Sexual dimorphism of body composition

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

Sex differences in impact of sarcopenia on falls in community-dwelling Korean older adults

BACKGROUND

Falls are one of the most serious health problems among older adults. Sarcopenia is characterized by a decrease in muscle mass, strength, and physical function. Due to potentially age-related conditions, both falls and sarcopenia have common risk factors. However, the association between sarcopenia and falls is controversial. Moreover, the sex differences in the impact of sarcopenia on falls is not yet clear. This study aimed to investigate the sex differences in the impact of sarcopenia, defined by the Asian Working Group for Sarcopenia (AWGS), on falls in Korean older adults.

METHODS

In this cross-sectional study, we used data from the Korean Frailty and Aging Cohort Study; 2323 community-dwelling older adults (1111 males and 1212 females) aged 70-84 years were recruited in this cross-sectional study. To evaluate sarcopenia, the AWGS diagnostic algorithm was used. We compared the faller and non-faller groups. We performed unadjusted and fully adjusted logistic regression analyses to evaluate the relationship between sarcopenia, falls, and fall-related fractures.

RESULTS

A total of 239 (24.1%) females in the faller group had a history of falls in the past year, which was statistically higher than that in males (176, 15.8%). In the fully adjusted model, handgrip strength (odds ratio [OR] = 1.508, 95% confidence interval [CI] = 1.028-2.211), and short physical performance battery (OR = 2.068, 95% CI = 1.308-3.271) were significantly lower in the male faller group. However, in the fully adjusted model, the female faller group only showed a significantly low appendicular skeletal muscle mass index (OR = 1.419, 95% CI = 1.058-1.903).

CONCLUSIONS

This large cohort study aimed to identify the sex differences in the incidence of sarcopenia in the older Korean population, using the AWGS diagnostic algorithm, and its correlation with falls and fall-related fractures. The incidence of falls did not increase in the sarcopenia group. Among the sarcopenia components, sex differences affect the history of falls. Therefore, when studying the risk of falls in old age, sex differences should be considered.

The association of a low glycaemic index diet in pregnancy with child body composition at 5 years of age: A secondary analysis of the ROLO study

INTRODUCTION

Childhood obesity remains a significant global health concern. Early intervention through maternal diet during pregnancy represents a possible mode of improving childhood adiposity.

AIM

To examine the impact of a low glycaemic index diet during pregnancy on offspring anthropometry at 5 years of age.

METHODS

This is a secondary analysis of 387 children from the ROLO pregnancy study 5 years' post-intervention. At the follow-up, BMI, circumferences and skinfold thickness were obtained. A subgroup of 103 children had a DXA scan completed. Statistical analyses included Independent sample t tests, Mann Whitney-U tests and chi-square tests to compare the intervention and control groups. Adjusted analysis using linear regression controlled for significant confounders between participants who returned at follow-up and those that did not.

RESULTS

There were no significant differences in BMI (16.05 kg/m² vs 16.16 kg/m² , P = 0.403), general adiposity (36.60 mm vs 36.00 mm, P = 0.920), central adiposity (0.61 mm vs 0.60 mm, P = 0.540), total fat mass (4.91 kg vs 4.71 kg, P = 0.377) or total lean mass (14.29 kg vs 14.56 kg, P = 0.386) between the intervention and control groups, respectively. No associations were observed in 5-year outcomes in adjusted analyses when controlling for maternal age at delivery, maternal early pregnancy BMI, maternal education and gestational age.

CONCLUSION

Our study found no evidence that a low glycaemic index diet in pregnancy impacts offspring anthropometry 5 years' post-intervention. Therefore, modulating maternal carbohydrate quality in pregnancy may not be an appropriate approach to improving weight status in childhood. Future research should investigate the impact of other dietary practices in pregnancy on child health.

Body composition in individuals with cystic fibrosis

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BMI is used to characterize nutritional status but may not accurately depict body composition in CF.

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DXA and bioelectrical impedance are the most commonly used methods for assessing BC.

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Lower fat-free mass associates with worse pulmonary function and greater CF disease severity.

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Fat-free mass associates with greater bone mineral density in individuals with CF.

Because nutritional status is intimately linked with pulmonary function and survival, nutrition has been at the mainstay of cystic fibrosis (CF) care. Body Mass Index (BMI) is traditionally used to define nutritional status because of the ease with which it can be calculated, but it has a number of limitations including its inability to differentiate fat mass (FM) from lean body mass (LBM), the latter thought to confer health advantage. A number of tools are available to quantify body composition including dual-energy x-ray absorptiometry (DXA), bioelectrical impedance, MRI, CT, air displacement plethysmography, and stable isotopes, and these have been used to varying degrees in studies of CF. In CF, LBM tends to be lower for a given BMI, particularly at lower BMI. In adults, lower fat-free mass (FFM) correlates with greater CF disease severity, lower pulmonary function and higher inflammatory markers. FFM is also positively associated with greater bone mineral density, while greater FM is associated with greater loss of lumbar spine bone mineral density over 2 years. In youth, LBM is positively associated with pulmonary function. The predictive value of body composition for functional and clinical outcomes and the role of improving LBM on these outcomes remain undefined. With improvements in BMI accompanying highly-effective modulator therapy, closer evaluations of body composition may inform risk for more traditional, non-CF adult outcomes in CF.

The effect of body composition on strength and power in male and female students

PURPOSE

The aim of this study is to determine and to compare the effect of sex differences in percentage of body fat on the strength and power performances of the legs and arms during short maximal exercise.

METHODS

72 male and 64 female students aged 20 to 23 years were enrolled in this study. After assessing their morphological characteristics (body mass, height and percentage of fat mass), a squat jump test (SJ), a 5 successive jump test (5JT), a hand gripping (HG) and back strength (BS) tests have been conducted for each subject. Male students were re-tested after being weighed down with a weight equivalent to the mean differences in body fat recorded between the two sexes in the form of a loaded worn vest.

RESULTS

Male are 15.7% heavier and 7.4% taller and presented a percentage of fat mass (17.2 ± 1.8%) significantly (p < 0.001) lower than that of women subject (25.0 ± 2.5%) (difference male vs female for fat mass: -45.5%). HG, BS, 5JT and SJ performances were significantly higher in males (44 ± 5 kg, 141 ± 2 kg, 11 ± 1 m and 32.4 ± 2,7 cm, respectively) than in females (31.0 ± 4 kg, 81.6 ± 13 kg, 8.7 ± 0.7 m and 21.1 ± 1.9 cm, respectively). In the control (unloaded) condition, the relative difference between males and females represented 23.5% and 34.7% of the male performances for 5JT and SJ, respectively. In the weighted condition, the relative difference between weighted males and females still represented 11.7% and 23.8% of the weighted male performances for 5JT and SJ, respectively. Cancelling the sex difference in fat mass by adding weight in males reduced by 50.1% the sex difference during 5JT and 31.4% and 71.7% for hight and power results, respectively during SJ test.

CONCLUSION

During short and maximal exercise, male performed better with their hands, back and legs than female students. Excess fat for female students has a disadvantageous effect on vertical and horizontal jumps performances. The persistence of sex differences after weighting of male students indicates that body fat is responsible for 30 to 70% of the observed differences between sexes performances and power outcomes during jump tests.

Relationship of Nutritional Status and Spirometric Parameters in Children with Bronchial Asthma

The potential mechanisms of bronchial asthma (BA) negative modification under the influence of obesity are currently being actively studied. However, at present, the effect of nutritional status on bronchial obstruction in children with BA cannot be considered established. In this regard, the purpose of this work was to study the relationship of spirometric parameters reflecting bronchial patency with nutritional status in children with asthma.

Development and Cross-Validation of a Simple Model to Estimate Percent Body Fat in Persons with Multiple Sclerosis

Background

Persons with multiple sclerosis (MS) have higher body composition variability compared with the general population. Monitoring body composition requires accurate methods for estimating percent body fat (%BF). We developed and cross-validated an equation for estimating %BF from body mass index (BMI) and sex in persons with MS.

Methods

Seventy-seven adults with MS represented the sample for the equation development. A separate sample of 33 adults with MS permitted the equation cross-validation. Dual-energy x-ray absorptiometry (DXA) provided the criterion %BF.

Results

The model including BMI and sex (mean ± SD age: women, 49.2 ± 8.8 years; men, 48.6 ± 9.8 years) had high predictive ability for estimating %BF (P < .001, R² = 0.77, standard error of estimate = 4.06%). Age, MS type, Patient-Determined Disease Steps score, and MS duration did not improve the model. The equation was %BF = 3.168 + (0.895 × BMI) - (10.191 × sex); sex, 0 = woman; 1 = man. The equation was cross-validated in the separate sample (age: women, 48.4 ± 9.4 years; men, 43.8 ± 15.4 years) based on high accuracy as indicated by strong association (r = 0.89, P < .001), nonsignificant difference (mean: 0.2%, P > .05), small absolute error (mean: 2.7%), root mean square error (3.5%), and small differences and no bias in Bland-Altman analysis (mean difference: 0.2%, 95% CI: -6.98 to 6.55, r_s = -0.07, P = .702) between DXA-determined and equation-estimated %BF.

