Body Dual-energy X-ray Absorptiometry Research Articles

8740 Visceral Adipose Tissue Assessment in Patients With Mild Autonomous Cortisol Secretion Using Dual-Energy X-Ray Absorptiometry: A Cross-Sectional Study

Abstract Disclosure: J. Saini: None. C.D. Zhang: None. V. Fell: None. E. Atkinson: None. S. Achenbach: None. I. Bancos: None. Background: Several studies employing computed tomography (CT) scans for body composition measurements have reported lower muscle mass and a higher proportion of visceral fat in patients with mild autonomous cortisol secretion (MACS) compared to referent subjects. While a CT scan assesses visceral adipose tissue (VAT) at a single slice level (L3), no studies have evaluated the overall VAT in patients with MACS using Dual-Energy X-ray absorptiometry (DXA). Objective: To determine the impact of MACS on VAT using DXA scan as compared to referent subjects. Methods: We conducted a single-center cross-sectional study of adults with 75 MACS and 75 referent subjects. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test in patients with adrenal adenomas and no features of overt hypercortisolism. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. All the participants underwent a full body DXA scan between 04/2019 and 07/2022. We applied the CoreScan software to estimate the (1) total lean and fat mass (2) visceral fat mass and volume (3) lean android, fat android, and android mass, and compared measurements of patients and referent subjects using linear regression models adjusted for sex and BMI. Results: A total of 75 patients with MACS (median age 57.0 years, IQR 47.8-65.6, 67% women) and 75 referent subjects (median age 57.6 years, IQR 49.1-65.8, 67% women) were included. Patients had a higher BMI compared to referent subjects (median 31.7 kg/m2, IQR 27.4-37.9 vs 28.7, IQR, 25.4-33.8, P=0.004). The median post-DST cortisol in patients was 3.1 mcg/dL (IQR, 2.2-5.2). When compared to referent subjects, and after adjustment for sex and BMI, patients had a similar total body fat (estimate=846, p-value=0.28) and lean mass (estimate=-201, p-value=0.83), similar android fat mass (estimate=59, p-value=0.64) but lower gynoid fat mass (estimate=400, 0.007). Notably, sex and BMI-adjusted analysis also showed that patients had a higher VAT fat mass (estimate= -225, p-value=0.084) and a higher VAT fat mass/total mass ratio (estimate= -0.007, p-value=0.026). Conclusions: When adjusted for BMI and sex, patients with MACS do not demonstrate differences in overall fat and lean mass. However, we showed that MACS is associated with increased visceral adiposity, a known cardiovascular risk factor. Body composition assessment by DXA could be a safer and less expensive alternative in the evaluation and follow-up of patients with MACS. Presentation: 6/2/2024

Changes In Dual-energy X-ray Absorptiometry Body Composition Scores In Females Following Exercise-induced Body Fluid Redistribution

Changes In Dual-energy X-ray Absorptiometry Body Composition Scores In Females Following Exercise-induced Body Fluid Redistribution

Impact of Acute Dietary and Exercise Manipulation on Next Day RMR Measurements and DXA Body Composition Estimates.

To investigate the effects of acute diet and exercise manipulation on resting metabolic rate (RMR) measurement variability and dual energy x-ray absorptiometry (DXA) body composition estimates. 10 male and 10 female endurance athletes (12 cyclists, 5 triathletes, 4 runners) of Tier 2 (n = 18) to Tier 3 (n = 2) calibre underwent five conditions using a Latin square counterbalance design. For 24 hours, athletes consumed a diet providing excessive energy availability (75 kcal‧kg fat free mass (FFM)-1) without exercise (GEArest), high energy availability (45 kcal‧kg FFM-1) without (HEArest) or with exercise (HEAex), or low-energy availability (15 kcal‧kg FFM-1) without (LEArest) or with exercise (LEAex). Exercise involved two bouts of cycling (morning bout: 149 ± 34 min at 55% of maximal aerobic capacity (VO2 max); afternoon bout: 60 min at 65% of VO2 max) that resulted in a cumulative exercise energy expenditure of 30 kcal‧kg FFM-1. The following day, RMR and DXA measurements occurred after a 10-hour fast and 12-hours post-exercise. There were no sex differences in relative RMR (p = 0.132) nor effects of any of the five conditions on RMR (p = 0.353). For both male and female athletes, FFM estimates were decreased following the LEArest (-0.84 ± 0.66 kg; p = 0.001) and LEAex (-0.65 ± 0.86 kg; p = 0.016) conditions compared to the GEArest condition and following the LEArest (-0.73 ± 0.51 kg; p = 0.001) and LEAex (-0.54 ± 0.79 kg; p = 0.024) conditions compared to the HEAex condition. There was no effect of condition on fat mass estimates (p = 0.819). Acute periods of diet and exercise manipulation did not create artifacts in next-day RMR measurements. However, as changes in estimates of FFM were seen, diet and exercise should be controlled in the 24-hours prior to DXA scans.

