Children of low socioeconomic status show accelerated linear growth in early childhood; results from the Generation R Study

Maternal education and its influence on child growth and nutritional status during the first two years of life: a systematic review and meta-analysis

Background

The first 1000 days of life are critical for a child's health and development. Impaired growth during this period is linked to increased child morbidity, mortality, and long-term consequences. Undernutrition is the main cause, and addressing it within the first 1000 days of life is vital. Maternal education is consistently identified as a significant predictor of child undernutrition, but its specific impact remains to be determined. This study presents a systematic review and meta-analysis investigating the influence of high versus low maternal education levels on child growth from birth to age two, using population-based cohort studies.

Methods

Databases including PubMed, Scopus, EMBASE, Web of Science, ERIC, and Google Scholar were searched from January 1990 to January 2024 using appropriate search terms. We included population-based cohort studies of healthy children aged two years and under and their mothers, categorizing maternal education levels. Child growth and nutritional outcomes were assessed using various indicators. Two reviewers independently conducted data extraction and assessed study quality. The Newcastle Ottawa scale was utilized for quality assessment. Random-effects models were used for meta-analysis, and heterogeneity was assessed using the Cochrane Q and I2 statistic. Subgroup and sensitivity analyses were performed, and publication bias was evaluated.

Findings

The literature search retrieved 14,295 titles, and after full-text screening of 639 reports, 35 studies were included, covering eight outcomes: weight for age z-score (WAZ), height for age z-score (HAZ), BMI for age z-scores (BMIZ), overweight, underweight, stunting, wasting, and rapid weight gain. In middle-income countries, higher maternal education is significantly associated with elevated WAZ (MD 0.398, 95% CI 0.301-0.496) and HAZ (MD 0.388, 95% CI 0.102-0.673) in children. Similarly, in studies with low-educated population, higher maternal education is significantly linked to increased WAZ (MD 0.186, 95% CI 0.078-0.294) and HAZ (0.200, 95% CI 0.036-0.365). However, in high-income and highly educated population, this association is either absent or reversed. In high-income countries, higher maternal education is associated with a non-significant lower BMI-Z (MD -0.028, 95% CI -0.061 to 0.006). Notably, this inverse association is statistically significant in low-educated populations (MD -0.045, 95% CI -0.079 to -0.011) but not in highly educated populations (MD 0.003, 95% CI -0.093 to 0.098).

Interpretation

Maternal education's association with child growth varies based on country income and education levels. Further research is needed to understand this relationship better.

Funding

This study was a student thesis supported financially by Tehran University of Medical Sciences (TUMS).

Latent growth analysis of children's height growth trajectories

Characterizing and quantifying the trajectories of variables of interest through time in their field of study is of interest to a range of disciplines. The aim of this study was to investigate the growth speed in height of children and its determinants. A total of 3401 males and 3200 females from four low- and middle-income countries with measured height on five occasions from 2002 to 2016 were included in the study. Data were analyzed using a latent growth model. The results of the study reported that children in four low- and middle-income countries exhibited substantial growth inequalities. There was a significant gender difference in change of growth with males had a higher baseline, rate of change, and acceleration in height growth than females. Comparing the component of slopes across countries, the growth change inequalities were observed among children. These inequalities were statistically significant, with the highest rate of change observed in Peru and Vietnam.

Describing the longitudinal breakfast quality index trajectories in early childhood: results from Melbourne InFANT program

BACKGROUND

Breakfast quality in early childhood remains understudied. This study describes the changes in breakfast quality index (BQI) (i.e. trajectory) in early childhood and assesses its associations with obesity outcomes.

METHODS

Data from children who participated in the Melbourne InFANT Program were used (n = 328). The Melbourne InFANT Program was a 15-month early obesity prevention intervention conducted from 2008 to 2013. Dietary intakes at ages 1.5, 3.5 and 5.0 years were assessed using three parent-proxy reported 24 h recalls. A revised nine-item BQI tool developed based on Australian dietary recommendations for young children was used to calculate BQI scores. Group-based trajectory modelling identified BQI trajectory groups. Multivariable linear and logistic regression examined the associations between identified BQI trajectory groups and obesity outcomes at age 5 years.

RESULTS

Mean BQI at ages 1.5, 3.5 and 5.0 years was 4.8, 4.8, 2.7 points, respectively. Two BQI trajectory groups were identified, and both showed a decline in BQI. The mean BQI of most children (74%) decreased from 5.0 to 4.0 points from ages 1.5 to 5.0 years (referred as "High BQI" group). The remaining children (26%) had a mean BQI of 4.8 and 1.2 points at age 1.5 and 5.0 years, respectively (referred as "Low BQI" group). The "Low BQI" group appeared to show higher risk of overweight (OR:1.30, 95% CI: 0.60, 2.81, P = 0.66) at age 5 years than the "High BQI" group. No difference in body mass index (BMI) z-score was found between the two groups.

CONCLUSIONS

Two BQI trajectory groups were identified. Both groups showed a decline in breakfast quality from ages 1.5 to 5.0 years. Our study highlights the need for early health promotion interventions and strategies to improve and maintain breakfast quality across early childhood.