Conclusions

Health care providers can use this developed and cross-validated equation for estimating adiposity in persons with MS when DXA is unavailable.

Cross-fostering selectively bred High Runner mice affects adult body mass but not voluntary exercise

While nursing, mammals progress through critical developmental periods for the cardiovascular, musculoskeletal, and central nervous systems. The suckling period in mammals is therefore especially vulnerable to environmental factors that may affect the "developmental programming" of many complex traits. As a result, various aspects of maternal behavior and physiology can influence offspring in ways that have lasting effects into adulthood. Several recent studies of animal models have shown that maternal effects can partially program adult activity behaviors, which has important implications for health and locomotor performance. Here, we used cross-fostering to test for possible maternal effects on adult wheel-running behavior (voluntary exercise), maximal aerobic capacity during forced exercise (VO₂max), body mass and composition, and organ masses. Subjects were from a line of mice that has been selectively bred for ∼90 generations for high voluntary wheel-running behavior (High Runner; HR) and a non-selected Control (C) line. Adult HR mice run ∼3-fold the daily distances of C mice and have evolved other differences associated with exercise capacity, including elevated VO₂max, reduced body mass and fat mass, and larger hearts. At birth, we fostered offspring to create 4 experimental groups: C pups to other C dams (in-foster), HR pups to other HR dams (in-foster), C pups to HR dams (cross-foster), HR pups to C dams (cross-foster). Thus, all pups were fostered to a different mother. Mice were weaned 3 weeks later, and adult testing began at ∼6 weeks of age. At weaning, pups raised by HR dams were smaller than those raised by C dams for both sexes and as expected, HR pups raised by HR dams weighed less than C pups raised by C dams. As adults, mice raised by HR dams continued to have reduced body masses. As expected, adult HR mice ran approximately 3-fold more than their C counterparts and females ran more than males. However, cross-fostering did not statistically affect any aspect of wheel-running behavior (distance, duration, speed). Similarly, with body mass as a covariate, HR mice had higher VO₂max than C mice, and males had higher VO₂max than females, but cross-fostering had no effect. With body mass as a covariate, cross-fostering had variable effects on adult organ masses in a sex-specific manner. Overall, our results indicate that development of the adult High Runner phenotype does not require rearing by an HR dam, suggesting that high adult activity in humans may be independent of high maternal activity.

Effects of sesame, canola and sesame-canola oils on body weight and composition in adults with type 2 diabetes mellitus: a randomized, triple-blind, cross-over clinical trial

BACKGROUND

Recent investigations have proposed that sesame and canola oils might affect body fat distribution. The present study aimed to examine the effects of sesame, canola and sesame-canola (a blend of sesame and canola oils) oils on body weight and composition in adults with type 2 diabetes mellitus in the context of a randomized, triple-blind, three-way, cross-over clinical trial.

RESULTS

Eligible participants were randomized to replace their regular dietary oil with sesame oil (SO), canola oil (CO) and sesame-canola oil (SCO) (with 40% SO and 60% CO). Treatment periods lasted 9 weeks and were separated by 4-week wash-out periods. Body weight and composition were measured at the beginning, in the middle and at the end of each intervention phase. In total, 93 participants completed the study. After adjustment for confounders, within-period changes were observed following SO and CO intake for body weight (0.34 ± 0.16 kg and 0.33 ± 0.17 kg) and visceral fat (0.13 ± 0.06% and 0.13 ± 0.05%, P < 0.05), respectively. Body mass index was increased within SO intake (0.13 ± 0.05 kg m^-2 , P = 0.031). All of the treatment oils resulted in reduced waist circumference and index of central obesity (P < 0.05). A significant difference in change values was observed for visceral fat between SCO (-0.14 ± 0.07%) and SO (0.12 ± 0.08%) treatment periods in females (P = 0.02).

CONCLUSION

Sesame and canola oils might lead to a modest favorable body fat redistribution by reducing central adiposity, particularly in females; however, the changes were of little clinical importance. © 2021 Society of Chemical Industry.

Sex differences in adipose development in a hunter-gatherer population

OBJECTIVE

Humans are unusually sexually dimorphic in body composition, with adult females having on average nearly twice the fat mass as males. The development of adipose sex differences has been well characterized for children growing up in food-abundant environments, with less known about cross-cultural variation, particularly in populations without exposure to market foods, mechanized technologies, schooling, vaccination, or other medical interventions.

METHODS

To add to the existing cross-cultural data, we fit multiple growth curves to body composition and anthropometric data to describe adipose development for the Savanna Pumé, South American hunter-gatherers.

RESULTS

(1) Little evidence is found for an adiposity 'rebound' at the end of early childhood among either Savanna Pumé girls or boys. (2) Rather, fat deposition fluctuates during childhood, from age ~4 to ~9 years, with no appreciable accumulation until the onset of puberty, a pattern also observed among Congo Baka hunter-gatherers. (3) Body fat fluctuations are more pronounced for girls than boys. (4) The age of peak skeletal, weight, and adipose gains are staggered to a much greater extent among the Savanna Pumé compared to the National Health and Nutrition Examination Survey (NHANES III) reference, suggesting this is an important developmental strategy in lean populations.

CONCLUSION

Documenting growth patterns under diverse preindustrial energetic conditions provides an important baseline for understanding sex differences in body fat emerging today under food abundance.

Associations between Grip Strength and Glycemic Control in Type 2 Diabetes Mellitus: the 2014-2019 Korea National Health and Nutrition Examination Survey

OBJECTIVES

Glycemic control is essential for preventing severe complications in patients with diabetes mellitus. This study investigated the association between grip strength and glycemic control in Korean adults with type 2 diabetes mellitus.

METHODS

From the Korea National Health and Nutrition Examination Survey, 2,498 participants aged over 19 years that patients with diabetes mellitus who did not have a history of cardiovascular disease or cancer were selected for analysis. Grip strength was assessed using a handheld dynamometer and was represented as age-specific and sex-specific tertiles. Multivariable logistic regression was performed to calculate the odds ratio (OR) and 95% confidence interval (CI) of glycemic control according to the grip strength tertiles.

RESULTS

A significantly lower probability (OR, 0.67; 95% CI, 0.47 to 0.97) for glycemic control was found in the lowest tertile of grip strength compared to the highest tertile. Furthermore, a subgroup analysis by sex only found significant associations between grip strength and glycemic control in males.

CONCLUSIONS

Lower grip strength was associated with poor glycemic control in patients with diabetes mellitus, especially in males. However, further studies are needed to confirm the causal relationship between grip strength and glycemic control.

Pubertal Suppression, Bone Mass, and Body Composition in Youth With Gender Dysphoria

BACKGROUND AND OBJECTIVES

Puberty onset and development contribute substantially to adolescents' bone mass and body composition. Our objective with this study was to examine the effects of gonadotropin-releasing hormone agonists (GnRHa) on these puberty-induced changes among youth with gender dysphoria (GD).

METHODS

Medical records of the endocrine diversity clinic in an academic children's hospital were reviewed for youth with GD seen from January 2006 to April 2017 with at least 1 baseline dual-energy radiograph absorptiometry measurement.

RESULTS

At baseline, transgender females had lower lumbar spine (LS) and left total hip (LTH) areal bone mineral density (aBMD) and LS bone mineral apparent density (BMAD) z scores. Only 44.7% of transgender youth were vitamin D sufficient. Baseline vitamin D status was associated with LS, LTH aBMD, and LS BMAD z scores. Post-GnRHa assessments revealed a significant drop in LS and LTH aBMD z scores (transgender males and transgender females) without fractures and LS BMAD (transgender males), an increase in gynoid (fat percentage), and android (fat percentage) (transgender males and transgender females), and no changes in BMI z score.

CONCLUSIONS

GnRHa monotherapy negatively affected bone mineral density of youth with GD without evidence of fractures or changes in BMI z score. Transgender youth body fat redistribution (android versus gynoid) were in keeping with their affirmed gender. The majority of transgender youth had vitamin D insufficiency or deficiency with baseline status associated with bone mineral density. Vitamin D supplementation should be considered for all youth with GD.