The Subcutaneous Adipose Microenvironment as a Determinant of Body Fat Development in Polycystic Ovary Syndrome.

Adipose steroid metabolism modifies body fat development in polycystic ovary syndrome (PCOS). To determine whether subcutaneous (SC) abdominal adipose aldo-keto reductase 1C3 (AKR1C3; a marker of testosterone generation) is increased in normal-weight women with PCOS vs age- and body mass index (BMI)-matched normoandrogenic ovulatory women (controls) and is related to SC abdominal adipose activator protein-1 (AP-1; a marker of adipocyte differentiation) and/or androgen receptor (AR) protein expression in predicting fat accretion. Prospective cohort study. Academic center. Eighteen normal-weight PCOS women; 17 age- and BMI-matched controls. Circulating hormone/metabolic determinations, intravenous glucose tolerance testing, total body dual-energy x-ray absorptiometry, SC abdominal fat biopsy, immunohistochemistry. Clinical characteristics, hormonal concentrations, body fat distribution, SC adipose AKR1C3, AR, and AP-1 protein expression. Women with PCOS had significantly higher serum androgen levels and greater android/gynoid fat mass ratios than controls. SC adipose AKR1C3, AR, and AP-1 protein expressions were comparable between the study groups, but groups differed in correlations. In PCOS women vs controls, SC adipose AKR1C3 protein expression correlated positively with android and gynoid fat masses and negatively with SC adipose AP-1 protein expression. SC adipose AR protein expression correlated negatively with fasting serum free fatty acid and high-density lipoprotein levels. In both study groups, SC adipose AKR1C3 protein expression negatively correlated with serum cortisol levels. In normal-weight PCOS women, SC abdominal adipose AKR1C3 protein expression, in combination with intra-adipose AP-1 and AR-dependent events, predicts fat accretion in the presence of physiological cortisol levels.

Semaglutide as a promising treatment for hypothalamic obesity: a six-month case series on four females with craniopharyngioma.

Patients with hypothalamic pathology often develop hypothalamic obesity, causing severe metabolic alterations resulting in increased morbidity and mortality. Treatments for hypothalamic obesity have not proven very effective, although the glucagon-like peptide-1 receptor agonist semaglutide has been shown to have positive effects. We examined semaglutide's effect on weight loss in a sample of patients with hypothalamic obesity. Four female patients with hypothalamic obesity resulting from treatment of craniopharyngiomas were treated with semaglutide for six months. Whole Body Dual-energy x-ray absorptiometry scans were performed, and blood samples drawn at baseline and after six months. Semaglutide dosages were increased monthly along with tracking of body weight and eating behavior (Three Factor Eating Questionnaire, TFEQ-R18). BMI was reduced in all cases, with an average of 7.9 BMI (range: 6.7 to 10.1) corresponding to a weight loss of 17.0% (range: 11.3-22.4%) or 20.2kg (range 16.2kg to 23.4kg). We found a comparable reduction in total fat mass (17.2%, p = 0.006) and lean mass (16.0%, p = 0.05), whereas bone mass was unchanged (2.6%, p = 0.12). All cases reported an increase in energy levels, improved mobility and physical activity. Unfavorable eating behaviors were reduced after 1 month of treatment (emotional eating - 41 points, p = 0.02, uncontrolled eating - 23 points, p = 0.11). HbA1c and total cholesterol were significantly reduced (p = 0.014 for both). Semaglutide is a promising and safe treatment option for HO, that improves eating behavior, reduces weight, and improves metabolic markers.

Development of the mineralisation of individual bones and bone regions in replacement gilts according to dietary calcium and phosphorus

