Percent body fat at age 5 predicts earlier pubertal development among girls at age 9

Examining Health Behaviors as Mechanisms Linking Earlier Pubertal Timing with Accelerated Epigenetic Aging in Late Adolescence

Earlier pubertal timing is associated with accelerated epigenetic aging, but the underlying mechanisms are not well understood. This three-wave longitudinal study examined negative health behaviors, specifically substance use, short sleep duration, and poor diet quality in middle adolescence, as mediators of links between earlier phenotypic and perceived pubertal timing measured in early adolescence and epigenetic aging on three epigenetic clocks in late adolescence (GrimAge, DunedinPACE, and PhenoAge). Phenotypic pubertal timing measured physical pubertal maturation relative to chronological age, whereas perceived pubertal timing was based on adolescents' subjective interpretation of their pubertal timing relative to their peers. Participants included 1213 youth (51% female, 49% male; 62% Black, 34% White) who participated during early adolescence (mean age = 13.10 years), middle adolescence (mean age = 16.1 years) and late adolescence (mean age = 19.7 years). Results from a mediation model revealed a mediation effect of earlier phenotypic pubertal timing on accelerated GrimAge in late adolescence through higher substance use during middle adolescence. There was also a direct effect of earlier phenotypic pubertal timing on accelerated DunedinPACE in males. Sleep duration and diet quality did not emerge as mediators but shorter sleep duration predicted accelerated GrimAge in females. These findings suggest that higher substance use presents a mechanism through which earlier maturing youth experience faster epigenetic aging that puts them at risk for poorer health across the lifespan.

Prepubertal Children With Obesity Have High Free IGF-1 Levels and Accelerated Growth Despite Reduced Pappalysin Levels

BACKGROUND

Prepubertal children with obesity frequently have enhanced growth, accelerated skeletal maturation, and changes in the growth hormone-insulin-like growth factor (GH-IGF) axis. However, the involvement of pappalysins (PAPP-A, PAPP-A2) and stanniocalcins (STC1, STC2) as regulators of IGF bioavailability has not been studied in obesity.

OBJECTIVE

We aimed to determine the effects of childhood obesity and weight reduction on serum levels of PAPP-A, PAPP-A2, STC1, and STC2 and their relationship with IGF bioavailability, growth, and other components of the GH-IGF system.

METHODS

Prepubertal children with severe obesity (150, 50% males/females, age: 7.72 ± 2.05 years, BMI z-score: 4.95 ± 1.70, height z-score: 1.28 ± 1.04) were studied at diagnosis and after a minimum of 0.5 BMI z-score reduction. Two hundred and six healthy age- and sex-matched children were used as controls.

RESULTS

Children with obesity had decreased serum concentrations of PAPP-A, PAPP-A2 and STC2, but increased total and free IGF-I, intact IGFBP-3, acid-labile subunit (ALS), IGF-II, and insulin levels, with no difference in the free IGF-I/total IGF-I ratio. Neither the standardized body mass index (BMI) nor height correlated with any biochemical parameter analyzed. A decrease in IGF-II, insulin, and ALS with an increase in IGFBP-2 and -5, STC2, and PAPP-A were observed after weight loss.

CONCLUSION

Increased circulating total and free IGF-I, insulin, and IGF-II may all contribute to the increased rate of prepubertal growth and bone maturation observed in children with obesity, with STC2 possibly being involved.

Height estimation in children and adolescents using body composition big data: Machine-learning and explainable artificial intelligence approach

Objective

To develop an accurate and interpretable height estimation model for children and adolescents using body composition variables and explainable artificial intelligence approaches.

Methods

A light gradient boosting method was employed on a dataset of 278,301 measurements from 54,374 children and adolescents aged 6-18 years. The model incorporated anthropometric and body composition measures. Model interpretability was enhanced through feature importance analysis, Shapley additive explanations, partial dependence plots, and accumulated local effects.

Results

The models achieved high accuracy with mean absolute percentage errors of 1.64% and 1.63% for boys and girls, respectively. Soft lean mass (SLM), body fat mass percentage (BFMP), skeletal muscle mass, and skeletal muscle mass percentage were consistently identified as key factors influencing height estimation. Analysis revealed a positive correlation between SLM and estimated height, while BFMP exhibited an inverse relationship with height projections.

Conclusion

These findings provide valuable insights into the relationship between body composition and height, underlining the potential of body composition variables as accurate height predictors in children and adolescents. The model's interpretability and accuracy make it a promising tool for pediatric growth assessment and monitoring.

Association of Age at Menarche with General and Abdominal Obesity in Young Women

Background and Objectives: Age at menarche is related to various biological and socioeconomic factors in childhood. The aim of the study was to examine the association of age at menarche with general and abdominal obesity in young women. Materials and Methods: A transversal anthropometric survey was conducted with 102 females from 21 to 25 years of age. The surveyed traits included height, weight, waist circumference (WC) and hip circumference (HC). General obesity was assessed using the body mass index (BMI) and abdominal obesity by WC, waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR). A retrospective method was used for collecting age at menarche data. Results: The average age at menarche is 12.80 years. Early menarcheal age (<12 years) is detected in 25.5% of young females, while late onset of menarche (>14 years) is recorded for 20.6% of subjects. Early menarche age subjects exhibit significantly higher BMI, WC and WHtR in comparison with their late menarche age peers. There is a significant negative correlation between BMI, WC and WHtR values and menarcheal age. Late age at menarche is associated with higher probability of underweight status (BMI < 18.5 and/or WHtR < 0.4). Conclusions: Age at menarche has a negative correlation with general and abdominal obesity. Young women with early age at menarche show statistically higher values of BMI, WC and WHtR, while those with late menarcheal age show greater susceptibility to becoming underweight.

Pre-pubertal obesity compromises ovarian oxidative stress, DNA repair and chemical biotransformation

Obesity in adult females impairs fertility by altering oxidative stress, DNA repair and chemical biotransformation. Whether prepubertal obesity results in similar ovarian impacts is under-explored. The objective of this study was to induce obesity in prepubertal female mice and assess puberty onset, follicle number, and abundance of oxidative stress, DNA repair and chemical biotransformation proteins basally and in response to 7,12-dimethylbenz(a)anthracene (DMBA) exposure. DMBA is a polycyclic aromatic hydrocarbon that has been shown to be ovotoxic. Lactating dams (C57BL6J) were fed either a normal rodent containing 3.5% kCal from fat (lean), or a high fat diet comprised of 60% kCal from fat, and 9% kCal from sucrose. The offspring were weaned onto the diet of their dam and exposed at postnatal day 35 to either corn oil or DMBA (1 mg/kg) for 7 d via intraperitoneal injection. Mice on the HFD had reduced (P < 0.05) age at puberty onset as measured by vaginal opening but DMBA did not impact puberty onset. Heart, spleen, kidney, uterus and ovary weight were increased (P < 0.05) by obesity and liver weight was increased (P < 0.05) by DMBA exposure in obese mice. Follicle number was largely unaffected by obesity or DMBA exposure, with the exception of primary follicle number, which were higher (P < 0.05) in lean DMBA exposed and obese control relative to lean control mice. There were also greater numbers (P < 0.05) of corpora lutea in obese relative to lean mice. In lean mice, DMBA exposure reduced (P < 0.05) the level of CYP2E1, EPHX1, GSTP1, BRCA1, and CAT but this DMBA-induced reduction was absent in obese mice. Basally, obesity reduced (P < 0.05) the abundance of CYP2E1, EPHX1, GSTP1, BRCA1, SOD1 and CAT. There was greater (P < 0.05) fibrotic staining in obese DMBA-exposed ovaries and PPP2CA was decreased (P < 0.05) in growing follicles by both obesity and DMBA exposure. Thus, prepubertal obesity alters the capacity of the ovary to respond to DNA damage, ovotoxicant exposure and oxidative stress.

Growth in height and its association with overweight and obesity in Mexican children: an evaluation based on a nationally representative sample (ENSANUT 2018)

The present study aimed to estimate the height growth curve for Mexican boys and girls based on their body mass index (BMI) status (normal and overweight/obese) and to develop a height Lambda, Mu, and Sigma (LMS) growth reference for Mexican children aged 2 to 18 years.

Methods

Chronological age and height records (7,097 boys and 6,167 girls) were obtained from the Mexican National Survey of Health and Nutrition database. Height growth curves were fitted using the Preece-Baines 1 (PB1) model and the LMS method.

