Endocrine control of body composition in infancy, childhood, and puberty

Creatine kinase serum levels in children revisited: New reference intervals from a large cohort of healthy children and adolescents

BACKGROUND

Creatine Kinase (CK) has become increasingly important in pediatrics as a commonly used laboratory screening parameter for neuromuscular diseases. Recent research suggests that hyperCKemia in children is not always associated with pathology and can occur due to several reasons. Little is known of various clinical factors that may influence CK throughout child development.

OBJECTIVE

This study aimed to establish reliable age- and sex-specific reference ranges for serum CK levels in healthy infants, children, and adolescents. In addition, the effect of puberty, oral contraceptive (OC) use as well as steroid hormones on CK was examined.

MATERIALS AND METHODS

The data was collected from subjects of the longitudinal population-based "LIFE Child"-cohort between 2011 and 2016 in Leipzig, Germany. 5238 blood samples of 2707 healthy children, aged between 0.14 months and 18 years, were analyzed.

RESULTS

Serum CK levels raised during the first year of life, peaking shortly after age one (P50girls = 2.7 µkat/L, P50boys = 2.90 µkat/L). There was a pronounced difference in the 97.5th percentile between boys and girls during adolescence with its maximum at age 18 (P97.5girls = 5.74 µkat/L, P97.5boys= 14.48 µkat/L). Also, mean CK serum levels were significantly higher in boys (bboys = 0.29, pboys < 0.001). Intake of oral contraceptives (OC), extreme underweight, underweight and obesity revealed a significant inverse correlation with CK serum levels.

CONCLUSION

Age, sex, OC intake and weight status affect serum CK levels, particularly during infancy and puberty. We recommend the use of age- and sex-specific reference values for CK serum levels to assess the clinical relevance of measurements.

Global Prevalence of Overweight and Obesity in Children and Adolescents: A Systematic Review and Meta-Analysis

Importance

Overweight and obesity in childhood and adolescence is a global health issue associated with adverse outcomes throughout the life course.

Objective

To estimate worldwide prevalence of overweight and obesity in children and adolescents from 2000 to 2023 and to assess potential risk factors for and comorbidities of obesity.

Data Sources

MEDLINE, Web of Science, Embase, and Cochrane.

Study Selection

The inclusion criteria were: (1) studies provided adequate information, (2) diagnosis based on body mass index cutoffs proposed by accepted references, (3) studies performed on general population between January 2000 and March 2023, (4) participants were younger than 18 years.

Data Extraction and Synthesis

The current study was performed in accordance with the Meta-analysis of Observational Studies in Epidemiology guidelines. DerSimonian-Laird random-effects model with Free-Tukey double arcsine transformation was used for data analysis. Sensitivity analysis, meta-regression, and subgroup analysis of obesity among children and adolescents were conducted.

Main Outcomes and Measures

Prevalence of overweight and obesity among children and adolescents assessed by World Health Organization, International Obesity Task Force, the US Centers for Disease Control and Prevention, or other national references.

Results

A total of 2033 studies from 154 different countries or regions involving 45 890 555 individuals were included. The overall prevalence of obesity in children and adolescents was 8.5% (95% CI 8.2-8.8). We found that the prevalence varied across countries, ranging from 0.4% (Vanuatu) to 28.4% (Puerto Rico). Higher prevalence of obesity among children and adolescents was reported in countries with Human Development Index scores of 0.8 or greater and high-income countries or regions. Compared to 2000 to 2011, a 1.5-fold increase in the prevalence of obesity was observed in 2012 to 2023. Substantial differences in rates of obesity were noted when stratified by 11 risk factors. Children and adolescents with obesity had a high risk of depression and hypertension. The pooled estimates of overweight and excess weight in children and adolescents were 14.8% (95% CI 14.5-15.1) and 22.2% (95% CI 21.6-22.8), respectively.

Conclusions and Relevance

This study's findings indicated 1 of 5 children or adolescents experienced excess weight and that rates of excess weight varied by regional income and Human Development Index. Excess weight among children and adolescents was associated with a mix of inherent, behavioral, environmental, and sociocultural influences that need the attention and committed intervention of primary care professionals, clinicians, health authorities, and the general public.

Establishing age and gender-specific serum creatinine reference ranges for Thai pediatric population

Accurate assessment of kidney function in children requires age and gender-specific reference ranges for serum creatinine. Traditional reference values, often derived from adult populations and different ethnic backgrounds, may not be suitable for children. This study aims to establish specific reference ranges for serum creatinine in the Thai pediatric population, addressing the gap in localized and age-appropriate diagnostic criteria. This retrospective study analyzed serum creatinine levels from Thai children aged newborn to 18 years, collected from the Laboratory Information System of the Queen Sirikit National Institute of Child Health from January 2017 to December 2021. The Bhattacharya method was employed to establish reference ranges, considering different age groups and genders. The study compared these newly established reference values with international studies, including those of Schlebusch H., Pottel H., and Chuang GT., to validate their relevance and accuracy. A total of 27,642 data entries (15,396 males and 12,246 females) were analyzed. The study established distinct reference ranges for serum creatinine, which varied significantly across different age groups and between genders. These ranges were found to gradually increase with age from 2 months to 18 years. The study also highlighted notable differences in reference values when compared with other ethnic populations. The study successfully establishes tailored reference ranges for serum creatinine in Thai children, providing a valuable tool for more accurate diagnosis and monitoring of kidney health in this demographic. This initiative marks a significant advancement in pediatric nephrology in Thailand and suggests a need for continuous refinement of these ranges and further research in this area.

Sex-specific associations of childhood maltreatment with obesity-related traits - The Study of Health in Pomerania (SHIP)

BACKGROUND

Child maltreatment (CM) is linked to obesity in adulthood. However, sex-differences and direct measurements of body fat have previously been insufficiently considered in this context.

OBJECTIVE

To assess sex-specific associations of CM with anthropometric markers of overweight/obesity and direct measures of body fat.

PARTICIPANTS AND SETTING

Analyses were conducted in 4006 adults from a population-based cohort in Northeastern Germany (SHIP-TREND-0).

METHODS

CM was assessed using the Childhood Trauma Questionnaire (CTQ). Obesity-related traits included anthropometric indicators (i.e., height, weight, body mass index [BMI], waist [WC] and hip circumference [HC], waist-to-hip ratio [WHR], waist-to-height ratio [WHtR]), fat mass (FM) and fat-free mass (FFM) derived from bioelectrical impedance analysis (BIA), and subcutaneous (SAT) and visceral adipose tissue (VAT) ascertained using magnetic resonance imaging (MRI). Sex-stratified linear regression models predicting obesity-related traits from total CTQ scores were adjusted for age and education. Exploratory analyses investigated effects of CTQ subscales on obesity-related traits.

RESULTS

In men, CM was positively associated with WHtR (β = 0.04; p = .030) and VAT (β = 0.02; p = .031) and inversely with body height (β = -0.05; p = .010). In women, CM-exposure was positively associated with body weight (β = 0.07; p = .018), BMI (β = 0.03; p = .013), WC (β = 0.07; p = .005), HC (β = 0.05; p = .046), WHR (β = 0.03; p = .015), WHtR (β = 0.04; p = .006), FM (β = 0.04; p = .006), and SAT (β = 0.06; p = .041). In both sexes, effects were mainly driven by exposure to emotional and physical abuse.

CONCLUSIONS

Results suggest that associations between CM-exposure and obesity-related traits in adulthood are primarily present in women. This may have implications for sex-specific obesity-related cardiometabolic risk after CM.

Sex and Gender Differences on the Impact of Metabolism-Disrupting Chemicals on Obesity: A Systematic Review

Obesity represents an important public health concern, being one of the leading causes of death worldwide. It is a multifactorial disease with many underlying intertwined causes, including genetic, environmental and behavioral factors. Notably, metabolism-disrupting chemicals (MDCs) can alter the set point control of metabolism, affecting the development and function of the adipose tissue. Epidemiological studies have reported associations between human exposure to MDCs and several altered metabolic endpoints. It is also noteworthy that sex and gender represent important risk factors in the development of obesity. Different sex-related biological and physiological characteristics influence individual susceptibility, whereas gender represents a critical component in determining the different exposure scenarios. Although some advancements in the treatment of obesity have been achieved in preclinical and clinical studies, the obesity pandemic continues to increase worldwide. The present study performed a systematic review of recent studies considering the effects of MDCs on obesity, with a specific focus on sex- and gender-related responses. This review highlighted that MDCs could differently affect men and women at different stages of life even though the number of studies evaluating the association between obesity and MDC exposure in relation to sex and gender is still limited. This evidence should urge researchers to carry out studies considering sex and gender differences. This is essential for developing sex-/gender-tailored prevention strategies to improve public health policies and reduce exposure.

Transgender competition in combat sports: Position statement of the Association of ringside physicians

The Association of Ringside Physicians (ARP) is committed to the concept of fair competition. It advocates for two equally skilled and matched athletes to keep bouts fair, competitive, entertaining, and, most importantly, safe for all combatants. Numerous studies have proven that transgender women may have a competitive athletic advantage against otherwise matched cis-gender women. Likewise, transgender men may suffer a competitive disadvantage against cis-gender men. These differences - both anatomic and physiologic - persist despite normalization of sex hormone levels and create disparities in competitive abilities that are not compatible with the spirit of fair competition. More importantly, allowing transgender athletes to compete against cisgender athletes in combat sports, which already involve significant risk of serious injury, unnecessarily raises the risk of injury due to these differences. Hence the ARP does not support transgender athlete competition against cisgender athletes in combat sports.