Skeleton bones, distinguished by trabecular and cortical bone tissue content, exhibit varied growth and composition, in response to modified dietary calcium and phosphorus levels. The study investigated how gilts adapt their individual bone and bone region mineralisation kinetics in response to changing intake of Ca and P. A total of 24 gilts were fed according to a two-phase (Depletion (D) 60–95 and Repletion (R) 95–140 kg BW, respectively). During the D phase, gilts were fed either 60% (D60) or 100% (D100) of the estimated P requirement. Subsequently, during the R phase, half of the gilts from each D diet were fed either 100% (R100) or 160% (R160) of the estimated P requirement according to a 2 × 2 factorial arrangement. Bone mineral content (BMC) was assessed in the whole body, individual bones (femur and lumbar spine L2–L4), and bone regions (head, front legs, trunk, pelvis, femur, and hind legs) every 2 weeks using dual-energy X-ray absorptiometry (DXA). At 95 kg BW, gilts fed D60 showed reduced BMC and BMC/BW ratio in all studied sites compared to those fed D100 (P < 0.001). During the depletion phase, the allometric BW-dependent regressions slopes for BMC of D100 gilts remained close to 1 for all sites and did not differ from each other. In contrast, the slopes were lower in D60 gilts (P < 0.05), with an 18% reduction in the whole body, except for the front and hind legs, femur, and pelvis, which exhibited higher reductions (P < 0.05). At 140 kg BW, BMC and BMC/BW ratio of all studied sites were similar in gilts previously fed D60 and D100, but higher in R160 than in R100 gilts (P < 0.05), except for front and hind legs. During the repletion phase, the allometric BW dependent regressions slopes for BMC were lower (P < 0.05) in R100 than in R160 gilts (for whole body −10%; P < 0.01) except for front and hind legs, femur, and pelvis. In conclusion, bone demineralisation and recovery followed similar trends for all measured body sites. However, the lumbar spine region was most sensitive whereas the hind legs were least sensitive. These data suggest that using bone regions such as the head and forelegs that can be collected easily at the slaughterhouse may be a viable alternative to whole body DXA measurement.

The useful lean tissue and appendicular skeletal muscle mass indices related to physical performance in patients undergoing hemodialysis

BACKGROUND: Low muscle quantity commonly seen in patients undergoing hemodialysis (HD) is the key contributor of declined physical performance and increases the risk of morbidity and mortality. However, how to normalize muscle mass for operational criteria in this population remains unknown. OBJECTIVE: To identify the clinically useful whole body lean tissue mass (LTM) and appendicular skeletal muscle mass (ASM) indices pertinent to physical performance in patients undertaking HD. METHODS: Whole body LTM in 38 and ASM in 22 patients undergoing HD were measured by body composition monitor (BCM) and dual-energy X-ray absorptiometry (DXA), respectively. Physical performance was assessed by handgrip strength, the incremental shuttle walk test, sit-to-stand tests, gait speed, Short Physical Performance Battery and Duke Activity Status Index. Besides crude LTM and ASM, the other muscle indices were utilized normalizing for height, height squared, weight, body mass index (BMI), fat mass and body fat%. RESULTS: Regardless of BCM or DXA being used, the relationships between different muscle mass indices and physical function were not consistent. While the most useful LTM index which was strongly associated with physical function involved adjustment for height, the strongest (and most useful) ASM index was normalization for BMI. CONCLUSION: The superiority of adjustment for BMI or height (height2) recommended by international sarcopenia consensus is also suitable for patients undergoing HD. Patients’ BMI or fat mass should be considered in estimating prevalence of sarcopenia and evaluating relationship between muscle mass and physical performance.

Association of body image perception and (dis)satisfaction with adiposity in adults: The Pró-Saúde study.

Body image distortion and/or dissatisfaction may occur primarily due to body fat accumulation and/or distribution. The aim of this study was to evaluate the frequency of body image perception and (dis)satisfaction categories in adult men and women according to the adiposity classification. This is a cross-sectional study (n = 514; 33-79 years; 265 women) that is part of a prospective cohort (Pró-Saúde study). Adiposity measurements were determined by two methods: anthropometry, used to calculate the body mass index (BMI) and dual-energy X-ray absorptiometry (DXA), to estimate body fat percentage. Participants were grouped as "no excess adiposity" and "excess adiposity", considering BMI and body fat percentage (>30% for men, >40% for women). Perception and (dis)satisfaction with body image were evaluated using the Kakeshita scale, composed by 15 silhouettes, developed for the Brazilian population. Degree of distortion (perceived BMI - real BMI) and dissatisfaction (perceived BMI - desired BMI) were calculated. A high proportion of men (58.6%; 74.3%), and especially of women (82.6%; 86.8%), presented body size overestimation and dissatisfaction due to excess weight, respectively. A relevant fraction of the women (32.6%) and men (30.8%) who were dissatisfied due to excess weight did not present excess adiposity, especially if classified by DXA. Variability in degree of distortion was hardly explained by anthropometric and DXA variables in women (<5%) and men (∼22%). Both anthropometric and DXA measurements accounted for ∼30% and ∼50% of the variability in degree of dissatisfaction among women and men, respectively. Our results suggest a high frequency of body image distortion in Brazilian adult individuals, as well as dissatisfaction with excess weight, especially among women with excess adiposity. The findings indicate that anthropometric measurements explain much of the variability in degree of body image dissatisfaction in men, with no apparent advantage of the use of more refined DXA measurements.