Results

Age at peak height velocity (APHV) was 12.4 and 12.7 years for overweight-obese and normal-weight boys, respectively, and was 9.6 and 10.4 years for overweight-obese and normal-weight girls, respectively. Growth velocity was higher at the age of take-off (TO) in overweight-obese children than in normal-weight children (5.2 cm/year vs. 5 cm/year in boys and 6.1 cm/year vs. 5.6 cm/year in girls); nevertheless, the growth velocity at APHV was higher for normal-weight children than for overweight-obese children (7.4 cm/year vs. 6.6 cm/year in boys and 6.8 cm/year vs. 6.6 cm/year in girls, respectively). Distance curves developed in the present study and by the World Health Organization (WHO) using LMS showed similar values for L and S parameters and a higher M value compared with the WHO reference values.

Conclusion

This study concluded that overweight-obese children had earlier APHV and lower PHV than normal-weight children. Furthermore, Mexican children and adolescents were shorter than the WHO growth reference by age and sex.

Childhood physical activity and pubertal timing: findings from the LEGACY girls study

BACKGROUND

There is limited research on whether physical activity (PA) in early childhood is associated with the timing of pubertal events in girls.

METHODS

We used data collected over 2011-16 from the LEGACY Girls Study (n = 984; primarily aged 6-13 years at study enrolment), a multicentre North American cohort enriched for girls with a breast cancer family history (BCFH), to evaluate if PA is associated with age at thelarche, pubarche and menarche. Maternal-reported questionnaire data measured puberty outcomes, PA in early childhood (ages 3-5 years) and total metabolic equivalents of organized PA in middle childhood (ages 7-9 years). We used interval-censored Weibull parametric survival regression models with age as the time scale and adjusted for sociodemographic factors, and we tested for effect modification by BCFH. We used inverse odds weighting to test for mediation by body mass index-for-age z-score (BMIZ) measured at study enrolment.

RESULTS

Being highly active vs inactive in early childhood was associated with later thelarche in girls with a BCFH [adjusted hazard ratio (aHR) = 0.39, 95% CI = 0.26-0.59), but not in girls without a BCFH. In all girls, irrespective of BCFH, being in the highest vs lowest quartile of organized PA in middle childhood was associated with later menarche (aHR = 0.70, 95% CI = 0.50-0.97). These associations remained after accounting for potential mediation by BMIZ.

CONCLUSION

This study provides new data that PA in early childhood may be associated with later thelarche in girls with a BCFH, also further supporting an overall association between PA in middle childhood and later menarche.

Metabolic hormones are integral regulators of female reproductive health and function

The female reproductive system is strongly influenced by nutrition and energy balance. It is well known that food restriction or energy depletion can induce suppression of reproductive processes, while overnutrition is associated with reproductive dysfunction. However, the intricate mechanisms through which nutritional inputs and metabolic health are integrated into the coordination of reproduction are still being defined. In this review, we describe evidence for essential contributions by hormones that are responsive to food intake or fuel stores. Key metabolic hormones-including insulin, the incretins (glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1), growth hormone, ghrelin, leptin, and adiponectin-signal throughout the hypothalamic-pituitary-gonadal axis to support or suppress reproduction. We synthesize current knowledge on how these multifaceted hormones interact with the brain, pituitary, and ovaries to regulate functioning of the female reproductive system, incorporating in vitro and in vivo data from animal models and humans. Metabolic hormones are involved in orchestrating reproductive processes in healthy states, but some also play a significant role in the pathophysiology or treatment strategies of female reproductive disorders. Further understanding of the complex interrelationships between metabolic health and female reproductive function has important implications for improving women's health overall.

Time trends towards earlier puberty in boys and girls with type 1 diabetes: Insights from the German Diabetes Prospective Follow-up (DPV) registry, 2000 to 2021

AIM

To examine the time trends and factors associated with the onset of puberty in children with type 1 diabetes (T1D) using data from the German Diabetes Prospective Follow-up (Diabetes-Patienten-Verlaufsdokumentation [DPV]) registry.

METHODS

A total of 13 127 children with T1D, aged 6 to 18 years, were included in the analysis. Regression analysis was performed to investigate the relationship between diabetes duration, body mass index (BMI) standard deviation score (SDS), glycated haemoglobin (HbA1c) level, migration background, and the onset of puberty, stratified by sex.

RESULTS

Our findings revealed a significant trend towards earlier puberty in both girls and boys with T1D over the observed period (2000 to 2021). Puberty onset in girls (thelarche Tanner stage B2) decreased from 11.48 (11.35-11.65) years in 2000 to 10.93 (10.79-11.08) years in 2021 and gonadarche (Tanner stage G2/testicular volume >3 mL) decreased from 12.62 (12.42-12.82) years in 2000 to 11.98 (11.79-12.16) years in 2021 in boys (both P < 0.001). Longer diabetes duration, higher BMI SDS, and lower HbA1c level were associated with earlier puberty in both sexes (P < 0.001).

CONCLUSIONS

Our study highlights earlier puberty in children with T1D, influenced by BMI SDS, HbA1c level, and migration background. This has important implications for diabetes management and supporting healthy development. Further research is needed to understand the underlying mechanisms and develop potential interventions for this vulnerable population.

Serum 25-hydroxyvitamin D levels and the risk of idiopathic central precocious puberty in girls

INTRODUCTION

Prior studies have found inconsistent results regarding the relationship between vitamin D status and Idiopathic Central Precocious Puberty (ICPP).

OBJECTIVE

To assess the role of serum 25-hydroxyvitamin D (25 [OH]D) levels in ICPP development.

METHOD

The authors retrospectively collected data from 221 girls with ICPP and 144 healthy girls between January 2017 and December 2019. The participants' serum 25(OH)D levels were measured using an automatic chemiluminescence method, and the association between serum 25(OH)D levels and the risk of ICPP was assessed using multivariate logistic regression analysis. Odds Ratios (OR) with 95% Confidence Intervals (95% CI) were calculated as effect estimates.

RESULTS

Serum 25(OH)D levels in the ICPP group were significantly lower than those in healthy controls (p < 0.001). Multivariate analysis indicated that girls with insufficient vitamin D levels (OR = 0.201; 95% CI 0.094-0.428; p < 0.001) and sufficient vitamin D levels (OR = 0.141; 95% CI 0.053-0.375; p < 0.001) both had a lower risk of ICPP than girls with vitamin D deficiency. Moreover, the authors found that the height (p = 0.014), weight (p = 0.014), breast stage (p = 0.010), mother's height (p < 0.001), and luteinizing hormone/follicle-stimulating hormone ratio (p = 0.010) in girls with ICPP could be associated with levels of vitamin D.

CONCLUSION

This study found that a low serum 25(OH)D level is an independent risk factor for ICPP, and several characteristics of girls with ICPP could be affected by their vitamin D status.

Idiopathic adolescent scoliosis and obesity: prevalence study

PURPOSE

Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity that affects 5% of the population. This pathology has multiple known etiological factors such as family predisposition, female gender, low body mass index, decrease in lean and fat masses. However, recent studies suggest that ciliary dysfunction could be the origin of certain types of obesity and AIS. This study aims to verify the existence of a link between these two pathologies.

METHODS

A retrospective, cross-sectional, descriptive and monocentric study, based on a cohort of adolescents with obesity treated in a paediatric rehabilitation centre for specific care between 1 January 2010 and 1 January 2019. The prevalence of AIS was calculated by radiographic measurements. The diagnosis of AIS was established if the Cobb angle was ≥ 10°, associated with intervertebral rotation.

RESULTS

196 adolescents with obesity were included in the study (mean age 13.2 years, mean BMI 36 kg/cm2, gender ratio 2.1 of female to male.) The prevalence of AIS in adolescents with obesity was 12.2%, twice the prevalence of AIS in the general population. The characteristics of AIS in adolescents with obesity are predominantly female, 58.3% left thoracolumbar or lumbar principal curvatures, mean Cobb angle 26° and progressive in 29% of cases.

CONCLUSIONS

Our study established a correlation between AIS and obesity with a higher prevalence than in the general population. The morphology of these adolescents makes screening for AIS more difficult.

Associations of Obesity With Growth and Puberty in Children: A Cross-Sectional Study in Fuzhou, China

Objectives: To investigate the associations of obesity with growth and puberty in children. Methods: From November 2017 to December 2019, height, weight, and Tanner stages of 26,879 children aged 3-18 years in Fuzhou, China were assessed. Results: The obese group was significantly taller than the non-obese group after age 4 years for both genders, yet there was no significant difference in height between obese and non-obese group after 15.5 years old for boys and 12.5 years old for girls. The inflection points of significant growth deceleration in obese and non-obese groups were 14.4 and 14.6 years old for boys, and 11.8 and 12.8 years old for girls, respectively. The proportions of testicular development in boys with obesity and non-obesity were 7.96% and 5.08% at 8.5-8.9 years old, respectively, while the proportions of breast development in girls were 17.19% and 3.22% at age 7.5-7.9 years old, respectively. Conclusion: Children with obesity were taller in early childhood, earlier onset of puberty and earlier cessation of growth than children with non-obesity of the same age. However, there was sex dimorphism on the effect of obesity on the incidence of precocious puberty.