Phenotyping children and adolescents with obesity using behavioral, psychological, and familial data

OBJECTIVE

This prospective cohort study aimed to empirically derive phenotypes of children and adolescents with overweight and obesity.

METHODS

Latent class analyses using Mplus were carried out in the Growing Up Today Study. Information on participants' weight status, disordered eating behaviors, body image and weight concerns, depressive symptoms, and pubertal timing, as well as and maternal weight status, were included in the latent class analyses, which were stratified by sex. Mixed-effects regression was used to examine associations of the obesity phenotypes with adult weight gain, between age 20 and 35 years, independent of weight at beginning of follow-up and duration of follow-up.

RESULTS

Among the girls, four obesity phenotypes were identified: 1) "early puberty"; 2) "mothers with obesity"; 3) "high weight concerns"; and 4) "mixed." Only three phenotypes were identified among the boys: 1) "high weight concerns"; 2) "mothers with obesity"; and 3) "mixed." Participants who had overweight or obesity in childhood or adolescence gained more weight in young adulthood than their leaner peers, but the patterns of weight gain in young adulthood varied by phenotype of obesity in childhood and adolescence.

CONCLUSIONS

These results support examining risk factors for and treatment outcomes by obesity phenotypes.

The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine

ABSTRACT

Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%-30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.

Long-term reproductive effects of benzo(a)pyrene at environmentally relevant dose on juvenile female rats

Since studies on the reproductive consequences after the exposure to environmentally relevant doses of Benzo(a)pyrene (BaP) during critical stages of development are scarce, this study evaluated female reproductive parameters of adult rats exposed to a low dose of BaP during the juvenile phase. Female rats (Post-natal 21) were treated with BaP (0 or 0.1 µg/kg/day; gavage) for 21 consecutive days. During the treatment, no clinical signs of toxicity were observed. Nevertheless, the ages of vaginal opening and first estrus were anticipated by the BaP-exposure. At the sexual maturity, the juvenile exposure compromised the sexual behavior, as well as the placental efficiency, follicle stimulating hormone levels, placenta histological analysis, and ovarian follicle count. A decrease in erythrocyte, platelet, and lymphocyte counts also was observed in the exposed-females. Moreover, the dose of BaP used in this study was not able to produce estrogenic activity in vivo. These data showed that juvenile BaP-exposure, at environmentally relevant dose, compromised the female reproductive system, possibly by an endocrine deregulation; however, this requires further investigation.

An overview on androgen-mediated actions in skeletal muscle and adipose tissue

Androgens are a class of steroid hormones primarily associated with male sexual development and physiology, but exert pleiotropic effects in either sex. They have a crucial role in various physiological processes, including the regulation of skeletal muscle and adipose tissue homeostasis. The effects of androgens are mainly mediated through the androgen receptor (AR), a ligand-activated nuclear receptor expressed in both tissues. In skeletal muscle, androgens via AR exert a multitude of effects, ranging from increased muscle mass and strength, to the regulation of muscle fiber type composition, contraction and metabolic functions. In adipose tissue, androgens influence several processes including proliferation, fat distribution, and metabolism but they display depot-specific and organism-specific effects which differ in certain context. This review further explores the potential mechanisms underlying androgen-AR signaling in skeletal muscle and adipose tissue. Understanding the roles of androgens and their receptor in skeletal muscle and adipose tissue is essential for elucidating their contributions to physiological processes, disease conditions, and potential therapeutic interventions.

Sex differences and athletic performance. Where do trans individuals fit into sports and athletics based on current research?

There are well known sex differences in parameters of physical fitness/performance due to changes occurring during sexual development. Thus, many sport and athletic events have regulations separating male and female participants. However, the inclusion or exclusion of transgender individuals in athletics has recently received outsized attention despite relatively few cases of transgender athletes. When determining which athletic gender category trans individuals should be permitted to compete in, it is important to understand the level of physical fitness/performance these individuals possess relative to their cisgender counterparts. Unfortunately, there are few studies investigating this topic, and several complications that confound this research. The current review seeks to discuss sex and gender as concepts, review sex differences in fitness/performance and how they develop, and then, consider how current evidence suggests that trans individuals compare to cis individuals. Finally, this review seeks to offer considerations for whether trans individuals should be excluded from sports and athletics, and how future research should proceed to better understand this marginalized population.

Associations of Morphological Changes in Skeletal Muscles of Preschool Children in China Following Physical Activity

PURPOSE

Physical activity (PA) is likely to be the most important modifiable factor in skeletal muscle development. However, the influence of PA on the skeletal muscle of preschool children has not been thoroughly investigated. The main objective of this study was to quantitatively measure PA, and then, to assess whether associations exist between site-specific muscle changes and PA in relation to sex and weight statuses in preschool children aged 3 to 4 years.

METHODS

A total of 86 healthy preschool children, aged 3-4 years, were instructed to wear an accelerometer for seven consecutive days. The number of steps taken daily, and minutes spent in moderate-vigorous PA (MVPA) and total PA (TPA) were recorded. Muscle thickness was measured by B-mode ultrasonography using a 5-18 MHz scanning head. Muscle thickness was measured at seven sites: the lateral forearm, upper arm, abdomen, anterior and posterior thigh, and anterior and posterior lower leg.

RESULTS

There was no significant difference between boys and girls in terms of MVPA and TPA on weekdays and weekends. According to the linear regression models, after adjusting for daylight duration, the muscle of the posterior thigh was significantly positively associated (p < 0.05) with daily steps and MVPA on weekdays for boys and girls, respectively.

CONCLUSIONS

We found that the muscle thickness of the posterior thigh in preschool children was significantly positively associated with PA, as measured by daily steps and MVPA. We suggest that for the overall health and well-being of preschool children, the levels of PA should be maintained and/or increased, and preferably transformed into a regular part of daily living.

Prenatal exposures to mixtures of endocrine disrupting chemicals and sex-specific associations with children's BMI and overweight at 5.5 years of age in the SELMA study

BACKGROUND

Prenatal exposure to mixtures of endocrine disrupting chemicals (EDC) has the potential to disrupt human metabolism. Prenatal periods are especially sensitive as many developmental processes are regulated by hormones. Prenatal exposure to EDCs has inconsistently been associated with children's body mass index (BMI) and obesity. The objective of this study was to investigate if prenatal exposure to a mixture of EDCs was associated with children's BMI and overweight (ISO-BMI ≥ 25) at 5.5 years of age, and if there were sex-specific effects.

METHODS

A total of 1,105 mother-child pairs with complete data on prenatal EDCs concentrations (e.g., phthalates, non-phthalate plasticizers, phenols, PAH, pesticides, PFAS, organochlorine pesticides, and PCBs), children's measured height and weight, and selected covariates in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study were included in this analysis. The mixture effect of EDCs with children's BMI and overweight was assessed using WQS regression with 100 repeated holdouts. A positively associated WQS index with higher BMI and odds of overweight was derived. Models with interaction term and stratified weights by sex was applied in order to evaluate sex-specific associations.

RESULTS

A significant WQS*sex interaction term was identified and associations for boys and girls were in opposite directions. Higher prenatal exposure to a mixture of EDCs was associated with lower BMI (Mean β = -0.19, 95%CI: -0.40, 0.01) and lower odds of overweight (Mean OR = 0.72, 95%CI: 0.48, 1.04) among girls with borderline significance. However, the association among boys did not reach statistical significance. Among girls, the possible chemicals of concern were MEP, 2-OHPH, BPF, BPS, DPP and PFNA.

CONCLUSION

Prenatal exposure to a mixture of EDCs was associated with lower BMI and overweight among girls, and non-significant associations among boys. Chemicals of concern for girls included phthalates, non-phthalate plasticizers, bisphenols, PAHs, and PFAS.

Influence of puberty on relationships between body composition and blood pressure: a cross-sectional study

BACKGROUND

Fat mass (FM) and fat-free mass (FFM) are positively associated with blood pressure (BP) in youth. Yet, how puberty, independent of age, affects these relationships remains unclear. Given puberty may be a crucial period for cardiometabolic health, we examined how pubertal development moderates the associations of FM/FFM with BP.

METHODS

Pubertal development, resting BP, and body composition were assessed in a convenience sample of youth (5.5-17 years). General linear models were conducted to assess if pubertal development moderated the relationships between FM/FFM and systolic/diastolic BP standardized for age, sex, and height (SBPz/DBPz).

RESULTS

Among participants (N = 1405; age: M = 13.3 ± 2.9 years; 65.4% female; 53.2% racial/ethnic minority), FM/FFM were positively associated with SBPz and DBPz (ps ≤ 0.02). Pubertal development moderated the associations between FFM and BPz (ps ≤ 0.01), but not FM (ps > 0.43). For early/mid and late pubertal participants, there were positive associations between FFM and BP (DBPz: βs = 0.10-0.18, ps ≤ 0.01; SBPz: βs = 0.33-0.43, ps < 0.001); however, these relationships were attenuated, especially for prepubertal DBPz (DBPz: β = 0.01, p = 0.91; SBPz: β = 0.24, p = 0.001).

CONCLUSIONS

Puberty moderated the relationships between FFM and SBPz/DBPz in analyses that separately modeled the contributions of age and sex. These data suggest that the FFM-DBPz association may potentially be impacted by increasing sex hormone concentrations during puberty.