Body composition analysis using dual-energy x-ray absorptiometry in an Egyptian pediatric sickle cell disease cohort.

Growth failure is commonly encountered in sickle cell disease (SCD). Tissue compartment growth and development are subsequently likely to be altered in such patients. We aimed to analyze body composition in an Egyptian pediatric SCD cohort using dual-energy x-ray absorptiometry (DEXA), one of the most comprehensive and noninvasive assessment methods available. Forty children with SCD ≤18years and 40 healthy youngsters age- and gender-matched were enrolled. Patients' demographic, clinical, and laboratory parameters were obtained from their archived files. All patients and controls were subjected to body composition assessment using a MedixDR-Whole Body DEXA System. In SCD patients; weight and height relative to age Z scores were significantly lower (p<.001), total body lean was significantly higher (p=.006), and total body fat percentage was lower, yet the difference was not statistically significant (p=.09). There were no statistically significant variations in bone mineral density or content, basal metabolic rate, subcutaneous adipose tissue, android/gynoid fat ratio, and visceral adipose tissue. There were no significant gender disparities between SCD patients and controls. Faltering growth in children with SCD should be addressed with a multidisciplinary approach including nutritional support, correction of anemia, and proper medical care. Body composition parameters assessed using DEXA were comparable between cases and controls apart from total body lean. Further clinical studies are needed with multicenter cooperation and a larger sample size to assess the usefulness of DEXA as an assessment tool for body composition in children with SCD.

Computed Tomography and Dual-Energy X-Ray Asorptiometry body composition parameter harmonisation to universalise adipose tissue measurements in a population-based cross-sectional study.

To harmonise computed tomography (CT) and dual-energy x-ray absorptiometry (DXA) body composition measurements allowing easy conversion in longitudinal assessments and across cohorts to assess cardiometabolic risk and disease. Retrospective cross-sectional observational study from 1996 to 2008 included participants in the Pennington Center Longitudinal Study (PCLS) (N = 1967; 571 African American/1396 White). Anthropometrics, whole-body DXA and abdominal CT images were obtained. Multi-layer segmentation techniques (Analyze; Rochester, MN) quantified visceral adipose tissue (VAT). Clinical biomarkers were obtained from routine blood samples. Linear models were used to predict CT-VAT from DXA-VAT and examine the effects of traditional biomarkers on cross-sectional-VAT. Predicted CT-VAT was highly associated with measured CT-VAT using ordinary least square linear regression analysis and random forest models (R2 = 0.84; 0.94, respectively, p < .0001). Model stratification effects showed low variability between races and sexes. Overall, associations between measured CT-VAT and DXA-predicted CT-VAT were good (R2 > 0.7) or excellent (R2 > 0.8) and improved for all stratification groups except African American men using random forest models. The clinical effects on measured CT-VAT and DXA-VAT showed no significant clinical difference in the measured adipose tissue areas (mean difference = 0.22 cm2). Random forest modelling seamlessly predicts CT-VAT from measured DXA-VAT to a degree of accuracy that falls within the bounds of universally accepted standard error.

Investigating nutritional status and body composition in children with cerebral palsy; the Eat, Sleep Play-CP study

Cerebral palsy (CP), or to use the Te Reo term “Hōkai Nukurangi”, is an umbrella name for a group of permanent neurodevelopmental disorders, affecting movement and posture(1), and is the most common childhood onset physical disability globally. The available literature on the nutritional status of children with CP describes high rates of malnutrition, however data appears to be skewed towards children of higher levels of impairment impacting functional independence. Less is known about the nutritional status of children with lower levels of impairment. The aim of the “Eat, Sleep, Play-CP” study was to evaluate total energy intake, total protein intake and the timing of protein intake in relation to physical activity for children with CP across all functional levels living in Aotearoa New Zealand. Children with CP aged 5-12 years were invited to participate in an observational assessment of dietary intake using parent reported 24-hour dietary recall (Intake 24) on three non-consecutive days, accompanied by a questionnaire capturing self-reported sleep and physical activity patterns. Body composition was assessed via whole body dual energy X-ray absorptiometry scan. Nine participants (6 males, median age: 10 years, n = 2 Māori), across Gross Motor Function Classification System levels I-IV, and Eating and Drinking Classification System levels I-III took part in the study. The median total energy intake was 7267kJ/d (range 5355-10731.96kJ/d), and median protein intake was 67g/d (range 49-111g/d). According to the Nutrient Reference Values for Australia and New Zealand (NRV)(2), 3 of the 9 participants (33%) were within the recommended range for energy intake according to their age and reported physical activity levels. Of the other 6, 4 were below and 2 were above the recommended ranges. All 9 met the recommended protein intake (NRV). Participants had a median percentage body fat of 40% (range 20-46%), and non-fat mass of 58% (range 52-76%). Five participants fell within the overweight or obese range for their age and sex, three of whom were within the recommended range of total energy daily intake according to NRVs. This outcome may indicate that for some children with CP, recommendations could be over-estimating the actual requirements. These early results may bring in to question current practice around guidance for energy intake requirements for children with CP and their whānau to support healthy body composition. Further investigations are needed to establish whether specific energy intake guidelines are required for children with CP.

