Timing of Pubertal Milestones in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Early menarche is associated with disordered eating-results from a National Youth Survey

BACKGROUND

Disordered eating (DE) is highly prevalent among adolescents, though its definition varies. The association between DE and early pubertal maturation (EPM) remains underexplored in Israel, and has not been sufficiently examined using the widely-used SCOFF questionnaire. This study examines these associations in adolescents.

METHODS

Participants (n = 2415 girls, 2095 boys; ages 12-18 years) in a nationally-representative, cross-sectional Youth Health and Nutrition Survey (2015-2016) completed self-administered questionnaires, including the SCOFF questionnaire, and underwent anthropometric measurements. EPM was determined by menarcheal age <11.5 years in girls, and facial hair appearance <12.5 years in boys. Respondents affirming ≥2 SCOFF items were classified as DE cases. Multivariable logistic regression analyses examined the associations between EPM and DE.

RESULTS

Among the participants, 12.7% of the girls and 20.4% of the boys met EPM criteria; 55.5% and 33.7%, respectively, were categorized as having DE. Following adjustment for age, socioeconomic status, ethnic background, and weight status, EPM was significantly associated with DE in girls (OR 1.47, 95%CI: 1.12-1.93) and with 3/5 SCOFF items. No such association was found in boys (OR 1.00, 95%CI: 0.77-1.28).

CONCLUSION

EPM in girls was associated with DE. Identifying high risk groups for DE in adolescents is crucial for early intervention and prevention.

IMPACT

This study included a large, nationally representative sample of Israeli adolescents and utilized the SCOFF questionnaire, a widely used screening measure for disordered eating (DE). Following comprehensive analyses, a significant association between early pubertal maturation (EPM), defined as early menarche, and DE was documented in Israeli adolescent girls. Identifying girls with EPM and screening for disordered eating will allow for early interventions, potentially improving physical and mental health, and preventing progression to eating disorders.

Prevalence of Being Obese, Overweight, and Underweight Among Jordanian Children and Adolescents Based on International Growth Standards

OBJECTIVES

The rise of obesity and other nutrition-related conditions among children and adolescents is a global challenge, particularly in the Middle East. This study aimed to determine the prevalence of being underweight, overweight, and obese among Jordanian children and adolescents using the body mass index (BMI) percentiles of the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) standards.

METHODS

This retrospective cross-sectional/longitudinal study analyzed 58,474 (42.6% males; 57.4% females) height, weight, and BMI-for-age records from 31508 healthy Jordanian children and adolescents aged 2-19 years. The data were retrieved from the Ministry of Health's nationwide electronic database (2017-2023) and assessed using the CDC and WHO growth standards. Logistic regression was performed to assess the variables associated with overweight/obese status.

RESULTS

The prevalence of being underweight, overweight, and obese varied by the reference used, as more cases of being obese and underweight were reported when applying the CDC standards. The regression models showed the males had significantly lower odds of being overweight and obese than the females. Increased age was associated with higher odds of being overweight and obese, with annual increases observed across all age groups.

CONCLUSIONS

Using the WHO and CDC standards, the prevalence of being underweight was higher in the males aged 6 years and older, while being overweight and obese was more prevalent in the females. The observed annual increase in the prevalence of being overweight and obese underscores the need for targeted strategies. Growth references tailored to regional profiles may improve national nutrition policies for Jordanian children and adolescents.

A comic-based body image intervention for adolescents in semi-rural Indian schools: A randomised controlled trial