Analysis of risk factors and construction of a prediction model for short stature in children

BACKGROUND

Short stature in children is an important global health issue. This study aimed to analyze the risk factors associated with short stature and to construct a clinical prediction model and risk classification system for short stature.

METHODS

This cross-sectional study included 12,504 children aged 6-14 years of age from 13 primary and secondary schools in Pingshan District, Shenzhen. A physical examination was performed to measure the height and weight of the children. Questionnaires were used to obtain information about children and their parents, including sex, age, family environment, social environment, maternal conditions during pregnancy, birth and feeding, and lifestyle. The age confounding variable was adjusted through a 1 : 1 propensity score matching (PSM) analysis and 1,076 children were selected for risk factor analysis.

RESULTS

The prevalence of short stature in children aged 6-14 years was 4.3% in the Pingshan District, Shenzhen. The multivariate logistic regression model showed that the influencing factors for short stature were father's height, mother's height, annual family income, father's level of education and parents' concern for their children's height in the future (P < 0.05). Based on the short stature multivariate logistic regression model, a short stature nomogram prediction model was constructed. The area under the ROC curve (AUC) was 0.748, indicating a good degree of discrimination of the nomogram. According to the calibration curve, the Hosmer-Lemesio test value was 0.917, and the model was considered to be accurate. Based on a risk classification system derived from the nomogram prediction model, the total score of the nomogram was 127.5, which is considered the cutoff point to divides all children into low-risk and high-risk groups.

CONCLUSION

This study analyzed the risk factors for short stature in children and constructed a nomogram prediction model and a risk classification system based on these risk factors, as well as providing short stature screening and assessment individually.

Interpreting error in the estimation of skeletal growth profiles from past populations: An example demonstrating skeletal growth in historic African American communities

OBJECTIVES

The study of growth in the past is a critical component of bioarcheological analyses. However, our understanding of growth in the past is subject to a number of methodological challenges. This study aims to model the skeletal growth of past populations by considering the challenges associated with the data collection process and the challenges associated with the age estimation procedures.

MATERIALS AND METHODS

We use skeletal remains from two historic African American cemeteries in the American South to model femoral diaphyseal length-for-age. We estimate the age of each individual using dental development techniques and present growth curves as both a product of the maximum likelihood (MLE) age estimate and the estimated posterior age distribution. Growth was compared against a reference sample from the University of Colorado Child Research Council Study.

RESULTS

The results of our analyses showed that femoral diaphyseal length in two historic African American communities is small-for-estimated age as compared to a modern reference sample. However, the magnitude and characterization of this difference is variable when taking into account the broader posterior age distribution.

DISCUSSION

Both samples may be small-for-age due to physiological stress associated with racism, inequality, and the compounding effects of early urbanization. However, the interpretation of growth in the past is muddled when considering the relationship between the study sample and the reference sample, when accounting for uncertainty in the age estimation procedure, and the error-inducing steps taken during the data collection process. Future interpretation of skeletal growth in the past must include a full account of the possible sources of error in order to present an accurate representation of growth.

Nonlinear Physical Growth of Children from Infancy to Middle Adolescence in Low- and Middle-Income Countries

BACKGROUND

The growth curve has a significant role in understanding the growth trajectories over time and examining the mathematical relationship between the outcome variable and time.

STUDY DESIGN

A longitudinal prospective cohort study.

METHODS

This study aimed to identify a nonlinear growth curve that best represents the growth trajectories in children's physical growth from ages 1 to 15 years. The data were obtained from the Young Lives study conducted in Ethiopia, India, Peru, and Vietnam. Nonlinear growth curves were studied through the families of three-parameter nonlinear mixed-effects models.

RESULTS

The study examined the performances of different three-parameter nonlinear growth curves for the growth trajectory analysis, and the Logistic curve was chosen for the trajectory analysis. Gender and country differences had significant effects on the child's growth. Females reached asymptotic height earlier and shorter than males. The mean height values at the end of the growth stage for children in Ethiopia, India, Peru, and Vietnam were 171.78, 170.37, 171.30, 174.31cm, respectively. Children in Ethiopia approached adult height earlier than those in India but later than children in Peru. However, no significant growth change was observed between children in Ethiopia and Vietnam. This indicates that children in Ethiopia and Vietnam have no significant differences regarding approaching adult height.

CONCLUSION

The study concludes that the Logistic curve was found to be the best growth curve to describe the growth trajectories. Children in all four countries exhibited different growth parameters.