Ontogenetic variation in human nasal morphology

Internal nasal cavity morphology has long been thought to reflect respiratory pressures related to heating and humidifying inspired air. Yet, despite the widely recognized importance of ontogeny in understanding climatic and thermoregulatory adaptations, most research on nasal variation in modern and fossil humans focuses on static adult morphology. This study utilizes cross-sectional CT data of three morphologically distinct samples (African, European, Arctic) spanning from infancy to adulthood (total n = 321). Eighteen landmarks capturing external and internal regions of the face and nose were subjected to generalized Procrustes and form-space principal component analyses (separately conducted on global and individual samples) to ascertain when adult-specific nasal morphology emerges during ontogeny. Across the global sample, PC1 (67.18% of the variation) tracks age-related size changes regardless of ancestry, while PC2 (6.86%) differentiates between the ancestral groups irrespective of age. Growth curves tracking morphological changes by age-in-years indicate comparable growth trajectories across all three samples, with the majority of nasal size and shape established early in ontogeny (<5 years of age). Sex-based trends are also evident, with females exhibiting a more truncated growth period than males, particularly for nasal height dimensions. Differences are also evident between the anterior and posterior nose, with the height and breadth dimensions of the anterior nasal aperture and nasal cavity showing differential ontogenetic patterns compared to the choanae. Cumulatively, these results suggest that multiple selective pressures influence human nasal morphology through ontogenetic processes, including metabolic demands for sufficient oxygen intake and climatic demands for adequate intranasal air conditioning.

A geometric morphometric assessment of shape variation in adult pelvic morphology

OBJECTIVES

In humans, the pelvis is the most sexually dimorphic skeletal element and is often utilized in aging and sexing remains. The pelvis has become greatly relied upon in anthropological research (e.g., forensics, demographics, obstetrics, evolutionary history); however, pelvis morphology is highly variable, and very little is known about the nature, sources, patterning, and interpretation of this variation. This study aims to quantify pelvis shape variation, document sexual shape variation, and estimate the plasticity of morphology. This will ultimately give greater ability to interpret modern, archaeological, and evolutionary patterns to gain deeper insight into processes which shape human anatomy.

MATERIALS AND METHODS

Using a sample of 129 Medieval Danish skeletons, shape variation is documented in the greater sciatic notch (GSN), iliac crest (IC), arcuate line (AL), and sub-pubic angle (SPA) using 3D geometric morphometrics. The landmarking method applied here has the advantage of being applicable to fragmentary remains, rather than requiring whole bones. This allows it to be easily applied to archaeological samples and for the interpretation of separate bone features. Differences in shape were statistically analyzed by principle component analysis, linear discriminate analysis, and morphological disparity. Relationships between maximum femur length, body mass, and shape centroid size were also test by allometric regression.

RESULTS

Results quantify the sexual dimorphism and shape variation present in these features. The GSN shape is the most variable, while the AL is the least. Similarly, the IC is the only feature which shows almost no dimorphism in shape, and instead best reflects lifestyle/activity patterns. Evidence of dimorphism in the IC is likely a result of cultural labor patterns rather than genetic and hormonal influence. Finally, the shapes of the GSN, AL, and SPA are more related to body mass than to femur length, such that individuals with increased mass exhibit more classically "male" shapes and those with less mass have more "female" shapes.

DISCUSSION

The results have important implications for the evolution of pelvic anatomy, and sexual dimorphism, but also highlight the plasticity inherent in pelvic morphology. Analyzing pelvis features separately in a clearly defined, relatively genetically homogenous population gives insight into the determinants of bone morphology, which are not readily observable by other means. The relationship between body mass and shape suggests dimorphism in body size and composition may affect bone shape.

Pain sensitivity does not differ between obese and healthy weight individuals

Introduction

There is emerging evidence suggesting a relationship between obesity and chronic pain.

Objectives

The aim of this study was to determine whether pain-free obese individuals display altered pain responses to acute noxious stimuli, thus raising the possibility of greater pain sensitivity and potential susceptibility for chronic pain development.

Methods

Psychophysical and anthropometric data were collected from 38 individuals with an obese body mass index (BMI) classification (BMI ≥ 30) and 41 age/sex-matched individuals of a healthy BMI (BMI < 24.9). Because BMI may be an inaccurate index of obesity, additional anthropometric parameters of central adiposity and percent body fat were examined. Pain responses to suprathreshold noxious heat and cold stimuli were examined. Subjects provided pain intensity and unpleasantness ratings to noxious heat (49°C) applied at varying durations and locations (ventral forearm/lower leg). Cold pain ratings, thresholds, and tolerances were obtained after immersion of the hand in a cold-water bath (0-2°C). Between-group differences in pain responses, as well as relationships between pain responses and obesity parameters, were examined. Importantly, confounds that may influence pain such as anxiety, depression, impulsivity, sleepiness, and quality of life were assessed.

Results

No between-group differences in pain sensitivity to noxious heat and cold stimuli were found. No relationships were found between central adiposity or body fat (percentage or distribution) and pain responses to noxious heat or cold stimuli.

Conclusions

Obesity has minimal influence on pain sensitivity. Accordingly, it is unlikely that obesity alone increases susceptibility for chronic pain development through amplification of nociceptive processes.

Gut Microbiota in Adipose Tissue Dysfunction Induced Cardiovascular Disease: Role as a Metabolic Organ

The gut microbiome has emerged as a key regulator of host metabolism. Accumulating evidence has indicated that the gut microbiota is involved in the development of various human diseases. This association relies on the structure and metabolites of the gut microbiota. The gut microbiota metabolizes the diet ingested by the host into a series of metabolites, including short chain fatty acids, secondary bile acids, trimethylamine N-oxide, and branched-chain amino acids, which affects the physiological processes of the host by activating numerous signaling pathways. In this review, we first summarize the various mechanisms through which the gut microbiota influences adipose tissue dysfunction and metabolic processes that subsequently cause cardiovascular diseases, highlighting the complex interactions between gut microbes, their metabolites, and the metabolic activity of the host. Furthermore, we investigated the current status of clinical therapies for adipose tissue dysfunction directed at the gut microbiota. Finally, we discuss the challenges that remain to be addressed before this field of research can be translated to everyday clinical practice.

Age and Sex: Impact on adipose tissue metabolism and inflammation

Age associated chronic inflammation is a major contributor to diseases with advancing age. Adipose tissue function is at the nexus of processes contributing to age-related metabolic disease and mediating longevity. Hormonal fluctuations in aging potentially regulate age-associated visceral adiposity and metabolic dysfunction. Visceral adiposity in aging is linked to aberrant adipogenesis, insulin resistance, lipotoxicity and altered adipokine secretion. Age-related inflammatory phenomena depict sex differences in macrophage polarization, changes in T and B cell numbers, and types of dendritic cells. Sex differences are also observed in adipose tissue remodeling and cellular senescence suggesting a role for sex steroid hormones in the regulation of the adipose tissue microenvironment. It is crucial to investigate sex differences in aging clinical outcomes to identify and better understand physiology in at-risk individuals. Early interventions aimed at targets involved in adipose tissue adipogenesis, remodeling and inflammation in aging could facilitate a profound impact on health span and overcome age-related functional decline.

Youth Perceptions of Sport-Confidence

ABSTRACT

Zuk, EF, Maksymiw, K, Evanovich, J, McGarry, JE, Root, HJ, and Distefano, LJ. Youth perceptions in sport-confidence. J Strength Cond Res XX(X): 000-000, 2021-Sport-confidence is an important construct that is often missed during physical activity interventions in youth. Male and female children might display differences in sport-confidence that influences their activity levels. The purpose of this study is to assess any association between sport-confidence and gender in elementary school and middle-school children. All 286 children {(boys [ES: n = 71, age = 8±1 years; MS: n = 63, 11±1 years]; girls [ES: n = 67, 7±1 years; MS: n = 85, 11±1 years])} completed the Physical Literacy Assessment for Youth-Self Questionnaire. Separate chi-square tests of the association were used to evaluate the association between gender and sport-confidence among elementary (grades K-4) and middle-school (grades 5-8) children because of varying injury and participation rates for these groups, for each relevant question with a significance set at p ≤ 0.05. For elementary school children, there were no significant associations between genders and sport-confidence (p > 0.05). In middle-school children, there were significant associations detected for learning new skills (ϕ = 0.12; p = 0.031), perception of skill (ϕ = 0.12; p = 0.054), confidence in activity (ϕ = 0.17; p = 0.035), and being the best in the class (ϕ = 0.15; p = 0.048) between genders and sport-confidence. For all results, boys displayed more sport-confidence than girls. Education for key stakeholders about the importance of including sport-confidence in physical activity interventions is integral in promoting life-long activity, specifically in middle-school girls.

Risk factors in adolescents as predictors of arterial hypertension in adults: Protocol for a systematic review

This is a protocol of a review paper, and there is no abstract. This review is part of a doctoral project that aims to develop a discrete event simulation model to predict how many adolescents may become hypertensive in adulthood. We will use data from the Brazilian study of cardiovascular risks in adolescents, called ERICA (Portuguese acronym). This study may help promote adherence to disease prevention protocols.

