Total Body Fat Percentage Research Articles

Geographical Effects In Familial Clustering Of Physical Activity, Adiposity And Metabolic Syndrome

Metabolic syndrome (MetS) risk factors, adiposity and physical activity (PA) levels have a multifactorial aetiology, comprising genetic and non-genetic factors. Notwithstanding the consistent findings about their aetiology, biological and behavioural traits do not explain the total variation and the increase of metabolic disorders and physical inactivity over the past decade. Additionally, links may be identified between built and natural environments, namely PA environments, on adiposity, MetS and PA phenotypes, as well as how they may affect different behaviours, especially within families. PURPOSE: The purpose of this study was to estimate the magnitude of genetic and environmental factors on adiposity, MetS risk factors and PA levels, and to investigate the role of PA environments on these traits. METHODS: The sample comprised 259 nuclear families (781 individuals) from a rural city of Portugal. All PA facilities’ locations and families’ home addresses were geocoded and Euclidian distances were calculated. Percentage of total body fat was estimated by bioelectrical impedance. Systolic and diastolic blood pressure, waist circumference, fasting glucose, triglycerides and total cholesterol were measured. PA was estimated by the Baecke questionnaire. Quantitative genetic models were used and computations performed in SOLAR software. RESULTS: Genetic and shared environmental factors explained 22% and 38% of PA and body fat total variance, respectively. MetS risk factors were moderate-to-highly heritable, ranging from 26% to 73%. Spatially structured data of PA environments had significant effects on MetS risk factors, adiposity and PA phenotypes (p<0.05), except for waist circumference, contributing to low adiposity levels (p<0.05), increases in PA (p<0.05), and being protective against the development of MetS risk factors (p<0.05). CONCLUSIONS: Taken together, these results have important implications for the design of intervention programs, which need to consider the familial context and PA environments to promote physically active lifestyles and their positive effects on health.

24-hour Movement Behaviors, Body Composition And Cognitive Performance In Adolescents

PURPOSE: The purpose of this pilot study was to examine associations between 24-hour movement behaviors (sleep, physical activity, and sedentary time), body composition, and executive functions in adolescents with and without obesity. METHODS: Adolescents between the ages of 12 and 18 years (n=30, n=14 girls, mean age=14.9 years) wore accelerometers on the hip for 24-hours to measure total night sleep time, minutes of moderate-to-vigorous physical activity (MVPA), and percentage of waking wear in sedentary activity. Body composition including lean mass, fat mass and bone mineral density was measured using dual-energy x-ray absorptiometry. Cognitive performance, particularly attention and inhibitory control, was tested using the Go/NoGo task. RESULTS: Mean sleep time was 487.2 (SD 80.0) minutes per night, median minutes of moderate-to-vigorous physical activity were 16 (10.2, 25.3 25th to 75th percentiles) minutes per day, and 68.5% (SD 6.95) of waking time was spent in sedentary activity. There were no differences in sleep or sedentary time in adolescents with and without obesity, however, adolescents with obesity participated in less MVPA compared to those without obesity (median 13.4 vs 23.3 minutes per day respectively, p=.024). In linear regression models with all three behaviours as independent variables adjusted for total body mass, sex, and age, total sleep time (minutes/day), but not sleep efficiency, was positively associated with total body percent fat (0.05, 95%CI: 0.002, 0.11, p=.043) and negatively associated with total lean mass (-37.8 grams, 95%CI: -71.7, -4.0, p=.030). Using negative binomial regression adjusted for age and sex, there were no associations of any of the movement behaviors with accuracy (errors of omission or commission) or reaction times. Body fat percentage (IRR 1.06, 95%CI: 1.01, 1.12), p=.026) and total lean mass (kg) (IRR 0.89, 95%CI, 0.80, 0.97, p=.013) were associated with omission errors of inattention. CONCLUSION: In this sample of adolescents, total sleep time was associated with body fat and lean mass. Body composition was associated with inattention. Novel interventions that integrate sleep strategies to improve health and cognitive performance in adolescents should be explored.

Oxygen Desaturation in Sleep Apnea is Inversely Associated with Vascular Changes Following Exercise Training

