Pubertal Development

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.

Special considerations for the child with obesity: An Obesity Medicine Association (OMA) clinical practice statement (CPS) 2024

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) details assessment and management of the child with overweight or obesity. The term "child" is defined as the child between 2 and 12 years of age. Because children are in a continual state of development during this age range, we will specify when our discussion applies to subsets within this age range. For the purposes of this CPS, we will use the following definitions: overweight in the child is a body mass index (BMI) ≥ 85th and <95th percentile, obesity in the child is a BMI ≥95th percentile, and severe obesity is a BMI ≥120% of the 95th percentile.

Methods

The information and clinical guidance in this OMA Clinical Practice Statement are based on scientific evidence, supported by medical literature, and derived from the clinical perspectives of the authors.

Results

This OMA Clinical Practice Statement provides an overview of prevalence of disease in this population, reviews precocious puberty in the child with obesity, discusses the current and evolving landscape of the use of anti-obesity medications in children in this age range, discusses the child with obesity and special health care needs, and reviews hypothalamic obesity in the child.

Conclusions

This OMA Clinical Practice Statement on the child with obesity is an evidence based review of the literature and an overview of current recommendations. This CPS is intended to provide a roadmap to the improvement of the health of children with obesity, especially those with metabolic, physiological, psychological complications and/or special healthcare needs. This CPS addresses treatment recommendations and is designed to help the clinician with clinical decision making.

The scheduling of adolescence with Netrin-1 and UNC5C

Dopamine axons are the only axons known to grow during adolescence. Here, using rodent models, we examined how two proteins, Netrin-1 and its receptor, UNC5C, guide dopamine axons toward the prefrontal cortex and shape behaviour. We demonstrate in mice (Mus musculus) that dopamine axons reach the cortex through a transient gradient of Netrin-1-expressing cells - disrupting this gradient reroutes axons away from their target. Using a seasonal model (Siberian hamsters; Phodopus sungorus) we find that mesocortical dopamine development can be regulated by a natural environmental cue (daylength) in a sexually dimorphic manner - delayed in males, but advanced in females. The timings of dopamine axon growth and UNC5C expression are always phase-locked. Adolescence is an ill-defined, transitional period; we pinpoint neurodevelopmental markers underlying this period.

The scheduling of adolescence with Netrin-1 and UNC5C

Dopamine axons are the only axons known to grow during adolescence. Here, using rodent models, we examined how two proteins, Netrin-1 and its receptor, UNC5C, guide dopamine axons towards the prefrontal cortex and shape behaviour. We demonstrate in mice ( Mus musculus ) that dopamine axons reach the cortex through a transient gradient of Netrin-1 expressing cells - disrupting this gradient reroutes axons away from their target. Using a seasonal model (Siberian hamsters; Phodopus sungorus ) we find that mesocortical dopamine development can be regulated by a natural environmental cue (daylength) in a sexually dimorphic manner - delayed in males, but advanced in females. The timings of dopamine axon growth and UNC5C expression are always phase-locked. Adolescence is an ill-defined, transitional period; we pinpoint neurodevelopmental markers underlying this period.

Reproductive justice in pediatric health care: a scoping review protocol

OBJECTIVE

The objective of this scoping review is to identify the barriers and facilitators of reproductive justice in pediatric health care.

INTRODUCTION

Reproductive justice is defined as the right to maintain personal bodily autonomy, to have or not have children, and to parent children in safe and sustainable communities. The reproductive justice framework is often applied to adult women in conventional care settings; however, the need for health care guided by the framework should extend to all females of reproductive age in all care settings, including pediatric settings.

INCLUSION CRITERIA

This review will consider studies from 1994 to the present that report on the barriers and facilitators of reproductive justice in pediatric health care. Studies from any setting or geographic location will be included. This scoping review will include pediatric patients up to 21 years of age of any gender identity or sexual orientation who may birth a child, and their health care providers.

METHODS

Database searches will include CINAHL (EBSCOhost), MEDLINE (PubMed), Embase (Elsevier), and Web of Science Core Collection. Sources of unpublished studies and gray literature to be searched include MedNar and ProQuest Dissertation and Theses Science and Engineering Collection (ProQuest). The JBI methodology for scoping reviews will be followed. Data extracted will include details about the title, authors, year of publication, type of evidence, participants, context, and concept. The extracted data will be presented in diagrammatic or tabular format in a manner that aligns with the objective and questions of the scoping review.