IMPACT

Fat mass (FM) and blood pressure (BP) were positively associated throughout puberty. Fat-free mass (FFM) and BP were positively associated throughout puberty; however, puberty moderated the FFM-BP relationship, such that there was a positive relationship in early/mid and late puberty, but the relationship was attenuated for prepubertal children. These findings contribute further insight into physiological and cardiometabolic changes occurring during puberty. Changes in hormone concentrations may explain the impact puberty has on the FFM-BP relationship. Understanding predictors of BP are important as childhood BP is associated with future cardiometabolic outcomes.

Physical fitness of primary school children differs depending on their timing of school enrollment

Previous research has shown that children who were enrolled to school according to the legal key date (i.e., keyage children, between eight and nine years in third grade) exhibited a linear physical fitness development in the ninth year of life. In contrast, children who were enrolled with a delay (i.e., older-than-keyage children [OTK], between nine and ten years in third grade) exhibited a lower physical fitness compared to what would be expected for their age. In these studies, cross-sectional age differences within third grade and timing of school enrollment were confounded. The present study investigated the longitudinal development of keyage and OTK children from third to fifth grade. This design also afforded a comparison of the two groups at the same average chronological age, that is a dissociation of the effects of timing of school enrollment and age. We tested six physical fitness components: cardiorespiratory endurance, coordination, speed, power of lower and upper limbs, and static balance. 1502 children (i.e., 1206 keyage and 296 OTK children) from 35 schools were tested in third, fourth, and fifth grade. Except for cardiorespiratory endurance, both groups developed from third to fourth and from fourth to fifth grade and keyage children outperformed OTK children at the average ages of 9.5 or 10.5 years. For cardiorespiratory endurance, there was no significant gain from fourth to fifth grade and keyage and OTK children did not differ significantly at 10.5 years of age. One reason for a delayed school enrollment could be that a child is (or is perceived as) biologically younger than their chronological age at the school entry examination, implying a negative correlation between chronological and biological age for OTK children. Indeed, a simple reflection of chronological age brought the developmental rate of the chronologically youngest OTK children in line with the developmental rate observed for keyage children, but did not eliminate all differences. The mapping of chronological and biological age of OTK children and other possible reasons for lower physical fitness of OTK children remain a task for future research.

Encapsulated Allografts Preclude Host Sensitization and Promote Ovarian Endocrine Function in Ovariectomized Young Rhesus Monkeys and Sensitized Mice

Transplantation of allogeneic donor ovarian tissue holds great potential for female cancer survivors who often experience premature ovarian insufficiency. To avoid complications associated with immune suppression and to protect transplanted ovarian allografts from immune-mediated injury, we have developed an immunoisolating hydrogel-based capsule that supports the function of ovarian allografts without triggering an immune response. Encapsulated ovarian allografts implanted in naïve ovariectomized BALB/c mice responded to the circulating gonadotropins and maintained function for 4 months, as evident by regular estrous cycles and the presence of antral follicles in the retrieved grafts. In contrast to non-encapsulated controls, repeated implantations of encapsulated mouse ovarian allografts did not sensitize naïve BALB/c mice, which was confirmed with undetectable levels of alloantibodies. Further, encapsulated allografts implanted in hosts previously sensitized by the implantation of non-encapsulated allografts restored estrous cycles similarly to our results in naïve recipients. Next, we tested the translational potential and efficiency of the immune-isolating capsule in a rhesus monkey model by implanting encapsulated ovarian auto- and allografts in young ovariectomized animals. The encapsulated ovarian grafts survived and restored basal levels of urinary estrone conjugate and pregnanediol 3-glucuronide during the 4- and 5-month observation periods. We demonstrate, for the first time, that encapsulated ovarian allografts functioned for months in young rhesus monkeys and sensitized mice, while the immunoisolating capsule prevented sensitization and protected the allograft from rejection.

Stress and Growth in Children and Adolescents

The infantile, childhood, and adolescent periods of growth and development also represent times of increased vulnerability to stressors. Growth velocity in each period is dependent on the interplay of genetic, environmental, dietary, socioeconomic, developmental, behavioral, nutritional, metabolic, biochemical, and hormonal factors. A stressor may impact growth directly through modulation of the growth hormone axis or indirectly through other factors. The adaptive response to stressors culminates in behavioral, physiological, and biochemical responses which together support survival and conservation of energy. The immediate response involves activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. The time-limited stress response is at once antigrowth, antireproductive, and catabolic with no lasting adverse consequences. However, chronic activation of the stress system and hypercortisolism have consequential negative impacts on growth, thyroid function, reproduction-puberty, and metabolism. High cortisol suppresses growth hormone-insulin-like growth factor 1, hypothalamic-pituitary-gonadal, and thyroid axes and has been reported to be responsible for an increase in visceral adiposity, a decrease in lean mass, suppression of osteoblastic activity with risk of osteoporosis, and induction of insulin resistance. Early-life adversities, emotional or physical, have been associated with long-term negative physical and mental health outcomes. Existing models of chronic stress corroborate that early-life adversities can affect growth and have consequences in other aspects of well-being throughout the lifespan. Targeted interventions to reduce stress during infancy, childhood, and adolescence can have far-reaching benefits to long-term health as well as attaining adequate growth. In this review, we describe the neuroendocrinology of the stress response, the factors influencing growth, and the impact of chronic stress on growth during critical periods of infancy, childhood, and puberty with particular reference to growth, thyroid, and gonadal axis.

Management of Growth Disorders in Puberty: GH, GnRHa, and Aromatase Inhibitors: A Clinical Review

Pubertal children with significant growth retardation represent a considerable therapeutic challenge. In growth hormone (GH) deficiency, and in those without identifiable pathologies (idiopathic short stature), the impact of using GH is significantly hindered by the relentless tempo of bone age acceleration caused by sex steroids, limiting time available for growth. Estrogen principally modulates epiphyseal fusion in females and males. GH production rates and growth velocity more than double during puberty, and high-dose GH use has shown dose-dependent increases in linear growth, but also can raise insulin-like growth factor I concentrations supraphysiologically, and increase treatment costs. Gonadotropin-releasing hormone analogs (GnRHas) suppress physiologic puberty, and when used in combination with GH can meaningfully increase height potential in males and females while rendering adolescents temporarily hypogonadal at a critical time in development. Aromatase inhibitors (AIs) block androgen to estrogen conversion, slowing down growth plate fusion, while allowing normal virilization in males and stimulating longitudinal bone growth via androgen receptor effects on the growth plate. Here, we review the physiology of pubertal growth, estrogen and androgen action on the epiphyses, and the therapeutic impact of GH, alone and in combination with GnRHa and with AIs. The pharmacology of potent oral AIs, and pivotal work on their efficacy and safety in children is also reviewed. Time-limited use of AIs is a viable alternative to promote growth in pubertal males, particularly combined with GH. Use of targeted growth-promoting therapies in adolescence must consider the impact of sex steroids on growth plate fusion, and treatment should be individualized.

Physiologic and Behavioral Correlates of Energy Intake in Emerging Adulthood: Cross-Sectional Analysis of the RIGHT Track Health Study

BACKGROUND

Consistent findings have reported that FFM is associated with EI. However, conjoint assessments of physiologic (body composition, fasting serum leptin) and behavioral [eating behaviors and physical activity (PA)] correlates of EI during emerging adulthood have not been examined.

OBJECTIVES

We assessed associations between physiologic and behavioral correlates of EI within the context of one another in emerging adults (18-28 years old). We also assessed these associations in a subsample after the removal of probable EI underreporters.

METHODS

Cross-sectional data from 244 emerging adults (age = 19.6 ± 1.4 y; BMI = 26.4 ± 6.6 kg/m2; 56.6% female) from the RIGHT Track Health study were used. Measures included body composition (BOD POD), eating behaviors (Three-Factor Eating Questionnaire), objective and subjective PA (accelerometer-derived total activity counts and Godin-Shephard Leisure-Time Exercise Questionnaire), fasting serum leptin, and EI (three 24-hour dietary recalls). Correlates independently associated with EI were entered into a backward stepwise linear regression model. Correlates that met the criteria of P < 0.05 were retained. Analyses were repeated in a subsample after removing probable EI underreporters (n = 48). Effect modification by sex (male and female) and BMI (BMI < 25 kg/m2, BMI ≥ 25 kg/m2) categories was also assessed.

RESULTS

In the full sample, FFM (β: 18.4; 95% CI: 9.9, 26.8), leptin (β: -84.8; 95% CI: -154.3, -15.4), dietary restraint (β: -35.2; 95% CI: -59.1, -11.3), and subjective PA (β: 2.5; 95% CI: 0.04, 4.9) were significantly associated with EI. After the removal of probable underreporters, only FFM remained significantly associated with EI (β: 43.9; 95% CI: 27.2, 60.6). No evidence of effect modification by sex or BMI categories was noted.

CONCLUSIONS

Although physiologic and behavioral correlates were associated with EI in the full sample, only FFM remained a robust correlate of EI in a subsample of emerging adults after removing probable EI underreporters.

The influence of growth hormone on pediatric body composition: A systematic review

BACKGROUND

Growth hormone (GH) affects metabolism and regulates growth in childhood. The most prominent feature of GH deficiency (GHD) in children is diminished height velocity that eventually leads to short stature. In adult-onset GHD, lean body mass (LBM) is reduced, and visceral fat mass (FM) increased. Beneficial effects of GH treatment on body composition in adults with GHD, including an increase in muscle mass and a decrease in FM, are well established. Relatively few studies have investigated the effects of GH treatment on the body composition of pediatric patients with idiopathic or hypothalamic-pituitary disease-associated GH deficiency. This systematic review aimed to summarize available evidence relating to the effects of GH treatment on body composition in children with GHD.