PURPOSE: Obstructive sleep apnea (OSA) is characterized by reductions in nocturnal mean O2 saturation (meanSpO2) that may increase cardiovascular disease morbidity. The extent to which exercise confers cardioprotection in overweight adults with different meanSpO2 profiles is not known. The purpose of this study was to examine the association of meanSpO2 with vascular function changes following exercise training in adults with and without OSA. METHODS: At baseline, participants underwent overnight polysomnography to determine the presence and severity of OSA. Tertile-based cut-off points were used to categorize meanSpO2 and apnea hypopnea index (AHI). Body fat was analyzed using dual energy X-ray absorptiometry. Vasoreactivity of the brachial artery was measured using flow-mediated dilation (FMD), while microcirculatory function was assessed via the total shear stress area under the curve (SSAUC) response during FMD. Body fat and vascular measures were repeated upon completion of a 6 week (3 sessions/wk; 1 hr/session) exercise training program. RESULTS: Thirty (age: 49+9 years; BMI: 32.0+3.8 kg/m2; 18 men: 12 women) adults with and without OSA completed the study. At baseline, adults in the highest tertile of meanSpO2 were younger than those in the lowest tertile (43+9 yrs vs. 53+7 yrs, p=0.017), yet no differences in vascular measures, AHI or total body fat percentage were observed across the tertiles. No changes in brachial artery diameter or FMD were observed across tertiles following exercise. However, the change in SSAUC in the highest tertile of meanSpO2 was greater, compared to the lowest tertile (13,636+15898 A.U. vs. -186+10879 A.U., p=0.041). Forward stepwise linear regression revealed that the highest tertile of meanSpO2 was a significant (F=5.15, p=0.036) determinant of the increased SSAUC with exercise, independent of age and baseline SSAUC. CONCLUSIONS: Severe oxygen desaturation during sleep was inversely associated with improvements in microcirculatory function following exercise training.

The Prevalence of Body Composition Criterion Methods for Validation Studies in Humans

PURPOSE: To determine the recent prevalence of body composition criterion methods in validation studies of total body percent fat or fat free mass. METHODS: A literature search was performed to identify studies between 2013 - 2018 using the following key words: four component model, validation, body composition, and fat using Medline. Only human studies published in English were included. One person (L. Milliken) screened all articles and coded the results to identify the criterion and comparison methods used. For all studies where multi component models were used, a further note was made regarding what methods comprised those models. All methods were summarized to capture the prevalence of methods used in the literature for body composition validation studies. RESULTS: A total of 176 articles were identified; 128 measured total body composition or body volume articles and were included. Some studies used more than one criterion method. 10.9% of studies used a 2 component (2C) model, 67.2% used a 3C model and 10.9% used a 4C model as a criterion method. The most common 2C, 3C, and 4C models respectively were air displacement plethysmography (ADP)(9.3%), dual-energy x-ray absorptiometry (DXA) (62.5%) and ADP/DXA/total body water (TBW) (7.8%). 3.9% of studies used an inappropriate 3C or 4C model by using bioimpedance spectroscopy (BIS) in place of TBW by isotope dilution. The criterion methods used in order of prevalence were DXA (62.5%), 4C (10.9%), ADP (9.4%), isotope dilution (7.0%), magnetic resonance imaging (4.7%), 3C not including DXA (4.7%), bioelectrical impedance analysis (3.9%), and underwater weighing (1.6%). CONCLUSIONS: Body composition validation studies are dominated by DXA as a criterion method which may not be appropriate in all situations. Also, researchers are incorrectly using field methods rather than laboratory methods (most commonly using BIS for TBW) as part of the 4C model in validation studies. The gold standard for body composition validation studies remains the 4C model with TBW determined by isotope dilution.

320-LB: Metabolically Unhealthy Overweight Individuals Have High Lysophosphatide Levels, Phospholipase Activity, and Oxidative Stress

Background and Aims: Metabolically unhealthy overweight (MUO) individuals and metabolically healthy overweight (MHO) individuals differ in biomarkers of atherogenesis. Metabolomic approaches enable studies of the metabolic variables underlying these differences. Methods: We determined the metabolomes in plasma samples from 34 MUO and 34 MHO individuals matched for sex, age, and body mass index (BMI) to identify potential metabolic markers or pathways associated with atherogenic traits. Results: This analysis revealed that the MUO group had significantly higher levels of glycolic acid, 6 lysophosphatidylethanolamines (lysoPEs), and 12 lysophosphatidylcholines (lysoPCs). Although the two groups had similar total body fat percentages and lean body masses, MUO individuals had larger visceral fat areas (VFAs). They also had greater circulating lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and higher levels of oxidized low-density lipoprotein (ox-LDL) and urinary 8-epi-prostaglandin F2α (8-epi-PGF2α), reflecting higher risks for oxidative and lipid-related tissue damage. The following measures were positively correlated: VFA and ox-LDL; ox-LDL and Lp-PLA2 activity; and lysoPC, lysoPE, and 8-epi-PGF2α levels. Chronic plasma lysoPC increases were associated with atherogenic traits, higher levels of mean ox-LDL, 8-epi-PGF2α, Lp-PLA2, and visceral fat accumulation in MUO compared to MHO individuals. Conclusions: This panel of plasma metabolites distinguishes MUO from MHO individuals and will enable future research on fat dysregulation and obesity. Disclosure Y. Han: None. M. Kim: None. H. Yoo: None. J. Lee: None. Funding National Research Foundation of Korea (NRF-2017R1C1B2007195, NRF-2012M3A9C4048762)