Sexing white 2D footprints using convolutional neural networks

Footprints are left, or obtained, in a variety of scenarios from crime scenes to anthropological investigations. Determining the sex of a footprint can be useful in screening such impressions and attempts have been made to do so using single or multi landmark distances, shape analyses and via the density of friction ridges. Here we explore the relative importance of different components in sexing two-dimensional foot impressions namely, size, shape and texture. We use a machine learning approach and compare this to more traditional methods of discrimination. Two datasets are used, a pilot data set collected from students at Bournemouth University (N = 196) and a larger data set collected by podiatrists at Sheffield NHS Teaching Hospital (N = 2677). Our convolutional neural network can sex a footprint with accuracy of around 90% on a test set of N = 267 footprint images using all image components, which is better than an expert can achieve. However, the quality of the impressions impacts on this success rate, but the results are promising and in time it may be possible to create an automated screening algorithm in which practitioners of whatever sort (medical or forensic) can obtain a first order sexing of a two-dimensional footprint.

Fat-to-Muscle Ratios and the Non-Achievement of LDL Cholesterol Targets: Analysis of the Korean Genome and Epidemiology Study

Maintaining optimal low-density lipoprotein (LDL) cholesterol levels is necessary to prevent cardiovascular disease (CVD). Excessive fat mass and decreased muscle mass are both associated with increased risks of developing dyslipidemia. Thus, we investigated the longitudinal relationship between the fat-to-muscle ratio (FMR) and the non-achievement of LDL cholesterol targets. We analyzed a total of 4386 participants aged 40–69 years from the Korean Genome and Epidemiology Study. FMR was defined as the ratio of total fat mass to total muscle mass, measured by bioelectrical impedance. The non-achievement of an LDL cholesterol target was defined as an LDL cholesterol level higher than the established target level according to individual CVD risk. The adjusted hazard ratios and 95% confidence interval for the incidence of non-achievement of LDL cholesterol targets for the sex-specific middle and highest tertiles vs. the referent lowest tertile of FMR were 1.56 (1.29–1.90) and 1.86 (1.47–2.31) in men and 1.40 (1.18–1.66) and 1.31 (1.06–1.62) in women after adjusting confounders. Our findings suggest that FMR, a novel indicator of the combined effects of fat and muscle mass, is useful for predicting non-achievement of LDL cholesterol targets.

Caloric restriction alleviates radiation injuries in a sex-dependent fashion

Safe and effective regimens are still needed given the risk of radiation toxicity from iatrogenic irradiation. The gut microbiota plays an important role in radiation damage. Diet has emerged as a key determinant of the intestinal microbiome signature and function. In this report, we investigated whether a 30% caloric restriction (CR) diet may ameliorate radiation enteritis and hematopoietic toxicity. Experimental mice were either fed ad libitum (AL) or subjected to CR preconditioning for 10 days and then exposed to total body irradiation (TBI) or total abdominal irradiation (TAI). Gross examinations showed that short-term CR pretreatment restored hematogenic organs and improved the intestinal architecture in both male and female mice. Intriguingly, CR preconditioning mitigated radiation-induced systemic and enteric inflammation in female mice, while gut barrier function improved in irradiated males. 16S rRNA high-throughput sequencing showed that the frequency of pro-inflammatory microbes, including Helicobacter and Desulfovibrionaceae, was reduced in female mice after 10 days of CR preconditioning, while an enrichment of short-chain fatty acid (SCFA)-producing bacteria, such as Faecalibaculum, Clostridiales, and Lactobacillus, was observed in males. Using fecal microbiota transplantation (FMT) or antibiotic administration to alter the gut microbiota counteracted the short-term CR-elicited radiation tolerance of both male and female mice, further indicating that the radioprotection of a 30% CR diet depends on altering the gut microbiota. Together, our findings provide new insights into CR in clinical applications and indicate that a short-term CR diet prior to radiation modulates sex-specific gut microbiota configurations, protecting male and female mice against the side effects caused by radiation challenge.

Developing a New Curvilinear Allometric Model to Improve the Fit and Validity of the 20-m Shuttle Run Test as a Predictor of Cardiorespiratory Fitness in Adults and Youth

BACKGROUND AND OBJECTIVES

Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a more biologically and physiologically interpretable model (construct validity). The purposes of this study were to explore whether allometry can provide a more valid predictor of CRF using 20 mSRT compared with Léger's equation/model.

METHODS

We fitted and compared Léger's original model and an alternative allometric model using two cross-sectional datasets (youth, n = 306; adult n = 105) that contained measurements of CRF ([Formula: see text]/[Formula: see text]) and 20 mSRT performance. Quality-of-fit was assessed using explained variance (R²) and Bland and Altman's limits of agreement.

RESULTS

The allometric models provided superior fits for the youth (explained variance R² = 71.9%) and adult (R² = 77.7%) datasets compared with Léger's equation using their original fixed (R² = 35.2%) or re-estimated parameter models (R² = 65.9%), confirming that the allometric models demonstrate acceptable criterion validity. However, the allometric models also identified a non-linear "J-shaped" increase in energy cost ([Formula: see text]/[Formula: see text]) with faster final shuttle-run speeds (fitted speed exponent = 1.52; 95% CI 1.38-1.65).

CONCLUSION

Not only do allometric models provide more accurate predictions of CRF ([Formula: see text]/[Formula: see text]; ml kg^-1 min^-1) for both youth and adults (evidence of criterion validity), the "J-shaped" rise in energy demand with increasing final shuttle-run speed also provides the evidence of construct validity, resulting in a more plausible, physiologically sound, and interpretable model.

High-Resolution Proteomic Profiling Shows Sexual Dimorphism in Zebrafish Heart-Associated Proteins

Understanding the molecular basis of sexual dimorphism in the cardiovascular system may contribute to the improvement of the outcome in biological, pharmacological, and toxicological studies as well as on the development of sex-based drugs and therapeutic approaches. Label-free protein quantification using high-resolution mass spectrometry was applied to detect sex-based proteome differences in the heart of zebrafish Danio rerio. Out of almost 3000 unique identified proteins in the heart, 79 showed significant abundance differences between male and female fish. The functional differences were mapped using enrichment analyses. Our results suggest that a large amount of materials needed for reproduction (e.g., sugars, lipids, proteins, etc.) may impose extra pressure on blood, vessels, and heart on their way toward the ovaries. In the present study, the female's heart shows a clear sexual dimorphism by changing abundance levels of numerous proteins, which could be a way to safely overcome material-induced elevated pressures. These proteins belong to the immune system, oxidative stress response, drug metabolization, detoxification, energy, metabolism, and so on. In conclusion, we showed that sex can induce dimorphism at the molecular level in nonsexual organs such as heart and must be considered as an important factor in cardiovascular research. Data are available via ProteomeXchange with identifier PXD023506.

Treatment Strategies for Generator Pocket Pain

OBJECTIVE

Generator site pain is a relatively common phenomenon in patients undergoing spinal cord stimulation (SCS) that complicates management and effective pain relief. This pain may be managed conservatively, with repositioning of the battery and, in some cases, with explant. Here we explore our experience with management of generator site pain ("pocket pain") in a large single-center study.

METHODS

All SCS permanent implants and implantable pulse generator (IPG) placements over 9 years were reviewed. Of 785 cases, we identified 43 patients with pocket pain (5.5%). Demographics and treatments of the pocket pain cohort were analyzed.

RESULTS

The mean age (± SEM) of the pocket pain cohort was 46.86 ± 1.06, and there were 10/33 males/females. Females were overrepresented in pocket pain cohort (76.7%) when compared with the total SCS cohort (59.0%) (X2 = 5.93, P = 0.015). Diagnosis included failed back surgery syndrome (51.2%), complex regional pain syndrome (23.3%), and chronic neuropathic pain (25.5%). No patients improved with conservative therapy. All patients either went on to revision (n = 23) or explant (n = 20). Time from initial surgery to development of pocket pain was 7.5 months (range: 0.3-88) and from pocket pain to revision surgery was 4.5 months (range: 0.4-26). In addition, significantly more pocket pain patients (65.1%) had workers' compensation (WC) insurance compared with patients without pocket pain (24.9%) (X2 = 33.3, P < 0.001).

CONCLUSION

In our institutional experience, pocket pain was inadequately managed with conservative treatments. Being female and having SCS filed under WC increased risk of pocket pain. Future work will explore the nuances in device placement based on body shape and manual activity responsibilities.

Substrate metabolism during exercise: sexual dimorphism and women's specificities

The aim of this review is to discuss sexual dimorphism of energy metabolism, and to describe the impact of women's hormonal status on substrate oxidation during exercise. Many evidences indicate that sex steroids play a pivotal role in the sex-related differences of body composition and energy substrate storage. Compared with men, women rely more on fat and less on carbohydrates at the same relative exercise intensity. Scientific data suggest that 17-β oestradiol is a key hormone for the regulation of body composition and substrate metabolism. However, in women, measurements with stable isotopic tracers did not highlight any difference in whole-body substrate oxidation rates between the follicular and luteal phases of the menstrual cycle during endurance exercise. The remaining discrepancies about the effect of menstrual cycle-related hormone fluctuations on substrate oxidation could be partly explained by the exercise intensity, which is an important regulator of substrate oxidation. Due to their specific nature and concentration, the synthetic ovarian hormones contained in oral contraceptives also influence substrate metabolism during endurance exercise. However, more studies are needed to confirm that oral contraceptives increase lipolytic activity during endurance exercise without any substantial (or detectable) effect on substrate utilization. Pregnancy and menopause also modify body composition and substrate utilization during exercise through specific hormonal fluctuations.This review highlights that the hormonal status is likely to affect substrate oxidation during exercise in women emphasizing the need to take it into consideration to optimize their health and performance.