Impacts of the COVID-19 pandemic on the diagnosis of idiopathic central precocious puberty in pediatric females in New York City

BACKGROUND

The COVID-19 pandemic had profound effect on physical and mental health. Stress was due physical inactivity, increased screen time, social isolation, fear of illness/death, as well as relative lack of resources including healthy food and finances. These stressors may be associated with an increase in idiopathic central precocious puberty (ICPP).

OBJECTIVES

To assess the incidence of ICPP in females during the COVID-19 pandemic and compare biochemical and radiological parameters of females diagnosed in the previous two years, looking at associations among BMI, screen time, isolation, and stress in relation to the development of early puberty.

METHODS

A retrospective chart review was performed of females diagnosed with ICPP. We divided subjects into a pandemic group and pre-pandemic group based on time of diagnosis. We compared anthropometric, serologic and radiologic data between the two groups. To assess psychosocial stress, we reviewed a COVID-19 impact survey which was administered to families at our endocrine clinic.

RESULTS

There were a total of 56 subjects in the study; 23 subjects in the pre-pandemic group and 33 in the pandemic group. The pandemic cohort had significantly higher estradiol and LH levels and larger ovarian volumes. Survey results showed parental report of stress was moderate in 38 % of subjects and severe in 25 % of parents. In children, reported stress was moderate in 46 % of subjects.

CONCLUSIONS

As puberty is influenced by exogenous factors including weight gain and psychosocial stress, we suspect that the environmental stress surrounding the pandemic influenced the increase in ICPP.

Genetic prediction of age at menarche, age at natural menopause and type 2 diabetes: A Mendelian randomization study

BACKGROUND AND AIMS

The relationship between reproductive factors and type 2 diabetes (T2D) is controversial; therefore, we explored the causal relationship of age at menarche (AAM), age at natural menopause (ANM), with the risk of T2D and glycemic traits using two-sample Mendelian randomization.

METHODS AND RESULTS

We used publicly available data at the summary level of genome-wide association studies, where AAM (N = 329,345), ANM (N = 69,360), T2D (N = 464,389). The inverse variance weighting (IVW) method was employed as the primary method. To demonstrate the robustness of the results, we also conducted various sensitivity analysis methods including the MR-Egger regression, the weighted median (WM) and the MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test. After excluding IVs associated with confounders, we found a causal association between later AAM and reduced risk of T2D (OR 0.81 [95% CI 0.75, 0.87]; P = 2.20 × 10^-8), lower levels of FI (β -0.04 [95% CI -0.06, -0.01]; P = 2.19 × 10^-3), FPG (β -0.03 [95% CI -0.05, -0.007]; P = 9.67 × 10^-5) and HOMA-IR (β -0.04 [95% CI -0.06, -0.01]; P = 4,95 × 10^-3). As for ANM, we only found a causal effect with HOMA-IR (β -0.01 [95% CI -0.02, -0.005]; P = 1.77 × 10^-3), but not with T2D.

CONCLUSIONS

Our MR study showed a causal relationship between later AAM and lower risk of developing T2D, lower FI, FPG and HOMA-IR levels. This may provide new insights into the prevention of T2D in women.

Is early or late biological maturation trigger obesity? A machine learning modeling research in Turkey boys and girls

Biological maturation status can affect individual differences, sex, height, body fat, and body weight in adolescents and thus may be associated with obesity. The primary aim of this study was to examine the relationship between biological maturation and obesity. Overall, 1,328 adolescents (792 boys and 536 girls) aged 12.00 ± 0.94-12.21 ± 0.99 years, respectively (measured for body mass, body stature, sitting stature). Body weights were deter-mined with Tanita body analysis system and adolescent obesity status was calculated according to the WHO classification. Biological maturation was determined according to the somatic maturation method. Our results showed that boys mature 3.077-fold later than girls. Obesity was an increasing effect on early maturation. It was determined that being obese, overweight and healthy-weight increased the risk of early maturation 9.80, 6.99 and 1.81-fold, respectively. The equation of the model predicting maturation is: Logit (P) = 1/(1 + exp. (- (-31.386 + sex-boy * (1.124) + [chronological age = 10] * (-7.031) + [chronological age = 11] * (-4.338) + [chronological age = 12] * (-1.677) + age * (-2.075) + weight * 0.093 + height * (-0.141) + obesity * (-2.282) + overweight * (-1.944) + healthy weight * (-0.592)))). Logistic regression model predicted maturity with 80.7% [95% CI: 77.2-84.1%] accuracy. In addition, the model had a high sensitivity value (81.7% [76.2-86.6%]), which indicates that the model can successfully distinguish adolescents with early maturation. In conclusion, sex and obesity are independent predictors of maturity, and the risk of early maturation is increased, especially in the case of obesity and in girls.

Sexual minority status is associated with earlier recalled age of menarche: Evidence from the 2005-2016 National Health and Nutrition Examination Survey

INTRODUCTION

Menarcheal timing is associated with growth, development, health, wellbeing, and reproduction across the lifespan. Although sexual orientation is a known correlate of health and developmental inequities, relatively little evolutionarily framed research has investigated sexual orientation-based variation in maturational timing. To improve our understanding of menarcheal timing among sexual minority (SM) people, we use a biocultural-evolutionary life history lens that takes into account the stresses of minoritization to examine the relationship between sexual orientation and self-reported age at menarche in a sample of American adults.

METHODS

Using the U.S. National Health and Nutrition Examination Survey (NHANES), a large, nationally representative dataset (n = 9757), we fit multiple logistic regression models and survival curves to evaluate associations between sexual orientation, indicators of somatic and material resources during adolescence (e.g., education, citizenship, upper arm length), and self-reported menarche.

RESULTS

SM respondents were more likely to report earlier (by 4-5 months) ages of menarche (p < .001). Post-hoc tests revealed that these differences were driven by bisexual (p < .001) and same-sex experienced (p < .001) relative to heterosexual and lesbian/gay respondents. Earlier menarcheal timing among SM respondents persisted after adjusting for socio-demographic factors and proxies of developmental conditions.

DISCUSSION

Our findings reveal that SM status is associated with earlier ages of menarche, an important social and reproductive milestone. We argue that uniting life history theory with the minority stress hypothesis better explains differences in menarcheal timing by sexual orientation than previous paradigms. Investigators should attend to sexual orientation-based variation in maturational timing using holistic, inclusive approaches.

Associations between body mass index and pubertal development based on the outcomes of girls with early breast development

Objective

To investigate the associations between physical and pubertal development based on the breast development outcomes in girls.

Methods

This was a retrospective study. A total of 452 girls aged 6~8 years were included. Based on their breast development outcomes, the patients were divided into an idiopathic central precocious puberty (ICPP) group and a premature thelarche (PT) group. Anthropometry included measurements of height, weight, and BMI. ICPP was diagnosed when five diagnostic criteria from the current guidelines were met.

Results

The girls with breast development at initial evaluation had a median age of 6.9 years. In total, 31.4% of patients were diagnosed with ICPP, and ICPP was rare in girls <7 years old (19%). Patients who presented with recurrence of breast development in the PT group accounted for 38.4%. At initial evaluation, the height, weight, BMI and bone age (BA) of the girls in the PT group corresponded to those of a normally developing girl at ages 7.8 years, 8.2 years, 8.6 years and 7.6 years, respectively. The girls in the ICPP group had a mean age of 7.3 years, and their mean height, weight, and BMI were 129.6 cm, 28.4 kg, and 17.0 kg/m2, which corresponded to the mean of a normally developing girl at ages 8.5 years, 9.1 years, and 10.5 years, respectively; these patients had BA of 9.2 years. Additionally, based on receiver operating characteristic (ROC) curve analysis, when the basal luteinizing hormone (LH) level was 0.32 IU/L and BMI reached 16.4 kg/m2, CPP was diagnosed in patients meeting all five diagnostic criteria for CPP, and the specificity and sensitivity were 71.9% and 88.2%, respectively.

Conclusions

Girls with breast development before 8 years old had a high proportion of recurrence of breast development. The physical development of these girls at the time of breast development preceded that of normally developing girls by 1-2 years. BMI is an independent risk factor for early pubertal development, and is a simple and clear predictor of ICPP. In addition to the five classic diagnostic criteria, CPP is diagnosed when physical development corresponds to the mean for a 10.5 years old girl.