Feasibility and Effectiveness of Community-Based Virtual Reality Group Exercise Training in Persons with Spinal Cord Injury

Persons with spinal cord injury (SCI) are at an increased risk of physiological morbidity compared to their ambulatory counterparts in whom well-established, beneficial correlations exist between exercise, cardiorespiratory health and body composition. Furthermore, SCI who participate in sport may have reduced risk of physiological morbidity than SCI who are sedentary. PURPOSE: This pilot study was two-fold: 1) to determine whether differences exist in cardiorespiratory health and body composition between SCI athletes (ATHL) and sedentary SCI (SED), and 2) to determine whether an 8-week handcycle exercise training program is feasible in an SED SCI population, and if improvements in cardiorespiratory fitness and body composition occur. METHODS: Twenty-seven SED and six ATHL were recruited to participate in the study. All SCI completed a graded hand cycling maximal exercise test for cardiorespiratory fitness (VO2max) and body composition testing (iDEXA). SED participants were then randomized into a virtual reality intervention (VR) or waitlist (WL) group (e.g. offered VR after 8 weeks of WL). The intervention consisted of an 8-week community-based VR group hand cycling exercise training with a USA level 1 coach two days/week. Pre-post outcomes were measured in each group. RESULTS: Thirty-three SCI were recruited to participate (SED n=27; ATHL n=6). All ATHL and 17 SED participants (VR=9, WL=8) completed study protocol, with 10 (VR=1 and WL=9) lost to follow up. One participant was dropped from analysis due to not giving a full effort during testing as determined by investigators. ATHL had 23 physiological and anthropometric variables that were significantly different (p≤0.01) compared to SED including higher VO2max (19.1 ml/kg/min), lower BMI (-4.6 kg/m2), and lower total body fat percentage (-10.4%). VO2max increased 16% in VR and 9% in WL, which was not statistically different. CONCLUSION: This study demonstrates the feasibility of a hand cycling program in SCI. ATHL had better outcomes associated with long term health compared to their SED counterparts. Though no significant changes were noted in VR compared to WL, changes in VO2max may be clinically relevant. A larger sample size or longer training period may be needed to observe significant differences in physiological health in an SED SCI population.

Comparison of Total Body Composition and Bone Mineral Density Measures in Female Collegiate Athletes

Body composition and bone mineral density (BMD) are important factors in sport performance and the overall short and long-term health of athletes. Despite this function, few investigations to date have documented total body composition in female collegiate athletes. Further, we are unaware of any studies examining both total body composition and BMD in this population. PURPOSE: To generate descriptive data for total body composition and BMD in a large sample of female collegiate athletes using dual X-ray absorptiometry (DXA) and examine differences between 10 competitive sports. METHODS: A total of 211 female collegiate athletes (19±1yrs; 167.8±8.9cm; 45.9±6.1kg; 2.4% Asian, 15.2% Black, 1.4% Hispanic, 80.6% White, 0.5% Other) underwent DXA: basketball (BB; n=22), cross country (CC; n=11), field hockey (FH; n=25), gymnastics (GYM; n=23), lacrosse (LAX; n=42), soccer (SOC; n=27), swimming; (SW; n=27), tennis; (TN; n=11), track (field only); (TR; n=7), and volleyball; (VB; n=16). Descriptive statistics were calculated for total body fat percentage (BF%), and BMD. Differences in total BF% and BMD between sports were examined using a one-way Welch’s ANOVA test. Post-hoc testing was completed using the Games-Howell test. RESULTS: The mean total BF% was 27.8±5.1% (range: 23.0 - 37.5%) while BMD was 1.30±0.11g/cm2 (range: 1.17 - 1.45g/cm2); TR had the highest BF% (37.5±5.5%), followed by TN (31.1±4.0%) and LAX (29.3±3.8%), CC (23.0±6.0%) and GYM (23.5±2.9%) had the lowest. For BMD, TR had the highest (1.45±0.07g/cm2), followed by BB (1.40±0.12g/cm2) and VB (1.36±0.10g/cm2); CC (1.17±0.07g/cm2) and SW (1.22±0.06 g/cm2) had the lowest. Group mean differences in BF% (p<0.001; ω2 = 0.26) and BMD (p<0.001; ω2 = 0.35) were observed between teams. Specifically, GYM had lower BF% than BB, FH, LAX, SOC, SW, TN, and TR (mean difference range: -4.0 to -13.9%, all p<0.05). CC had lower BMD than BB, FH, GYM, LAX, SOC, TR, and FH (mean difference range: -0.11 to -0.28g/cm2, all p<0.01). CONCLUSION: Total body composition and BMD measures varied across female collegiate sports. These findings may assist sports medicine and strength and conditioning practitioners with identifying appropriate goal values for BF% and BMD in female collegiate athletes across various sports.

