Post-2000 growth trajectories in children aged 4-11 years: A review and quantitative analysis

Reference growth curves of anthropometric markers in Brazilian children and adolescents aged 7-14 years from southern Brazil

Reference growth curves are viable tools for monitoring somatic growth. Therefore, the objective of this study was to develop reference growth curves for body mass, height, body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR) in Brazilian children and adolescents aged 7-14 years. The reference growth curves were constructed from a cross-sectional panel study using data from four surveys conducted in 2002, 2007, 2012/2013 and 2018/2019, with 9675 children and adolescents aged 7-14 years, of both sexes from Florianopolis, Southern Brazil. Growth curves were constructed using the LMS method, based on anthropometric indicators and indices (body mass, height, BMI, WC and WHtR), measured according to standardised norms. There was an increase in body mass, height, BMI and WC values with increasing age in both sexes and percentiles (P5, P10, P25, P50, P75, P85 and P95). The girls presented higher values of body mass, BMI and WC in the analysed percentiles, compared to the boys. Regarding height, there was a higher value from 10 to 11 years old in girls and from 12 to 14 years old in boys. WHtR decreased with increasing age in both sexes and analysed percentiles. Region-specific reference growth curves can enable the monitoring of somatic growth of particular paediatric populations, expanding discussions in different regions of the world.

Ethnoracial disparities in childhood growth trajectories in Brazil: a longitudinal nationwide study of four million children

BACKGROUND

The literature contains scarce data on inequalities in growth trajectories among children born to mothers of diverse ethnoracial background in the first 5 years of life.

OBJECTIVE

We aimed to investigate child growth according to maternal ethnoracial group using a nationwide Brazilian database.

METHODS

A population-based retrospective cohort study employed linked data from the CIDACS Birth Cohort and the Brazilian Food and Nutrition Surveillance System (SISVAN). Children born at term, aged 5 years or younger who presented two or more measurements of length/height (cm) and weight (kg) were followed up between 2008 and 2017. Prevalence of stunting, underweight, wasting, and thinness were estimated. Nonlinear mixed effect models were used to estimate childhood growth trajectories, among different maternal ethnoracial groups (White, Asian descent, Black, Pardo, and Indigenous), using the raw measures of weight (kg) and height (cm) and the length/height-for-age (L/HAZ) and weight-for-age z-scores (WAZ). The analyses were also adjusted for mother's age, educational level, and marital status.

RESULTS

A total of 4,090,271 children were included in the study. Children of Indigenous mothers exhibited higher rates of stunting (26.74%) and underweight (5.90%). Wasting and thinness were more prevalent among children of Pardo, Asian, Black, and Indigenous mothers than those of White mothers. Regarding children's weight (kg) and length/height (cm), those of Indigenous, Pardo, Black, and Asian descent mothers were on average shorter and weighted less than White ones. Regarding WAZ and L/HAZ growth trajectories, a sharp decline in average z-scores was evidenced in the first weeks of life, followed by a period of recovery. Over time, z-scores for most of the subgroups analyzed trended below zero. Children of mother in greater social vulnerability showed less favorable growth.

CONCLUSION

We observed racial disparities in nutritional status and childhood growth trajectories, with children of Indigenous mothers presenting less favorable outcomes compared to their White counterparts. The strengthening of policies aimed at protecting Indigenous children should be urgently undertaken to address systematic ethnoracial health inequalities.

Latent Classes of Anthropometric Growth in Early Childhood Using Uni- and Multivariate approaches in a South African Birth Cohort

Background

Conventional methods for modelling longitudinal growth data focus on the analysis of mean longitudinal trends or the identification of abnormal growth based on cross-sectional standardized z-scores. Latent Class Mixed Modelling (LCMM) considers the underlying heterogeneity in growth profiles and allows for the identification of groups of subjects that follow similar longitudinal trends.

Methods

LCMM was used to identify underlying latent profiles of growth for univariate responses of standardized height, standardized weight, standardized body mass index and standardized weight-for-length/height measurements and multivariate response of joint standardized height and standardized weight measurements from birth to five years for a sample of 1143 children from a South African birth cohort, the Drakenstein Child Health Study (DCHS). Allocations across latent growth classes were compared to better understand the differences and similarities across the classes identified given different composite measures of height and weight as input.