Prenatal programming of developmental trajectories for obesity risk and early pubertal timing

The thrifty phenotype and fetal overnutrition hypotheses are two developmental hypotheses that originated from the developmental origins of health and disease (DOHaD) perspective. The DOHaD posits that exposures experienced prenatally and early in life may influence health outcomes through altering form and function of internal organs related to metabolic processes. Obesity risk and early pubertal timing might be influenced by similar mechanisms. The thrifty phenotype hypothesis is primarily characterized by experiencing a deprivation of nutrients during gestation paired with an energy rich postnatal environment. The fetal overnutrition hypothesis says that obesity experienced prenatally will be associated with increased lifetime risk of obesity in the offspring. Both hypotheses were tested by examining developmental pathways from genetic and prenatal risk through early growth trajectories (birth to 7 years) to pubertal timing at age 11 years. Participants included 361 children adopted at birth (57% male; 57% non-Hispanic White, 11% Black, 9% Hispanic; adoptive family income Mdn = $70,000-$100,000, birth family income Mdn = < $15,000). Associations between boys' childhood body mass index (BMI) and pubertal timing were confounded by genetics, prenatal risk, and early growth. The thrifty phenotype hypothesis was partially supported for boys' childhood BMI (at ages 4 to 7 years). Both hypotheses were partially supported for girls' childhood BMI but not pubertal timing. A novel Gene × Prenatal Risk interaction showed that genetic risk predicted girls' childhood BMI most strongly at adequate compared with at excessive levels of gestational weight gain. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The effects of obesity on the menstrual cycle

The prevalence of childhood and adolescent obesity has significantly increased in the United States and worldwide since the 1970s, a trend that has been accelerated by the COVID-19 pandemic. The complications of obesity range from negative effects on the cardiovascular, endocrine, hepatobiliary, and musculoskeletal systems to higher rates of mental health conditions such as depression and eating disorders among affected individuals. Among adolescent girls, childhood obesity has been associated with the earlier onset of puberty and menarche, which can result in negative psychosocial consequences, as well as adverse effects on physical health in adulthood. The hormones leptin, kisspeptin and insulin, and their actions on the hypothalamic-pituitary-ovarian axis, have been implicated in the relationship between childhood obesity and the earlier onset of puberty. Obesity in adolescence is also associated with greater menstrual cycle irregularity and the polycystic ovary syndrome (PCOS), which can result in infrequent or absent menstrual periods, and heavy menstrual bleeding. Hyperandrogenism, higher testosterone and fasting insulin levels, and lower levels of sex hormone-binding globulin, similar to the laboratory findings seen in patients with PCOS, are also seen in individuals with obesity, and help to explain the overlap in phenotype between patients with obesity and those with PCOS. Finally, obesity has been associated with higher rates of premenstrual disorders, including premenstrual syndrome and premenstrual dysphoric disorder, and dysmenorrhea, although the data on dysmenorrhea appears to be mixed. Discussing healthy lifestyle changes and identifying and managing menstrual abnormalities in adolescents with obesity are key to reducing the obstetric and gynecologic complications of obesity in adulthood, including infertility, pregnancy complications, and endometrial cancer.

A synthesis of early antecedents of eating behavior and weight status in girls: The legacy of girls' NEEDS project

Dr. Leann Birch, an innovator in the field of children's eating behavior, was the first scientist to synergize the fields of developmental psychology and nutrition science. One of Leann's groundbreaking projects was the Girls' NEEDS Project (GNP), an NIH-funded observational study of the longitudinal development of eating and weight-related behaviors of girls across middle childhood and adolescence. At the time of GNP, obesity prevalence during childhood had roughly doubled during the previous two decades, research interest in dieting had increased as societal expectations of the 'thin ideal' got even thinner, and little was known about how environmental factors such as parenting influenced the development of maladaptive eating and weight-related behaviors. GNP resulted in over 70 publications, covering a range of topics from girls' dietary intake and physical activity to parental influences on girls' eating behavior, thus laying the groundwork for many topics in the obesity, food parenting, and dieting literature today. Therefore, this narrative review aims to summarize and synthesize the literature that resulted from the GNP and provide implications for future work building from this foundation.

Delayed Puberty Phenotype Observed in Noonan Syndrome Is More Pronounced in Girls than Boys

INTRODUCTION

Pubertal delay is described as one of the clinical features in Noonan syndrome (NS) and it may be one of the factors causing short adult height in those patients. The present study aimed at characterizing pubertal development in NS and identifying pubertal delay predictors.

METHODS

We analyzed 133 individuals with a molecular diagnosis of NS and clinical puberty evaluation. We characterized delayed puberty as pubertal onset after 12 years in girls and 13.5 years in boys, according to parameters of the Brazilian population. To investigate its predictors, we correlated the age at onset of puberty with several characteristics and genotype in a multilevel regression model. For comprehending pubertal development in NS, we assessed age and anthropometric measures at each Tanner stage and adult age.

RESULTS

The mean age at puberty onset for girls was 11.9 ± 1.9 years and for boys, 12.5 ± 1.7 years, significantly later than the Brazilian population (p = 0.025; p < 0.001). Girls (49.1%) presented delayed puberty more frequently than boys (27.9%, p = 0.031). Body mass index standard deviation scores (SDS) and insulin growth factor 1 SDS at puberty onset significantly predicted later puberty entry. Height gain from the onset of puberty to adult height was lower in children with pubertal delay.

CONCLUSION

Pubertal delay is characteristically found in children with NS, more frequently in females. The low weight of patients with NS could modulate the age of puberty, just as the increase in overweight/obesity in the general population has shown an effect on reducing the age of onset of puberty.

Trend in age at menarche and its association with body weight, body mass index and non-communicable disease prevalence in Indonesia: evidence from the Indonesian Family Life Survey (IFLS)

Background

In western countries, age at menarche (AAM) is nowadays lower than a century ago, coinciding with increased Body Mass Index (BMI) and prevalence of non-communicable diseases (NCD). This study aimed to determine the time trend in AAM, and its association with BMI and NCD prevalence at later age, in Indonesia.

Methods

We used secondary data of 15,744 women aged 15–65 years from the Indonesian Family Life Survey (IFLS) conducted in the period 1993 to 2015. Multiple linear regression was applied to determine the association of AAM with BMI, and Poisson regression with robust variance for investigating the association of AAM with NCD prevalence ratios. Models were adjusted for age, and effect modification by wealth status, living area, and region was investigated.

Results

AAM has significantly declined from 14.4 (SD:2.1) years of age in the 1940s to 13.4 y (SD:1.5) in the 1990s. AAM was inversely associated with BMI (β: − 0.30 kg/m², 95%CI: − 0.37, − 0.22) and body weight (β: − 0.67 kg, 95%CI: − 0.75, − 0.54), but was not associated with height. After adjustment for age, AAM was not associated with NCD, i.e. hypertension, type 2 diabetes mellitus, liver diseases, asthma, chronic lung diseases, cardiovascular diseases, stroke, cancer, or arthritis. Including BMI in the models did not change the results.

Conclusions

From the 1940s to 1990s, AAM has declined with 1 year in Indonesia. Women with earlier AAM had higher BMI and body weight at later age, but AAM was not associated with NCD prevalence in later life in the Indonesian population. Further longitudinal research is needed to disentangle the direction of causality of the associations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12995-3.

Obesity-related genetic polymorphisms are associated with the risk of early puberty in Han Chinese girls

OBJECTIVE

To explore the association between obesity and precocious puberty from the perspective of genetic polymorphism.

DESIGN

Two hundred and ninety-eight pairs of girls in early puberty and age-matched controls (±3 months) were recruited. The genotypes of four obesity-related single-nucleotide polymorphism (SNP) loci (rs10968576, rs12935153, rs4674340 and rs7635103) were determined and the effect of variation on early puberty in Chinese Han girls was evaluated. The unstimulated luteinizing hormone (LH), follicle-stimulating hormone and estradiol levels were also measured to determine the relationship with SNP polymorphisms.

RESULTS

The effect allele A of rs12935153 was associated with early puberty (odds ratio [OR] = 1.256, 95% confidence interval [CI]: 1.010-1.585), but the significance disappeared after multiple comparisons. After adjusting for body mass index, rs12935153 variation increased the risk of early puberty in additive (OR = 1.589, 95% CI: 1.222-2.066), dominant (OR = 1.788, 95% CI: 1.210-2.642) and recessive (OR = 1.915, 95% CI: 1.207-3.038) models of inheritance. Individuals harbouring AA genotype in rs12935153 had a risk of higher LH levels than that of wild type (OR = 1.668, 95% CI: 1.093-2.546).

CONCLUSIONS

The association between obesity and precocity can be explained from a genetic perspective. Our study suggests that variations in rs12935153 increase the risk of early puberty in Chinese girls. Further studies are needed to verify our findings.