Cardiorespiratory fitness predicts cardiovascular health in breast cancer survivors, independent of body composition, age and time post-treatment completion

Breast cancer treatment may increase non-cancer related mortality risk due to unintended cardiovascular consequences. The aim of this study was to investigate the strongest correlate of cardiovascular health (CVH) in female breast cancer survivors, cardiorespiratory fitness or fatness. Fifty-one women (59 ± 9years, BMI 26.4 ± 4.8kg/m2) previously diagnosed and treated for primary breast cancer were assessed using pulse wave analysis to determine central arterial wave reflection (augmentation index, AIx) and central systolic blood pressure (cSBP). A composite Z score calculated which incorporated central double product and AIx, as an indicator of CVH. Dual energy X-ray absorptiometry was used to obtain total body fat percentage (BF%). Cardiorespiratory fitness was determined using the single-stage walk test to predict maximal oxygen uptake ([Formula: see text]). Linear regression analysis revealed that fitness was associated with AIx after adjusting for BF%, age and time post-treatment completion (β = -0.271, p = 0.010). A significant association between BF% and AIx after adjusting for fitness and age was found (β = 0.166, p = 0.0005); however, this association was lost when time post-treatment was included in the model (β = 0.166, p = 0.167). Both fitness (β = -0.347, p = 0.0005) and BF% (β = 0.333, p = 0.013) were independently associated with CVH in the fully adjusted model. This study provides evidence for an association between cardiorespiratory fitness and cardiovascular health in female breast cancer survivors. While fatness may be associated with cardiovascular health, it appears to be more strongly associated with age.

IMPACT OF BODY FAT AND OBESITY ON TISSUE DIELECTRIC CONSTANT (TDC) AS A METHOD TO ASSESS BREAST CANCER TREATMENT-RELATED LYMPHEDEMA (BCRL)

Obesity is linked to the risk of breast cancer and treatment-related lymphedema (BCRL). Thus, knowledge of how obesity, or more specifically total body fat percentage (TBF) and body mass index (BMI), affect measurements that are used to detect or track lymphedema is clinically important. Tissue dielectric constant (TDC) is one measure used to help characterize lymphedema features, detect its presence, and assess treatment-related changes. The goal of this research was to determine the extent to which TDC values depend on TBF and BMI. TDC was measured on both forearms (2.5mm depth) in 250 women (18-72 years) along with TBF (impedance, 50KHz). TBF was 12.2%- 54.4% (median=29.3%) and BMI was 14.7Kg/m2-44.3 Kg/m2 (median=22.6 Kg/m2). TDC values and interarm ratios were compared between subgroups that had TBF and BMI values in lower vs. upper quartiles. Subjects in the upper quartile had slightly lower TDC values (1.3 TDC units, p <0.01) that was at most a 5% differential. Contrastingly, TDC interarm ratios were not dependent on TBF or BMI levels. These findings suggest that when tracking lymphedema changes using the TDC method, treatment-related or temporal changes in a woman's TBF or BMI are unlikely to significantly impact TDC values or their interarm ratios.

Metabolically unhealthy overweight individuals have high lysophosphatide levels, phospholipase activity, and oxidative stress

Metabolically unhealthy overweight (MUO) individuals and metabolically healthy overweight (MHO) individuals differ in biomarkers of atherogenesis. Metabolomic approaches enable studies of the metabolic variables underlying these differences. We determined the metabolomes in plasma samples from 34 MUO and 34 MHO individuals matched for sex, age, and body mass index (BMI) to identify potential metabolic markers or pathways associated with atherogenic traits. This analysis revealed that the MUO group had significantly higher levels of glycolic acid, 6 lysophosphatidylethanolamines (lysoPEs), and 12 lysophosphatidylcholines (lysoPCs). Although the two groups had similar total body fat percentages and lean body masses, MUO individuals had larger visceral fat areas (VFAs). They also had greater circulating lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and higher levels of oxidized low-density lipoprotein (ox-LDL) and urinary 8-epi-prostaglandin F2α (8-epi-PGF2α), reflecting higher risks for oxidative and lipid-related tissue damage. The following measures were positively correlated: VFA and ox-LDL; ox-LDL and Lp-PLA2 activity; and lysoPC, lysoPE, and 8-epi-PGF2α levels. Chronic plasma lysoPC increases were associated with atherogenic traits, higher levels of mean ox-LDL, 8-epi-PGF2α, Lp-PLA2, and visceral fat accumulation in MUO compared to MHO individuals. This panel of plasma metabolites distinguishes MUO from MHO individuals and will enable future research on fat dysregulation and obesity.

Obesity, Brain Volume, and White Matter Microstructure at MRI: A Cross-sectional UK Biobank Study.

