Assessing pubertal status in multi-ethnic primary schoolchildren

Temporal relation between pubertal development and peer victimization in a prospective sample of US adolescents

Peer victimization typically peaks in early adolescence, leading researchers to hypothesize that pubertal timing is a meaningful predictor of peer victimization. However, previous methodological approaches have limited our ability to parse out which puberty cues are associated with peer victimization because gonadal and adrenal puberty, two independent processes, have either been conflated or adrenal puberty timing has been ignored. In addition, previous research has overlooked the possibility of reverse causality-that peer victimization might drive pubertal timing, as it has been shown to do in non-human primates. To fill these gaps, we followed 265 adolescents (47% female) prospectively across three-time points (Mage : T1 = 9.6, T2 = 12.0, T3 = 14.4) and measured self-report peer victimization and self- and maternal-report of gonadal and adrenal pubertal development on the Pubertal Development Scale. Multilevel modeling revealed that females who were further along in adrenal puberty at age 9 were more likely to report peer victimization at age 12 (Cohen's d = 0.25, p = .005). The relation between gonadal puberty status and peer victimization was not significant for either sex. In terms of the reverse direction, the relation between early peer victimization and later pubertal development was not significant in either sex. Overall, our findings suggest that adrenal puberty status, but not gonadal puberty status, predicted peer victimization in females, highlighting the need to separate gonadal and adrenal pubertal processes in future studies.

Infant effortful control predicts BMI trajectories from infancy to adolescence

BACKGROUND

Effortful control, or the regulation of thoughts and behaviour, is a potential target for preventing childhood obesity.

OBJECTIVES

To assess effortful control in infancy through late childhood as a predictor of repeated measures of body mass index (BMI) from infancy through adolescence, and to examine whether sex moderates the associations.

METHODS

Maternal report of offspring effortful control and measurements of child BMI were obtained at 7 and 8 time points respectively from 191 gestational parent/child dyads from infancy through adolescence. General linear mixed models were used.

RESULTS

Effortful control at 6 months predicted BMI trajectories from infancy through adolescence, F(5,338) = 2.75, p = 0.03. Further, when effortful control at other timepoints were included in the model, they added no additional explanatory value. Sex moderated the association between 6-month effortful control and BMI, F(4, 338) = 2.59, p = 0.03, with poorer infant effortful control predicting higher BMI in early childhood for girls, and more rapid increases in BMI in early adolescence for boys.

CONCLUSIONS

Effortful control in infancy was associated with BMI over time. Specifically, poor effortful control during infancy was associated with higher BMI in childhood and adolescence. These findings support the argument that infancy may be a sensitive window for the development of later obesity.

The Effect of Neighborhood-level Resources on Children's Physical Development: Trajectories of Body Mass Index and Pubertal Development and the Influence of Child Biological Sex

Growing research substantiates the role of neighborhood disadvantage in contributing to early pubertal maturation and higher body mass index; however, previous studies in this area have design limitations. Specifically, many studies have been cross-sectional, have used singular indicators of neighborhood disadvantage (e.g., poverty), and have provided mixed findings about the role of biological sex. The present study addresses these gaps by examining how neighborhood resources (spanning educational, health/environmental, and social/economic domains) predict trajectories of pubertal maturation and body mass index using longitudinal multi-wave data. Furthermore, multigroup analyses assessed how these associations may differ by child biological sex. Participants in this study (n = 505; 54% male) were assessed every 3 years at age 9 (M = 9.17, SD = 0.39), age 12 (M = 12.63, SD = 0.43), and age 15 (M = 15.23, SD = 0.37). Approximately 12% of the sample identified as Hispanic, and 11% as non-White. Using multigroup latent growth analyses, the study examined how neighborhood resources predicted trajectories of pubertal maturation and body mass index using multi-wave data across middle childhood through mid-adolescence. The findings suggested that greater neighborhood resources were cross-sectionally associated with lower pubertal development and predicted slower trajectories across time. Although all girls in the study eventually progressed through pubertal development, girls in lower resourced neighborhoods experienced a much earlier onset of puberty. Additionally, greater neighborhood resources predicted lower BMI both cross sectionally and longitudinally. Specifically, higher resourced neighborhoods were protective against obesity risk for both boys and girls across mid-childhood through mid-adolescence. In sum, the study highlights the role of broader neighborhood factors on early maturity risk for female children, and obesity risk for children regardless of biological sex.