Sex-specific differences in somatic investment and strategies of physical activity among Portuguese schoolchildren

OBJECTIVES

Physical activity (PA) is required for healthy growth, development, and maturation and plays an important role in the prevention of overweight and obesity in childhood and adolescence. Sex-differences in PA levels are well documented, with boys spending more time in PA, especially in moderate-to-vigorous activities. Following the Life History Theory, our aim is to study if PA affects the fat tissues increases during childhood and juvenile phases in both sexes.

METHODS

Time spent in sedentary, light, and moderate-to-vigorous PA levels were measured in a sample of 415 Portuguese children and juveniles (207 females/208 males; aged 6-11 years), using an accelerometer for 7 days. Skinfolds related with body fat were objectively collected and socioeconomic status factors were reported using a parental questionnaire.

RESULTS

The outcomes show that girls' and boys' fat variables increased during the end of the childhood and the juvenile phase. However, these variables were differently affected by PA. Girls increased fat variables with the sedentary activity while boys decreased fat variables with moderate-to-vigorous PA. Alike, active boys but not girls reduced the fat increase tendency with age.

CONCLUSIONS

Although both sexes displayed a general fat increment with age, moderate-to-vigorous PA dampens the increase only in boys. In fact, active girls increased body fat in the same manner as non-active girls. From an evolutionary perspective, it could explain sex-specific somatic strategies related to future reproduction or, with future mating and intrasexual competition.

Genetics of Body Fat Distribution: Comparative Analyses in Populations with European, Asian and African Ancestries

Preferential fat accumulation in visceral vs. subcutaneous depots makes obese individuals more prone to metabolic complications. Body fat distribution (FD) is regulated by genetics. FD patterns vary across ethnic groups independent of obesity. Asians have more and Africans have less visceral fat compared with Europeans. Consequently, Asians tend to be more susceptible to type 2 diabetes even with lower BMIs when compared with Europeans. To date, genome-wide association studies (GWAS) have identified more than 460 loci related to FD traits. However, the majority of these data were generated in European populations. In this review, we aimed to summarize recent advances in FD genetics with a focus on comparisons between European and non-European populations (Asians and Africans). We therefore not only compared FD-related susceptibility loci identified in three ethnicities but also discussed whether known genetic variants might explain the FD pattern heterogeneity across different ancestries. Moreover, we describe several novel candidate genes potentially regulating FD, including NID2, HECTD4 and GNAS, identified in studies with Asian populations. It is of note that in agreement with current knowledge, most of the proposed FD candidate genes found in Asians belong to the group of developmental genes.

The patterns of left ventricular alteration by adipose tissue distribution: implication for heart failure prevention

AIMS

The current study aimed to evaluate the associations between general and abdominal obesity with left ventricular (LV) structure and function and whether these associations differed by sex.

METHODS AND RESULTS

This is a community-based cross-sectional study, and 971 hypertensive individuals without overt cardiovascular disease were included. General obesity was defined as body mass index (BMI) ≥ 28 kg/m² , and abdominal obesity was defined as waist circumference (WC) ≥ 90 cm for men and ≥85 cm for women. The associations between general and abdominal obesity with LV structure and function were examined using linear regression analysis, and the interaction by sex was performed. The mean age was 66.5 ± 11.4 years, and women accounted for 62%. General obese individuals (n = 205) were more likely to have concentric remodelling, LV hypertrophy, and worse diastolic function. Similar differences were observed in abdominal obese individuals (n = 593). General obesity was associated with LV end-diastolic volume, LV mass, left atrial volume, and septal E/e' ratio after adjusting for WC and clinical covariates; and abdominal obesity was associated with septal e' velocity after adjusting for BMI and clinical covariates. The associations between general obesity with LV structure and function did not differ by sex, while the magnitudes of the associations between abdominal obesity with LV mass and septal e' velocity were greater in men.

CONCLUSIONS

General and abdominal obesity were associated with different patterns of LV structural and functional alterations, stressing the importance of incorporating BMI and WC measurements into assessing obesity-related LV alterations.

High prevalence of overall overweight/obesity and abdominal obesity amongst adolescents: An emerging nutritional problem in rural high schools in Limpopo Province, South Africa

BACKGROUND

As the gap in nutritional profiles between urban and rural rapidly reduces because of nutrition transition, rural adolescents are likely to engage in urban lifestyle behaviours.

AIM

The study determined the prevalence of overweight/obesity amongst adolescents in rural high schools and the association with selected factors.

SETTING

Fetakgomo Municipality in rural Limpopo Province, South Africa.

METHODS

A cross-sectional study was conducted amongst 378 adolescents selected through multistage sampling from high schools. Data collected were socio-demography, nutritional knowledge, dietary practices and anthropometry. The International Obesity Task Force age and sex-specific body mass index (BMI) cut-off values were used to determine overweight/obesity, whilst adult BMI cut-off values were used for those ≥ 18 years. Waist-to-height ratio (WHtR) greater than 0.5 indicated abdominal obesity, as well as waist circumference (WC) and waist-to-hip ratio (WHR) above the cut-off values.

RESULTS

The proportion of overweight/obesity amongst adolescents was 35%, whilst 25% had abdominal obesity by WHR and 21% by WHtR. Multivariate logistic regression showed that being a girl (AOR = 2.9, 95% CI: 1.74-4.85), older adolescent (AOR = 3.1, 95% CI: 1.57-6.29) and living in a household with employed adults (AOR = 2.3, 95% CI: 1.19-4.51) were associated with increased odds of being overweight/obese. Eating breakfast was associated with reduced odds of being overweight/obese (AOR = 0.6, 95% CI: 0.34-0.97).

CONCLUSION

Overweight/obesity and abdominal obesity amongst adolescents were more prevalent than underweight. The Integrated School Health Programme should have clear guidelines on food items served and sold at schools.

Effects of early-life exposure to Western diet and voluntary exercise on adult activity levels, exercise physiology, and associated traits in selectively bred High Runner mice

Exercise behavior is under partial genetic control, but it is also affected by numerous environmental factors, potentially including early-life experiences whose effects persist into adulthood. We studied genetic and early-life environmental effects on wheel-running behavior in a mouse model that includes four replicate high runner (HR) lines selectively bred for increased voluntary wheel running as young adults and four non-selected control (C) lines. In a full factorial design, mice from each line were granted wheel access or not and administered either standard or Western diet (WD) from weaning (3 weeks old) to 6 weeks of age (sexual maturity). In addition to acute effects, after a washout period of 8 weeks (∼6 human years) in which all mice had standard diet and no wheel access, we found both beneficial and detrimental effects of these early-life exposures. During the first week of treatments, WD increased distance run by 29% in C mice and 48% in HR mice (significant Diet × Linetype interaction), but diet effects disappeared by the third week. Across the three weeks of juvenile treatment, WD significantly increased fat mass (with lean mass as a covariate). Tested as adults, early-life exercise increased wheel running of C mice but not HR mice in the first week. Early-life exercise also reduced adult anxiety-like behavior and increased adult fasted blood glucose levels, triceps surae mass, subdermal fat pad mass, and brain mass, but decreased heart ventricle mass. Using fat mass as a covariate, early-life exercise treatment increased adult leptin concentration. In contrast, early-life WD increased adult wheel running of HR mice but not C mice. Early-life WD also increased adult lean mass and adult preference for Western diet in all groups. Surprisingly, early-life treatment had no significant effect on adult body fat or maximal aerobic capacity (VO2max). No previous study has tested for combined or interactive effects of early-life WD and exercise. Our results demonstrate that both factors can have long-lasting effects on adult voluntary exercise and related phenotypes, and that these effects are modulated by genetic background. Overall, the long-lasting effects of early-life exercise were more pervasive than those of WD, suggesting critical opportunities for health intervention in childhood habits, as well as possible threats from modern challenges. These results may be relevant for understanding potential effects of activity reductions and dietary changes associated with the obesity epidemic and COVID-19 pandemic.

The heritability of body composition

BACKGROUND

Physical growth during childhood and adolescence is influenced by both genetic and environmental factors. Heritability, the proportion of phenotypic variance explained by genetic factors, has been demonstrated for stature and weight status. The aim of this study was to explore the heritability of body composition.