Stature estimation for Saudi men based on different combinations of upper limb part dimensions

Estimating stature based on body/limb parts can help define the characteristics of unidentified bodies. The most studied upper limb part is the hand, although few studies have examined whether stature can be estimated using fingers plus other hand dimensions. Moreover, there is paucity in anthropometric studies that determined whether bilateral whole limb parts (e.g., arms, forearms, and hands) are related to stature among the living subjects.This prospective cross-sectional study aimed to evaluate the relationship between different upper limb measurements and the stature of Saudi men. Furthermore, I assessed whether upper limb asymmetry was present, and developed regression models to estimate stature based on different available measurements. Stature and 13 upper limb parameters were measured for 100 right-handed Saudi men who were 18 to 24 years old.All measurements were positively correlated with stature (P < .001), and the best single predictor was the bilateral ulnar length. Asymmetry was more pronounced in the hand measurements. A multiparameter model provided reasonable predictive accuracy (±3.77-5.68 cm) and was more accurate than single-parameter models. Inclusion of the right-side fingers improved the model's accuracy.This study developed potential models for estimating stature during the identification of bodies of Saudi men.

Identifying distinct trajectories of acute otitis media in children: A prospective cohort study

Objectives

To identify possibly distinct acute otitis media (AOM) trajectories in childhood and identify determinants associated with specific AOM trajectories. To explore which child will become prone to recurrent AOM episodes and which will not.

Design

Population‐based prospective cohort study among 7863 children from birth until 10 years and their mothers.

Methods

This study was embedded in the Generation R Study: a population‐based prospective cohort study. Data on AOM and determinants were collected by repeated parental questionnaires. Distinct AOM trajectories within the population were identified with latent‐class analyses. Next, using multivariate analysis we checked whether specific determinants were associated with specific trajectories.

Results

Three distinct trajectories were identified; that is, non–otitis prone, early AOM—that is children who suffered AOM episodes until 3 years of age but not beyond, and persistent AOM—that is children who remained otitis‐prone. Male gender (OR: 1.26, CI: 1.11‐1.43) and day‐care attendance (OR: 1.31, CI: 1.06‐1.60) were associated with increased odds of early AOM. Breastfeeding was beneficial for children in both the early‐AOM and persistent‐AOM trajectories (OR: 0.78 and 0.77, respectively). Birth in the summer or autumn as compared with birth in the spring decreased odds of AOM only in the persistent‐AOM trajectory. Half of all AOM‐prone children recovered after the age of 3 years.

Conclusion

Specific determinants are associated with different AOM trajectories. Future research is needed to better predict which child will remain otitis‐prone and which recovers after the age of 3 years to better tailor treatment towards the needs of the individual child.

Sociodemographic predictors of early postnatal growth: evidence from a Chilean infancy cohort

OBJECTIVES

Infant anthropometric growth varies across socioeconomic factors, including maternal education and income, and may serve as an indicator of environmental influences in early life with long-term health consequences. Previous research has identified sociodemographic gradients in growth with a focus on the first year and beyond, but estimates are sparse for growth before 6 months. Thus, our objective was to examine the relationship between sociodemographic factors and infant growth patterns between birth and 5 months of age.

DESIGN

Prospective cohort study.

SETTINGS

Low-income to middle-income neighbourhoods in Santiago, Chile (1991-1996).

PARTICIPANTS

1412 participants from a randomised iron-deficiency anaemia preventive trial in healthy infants.

MAIN OUTCOME MEASURES

Longitudinal anthropometrics including monthly weight (kg), length (cm) and weight-for-length (WFL) values. For each measure, we estimated three individual-level growth parameters (size, timing and velocity) from SuperImposition by Translation and Rotation models. Size and timing changes represent vertical and horizontal growth curve shifts, respectively, and velocity change represents growth rate shifts. We estimated the linear association between growth parameters and gestational age, maternal age, education and socioeconomic position (SEP).

RESULTS

Lower SEP was associated with a slower linear (length) velocity growth parameter (-0.22, 95% CI -0.31 to -0.13)-outcome units are per cent change in velocity from the average growth curve. Lower SEP was associated with later WFL growth timing as demonstrated through the tempo growth parameter for females (0.25, 95% CI 0.05 to 0.42)-outcome units are shifts in days from the average growth curve. We found no evidence of associations between SEP and the weight size, timing or velocity growth rate parameters.

CONCLUSION

Previous research on growth in older infants and children shows associations between lower SEP with slower length velocity. We found evidence supporting this association in the first 5 months of life, which may inform age-specific prevention efforts aimed at infant length growth.

Environmental determinants associated with acute otitis media in children: a longitudinal study

BACKGROUND

Acute otitis media (AOM) is a common pediatric disease and frequent reason for antibiotic treatment. We aimed to identify environmental and host factors associated with AOM and assess which determinants were associated with AOM at specific ages.

METHODS

This study among 7863 children was embedded in the Generation R Study: a population-based prospective cohort study from fetal life onwards. Data on outcome and possible determinants were collected using questionnaires until 6 years. We used generalized estimating equation models to examine associations with AOM with longitudinal odds at different ages, considering correlations between repeated measurements.

RESULTS

Male gender increased odds of AOM in children at 2, 3, and 4 years but not at other ages. Postnatal household smoking, presence of siblings, and pet birds increased odds of AOM. Breastfeeding decreased AOM odds, most notably in the first 2 months of life. No association was found for season of birth, maternal age, ethnicity, aberrant birth weight for gestational age, prenatal smoking, furry pets, and daycare attendance.