METHODS

The PubMed, Science Direct, Cochrane Trials, and Embase databases, were searched with keywords including "GH", "body composition", "children", and "growth hormone" for English-language articles, published between January 1999 and March 2021. Two reviewers independently evaluated the search results and identified studies for inclusion based on the following criteria: participants had a confirmed diagnosis of GHD (as defined in each study); participants were pediatric patients who were receiving GH or had stopped GH treatment, regardless of whether they were pre- or post-pubertal; the intervention was recombinant human GH (rhGH; somatropin); and outcomes included changes in body composition during or after stopping GH therapy. Data extracted from each study included study quality, study sample characteristics, study interventions, and body composition. Data on fat-free mass and LBM were combined into a single category of LBM.

RESULTS

Sixteen studies reporting changes in body composition (i.e., FM and LBM) associated with GH treatment in children with GHD were identified and included in the review. Collectively, these studies demonstrated that FM decreased, and LBM increased in response to GH replacement therapy.

CONCLUSION

Despite study limitations (i.e., potential effects of diet and physical activity were not considered), we concluded that a periodic body composition assessment is required to ensure that a satisfactory body composition is achieved during GH replacement therapy in children with GHD.

Nutrition in school-age children: a rationale for revisiting priorities

Middle childhood and early adolescence have received disproportionately low levels of scientific attention relative to other life stages, especially as related to nutrition and health. This is partly due to the justified emphasis on the first 1000 days of life, and the idea that early deficits and consequences may not be fully reversible. In addition, these stages of life may superficially appear less "eventful" than infancy or late adolescence. Finally, there has been historical ambiguity and inconsistency in terminology, depending on whether viewing "childhood" through physiologic, social, legal, or other lenses. Nevertheless, this age bracket, which encompasses most of the primary education and basic schooling years for most individuals, is marked by significant changes, inflection points, and sexually driven divergence in somatic and brain growth and development trajectories. These constitute transformative changes, and thus middle childhood and early adolescence represents a major and last opportunity to influence long-term health and productivity. This review highlights the specificities of growth and development in school age, with a focus on middle childhood and early adolescence (5 years-15 years of age, for the purposes of this review), the role of nutrition, the short- and long-term consequences of inadequate nutrition, and the current global status of nutrition in this age group. Adequate attention and emphasis on nutrition in the school-age years is critical: (a) for maintaining an adequate course of somatic and cognitive development, (b) for taking advantage of this last major opportunity to correct deficits of undernutrition and "catch-up" to normal life course development, and (c) for addressing the nutritional inadequacies and mitigating the longer-term consequences of overnutrition. This review summarizes and provides a rationale for prioritizing nutrition in school-age children, and for the need to revisit priorities and focus on this part of the life cycle to maximize individuals' potential and their contribution to society.

[Associations between early onset of puberty and obesity types in children: Based on both the cross-sectional study and cohort study]

OBJECTIVE

To explore and analyze the relationship between early onset of puberty and different types of obesity in children, by combining large sample cross-sectional survey data with long-term longitudinal cohort data, so as to provide clues for further clarifying the health hazards of early onset of puberty and obesity prevention and control.

METHODS

The research data were from the cross-sectional survey data of seven provinces(autonomous regions, municipalities) in China and the cohort data of adolescent development in Xiamen. The study first found the association between early onset of puberty and obesity by Logistic regression on the cross-sectional data, and then used Poisson regression to analyze the association between early puberty initiation and various types of obesity risk.

RESULTS

In the study, 43 137 and 1 266 children were included in the cross-sectional survey and cohort survey respectively. The cross-sectional study found that among the girls aged 10-13 years, compared with the girls of the same age who did not start puberty, the body mass index (BMI)-Z score of the girls in the puberty start group was 0.5-0.8 higher, and the waist circumference Z score was 0.4-0.7 higher, and the risk of various types of obesity was higher. At the same time, the early onset of puberty was positively correlated with simple obesity, central obesity and compound obesity, the OR (95%CI) were 1.86 (1.42-2.44), 1.95 (1.65-2.32) and 1.86 (1.41-2.45), respectively. No significant association was found in boys. According to the cohort data, in girls, the risk of simple obesity was 6.00 times [RR (95%CI): 6.00 (1.07-33.60)], the risk of central obesity was 3.30 times [RR (95%CI): 3.30 (1.22-8.92)], and the risk of compound obesity was 5.76 times [RR (95%CI): 5.76 (1.03-32.30)], compared with the group without early puberty initiation, while no association between early puberty initiation and obesity was found in boys.

CONCLUSION

Based on the cross-sectional survey and longitudinal cohort survey, it is confirmed that the early onset of puberty in girls may increase the risk of simple obesity, central obesity and compound obesity, while there is no significant correlation between puberty onset and obesity in boys.

Lead Exposure in Infancy and Subsequent Growth in Beninese Children

Studies suggest that elevated postnatal blood lead levels (BLLs) are negatively associated with child growth. This study aimed to investigate the associations of childhood BLLs at age one year and growth outcomes at age six years (n = 661) in a cohort of children in Allada, Benin. The growth outcomes studied are weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ), BMI-for-age Z-score (BMIZ), weight-for-height Z-score (WHZ), head circumference (HC), growth velocities, underweight, stunting, and wasting. Multivariable regression models examined the associations between BLLs and growth outcomes, with adjustment for potential confounders. The geometric mean BLLs was 59.3 μg/L and 82% of children had BLLs >35 μg/L at the age of 12.8 months. After adjusting for confounding factors, no overall association was found between BLL quartiles and HAZ, WAZ, BMIZ, WHZ, growth velocities, wasting, and underweight. However, boys in the highest quartile had a 1.02 cm lower HC (95% CI: [−1.81, −0.24]) as compared to the lowest quartile. Furthermore, an increased odds of being stunted was observed in children in the highest quartile of exposure compared to the first (OR: 2.43; 95% CI: [1.11−5.33]) which remained statistically significant only among girls in sex-specific strata. Blood lead was found to be associated with an increased risk of childhood stunting and a lower head circumference in a resource-limited setting.

Sex-Specific Effect of Obesity on Epiblepharon in Different Age Groups: A Case-Control Study

Obesity has been regarded as a risk factor for several ocular diseases. This study aims to investigate the age- and sex-specific relationship between epiblepharon and obesity in children. A retrospective case-control study was conducted using the Chang Gung Research Database. Children ≤ 18 years of age with epiblepharon were identified from 1 January 2009 to 31 December 2019. Children were classified into three groups: normal, overweight and obese groups. A total of 513 patients and 1026 controls (57.7% males) aged 1 to 18 matched by sex and age were included in the analysis. The median body mass index (BMI) of children with epiblepharon was significantly higher than that of children without epiblepharon (p < 0.001). In the subgroup analysis, among boys aged 4 to 9 years, the BMI in boys with epiblepharon was significantly higher than that in boys without epiblepharon (p < 0.05) and the risk of epiblepahron in overweight/obese boys was significantly higher than in non-overweight boys (OR = 1.74, 95% CI = 1.07-2.82 for age 4 to 6; OR = 3.06, 95% CI = 1.56-6.03 for age 7 to 9). On the other hand, among girls aged 13 to 18 years, the BMI in adolescent girls with epiblepharon was significantly higher than that in the control group (p < 0.05) and overweight/obese girls had a statistically higher risk of persistent epiblepharon than non-overweight girls (OR = 3.70, 95% CI = 1.38-9.97). The association between obesity and epiblepharon varies in strength according to age in a sex-specific manner.

Associations between body mass index in different childhood age periods and hyperuricemia in young adulthood: the China Health and Nutrition Survey cohort study

BACKGROUND

Few studies have evaluated the specific age period in childhood when the association of body mass index with adult hyperuricemia begins to be operative. This study aimed to examine the associations between body mass index in different childhood age periods and the risk of adult hyperuricemia in China.

METHODS

The study cohort from the China Health and Nutrition Survey included 676 participants who were aged ≥ 18 years and had data on uric acid in 2009 with at least one measurement of body mass index in childhood surveys before 2009. There were 357, 365, 358, 427, and 432 observations in childhood age groups of ≤ 5 years, 6-9 years, 10-12 years, 13-15 years, and 16-18 years, respectively. Body mass index Z score was calculated based on 2000 Center for Disease Control and Prevention growth charts for the United States.

RESULTS

Childhood body mass index Z scores measured at age ≤ 5 years, 6-9 years, 10-12 years, and 13-15 years had no statistical association with adult uric acid. In comparison, childhood body mass index Z scores measured at age 16-18 years were significantly associated with adult uric acid (β = 11.539, P = 0.007), and the strength of association was stronger in girls (β = 18.565, P = 0.002) than in boys (β = 9.209, P = 0.087). In addition, childhood body mass index Z scores measured at age 16-18 years were significantly associated with an increased risk of adult hyperuricemia (odds ratio = 1.323, 95% confidence interval = 1.003-1.746, P = 0.048), but not for other age groups.

CONCLUSION

The association between childhood body mass index and young adulthood hyperuricemia was influenced by childhood age.