METHODS

A real-life, observational study of the children and adolescents referred to the Endocrine Unit in a tertiary medical center. In January 2018, body composition by means of bioimpedance analysis (BIA) was implemented as part of the standard intake assessment of subjects referred for endocrine consultation. The clinic BIA database was searched for subjects with the term "observation of growth" as the sole reason for referral. BIA of 114 triads of healthy subjects aged 5-18 years and their parents were analyzed. The BIA report included the following data: fat mass, fat percentage, truncal fat percentage and muscle mass. Calculated variables included: appendicular skeletal muscle mass (ASMM = the sum of muscle mass of four limbs), muscle-to-fat ratio [MFR = ASMM (kg)/fat mass (kg)] and sarcopenic index [(SI = ASMM(kg)/height (meter)²]. Data collection from medical files included pubertal stage and home address for socioeconomic position grading.

RESULTS

There were sex differences in body composition parameters in both the prepubertal and pubertal subjects. The boys among the prepubertal subjects had a lower fat percentage on average than girls (p = 0.020). Among the adolescents, boys on average had lower fat percentage (p = 0.011), higher sarcopenic index (p = 0.021), and higher muscle-to-fat ratio (p < 0.001), than adolescent girls. Correlation analyses between body composition parameters of all participants revealed significant correlations in the sarcopenic index of prepubertal children and their parents (boys-fathers: r = 0.380, p = 0.050; boys-mothers: r = 0.435, p = 0.026; girls-fathers: r = 0.462, p = 0.012; girls-mothers: r = 0.365, p = 0.050) and adiposity indices (fat percentage, truncal fat percentage and muscle-to-fat ratio) of prepubertal boys and their mothers (r = 0.438, p = 0.025; r = 0.420, p = 0.033, and r = 0.478, p = 0.014, respectively). There were no associations between body composition parameters of adolescents and their parents. Socioeconomic position adversely affected fat percentage in adolescent girls and mothers.

CONCLUSIONS

Heritable body composition traits were demonstrated in childhood but not in adolescence, suggesting that environmental influence has a more telling effect during teenage years.

Beneficial effects of a decreased meal frequency on nutrient utilization, secretion of luteinizing hormones and ovarian follicular development in gilts

Background

Replacement gilts are typically fed ad libitum, whereas emerging evidence from human and rodent studies has revealed that time-restricted access to food has health benefits. The objective of this study was to investigate the effect of meal frequency on the metabolic status and ovarian follicular development in gilts.

Methods

A total of 36 gilts (Landrace × Yorkshire) with an age of 150±3 d and a body weight of 77.6±3.8 kg were randomly allocated into one of three groups (n = 12 in each group), and based on the group allocation, the gilts were fed at a frequency of one meal (T1), two meals (T2), or six meals per day (T6) for 14 consecutive weeks. The effects of the meal frequency on growth preference, nutrient utilization, short-chain fatty acid production by gut microbial, the post-meal dynamics in the metabolic status, reproductive hormone secretions, and ovarian follicular development in the gilts were measured.

Results

The gilts in the T1 group presented a higher average daily gain (+ 48 g/d, P < 0.05) and a higher body weight (+ 4.9 kg, P < 0.05) than those in the T6 group. The meal frequency had no effect on the apparent digestibility of dry matter, crude protein, ether extract, ash, and gross energy, with the exception that the T1 gilts exhibited a greater NDF digestibility than the T6 gilts (P < 0.05). The nitrogen balance analysis revealed that the T1 gilts presented decreased urine excretion of nitrogen (− 8.17 g/d, P < 0.05) and higher nitrogen retention (+ 9.81 g/d, P < 0.05), and thus exhibited higher nitrogen utilization than the T6 gilts. The time-course dynamics of glucose, α-amino nitrogen, urea, lactate, and insulin levels in serum revealed that the T1 group exhibited higher utilization of nutrients after a meal than the T2 or T6 gilts. The T1 gilts also had a higher acetate content and SCFAs in feces than the T6 gilts (P < 0.05). The age, body weight and backfat thickness of the gilts at first estrous expression were not affected by the meal frequency, but the gilts in the T1 group had higher levels of serum luteinizing hormone on the 18th day of the 3rd estrus cycle and 17β-estradiol, a larger number of growing follicles and corpora lutea, and higher mRNA expression levels of genes related to follicular development on the 19th day of the 3rd estrus cycle.

Conclusions

The current findings revealed the benefits of a lower meal frequency equal feed intake on nutrient utilization and reproductive function in replacement gilts, and thus provide new insights into the nutritional strategy for replacement gilts, and the dietary pattern for other mammals, such as humans.

Energetics as a driver of human morphological thermal adaptation; evidence from female ultra-endurance athletes

Functional benefits of the morphologies described by Bergmann's and Allen's rules in human males have recently been reported. However, the functional implications of ecogeographical patterning in females remain poorly understood. Here, we report the findings of preliminary work analysing the association between body shape and performance in female ultramarathon runners (n = 36) competing in hot and cold environments. The body shapes differed between finishers of hot and cold races, and also between hot race finishers and non-finishers. Variability in race performance across different settings supports the notion that human phenotype is adapted to different thermal environments as ecogeographical patterns have reported previously. This report provides support for the recent hypothesis that the heightened thermal strain associated with prolonged physical activity in hot/cold environments may have driven the emergence of thermally adaptive phenotypes in our evolutionary past. These results also tentatively suggest that the relationship between morphology and performance may be stronger in female vs. male athletes. This potential sex difference is discussed with reference to the evolved unique energetic context of human female reproduction. Further work, with a larger sample size, is required to investigate the observed potential sex differences in the strength of the relationship between phenotype and performance.

Fluctuating asymmetry, a marker of poor growth quality, is associated with adult male metabolic rate

OBJECTIVES

Life history theory, a branch of evolutionary theory, predicts the existence of trade-offs in energetic allocation between competing physiological functions. The core metabolic cost of self-maintenance, measured by resting metabolic rate (RMR), represents a large component of human daily energy expenditure. Despite strong selective pressures for energetic frugality and high observed interindividual variation in RMR, the link between RMR and energetic allocation to life-history traits remains understudied in humans.

MATERIALS

In a sample of 105 (m = 57, f = 48), we investigated the relationship between adult RMR and investment in growth quality, as measured by fluctuating asymmetry (FA).

RESULTS

Measurement of RMR and FA in university rowers revealed a significant positive correlation amongst males (n = 57, r = 0.344, p = 0.005, 1-tailed; standardized 95% CI, 0.090 to 0.598). Convincing evidence for a correlation among females was not found (n = 48, r = 0.142, p = 0.169, 1-tailed, standardized 95% CI, -0.152 to 0.435).

DISCUSSION

The data suggest that low-quality asymmetrical growth is associated with later-life metabolic inefficiencies in males. Energetic investment in processes (likely concerning the stress-response) unrelated to growth during childhood may thereby trade-off against adult metabolic efficiency. We suggest that the presence of a relationship between RMR and FA in males but not females may be explained by the additional metabolic strain associated with larger body size and increased male muscularity, which may amplify the inefficiencies arising from low-quality growth.

Sex-related differences in accumulated O2 deficit incurred by high-intensity rowing exercise during childhood and adolescence

PURPOSE

The aims of the present study were to determine during childhood and adolescence (i) the effect of sex on non-oxidative energy production, quantified by the accumulated oxygen deficit (AOD), and (ii) the influence of AOD on high-intensity performance.

METHODS

Thirty-nine boys and 35 girls aged 10-17 years performed a 60 s all-out test on a rowing ergometer to determine AOD and mean power output (MPO). Multiplicative allometric modelling was used to assess the concurrent effects of lean body mass (LBM) and age on AOD.

RESULTS

AOD significantly increased with age in both sexes (p < 0.001) with boys exhibiting significantly higher AOD than girls from the age of 14 years (10-11.9 yr: 1.9 vs 1.9 L, 12-13.9 yr: 2.4 vs 2.7 L, 14-15.9 yr: 2.8 vs 4.6 L and 16-17.9 yr: 2.9 vs 5.2 L, in girls and boys respectively, p < 0.001). However, a sex difference was no longer significant when AOD was analysed using an allometric model including age and LBM (p = 0.885). Finally, significant correlations were found between AOD and MPO in boys and girls but with lower evidence in girls (r² = 0.41 vs. 0.89).

CONCLUSION

Non-oxidative energy production increased more extensively in boys than girls from the age of 14 years. Age and LBM accounted for the sexual differentiation of AOD during childhood and adolescence. In addition, AOD was found to be a determinant factor of high-intensity performance, more particularly in boys.

Role of ultra-processed food in fat mass index between 6 and 11 years of age: a cohort study

BACKGROUND

Ultra-processed food consumption and obesity have been highlighted as an important relationship to public health. We aimed to evaluate the association between ultra-processed food consumption and body fat from 6 to 11 years of age.