CONCLUSIONS

Risk of childhood AOM varies with age. Significant association with AOM was found for gender and breastfeeding at specific ages and for household smoking, presence of siblings, and pet birds at all the studied ages.

Growth velocity curves and pubertal spurt parameters of Peruvian children and adolescents living at different altitudes. The Peruvian health and optimist growth study

OBJETIVE

To estimate the growth parameters of Peruvian children and adolescents living at different altitudes.

METHODS

The sample comprised 10 795 Peruvian children and adolescents (5781 girls, aged 6-7 years) from sea level, the Amazon region, and high altitude. Height was measured with standardized techniques. Mathematical and biological growth parameters were estimated using the Preece-Baines growth model I.

RESULTS

Sea-level children and adolescents experienced peak height velocity (PHV) at an earlier age (girls, 8.56 ± 2.37 years; boys, 12.03 ± 0.58 years) were taller at the time of PHV (girls, 144.1 ± 1.9 cm; boys, 154.3 ± 1.4 cm), had higher PHV (girls, 6.23 ± 3.87 cm/year; boys, 7.52 ± 2.31 cm/year), and had a taller estimated final height (girls, 154.2 ± 0.3 cm; boys, 166.3 ± 1.0 cm) compared to those living at high altitude (girls, 152.7 ± 0.7 cm; boys, 162.8 ± 0.8 cm) or in the Amazon region (152.1 ± 0.4 cm; boys, 162.2 ± 0.6 cm). Across all geographical areas, PHV occurred approximately 2 years earlier in girls (9.68 ± 0.99 years) than in boys (12.61 ± 0.42 years), their estimated PHV was 5.88 ± 1.92 cm/year vs 6.45 ± 1.09 cm/year, their size at PHV was 142.2 ± 1.4 cm vs 152.8 ± 0.7 cm, and their final adult height was estimated to be 153.1 ± 0.3 cm vs 164.2 ± 0.7 cm.

CONCLUSIONS

Peruvian children and adolescents' physical growth timing and tempo were influenced by their living altitudes. Those living at sea level experienced an earlier age at PHV were taller at time of PHV, had a higher PHV, and had a taller estimated final height compared to those living at higher altitudes. Girls and boys also differed significantly in their growth parameters.

Environmental and birth characteristics as predictors of short stature in early childhood

AIM

To evaluate for environmental and birth characteristic predictors of short stature in a large nationally representative sample.

METHODS

We evaluated 10 127 children from the Early Childhood Longitudinal Study-Kindergarten 2011 cohort, using univariate and multivariable linear and logistic regression to evaluate factors associated with short stature (height <3rd percentile) at kindergarten through second grade. Predictors included birthweight, preterm status, sex, parental education, parental income and race/ethnicity.

RESULTS

Lower birthweight was associated with short stature, with each decreasing kilogram having a 2.45 adjusted odds ratio (aOR; 95% confidence interval [CI] 1.81, 3.33) of short stature for term children in second grade. Preterm children (compared to term children) had an aOR of 2.23 (CI 1.32, 3.78) for short stature. Other predictors of short stature included female sex and lower parental income. African American children had a lower risk of short stature (aOR 0.34, CI 0.14, 0.82) compared to white children.

CONCLUSION

Predictors of short stature include lower birthweight, preterm status, female sex and parental income. Socio-economic disparities and race/ethnicity further influenced height. These data may assist paediatricians in considering contributors to stature outcomes by early school age.

Poverty and a child's height development during early childhood: A double disadvantage? A study of the 2006-2009 birth cohorts in Flanders

Introduction

Poverty is a well-known risk factor for a child’s health and development. This paper aimed to establish whether poverty negatively affected both intra-uterine growth and early childhood growth, i.e., whether children facing poverty were at a double disadvantage.

Methods

For this study, we made use of routinely collected data on child development throughout early childhood from the 2006–2009 birth cohorts in Kind & Gezin’s Ikaros database collected during 2,605,975 consultations with 273,935 children from birth to 730 days old. Indicators for child development at birth were gestational age and height-at-birth. A standardized height-for-age indicator captured height development throughout early childhood. A multidimensional indicator measured the risk of poverty. For the analysis of development at birth, we used linear and logistic regression; for the analysis of height development during early childhood, we estimated linear and logistic growth curve models.

Results

The risk of poverty negatively affected both gestational age and height-at-birth. Throughout early childhood, we observed a negative relation between the risk of poverty and height-for-age indicators. However, the effect varied throughout childhood. Children at risk of poverty (over)compensated for their smaller stature at birth, and between ages 6 and 18 months, approximately, the negative effects of risk of poverty decreased substantially or disappeared. However, towards the end of the period studied, children born in households at risk of poverty started to lag again in height development.

Conclusion

This study found that the risk of poverty indeed negatively affected a child’s growth, both in utero and in early childhood. However, the results suggest that developmental lags later in childhood were not merely an extension of such lags at birth.