Adolescents in India experience body dissatisfaction and its associated adverse impacts on physical and mental health and gender equality. However, evidence-based interventions are scarce. Mental health interventions worldwide have traditionally relied upon delivery by expert providers. However, this prevents scalability, particularly in rural settings, where resources are often lacking. Therefore, this study evaluated the efficacy of a low-resource teacher-delivered mixed-gender comic-based body image intervention among adolescents in semi-rural Indian schools. A randomised controlled trial was conducted among 2631 students (50 % girls; classes 6 to 8; Mage = 12.03 years, SD = 1.22) across 41 schools around the Jaipur district in Rajasthan. Each school was randomly allocated to receive six comic-based intervention sessions (n = 1347) or lessons-as-usual (n = 1284; control). The primary outcome of body esteem and related secondary and exploratory outcomes assessing mental health and gender stereotyping were assessed at baseline, 1 week-post-intervention, and 3-months follow-up (ClinicalTrials.gov, NCT04317755). Linear Mixed Model analyses revealed that compared to the control group, intervention students reported significantly higher body esteem and skin shade satisfaction, and significantly lower eating pathology, internalisation of appearance ideals, and gender stereotyping, with all effects maintained at follow-up. Compared to control group, boys in the intervention group also demonstrated significantly higher body image-related life engagement and body hair satisfaction at follow-up. Both students and teachers indicated high intervention acceptability via quantitative and qualitative findings. These findings present the first effective teacher-delivered school-based body image intervention in India, which can be implemented at scale using minimal resources, and thus indicates promise regarding broader dissemination across urban and rural settings.

Earlier pubertal timing, not tempo, links time-limited early adversity with psychopathology

Evolutionary-developmental theories propose that early adverse experiences adaptively shift the timing (i.e., onset) and tempo (i.e., rate) of pubertal maturation. Empirical evidence of links between early life adversity and pubertal maturation is mixed, potentially in part because isolating the unique impacts of early environments is challenging. The current accelerated longitudinal study used a quasi-experimental design to examine pubertal maturation among 132 previously-institutionalized (PI), internationally adopted children who experienced a time-limited form of severe early life adversity, compared to 169 non-adopted (NA) children. Based on prior literature, we also assessed whether pubertal timing and/or tempo are pathways by which early adversity relates to later symptoms of psychopathology. At each of three annual sessions, Tanner pubertal staging was determined by nurse exam, and symptoms of psychopathology were captured in a composite of child self-reported internalizing and parent-reported externalizing symptoms. Findings revealed that, only among children at Tanner pubertal stages 3 or below, PI children were more likely to have reached stage 3 compared to NA children, reflective of earlier pubertal timing. No group differences were found for pubertal tempo. In the subsample of children at Tanner stage 3 or lower, earlier pubertal timing was an indirect pathway by which early adversity related to both higher levels and greater longitudinal declines in internalizing and externalizing symptoms of psychopathology, accounting for a small proportion of the total effect of early adversity on psychopathology. Results from this quasi-experimental study add to existing research on associations between early adversity, early pubertal timing, and psychopathology, further suggesting that links may be specific to timing but not tempo. While findings broadly align with recent calls to consider early pubertal maturation as a transdiagnostic risk marker with utility for identifying children who could benefit from early mental health intervention, they also suggest that pubertal timing is unlikely to be a robust target for reducing psychopathology risk in these children.

Anthropometric status, body composition and timing of pubertal milestones in Sub-Saharan Africa: a systematic review

BACKGROUND

With the rise of the triple burden of malnutrition, the changing nutrition situation in Sub-Saharan Africa may be associated with changes in pubertal timing of adolescents. The purpose of this review was to summarize the association between nutritional status and pubertal milestones among children in SSA.

METHOD

A search of publications was conducted in PubMed and Scopus on 1st April 2023. Observational studies with children aged 0 to 22 years, that reported nutritional status and association with pubertal milestones in SSA were selected for review. Risk of bias was assessed using the NOS and results were presented using the PRISMA.

RESULTS

Twenty-three studies published from 1992 to 2021 reporting data from nine countries and a total of 21,853 children were included in this review. Mean menarche age relative to nutritional status varied from 17.2 years in stunted adolescents in Senegal to 13.3 (in the underweight), 13.9 (in normal weight girls), and 14.1 (in overweight girls) years in adolescents in Ethiopia. Adolescents who were not stunted in Kenya and those with higher height-for-age z-scores (HAZ) and body mass index (BMI) in South Africa had more advanced breast development. Pubic hair development was positively associated with HAZ and BMI z-scores (BMIZ) at 5 years in South Africa and overweight and obesity in adolescents in Nigeria. Attainment of voice break in adolescent boys in Nigeria was associated with lower likelihood of stunting and underweight. In a study in Zambia, earlier onset and more rapid progression of genital development assessed by testicular volume in boys was associated with increased height and arm muscle.