METHODS

We assessed the association between ultra-processed food consumption (from food frequency questionnaires) and body fat (measured by air displacement plethysmography) between 6 and 11 years of age among participants of the Pelotas-Brazil 2004 Birth Cohort. The NOVA classification was used to classify foods according to the processing degree. Body fat was evaluated relative to the height using fat mass index (FMI). Generalized estimating equations were used to answer the main research question and mediation analyses were run to assess the direct and indirect effect of ultra-processed food in body fat.

RESULTS

At fully adjusted analysis, an increase of 100 g in contribution from ultra-processed food to daily food intake at between 6 and 11 years of age was associated with a gain of 0.14 kg/m² in FMI in the same period; 58% of the total effect of ultra-processed food intake at 6 years (in grams) over the change in FMI from 6 to 11 years was mediated by its calorie content.

CONCLUSIONS

Ultra-processed food consumption was associated with an increase in body fat from childhood to early adolescence, and this association was not just due to the effect of ultra-processed food on calorie content.

Effect of Cross-Sex Hormones on Body Composition, Bone Mineral Density, and Muscle Strength in Trans Women

BACKGROUND

Cross-sex hormone therapy (CHT) changes the physical characteristics of transgender women to match their gender identity and expression. This study aimed to determine the effects of feminizing cross-sex hormones on body composition, bone mineral density (BMD) and muscle strength in transgender women.

METHODS

A prospective observational study assessed 11 participants who underwent feminizing CHT. Dual energy X-ray absorptiometry (DXA), and handgrip strength were measured before CHT and after 6-months of CHT. Fat mass, lean body mass (LBM), and BMD were measured by DXA and handgrip strength was measured by hand-dynamometer.

RESULTS

Regional body fat in the trunk, legs, and gynoid region increased by 18%, 27.4%, and 27.2%, respectively after 6 months of CHT. Total body fat increased by 16.2%, while the fat mass ratio decreased by 7.2%. Although body fat increased, the android/gynoid fat ratio decreased; BMD in the lumbar spine significantly increased by 3.9% (P=0.0051), but changes in the femoral neck (P=0.1969) and total femur (P=0.4769) were not significant. Changes in LBM ranged from -3% (trunk) to -8% (arm region). Right-hand grip strength also significantly decreased by 7.7% (P=0.0467).

CONCLUSIONS

After 6 months of CHT, transgender women showed a general increase in fat mass and a decreased in overall LBM and handgrip strength. Increase in fat mass percentage were more remarkable in gynoid region, leading to a more "female" body fat distribution.

Severe acute malnutrition morphological patterns in children under five

Current methods for infant and child nutritional assessment rely on anthropometric measurements, whose implementation faces technical challenges in low- and middle-income countries. Anthropometry is also limited to linear measurements, ignoring important body shape information related to health. This work proposes the use of 2D geometric morphometric techniques applied to a sample of Senegalese participants aged 6–59 months with an optimal nutritional condition or with severe acute malnutrition to address morphometric variations due to nutritional status. Significant differences in shape and size body changes were described according to nutritional status, resulting age, sex and allometric effect crucial factors to establish nutritional morphological patterns. The constructed discriminant functions exhibited the best classification rates in the left arm. A landmark-based template registering body shape could be useful to both assess acute malnutrition and better understand the morphological patterns that nutritional status promotes in children during their first 5 years of growth and development.

Testosterone therapy masculinizes speech and gender presentation in transgender men

Voice is one of the most noticeably dimorphic traits in humans and plays a central role in gender presentation. Transgender males seeking to align internal identity and external gender expression frequently undergo testosterone (T) therapy to masculinize their voices and other traits. We aimed to determine the importance of changes in vocal masculinity for transgender men and to determine the effectiveness of T therapy at masculinizing three speech parameters: fundamental frequency (i.e., pitch) mean and variation (fo and fo-SD) and estimated vocal tract length (VTL) derived from formant frequencies. Thirty transgender men aged 20 to 40 rated their satisfaction with traits prior to and after T therapy and contributed speech samples and salivary T. Similar-aged cisgender men and women contributed speech samples for comparison. We show that transmen viewed voice change as critical to transition success compared to other masculine traits. However, T therapy may not be sufficient to fully masculinize speech: while fo and fo-SD were largely indistinguishable from cismen, VTL was intermediate between cismen and ciswomen. fo was correlated with salivary T, and VTL associated with T therapy duration. This argues for additional approaches, such as behavior therapy and/or longer duration of hormone therapy, to improve speech transition.

Energy Metrics of Red-Sided Garter Snakes (Thamnophis sirtalis parietalis) Vary with Sex but Not Life-History Stage

Because reproduction is energetically expensive, an organism's energy stores are likely involved in mediating transitions between reproductive and self-maintenance activities. We investigated whether body condition index, adipocyte follicle size, and liver glycogen differ with the life-history transition from reproduction to migration and foraging in red-sided garter snakes (Thamnophis sirtalis parietalis). Females primarily investing in mating behavior located at the den had a significantly higher body condition index than females migrating to summer feeding grounds. The body condition index of male snakes did not differ between snakes located at the den and those migrating to summer feeding grounds. Neither adipocyte follicle area nor liver glycogen stores differed significantly between snakes performing mating activities at the den and those migrating to summer feeding grounds. We did find a sexual dimorphism in that female red-sided garter snakes had significantly larger adipocyte follicles and higher liver glycogen compared with males. Our findings support the across-species phenomenon of females and males displaying a sexual dimorphism in stored energy substrates. Conversely, we did not find evidence to suggest that red-sided garter snakes primarily utilize fatty acids to fuel the initiation of migration, a finding that is not consistent with other long-distance migrators, such as birds. Because we did not find evidence to suggest that stored energy metrics influence the decision to migrate, a physiological mechanism that induces migration in red-sided garter snakes remains elusive.

The relationship of irisin with metabolic syndrome components and insulin secretion and resistance in schoolchildren

Irisin, a novel myokine, is believed to be the crucial factor in converting white adipose tissue to beige adipose tissue. For this paper, we studied the relationship among irisin and components of metabolic syndrome (MetS), and insulin secretion and resistance in schoolchildren of Taiwan.Subjects receiving routine annual health examination at elementary school were enrolled. Demographic data, anthropometry, MetS components, irisin, and insulin secretion and resistance were collected. Subjects were divided into normal, overweight, and obese groups for evaluation of irisin in obesity. Finally, the relationship between irisin and MetS was analyzed.There were 376 children (179 boys and 197 girls), aged 10.3 ± 1.5 years, were enrolled. In boys, irisin levels were not associated with body mass index percentile, body fat, blood pressure, lipid profiles, insulin secretion or resistance. After adjusting for age, the irisin level in boys was negatively related to fasting plasma glucose (FPG) (r = -0.21, P = .006). In girls, after adjusting for age, the irisin levels were positively related only to FPG (r = 1.49, P = .038). In both genders, irisin levels were similar among normal, overweight, and obese groups, and between subjects with and without MetS.The irisin levels were not associated with MetS in either boys or girls. In girls, circulating irisin levels have a nonsignificant declining trend in overweight and obese girls. However, irisin levels were negatively related to FPG in boys and positively related to FPG in girls. The contrary relationship between irisin and FPG in boys and girls needs further exploration.

Optimised anthropometric indices as predictive screening tools for metabolic syndrome in adults: a cross-sectional study

OBJECTIVES

We aimed to evaluate the association between metabolic syndrome (MetS) and two latest optimised indices, waist divided by height ^0.5 (WHT.5R) and body mass index (BMI) multiply by the square root of BMI and waist circumference (BMI√WC), and to comprehensively compare the ability of 10 anthropometric indices to identify MetS, including BMI√WC, WHT.5R, abdominal volume index (AVI), waist-to-height ratio (WHtR), Body Roundness Index (BRI).

DESIGN

Cross-sectional study.

SETTING

Ningxia, China.

PARTICIPANTS

A total of 3860 adults aged 18-88 years from Ningxia, China were recruited by a single stratified cluster random sampling method.

METHODS

ORs and 95% CIs for associations between indices and MetS were calculated using binary logistic regression, and areas under the receiver operating characteristic (ROC) curves (AUCs) were performed to compare their predictive capacity for MetS. All results for men and women were analysed and presented separately.

RESULTS

The highest adjusted ORs for MetS were observed for the following indices: AVI (OR 15.22, 95% CI 10.88 to 21.30), WHT.5R (OR 13.83, 95% CI 9.89 to 19.35) and BMI√WC (OR 12.14, 95% CI 8.79 to 16.76) in men, whereas BRI, WHtR (both OR 14.91, 95% CI 10.39 to 21.4), WHT.5R (OR 14.22, 95% CI 9.96 to 20.29) and AVI (OR 14.03, 95% CI 9.91 to 19.87) in women. In ROC analysis, AVI (AUC: 0.767 for men and 0.749 for women) and WHT.5R (AUC: 0.761 for men and 0.747 for women) showed the highest predictive ability for MetS.