Effects of a School-Based Physical Activity Intervention for Obesity and Health-Related Physical Fitness in Adolescents With Intellectual Disability: Protocol for a Randomized Controlled Trial

BACKGROUND

Childhood obesity accompanied by lower levels of health-related physical fitness (HRPF) is a major threat to public health both internationally and locally. Children with intellectual disability, especially adolescents, have a higher risk of being overweight/obese and having poor HRPF levels. Therefore, more interventions are needed to help this population attain their optimal health levels. However, there has been relatively limited research on this population compared with on their typically developing peers.

OBJECTIVE

The proposed study aims to fill this knowledge gap by developing and examining the success of a physical activity (PA) intervention for the target population.

METHODS

The proposed study will be a 12-week, school-based randomized controlled trial. The participants (N=48) will be recruited from special schools for students with mild intellectual disability and then randomly allocated to either the intervention group (IG) or the wait-list control group (CG). During the intervention period, the participants in the IG will receive a fun game-based moderate-to-vigorous PA (MVPA) training program (2 sessions/week, 60 minutes/session, for a total of 24 sessions). The intensity of the activities will increase in a progressive manner. Participants in the CG will receive no program during the study period, but the same PA program will be provided to them after the completion of the study. To observe and evaluate the sustaining effects of the intervention, follow-up testing will be scheduled for the participants 12 weeks after the intervention concludes. The study outcomes will include primary outcomes (obesity- and fitness-related outcomes) and a secondary outcome (blood pressure). All of the measurements will be taken at 3 time points. After the follow-up tests, the same PA training program will be provided to the participants in the CG.

RESULTS

This study is ongoing. The participants were recruited from October 2020 to November 2020. The total duration of the study is 13 months. Study results are expected at the end of 2021.

CONCLUSIONS

The proposed study is expected to reduce obesity and improve HRPF levels in children with intellectual disability. If proven effective, the intervention will be made accessible to more special schools and mainstream schools with students with intellectual disability. Furthermore, the study can serve as an example for international researchers, policy makers, and members of the public who are seeking to tackle the problem of obesity and poor HRPF among children with intellectual disability.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04554355; https://www.clinicaltrials.gov/ct2/show/NCT04554355.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/25838.

Carotid Intima-Media Thickness in Healthy Children and Adolescents: Normative Data and Systematic Literature Review

Objectives: Early identification of children at risk of atherosclerosis is of paramount importance for implementing primary preventive measures addressing vascular health. Carotid intima-media thickness (cIMT) is a non-invasive biomarker of atherosclerosis. Semiautomatic radiofrequency-based software-guided technique quality intima-media thickness (RF-QIMT) was used to determine cIMT normative values in a healthy cohort of Caucasian children aged 6 to 18 years.

Study design: In a cross-sectional study, data on age, chronic illness, medication use, and pubertal status was acquired by a questioner. Anthropometric and blood pressure measurements were performed by standardized methods and trained medical personnel. cIMT of the right common carotid artery far wall (1 centimeter proximal to bifurcation) was determined using a multifrequency (3–13 MHz) electronic linear array transducer SL1543, a portable ultrasound device (MyLab Gamma Esaote, Genoa, Italy), and RF-QIMT software. A systematic review of the published normal cIMT in children was done using PRISMA methodology, and identified normative values were compared to those obtained in the presented study.

Results: 1137 non-obese normotensive children (males: n = 512; mean age 12.04 ± 3.52 years, females: n = 625, mean age 12.98 ± 3.83 years) were included. Gender-, age-, and height-specific mean cIMT percentile tables, percentile charts, and LMS tables for the RF-QIMT method were provided. They were comparable to the previously published data on mean cIMT gained by other validated ultrasound imaging techniques. cIMT increased with age, height, hip circumference, and BMI and was higher in males.

Conclusions: Gender-, age-, and height-specific normative cIMT values, using the semiautomatic software-guided RF-QIMT technique, in children aged 6 to 18 years were developed and validated in respect to the previously published pediatric normative cIMT data. It is suggested that the investigated method could be used for the estimation of atherosclerotic risk in children, especially in epidemiological studies.