Secular trends of age at menarche and the effect of famine exposure on age at menarche in rural Chinese women

BACKGROUND

Over the past few decades, more studies have suggested that the age at menarche (AAM) has continued to decline. However, the AAM for women in resource-constrained areas is not clear. Moreover, the association between the China famine and AAM is still unclear in rural regions.

AIM

The study aimed to investigate the secular trends of AAM for women born between 1935 and 2000 and to further explore the effect of famine on AAM in rural China.

SUBJECTS AND METHODS

The study included 23444 women participants from the baseline study of Henan Rural Cohort study. Changing AAM over time was analysed using linear regressions. Multinomial logistic regression was conducted to analyse the association between famine exposure and AAM subgroups.

RESULTS

The age-standardized mean AAM was 14.74 years. The average AAM declined from 16.98 years for those born in 1935 to 13.87 years for those born in 2000, a decline of 0.077 years per 1 year and 0.729 years per decade. Compared to the reference group, women exposed to famine during fetal, early childhood, middle childhood, and late childhood were 1.376 (95% CI, 1.071 - 1.769), 1.848(95% CI, 1.512 - 2.259), 2.084(95% CI, 1.725 - 2.518), and 2.146 (95% CI, 1.788 - 2.576) times more likely to be ≥18 years of AAM than unexposed famine women, respectively.

CONCLUSION

AAM showed a decreasing trend in rural China. Furthermore, both fetal and childhood famine exposure, especially in late childhood, were positively associated with increased AAM compared to unexposed famine.

Overweight/Obesity in Childhood and the Risk of Early Puberty: A Systematic Review and Meta-Analysis

PURPOSE

To determine the relationship between childhood overweight/obesity and early puberty in both boys and girls. Specifically, this is the first time to conduct a meta-analysis of the relationship between childhood overweight/obesity and early puberty in boys.

METHODS

Relevant studies were identified from PubMed, Web of Science, and EMBASE searches. The exposure of interest was overweight/obesity in childhood. Childhood was defined internationally as the age range of 0-18 years. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were performed to explore possible sources of heterogeneity and to assess the robustness of the results.

RESULTS

A total of 10 studies involving 13,338 girls and 12,796 boys were included. Results showed that childhood overweight/obesity were associated with a significantly higher risk of early puberty in girls [odds ratio (OR): 2.22, 95% CI: 1.65-2.99]. Although without statistical significance, a higher risk of early puberty was also found in boys who were overweight/obese in childhood (OR: 1.29, 95% CI: 0.98-1.70). Heterogeneity in the risk estimates of early puberty was partially explained by study design, sample size, follow-up duration, definitions of early puberty and confounders controlled. Sensitivity analyses validated the robustness of the findings.

CONCLUSIONS

Our findings showed that for girls the associate between overweight/obesity and early puberty is definite or strong whereas for males, such an association is possible, prompting that future studies need to further explore the possible relationship between overweight/obesity and early puberty in boys.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021264649, PROSPERO CRD42021264649.

Childhood Overweight and Obesity and Pubertal Onset Among Mexican-American Boys and Girls in the CHAMACOS Longitudinal Study

Secular trends in earlier initiation of puberty have been observed in recent decades. One risk factor appears to be increases in adiposity, as measured by body mass index. This trend is particularly notable among Latino populations, who have higher rates of overweight/obesity compared with non-Latino White youth. Previous research has focused primarily on White girls, resulting in data gaps regarding male puberty and among potentially high-risk populations. Using data from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study, we examined body mass index at age 5 years (2005-2006) and multiple markers of pubertal onset, assessed repeatedly and longitudinally at 7 in-person visits, starting at age 9 and continuing through age 14 (2009-2015), among 336 Mexican Americans in Salinas, California. We observed no associations among boys, but found significantly earlier thelarche in overweight (HR = 1.7, 95% CI: 1.1, 2.7) and obese girls (HR = 1.5, 95% CI: 1.0, 2.4), menarche in overweight girls (HR = 1.6; CI: 1.0, 2.4), and pubarche in obese girls (HR = 1.9; CI: 1.2, 3.0), compared with normal-weight girls. This study examined an understudied population and included key covariates, such as birth weight and early adverse events, which are typically omitted in studies.

The role of age at menarche and age at menopause in Alzheimer's disease: evidence from a bidirectional mendelian randomization study

The association between endogenous estrogen exposure and Alzheimer's disease (AD) remains inconclusive in previous observational studies, and few Mendelian randomization (MR) studies have focused on their causality thus far. We performed a bidirectional MR study to clarify the causality and causal direction of age at menarche and age at menopause, which are indicators of endogenous estrogen exposure, on AD risk. We obtained all genetic datasets for the MR analyses using publicly available summary statistics based on individuals of European ancestry from the IEU GWAS database. The MR analyses indicated no significant causal relationship between the genetically determined age at menarche (outlier-adjusted inverse variance weighted odds ratio [IVWOR] = 0.926; 95% confidence interval [CI], 0.803-1.066) or age at menopause (outlier-adjusted IVWOR = 0.981; 95% CI, 0.941-1.022) and AD risk. Similarly, AD did not show any causal association with age at menarche or age at menopause. The sensitivity analyses yielded similar results. In contrast, an inverse association was detected between age at menarche and body mass index (BMI, outlier-adjusted IVW β = -0.043; 95% CI, -0.077 to -0.009). Our bidirectional MR study provides no evidence for a causal relationship between the genetically determined age at menarche or age at menopause and AD susceptibility, or vice versa. However, earlier menarche might be associated with higher adult BMI.

Do Most 7- to 8-Year-Old Girls with Early Puberty Require Extensive Investigation and Treatment?

STUDY OBJECTIVE

To investigate the etiology, progression, and treatment of precocious puberty in 7- to 8-year-old girls with breast development. Additionally, we evaluated the value of diagnostic tests in differentiating rapidly progressive precocious puberty (RP-PP) and slowly progressive precocious puberty (SP-PP) in these girls.

DESIGN

Ambispective cohort study.

SETTING

Single-center, pediatric endocrinology unit.

PARTICIPANTS

Girls with breast development between the ages of 7 and 8 years and assessed between July 2016 and July 2018.

INTERVENTIONS

Collected of clinical data and followed-up for 2 to 3 years. Girls were divided into RP-PP and SP-PP groups.

MAIN OUTCOME MEASURES

Described the etiology, rate of progression of puberty, and proportion intervened and compared the results of auxiliary examinations between the groups.

RESULTS

A total of 212 girls were enrolled, of which 211 (99.53%) were diagnosed with central precocious puberty (CPP) and 1 with peripheral precocious puberty (PPP). Hypophysis magnetic resonance imaging revealed that none had pathological brain lesions requiring surgical intervention. A total of 95 girls (44.81%) developed RP-PP, and 117 girls (55.19%) developed SP-PP. A total of 31 girls (14.62%) with RP-PP received treatment due to deteriorated predicting adult height. As compared with the SP-PP group, the RP-PP group showed more advanced bone age (BA), a higher level of basal luteinizing hormone (LH), and larger ovarian volume and uterine volumes. Receiver operating characteristic analyses revealed that BA was the best at identifying girls with RP-PP.

CONCLUSION

The majority of girls with breast development between the ages of 7-8 years do not need treatment. BA is a useful preliminary test for identifying girls with RP-PP who are more likely to require treatment.

Pubertal mammary gland development is a key determinant of adult mammographic density

Mammographic density refers to the radiological appearance of fibroglandular and adipose tissue on a mammogram of the breast. Women with relatively high mammographic density for their age and body mass index are at significantly higher risk for breast cancer. The association between mammographic density and breast cancer risk is well-established, however the molecular and cellular events that lead to the development of high mammographic density are yet to be elucidated. Puberty is a critical time for breast development, where endocrine and paracrine signalling drive development of the mammary gland epithelium, stroma, and adipose tissue. As the relative abundance of these cell types determines the radiological appearance of the adult breast, puberty should be considered as a key developmental stage in the establishment of mammographic density. Epidemiological studies have pointed to the significance of pubertal adipose tissue deposition, as well as timing of menarche and thelarche, on adult mammographic density and breast cancer risk. Activation of hypothalamic-pituitary axes during puberty combined with genetic and epigenetic molecular determinants, together with stromal fibroblasts, extracellular matrix, and immune signalling factors in the mammary gland, act in concert to drive breast development and the relative abundance of different cell types in the adult breast. Here, we discuss the key cellular and molecular mechanisms through which pubertal mammary gland development may affect adult mammographic density and cancer risk.