REVIEW REGISTRATION

Open Science Framework https://osf.io/d5vf9.

Maturation of the Female Pharyngeal Airway from Adolescence to Adulthood

BACKGROUND

The present study aimed to investigate developmental changes in the female pharyngeal airway from adolescence to adulthood, considering variations in the anatomical structures related to the airway dimensions.

METHODS

Lateral cephalograms of 214 females were analyzed and categorized into five developmental stages: early adolescence (10-13 years), middle adolescence (14-17 years), late adolescence (18-21 years), early adulthood (22-30 years), and middle adulthood (31-50 years). The focus of the analysis included the point A-Nasion-point B (ANB) angle, tongue pharyngeal airway space (TPS), epiglottis pharyngeal airway space (EPS), soft palate airway space (SPS), and the horizontal and vertical positions of the hyoid bone.

RESULTS

The ANB angle exhibited significant variation across groups, being significantly larger in the early-adolescence group (4.22°) compared to the middle-adolescence, late-adolescence, and early-adulthood groups. The TPS and EPS were significantly shorter in the early-adolescence group. Negative correlations were observed between the ANB angle and the lengths of the pharyngeal airway spaces (SPS, TPS, and EPS). The horizontal and vertical positions of the hyoid bone remained stable after middle adolescence.

CONCLUSION

The maturation of the ANB angle and pharyngeal airway in females seems nearly completed during middle adolescence (14-17 years). Additionally, a significant and negative correlation was identified between the ANB angle and the lengths of various pharyngeal airway spaces (SPS, TPS, and EPS). The horizontal and vertical positions of the hyoid bone showed stability after middle adolescence.

Unique considerations for the medical care of restrictive eating disorders in children and young adolescents

BACKGROUND

The medical complications of eating disorders are often approached through an age-neutral lens. However, children and young adolescents may have unique medical complications related to the energy needs and timing of growth and development. Providers caring for patients in this vulnerable age range should understand how to identify, approach, and manage these potential age-related complications.

REVIEW

Evidence continues to accumulate that increasingly younger patients are being diagnosed with eating disorders. These children and young adolescents have significant risk for unique and potentially irreversible medical complications. Without early identification and treatment, restrictive eating disorders may negatively impact linear growth, bone development and brain maturation in children and young adolescents. Additionally, due to the energy needs of growth and development, unique considerations exist for the use of acute medical stabilization and the identification of patients at risk for refeeding syndrome with initial nutritional rehabilitation. This review presents an approach to the evaluation and management of children and young adolescents with eating disorders.

CONCLUSION

Children and young adolescents with restrictive eating disorders may have unique medical complications related to the energy needs and timing of linear growth and pubertal development. Significant risk exists for irreversible medical complications of impaired growth, bone, and brain health. Increased awareness of the energy needs for growth and development may improve early recognition, appropriate intervention, and future outcomes for children and young adolescents with restrictive eating disorders.

Physical Development and Puberty in Related Patients with Kindler Epidermolysis Bullosa: Case Study

Background. Kindler epidermolysis bullosa is orphan, autosomal recessive disease and it is one of the variants of congenital epidermolysis bullosa. Its severe course is characterized by high risk of multifactorial malnutrition, chronic inflammation due to recurrent secondary skin infections, and also bone metabolism disorders, what can lead to disorders in physical development and puberty in children. However, the effect of Kindler epidermolysis bullosa on patients’ physical development and puberty remains unexplored.

Clinical case description. Family case of Kindler epidermolysis bullosa was presented in 13 and 12 years old patients, third degree of kinship (maternal, uncle — nephew) with typical clinical manifestations for this disease. The diagnosis was confirmed in both patients via Sanger sequencing and revealing identical pathogenic variants in the FERMT1 gene (two deletions in the compound-heterozygous state — c.778del, p.Q260Kfs*21 and c.1088del, p. L363Wfs*39). Reduced concentrations of testosterone and 25(OH)D were revealed, whereas, increased concentration of adrenocorticotropic hormone — only in the older patient. The concentrations of luteinizing hormone, follicle-stimulating hormone and estradiol in both patients were within the reference values. The younger patient had prepubertal sizes and volume of testicles. Both patients had specific features of psychoemotional state: mood swing with rapid increase in anxiety level in the older patient and difficulties in emotional-volitional regulation in younger one.