Skeletal maturation in relation to ethnic background in children of school age: The Generation R Study

Ethnicity is a well-established determinant of pediatric maturity, but the underlying genetic and environmental contributions to these ethnic differences are poorly comprehended. We aimed to evaluate the influence of ethnicity on skeletal age (SA), an assessment of pediatric maturation widely used in clinical settings. We included children from the Generation R Study, a multiethnic population-based pregnancy cohort, assessed at a mean age of 9.78 (±0.33) years. SA was evaluated by a trained observer on hand DXA scans using the Greulich and Pyle method. Ethnic background was defined as geographic ancestry (questionnaire-based assessment) (N = 5325) and genetic ancestry (based on admixture analysis) (N = 3413). Associations between the ethnic background and SA were investigated separately in boys and girls, using linear regression models adjusted for age, height and BMI. Based on geographic ancestry, 84% of the children were classified as European, 6% as Asian and 10% as African. Children of European background had on average younger SA than those of Asian or African descent. Asian boys had 0.46 (95% CI 0.26-0.66, p-value < 0.0001) and African boys 0.36 years (95% CI 0.20-0.53, p-value < 0.0001) older SA as compared to European boys. Similarly, Asian girls showed 0.64 (95% CI 0.51-0.77, p-value < 0.0001) and African girls 0.38 years (95% CI 0.27-0.48, p-value < 0.0001) older SA as compared to European girls. A similar pattern was observed in the analysis with genetically-defined ancestry. Furthermore, an increase in the proportion of Asian or African component was associated with older SA in both boys (log[Non-European/European]proportion = 0.10, 95% CI 0.06-0.13, p-value < 0.0001) and girls (log[Non-European/European]proportion = 0.06, 95% CI 0.04-0.08, p-value < 0.0001). In summary, children of Asian and African backgrounds have on average older SA as compared to children of European descent, partially explained by a genetic component.

Methods for determining pubertal status in research studies: literature review and opinions of experts and adolescents

In lifecourse studies that encompass the adolescent period, the assessment of pubertal status is important, but can be challenging. We aimed to identify current methods for pubertal assessment and assess their appropriateness for population-based research by combining a review of the literature with the views of experts in the field. We searched bibliographic databases, extracted data and assessed study quality to inform a workshop with 21 experts. Acceptability of different approaches was explored with a panel of ten adolescents. We screened 11,935 abstracts, assessed 157 articles and summarised results from 38 articles. Combining these with the opinions of experts, self-assessment was found to be a practical method for use in studies where agreement with the gold standard of clinical assessment by physical examination to within one Tanner stage was acceptable. Serial measures of height and foot size accurately indicated timing of the pubertal growth spurt and age at peak height velocity, and were seen as feasible within longitudinal studies. Hormonal and radiological methods did not offer a practical means of assessing pubertal status. Assessment of voice maturation was promising, but needed validation. Young people thought that self-assessment, foot size and voice assessments were acceptable, and preferred an assessor of the same sex for clinical assessment. This review thus informs researchers working in lifecourse and adolescent health, and identifies future directions in order to improve validity of the methods.

Next Steps in Puberty Research: Broadening the Lens Toward Understudied Populations

Decades of puberty research have yielded key scientific discoveries. Building on the field's rich history, we highlight four understudied populations: youth of color, boys, sexual minority youth, and gender minority youth. We explore why scientific study has been slow to evolve in these groups and propose paths forward for exciting new work. For ethnically racially diverse youth, we discuss the need to incorporate culture and context. For boys, we highlight methodological issues and challenges of mapping existing conceptual models onto boys. For sexual and gender minority youth, we discuss unique challenges during puberty and suggest ways to better capture their experiences. With an eye toward a new era, we make recommendations for next steps and underscore the importance of transdisciplinary research.

Ancestry and dental development: A geographic and genetic perspective

OBJECTIVE

In this study, we investigated the influence of ancestry on dental development in the Generation R Study.

METHODS

Information on geographic ancestry was available in 3,600 children (1,810 boys and 1,790 girls, mean age 9.81 ± 0.35 years) and information about genetic ancestry was available in 2,786 children (1,387 boys and 1,399 girls, mean age 9.82 ± 0.34 years). Dental development was assessed in all children using the Demirjian method. The associations of geographic ancestry (Cape Verdean, Moroccan, Turkish, Dutch Antillean, Surinamese Creole and Surinamese Hindustani vs Dutch as the reference group) and genetic content of ancestry (European, African or Asian) with dental development was analyzed using linear regression models.