Results

Four classes of growth within standardized height (n1=516, n2=112, n3=187, n4=321) and standardized weight (n1=263, n2=150, n3=584, n4=142), three latent growth classes within Body Mass Index (BMI) (n1=481, n2=485, n3=149) and Weight for length/height (WFH) (n1=321, n2=710, n3=84) and five latent growth classes within the multivariate response of standardized height and standardized weight (n1=318, n2=205, n3=75, n4=296, n5=242) were identified, each with distinct trajectories over childhood. A strong association was found between various growth classes and abnormal growth features such as rapid weight gain, stunting, underweight and overweight.

Conclusions

With the identification of these classes, a better understanding of distinct childhood growth trajectories and their predictors may be gained, informing interventions to promote optimal childhood growth.

A novel systematic pipeline for increased predictability and explainability of growth patterns in children using trajectory features

OBJECTIVE

Longitudinal patterns of growth in early childhood are associated with health conditions throughout life. Knowledge of such patterns and the ability to predict them can lead to better prevention and improved health promotion in adulthood. However, growth analyses are characterized by significant variability, and pattern detection is affected by the method applied. Moreover, pattern labelling is typically performed based on ad hoc methods, such as visualizations or clinical experience. Here, we propose a novel pipeline using features extracted from growth trajectories using mathematical, statistical and machine-learning approaches to predict growth patterns and label them in a systematic and unequivocal manner.

METHODS

We extracted mathematical and clinical features from 9577 children growth trajectories embedded with machine-learning predictions of the growth patterns. We experimented with two sets of features (CAnonical Time-series Characteristics and trajectory features specific to growth), developmental periods and six machine-learning classifiers. Clinical experts provided labels for the detected patterns and decision rules were created to associate the features with the labelled patterns. The predictive capacity of the extracted features was validated on two heterogenous populations (The Applied Research Group for Kids and the 2004 Pelotas Birth Cohort, based in Canada and Brazil, respectively).

RESULTS

Features predictive ability measured by accuracy and F1 score was ≥ 80% and ≥ 0.76 respectively in both cohorts. A small number of features (n = 74) was sufficient to distinguish between growth patterns in both cohorts. Slope, intercept of the trajectory, age at peak value, start value and change of the growth measure were among the top identified features.

CONCLUSION

Growth features can be reliably used as predictors of growth patterns and provide an unbiased understanding of growth patterns. They can be used as tool to reduce the effort to repeat analysis and variability concerning anthropometric measures, time points and analytical methods, in the context of the same or similar populations.

Early life growth trajectories in cystic fibrosis are associated with lung function at age six

BACKGROUND

Higher growth percentiles are associated with more favorable lung function in cystic fibrosis (CF), prompting the creation of CF Foundation (CFF) nutritional guidelines.

OBJECTIVES

To describe early childhood growth trajectories within CF, to determine if growth trajectories are associated with differences in lung function at age six, and to identify factors that differ between trajectory groups.

METHODS

Retrospective cohort study of children diagnosed with CF and born 2000-2011 using the US CFF Patient Registry. Annualized growth parameters prior to age six were included in group-based trajectory modeling to identify unique early life growth trajectories. FEV1 percent predicted (FEV1pp) at age six was compared between trajectory groups using linear regression. Factors associated with group membership were identified using multinomial logistic regression.

RESULTS

6,809 children met inclusion criteria. Six discrete growth trajectories were identified, including three groups that began with growth parameters >50th percentile, termed: "always high", "gradual decliner", "rapid decliner", and three which began with growth parameters <50th percentile, termed: "rapid riser", "gradual riser", "always low". FEV1pp at age six was highest for the Always High trajectory. The Always Low trajectory was nearly 10% lower than the Always High trajectory. Sex, ethnicity, newborn screening and pancreatic function were associated with trajectory class membership.

CONCLUSIONS

Distinct early life growth trajectories were identified within CF. Trajectories that met CFF nutritional guideline recommendations were associated with higher FEV1pp at age six. CF care teams should continue to partner with families to encourage interventions to support optimal growth to improve lung function in CF.

Developmental trajectories at a high risk for childhood overweight/obesity

BACKGROUND

The associations between developmental patterns (trajectories) in children and maternal factors have been widely investigated, but paternal effects on these trajectories are unclear. This study aimed to determine child and parental factors involved in developmental trajectories at high risk for causing adverse cardiovascular (CV) profiles in children.