CONCLUSIONS

Higher BMI, height, weight, and triceps skinfolds are significantly associated with advanced pubertal development in SSA. In SSA, less than one-third of the countries have published any research studies on nutritional status and pubertal milestones. Future studies should focus on detailed assessment of pubertal development and associated nutritional factors in both male and female adolescents in SSA.

PROSPERO REGISTRATION

CRD42022350048.

Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis

OBJECTIVE

Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events.

DATA SOURCES

PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022.

STUDY ELIGIBILITY CRITERIA

Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English.

METHODS

Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity.

RESULTS

In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance.

CONCLUSION

The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.

Longitudinal association between density of retail food stores and body mass index in Mexican school children and adolescents

BACKGROUND

Obesity is rapidly increasing in Mexican children and adolescents, while food environments are rapidly changing. We evaluated the association between changes in retail food stores and change in body mass index (BMI) in Mexican children and adolescents.

METHODS

Data on 7507 participants aged 5-19 years old came from the Mexican Family Life Survey 2002-2012. Density of food stores at the municipal-level (number of food stores/area in km²) came from the Economic Censuses of 1999, 2004 and 2009. We categorized food stores as small food retail (small neighborhood stores, tiendas de abarrotes in Mexico), specialty foods, fruit/vegetables, convenience foods, and supermarkets. Associations between change in food stores and change in BMI were estimated using five longitudinal linear fixed-effects regression models (one per type of food store) adjusted for age, parental education, municipal-level socioeconomic deprivation and population density. Density of each food store type was operationalized as quartiles. Analyses were stratified by urbanization.

RESULTS

There was an inverse dose-response association between increases in fruit/vegetable store density and BMI (β = -0.455 kg/m², β = -0.733 kg/m², and β = -0.838 kg/m² in the second, third, and fourth quartile). In non-urban areas, children living in municipalities with the highest density of small food retail stores experienced a reduction in BMI (β = -0.840 kg/m²). In urban areas, there was an inverse association between specialty food stores with BMI (β = -0.789 kg/m² in third quartile, and β = -1.204 kg/m² in fourth quartile). We observed dynamic associations with age; results suggested stronger associations in adolescents.

CONCLUSIONS

The availability of fruit/vegetable stores may influence a reduction in children and adolescents BMI. These results indicate that policy approaches could be tailored by type of food store - with some consideration for level of urbanization and children's age.

Exploring a faith-based approach to puberty education in Tanzania

Background

Many adolescents in Tanzania do not receive timely and comprehensive puberty education. This study explored faith-based organizations a site for puberty education. Two puberty books, each developed through participatory research with Tanzanian adolescents and stakeholders, were promoted to 177 Christian denomination churches in Dar es Salaam, Tanzania to understand the factors that faith leaders considered in their decision to purchase puberty books, or share information about the intervention to their peers and congregants.

Methods

Data collection included routine monitoring via weekly reports and ethnographic observation. Data were analyzed using the Ecological Framework for Health Promotion to capture how individual, interpersonal, and institutional factors influenced leaders' decisions to purchase or promote puberty books.

Results

At the individual level, leaders cited their personal experiences in their support for the intervention, but leaders' time and confidence in their ability to effectively promote books to others were barriers to participation. Interpersonally, the diffusion of information between church leaders, particularly when information came from well-known or respected leaders, emerged as an important factor in leaders' willingness to promote books. At the institutional level, leaders' decisions were impacted by resources, institutional culture, and institutional hierarchy. Importantly, twelve churches in the sample purchased books. Limited financial resources and the need to receive approval from denominational leaders were discussed by leaders as barriers to purchasing books.

Conclusions

Despite research showing high religiosity in Tanzania, the role of religious institutions in providing puberty education has remained unexplored. Our results inform future research and practice by providing an articulation of the socioecological factors that played a role in faith leaders' decisions related to puberty education interventions in Tanzania.