Early rapid weight gain, parental body mass index and the association with an increased waist-to-height ratio at 5 years of age

Background/Objectives

Obesity-related adverse health consequences are closely associated with abdominal obesity. Risk factors for overweight and obesity have been studied but there is a lack of information regarding risk factors for abdominal obesity, especially in the preschool population. The aim of the present study was to examine early life risk factors for an increased waist-to-height ratio (WHtR) in children at five years of age and, in addition, to investigate if these risk factors also were associated with overweight or obesity.

Subjects/Methods

The study population comprised 1,540 children from a population-based longitudinal birth cohort study that included 2,666 Swedish children. The children were included if they had complete growth data for the analyses used in this study. Children were classified as having WHtR standard deviation scores (SDS) ≥ 1 or < 1 at five years of age, according to Swedish reference values, and as having body mass index standard deviation scores (BMI_SDS) for overweight/obesity, or normal weight/underweight according to the International Obesity Task Force criteria. Associations between child-related, socioeconomic status-related, parental health-related and nutrition- and feeding practice-related factors during the first two years and a WHtR_{SDS ≥} 1 or a BMI_SDS for overweight/obesity at five years were investigated with logistic regression analyses.

Results

At five years of age, 15% of the children had WHtR_{SDS ≥} 1 and 11% had overweight or obesity. In multivariable analyses, rapid weight gain (RWG) during 0–6 months (OR: 1.90, 95% CI: 1.23–2.95, p = 0.004), maternal pre-pregnancy BMI (1.06, 1.01–1.11, p = 0.019) and paternal BMI (1.11, 1.01–1.21, p = 0.028) were associated with WHtR_{SDS ≥} 1. RWG during 0–6 months (2.53, 1.53–4.20, p<0.001), 6–12 months (2.82, 1.37–5.79, p = 0.005), and maternal pre-pregnancy BMI (1.11, 1.06–1.17, p<0.001) were associated with overweight or obesity.

Conclusions

Early risk factors, including rapid weight gain, are associated with increased WHtR_SDS and overweight or obesity at 5 years of age. Preventive interventions should target early RWG and parental overweight and obesity.

Do dietary patterns differ with video game usage in college men?

Objective: To assess differences in dietary quality among college men reporting high, moderate, and non-video game usage. Participants: College men aged 18-24. Methods: Cross-sectional data were collected between 2012 and 2020. Participants (n = 1259) were categorized according to self-reported video game usage: non-users (NVG), <1 h/day (MVG), and ≥1 h/day (HVG). ANCOVA identified group differences in nutrient intake from 3-day food records. Results: College men reported 30% NVG, 39% MVG, and 31% HVG. Higher saturated fat (30.2 ± 0.4 g and 30.1 ± 0.3 g, vs. 28.5 ± 0.4 g, p < .01, p < .01) and lower fruit/vegetable intake (3.00 ± 0.1 cups and 2.91 ± 0.1 cups, vs. 3.45 ± 0.1 cups, p < .00, p < .00) was observed in HVG and MVG vs. NVG. Higher discretionary calories (750 ± 13 kcals, vs. 686 ± 13 kcals, p < .00) in HVG and sodium (3922 ± 44 mg, vs. 3860 ± 50 mg, p < .02) in MVG were reported vs. NVG. Conclusion: Video game usage was associated with higher saturated fat, sodium, discretionary calories, and lower F/V intake in college men.

Plasma transthyretin is a nutritional biomarker in human morbidities

Transthyretin (TTR) is a small liver-secreted plasma protein that shows close correlations with changes in lean body mass (LBM) during the entire human lifespan and agglomerates the bulk of nitrogen (N)-containing substrates, hence constituting the cornerstone of body building. Amino acids (AAs) dietary restriction causes inhibition of TTR production and impairs the accretion of LBM reserves. Inflammatory disorders result in cytokine-induced abrogation of TTR synthesis and urinary leakage of nitrogenous catabolites. Taken together, the data indicate that malnutrition and inflammation may similarly suppress the production of TTR through distinct and unrelated pathophysiological mechanisms while operating in concert to downsize LBM stores. The hepatic synthesis of TTR integrates both machineries, acting as a marker of reduced LBM resources still available for defense and repair processes. TTR operates as a universal surrogate analyte that allows for the grading of residual LBM capacity to reflect disease burden. Measurement of TTR is a simple, rapid, and inexpensive micro-method that may be reproduced on a daily basis, hence ideally suited for the follow-up of the most intricated clinical situations and as a reliable predictor of any morbidity outcome.

Reproductive life histories: can incremental dentine isotope analysis identify pubertal growth, pregnancy and lactation?

BACKGROUND

There are few reliable osteological indicators to detect parity or infer puberty in skeletal remains. Nitrogen (δ¹⁵N) and stable carbon (δ¹³C) isotope ratios in human tissues can be affected by metabolically unbalanced states engendered by pregnancy or rapid growth, offering potential biomarkers.

AIM

This pilot study explores the potential of incremental dentine-collagen isotope ratio analysis to identify puberty and gestation.

SUBJECTS AND METHODS

Incremental dentine δ¹⁵N and δ¹³C profiles were produced by analysing third molars extracted as part of dental treatment of 10 individuals living in Sudan. Demographic and anthropometric data at the time of tooth extraction was available. Medical histories were unknown.

RESULTS

Isotopic signatures potentially related to pubertal growth, with an average δ¹⁵N reduction of 0.78 ± 0.29‰, are indicated. Six isotopic signals suggestive of pregnancy, with an average δ¹⁵N decrease of 0.48 ± 0.22‰, are also observed. The timing, speed and amplitude of post-partum δ¹⁵N patterns seemingly infer infant feeding practices and maternal nutritional status.

CONCLUSION

This pilot study highlights the potential of incremental dentine isotope analysis for the reconstruction of early reproductive histories in skeletal remains. However, controlled studies with a larger human cohort are needed to validate these findings, establish isotopic signals linked to puberty and lactation, and improve chronology accuracy.

Relationship between height age, bone age and chronological age in normal children in the context of nutritional and pubertal status

INTRODUCTION

Bone age (BA) is a quantitative determination of skeletal maturation. The role of puberty in variations in BA is poorly understood as hypothalamic-pituitary-gonadal (HPG) axis maturation and skeletal maturation are regulated in parallel but independently by multiple different factors. In countries like India where there is rapid nutrition transition and increase in prevalence of obesity, their impact on height and BA is not well understood.

OBJECTIVES

To study if in 2-17 year old healthy children, the difference between chronological age (CA), height age (HA) and BA is less than 1 year on either side of the chronological age and to assess relationship of BA with height, weight and BMI with special reference to gender and puberty.

METHODS

This cross-sectional study included 804 preschool/school-going Indian children. Anthropometric measurements and pubertal assessments were performed using standard protocols and were converted to age and sex standardized z-scores using Indian references while BA was estimated by Tanner-Whitehouse (TW3) method. p<0.05 was considered statistically significant.

RESULTS

The mean age and gender standardized z-scores for height, weight, body mass index (BMI) and BA were -0.3 ± 0.7, -0.7 ± 0.8, -0.1 ± 1.0, and -0.2 ± 0.9 respectively. HA was more delayed in girls while BA was more delayed in boys. The mean BA z-score increased with increasing BMI. After the onset of puberty, there was higher increment in BA in girls and HA in boys (p<0.05).

CONCLUSIONS

HA, BA and CA were tightly correlated in healthy Indian children with a significant role of nutritional status and puberty in causing variation in the same.

Prognostic impact of sarcopenia in children with cancer: a focus on the psoas muscle area (PMA) imaging in the clinical practice

Skeletal muscle plays a crucial part in the metabolic and inflammatory response. "Sarcopenia", defined as a pathological condition of reduced strength, quantity and quality of skeletal muscle mass, may often develop in the young age as the secondary consequence of a systemic inflammatory illness, like cancer. In children with cancer, sarcopenia is a common finding, playing a negative role in their prognosis. However, its prevalence in clinical practice is underestimated. Moreover, several pre- and post-natal factors may influence skeletal muscle development in childhood, making the issue more complex. Given the frequent use of radiological imaging in clinical practice, prompt analysis of body composition is feasible and able to detect the presence of reduced fat-free mass (FFM) among pediatric patients with cancer. We discuss the recent advances in the study of body composition in children with cancer, dissecting the role of the psoas muscle area (PMA) measure, obtained from computerized tomography (CT) or magnetic resonance images (MRI) as a marker of sarcopenia in this setting. Since age and sex-specific percentile curves for PMA and a PMA z-scores calculator are available online, such a tool may be useful to simply detect and treat sarcopenia and its consequences in childhood cancer.

Cardiometabolic Health After Pediatric Cancer Treatment: Adolescents Are More Affected than Children

This cross-sectional study aimed at comparing the cardiometabolic (CM) health of children and adolescents and identifying factors associated with CM complications shortly after cancer treatment. Cancer-related characteristics, blood pressure (BP), anthropometry, and biochemical parameters were collected in 80 patients (56.3% female, mean age: 11.8 years; range: 4.5 - 21.0) a mean of 1.4 years following therapy completion. Compared to children, adolescents had higher mean z-score of insulin (-0.47 vs. 0.20; P = 0.01), HOMA-IR (-0.40 vs. 0.25; P = 0.02), waist-to-height ratio (0.36 vs. 0.84; P = 0.01), subscapular skinfold thickness (-0.19 vs. 0.47; P = 0.02), total body fat (-1.43 vs. 0.26; P < 0.01), and lower mean z-score of HDL-C (0.07 vs. -0.53; P < 0.01). Adolescents were more likely to have high BP (42% vs. 15%; P < 0.01), dyslipidemia (64% vs. 15%; P < 0.001), and cumulating ≥ 2 CM complications (42% vs. 2%; P < 0.001) than children. Adiposity indices (z-scores) were associated with high BP [odds ratio (OR) ranging from 2.11 to 4.09] and dyslipidemia (OR ranging from 2.06 to 4.34). These results suggest that adolescents have a worse CM profile than children shortly after therapy and that adiposity parameters are associated with CM complications, highliting the importance to develop intervention strategies targeting this population.