METHODS

We analyzed longitudinal anthropometric data from birth to the present and CV profiles of 1,832 healthy volunteers (51% girls) aged 3-15 years who participated in a nationwide study between July 2012 and January 2014. Six trajectory latent class growth models were developed using body mass index z- scores. Predictors for being in developmental trajectories at high risk for causing adverse CV profiles were determined by multivariate regression analysis.

RESULTS

The mean±standard deviation number of anthropometric data points was 12±3 for both boys and girls. Among the six trajectories, the infantile onset and continual increase groups had significantly worse levels of many CV profiles than those in the remaining groups. Paternal overweight/obesity was an independent predictor for boys being in the infantile onset group and for girls being in the continual increase group. Additionally, maternal pre-pregnancy overweight/obesity in boys and maternal excessive gestational weight gain in girls were independent predictors for being in the infantile onset group. Having no sibling in boys and an older maternal age were independent predictors for being in the continual increase group.

CONCLUSIONS

Interventions to prevent childhood obesity should include strategies that focus on fathers and mothers as well as those that focus on children with certain types of familial background.

Body height, weight, and Body Mass Index - magnitude and pace of secular changes in children and adolescents from Kraków (Poland) between 1983 and 2020

OBJECTIVE

The aim of this study was to analyze the occurrence and pace of secular trends regarding body height, weight, and Body Mass Index (BMI) among children and adolescents from Kraków (Poland) examined in 1983, 2000, 2010, and 2020.

METHODS

The study group consisted of 17 407 individuals (8650 girls and 8757 boys) aged 3-18 included in four cross-sectional studies conducted in 1983, 2000, 2010, and 2020.Analyzed anthropometric characteristics included body height (measured according to Martin's technique, with an anthropometer) and body weight. BMI was calculated as follows: body weight (kg)/body height² (m).

RESULTS

Results of the current study suggest that there was a cessation of previously observed secular increase of the body height in the examined population in the recent decade. Additionally, secular changes regarding body height, body mass, and BMI occurred noticeably slower in the recent decade compared to the previous years.

CONCLUSIONS

In conclusion, the rapid increase of body height in the years 1983-2000 and later secular increase of the body mass and BMI in 2000-2010 were probably associated mainly with significant socio-economic progress of the country. On the other hand, deceleration of those trends in 2010-2020, especially in regards to body height, may be associated with reaching the maximum genetically attainable body height in the examined population.

Identifying longitudinal-growth patterns from infancy to childhood: a study comparing multiple clustering techniques

BACKGROUND

Most studies on children evaluate longitudinal growth as an important health indicator. Different methods have been used to detect growth patterns across childhood, but with no comparison between them to evaluate result consistency. We explored the variation in growth patterns as detected by different clustering and latent class modelling techniques. Moreover, we investigated how the characteristics/features (e.g. slope, tempo, velocity) of longitudinal growth influence pattern detection.

METHODS

We studied 1134 children from The Applied Research Group for Kids cohort with longitudinal-growth measurements [height, weight, body mass index (BMI)] available from birth until 12 years of age. Growth patterns were identified by latent class mixed models (LCMM) and time-series clustering (TSC) using various algorithms and distance measures. Time-invariant features were extracted from all growth measures. A random forest classifier was used to predict the identified growth patterns for each growth measure using the extracted features.

RESULTS

Overall, 72 TSC configurations were tested. For BMI, we identified three growth patterns by both TSC and LCMM. The clustering agreement was 58% between LCMM and TS clusters, whereas it varied between 30.8% and 93.3% within the TSC configurations. The extracted features (n = 67) predicted the identified patterns for each growth measure with accuracy of 82%-89%. Specific feature categories were identified as the most important predictors for patterns of all tested growth measures.

CONCLUSION

Growth-pattern detection is affected by the method employed. This can impact on comparisons across different populations or associations between growth patterns and health outcomes. Growth features can be reliably used as predictors of growth patterns.