Conclusion. Patients with Kindler epidermolysis bullosa have high risk of physical development and puberty delay due to its systemic chronic pathological process. Thus, these patients require dynamic follow-up by pediatrician and pediatric endocrinologist.

Growth, maturation and injuries in high-level youth football (soccer): A mini review

Understanding the challenges football (soccer) players face during adolescence is fundamental to avoid disruptions in their development due to injury. This mini review will describe basic concepts of somatic growth and biological maturity, examine data from 53 prospective epidemiological studies on high-level youth football players and discuss how age, growth and maturity may affect the injury patterns observed. Based on the existing evidence, at least every third player sustains an injury during a football season. The thigh (median for studies of boys: 25%, median for girls: 21%), ankle (b: 18%, g: 30%), knee (b: 17%, g: 18%) and hip/groin (b: 14%, g: 10%) are the body parts injured most often, while muscle strains (b: 31%, g: 25%), sprains (b: 20%, g: 27%) and contusions (b: 17%, g: 16%) are the most common injury types. Injury trends are, however, not consistent throughout adolescence, and players' age, maturity status and position relative to peak height velocity (PHV) have shown to influence the number, type and location of injuries sustained. Despite a high volume of observational injury studies published on high-level youth players, girls (7 studies) and settings outside of Europe (included in 23% of studies) are underrepresented and should receive extra attention in the future. Based on the available epidemiological data, tailored injury reduction programmes can be considered in youth football, alongside application of general training principles such as progression, variation and individualization which may be especially important during vulnerable phases such as the adolescent growth spurt.

Linking Puberty and the Gut Microbiome to the Pathogenesis of Neurodegenerative Disorders

Puberty is a critical period of development marked by the maturation of the central nervous system, immune system, and hypothalamic-pituitary-adrenal axis. Due to the maturation of these fundamental systems, this is a period of development that is particularly sensitive to stressors, increasing susceptibility to neurodevelopmental and neurodegenerative disorders later in life. The gut microbiome plays a critical role in the regulation of stress and immune responses, and gut dysbiosis has been implicated in the development of neurodevelopmental and neurodegenerative disorders. The purpose of this review is to summarize the current knowledge about puberty, neurodegeneration, and the gut microbiome. We also examine the consequences of pubertal exposure to stress and gut dysbiosis on the development of neurodevelopmental and neurodegenerative disorders. Understanding how alterations to the gut microbiome, particularly during critical periods of development (i.e., puberty), influence the pathogenesis of these disorders may allow for the development of therapeutic strategies to prevent them.

Developmental cascades and educational attainment

Developmental cascades describe how systems of development interact and influence one another to shape human development across the lifespan. Despite its popularity, developmental cascades are commonly used to understand the developmental course of psychopathology, typically in the context of risk and resilience. Whether this framework can be useful for studying children's educational outcomes remains underexplored. Therefore, in this chapter, we provide an overview of how developmental cascades can be used to study children's academic development, with a particular focus on the biological, cognitive, and contextual pathways to educational attainment. We also provide a summary of contemporary statistical methods and highlight existing data sets that can be used to test developmental cascade models of educational attainment from birth through adulthood. We conclude the chapter by discussing the challenges of this research and explore important future directions of using developmental cascades to understand educational attainment.

Body composition in individuals with cystic fibrosis

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

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

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

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

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

Adolescent Gynecology in the Office Setting

Ensuring open communication, partnership with patient and parent, and clarification of confidentiality during an adolescent gynecologic visit helps establish an environment in which a history and physical examination can be performed safely and with a focus on prevention, recognition of disease, and treatment as necessary. The history should include the menstrual status and gynecologic review of systems. The examination should document Tanner staging (sexual maturity rating) and be otherwise symptom guided. Similarly, testing in the office is largely risk and symptom related. Contraceptive counseling is an important component of the office visit, as well. Long and short curricula for teaching pediatric and adolescent gynecology have been developed by the North American Society for Pediatric and Adolescent Gynecology and are readily available for use. (1)(2) Although state-based variation in consent and confidentiality exists, pediatric practices should aim to protect patient confidentiality and transition to more independent health-care decision making.