Bone Density in Transgender Youth on Gender-Affirming Hormone Therapy.

Some transgender youth are treated with gonadotropin-releasing hormone agonists (GnRHa) followed by testosterone or estradiol, which may impact bone mineral density (BMD). This cross-sectional study of transgender youth (n = 56, aged 10.4-19.8 years, 53% assigned female at birth [AFAB]) utilized total body dual-energy x-ray absorptiometry to evaluate BMD Z-scores, and associations between GnRHa duration, body mass index (BMI), and BMD. Participants on GnRHa alone (n = 19, 14 assigned male at birth [AMAB], 5 AFAB) at the time of the study visit were 13.8 [12.8, 15.3] (median [IQR]) years old, had been on GnRHa for 10 [5.5, 19.5] months, and began GnRHa at age 12 [10.4, 12.6] years. Total body BMD Z-score for individuals on GnRHa monotherapy was -0.10 [-0.8, 0.4] (AFAB, female norms) and -0.65 [-1.4, 0.22] (AMAB, male norms). AFAB participants (n = 21) on testosterone were age 16.7 [15.9, 17.8] years, had been on testosterone for 11 [7.3, 14.5] months, and started testosterone at age 16 [14.8, 16.8] years; total body BMD Z-score -0.2 [-0.5, 0] (male norms) and 0.4 [-0.2, 0.7] (female norms). AMAB participants (n = 16) were age 16.2 [15.1, 17.4] years, had been on estradiol for 11 [5.6, 13.7] months, and started estradiol at age 16 [14.4, 16.7] years; total body BMD Z-score -0.4 [-1.1, 0.3] (male norms) and -0.2 [-0.7, 0.6] (female norms). BMD Z-score was negatively correlated with GnRHa duration (male norms: r = -0.5, P = .005; female norms: r = -0.4, P = .029) and positively correlated with BMI (male norms: r = 0.4, P = .003; female norms: r = 0.4, P = .004). In this cross-sectional cohort, total body BMD Z-scores were slightly below average, but lowest in the AMAB group on GnRHa monotherapy.

Risk of Obesity and Unhealthy Central Adiposity in Adolescents Born Preterm With Very Low Birthweight Compared to Term-Born Peers.

Background: Early-life factors such as preterm birth or very low birthweight (VLBW) are associated with increased cardiovascular disease risk. However, it remains unknown whether this is due to an increased risk of obesity (unhealthy central adiposity) because studies have predominantly defined obesity based on BMI, an imprecise adiposity measure. Objective: Investigate if adolescents born preterm with VLBW have a higher risk of unhealthy central adiposity compared to term-born peers. Study Design: Cross-sectional analysis of data from a prospective cohort study of 177 individuals born preterm with VLBW (<1500 g) and 51 term-born peers (birthweight ≥2500 g). Individuals with congenital anomalies, genetic syndromes, or major health conditions were excluded. Height, weight, waist circumference, skin fold thickness, and dual energy X-ray absorptiometry body composition were measured at age 14 years. We calculated BMI percentiles and defined overweight/obesity as BMI ≥85th percentile for age and sex. We estimated the preterm-term differences in overweight/obesity prevalence and adiposity distribution with multivariable generalized linear models. Results: There was no difference in small for gestational age status or overweight/obesity prevalence. Compared to term, youth born preterm with VLBW had lower BMI z-score [β -0.38, 95% confidence limits (CL) -0.75 to -0.02] but no differences in adiposity apart from subscapular-to-triceps ratio (STR; β 0.18, 95% CL 0.08 to 0.28). Conclusions: Adolescents born preterm with VLBW had smaller body size than their term-born peers and had no differences in central adiposity except greater STR.