Parents' Perceptions on Barriers and Facilitators of Physical Activity among Schoolchildren: A Qualitative Study

Given that physical activity (PA) plays an important role in early childhood, understanding the factors that affect the practice of PA at an early age could help develop effective strategies for overcoming barriers and increasing activity levels in this age group. A qualitative study was conducted based on grounded theory aimed at exploring the perceptions of mothers and fathers from Cuenca and Ciudad Real (Castilla La Mancha, Spain) regarding barriers and facilitators of physical activity of their children during the adiposity rebound period. Data were collected using focus groups involving 46 parents of children in the 3rd grade of pre-school and 1st grade of elementary school. During the analysis, the socio-ecological model and grounded theory were used. The barriers encountered were the preferences of children for sedentary activities (individual factors), academic tasks as a main priority of parents, the influence of older siblings and the unfavorable school environment (microsystem), the lack of family conciliation (mesosystem), and barriers related to the built environment or lack of facilities for physical activity (exosystem). Facilitators were the preferences for active games (individual factors), parental models including the co-participation of parents in activities, the influence of friends, living in large homes, the support provided by teachers and the school (microsystem), living in rural areas, having sufficient facilities, favorable weather conditions (exosystem), and the existence of free or subsidized activities (macro system). Programs aimed at promoting PA in early childhood should include strategies that address contextual factors and not only focus on individual factors related to the child.

BMI trajectories after primary school-based lifestyle intervention: Unravelling an uncertain future. A mixed methods study

This mixed methods study aimed to examine plausible body mass index (BMI) trajectories after exposure to a primary school-based lifestyle intervention to aid in estimating the long-term intervention benefits. BMI trajectories for children at control schools (mean 7.6 years of age) were modelled until 20 years of age through extrapolating trial evidence (N = 1647). A reference scenario assumed that the observed 2-year effects of the 'Healthy Primary Schools of the Future' (HPSF) and 'Physical Activity Schools' (PAS) were fully maintained over time. This was modelled by applying the observed 2-year BMI effects until 20 years of age. Expert opinions on likely trends in effect maintenance after the 2-year intervention period were elicited qualitatively and quantitatively, and were used for developing alternative scenarios. Expert elicitation revealed three scenarios: (a) a constant exposure-effect and an uncontrolled environment with effect decay scenario, (b) a household multiplier and an uncontrolled environment with effect decay scenario, and (c) a household multiplier and maintainer scenario. The relative effect of HPSF at 20 years of age was -0.21 kg/m2 under the reference scenario, and varied from -0.04 kg/m2 (a) to -0.06 kg/m2 (b), and -0.50 kg/m2 (c). For PAS, the relative effect was -0.17 kg/m2 under the reference scenario, and varied from -0.04 kg/m2 (a, b), to -0.21 kg/m2 (c). The mixed methods approach proved to be useful in modelling plausible BMI trajectories and specifying uncertainty on effect maintenance. Further observations until adulthood could reduce the uncertainty around future benefits. This trial was retrospectively registered at Clinicaltrials.gov (NCT02800616).

Parents' and Teachers' Perceptions of Physical Activity in Schools: A Meta-Ethnography

The aim of this meta-ethnographic study was to analyze parents' and teachers' perceptions of barriers and facilitators to physical activity in children. Facilitators were the benefits of physical activity, modeling, participation, children's preferences, and factors supporting active transport. Barriers were quantifying the physical activity, parents' lack of time, the cost of activities, bad weather, traffic, long distances, and the lack of facilities and safety. The level of physical activity does not depend exclusively on individual factors related to the child; rather, barriers and facilitators are influenced by the social and school context and the physical and built environment. It is important that school nurses understand these contextual factors, so that they can take these into consideration when designing their intervention programs.

Long-term trends in the body mass index and obesity risk in Estonia: an age-period-cohort approach

OBJECTIVES

To analyse the age, period and cohort effects on the mean body mass index (BMI) and obesity over the past two decades in Estonia.

METHODS

Study used data from nationally representative repeated cross-sectional surveys on 11,547 men and 16,298 women from 1996 to 2018. The independent effects of age, period and cohort on predicted mean BMI and probability of obesity (BMI ≥ 30 kg/m²) were modelled using hierarchical age-period-cohort analysis.

RESULTS

Curvilinear association between age and mean BMI was found for men, whereas the increase in mean BMI was almost linear for women. The predicted mean BMI for 40-year-old men had increased by 6% and probability of obesity by 1.8 times over 1996-2018; the period effects were slightly smaller for women. Men from the 1970s birth cohort had higher mean BMI compared to the average, whereas no significant cohort effects were found for obesity outcome.

CONCLUSIONS

Population-level BMI changes in Estonia during 1996-2018 were mostly driven by period rather than cohort-specific changes.