Background Obesity has been associated with increased risk of accelerated cognitive decline and dementia, which suggests underlying neurobiological changes. Purpose To investigate the associations between obesity and brain structure (overall and regional brain volumes, and white matter microstructure) assessed at MRI in a sample of the general population. Materials and Methods Between March 2014 and January 2018, 12 087 participants (52.8% women [6381 of 12 087]; mean age, 62 years; age range, 45-76 years) in the prospective observational UK Biobank study underwent 3.0-T multiparametric (ie, three-dimensional T1-weighted diffusion tensor imaging [DTI]) brain imaging. Percentage of total body fat (TBF) was assessed by body impedance. Volumetric measures included brain volume, gray matter volume, white matter volume, volumes of subcortical gray matter structures, and regional cortical volumes. Global and tract-specific microstructure was assessed by fractional anisotropy (FA) and mean diffusivity (MD) by using DTI. Linear regression was performed by using TBF as determinant and brain measures as outcome variables, and effect estimates were expressed as standardized β values. Results Mean body mass index was 26.6 kg/m2 ± 4.4 (standard deviation [SD]), mean TBF in men was 24.4% ± 5.5, and mean TBF in women was 35.5% ± 6.5. In men, TBF was negatively associated with all subcortical gray matter volumes (thalamus, caudate nucleus, putamen, globus pallidus, hippocampus, and nucleus accumbens) other than amygdala volume. In women, TBF was solely negatively associated with globus pallidus volume. In women and men, TBF was positively associated with global FA (women vs men, 0.05 vs 0.07 SD change in global FA per SD change in TBF; P < .001). TBF was negatively associated with global MD in women (-0.07 SD change in global MD per SD change in TBF; P < .001). Conclusion These findings provide evidence that obesity is associated with smaller subcortical gray matter volumes. In addition, obesity was associated with higher coherence but lower magnitude of white matter microstructure, which suggests differential influences of obesity on the geometric organization of white matter microstructure. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Caspers in this issue.

Body Fat Percentage, Waist Circumference, and Obesity As Risk Factors for Rheumatoid Arthritis: A Danish Cohort Study.

To investigate the relationship between bioimpedance-derived total body fat percentage, waist circumference, and body mass index (BMI) and the subsequent development of rheumatoid arthritis (RA). A population-based prospective cohort study was conducted using 55,037 patients enrolled in the Danish Diet, Cancer, and Health cohort. Baseline data included anthropometric measures and lifestyle factors. Individuals who developed RA were identified through linkage with the Danish National Patient Registry. The relationships between bioimpedance-derived body fat percentage, waist circumference, and BMI and incident RA were assessed using Cox proportional hazards regression models, stratifying by sex. All analyses were performed for overall RA and the serologic subtypes seropositive and other RA. A total of 210 men (37.6% with seropositive RA) and 456 women (41.0% with seropositive RA) developed RA during a median follow-up of 20.1 years. In women, the overall RA risk was 10% higher for each 5% increment of total body fat (hazard ratio [HR] 1.10 [95% confidence interval (95% CI) 1.02-1.18]), 5% higher for each 5-cm increment of waist circumference (HR 1.05 [95% CI 1.01-1.10]), and nearly 50% higher in those whose BMI was in the obese range compared to normal range BMI (HR 1.46 [95% CI 1.12-1.90]). These positive associations were also found for patients with other RA. In men, there were no clear associations between body fat percentage, waist circumference, or BMI and RA. No significant associations were found for seropositive RA in women or men, possibly related to low sample size. In women, higher body fat percentage, higher waist circumference, and obesity were associated with a higher risk of RA.

SUN-147 Sarcopenia Is Associated with the Degree of Insulin Resistance and Risk of Type 2 Diabetes in Older Age Group

The aim of this study was to determine an appropriate index for age-related sarcopenia and sarcopenic obesity (SO) and investigate relationships among sarcopenia, insulin resistance and risk of type 2 diabetes. Our analyses included 1285 men and 1724 women who had complete data available for body composition analysis and the 75 g oral glucose tolerance test. A whole-body DXA scan was performed for each patient to measure the total and regional lean mass (kg), the total body fat (kg), and the total body fat percentage (%). The appendicular skeletal muscle mass ASM (kg) was defined as the sum of the lean mass of the arms and legs. Sarcopenia was assessed by the ASM/height2, or the ASM/weight (%). Obesity was identified based on the total body fat percentage or the BMI. The mean ages of men and women were 62.8 ± 8.4 years and 63.3 ± 8.6 years, respectively. As measured using the ASM/Ht2, the cut-off values for sarcopenia were 6.61 kg/m2 in men and 4.25 kg/m2 in women. For the ASM/Wt %, the cut-offs were 30.1% in men and 23.4% in women. ASM/weight, but not ASM/height2, was inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR). The prevalence of sarcopenia and SO, defined as ASM/weight less than the one standard deviation below the sex-specific normal mean of a younger reference group and a BMI of over 25 kg/m2, tended to be higher with increased HOMA-IR tertile. Compared to either sarcopenia or obesity alone, SO was associated with a higher risk of developing type 2 diabetes (P < 0.001, OR = 4.23, 95% CI = 2.08-8.99) in those 60 years or older after adjusting for confounding factors. Subjects with sarcopenia were at especially high risk of newly diagnosed diabetes in older age groups (P < 0.001, OR = 2.92, 95% CI = 1.21-7.02). Sarcopenia and SO, assessed by the ASM/weight and BMI, were strongly associated with the degree of insulin resistance and the risk of developing type 2 diabetes in older adults.