Influence of Maturity Status on Kinanthropometric and Physical Fitness Variables in Adolescent Female Volleyball Players

The aim of this research was to analyze differences in kinanthropometric characteristics and physical performance in relation to maturity status, as well as to determine if age, maturity offset or kinanthropometric variables could predict better performance in physical fitness tests. A total of 152 female volleyball players (14.16 ± 1.25 years old) underwent a kinanthropometric assessment, followed by a physical fitness assessment composed of different tests. The age at peak height velocity (APHV) was calculated, and the sample was divided according to biological maturation into three groups. Significant differences were observed in kinanthropometric variables (p < 0.001–0.026), with early maturers showing higher values. Age, body mass, Cormic index, relative arm span, ∑8 skinfolds, fat mass, corrected arm and thigh girths, muscle mass and biacromial and biiliocristal breadths were the variables that best predicted performance in the physical tests (p < 0.001–0.024). The more mature players showed higher values in most of the kinanthropometric variables, with the more remarkable differences being in body mass, height, arm span and sitting height, and those related to adiposity and absolute body composition, and with structural variables being the most influential on the physical tests. Age had a determinant influence on the differences found between groups in strength and power-related test performance.

Healthy Long-Lived Human Beings—Working on Life Stages to Break the Limitation of Human Lifespans

The human lifespan has been increasing but will soon reach a plateau. A new direction based on the principal law of lifespan (PLOSP) may enable the human lifespan to be extremely healthy and long by the proper manipulation of the well-defined growing stages of the lifespan. The lifespan of creatures on earth from a single cell to animals can be elongated at different life stages including prenatal development, body growth, reproductivity, and aging. Each life stage has its own specific physiological and metabolic characteristics. Each life stage can be lengthened by either slowing its processes or continuously maintaining the activities of its function. Unfortunately, the current biomedical research on the extension of lifespans has mainly focused on the aging stage. Recognizing and clearly defining the periods of transition and the boundaries of life stages are essential for achieving the goal of long-lived healthy humans based on the PLOSP. The biomedical measures and pharmacological treatments for the extension of lifespans is life-stage-specific. The PLOSP can be tested with modified studies on longevity with a variety of technologies such as castration and ovariectomy. Sex differences in biological functions and the sequential order of the life stages requires different approaches for females and males.

Match or mismatch between chronotype and sleep-wake cycle and their association with lean body mass gain among male high-school baseball players

For athletes, it is important to acquire lean body mass (LBM) involving the skeletal muscle mass during their growth periods; however, the influence of chronotype on LBM gain remains unclear. We therefore aimed to investigate whether chronotype, sleep-wake cycle on weekdays (SWC-W), and their interaction contribute to LBM gain among adolescent male athletes in a 4-month intervention study. The participants were 45 male high-school baseball players. The intervention, including exercise menu (running and muscle strength training) and nutritional education, was conducted during a 4-month period of season-off training. The chronotype, body composition, lifestyle, and dietary intake were investigated before intervention (baseline) and after 4 months. Among the participants [Morningness (n = 14), Eveningness (n = 15), Intermediate (n = 16); ME score based on the Morningness/Eveningness Scale for Children (MES-C)], the midpoint of sleep on weekdays (MSW) was calculated in the "Morningness" and "Eveningness" participants, respectively. They were divided into 4 groups based on a match/mismatch with the chronotype: Type M-match (n = 8), Type M-mismatch (n = 6), Type E-match (n = 7), and Type E-mismatch (n = 8) groups. The data were compared among the 4 groups. Moreover, multiple regression analysis was conducted using an increase (kg) LBM gain as a response variable. When comparing the data between the "Morningness" and "Eveningness" participants, there were no differences in nutrient intake, the duration of training, or each parameter of body composition (per body weight) at baseline or after 4 months. There were also no differences in the rates of change in the body weight or each parameter of body composition. In groups in which the chronotype was consistent with the SWC-W (the Type M-match and Type E-match groups), the LBM gain were slightly greater than in the Type M-mismatch and Type E-mismatch groups (Type M-match: 3.5 ± 2.0 kg, Type M-mismatch: 1.6 ± 1.7 kg, Type E-match: 3.4 ± 2.2 kg, and Type E-mismatch: 1.2 ± 1.8 kg, p = .057). Multiple regression analysis revealed that an extent of the LBM gain was associated with a match between the chronotype and SWC-W (ß = 0.37, p = .030), independent of a long duration of training (ß = 0.52, p = .004). The results suggested that training-related LBM gain is associated with interactions between the chronotype and SWC-W in adolescent male athletes.Abbreviations: LBM: Lean body mass; SWC-W: Sleep-wake cycle on weekdays; ME score: Morningness-eveningness score; MES-C: Morningness/Eveningness Scale for Children; MSW: Midpoint of sleep on weekdays; MSF: Midpoint of sleep on free days; MSFsc: Midpoint of sleep on free days corrected for sleep debt accumulated through weekdays.

Nutrition in adolescent growth and development

During adolescence, growth and development are transformative and have profound consequences on an individual's health in later life, as well as the health of any potential children. The current generation of adolescents is growing up at a time of unprecedented change in food environments, whereby nutritional problems of micronutrient deficiency and food insecurity persist, and overweight and obesity are burgeoning. In a context of pervasive policy neglect, research on nutrition during adolescence specifically has been underinvested, compared with such research in other age groups, which has inhibited the development of adolescent-responsive nutritional policies. One consequence has been the absence of an integrated perspective on adolescent growth and development, and the role that nutrition plays. Through late childhood and early adolescence, nutrition has a formative role in the timing and pattern of puberty, with consequences for adult height, muscle, and fat mass accrual, as well as risk of non-communicable diseases in later life. Nutritional effects in adolescent development extend beyond musculoskeletal growth, to cardiorespiratory fitness, neurodevelopment, and immunity. High rates of early adolescent pregnancy in many countries continue to jeopardise the growth and nutrition of female adolescents, with consequences that extend to the next generation. Adolescence is a nutrition-sensitive phase for growth, in which the benefits of good nutrition extend to many other physiological systems.

Association between height growth patterns in puberty and stature in late adolescence: A longitudinal analysis in chinese children and adolescents from 2006 to 2016

INTRODUCTION

The relationship between the characteristics of puberty growth and the stature (height and overweight and obesity) in late adolescence was not clear. We aimed to explore the effects of puberty growth patterns on the stature in late adolescence.

METHODS

A total of 13,143 children from a longitudinal cohort from 2006 to 2016 in Zhongshan city of China were included. The Preece-Baines growth curve was fitted for each individual child, and the age at peak height velocity (APHV), peak height velocity (PHV), and age at take-off (TOA) were obtained from the Preece-Baines model. To compare the difference in height in late adolescence (at 18 years old) at different pubertal height growth patterns (height spurt timing, intensity, and duration), the height at baseline was matched by using the propensity score matching. The log-binomial model was applied to assess the association between the three pubertal height growth patterns (timing, intensity, and duration) and overweight and obesity status in late adolescence, controlling the urbanity and body mass index (BMI) at baseline.

RESULTS

After matching the baseline height, boys and girls in three pubertal patterns with early timing (P < 0.01), small intensity (P < 0.01), and short duration (P < 0.01) of height spurt had the lowest final height in the late adolescence. A 16% increase and 45% increase of risk for overweight and obesity were significantly associated with the early APHV in boys and girls, respectively, relative risk (RR) in boys, 1.16(95% confidence interval, CI: 1.03-1.30), P = 0.011; RR in girls, 1.45(1.21-1.75), P < 0.001. A 21% increase and 59% increase of risk for overweight and obesity were significantly associated with small PHV in boys and girls, respectively, RR in boys, 1.21(1.07-1.36), P < 0.001; RR in girls, 1.59(1.30-1.95), P < 0.001; and an 80% increase of risk for overweight and obesity with small spurt duration in girls (RR = 1.80; 95% CI: 1.49, 2.18; P < 0.001).

CONCLUSION

Pubertal growth patterns, including earlier puberty onset timing, smaller puberty intensity, and shorter puberty spurt duration, had a positive association with lower height risks and higher overweight and obesity risks in late adolescence.

Relationship between body composition and pulmonary function in healthy adolescents

BACKGROUND

It has been long established that body composition affects pulmonary function but little attention has been given to assessing lung function in healthy adolescents and determining the influence of body composition on these variables.

METHODS

We measured 399 boys (mean age 16.7 ± 1.2 years) and 46 girls (mean age 17.1 ± 1.2 years). We used multi-frequency segmental bioimpedance analyzer Tanita MC 980-MA Plus for body composition parameters and Micro Direct MicroGP Spirometer MS07 for spirometry parameters.

