), respectively. Fat and lean mass were not significantly affected by metal artifacts, as differences between values with and without metal were within 1%. Two participants had bilateral breast implants, and in a separate trial, one participant had a unilateral breast implant. Bone mineral content (BMC) in the region with the breast implant was 5.8 times higher than the contralateral side, and whole-body BMC was increased by 4.7%. Metal artifacts and breast implants can confound DXA whole-body bone but not fat and lean results. It is therefore important in clinical studies to account for these factors to detect physiologically relevant differences in bone measures.

The association between incident vertebral deformities, health-related quality of life and functional impairment: a 10.7-year cohort study.

To describe associations between incident VD and changes in HRQoL and functional ability in older adults over 10.7 years. Participants (n = 780) underwent whole-body dual-energy X-ray absorptiometry (DXA) scans at baseline, 2.5, 5.1 and 10.7 years later. VD was defined as ≥ 25% reduction in anterior height relative to posterior height of vertebrae from T4 to L4. An incident VD was defined as a new VD at any follow-up visit. Assessment of Quality of Life (AQoL-4D) questionnaire and Health Assessment Questionnaire-Disability Index (HAQ-DI) were used to assess HRQoL and functional impairment. Changes in AQoL and HAQ-DI associated with incident VD were analysed using multilevel mixed-effects linear regression. Log binomial regression was used to examine clinically relevant changes and effects of severity and number of VD. The incidence of VD was 37% over 10.7 years. In women, incident VDs were associated with annual reduction in AQoL utility score (β = -0.005, 95% CI -0.008 to -0.002). Men had increased risk of clinically significant reduction in HAQ-DI (IRR = 1.76, 95% CI 1.07-2.89). Men had increased risk of clinically important functional impairment with increasing severity (IRR 1.76, 95% CI 1.04-2.95 for mild vs IRR 1.98, 95% CI 1.13-3.47 for moderate to severe VD) as well as number of incident VD (IRR 1.85, 95% CI 1.17-2.93 for one vs IRR 1.88, 95% CI 0.94-3.78 for ≥ 2 VDs). Such associations were not observed in women. Incident VDs are associated with clinically significant functional impairment in men, and reduction in overall HRQoL in older women. Increasing severity and number of incident VDs are associated with clinically meaningful functional impairment in men, but not women.

Reduced Peak Bone Mass in Young Adults With Low Motor Competence.

Although suboptimal bone health has been reported in children and adolescents with low motor competence (LMC), it is not known whether such deficits are present at the time of peak bone mass. We examined the impact of LMC on bone mineral density (BMD) in 1043 participants (484 females) from the Raine Cohort Study. Participants had motor competence assessed using the McCarron Assessment of Neuromuscular Development at 10, 14, and 17 years, and a whole-body dual-energy X-ray absorptiometry (DXA) scan at 20 years. Bone loading from physical activity was estimated from the International Physical Activity Questionnaire at the age of 17 years. The association between LMC and BMD was determined using general linear models that controlled for sex, age, body mass index, vitamin D status, and prior bone loading. Results indicated LMC status (present in 29.6% males and 21.9% females) was associated with a 1.8% to 2.6% decrease in BMD at all load-bearing bone sites. Assessment by sex showed that the association was mainly in males. Osteogenic potential of physical activity was associated with increased BMD dependent on sex and LMC status, with males with LMC showing a reduced effect from increasing bone loading. As such, although engagement in osteogenic physical activity is associated with BMD, other factors involved in physical activity, eg, diversity, movement quality, may also contribute to BMD differences based upon LMC status. The finding of lower peak bone mass for individuals with LMC may reflect a higher risk of osteoporosis, especially for males; however, further research is required. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Lower insulin sensitivity remains a feature of children born very preterm.

The first report of children born very preterm (<32 weeks of gestation) having insulin resistance was made 16 years ago. However, neonatal care has improved since. Thus, we aimed to assess whether children born very preterm still have lower insulin sensitivity than term controls. Participants were prepubertal children aged 5 to 11 years born very preterm (<32 weeks of gestation; n = 51; 61% boys) or at term (37-41 weeks; n = 50; 62% boys). Frequently sampled intravenous glucose tolerance tests were performed, and insulin sensitivity was calculated using Bergman's minimal model. Additional clinical assessments included anthropometry, body composition using whole-body dual-energy X-ray absorptiometry scans, clinic blood pressure, and 24-hour ambulatory blood pressure monitoring. Children born very preterm were 0.69 standard deviation score (SDS) lighter (P < .001), 0.53 SDS shorter (P = .003), and had body mass index 0.57 SDS lower (P = .003) than children born at term. Notably, children born very preterm had insulin sensitivity that was 25% lower than term controls (9.4 vs 12.6 × 10-4 minutes-1 ·[mU/L]; P = .001). Other parameters of glucose metabolism, including fasting insulin levels, were similar in the two groups. The awake systolic blood pressure (from 24-hour monitoring) tended to be 3.1 mm Hg higher on average in children born very preterm (P = .054), while the clinic systolic blood pressure was 5.4 mm Hg higher (P = .002). Lower insulin sensitivity remains a feature of children born very preterm, despite improvements in neonatal intensive care. As reported in our original study, our findings suggest the defect in insulin action in prepubertal children born very pretermis primarily peripheral and not hepatic.

Relationship between Skeletal Muscle Mass, Bone Mineral Density, and Trabecular Bone Score in Osteoporotic Vertebral Compression Fractures.

Study DesignA retrospective observational study was performed.PurposeWe investigated the relationships between skeletal muscle mass, bone mineral density (BMD), and trabecular bone score (TBS) in patients with osteoporotic vertebral compression fractures (VCFs).Overview of LiteratureThe TBS has attracted attention as a measurement of trabecular bone microarchitecture. It is derived from data obtained using dual-energy X-ray absorptiometry (DXA) and is a reported indicator of VCFs, and its addition to the Fracture Risk Assessment Tool increases the accuracy of fracture prediction.MethodsBMD, skeletal muscle mass, and TBS were measured in 142 patients who visited Shimoshizu National Hospital from April to August 2019. Patients were divided into a VCF group and a non-VCF group. Whole-body DXA scans were performed to analyze body composition, including appendicular skeletal muscle mass index (SMI; lean mass [kg]/height [m2]) and BMD. The diagnostic criteria for sarcopenia was an appendicular SMI <5.46 kg/m2. A logistic regression analysis was conducted to identify the risk factors for VCFs.ResultsThe significant (p<0.05) findings (VCF group vs. non-VCF group, respectively) included age (79 vs. 70 years), femoral BMD (0.50 vs. 0.58 g/cm2), TBS (1.25 vs. 1.29), and lower limb muscle mass (8.6 vs. 9.9 kg). The VCF group was significantly older and had a lower femur BMD and decreased leg muscle mass than the non-VCF group. Based on the multiple logistic regression analysis, lower femoral BMD and decreased leg muscle mass were identified as risk factors for vertebral fracture independent of age, but the TBS was not.ConclusionsPatients with VCFs had low BMD, a low TBS, and low skeletal muscle mass. Lower femoral BMD and decreased leg muscle mass were identified as risk factors for VCFs independent of age, whereas the TBS was not identified as a risk factor for VCFs.