Fat Mass Accretion from Birth to 5 Years and Metabolic Homeostasis in Childhood: the Healthy Start Study

CONTEXT

It is unclear how fat mass accretion in early life is related to glucose-insulin homeostasis.

OBJECTIVE

Examine associations of fat and fat-free mass accretion from birth to early childhood with glucose-insulin homeostasis in early childhood in a multi-ethnic cohort.

METHODS

Observational Healthy Start study with data collection from 2010 to 2020. Air displacement plethysmography at birth and 4.8 (SD 0.7) years estimated fat mass percent (FMP, %), fat mass index (FMI, kg/m2), and fat-free mass index (FFMI, kg/m2). General population recruited from academic obstetrics clinics in Denver, Colorado, consisting of 419 mother/offspring dyads. The main outcome measures were fasting glucose, insulin, homeostasis model assessment-2 insulin resistance (HOMA2-IR), and beta-cell function (HOMA2-B) at 4.8 years.

RESULTS

Greater fat mass accretion from birth to early childhood was associated with higher fasting glucose (ΔFMP β = 0.20 [95% CI 0.06-0.34], ΔFMI β = 0.90 [0.30-1.50]) in participants of Hispanic, Black, and Other races/ethnicities, while greater fat-free mass accretion was associated with higher fasting glucose in non-Hispanic White participants (ΔFFMI β = 0.76 [0.21-1.32]). Overall, greater fat, but not fat-free, mass accretion was also associated with higher insulin (ΔFMP β = 0.14 [0.09-0.18], ΔFMI 0.71 [0.51-0.92]), HOMA2-IR (FMP β = 0.02 [0.01-0.02], ΔFMI β = 0.09 [0.06-0.12]), and HOMA2-B (ΔFMP β = 0.92 [0.18-1.36], ΔFMI β = 4.76 [2.79-6.73]).

CONCLUSION

Greater fat mass accretion in infancy and childhood is associated with shifts in fasting glucose in children of Hispanic, Black, and Other races/ethnicities at 5 years of age. Body composition beginning in early life is relevant for metabolic health, and precise assessments of adiposity in pediatric research are needed.

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.

Energy intake and expenditure in children and adolescents, contributions of biological maturity

OBJECTIVE

The aim of this study was to examine the relationship between the ratio of energy intake (EI) and energy expenditure (EE) and body composition, physical activity and macronutrients intake, considering maturity as a moderator.

METHODS

The study involved 459 adolescents aged 10 to 17. Energy and macronutrients intake were estimated using a valid Food Frequency Questionnaire; basal metabolic rate (BMR) was predicted from Schofield equations and EE was estimated using BMR and physical activity level obtained through a Portuguese validated biosocial questionnaire. Body mass index, body composition, and bone age were objectively measured. Statistical analyses included independent samples t-tests, ANCOVA and Pearson correlations. All analyses were adjusted for chronological age, sex, and EI.

RESULTS

Body mass index, fat and fat-free mass, physical activity and protein intake were negatively correlated with EI/EE (P < .001). The study showed significant interactions between maturity and body mass index, fat-free mass and physical activity level. Maturity attenuated the negative relationships between EI/EE and body mass index, fat-free mass and physical activity, especially among early maturers. All categories of maturity showed implications in body mass index for values lower than 23.8 kg/m² . A significant EI/EE reduction was observed among late maturers with a fat-free mass above 39.8 kg.

CONCLUSIONS

Our findings suggest that maturity moderates the relationship between EI/EE and body mass index, fat-free mass and physical activity, especially evident among late maturers.

Delayed menarche in girls with chronic kidney disease and the association with short stature

BACKGROUND

Children with chronic kidney disease (CKD) have delays in normal growth and pubertal development. We describe factors associated with delayed menarche and the association of delayed menarche with short stature in girls with CKD.

METHODS

Two hundred eighty-seven girls with CKD onset prior to menarche within the Chronic Kidney Disease in Children (CKiD) cohort were studied. Delayed menarche was defined as menarche at age 15 years or older; short stature was defined as last available height 2 standard deviations below projected adult height. Kaplan-Meier cumulative incidence function was used to estimate median age at menarche. Chi-squared and Wilcoxon rank-sum tests were used to assess factors associated with delayed menarche. Chi-squared test was used to evaluate the association between delayed menarche and short stature.