Abstract A029: Metabolomic profiles among African-American and White breast cancer survivors: An exploratory comparison of correlations with body weight and body composition

Abstract Objective: Obesity, a strong risk and prognostic factor for postmenopausal breast cancer, is associated with numerous disruptions to the metabolome. However, it remains unclear whether obesity-metabolite associations vary when considering direct measures of adiposity versus body weight, particularly among breast cancer survivors. This analysis aims to compare correlations of body mass index (BMI) and dual-energy x-ray absorptiometry (DXA) derived measures of adiposity (percent fat, total fat) with global serum metabolites. Methods: A cross-sectional analysis was conducted among 60 postmenopausal breast cancer survivors, including 25 African-American and 35 White women within five years of their breast cancer diagnosis who were seen for care at the University of Maryland (UM) Greenebaum Comprehensive Cancer Center (Baltimore, Maryland) and the Cancer Institute at the UM St. Joseph Medical Center (Towson, Maryland). Measured height and weight were used to calculate body mass index (kg/m2); percent fat, total fat and lean mass were quantified using DXA. Global metabolomic profiling in EDTA plasma samples was performed by liquid chromatography-tandem mass spectrometry at Metabolon, Inc. Metabolites were log transformed and partial correlations of BMI, percent fat and total fat (adjusted for age, race and fasting status) were estimated. Analyses of total fat also adjusted for lean mass. The Benjamini Hochberg procedure was used to control the false discovery rate for multiple comparisons. Results: A total of 1353 metabolites, including those with known and unknown identities, were detected. After excluding metabolites with a coefficient of variation ³ 25% or with ³ 30% of values below the limit of detection, 978 metabolites remained for analyses. The median BMI among all women (n=60) was 29.7 kg/m2 ranging from 20.7-46.7 kg/m2. Percent fat ranged from 30.5 – 54.3% with a median of 41.1% while the median total fat was 27.9 kg (17.2-62.7 kg). BMI was strongly correlated with %fat (r=0.8, p=6.6e-08) and total fat after adjustment for lean mass (r=0.6, p=5.7e-05). In analyses of all women, after adjustment for age, race and fasting status, 73 metabolites correlated with BMI, 110 with percent fat and 92 with total fat adjusted for lean mass (q-value &amp;lt;.15). Of those, 27 metabolites correlated with all three metrics while 39 metabolites were distinctly correlated with BMI only, 10 with percent fat only and 21 with total fat only. BMI, percent fat and total fat were most commonly correlated with lipids and amino acids. Conclusions: Preliminary analyses suggest characterizing obesity with metrics of body composition may provide further insight into obesity-metabolite associations among breast cancer survivors. Analyses are ongoing to assess differences in correlations by race and to examine metabolite patterns via metabolite set enrichment analyses. Citation Format: Cher M Dallal, Li Feng, Charles Ma, Katherine Tkaczuk, Stephen Thomas, Joanne F. Dorgan. Metabolomic profiles among African-American and White breast cancer survivors: An exploratory comparison of correlations with body weight and body composition [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr A029.

Effect of exercise-induced body fluid redistribution on body composition in males using dual energy X-ray absorptiometry

ABSTRACT We studied the effect of exercise-induced body fluid redistribution on dual-energy x-ray absorptiometry (DXA) body composition scores. Thirty males completed 30-min of upper-body exercise (UBE), lower-body exercise, and seated non-exercise control (NEC). ANOVA determined interactions between experimental conditions and measurements on body composition variables. For UBE, mean pre to post differences were found on tissue fat (M = 0.35 ± 0.12%; CI95%diff = 0.10 to 0.59%; p = 0.007), region fat (M = 0.32 ± 0.11%; CI95%diff = 0.09 to 0.55%; p = 0.008), lean mass (M = 0.27 ± 0.01 kg; CI95%diff = 0.18 to 0.37 kg; p ≤ 0.0001), and total mass (M = 0.27 ± 0.05 kg; CI95%diff = 0.17 to 0.36 kg; p ≤ 0.0001). Mean tissue pre to post differences were found for the total body in the NEC (M = 0.10 ± 0.04 kg; CI95%diff = 0.03 to 0.18 kg; p = 0.008), UBE (M = 0.19 ± 0.03 kg; CI95%diff = 0.14 to 0.24 kg; p ≤ 0.0001), and LBE (M = 0.31 ± 0.04 kg; CI95%diff = 0.24 to 0.39 kg; p ≤ 0.0001) conditions. High absolute reliability was found within experimental conditions. These findings have practical implications for technicians, since acute exercise elicited small changes in body composition scores using DXA.

Effect of Menstrual Cycle Phase and Hormonal Contraceptives on Resting Metabolic Rate and Body Composition.