Nutrition and growth: assessing the impact of regional nutritional intake on childhood development and metacarpal parameters

Measuring skeletal development throughout juvenile growth can provide a greater understanding into the health, hormonal function and genetics of children. The metacarpals have been of interest for their potential to provide insights into healthy juvenile skeletal development. This study investigated the growth patterns of developing females from isolated communities who had varied diets. Anthropometrical measurements and hand-wrist X-rays were taken of 353 juvenile females from three populations: Pari Coastal Village and Bundi Highlands Village, Papua New Guinea (PNG); and Brisbane, Australia between 1968 to 1983. Radiographs were digitized, and the length and width of the second and third metacarpals compared to each subject's height and weight. As subject heights increased, metacarpal length and width increased. However, stature and second metacarpal length indicated the strongest correlation (P<0.01), compared to third metacarpal length (P<0.01) or width. From 11 to 13 years of age, Brisbane subjects were significantly heavier and taller in comparison to subjects from PNG, and coastal females were heavier and taller than the highland females. A prominent difference between the two PNG populations was the regional intake of protein in their diets. The second metacarpal presents particularly accurate measurements when determining the height or development of a child. Nutritional intake appears to have a major influence normal childhood growth, with a potential for protein deficiency to strongly inhibit growth. Any delayed growth is particularly evident in the child's stature, as well as in the development of the metacarpal long bones of the hand.

Socioeconomic differences in children’s growth trajectories from infancy to early adulthood: evidence from four European countries

Background

Height is regarded as a marker of early-life illness, adversity, nutrition and psychosocial stress, but the extent to which differences in height are determined by early-life socioeconomic circumstances, particularly in contemporary populations, is unclear. This study examined socioeconomic differences in children’s height trajectories from birth through to 21 years of age in four European countries.

Methods

Data were from six prospective cohort studies—Generation XXI, Growing Up in Ireland (infant and child cohorts), Millennium Cohort Study, EPITeen and Cardiovascular Risk in Young Finns Study—comprising a total of 49 492 children with growth measured repeatedly from 1980 to 2014. We modelled differences in children’s growth trajectories over time by maternal educational level using hierarchical models with fixed and random components for each cohort study.

Results

Across most cohorts at practically all ages, children from lower educated mothers were shorter on average. The gradient in height was consistently observed at 3 years of age with the difference in expected height between maternal education groups ranging between −0.55 and −1.53 cm for boys and −0.42 to −1.50 cm for girls across the different studies and widening across childhood. The height deficit persists into adolescence and early adulthood. By age 21, boys from primary educated maternal backgrounds lag the tertiary educated by −0.67 cm (Portugal) and −2.15 cm (Finland). The comparable figures for girls were −2.49 cm (Portugal) and −2.93 cm (Finland).

Conclusions

Significant differences in children’s height by maternal education persist in modern child populations in Europe.

Effects of socioeconomic position and social mobility on linear growth from early childhood until adolescence

OBJECTIVE

To assess the effect of socioeconomic position (SEP) in childhood and social mobility on linear growth through adolescence in a population-based cohort.

METHODS

Children born in Cuiabá-MT, central-western Brazil, were evaluated during 1994 - 1999. They were first assessed during 1999 - 2000 (0 - 5 years) and again during 2009 - 2011 (10 - 17 years), and their height-for-age was evaluated during these two periods.Awealth index was used to classify the SEP of each child's family as low, medium, or high. Social mobility was categorized as upward mobility or no upward mobility. Linear mixed models were used.

RESULTS

We evaluated 1,716 children (71.4% of baseline) after 10 years, and 60.6% of the families showed upward mobility, with a higher percentage among the lowest economic classes. A higher height-for-age was also observed among those from families with a high SEP both in childhood (low SEP= -0.35 z-score; high SEP= 0.15 z-score, p < 0.01) and adolescence (low SEP= -0.01 z-score; high SEP= 0.45 z-score, p < 0.01), whereas upward mobility did not affect their linear growth.

CONCLUSION

Expressive social mobility was observed, but SEP in childhood and social mobility did not greatly influence linear growth through childhood in this central-western Brazilian cohort.

Mothering and anxiety: Social support and competence as mitigating factors for first-time mothers

This study investigated anxiety as a phenomenon distinct from depression and evaluated several variables that influence anxiety in first-time mothers. This explored the relationship between maternal sense of competence (both of mothering and efficacy) and perceived social support (from family, friends, and significant others) and first-time mothers' postpartum anxiety, when depression, socioeconomic status (SES), and marital status were controlled for. The population studied were 86 first-time mothers made up of women with children 24 months or younger in two populations of Kentucky and Michigan. The constructs of maternal sense of competence and perceived social support were found to be significant in explaining first-time mothers' anxiety. The study concluded that a combined association of perceived social support and maternal sense of competence were associated with a 34% (change in R-squared = .339) decrease of a first-time mothers' anxiety. However, not all types of social support, or maternal competence appeared to be equally important with regards to maternal anxiety: social support from friends and family and maternal sense of competence in regard to productivity appeared to be most significant. Lastly, some recommendations for health practitioners who work with mothers are provided.