Secular trends in age at pubertal onset assessed by breast development among Chinese girls: A systematic review

Background

The average age at thelarche has trended downwards worldwide since 1970s; however, the onset age of "precocious puberty", defined as the lower percentiles of thelarche age, has been rarely reported. This systematic review aims to evaluate secular trends in age at thelarche among Chinese girls.

Methods

This systematic review on the age at thelarche during puberty among Chinese girls was conducted via systematic search of both Chinese (Chinese National Knowledge Infrastructure, WanFang Database, and the Chinese Scientific Journals Database) and English (PubMed, Cochrane Library, and Embase) databases. Data were analyzed using the GraphPad Prism v9.0.

Results

A total of 16 studies involving 177,886 Chinese girls were synthesized. The QualSyst scores of these studies were high at an average of 21.25. The timing of Tanner breast stage 2 (B2) occurred earlier over time at the P3, P10, and median ages. Weighted analyses revealed that the overall onset age of B2 tended to be younger at P3, P10, and P25. The age of B2 varied across regions and areas. For example, P3, P10, and median age of B2 in years were younger in southern regions than that in northern regions of China (P3: 5.94 vs. 7.3; P10: 6.6 vs. 7.9; median age: 8.26 vs. 9.5), and median age of B2 in urban areas (8.26 years) was earlier than that in rural areas (10.29 years). In addition, median age of B2 from 12 single-center studies was earlier than that from 4 multicenter studies (8.26 vs. 9.18 years).

Conclusions

The current findings indicated that pubertal breast development age among Chinese girls presented an advanced trend over the past 20 years, which urges the necessity to revisit and redefine "precocious puberty" and provides useful recommendations for clinical practice.

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.

Assessment of the median ages at sexual maturation stages of Brazilian schoolchildren according to overweight status and type of school over a 5-year period: 2007-2012/2013

OBJECTIVES

A secular trend of earlier puberty has been observed in girls, and, although more uncertain in boys, is associated with an increasing trend in the prevalence of overweight and obesity. We aimed to compare the median ages of sexual maturation stages in schoolchildren from a city in southern Brazil over a 5-year period, according to weight status and type of school.

METHODS

Two cross-sectional studies were performed in 2007 and 2012/2013, including 2215 and 1614 schoolchildren, respectively. Body mass index z-scores were calculated and categorized as either nonoverweight or overweight (including obesity). The type of school was categorized as either public or private. Sexual maturation was self-assessed according to the Tanner stages. Mann-Whitney and Kruskal-Wallis tests were performed to compare the median ages of sexual maturation stages.

RESULTS

The median age decreased for almost all stages over the 5-year period in both sexes. In boys, the decrease ranged from 0.3 to 1.0 years (stages 2, 3, 4, and 5 for genitalia, and stages 2 and 4 for pubic hair), and from 0.3 to 0.7 years (stages 2, 3, and 4 for breast, and stages 3, 4, and 5 for pubic hair). In 2012, overweight students had lower median ages for most stages compared to those in 2007, especially in girls. Differences by type of school were balanced across years.

CONCLUSIONS

The median age of Tanner's stages after 5 years was reduced in both sexes. In overweight girls, the reduction was more pronounced. The results by type of school were inconsistent.

The link between obesity and puberty: what is new?

PURPOSE OF REVIEW

The objective of this review is to assess the most recent literature on pubertal trends in boys and girls as well as evaluate genetic, epigenetic, and environmental factors implicated in the timing of pubertal progression.

RECENT FINDINGS

Recent studies confirm the previously described link between increased adiposity and earlier onset of puberty in girls, and more recent studies shed light onto the previously unclear situation in boys as a preponderance of recent longitudinal studies suggests that increased adiposity is linked with earlier pubertal timing also in boys. Discoveries of novel pathways highlights the complexity of pubertal development and suggest mechanistic links between nutrition, obesity, leptin, insulin resistance, and puberty. Furthermore, genetic and epigenetic variants can be linked to early puberty. Other factors, such as prenatal and postnatal environment, gut microbiota, and endocrine-disrupting chemicals have also been linked to both obesity and earlier puberty.