MON-242 Early Breast Development in Overweight Girls: Does Estrogen Made by Adipose Tissue Play a Role?

Overweight/obese girls (OB) undergo thelarche but not menarche significantly earlier than normal weight girls (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that in OB, adipose tissue overlying the breast bud may be a ready source of estrogen that is sufficient to initiate thelarche because the primitive breast bud is intimately associated with the mammary fat pad during development (Anbazhagan Am J Anat ’91, Neville J Mammary Gland Biol Neoplasia ’98). Estrogen derived from mammary fat could act locally to induce thelarche but would not be detected in the circulation and therefore would not act systemically to induce uterine maturation/menses. To address this hypothesis, we measured reproductive hormones and imaged the breast, uterus, and ovaries in 80 pubertal, pre-menarchal girls (26 OB, 54 NW) aged 8.2-14.7 yrs. We used total percent body fat (%BF), determined by DXA, as a proxy for mammary fat, taking advantage of the positive correlation between these two measures (Novotny Am J Hum Biol ’11, Schautz Eur J Clin Nutr ’11, Zhu Eur Radiol ’16). We predicted that if estrogen derived from mammary fat contributes to breast maturation, then girls with higher %BF (and thus more mammary fat) would demonstrate immaturity of other estrogen-sensitive tissues (e.g. uterus, endometrial lining, vaginal epithelium) compared with girls of the same breast morphological stage (stages A-E based on Bruni et al. Adolesc Pediatr Gynecol ‘90) with lower %BF. OB were younger than NW (10.1 ± 1.1 vs. 11.3 ± 1.3 yrs, p<0.001) and more likely to be non-Hispanic Black or Hispanic (p=0.03). %BF ranged from 13.1-53.5% (3rd-97th percentiles). The distribution of Tanner breast and pubic hair stages was similar in NW and OB, and the full spectrum of breast development (A-E) was observed with stages D and E being the most common (59%) overall. Uterine volume, endometrial thickness, sex steroids (E1, E2, T, A’dione), and gonadotropins increased (p<0.001 for all), as expected, with breast morphological stage but %BF was not associated with any index of systemic estrogen action or reproductive hormones in a linear regression model controlled for breast morphological stage. These studies suggest that neither total %BF nor local (mammary) are clinically significant sources of estrogen capable of inducing breast development in OB. Taken together with the comparable gonadotropin levels observed in girls of the same breast morphological stage across a broad range of total %BF, these findings point to earlier activation of the hypothalamic-pituitary-ovarian axis in OB as the most likely cause of earlier thelarche in OB compared with NW. Longitudinal follow-up of this cohort is underway to investigate the effect of %BF on the maturational trajectory of the central components of the female reproductive axis.

CONCURRENT TRAINING AND TAURINE IMPROVE LIPID PROFILE IN POSTMENOPAUSAL WOMEN

ABSTRACT Introduction: Taurine plays an important role in metabolism and can positively influence body composition, since it is believed that in appropriate concentrations this amino acid (AA) can reduce perceived exertion, thereby delaying the onset of fatigue; however, the effect of this AA combined with concurrent training in postmenopausal women is unknown. Objective: To analyze the effects of concurrent training (aerobic+resistance) and taurine supplementation on the metabolic profile of postmenopausal women. Methods: Forty-three postmenopausal women were randomly divided into the following groups: Control (C [N=13]), Taurine (T [N = 8]), Taurine+Exercise (TE [N=13]), and Placebo+Exercise (E [N=9]). The supplemented groups received capsules corresponding to a daily taurine intake of 1.5 g. Concurrent training (CT) took place three times a week and consisted of 50 minutes of resistance training and 30 minutes of aerobic training. Body composition was assessed using DXA, in addition to biochemical profile analysis: triglycerides, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. The intervention period lasted for eight weeks. Statistical significance was set at 5%. Results: The TE group presented a statistical reduction in terms of relative change in the percentage of total body fat (%) (−4.1±3.0) and trunk fat (%) (−4.4±3.9), with greater lean body mass (kg) gain (3.9±2.5) when compared to groups C (0.3±3.7, p=0.005; 0.8±4.3, p=0.024; −1.1±3.1, p&lt;0.001; respectively) and T (1.2±3.4, p=0.004; 1.6±5.4, p=0.023; −1.2±2.9; p=0.002; respectively). The TE group presented a greater percentage reduction of total cholesterol (−5.8±7.1 mg/dl) when compared to group T (11.5±19.1 mg/dl). The TE group presented a significant decrease in LDL-c (−13.6±9.2 mg/dl) compared to groups C (3.5±13.9 mg/dl, p=0.014) and T (9.9±24.3 mg/dl, p=0.027). Conclusion: The combination of concurrent training and taurine supplementation promoted a reduction in total cholesterol and LDL-c levels in postmenopausal women. Level of Evidence I; Study type: Randomized clinical study.