Connecting the Dots in Childhood Obesity Disparities: A Review of Growth Patterns from Birth to Pre-Adolescence

In this review, we considered how disparities in obesity emerge between birth, when socially disadvantaged infants tend to be small, and later in childhood, when socially disadvantaged groups have high risk of obesity. We reviewed epidemiologic evidence of socioeconomic and racial/ethnic differences in growth from infancy to pre-adolescence. Minority race/ethnicity and lower socioeconomic status was associated with rapid weight gain in infancy but not in older age groups, and social differences in linear growth and relative weight were unclear. Infant feeding practices was the most consistent mediator of social disparities in growth, but mediation analysis was uncommon and other factors have only begun to be explored. Complex life course processes challenge the field of social epidemiology to develop innovative study designs and analytic techniques with which to pose and test challenging yet impactful research questions about how obesity disparities evolve throughout childhood.

Associations of maternal folic acid supplementation and folate concentrations during pregnancy with foetal and child head growth: the Generation R Study

PURPOSE

Folic acid supplementation during pregnancy has been associated with a reduced risk of common neurodevelopmental delays in the offspring. However, it is unclear whether low folate status has effects on the developing brain. We evaluated the associations of maternal folic acid supplementation and folate concentrations during pregnancy with repeatedly measured prenatal and postnatal head circumference in the offspring.

METHODS

Within a population-based prospective cohort, we measured maternal plasma folate concentrations at approximately 13 weeks of gestation (90 % range 10.5-17.2) and assessed folic acid supplementation by questionnaire (2001-2005). Up to 11 repeated measures of head circumference were obtained during foetal life (20 and 30 weeks of gestation) and childhood (between birth and age 6 years) in 5866 children (2002-2012).

RESULTS

In unadjusted models, foetal head growth was 0.006 SD (95 % CI 0.003; 0.009, P < 0.001) faster per week per 1-SD higher maternal folate concentration. After adjustment for confounders, this association was attenuated to 0.004 SD per week (95 % CI 0.000; 0.007, P = 0.02; estimated absolute difference at birth of 2.7 mm). The association was independent of overall foetal growth. No associations were found between maternal folate concentrations and child postnatal head growth. Preconceptional start of folic acid supplementation was associated with larger prenatal head size, but not with prenatal or postnatal head growth.

CONCLUSIONS

Our results suggest an independent, modest association between maternal folate concentrations in early pregnancy and foetal head growth. More research is needed to identify whether specific brain regions are affected and whether effects of folate on foetal head growth influence children's long-term functioning.

A Review of the Relationship Between Socioeconomic Position and the Early-Life Predictors of Obesity

A range of important early-life predictors of later obesity have been identified. Children of lower socioeconomic position (SEP) have a steeper weight gain trajectory from birth with a strong socioeconomic gradient in child and adult obesity prevalence. An assessment of the association between SEP and the early-life predictors of obesity has been lacking. The review involved a two-stage process: Part 1, using previously published systematic reviews, we developed a list of the potentially modifiable determinants of obesity observable in the pre-natal, peri-natal or post-natal (pre-school) periods; and part 2, conducting a literature review of evidence for socioeconomic patterning in the determinants identified in part 1. Strong evidence was found for an inverse relationship between SEP and (1) pre-natal risk factors (pre-pregnancy maternal body mass index (BMI), diabetes and pre-pregnancy diet), (2) antenatal/peri natal risk factors (smoking during pregnancy and low birth weight) and (3) early-life nutrition (including breastfeeding initiation and duration, early introduction of solids, maternal and infant diet quality, and some aspects of the home food environment), and television viewing in young children. Less strong evidence (because of a lack of studies for some factors) was found for paternal BMI, maternal weight gain during pregnancy, child sleep duration, high birth weight and lack of physical activity in young children. A strong socioeconomic gradient exists for the majority of the early-life predictors of obesity suggesting that the die is cast very early in life (even pre-conception). Lifestyle interventions targeting disadvantaged women at or before child-bearing age may therefore be particularly important in reducing inequality. Given the likely challenges of reaching this target population, it may be that during pregnancy and their child's early years are more feasible windows for engagement.

Effects of parental socio-economic conditions on facial attractiveness

Socio-economic conditions during early life are known to affect later life outcomes such as health or social success. We investigated whether family socio-economic background may also affect facial attractiveness. We used the Wisconsin Longitudinal Study (n = 8434) to analyze the association between an individual's parental socio-economic background (in terms of father's highest education and parental income) and that individual's facial attractiveness (estimated by rating of high school yearbook photographs when subjects were between 17 and 20 years old), controlling for subjects' sex, year of birth, and father's age at subjects' birth. Subjects' facial attractiveness increased with increasing father's highest educational attainment as well as increasing parental income, with the latter effect being stronger for female subjects as well. We conclude that early socio-economic conditions predict, to some extent, facial attractiveness in young adulthood.