RESULTS

In a geographic perspective of ancestry, Moroccan (β = 0.18; 95% CI: 0.07, 0.28), Turkish (β = 0.22; 95% CI: 0.12, 0.32), Dutch Antillean (β = 0.27; 95% CI: 0.12, 0.41), and Surinamese Creole (β = 0.16; 95% CI: 0.03, 0.30) preceded Dutch children in dental development. Moreover, in a genetic perspective of ancestry, a higher proportion of European ancestry was associated with decelerated dental development (β = -0.32; 95% CI: -.44, -.20). In contrast, a higher proportion of African ancestry (β = 0.29; 95% CI: 0.16, 0.43) and a higher proportion of Asian ancestry (β = 0.28; 95% CI: 0.09, 0.48) were associated with accelerated dental development. When investigating only European children, these effect estimates increased to twice as large in absolute value.

CONCLUSION

Based on a geographic and genetic perspective, differences in dental development exist in a population of heterogeneous ancestry and should be considered when describing the physiological growth in children.

Natural variability of lung function in young healthy school children

Knowledge about long-term variability of lung function in healthy children is essential when monitoring and treating those with respiratory disease over time. The aim of this study was to define the natural variability in spirometry in young children after an interval of 12 months.The Size and Lung function In Children study was a prospective study designed to assess spirometry and body size, shape and composition in a multi-ethnic population of London school children. 14 schools with a wide range of socioeconomic circumstances were recruited. Spirometric and anthropometric assessments and parental questionnaires pertaining to respiratory symptoms, previous medical history, pubertal status and socioeconomic circumstances were completed at baseline and ∼1 year later.Technically acceptable spirometry data on two occasions ∼1 year apart (range 9-16 months) were available in 758 children (39% boys, mean±sd age 8.1±1.6 years), 593 of whom were classified as "healthy". Mean±sd within-subject between-test variability was 0.05±0.6 z-scores, with 95% of all the children achieving a between-test variability within ±1.2 z-scores (equating to ∼13% predicted).Natural variations of up to 1.2 z-scores occur in healthy children over ∼1 year. These must be considered when interpreting results from annual reviews in those with lung disease who are otherwise stable, if unnecessary further investigations or changes in treatment are to be avoided.

Lung function in children in relation to ethnicity, physique and socioeconomic factors

Can ethnic differences in spirometry be attributed to differences in physique and socioeconomic factors?Assessments were undertaken in 2171 London primary schoolchildren on two occasions 1 year apart, whenever possible, as part of the Size and Lung function In Children (SLIC) study. Measurements included spirometry, detailed anthropometry, three-dimensional photonic scanning for regional body shape, body composition, information on ethnic ancestry, birth and respiratory history, socioeconomic circumstances, and tobacco smoke exposure.Technically acceptable spirometry was obtained from 1901 children (mean (range) age 8.3 (5.2-11.8) years, 46% boys, 35% White, 29% Black-African origin, 24% South-Asian, 12% Other/mixed) on 2767 test occasions. After adjusting for sex, age and height, forced expiratory volume in 1 s was 1.32, 0.89 and 0.51 z-score units lower in Black-African origin, South-Asian and Other/mixed ethnicity children, respectively, when compared with White children, with similar decrements for forced vital capacity (p<0.001 for all). Although further adjustment for sitting height and chest width reduced differences attributable to ethnicity by up to 16%, significant differences persisted after adjusting for all potential determinants, including socioeconomic circumstances.Ethnic differences in spirometric lung function persist despite adjusting for a wide range of potential determinants, including body physique and socioeconomic circumstances, emphasising the need to use ethnic-specific equations when interpreting results.

John MA, Gaskin DA, Molaodi OR, Harding S. Associations of blood pressure with body composition among Afro-Caribbean children in Barbados

Despite complex presentation of adult hypertension and a concomitant obesity epidemic, little is known about overweight in relation to blood pressure among Caribbean children. We examined blood pressure in relation to body size in a cross-sectional study of 573 Barbadian children aged 9–10 years (2010-2011).The United States normative blood pressure percentiles were used to identify children with high (≥ 95^th percentile) or high normal blood pressure (90^th – 95^th percentile). The World Health Organization body mass index cut-off points were used to assess weight status.