SUMMARY

Understanding how the interactions of these factors contribute the relationship between obesity and early pubertal onset is crucial as early puberty has been linked with long-term consequences, such as short stature, earlier type 2 diabetes, cardiovascular disease, and poor psychological and behavioral outcomes.

Characterization of pubertal development of girls in rural Bangladesh

This study aimed to describe the timing and patterns of pubertal maturation of girls living in rural Bangladesh. Starting in September 2015, a total of 15,320 girls from a birth cohort, aged 9 to 15 years at initial encounter, were visited twice at about a one year interval, typically in their birth month. Participants were asked to self-report extent of pubertal maturation, including breast development, pubic hair growth and age at menarche, if applicable. Pubertal stage (abbreviated as B2 and B3-4 for breast development and PH2 and PH3-4 for pubic hair growth) was assigned. Data from both visits were pooled, yielding a total of 29,377 age-related observations per pubertal characteristic. Probit regression models were used to estimate distributions of age at which each stage of pubertal development was attained. Before age 8, <3% of the study population initiated pubertal maturation as indicated by onset of breast development (B2). The median (95% confidence interval) age of B2 and B3-4 was 11.02 (11.00–11.04) and 12.82 (12.80–12.83) years, respectively; and 12.93 (12.91–12.94) and 14.29 (14.27–14.31) years for the onset (PH2) and advanced stage (PH3-4) of pubic hair growth, respectively. Median age at menarche was 13.17 (13.15–13.19) years, with 2.15 years of timespan from B2 to menarche. Girls in rural Bangladesh progressed through puberty following a well-documented sequence of sexual maturation stages. The age at which each pubertal milestone took place was somewhat later, but the tempo from breast development to menarche was comparable to that observed elsewhere. Our findings present a current norm of pubertal maturation in a typical, rural adolescent population in South Asia, which could help inform future studies and interventions to preserve or improve early adolescent health and development.

The relationship between pubertal timing and under-nutrition in rural Pakistan

INTRODUCTION

Sexual development in females and males are routinely measured according to the Tanner Stages. Sparse data exist on the timing of pubertal milestones in Pakistan. To fill this gap, the age of attainment of pubertal milestones and their relationship with nutritional status was explored among children and adolescents living in the rural district of Matiari, Pakistan.

METHODS

Anthropometry, nutrition biomarkers and Tanner Stage were assessed among girls aged 9.0-14.9 years (n = 723) and boys aged 10.0-15.9 years (n = 662) who were free from known disease in the rural District of Matiari, Pakistan. Median age was calculated for all Tanner Stages and menarche. Multivariable linear regressions were undertaken to determine covariates associated with the timing (age) of pubertal milestones.

RESULTS

Among participants living in this rural community, the median age of puberty onset for girls was 11.9 years (95%CI:10.9; 12.5) and boys was 12.3 years (95%CI:11.5; 12.9). Age at first menarche was 12.9 years (95%CI:12.1; 13.3). Undernutrition was widespread among adolescents in this community. Thirty-seven percent of females and 27.0% of males were stunted while 20.5% of females and 31.3% of males were thin. Only 8% (n = 58) of females and 12% (n = 78) of males were free from any nutrient deficiency with most adolescents having two or three nutrient deficiencies.

CONCLUSIONS

Undernutrition (stunting or thinness) was associated with relatively older ages for early puberty stages but not puberty completion. This may decrease the duration of the pubertal growth spurt and curtail potential catch-up growth that may occur during puberty. Efforts to decrease nutrient deficiencies, stunting and thinness beyond childhood should be made in rural Pakistan.

Longitudinal 15-year follow-up of women with former early puberty: abnormal metabolic profiles not associated with earlier age at onset of puberty, but associated with obesity

BACKGROUND

In 2011, we described 104 girls who were diagnosed as early puberty (EP) during 2003-2005. In 2019-2020, the former EP women had been followed up 14 years after attaining their final height.