Effects of Parental Socio-Economic Conditions on Facial Attractiveness

Socio-economic conditions during early life are known to affect later life outcomes such as health or social success. We investigated whether family socio-economic background may also affect facial attractiveness. We used the Wisconsin Longitudinal Study ( n = 8434) to analyze the association between an individual's parental socioeconomic background (in terms of father's highest education and parental income) and that individual's facial attractiveness (estimated by rating of high school yearbook photographs when subjects were between 17 and 20 years old), controlling for subjects' sex, year of birth, and father's age at subjects' birth. Subjects' facial attractiveness increased with increasing father's highest educational attainment as well as increasing parental income, with the latter effect being stronger for female subjects as well. We conclude that early socio-economic conditions predict, to some extent, facial attractiveness in young adulthood.

Socioeconomic differences in childhood length/height trajectories in a middle-income country: a cohort study

BACKGROUND

Socioeconomic disadvantage is associated with shorter adult stature. Few studies have examined socioeconomic differences in stature from birth to childhood and the mechanisms involved, particularly in middle-income former Soviet settings.

METHODS

The sample included 12,463 Belarusian children (73% of the original cohort) born in 1996-1997, with up to 14 stature measurements from birth to 7 years. Linear spline multi-level models with 3 knots at 3, 12 and 34 months were used to analyse birth length and growth velocity during four age-periods by parental educational achievement (up to secondary school, advanced secondary/partial university, completed university) and occupation (manual, non-manual).

RESULTS

Girls born to the most (versus least) educated mothers were 0.43 cm (95% confidence interval (CI): 0.28, 0.58) longer at birth; for boys, the corresponding difference was 0.30 cm (95% CI: 0.15, 0.46). Similarly, children of the most educated mothers grew faster from birth-3 months and 12-34 months (p-values for trend ≤ 0.08), such that, by age 7 years, girls with the most (versus least) educated mothers were 1.92 cm (95% CI: 1.47, 2.36) taller; after controlling for urban/rural and East/West area of residence, this difference remained at 1.86 cm (95% CI: 1.42, 2.31), but after additionally controlling for mid-parental height, attenuated to 1.10 cm (95% CI: 0.69, 1.52). Among boys, these differences were 1.95 cm (95% CI: 1.53, 2.37), 1.89 cm (95% CI: 1.47, 2.31) and 1.16 cm (95% CI: 0.77, 1.55), respectively. Additionally controlling for breastfeeding, maternal smoking and older siblings did not substantively alter these findings. There was no evidence that the association of maternal educational attainment with growth differed in girls compared to boys (p for interaction = 0.45). Results were similar for those born to the most (versus least) educated fathers, or who had a parent with a non-manual (versus manual) occupation.

CONCLUSIONS

In Belarus, a middle-income former Soviet country, socioeconomic differences in offspring growth commence in the pre-natal period and generate up to approximately 2 cm difference in height at age 7 years. These associations are partly explained by genetic or other factors influencing parental stature.

TRIAL REGISTRATION

Current Controlled Trials: NCT01352247 assigned 9 Sept 2005; ClinicalTrials.gov. Identifier: NCT01561612 received 20 Mar 2012.

Maternal life course socio-economic position and offspring body composition at birth in a multi-ethnic population

BACKGROUND

Size and body composition at birth may affect long-term health. Mean birthweight and body composition differ between ethnic groups living in Europe. We wanted to explore if this relates to differences in socio-economic conditions in country of origin and over the maternal life course.

METHODS

This is a population-based cohort study of healthy pregnant women living in Oslo, Norway. Data on maternal early life and present socio-economic position (SEP) were collected in early gestation, and SEP scores were extracted through two separate principal components analyses. The associations between maternal present SEP and four different offspring anthropometric measures at birth were assessed separately, stratified by maternal early life SEP (dichotomised score) and Human Development Index (HDI, a country-level socio-economic indicator) in the country of origin [high HDI (Reference), n = 287 and low HDI, n = 250].

RESULTS

A strong positive association between maternal present SEP and offspring birthweight was observed if maternal early life SEP was high, but not if maternal early life SEP was low (P < 0.001 for the interaction term). This interactional effect was observed in both HDI groups. Maternal life course SEP affected offspring birthweight mainly through an effect on length and sum of skin folds. Offspring of mothers with origin from low HDI countries had smaller abdominal circumference, possibly indicating less fat-free mass, regardless of maternal life course SEP.

CONCLUSION

Our results suggest that there are transgenerational effects of maternal past socio-economic conditions on offspring size and body composition at birth that modify the associations with present socio-economic factors.

Medication adherence and growth in children with CKD

BACKGROUND AND OBJECTIVES

Poor growth is a consequence of CKD, but can often be partially or fully prevented or corrected with the use of a number of medications. The extent of nonadherence with medications used to treat or mitigate growth failure in CKD has not been examined prospectively in children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The prevalence of both prescription of and nonadherence to recombinant human growth hormone (rhGH), phosphate binders, alkali, active vitamin D, nutritional vitamin D, iron, and erythrocyte-stimulating agents was summarized over the first seven visits of the Chronic Kidney Disease in Children cohort study. The association between self-reported nonadherence to each medication group and the mean annual change in age- and sex-specific height z score was quantified using seven separate linear regression models with generalized estimating equations.