The cyclical changes in sex hormones across the menstrual cycle (MC) are associated with various biological changes that may alter resting metabolic rate (RMR) and body composition estimates. Hormonal contraceptive (HC) use must also be considered given their impact on endogenous sex hormone concentrations and synchronous exogenous profiles. The purpose of this study was to determine if RMR and dual-energy X-ray absorptiometry body composition estimates change across the MC and differ compared with HC users. This was accomplished during a 5-week training camp involving naturally cycling athletes (n = 11) and HC users (n = 7 subdermal progestin implant, n = 4 combined monophasic oral contraceptive pill, n = 1 injection) from the National Rugby League Indigenous Women's Academy. MC phase was retrospectively confirmed via serum estradiol and progesterone concentrations and a positive ovulation test. HC users had serum estradiol and progesterone concentrations assessed at the time point of testing. Results were analyzed using general linear mixed model. There was no effect of MC phase on absolute RMR (p = .877), relative RMR (p = .957), or dual-energy X-ray absorptiometry body composition estimates (p > .05). There was no effect of HC use on absolute RMR (p = .069), relative RMR (p = .679), or fat mass estimates (p = .766), but HC users had a greater fat-free mass and lean body mass than naturally cycling athletes (p = .028). Our findings suggest that RMR and dual-energy X-ray absorptiometry body composition estimates do not significantly differ due to changes in sex hormones in a group of athletes, and measurements can be compared between MC phases or with HC usage without variations in sex hormones causing additional noise.

Addressing the Main Barrier to Sarcopenia Identification: Utility of Practical Office-Based Bioimpedance Tools Vs. Dual Energy X-ray Absorptiometry (DXA) Body Composition for Identification of Low Muscle Mass in Older Adults.

Sarcopenia is associated with increased morbidity and mortality. Clinically, sarcopenia can be overlooked, especially in obesity. Sarcopenia diagnostic criteria include muscle mass (MM) and function assessments. Muscle function can be readily assessed in a clinic setting (grip strength, chair stand test). However, MM requires dual-energy X-ray absorptiometry (DXA) Body Composition (BC) or other costly tools, not readily available. Observational cohort pilot study of independently mobile, community dwelling older adults, comparing MM using two office-based, direct-to-consumer bioimpedance (BIA) scales (Ozeri® [manufactured in China] and OMRON® [OMRON HBF-510® Full Body Sensor, Shiokoji Horikawa, Kyoto, Japan] to DXA. The OMRON differs from the Ozeri scale because the OMRON also includes hand sensors. The European Working Group on Sarcopenia in Older People (EWGSOP) DXA or BIA low MM diagnostic cut-offs were used to classify participants as having low or normal MM. Fifty participants: 11 men, 39 women. Forty-two completed DXA. Age 75.8 yrs [67-90]. 81% obese based on body fat cut-offs. With DXA [ASM/height2], 15 had low MM. Using BIA [mmass/height2], 7 with Ozeri, and 27 with OMRON, had low MM. Positive predictive value for low MM versus DXA (as the gold standard) for Ozeri was 73.3% and OMRON was 92.8%. Good correlation between BIA scales and DXA for body fat estimates. OMRON captured all low MM participants identified by DXA plus all on DXA diagnostic borderline. Prevalence of obesity was high. Clinically, sarcopenic obese is the most difficult phenotype, as obesity masks low muscle mass. Low cost, readily available, direct-to-consumer BIA BC scales, especially with hand sensors, provide immediate, reliable information on muscle and fat mass. This can prompt appropriate investigation and/or intervention for sarcopenia or sarcopenic obesity.

Body fat distribution, fat-free mass and cardiovascular function in the UK Biobank

Abstract Background Excess adiposity and high body mass index have been associated with cardiac dysfunction and heart failure. However, the role of whole body imaging and independent associations of regional fat and fat-free mass on left ventricular and vascular function is unclear. Purpose This study determined the cross-sectional associations of regional fat depots and fat-free mass on left ventricular function and arterial stiffness to explain obesity-related cardiac dysfunction. Methods Participants who underwent whole body magnetic resonance imaging (MRI) and dual energy X-ray absorptiometry (DXA) in an ongoing imaging study of 100,000 individuals in the UK were included in this analysis. Analyses exclude individuals with major cardiac and vascular diseases at initial baseline assessment. Regional fat distribution was quantified using MRI while body fat-free mass was quantified with DXA. Cardiac MRI was used to measure left ventricular (LV) ejection fraction and LV mass while pulse wave velocity from finger photo-plethysmography was used to measure arterial stiffness index. Associations of body fat distribution (visceral fat, abdominal subcutaneous fat, other body fat) and fat-free mass with each of LV ejection fraction, LV mass and arterial stiffness index, after mutual adjustment for one another and potential confounders were determined using multivariable linear regression. Results We included 31,088 individuals (mean age 63.4 years, 53% women). Among regional body fat measures, higher visceral fat was associated with lower LVEF (β=-0.43; 95% CI: -0.55, -0.31 per SD) and higher arterial stiffness index (β=0.44; 95% CI: 0.34, 0.54 per SD) while none of the regional fat and fat-free mass showed significant association with LV function or arterial stiffness. None of the fat or fat-free mass measures showed significant association with LV mass. These associations were not explained by inflammatory markers, blood pressure or glycaemic profile. Conclusion Visceral fat is the main driver of obesity-related cardiac and vascular dysfunction. There is need for further studies to understand the biological causal pathways of obesity-heart disease.Figure 1Figure 2