RESULTS

Among 287 girls, 68 enrolled with prevalent menarche, 131 were observed to have incident menarche, and 88 were pre-menarchal at their last study visit. Median age at menarche was 12 years. Ten percent had delayed menarche. African American race, lower estimated glomerular filtration rate, ever corticosteroid use, and longer CKD duration were associated with delayed menarche (p < 0.05). Girls with delayed menarche had lower height and weight percentiles at the time of menarche (p < 0.05). Sixty-one percent of girls with delayed menarche had short stature compared with only 35% of girls without delayed menarche (p = 0.03).

CONCLUSION

Median age at menarche is similar among girls with CKD and healthy girls. Ten percent of girls with CKD had delayed menarche and may be at risk for short stature.

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

Despite increasing global attention to adolescent health in low- and middle-income countries (LMICs), limited literature exists on the timing of pubertal development in these settings. This study aimed to determine the age at menarche (AAM) and age of puberty onset [female Tanner Stage Breast 2 (B2) and male Tanner Stage Genital 2 (G2)] among healthy adolescents living in LMICs. It also aimed to explore the impact of nutritional status on pubertal timing in this population. MEDLINE, Embase, Cochrane CENTRAL, Web of Science, Scopus, and grey literature databases were searched. Observational studies and control arms of randomized controlled trials (RCTs) with healthy participants from LMICs born in or after 1998 were included. Pooled estimates with 95% CIs were calculated by random-effects meta-analyses using the DerSimonian and Laird inverse variance method for each pubertal milestone and by BMI category subgroups. Twenty-seven studies were included in the meta-analysis, representing 90,188 adolescents (78.3% female). Pooled mean estimates for AAM for normal, thin, and overweight BMI groupings were 12.3 y (95% CI: 12.1, 12.5), 12.4 y (95% CI: 12.2, 12.6), and 12.1 y (95% CI: 11.7, 12.5), respectively. For Tanner Stage B2, pooled mean age estimates for normal, thin, and overweight BMI groupings were 10.4 y (95% CI: 9.2, 11.6), 10.2 y (95% CI: 9.3, 11.4), and 8.4 y (95% CI: 6.8, 10.0), respectively. Finally, for Tanner Stage G2, pooled mean estimates for normal, thin, and overweight BMI groupings were 11.0 y (95% CI: 10.3, 11.7), 11.3 y (95% CI: 9.8, 12.9), and 10.3 y (95% CI: 10.0, 10.6), respectively. Data on the timing of pubertal milestones has traditionally come from high-income settings. In this systematic review of contemporary data from adolescents in LMICs, AAM, as well as age at pubertal onset, were similar to those reported from high-income settings.

Sex as a moderator of body composition following a randomized controlled lifestyle intervention among Latino youth with obesity

BACKGROUND

Body composition differences between males and females emerge during adolescence and continue throughout adulthood; however, whether sex moderates body composition changes in adolescents with obesity after an intervention is unknown.

OBJECTIVE

To examine sex as a moderator of changes in adiposity following lifestyle intervention.

METHODS

A total of 136 Latino youth with obesity (BMI% 98.2 ± 1.3) aged 14 to 16 years old were randomized to either a 12-week lifestyle intervention (27 males/40 females) or control (35 males/34 females) group. The intervention included nutrition education (1 h/wk) and moderate-to-vigorous physical activity (3 h/wk). Anthropometric data (body mass index [BMI], BMI%, waist circumference, total body fat, and fat-free mass) were obtained pre- and post-intervention. Sex differences were examined by general linear models with significance determined at P < .05 for the F-statistic.

RESULTS

Sex did not moderate changes in BMI (F1,115 = 0.01, P = .9), BMI% (F1,115 = 0.14, P = .7), or waist circumference (F1,117 = 1.1, P = .3). Sex significantly moderated changes in body fat percent (F1,117 = 5.3, P = .02), fat mass (F1,116 = 4.5, P = .04), and fat-free mass (F1,116 = 4.3, P = .04). Intervention males compared with females had greater relative reductions in fat percent (-4.1 ± 0.8% vs -1.2 ± 0.7%, P = .02) and fat mass (-5.0 ± 1.1 kg vs -1.5 ± 0.9 kg, P = .02) and gained more fat free mass (3.6 ± 0.9 kg vs 0.5 ± 0.8 kg, P = .02) when compared with same sex controls.