RESULTS

Mean body height was 179.5 cm and mean body mass index was 22.5 kg/m² in boys. In girls, mean body height was 166.9 cm and body mass index was 22.5 kg/m² . After adjusting for age, body height, bodyweight, and smoking status, we found a significant (P = 0.01) association (β = 0.35-0.43) between forced vital capacity and fat-free mass (FFM) or trunk fat-free mass only in boys. Similarly, body fat mass (BFM) showed significant (P = 0.01) negative association (β = -0.29 to -0.20) with spirometry parameters only in boys. In girls, the results showed a similar trend but it was not significant.

CONCLUSIONS

In conclusion, FFM or trunk FFM is more closely related to lung capacity than BFM or trunk BFM after adjustment for confounding variables in healthy adolescent boys. Body height explained up to 23% variability of forced vital capacity and fat-free mass explained up to 27% in a linear regression model.

Gender Specificity and Local Socioeconomic Influence on Association of GHR fl/d3 Polymorphism With Growth and Metabolism in Children and Adolescents

OBJECTIVE

Growth hormone receptor (GHR) mediates most GH biological actions. This study is aimed to evaluate whether GHR fl/d3 polymorphism contributes to the inter-individual variability of growth and metabolism in healthy children and adolescents.

METHODS

A total of 4,730 students aged 6-16 years from Yixing and Suqian City in China were included in this cross-sectional study. Height and body mass index (BMI) were transformed into the form of z-score corresponding to age and gender. Logistic regression was used to evaluate the associations of GHR fl/d3 polymorphism with height, BMI, metabolic traits, and hypertension by estimating the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

GHR d3 allele was inversely associated with overweight, total cholesterol (TC) and triglyceride (TG) levels (OR [95% CI] for overweight: 0.754 [0.593-0.959], P = 0.021; OR [95% CI] for TC: 0.744 [0.614-0.902], P = 0.003; OR [95% CI] for TG: 0.812 [0.654-0.998], P = 0.047). GHR d3 allele was associated with decreased odds of pre-hypertension in boys (OR [95% CI]: 0.791 [0.645-0.971], P = 0.025), but associated with increased odds of pre-hypertension and hypertension in girls (ORs [95% CIs]: 1.379 [1.106-1.719], P = 0.004; OR [95% CI]: 1.240 [1.013-1.519], P = 0.037). Interaction of GHR fl/d3 polymorphism with gender contributed to increased odds of pre-hypertension and hypertension (interactive ORs [95% CIs]: 1.735 [1.214-2.481], P = 0.003; OR [95% CI]: 1.509 [1.092-2.086], P = 0.013). Stratification analysis showed that the correlation tendencies of GHR fl/d3 polymorphism and BMI with age were different between two cities with discrepant economic development levels.

CONCLUSION

GHR fl/d3 polymorphism is associated with growth, metabolism, and hypertension in children and adolescents with the gender specificity, and the genetic effect of GHR fl/d3 may be modified by the local socioeconomic levels.

The Different Effects of Skeletal Muscle and Fat Mass on Height Increment in Children and Adolescents Aged 6-11 Years: A Cohort Study From China

OBJECTIVE

This study aimed to investigate the contribution of body composition including skeletal muscle mass (SMM) and body fat mass (BFM) to longitudinal growth among children and adolescents aged 6-11 years old.

METHODS

This cohort study was conducted from the annual health examination between 2019 and 2020. Annual height gain and weight gain and changes in SMM and BFM were calculated and compared between sexes, different nutritional status, and growth curve shifting mode. Spearman analyses and multiple linear regression analysis were performed to identify the impact of SMM, BFM, or body mass index (BMI) on height gain.

RESULTS

Of the 584 subjects, the annual height gains of boys (4.76 cm in the 6-9-year group and 4.63 cm in the 10-11-year group) were significantly lower than those of girls (5.48 and 5.74 cm, respectively). Spearman analysis showed that SMM gain and height gain were positively and significantly correlated in each examination of all children (r = 0.535 for boys and 0.734 for girls, p < 0.001). Conversely, BFM and height gains were negatively (r = -0.5240 for boys and -0.232 for girls, p < 0.001) correlated. Multiple linear regression analysis identified SMM gain as an independent predictor (95% CI: 1.20,1.44) of height gain after adjusting for age, gender, BMI, BFM gain, and percentage of body fat (PBF).

CONCLUSION

SMM gains, rather than BFM gains, were associated with height gains in children and adolescents aged 6-11 years. Monitoring SMM changes in routine healthcare might motivate children and adolescents to achieve dietary and exercise recommendations, thereby growing taller without gaining excessive weight.

Characteristics of inhomogeneous lower extremity growth and development in early childhood: a cross-sectional study

BACKGROUND

Early childhood is a transferring stage between the two accelerated growth periods (infant and adolescent). Body dimensions are related to physical growth and development. The purpose of this study was to investigate physical growth in terms of anthropometry, muscle growth of the lower extremity, and functional development over early childhood.

METHODS

A cross-sectional study was carried out on 29 preschool children (PS: 3-5 years), 21 school children (SC: 6-8 years), and 22 adults (AD: 20-35 years). Lower extremity characteristics (segmental dimensions, muscle and adipose tissue thicknesses of the thigh and lower leg), and voluntary joint torque (knee and ankle) were measured. Correlations between parameters and group comparisons were performed.

RESULTS

All the parameters except for body mass index (BMI) and subcutaneous adipose tissue thickness were correlated with age for PS and SC combined (r = 0.479-0.920, p < 0.01). Relative thigh and shank lengths to body height were greatest in AD and smallest in PS (p < 0.05) but the relative foot dimensions were significantly larger in PS and SC than in AD (p < 0.05). Relative subcutaneous adipose tissue thickness was largest in PS and lowest in AD. Muscle thickness and the muscle volume measure (estimated from muscle thickness and limb length) were significantly larger in older age groups (p < 0.05). All groups showed comparable muscle thickness when normalized to limb length. Joint torque normalized to estimated muscle volume was greatest for AD, followed by SC and PS (p < 0.05).

CONCLUSIONS

Relative lower extremity lengths increase with age, except for the foot dimensions. Muscle size increases with age in proportion to the limb length, while relative adiposity decreases. Torque-producing capacity is highly variable in children and rapidly develops toward adulthood. This cross-sectional study suggests that children are not a small scale version of adults, neither morphologically nor functionally.

Relationships of sex hormones with muscle mass and muscle strength in male adolescents at different stages of puberty

This study analysed the associations of sex steroids with fat-free mass (FFM) and handgrip strength in 641 Chinese boys. Serum total testosterone (TT) and oestradiol were measured by chemiluminescence immunoassay. Free testosterone (FT) and oestradiol were calculated. FFM and handgrip strength were measured by bioelectrical impedance analysis and a hand dynamometer, respectively. Generalised additive models and multiple linear regression were used to explore the relationships. A subgroup analysis was conducted in early-mid pubertal and late-post pubertal groups. Age, height, weight, physical activity, intake of dietary protein and/or stage of puberty were adjusted. TT and FT were positively related to FFM and handgrip strength, with a curvilinear relationship being detected for handgrip strength (p<0.050). This curvilinear relationship was only observed in the late-post pubertal group, suggesting a potential threshold effect (FT>11.99ng/dL, β = 1.275, p = 0.039). In the early-mid pubertal group, TT and/or FT were linearly or near-linearly related to FFM or handgrip strength (β = 0.003–0.271, p<0.050). The association between FT and FFM was stronger than that in the late-post pubertal group. This study found that serum T had different associations with muscle parameters in Chinese early-mid pubertal and late-post pubertal boys. In the late-post pubertal boys, serum T was curvilinearly related to muscle strength with a threshold effect and its link with muscle mass was weaker.

Associations between Spanish children's physical activity and physical fitness with lean body mass: The CALINA study

The present study investigated the associations between physical activity (PA) and physical fitness (PF) with lean body mass (LBM) and evaluated whether PA mediates the association between PF and LBM. 279 children (150 boys) aged 7.5 ± 0.3 years participated in the study. PA was assessed by accelerometry and PF with handgrip and the standing long jump test. Total lean soft tissue mass index (TLSTMI), muscle cross-sectional area index (MCSAI), and fat-free mass index (FFMI) were evaluated using dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and bioimpedance analysis, respectively.Total (β = 0.247) and vigorous PA (β = 0.143) were associated with TLSTMI in girls. In boys, total (β = 0.337), light (β = 0.290), vigorous (β = 0.200), and moderate-vigorous PA (β = 0.189) were associated with TLSTMI. Total PA was associated with FFMI (β = 0.299). Handgrip strength does not mediate the relationship between total PA and TLSTMI. Positive associations were found between handgrip strength and TLSTMI, MCSAI, and FFMI in both girls and boys.In children, there is a positive association between total and vigorous PA with TLSTMI. Handgrip strength does not mediate the relationship between total PA and TLSTMI. It was associated with TLSTMI, MCSAI, and FFMI.