Protocol for the Gut Bugs Trial: a randomised double-blind placebo-controlled trial of gut microbiome transfer for the treatment of obesity in adolescents

IntroductionAnimal studies showed that germ-free mice inoculated with normal mouse gut bacteria developed obesity, insulin resistance and higher triglyceride levels, despite similar food intake. In humans, an association has been...

Association between Habitual Coffee Consumption and Indices of Body Fat

BackgroundDespite strenuous public health efforts, obesity rates continue to rise globally, and contribute importantly to increased cardiometabolic morbidity and mortality. Dietary habits play a key role in the development and progression of obesity, and are the target of choice in preventative and therapeutic programs. Although preclinical studies have shown that caffeine may exert anti‐adipogenic effects, in humans the implications of coffee consumption on risks of excess adiposity are unclear.ObjectiveThe objective of this study was to investigate the association between habitual coffee consumption and indices of total and regional body fat in healthy adults.MethodsSeventy‐eight subjects (46 males, mean age 27.3±6.1 years) who took part in research studies conducted at the Mayo Clinic Cardiovascular/Sleep Laboratory and underwent body composition assessment were selected. Absence of cardiovascular or metabolic diseases was ascertained by physical exam and review of medical charts. Height, weight, waist and hip circumference measures were collected for computation of body mass index (BMI, kg/m2) and waist‐to‐hip ratio (WHR). Measurements of total body fat percentage, upper body fat (kg), and lower body fat (kg) were obtained from dual‐energy X‐ray absorptiometry (DXA). Abdominal computed tomography (CT) was used to quantify subcutaneous adipose tissue (SAT, cm2) and visceral adipose tissue (VAT, cm2). Habitual coffee consumption (cups/day; range 0–3) was self‐reported and coded as a binary variable (yes/no).ResultsSixty percent of the subjects (n=47) reported habitual coffee consumption. Age and gender distribution were comparable between groups (P=0.52 and P=0.73, respectively). There was no significant difference between those who reported consuming coffee and those who did not in terms of BMI (23.6±2.7 kg/m2 vs 24±2.8 kg/m2, P=0.56) and WHR (0.85±0.08 vs 0.85±0.07, P=0.7). Likewise, body composition and fat distribution indices were similar between groups: total body fat percentage (coffee drinkers vs non‐coffee drinkers: 30.5±7.2% vs 28.6±7.8%, P=0.27), upper body fat mass (6.6±2.4 kg vs 6.6±3.1 kg, P=0.99), lower body fat mass (9.4±5.2 kg vs 8.4±4.1 kg, P=0.39), SAT (143.4±61.3 cm2 vs 135.9±63.7 cm2, P=0.6), and VAT (57.7±35.5 cm2 vs 70.3±44 cm2, P=0.22). Analysis stratified by gender did not reveal any differential effect of regular coffee consumption on body fat (all Ps&gt;0.26).ConclusionIn healthy, young individuals moderate habitual coffee consumption is not associated with measures of total or regional adiposity. Whether the anti‐obesity effects of caffeine emerge only when it is consumed in larger quantities remains to be determined.Support or Funding InformationResearch support: NC is supported by American Heart Association grant 16SDG27250156 and Mayo Clinic Center for Clinical and Translational Science grant Marie Ingalls Cardiovascular Research Career Development Fund.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The association of plasma fatty acids levels with hand and knee osteoarthritis