CONCLUSIONS

BMI√WC and WHT.5R were significantly positively associated with MetS, and AVI and WHT.5R could be useful screening tools for identifying MetS in both sexes.

Sex Differences in the Incidence of Obesity-Related Gastrointestinal Cancer

Cancer is the second leading cause of death worldwide, with 9.6 million people estimated to have died of cancer in 2018. Excess body fat deposition is a risk factor for many types of cancer. Men and women exhibit differences in body fat distribution and energy homeostasis regulation. This systematic review aimed to understand why sex disparities in obesity are associated with sex differences in the incidence of gastrointestinal cancers. Cancers of the esophagus, liver, and colon are representative gastrointestinal cancers, and obesity is a convincing risk factor for their development. Numerous epidemiological studies have found sex differences in the incidence of esophageal, liver, and colorectal cancers. We suggest that these sexual disparities are partly explained by the availability of estrogens and other genetic factors regulating inflammation, cell growth, and apoptosis. Sex differences in gut microbiota composition may contribute to differences in the incidence and phenotype of colorectal cancer. To establish successful practices in personalized nutrition and medicine, one should be aware of the sex differences in the pathophysiology and associated mechanisms of cancer development.

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Many captive Asian elephant populations are not self-sustaining, possibly due in part to obesity-related health and reproductive issues. This study investigated relationships between estimated body composition and metabolic function, inflammatory markers, ovarian activity (females only) and physical activity levels in 44 Asian elephants (n=35 females, n=9 males). Deuterium dilution was used to measure total body water from which fat mass (FM) and fat-free mass (FFM) could be derived to estimate body composition. Serum was analyzed for progestagens and estradiol (females only), deuterium, glucose, insulin and amyloid A. Physical activity was assessed by an accelerometer placed on the elephant's front leg for at least 2 days. Relative fat mass (RFM) - the amount of fat relative to body mass - was calculated to take differences in body size between elephants into consideration. Body fat percentage ranged from 2.01% to 24.59%. Male elephants were heavier (P=0.043), with more FFM (P=0.049), but not FM (P>0.999), than females. For all elephants, estimated RFM (r=0.45, P=0.004) was positively correlated with insulin. Distance walked was negatively correlated with age (r=-0.46, P=0.007). When adjusted for FFM and age (P<0.001), non-cycling females had less fat compared with cycling females, such that for every 100 kg increase in FM, the odds of cycling were 3 times higher (P<0.001). More work is needed to determine what an unhealthy amount of fat is for elephants; however, our results suggest higher adiposity may contribute to metabolic perturbations.

What is the most anticipated change induced by treatment using gender-affirming hormones in individuals with gender incongruence?

OBJECTIVES

To identify the most eagerly anticipated change resulting from hormone therapy using gender-affirming hormones for patients with gender incongruence undergoing a clinical trial.

METHODS

Patients diagnosed with gender identity disorders based on the International Classification of Diseases 10th revision classification at three institutions in Japan for whom hormone therapy using gender-affirming hormones was initiated were analyzed. They were asked what the most anticipated change was due to gender-affirming hormone that they had thought of between giving informed consent and the first administration of the drug.

RESULTS

The responders were 336 transgender men who were administered androgens and 48 transgender women who received estrogens. The median age at commencement of hormone therapy was 24 years for transgender men and 28 years for transgender women. For transgender men, the most frequent answer was cessation of menses (52.7%) followed by a deepened voice (32.4%). For transgender women, breast development (35.4%) was the most anticipated change, followed by gynoid fat deposition (29.2%).

CONCLUSIONS

Cessation of menses in transgender men and breast development/gynoid fat deposition in transgender women might represent primary end-points in clinical trials evaluating the efficacy of hormonal treatment in these patients.

[Insulin Difference of Boys and Girls at Birth]

BACKGROUND

Different opinions exist whether girls show higher insulin levels than boys at birth. Insulin values of 863 consecutively born babies whose mothers had no screening for gestational diabetes may provide clarification.

METHOD

Cord serum, measured with a commercially available insulin assay, is therefore retrospectively analyzed for insulin differences in boys and girls.

RESULTS

Girls show higher insulin values than boys (♀6.0/♂5.2 µU/ml). Insulin-sex-difference amounts to 0.8 µU/ml [95% CI 0.3 to 1.3]; p-value 0.003. It is also found in AGA babies, in children of multiparous women, after elective caesarean section and spontaneous vaginal delivery (0.8/1.2/1.7/0.9 µU/ml; p-values 0.003/0.001/0.025/0.006). Girls of multiparous women with macrosomia (LGA/≥ 4000 g) show the highest values of insulin (13.8/13.8 µU/ml) and of insulin-sex-difference (5.5/5.6 µU/ml, p-value 0.001/0.001). This insulin difference can be seen in firstborn babies weighing less than 3640 g, but ≥ 4060 g an inverse insulin sex difference (-5.4 µU/ml; p-value 0.023) with higher insulin values in boys exists (11.3 µU/ml). Children with hyperinsulinaemia (≥20 µU/ml) (17♀, 11♂) show no insulin difference, girls weigh more than boys (154 g, p-value 0.463) and later born babies more (695 g, p-value 0.0001) than firstborns.

CONCLUSION

Higher insulin values of girls have been confirmed. An as yet unknown inverse insulin difference with higher insulin values of firstborn boys with macrosomia has been proved.

Molecular Insulin Actions Are Sexually Dimorphic in Lipid Metabolism

The increment in energy-dense food and low physical activity has contributed to the current obesity pandemic, which is more prevalent in women than in men. Insulin is an anabolic hormone that regulates the metabolism of lipids, carbohydrates, and proteins in adipose tissue, liver, and skeletal muscle. During obesity, nutrient storage capacity is dysregulated due to a reduced insulin action on its target organs, producing insulin resistance, an early marker of metabolic dysfunction. Insulin resistance in adipose tissue is central in metabolic diseases due to the critical role that this tissue plays in energy homeostasis. We focused on sexual dimorphism on the molecular mechanisms of insulin actions and their relationship with the physiology and pathophysiology of adipose tissue. Until recently, most of the physiological and pharmacological studies were done in males without considering sexual dimorphism, which is relevant. There is ample clinical and epidemiological evidence of its contribution to the establishment and progression of metabolic diseases. Sexual dimorphism is a critical and often overlooked factor that should be considered in design of sex-targeted therapeutic strategies and public health policies to address obesity and diabetes.

The Relationship between Serum Insulin-Like Growth Factor-1 Levels and Body Composition Changes after Sleeve Gastrectomy

INTRODUCTION

We previously reported that preoperative serum insulin-like growth factor-1 (IGF-1) is a predictor of total weight loss percentage (%TWL) after laparoscopic sleeve gastrectomy (LSG). IGF-1 may suppress muscle loss after surgery. IGF-1 almost accurately reflects the growth hormone (GH) secretion status, and GH has lipolytic effects. Therefore, IGF-1 may influence both the maintenance of skeletal muscle and the reduction of adipose tissue after LSG. The identification of the relationship between preoperative serum IGF-1 and body composition changes after LSG can help in understanding the pathophysiology of obesity.

METHODS

We retrospectively reviewed 72 patients with obesity who underwent LSG and were followed up for 12 months. We analyzed the relationship between preoperative serum IGF-1 levels and body composition changes after LSG. A multiple regression model was used.

RESULTS

LSG led to a significant reduction in body weight. Both body fat mass and skeletal muscle mass decreased after LSG. Preoperative serum IGF-1 levels significantly correlated with %TWL, changes in skeletal muscle mass, and body fat mass after LSG. The multiple regression model showed that preoperative serum IGF-1 levels were related to decreased body fat mass and maintaining skeletal muscle mass after LSG.

DISCUSSION/CONCLUSION

Preoperative IGF-1 measurement helps predict not only successful weight loss but also decreases body fat mass and maintains skeletal muscle mass after LSG.

Sex Differences in Brown Adipose Tissue Function: Sex Hormones, Glucocorticoids, and Their Crosstalk

Excessive fat accumulation in the body causes overweight and obesity. To date, research has confirmed that there are two types of adipose tissue with opposing functions: lipid-storing white adipose tissue (WAT) and lipid-burning brown adipose tissue (BAT). After the rediscovery of the presence of metabolically active BAT in adults, BAT has received increasing attention especially since activation of BAT is considered a promising way to combat obesity and associated comorbidities. It has become clear that energy homeostasis differs between the sexes, which has a significant impact on the development of pathological conditions such as type 2 diabetes. Sex differences in BAT activity may contribute to this and, therefore, it is important to address the underlying mechanisms that contribute to sex differences in BAT activity. In this review, we discuss the role of sex hormones in the regulation of BAT activity under physiological and some pathological conditions. Given the increasing number of studies suggesting a crosstalk between sex hormones and the hypothalamic-pituitary-adrenal axis in metabolism, we also discuss this crosstalk in relation to sex differences in BAT activity.