Revisiting the critical weight hypothesis for regulation of pubertal timing in boys

BACKGROUND

Recent findings indicate that there is a body weight-sensing homeostatic regulation of body weight in postpubertal rodents and humans. It is possible that body weight sensing also might be involved in the regulation of pubertal timing. Although an early small study suggested that there is a critical body weight for pubertal timing in girls, most studies have focused on BMI and reported an inverse association between BMI and pubertal timing.

OBJECTIVES

In the present longitudinal well-powered cohort study, we revisited the critical weight hypothesis and tested if prepubertal body weight is a more robust inverse predictor of pubertal timing than prepubertal BMI in boys.

METHOD

We included men born during 1945-1961 (old cohort; n = 31,971) and men born during 1981-1996 (recent cohort; n = 1465) in the large BMI Epidemiology Study (BEST) Gothenburg (combined BEST cohort n = 33,436). Men with information on prepubertal body weight and BMI at 8 y of age and age at peak height velocity (PHV; an objective measure of pubertal timing) were included.

RESULTS

Body weight explained more of the variance in age at PHV than BMI in both the old cohort and the recent cohort (combined cohort, body weight 6.3%, BMI 3.6%). Both body weight (β: -0.24 SD/SD increase in weight; 95% CI: -0.25, -0.23) and BMI (β: -0.18 SD/SD increase in BMI, 95% CI: -0.19, -0.17) were inversely associated with age at PHV but the association for body weight was significantly more pronounced than the association for BMI (P < 0.001).

CONCLUSIONS

In conclusion, prepubertal body weight is a more robust inverse predictor of pubertal timing than prepubertal BMI in boys. We propose that body weight sensing constitutes a feedback mechanism to regulate pubertal timing.

Association between Dietary Habits and Parental Health with Obesity among Children with Precocious Puberty

Precocious puberty, resulting in various physical, mental, and social changes, may have negative consequences for children and their families. In this study, we investigated whether there were differences between parental obesity, children's and parent's awareness of body shape, and dietary habits according to obesity levels in children with precocious puberty. A total of 193 children (93.3% girls) diagnosed with precocious puberty were classified into three groups according to their obesity levels. Negative body shape awareness and dissatisfaction were significantly higher in the obese group than in the normal-weight group, and parents were more likely to perceive their children as fat than the children themselves. In addition, the obesity rate of parents in the obese group was higher, and the body mass indexes of children and parents were significantly correlated. The nutrition quotients (NQs) were revealed to be significantly lower in the obese group with significantly lower scores. The significant factors related to obesity were the awareness of a fatty body image and dissatisfaction, obesity of the parents, and the NQ. The results show that obese children with precocious puberty were more vulnerable to negative lifestyle, family environment, and self-esteem effects than their normal-weight peers. Therefore, various interventions, such as environmental management, psychological support, and nutrition education, are needed that focus on the obesity and health conditions of children with precocious puberty.

Pubertal timing and breast cancer risk in the Sister Study cohort

Background

Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort.

Methods

Women ages 35–74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure.

Results

During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03–1.46 for < 10 vs. 12–13 years) and menarche (HR = 1.10, 95% CI 1.01–1.20 for < 12 vs. 12–13 years) were positively associated with breast cancer risk. Pubertal tempo was not associated with breast cancer risk (HR = 0.99, 95% CI 0.97–1.02 per 1-year longer tempo). When considering early thelarche (< 10 years) and early menarche (< 12 years) jointly, women with both had a 30% greater risk of breast cancer compared with women with neither risk factor (95% CI 1.07–1.57). The association between age at thelarche and breast cancer risk did not significantly vary by birth cohort, race/ethnicity, childhood weight, or Bayesian family history score.

Conclusions

Earlier ages at thelarche and menarche may enhance susceptibility to breast carcinogenesis. Age at thelarche is an important risk factor to consider given secular trends towards earlier development.

Comparison of two different GnRH analogs' impact on final height in girls with early puberty: Triptorelin acetate vs. leuprolide acetate

CONTEXT

GnRHa treatment has been a standard of care in progressive early puberty (EP). Choice of the GnRHa formulation is dependent on the preference of the clinician.

OBJECTIVE

To compare the effects of triptorelin acetate (TA) and leuprolide acetate (LA) on anthropometry in girls with EP.

DESIGN

A descriptive observational study.

SUBJECTS AND METHODS

Girls diagnosed with central EP and treated with GnRHa at least for one year were included; treated with TA (n=46) and LA (n=35). First year anthropometric response and final height were evaluated.

RESULTS

The mean age at the initiation of GnRHa treatment of girls was 8.5±0.5 years. The ratio of obesity and of overweight was 7.4 and 25.9%, respectively. In both TA and LA groups, anthropometric data of the patients at initiation and at the first year of treatment were similar. Although growth velocity was similar in each group, in LA group height SDS at the first year of the treatment showed a significant decrease (p=0.045), but not in TA group (p=0.317). No significant ΔBMI was observed with treatment. The differences between FH - PAH at initiation (height gain) in TA and LA groups were 2.9±4.7 and 4.0±5.8 cm, respectively (p=.316). Height gain per treatment year was 1.7±3.0 cm.

CONCLUSIONS

There was a significant decrease in height SDS at the first year of leuprolid treatment, but not in triptorelin. Although these two analogs show similar effects on treatment, a not significant but slightly better benefit in leuprolide was observed.

Exploring the relationship between adolescent biological maturation, physical activity, and sedentary behaviour: a systematic review and narrative synthesis

CONTEXT

Across adolescence, there is a notable decline in physical activity in boys and girls. Maturational timing may be a risk factor for disengagement from physical activity and increased sedentary behaviours during adolescence.

OBJECTIVE

This systematic review aimed to summarise literature that examined the relationship between maturational timing, physical activity and sedentary behaviour in adolescents.

METHODS

Six electronic databases were searched for articles that assessed biological maturation and physical activity (including sports participation and active transportation) or sedentary behaviours in adolescents. Two reviewers conducted title, abstract, and full-text screening, reference and forward citation searches. Included articles were evaluated for quality using a standardised tool. A narrative synthesis was used to analyse the findings due to the heterogeneity of the studies.

RESULTS

Searches yielded 78 articles (64 unique studies) that met the inclusion criteria, representing 242,316 participants (153,179 unique). Studies ranged from 30.0% (low) to 91.7% (high) in quality. An inverse relationship between maturational timing and physical activity (in 50 and 60% of studies in boys and girls, respectively) and a positive relationship between maturational timing and sedentary behaviour (in 100% and 53% of studies in boys and girls, respectively) was most commonly reported. Evidence supporting an association between maturational timing, sports participation, and active transportation was inconsistent.

CONCLUSIONS

While this review demonstrates some evidence for early maturational timing as a risk factor for disengagement from physical activity and increase in sedentary behaviours, the reviewed literature also demonstrates that this relationship is complex. Future research that tracks maturity-related variations in physical activity and sedentary behaviours over adolescence is warranted.

Adult height after gonadotropin-releasing hormone agonist treatment in girls with early puberty: A meta-analysis

OBJECTIVE

This analysis of previously published reports was performed to examine the effects of gonadotropin-releasing hormone (GnRH) agonist treatment on adult height and the factors associated with adult height outcomes.

CONTEXT

GnRH agonists are first-line agents in the treatment of precocious puberty. However, studies regarding the treatment effect on subjects with early puberty have reported inconsistent results.

DESIGN

A total of 14 studies identified from a search of electronic databases (AMED, EMBASE, MEDLINE and RISS) were included. Controlled studies with girls who developed puberty before 10 years of age and measurements of the adult heights of the subjects were selected. Studies using only long-acting GnRH agonists to suppress puberty were included. Adult height, duration of the treatment, age at the start of treatment and bone age advancement were analysed.

RESULTS

The mean age of the subjects ranged from 6.3 to 9.0 years. The meta-analysis showed a pooled mean difference in adult height of 3.2 cm and a 95% confidence interval of 1.3-5.1 cm. The height difference between the treated subjects and controls was significantly associated with the duration of treatment (P = .005) rather than the age at the start of treatment (P = .084) or the difference between bone age and chronological age (P = .427).

CONCLUSIONS

Administration of GnRH agonists in girls who develop early puberty and demonstrate advanced bone age may be effective for increasing adult height, especially if a sufficiently long treatment duration can be achieved.

NAFLD in women: Unique pathways, biomarkers and therapeutic opportunities

Purpose of review

In this review article we evaluate sex differences in the natural history of NAFLD and highlight distinct risk profiles of women with NAFLD, as well as unique treatment considerations and research gaps.

Summary of findings

Reproductive factors, such as menopausal status should be considered when evaluating NAFLD risk in women, as well as additional reproductive risk factors such as age at menarche, presence of polycystic ovary syndrome, and gestational diabetes. Women do appear to have lower risk for hepatocellular carcinoma from NASH, as well as lower mortality from NASH cirrhosis than men, although among women, NASH is now the leading indication for liver transplant. Data on sex differences in biomarker development and clinical trials are lacking, and researchers should be encouraged to evaluate biomarker performance by sex, and specifically report clinical trial endpoints in women.