Discovering the Individualized Factors Associated with Sarcopenia and Sarcopenic Obesity Phenotypes-A Machine Learning Approach.

The literature shows how sarcopenia often occurs along with different phenotypes based either on the concomitant presence of adipose tissue excess (i.e., sarcopenic obesity, SO), or osteopenia/osteoporosis (osteosarcopenia, OS), or the combination of the two conditions, so-called osteosarcopenic obesity (OSO). This research aimed to assess the prevalence of sarcopenia phenotypes (SO, OS, OSO), their associated risk factors and their health impact in a population of out- and inpatients living in the North of Italy. Male and female subjects aged ≥18 years were enrolled for the study. A blood sample was collected to measure targeted blood makers. A comprehensive anthropometric clinical assessment (height, weight, Body Mass Index, BMI and Dual Energy X-ray Absorptiometry, DXA) was performed to measure ponderal, bone, fat, and muscle status. A total of 1510 individuals participated to the study (females, n = 1100; 72.85%). Sarcopenia was the most prevalent phenotype (17%), followed by osteosarcopenia (14.7%) and sarcopenic obesity. Only 1.9% of the sample was affected by OSO. According to logistic regression analysis, sarcopenia was associated with age, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) (positively) and BMI, Iron (Fe), Total Cholesterol, albumin (%), albumin (g), and gamma proteins (negatively). Sarcopenic obesity was associated with age, ferritin, ESR, CRP (positively) and BMI, Fe, and albumin (%) (negatively). Osteosarcopenia was associated with age, ESR (positively) and BMI, Total Cholesterol, albumin (%), albumin (g), and Ca (negatively). Osteosarcopenic obesity was associated with glycemia and gamma-glutamyl transferase (gGT) (positively). According to random forest analysis, a higher BMI was the most important protective factor for sarcopenia, for sarcopenic obesity (along with Iron) and for osteosarcopenia (along with albumin). Moreover, osteosarcopenic obesity was positively associated with GgT and glycaemia. The possibility of gaining such information, especially in the younger population, could help to prevent the onset of such diseases and best fit the patient's needs, according to a precision-medicine approach.

Effect of six weeks of resistance training on bone preservation in older adults: a randomized control trial.

It has been established that chronic resistance exercise contributes to positive changes to bone in older adults. This study evaluated the effect of 6weeks of resistance exercise with either elastic bands or dumbbells vs. a control period on bone morphology of older adults. Fifty-seven adults (mean ± SD; age = 66.5 ± 7.09 yrs; height = 165.2 ± 10.6cm; body mass = 74.5 ± 14.6kg) were randomized into three groups (dumbbell, elastic, or control). Participants underwent a total body dual-energy X-ray absorptiometry (DXA) scan for total body and segmental bone mineral content (BMC) and bone mineral density (BMD) before and following 6-week intervention. Age-matched Z-scores for BMD and BMC were recorded. Data were analyzed using two-way repeated measures ANOVAs and 0.05 significance level. BMCarm improved for the dumbbell group (p = 0.016) after the training, with no change in BMD for any group (p > 0.05). Additionally, significant (time x treatment group) interaction (p = 0.024) of age-matched Z-scores indicated an improvement in only the dumbbell group after 6weeks (p = 0.015), with no change in the elastic group despite them having greater Z-scores than the control group. This study is the first to demonstrate acute normative adaptations as dumbbell-based programs may promote positive maintenance of bone metrics over 6weeks, despite the lack of significant change in absolute BMC or BMD. Adults did not lose relative bone mass with acute exercise using dumbbells as the external load applied and this may lead to positive changes following chronic training. There was no bone-related impact from elastic bands, suggesting a weighted load or force produced relative to gravity is beneficial.