CONCLUSION

Males and females exhibited a differential response to lifestyle intervention for percent fat, fat mass, and fat-free mass indicating that sex-specific improvements in body composition favours males over females.

Progesterone and Breast Cancer

Synthetic progestogens (progestins) have been linked to increased breast cancer risk; however, the role of endogenous progesterone in breast physiology and carcinogenesis is less clearly defined. Mechanistic studies using cell culture, tissue culture, and preclinical models implicate progesterone in breast carcinogenesis. In contrast, limited epidemiologic data generally do not show an association of circulating progesterone levels with risk, and it is unclear whether this reflects methodologic limitations or a truly null relationship. Challenges related to defining the role of progesterone in breast physiology and neoplasia include: complex interactions with estrogens and other hormones (eg, androgens, prolactin, etc.), accounting for timing of blood collections for hormone measurements among cycling women, and limitations of assays to measure progesterone metabolites in blood and progesterone receptor isotypes (PRs) in tissues. Separating the individual effects of estrogens and progesterone is further complicated by the partial dependence of PR transcription on estrogen receptor (ER)α-mediated transcriptional events; indeed, interpreting the integrated interaction of the hormones may be more essential than isolating independent effects. Further, many of the actions of both estrogens and progesterone, particularly in "normal" breast tissues, are driven by paracrine mechanisms in which ligand binding to receptor-positive cells evokes secretion of factors that influence cell division of neighboring receptor-negative cells. Accordingly, blood and tissue levels may differ, and the latter are challenging to measure. Given conflicting data related to the potential role of progesterone in breast cancer etiology and interest in blocking progesterone action to prevent or treat breast cancer, we provide a review of the evidence that links progesterone to breast cancer risk and suggest future directions for filling current gaps in our knowledge.

Nash-wo-Numa (childhood growth & development) study protocol: factors that impact linear growth in children 9 to 15 years of age in Matiari, Pakistan

INTRODUCTION

Adolescence is a time of significant physical and emotional change, and there is emerging concern that adolescents living in low- and middle-income countries (LMIC) may face substantial challenges in relation to linear growth and mental health. Data on the global burden of stunting after 5 years of age are limited, but estimates suggest up to 50 per cent of all adolescents in some LMIC are stunted. Additionally, many LMIC lack robust mental health care delivery systems. Pakistan has one of the world's largest populations of adolescents (10 to 19 years) at approximately 40 million. The Nash-wo-Numa study's primary objective is to assess the prevalence and risk factors for stunting among early adolescents in rural Pakistan. The study also aims to determine the prevalence of poor mental health and identify factors associated with common mental health concerns during the childhood to adulthood transition.

METHODS

This cross-sectional study will include girls (n= 738) 9.0 to 14.9 years of age and boys (n=687) 10.0 to 15.9 years of age who live in the rural district of Matiari, Pakistan. Participants will be assessed for anthropometrical measures, puberty development, nutritional biomarkers as well as symptoms of depression, anxiety and trauma using validated scales.

ETHICS AND DISSEMINATION

The proposed study aims to complete the picture of child and adolescent health concerning linear growth and mental health by including puberty indicators. Ethics approval has been granted by the Ethics Review Committee at the Aga Khan University, Karachi, Pakistan, #5251-WCH-ERC-18 and Research Ethics Board at SickKids Hospital, Toronto, Canada, #:1000060684. Study results will be presented at relevant conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03647553; Pre-results.