Early menarche as a risk factor for suicidal ideation in girls: The Korea youth risk behavior web-based survey

Puberty, at which point girls experience menarche, is a biologically and psychologically unstable period. This study investigated the association between early menarche and suicidal ideation in girls. This study analyzed data from approximately 35,000 girls from the Korea Youth Risk Behavior Web-Based Survey every year from 2011 to 2015. The odds ratios of suicidal ideation were compared between the early and average menarche groups. Generally, the odds ratios of suicidal ideation in girls with early menarche were significantly higher than those with average menarche.

Long-term effects of GnRH agonist treatment on body mass index in girls with idiopathic central precocious puberty

Introduction Studies evaluating effects of gonadotropin-releasing hormone agonist (GnRHa) on weight and body-mass-index (BMI) in girls with idiopathic central precocious puberty (iCPP) include short-term effects. The aim of this study is to investigate changes in BMI during and 2 years after completion of GnRHa to determine the factors that may impact BMI in girls with iCPP. Methods Medical files of 138 girls who completed GnRHa were evaluated. All patients had weight and height measurements at the beginning and end of treatment, and 111 patients had anthropometric measurements 2 years after the completion of treatment. Results In the beginning, 82 (59.4%) had normal weight (NW), 42 (30.4%) were overweight (OW), and 14 (10.2%) were obese (OB). Analysis of BMI-standard deviation score (SDS) in the whole group showed an overall increase during GnRHa treatment (0.92 ± 0.74 vs. 1.20 ± 0.51, p < 0.001). Changes in BMI-SDS (ΔBMI-SDS) during GnRHa differed between NW and OW/OB (0.45 ± 0.31 vs. 0.03 ± 0.20, p < 0.001). BMI-SDSs of both groups returned to baseline scores (or initial levels) 2 years after the completion of treatment. Two factors affecting ΔBMI-SDS in multiple linear regression analyses were baseline BMI and Δheight-SDS, both correlated negatively with ΔBMI-SDS. Conclusions The present study is one of the studies evaluating BMI change over a long period of time in girls with CPP. Although BMI-SDS increased during GnRHa in NW girls, it was reversible in follow-up after treatment. However, BMI-SDS did not change during and in follow-up in OW/OB girls. Conserving BMI-SDS in OW/OB girls may be related to the fact that weight management programs were recommended for these patients. Dietary recommendations should be provided for children with NW who undergo GnRHa, as is the case for OW patients.

Prevalência de sobrepeso e obesidade e fatores associados em mulheres de São Leopoldo, Rio Grande do Sul: um estudo de base populacional

Resumo Introdução O sobrepeso e a obesidade são multicausais, porém seus determinantes ainda não foram completamente estudados. Objetivo Estimar a prevalência de sobrepeso e de obesidade e os fatores associados. Método Estudo transversal de base populacional com 981 mulheres (20 a 60 anos) de São Leopoldo/RS. O peso e a altura foram aferidos para o cálculo do Índice de Massa Corporal (IMC). Mulheres com IMC entre 25,0 e 29,9 kg/m2 e IMC ≥ 30,0 kg/m2 foram classificadas com sobrepeso e obesidade, respectivamente. As razões de prevalência e os intervalos de confiança de 95% foram estimados por meio de regressão de Poisson. Resultados A prevalência de sobrepeso foi de 33% (IC95%: 30,1-36,0) e de obesidade foi de 31,2% (IC95%: 28,3-34,1). Após ajuste, maiores probabilidades de sobrepeso ocorreram em mulheres mais velhas, pertencentes às classes econômicas mais baixas, casadas ou em união, com histórico de obesidade materna e com uma ou mais gestações. As maiores probabilidades de obesidade ocorreram em mulheres mais velhas, de baixa renda, com histórico de obesidade materna e paterna e com três ou quatro gestações. Menarca acima de 12 anos e prática de atividade física de lazer foram fatores de proteção para a obesidade. Conclusão Esses resultados evidenciam a necessidade de ações de prevenção de longo prazo, algumas delas envolvendo ações transgeracionais.

Association of biological maturation with the development of motor competence in Austrian middle school students-a 3-year observational study

BACKGROUND

Motor competence is an important component in the facilitation of an active lifestyle and is influenced by environmental and biological constraints. Biological maturation has been shown to affect participation in various forms of physical activity (PA) and sports but information on the association with motor competence and motor development remains limited.

METHODS

A total of 212 (59% male) Austrian middle school students (10.8±0.5 years) were followed over 3 years. Participants completed annual anthropometric measurements along with the German motor test (Deutscher Motorik Test, DMT6-18) during a physical education lesson. Biological maturation was determined based on the estimated age at peak height velocity (APHV), as this has been shown to coincide with the onset of puberty.

RESULTS

Earlier maturation was associated with higher body weight and lower motor competence in boys and girls. Cross-sectional associations between motor competence and biological maturation, however, were limited after adjusting for body weight. Longitudinal results showed a more pronounced weight gain and impaired development of motor competence late maturing boys. In girls, weight gain was more pronounced with early maturation but this did not affect the development of motor competence. It was further shown that endurance capacity already declined in this cohort while agility increased.

CONCLUSIONS

The results of this study confirm the previously reported association between biological maturation and body weight, which also affects motor competence. Nevertheless, late maturing boys appear to be at a greater risk for excess weight gain, which negatively affects the development of motor competence during early adolescence. In girls, the association between weight change and development of motor competence was less clear. Of additional concern is the decline in cardiorespiratory fitness already during early adolescence as low cardiorespiratory fitness is associated with an increased risk for various chronic diseases later in life.

Adiposity and attained height in adolescents: a longitudinal analysis from the LabMed Physical Activity Study

Background To investigate the associations between adiposity and attained height over a 2-year period in healthy adolescents. Methods One thousand and seventeen adolescents aged 12-18 years participated in this cohort study; 893 (87.8%) were reevaluated 1 year later (T2) and 734 (72.2%) subjects 2 years later (T3). Body fat and anthropometry were measured according to standardized procedures. Socioeconomic status, pubertal stage and lifestyles determinants were gathered and used as confounders. Prospective associations between adiposity and height were examined using generalized linear models. Results Greater adiposity at T1 was significantly associated with a lower attained height over time, when adjusting for confounders, which varied between 0.03 and 1 cm in T2 and 0.1 and 1 cm in T3. Conclusions Excess of adiposity in early adolescence may exert an effect on attained height in late adolescence. This study supports future lifestyles intervention studies aiming at preventing overweight and obesity and improving attained height.

Early breast development in overweight girls: does estrogen made by adipose tissue play a role?

Background

Girls who are overweight/obese (OB) develop breast tissue but do not undergo menarche (the first menstrual period) significantly earlier than girls of normal weight (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that estrogen synthesized locally, in mammary fat, may contribute to breast development. This hypothesis would predict that breast development would be more advanced than other estrogen-sensitive tissues as a function of obesity and body fat.

Methods

80 pre-menarchal girls (26 OB, 54 NW), aged 8.2–14.7 yrs, underwent dual-energy x-ray absorptiometry to calculate percent body fat (%BF), Tanner staging of the breast, breast ultrasound for morphological staging, trans-abdominal pelvic ultrasound, hand x-ray (bone age), a blood test for reproductive hormones, and urine collection to determine the vaginal maturation index (VMI), an index of estrogen exposure in urogenital epithelial cells.

Results

When controlling for breast morphological stage determined by ultrasound, %BF was not associated with serum estrogen or gonadotropin (LH and FSH) levels or on indices of systemic estrogen action (uterine volume, endometrial thickness, bone age advancement, and VMI). Tanner breast stage did not correlate with breast morphological stage and led to misclassification of chest fatty tissue as breast tissue in some OB.

Conclusions

These studies do not support the hypothesis that estrogen derived from total body fat or local (mammary) fat contributes to breast development in overweight/obese girls.