RESULTS

Of 834 participants, 597 reported use of at least one of these medication groups and had adherence data available. Nonadherence ranged from 4% over all visits for erythrocyte-stimulating agents to 22% over all visits for nutritional vitamin D. Of the study participants, 451 contributed data to at least one of the analyses of adherence and changes in height z score. Children nonadherent to rhGH had no change in height z score, whereas those adherent to rhGH had a significant improvement of 0.16 SDs (95% confidence interval, 0.05 to 0.27); the effect size was slightly larger and remained significant after adjustment. Among participants with height≤3rd percentile and after adjustment, adherence to rhGH was associated with a 0.33 SD (95% confidence interval, 0.10 to 0.56) greater change in height z score. Nonadherence with other medication groups was not significantly associated with a change in height z score.

CONCLUSIONS

Self-reported nonadherence to rhGH was associated with poorer growth velocity in children with CKD, suggesting an opportunity for intervention and improved patient outcome.

Canonical correlation analysis of infant's size at birth and maternal factors: a study in rural northwest Bangladesh

This analysis was conducted to explore the association between 5 birth size measurements (weight, length and head, chest and mid-upper arm [MUAC] circumferences) as dependent variables and 10 maternal factors as independent variables using canonical correlation analysis (CCA). CCA considers simultaneously sets of dependent and independent variables and, thus, generates a substantially reduced type 1 error. Data were from women delivering a singleton live birth (n = 14506) while participating in a double-masked, cluster-randomized, placebo-controlled maternal vitamin A or β-carotene supplementation trial in rural Bangladesh. The first canonical correlation was 0.42 (P<0.001), demonstrating a moderate positive correlation mainly between the 5 birth size measurements and 5 maternal factors (preterm delivery, early pregnancy MUAC, infant sex, age and parity). A significant interaction between infant sex and preterm delivery on birth size was also revealed from the score plot. Thirteen percent of birth size variability was explained by the composite score of the maternal factors (Redundancy, R_Y/X = 0.131). Given an ability to accommodate numerous relationships and reduce complexities of multiple comparisons, CCA identified the 5 maternal variables able to predict birth size in this rural Bangladesh setting. CCA may offer an efficient, practical and inclusive approach to assessing the association between two sets of variables, addressing the innate complexity of interactions.

Do mismatches between pre- and post-natal environments influence adult physiological functioning?

Purpose

Mismatches between pre- and post-natal environments have implications for disease in adulthood. However, less is known about how this mismatch can affect physiological systems more generally, especially at younger ages. We hypothesised that mismatches between pre- and post-natal environments, as measured by the measures of birthweight and adult leg length, would be associated with poorer biomarker levels across five key physiological systems in young adults.

Methods

Data were collected from 923, 36 year-old respondents from the West of Scotland Twenty-07 Study. The biomarkers were: systolic blood pressure (sBP); forced expiratory volume (FEV₁); glycated haemoglobin (HbA_1c); glomerular filtration rate (eGFR); and gamma-glutamyltransferase (GGT). These biomarkers were regressed against pre-natal conditions (birthweight), post-natal conditions (leg length) and the interaction between pre- and post-natal measures. Sex, childhood socioeconomic position and adult lifestyle characteristics were adjusted for as potential effect modifiers and confounders, respectively.

Results

There were no associations between birthweight and leg length and sBP, FEV₁, HbA_1c, or GGT. Higher birthweight and longer leg length were associated with better kidney function (eGFR). However, there was no evidence for mismatches between birthweight and leg length to be associated with worse sBP, FEV₁, HbA_1c, eGFR or GGT levels (P>0.05).

Conclusions

Our hypothesis that early signs of physiological damage would be present in young adults given mismatches in childhood environments, as measured by growth markers, was not proven. This lack of association could be because age 36 is too young to identify significant trends for future health, or the associations simply not being present.

Duration of breastfeeding and gender are associated with methylation of the LEPTIN gene in very young children

BACKGROUND

Perinatal environmental factors have been associated with the metabolic programming of children and consequent disease risks in later life. Epigenetic modifications that lead to altered gene expression may be involved. Here, we study early life environmental and constitutional factors in association with the DNA methylation of leptin (LEP), a non-imprinted gene implicated in appetite regulation and fat metabolism.

METHODS

We investigated maternal education, breastfeeding, and constitutional factors of the child at 17 mo of age. We measured the DNA methylation of LEP in whole blood and the concentration of leptin in serum.

RESULTS

Duration of breastfeeding was negatively associated with LEP methylation. Low education (≤12 y of education) was associated with higher LEP methylation. Boys had higher birth weight and lower LEP methylation than girls. An inverse association was established between birth weight per SD increase (+584 g) and LEP methylation. High BMI and leptin concentration were associated with lower methylation of LEP.

CONCLUSION

The early life environment and constitutional factors of the child are associated with epigenetic variations in LEP. Future studies must reveal whether breastfeeding and the associated decrease in LEP methylation is an epigenetic mechanism contributing to the protective effect of breastfeeding against obesity.