A narrative review of skeletal muscle atrophy in critically ill children: pathogenesis and chronic sequelae

Muscle wasting is now recognized as a growing, debilitating problem in critically ill adults, resulting in long-term deficits in function and an impaired quality of life. Ultrasonography has demonstrated decreases in skeletal muscle size during pediatric critical illness, although variations exist. However, muscle protein turnover patterns during pediatric critical illness are unclear. Understanding muscle protein turnover during critical illness is important in guiding interventions to reduce muscle wasting. The aim of this review was to explore the possible protein synthesis and breakdown patterns in pediatric critical illness. Muscle protein turnover studies in critically ill children are lacking, with the exception of those with burn injuries. Children with burn injuries demonstrate an elevation in both muscle protein breakdown (MPB) and synthesis during critical illness. Extrapolations from animal models and whole-body protein turnover studies in children suggest that children may be more dependent on anabolic factors (e.g., nutrition and growth factors), and may experience greater muscle degradation in response to insults than adults. Yet, children, particularly the younger ones, are more responsive to anabolic agents, suggesting modifiable muscle wasting during critical illness. There is a lack of evidence for muscle wasting in critically ill children and its correlation with outcomes, possibly due to current available methods to study muscle protein turnover in children-most of which are invasive or tedious. In summary, children may experience muscle wasting during critical illness, which may be more reversible by the appropriate anabolic agents than adults. Age appears an important determinant of skeletal muscle turnover. Less invasive methods to study muscle protein turnover and associations with long-term outcome would strengthen the evidence for muscle wasting in critically ill children.

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.

Cellular heterogeneity and immune microenvironment revealed by single-cell transcriptome in venous malformation and cavernous venous malformation

Venous malformation (VM) and cavernous venous malformation (CVM) are two types of vascular malformations. Even if the two diseases are similar in appearance and imaging, the distinct cellular components and signaling pathways between them might help distinguish the two from a molecular perspective. Here, we performed single-cell profiling of 35,245 cells from two VM samples and three CVM samples, with a focus on endothelial cells (ECs), smooth muscle cells (SMCs) and immune microenvironment (IME). Clustering analysis based on differential gene expression unveiled 11 specific cell types, and determined CVM had more SMCs. Re-clustering of ECs and SMCs indicated CVM was dominated by arterial components, while VM is dominated by venous components. Gene set variation analysis suggested the activation of inflammation-related pathways in VM ECs, and upregulation of myogenesis pathway in CVM SMCs. In IME analysis, immune cells were identified to accounted for nearly 30% of the total cell number, including macrophages, monocytes, NK cells, T cells and B cells. Notably, more macrophages and monocytes were discovered in VM, indicating innate immune responses might be more closely related to VM pathogenesis. In addition, angiogenesis pathway was highlighted among the significant pathways of macrophages & monocytes between CVM and VM. In VM, VEGFA was highly expressed in macrophages & monocytes, while its receptors were all abundantly present in ECs. The close interaction of VEGFA on macrophages with its receptors on ECs was also predicted by CellPhoneDB analysis. Our results document cellular composition, significant pathways, and critical IME in CVM and VM development.

Physical Growth of Patients with Hereditary Tyrosinaemia Type I: A Single-Centre Retrospective Study

In a retrospective review, we aimed to assess long-term growth in 17 patients (n = 11 males) with hereditary tyrosinaemia type I (HTI). Median age at assessment was 15.6 years (5.7-26.6 years) and median age at diagnosis was 1 month (range: 0-16 months), with 35% (n = 6/17) symptomatic on presentation. From the age of 8 years, there was a noticeable change in median height, weight, and body-mass-index [BMI]-z-scores. Median height-for-age z-scores were consistently ≤ -1 (IQR -1.6, -0.5) during the first 8 years of life but increased with age. Weight-for-age z-scores ranged between -1 to 0 (IQR -1.2, 0.1) in the first 8 years; then increased to > 0.5 (IQR -0.3, 1.3) by age 16 years, and BMI-for-age z-scores ranged from 0 to 1 (IQR -0.7, 1.3) up to 8 years, and >1 (IQR -0.2, 1.9) until 16 years. The percentage of overweight and obesity was lowest in children aged < 5 years, and consistently > 40% in patients aged between 7 to 16 years. The prescribed total protein intake was associated with improved height growth (p < 0.01). Impaired growth in early life improved with age achieving normal population standards. Further studies are needed to investigate factors that influence growth outcome in HTI patients.

Association between skeletal muscle mass and mammographic breast density

Mammographic density (MD) of the breast and body mass index (BMI) are inversely associated with each other, but have inconsistent associations with respect to the risk of breast cancer. Skeletal muscle mass index (SMI) has been considered to reflect a relatively accurate fat and muscle percentage in the body. So, we evaluated the relation between SMI and MD. A cross-sectional study was performed in 143,456 women who underwent comprehensive examinations from 2012 to 2016. BMI was adjusted to analyze whether SMI is an independent factor predicting dense breast. After adjustment for confounding factors including BMI, the odds ratios for MD for the dense breasts was between the highest and lowest quartiles of SMI at 2.65 for premenopausal women and at 2.39 for postmenopausal women. SMI was a significant predictor for MD, which could be due to the similar growth mechanism of the skeletal muscle and breast parenchymal tissue. Further studies are needed to understand the causal link between muscularity, MD and breast cancer risk.

Magnolia officinalis Ameliorates Dehydroepiandrosterone-Induced Polycystic Ovary Syndrome in Rats

Background: Polycystic ovary syndrome (PCOS) is a prevalent reproductive and metabolic disorder. Insulin resistance (IR) is highly associated with PCOS and aggravates its symptoms. Thiazolidinediones (TZDs), as insulin sensitizing agents, are PPARγ agonists that improve many of the symptoms of PCOS. The Magnolia officinalis extract (MOE) is a natural peroxisome proliferator activated receptor gamma (PPARγ) agonist that improves insulin sensitivity in experimental models. Objectives: Using a dehydroepiandrosterone (DHEA)-induced rat model of PCOS and IR, this study aimed to explore both the potential beneficial effects and the molecular mechanisms of action of MOE. Methods: Post-pubertal female Sprague Dawley rats were subcutaneously injected daily with DHEA (6 mg/100 g body weight) dissolved in sesame oil for 28 days (n = 30). Age- and weight-matched control rats received only sesame oil (n = 12). Afterward, 16 of the DHEA-injected rats, along with five control rats, were sacrificed for blood and tissue collection. The 14 remaining DHEA-injected rats received either treatment of 30 days of oral MOE (500 mg/kg) dissolved in dimethyl sulfoxide (DMSO) (n = 7), or oral DMSO only (n = 7). Meanwhile, the remaining control rats (n = 7) continued to receive daily oral DMSO for 30 days. At the end of the treatments, the rats were sacrificed for blood and tissue collection. Results: After 28 days, the DHEA-treated rats exhibited an increase in body weight as compared to controls (P < 0.05). DHEA injection induced a PCOS phenotype as evident by a statistically significant (P < 0.05) elevated serum luteinizing hormone (LH), and an increased number of cystically dilated follicles with thicker granulosa compared to controls. PCOS rats showed a statistically significant rise in fasting insulin with an increased homeostatic model assessment index of insulin resistance (HOMA-IR) as compared to controls (P < 0.05). Compared to the control group, PCOS rats had a statistically significant lower ovarian protein expression of PPARγ, insulin receptor substrate 1 (IRS1), and protein kinase B (Akt) by Western Blot (P < 0.05). Conversely, the PCOS group showed an increased mammalian target of rapamycin (mTOR) pathway activity as evident by an increase in the fraction of phosphorylated mTOR to total mTOR compared to the control group (P < 0.05). When treated for 30 days with oral MOE (500 mg/kg), the PCOS rats showed a statistically significant decrease in body weight and serum LH levels as compared to the non-treated PCOS rats (P < 0.05). The number of cystically dilated follicles in the MOE-treated PCOS rats was significantly reduced compared to the non-treated PCOS rats. In the MOE-treated PCOS rats, the ovarian protein expression of PPARγ, IRS1, and Akt was significantly increased, while the p-mTOR/mTOR expression was decreased compared to the non-treated PCOS group (P < 0.05). Conclusions: According to our results, the MOE ameliorated the DHEA-induced PCOS phenotype histologically, hormonally, and metabolically. Fundamentally, this explores the elusive pathophysiologic association between IR and PCOS by targeting pathways common to both disorders.

The evolution of perennially enlarged breasts in women: a critical review and a novel hypothesis

The possession of permanent, adipose breasts in women is a uniquely human trait that develops during puberty, well in advance of the first pregnancy. The adaptive role and developmental pattern of this breast morphology, unusual among primates, remains an unresolved conundrum. The evolutionary origins of this trait have been the focus of many hypotheses, which variously suggest that breasts are a product of sexual selection or of natural selection due to their putative role in assisting in nursing or as a thermoregulatory organ. Alternative hypotheses assume that permanent breasts are a by-product of other evolutionary changes. We review and evaluate these hypotheses in the light of recent literature on breast morphology, physiology, phylogeny, ontogeny, sex differences, and genetics in order to highlight their strengths and flaws and to propose a coherent perspective and a new hypothesis on the evolutionary origins of perennially enlarged breasts in women. We propose that breasts appeared as early as Homo ergaster, originally as a by-product of other coincident evolutionary processes of adaptive significance. These included an increase in subcutaneous fat tissue (SFT) in response to the demands of thermoregulatory and energy storage, and of the ontogenetic development of the evolving brain. An increase in SFT triggered an increase in oestradiol levels (E2). An increase in meat in the diet of early Homo allowed for further hormonal changes, such as greater dehydroepiandrosterone (DHEA/S) synthesis, which were crucial for brain evolution. DHEA/S is also easily converted to E2 in E2-sensitive body parts, such as breasts and gluteofemoral regions, causing fat accumulation in these regions, enabling the evolution of perennially enlarged breasts. Furthermore, it is also plausible that after enlarged breasts appeared, they were co-opted for other functions, such as attracting mates and indicating biological condition. Finally, we argue that the multifold adaptive benefits of SFT increase and hormonal changes outweighed the possible costs of perennially enlarged breasts, enabling their further development.