Obesity Affects Submaximal Oxygen Uptake-Heart Rate Relationship and Exercise Economy Differently in Pre- and Post-pubescent Boys and Girls

The purpose of this study was to develop regression equations for estimating the intensity of the exercise work rate (relative peak oxygen uptake-heart rate [%VO2-HR]) and the metabolic energy expenditure (MEE) for exercise prescription and rehabilitation medicine that are specific to children. This study took into account that the specific data in terms of obesity, sex, and pubertal status are currently unavailable. Our hypothesis was that obesity would affect the submaximal exercise the oxygen uptake (VO2), heart rate (HR), and metabolic energy expenditure (MEE), and exercise economy (ExEco). In this retrospective study, the regression analysis was performed on 126 children, matching groups for Tanner pubertal status (prepubertal: 1.8±0.7; postpubertal: 4.1±0.7), BMI-for-age percentile (lean: 50±26; obese: 96±4), and sex (girls: 48%; boys: 52%). Percent peakVO2 was regressed against HR, MEE against work rate (watt), and exercise economy (ExEco, mLO2·kg lean body mass-1·min-1) against work rate. Additionally, stepwise linear regression was used to identify predictors for exercise peak work rate. Prepubertal and postpubertal boys exercise at lower work rates than obese (%peakVO2-HR slope; P=0.01). The reverse was true in girls, lean prepubertal work at lower compared lean postpubertal (%peakVO2-HR slope; P=0.03). Boys expend more calories during exercise compared to girls (MEE-slope; P=0.01), with no effect of puberty or obesity. Obese prepubertal children have poor ExEco compared to lean prepubertal children (ExEco-work rate slopes; P<0.01) but not in postpubertal children. Strong correlations (r=0.92-0.94) for %peakVO2-HR and MEE regressions for boys and girls accounted for 85-92% variation. Height, lean leg, and leg fat mass accounted for 83% of the variance for predicting peak work rate. Obesity, sex, and puberty affect exercise characteristics in children and should be considered for an individualized approach to exercise prescription in children.

Physiology of puberty in boys and girls and pathological disorders affecting its onset

Puberty is a physiological event involving the attainment of reproductive capability and complete development of sexual and physical organs. Changing from childhood to adulthood is a complex process and is tightly controlled by interconnection pathways at the level of the hypothalamus which can be influenced by environmental, psychosocial, and endocrine factors. Although various mechanisms underlying the onset of normal puberty have been investigated in humans and animals, the exact molecular mechanisms thereof remain unclear. The aim of this review is to summarize the current state of knowledge and provide a synoptic overview about the physiology of puberty in adolescent boys and girls, and describe pathological disorders affecting its onset.

The Role of Growth Hormone on Ovarian Functioning and Ovarian Angiogenesis

Although not yet well-understood, today it is clear that Growth Hormone (GH) exerts a relevant role in the regulation of ovulation and fertility; in fact, fertility is lower in women with GH deficiency (GHD), and GH receptors (GHR) and GH mRNA have been found in the ovary since the onset of follicular development in humans. However, despite the strong evidence of GH in the regulation of fertility, many aspects of GH actions at this level are still not well-established, and it is likely that some controversial data depend on the species analyzed, the dose of the hormone and the duration of use of GH. Folliculogenesis, ovulation, and corpus luteum formation and maintenance are processes that are critically dependent on angiogenesis. In the ovary, new blood vessel formation facilitates oxygen, nutrients, and hormone substrate delivery, and also secures transfer of different hormones to targeted cells. Some growth factors and hormones overlap their actions in order to control the angiogenic process for fertility. However, we still know very little about the factors that play a critical role in the vascular changes that occur during folliculogenesis or luteal regression. To promote and maintain the production of VEGF-A in granulosa cells, the effects of local factors such as IGF-I and steroids are needed; that VEGF-A-inducing effect cannot be induced by luteinizing hormone (LH) or chorionic gonadotropin (CG) alone. As a result of the influences that GH exerts on the hypothalamic-pituitary-gonadal axis, facilitating the release of gonadotropins, and given the relationship between GH and local ovarian factors such as VEGF-A, FGF-2, IGF-1, or production of sex steroids, we assume that GH has to be a necessary factor in ovarian angiogenesis, as it happens in other vascular beds. In this review we will discuss the actions of GH in the ovary, most of them likely due to the local production of the hormone and its mediators.

Is there a causal relationship between obesity and puberty?

The onset of puberty in adolescents and whether it is related to obesity is an ongoing topic for debate. Epidemiological cross-sectional and longitudinal studies show a shift towards earlier onset of puberty in girls who are obese; however, the situation is less clear in boys. Boys who are overweight seem to mature earlier, and boys who are obese mature later, than boys at a healthy weight. The underlying mechanisms are not yet fully understood, and whether earlier onset of puberty in obese girls is based on the activation of the hypothalamic-pituitary-gonadal axis is unclear. The most promising link between obesity and puberty is the adipokine leptin and its interaction with the kisspeptin system, which is an important regulator of puberty. However, peripheral action of adipose tissue (eg, via other adipokines, aromatase activity) could also be involved in changes to the onset of puberty. In addition, nutritional factors, epigenetics, or endocrine disrupting chemicals are potential mediators linking the onset of puberty to obesity. This Review summarises our knowledge concerning the relationship between obesity and onset and tempo of puberty, and the consequences of early puberty on obesity.

Association of prepubertal obesity with pubertal development in Chinese girls and boys: A longitudinal study

OBJECTIVES

The purpose of this study was to examine the association of prepubertal body mass index (BMI) and weight status with pubertal development in boys and girls in Chongqing, China.

METHODS

In a longitudinal study, 1237 students (695 boys and 542 girls) were recruited from Chongqing, China, and examined at baseline, then followed every 6 months for three and a half years. Height, weight, testicular volume, and breast development were measured at every examination. Age of first spermatorrhea and menarche were obtained from self-report. Subjects were divided into normal weight, overweight, and obese groups according to baseline BMI. Multivariable Cox regression analysis was used to examine the association of BMI and weight status with pubertal development.

RESULTS

In girls, higher prepubertal BMI increased the chance of earlier menarche (hazards ratio (HR): 1.205, 95% confidence interval (95% CI): 1.151-2.261) and breast development (HR: 1.092, 95% CI: 1.045-1.142). Girls in the overweight (HR: 2.605, 95% CI: 1.716-3.956) and obese (HR: 2.565, 95% CI: 1.603-4.103) groups had an increased risk of early menarche compared with those in the normal weight group, while only overweight was associated with an increased risk for earlier breast development (HR: 1.469, 95% CI: 1.024-2.108). In boys, higher prepubertal BMI was significantly associated with the timing of first spermatorrhea (HR: 1.054, 95% CI: 1.004-1.106) and testicular development (HR: 1.098, 95% CI: 1.063-1.135). Overweight (HR: 1.672, 95% CI: 1.204-2.322) and obesity (HR: 1.598, 95% CI: 1.135-2.249) increased the hazard of earlier testicular development compared with the normal weight group, while no significant differences were detected among the three weight groups in terms of time to first spermatorrhea.

CONCLUSIONS

Higher prepubertal BMI was associated with earlier puberty in both Chinese boys and girls.

A randomized controlled trial to prevent obesity among Latino paediatric patients

BACKGROUND

Obesity disproportionately affects Latino youth. Community clinics are an important resource, yet there is little evidence for the efficacy of clinic-based approaches in this population.

OBJECTIVE

The purpose of this study was to test the efficacy of a clinic-based intervention to lower body mass index (BMI) and improve body composition among overweight Latino children.

METHODS

A randomized trial (2 group × 3 repeated measures) was conducted among 297 randomly sampled, overweight paediatric patients (5-10 years old) and their parents. The 12-month family-based culturally tailored behavioural intervention (Luces de Cambio) was based on the 'traffic light' concepts to address behaviour change and was delivered by clinic health educators and mid-level providers. The primary study outcome was child BMI (kg m^-2 ) assessed at baseline, 6-month (n = 191) and 12-month (n = 201) post-baseline. A subsample of the children was examined for overall and site-specific adiposity using dual-energy X-ray absorptiometry (n = 79).

RESULTS

There were no significant intervention effects on child BMI (p > 0.05); however, intervention children showed significantly (p < 0.05) lower total and trunk per cent fat compared with the usual care condition.

CONCLUSIONS

The Luces intervention did not reduce child BMI, yet small but significant reductions were observed for child per cent body fat. Further research is needed to identify and reduce barriers to recruitment and participation among Latino families.

Promoting positive body image and tackling overweight/obesity in children and adolescents: A combined health psychology and public health approach

This article draws attention to the dual global problems of disordered eating and overweight/obesity among children and adolescents. It is well recognised that the main risk factor for disordered eating is body dissatisfaction, yet public health messages to tackle overweight/obesity are likely to increase body dissatisfaction. This tension between key public health messages and a health psychology approach is examined, with the goal of seeking a common way forward. We focus on the UK as a case study, where there is currently no statutory education in schools on body image. Since more prescriptive guidance on the curriculum covering personal/social/health issues is soon to be introduced, it is timely to consider the content, and in particular its impact on body image as well as overweight/obesity. Having reviewed current interventions and policy, we argue for a more holistic approach to the obesity problem, using a whole school approach to create a body confident culture.