Manganese exposure and association with hormone imbalance in children living near a ferro-manganese alloy plant

It has been suggested that manganese (Mn) plays a fundamental role in the reproductive system through interference with the regulation of the secretion of hormones related to puberty. The objective of this study was to evaluate the environmental exposure to Mn and its effects on the endocrine regulation of hormones related to puberty in school-aged children living near a ferro-manganese alloy plant. Toenails, occipital hair, and blood samples were collected from 225 children, between 7 and 12 years of age, in four elementary schools in Simões Filho, Bahia, Brazil, who were exposed to different Mn levels owing to different Mn dust deposition rates. The Mn content was determined in the toenails (MnTn), hair (MnH), and blood (MnB), in addition to blood lead levels (PbB), by using graphite furnace atomic absorption spectrometry. Luteinizing hormone (LH), prolactin (PRL), estradiol (E₂), testosterone (T), and thyroid stimulating hormone (TSH) levels were determined by using a chemiluminescence method. Of the total participants, 50.2% were boys, with an average age of 9 years. PRL values were higher in children attending the school with a higher Mn deposition rate (p < 0.004). We observed that MnTn was positively correlated with PRL levels and exhibited a non-linear association with LH levels. None of the tested Mn biomarkers were associated with E₂, T, or TSH levels. To date, despite several animal studies that have focused on the correlation between Mn exposure and the endocrine regulation of hormones and pubertal development, very few studies have reported a similar relationship between environmental Mn effects and the human endocrine system. Our findings support the hypothesis that elevated exposure to Mn in children may be associated with hormonal imbalances that might trigger the early onset of puberty.

11-year old boy with facial hair, acne and deepened voice

11-year old twin boy found to have idiopathic precocious puberty after routine well-child examination revealed discordant pubertal growth between the two brothers.

Determination of Pubertal Status in Youths With Type 1 Diabetes Using Height Velocity and Trajectories

CONTEXT

Assessment of pubertal change is important for the management of chronic pediatric diseases, such as type 1 diabetes. Physical and/or laboratory assessments of pubertal status are often unavailable, impractical, or costly.

OBJECTIVE

To develop and validate a practical and objective method to assess pubertal status using longitudinal linear growth in youths with type 1 diabetes.

DESIGN, PARTICIPANTS, AND OUTCOME MEASUREMENTS

Participants (n = 123) were part of a 2-year study assessing continuous glucose monitoring in youths with type 1 diabetes at a tertiary diabetes center. Pubertal status at visits was assigned by a tiered approach using clinical Tanner staging or indicators of pubertal maturation from the electronic medical record when available. For other visits, independent evaluations of height velocities and growth chart trajectories provided data for pubertal status assignments. Sensitivity analysis confirmed the validity of the pubertal status assignments.

RESULTS

The sample (50% female, 95% white) had a mean ± SD age of 12.7 ± 2.7 years, diabetes duration of 6.0 ± 3.6 years, and hemoglobin A1c of 7.9 ± 0.8%. Of 985 study visits, 50% received a pubertal status assignment based on clinical Tanner staging, 29% on additional medical record review, and 22% on an evaluation of height velocity and growth chart trajectory. For the sensitivity analysis, pubertal status assignments based on height velocity and growth chart trajectory matched clinical Tanner staging in 87% of visits.

CONCLUSIONS

Our practical and objective method to assess pubertal status based on height velocity and growth chart trajectory highlights growth as a reliable and objective bioassay for pubertal onset, status, and progression.

Malocclusion and maxillofacial characteristics of young girls having precocious puberty

AIM

This study aimed to evaluate the dentofacial characteristics and need for orthodontic treatment in young girls having precocious puberty (PP).

DESIGN

It was a cross-sectional study that included 39 girls, age ranging from 6 to 11 years old, with confirmed diagnosis of PP. The Dental Aesthetic Index (DAI) and the Index of Orthodontic Treatment Need (IOTN) were used to assess malocclusion and the need for orthodontic treatment, and cephalometric analysis was used for the diagnosis of facial growth abnormalities. Data analysis included descriptive statistics and one-sample t-test.

RESULTS

Findings revealed high prevalence (64.1%) of severe and very severe malocclusion (DAI grades 3-4), and 82.1% of cases were classified as having moderate to high treatment need (IOTN grades 3-4). All linear cephalometric measures and most of the angular parameters differed significantly from the reference values, indicating a tendency for Class II molar relationship. There was a high proportion of the sample outside the reference value limits, ranging from 79.5% of cases below the reference limits for facial height to 59.0% of cases above the limits for incisor-mandibular plane angle.

CONCLUSIONS

Results suggest that dental and craniofacial development may be associated with PP in young girls, which may be considered in the diagnosis and treatment decisions for orthopaedic/orthodontic intervention.