OBJECTIVE

To determine the reproductive function and metabolic profiles of former EP women.

STUDY DESIGN

Fifty-seven former EP women were evaluated for reproductive function and examined for health status. Blood samples were obtained for metabolic profiles of glucose, lipids and insulin, and testosterone levels.

RESULTS

In 2020, the average age of the study women was 22.9 ± 1.7 years. The average height was 156.7 ± 5.6 cm. The average weight had increased from 52.5 ± 7.8 kg in 2011 to 58.5 ± 11.1 kg in 2020 and average body mass index (BMI) from 21.4 ± 2.9 to 23.8 ± 4.0 kg/m². Obesity (BMI>25 kg/m²) was found in 8.8% (five participants) in 2011 and had increased to 22.8% (13 participants) in 2020. Most participants (79%) had regular menstrual cycle. Of the 17 married women, 4 (23.5%) had 1-2 children. Dividing the participants into obese and nonobese groups, the average fasting plasma glucose, lipid profiles, and testosterone levels were similar in both groups. However, the average systolic blood pressure and the serum insulin levels and HOMA-IR assessments were significantly higher in the obese group than in the nonobese group.

CONCLUSION

The former EP women had normal menstruation and reproductive function. The former EP women with average BMI at the follow-up had normal metabolic profiles while those who later became obese had significantly higher systolic blood pressure, serum insulin, and HOMA-IR assessments.

Growth and socio-economic status, influence on the age at menarche in school going girls

INTRODUCTION

Onset age at menarche has been considered an important indicator of reproductive maturity in females and reflects the health status of the population. The purpose of this study was to determine the mean menarcheal age and to examine whether anthropometric and socio-economic status (SES) influences age at menarche in the girls from Punjab province of Pakistan.

METHODS

In this population-based cross-sectional study, 10,050 school-going girls aged 8-16 years from 35 schools across 12 districts of Punjab were recruited. Menarcheal data was obtained by using a questionnaire, while the anthropometric data were obtained by the measurements of standing height, body weight, waist, and hip circumference. The anthropometric indices of pre- and post-menarcheal girls were compared. Student's t-test, ANOVA, and post-hoc Tukey's test was applied for comparison between two and multiple groups respectively, P < 0.05 was considered statistically significant.

RESULTS

There was a normal distribution of age at menarche and mean was 12.4 years in the study population. The girls who reached menarche were found to be taller and heavier with higher BMIs, having a greater waist and hip circumference as compared to their pre-menarcheal peers. Waist-hip-ratio was less, and the waist-to-height ratio was higher in post-menarcheal as compared to pre-menarcheal girls. The girls belonging to low SES had delayed onset of menarche as compared to those belonging to middle/high SES.

CONCLUSION

The age at menarche was associated with SES and changes in various anthropometric measurements reflecting the growth status of girls.

Can the Neuromuscular Performance of Young Athletes Be Influenced by Hormone Levels and Different Stages of Puberty?

BACKGROUND

Endocrine mechanisms can be a determining factor in the neuromuscular performance of young athletes.

OBJECTIVE

The objective of the present study was to relate maturational and hormonal markers to neuromuscular performance, as well as to verify whether young athletes with different testosterone levels show differences in muscle strength.

METHODS

The sample consisted of 37 young male Brazilian athletes (11.3 ± 0.94 years) who were members of a sports initiation project. Hormonal markers were analyzed biochemically by blood samples, and maturation markers by mathematical models based on anthropometry. Body composition was verified by tetrapolar bioimpedance. The performance of upper and lower limb strength and body speed were analyzed.

RESULTS

Hormonal and maturational markers were related to neuromuscular performance (p < 0.05). Young people with higher testosterone levels showed higher muscle strength (p < 0.05). Artificial neural networks showed that testosterone predicted the performance of upper limbs by 49%, and maturation by 60%. Maturation foreshadowed the performance of lower limbs by 30.3%.

CONCLUSION

Biological maturation and hormonal levels can be related to neuromuscular performance, and young people with higher testosterone levels show superior muscle strength in relation to the others.