Purpose: Obesity is one of the most important risk factors for osteoarthritis (OA). In addition to increased mechanical loading, systemic factors also likely play a role. Nutrient excess leading to obesity may result in lipotoxicity, with increased levels of circulating fatty acids. However, our knowledge about the effect of different fatty acids on OA is sparse. Therefore, we aimed to investigate the association of plasma saturated fatty acids (SFAs), monounsaturated fatty acid (MUFAs), polyunsaturated fatty acids (PUFAs), omega (n-)3 and n-6 PUFAs on clinically defined hand and knee OA. Since we are in a postprandial state most of the day, both fasting and postprandial samples after a standardized mixed meal were used for the association analyses. Methods: In the population-based Netherlands Epidemiology of Obesity (NEO) study, a total of 6,671 middle-aged participants were recruited from the greater area of Leiden. Clinical hand and knee OA were defined by the ACR clinical classification criteria. Blood samples were obtained after an overnight fast and 150 minutes after consumption of a standardized liquid mixed meal containing 600kCal, with 16% of energy (En%) derived from protein, 50 En% from carbohydrates and 34 En% from fat. EDTA-plasma samples were used for a high-throughput proton nuclear magnetic resonance (NMR) metabolomics platform (Nightingale Health Ltd., Helsinki, Finland) to quantify 159 lipid and metabolite measures. For the present analyses the concentrations of fasting and postprandial total fatty acids, SFAs, MUFAs, PUFAs, n-6 PUFAs and n-3 PUFAs in mmol/l were used. We excluded participants who reported to have inflammatory rheumatic disease or fibromyalgia, with missing physical examination, who were non-fasting at baseline, or reported using lipid-lowering medication. Logistic regression analyses were used to investigate the association between fatty acids and clinical OA phenotypes. All analyses were stratified by sex and corrected for age, education, ethnicity and total body fat percentage. Data are presented as odds ratios (OR) with 95% confidence intervals (CI). Results: In the current analysis 5,328 NEO participants were included, with a mean age of 56 years and 58% were women. Hand OA, knee OA and concurrent hand and knee OA were defined in 8%, 10% and 4%, respectively. After correction for possible confounders, SFA, total PUFA and omega-3 PUFA levels were positively associated with clinical hand OA in men, with OR (95% CI) of 1.26 (1.00 - 1.57), 1.35 (1.00 - 1.82) and 5.27 (1.07 - 25.96) respectively. In women, these associations were not found; however, although not significant, the OR of omega-3 PUFAs and hand OA was 2.49 (0.45 - 13.72). None of the postprandial fatty acid subtypes were statistically significantly associated with knee or concurrent hand and knee OA in both men and women. In comparison, although not significant, results from the analyses with fasting fatty acids showed similar albeit slightly dampened effect estimates. Conclusions: Quantitively measured plasma postprandial SFA and omega-3 PUFA levels were significantly associated with hand OA in men. In women no significant associations were found, however the estimated effect was comparable to the results in men. Intriguingly, although SFA and omega-3 PUFAs are deemed to have opposing effects on inflammation, both were positively associated with hand OA. No significant associations were found between fatty acids and knee and concurrent hand and knee OA. Future research is warranted to replicate the association and determine whether there is a causal role for plasma fatty acid levels in hand OA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Body Composition and Visceral Adipose Tissue in Female Collegiate Equestrian Athletes.

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.

Effects of 6-Month Military Deployment on Physical Fitness, Body Composition, and Selected Health-Related Biomarkers.

Sedliak, M, Sedliak, P, and Vaara, JP. Effects of 6-month military deployment on physical fitness, body composition, and selected health-related biomarkers. J Strength Cond Res 35(4): 1074-1081, 2021-The purpose was to study the effects of 6-month deployment to Afghanistan on physical performance, anthropometrical, and health-related biochemical parameters in soldiers with sedentary to light physical workload shifts. Twenty-five male soldiers (30 ± 4 years) volunteered and were measured before and after the 6-month deployment. Another 25 home-land-based male soldiers (30 ± 6 years) served as controls. Total body fat percentage decreased in deployed soldiers (Pre: 23.2 ± 5.3 vs. Post: 20.8 ± 5.5%, p < 0.05), whereas no change was observed in control (20.2 ± 6.9 vs. 20.5 ± 7.0%). Physical performance improved in deployed soldiers in 4 × 10-m shuttle run (10.86 ± 0.90 vs. 10.49 ± 0.63 seconds) and pull-up test to failure (4.7 ± 3.7 vs. 7.5 ± 6.7 rep.) (p < 0.05) but not in the controls for the respective tests (10.28 ± 0.74 vs. 10.40 ± 0.76 seconds and 10.2 ± 7.8 vs. 10.2 ± 7.5 rep.). Deployed soldiers also improved 5-km run with a simulated combat gear time (29.2 ± 3.1 vs. 27.4 ± 3.0 minutes), whereas in control the time increased (26.4 ± 2.9 vs. 27.8 ± 2.6 minutes, p < 0.05). Load at maximum power output in bench press was improved in deployed soldiers (51.6 ± 11.3 vs. 56.2 ± 12.6 kg, p < 0.05). Serum glucose and creatinine decreased (5.46 ± 0.53 vs. 4.87 ± 0.74 mmol·L-1 and 87.4 ± 10.7 vs. 80.9 ± 10.2 μmmol·L-1, respectively), and hemoglobin and hematocrite increased (15.13 ± 0.82 vs. 16.75 ± 0.85 g·dl-1 and 45.3 ± 1.5 vs. 48.1 ± 2.4%, respectively, p < 0.05) in the deployment group. In conclusion, after 6-month deployment consisting of sedentary and low physical occupational load, soldiers were able to increase their physical fitness and decrease their body fat content and improve selected health-related biochemical parameters. Therefore, the adoption and promotion of leisure-time physical activity in soldiers during deployments is essential to maintain combat readiness.