Head circumference at birth and postnatal growth trajectory in vulnerable groups from Argentina

OBJECTIVES

To investigate the association between the anthropometric status at birth and brain and bone growth during the first year of life. According to the brain-sparing hypothesis, we expect catch-up to be faster in head circumference (HC) than in body length.

METHODS

This is a longitudinal design that included Argentinian infants under 12 months of age with at least three anthropometric records. We classified study participants into four growth status categories according to z-scores for HC (HCZ) and length (LAZ) at birth, with z-score = -2 as a threshold. We used the Count model to describe growth trajectories in HC and length in the first year of life according to the growth status at birth. Recovery indicator for HC and length was taken as the time until the predicted growth trajectory surpassed the threshold curve predicted by z-score = -2 for age.

RESULTS

Growth models included 3399 infants. There were significant differences in the growth parameters between groups in all cases (p < 0.05). Within the group with a low HCZ and a low LAZ at birth, HC recovery was faster than length. In the case of a low z-score for only one of the variables, newborns with a low HCZ recovered faster than individuals born with a low LAZ.

CONCLUSIONS

The postnatal growth pattern in HC and length is associated with the growth status of HC and length at birth. As we hypothesized, the fastest postnatal recovery occurs for HC in cases of intrauterine delayed growth.

Fetal and Infancy Exposure to Phenols, Parabens, and Phthalates and Anthropometric Measurements up to 36 Months, in the Longitudinal SEPAGES Cohort

BACKGROUND

Endocrine-disrupting chemicals may play a role in adiposity development during childhood. Until now literature in this scope suffers from methodologic limitations in exposure assessment using one or few urine samples and missing assessment during the infancy period.

OBJECTIVES

We investigated the associations between early-life exposure to quickly metabolized chemicals and post-natal growth, relying on repeated within-subject urine collections over pregnancy and infancy.

METHODS

We studied the associations of four phenols, four parabens, seven phthalates, and one nonphthalate plasticizer from weekly pooled urine samples collected from the mother during second and third trimesters (median 18 and 34 gestational weeks, respectively) and infant at 2 and 12 months of age, and child growth until 36 months. We relied on repeated measures of height, weight and head circumference from study visits and the child health booklet to predict growth outcomes at 3 and 36 months using the Jenss-Bayley nonlinear mixed model. We assessed associations with individual chemicals using adjusted linear regression and mixtures of chemicals using a Bayesian kernel machine regression model.

RESULTS

The unipollutant analysis revealed few associations. Bisphenol S (BPS) at second trimester was positively associated with all infant growth parameters at 3 and 36 months, with similar patterns between exposure at third trimester and all infant growth parameters at 3 months. Mono-n-butyl phthalate (MnBP) at 12 months was positively associated with body mass index (BMI), weight, and head circumference at 36 months. Mixture analysis revealed positive associations between exposure at 12 months and BMI and weight at 36 months, with MnBP showing the highest effect size within the mixture.

CONCLUSIONS

This study suggests that exposure in early infancy may be associated with increased weight and BMI in early childhood, which are risk factors of obesity in later life. Furthermore, this study highlighted the impact of BPS, a compound replacing bisphenol A, which has never been studied in this context. https://doi.org/10.1289/EHP13644.

A modified Michaelis-Menten equation estimates growth from birth to 3 years in healthy babies in the US

Background and Objectives

Standard pediatric growth curves cannot be used to impute missing height or weight measurements in individual children. The Michaelis-Menten equation, used for characterizing substrate-enzyme saturation curves, has been shown to model growth in many organisms including nonhuman vertebrates. We investigated this equation could be used to interpolate missing growth data in children in the first three years of life.

Methods

We developed a modified Michaelis-Menten equation and compared expected to actual growth, first in a local birth cohort (N=97) then in a large, outpatient, pediatric sample (N=14,695).

Results

The modified Michaelis-Menten equation showed excellent fit for both infant weight (median RMSE: boys: 0.22kg [IQR:0.19; 90%<0.43]; girls: 0.20kg [IQR:0.17; 90%<0.39]) and height (median RMSE: boys: 0.93cm [IQR:0.53; 90%<1.0]; girls: 0.91cm [IQR:0.50;90%<1.0]). Growth data were modeled accurately with as few as four values from routine well-baby visits in year 1 and seven values in years 1-3; birth weight or length was essential for best fit.

Conclusions

A modified Michaelis-Menten equation accurately describes growth in healthy babies aged 0-36 months, allowing interpolation of missing weight and height values in individual longitudinal measurement series. The growth pattern in healthy babies in resource-rich environments mirrors an enzymatic saturation curve.

A modified Michaelis-Menten equation estimates growth from birth to 3 years in healthy babies in the US

Background and Objectives

Standard pediatric growth curves cannot be used to impute missing height or weight measurements in individual children. The Michaelis-Menten equation, used for characterizing substrate-enzyme saturation curves, has been shown to model growth in many organisms including nonhuman vertebrates. We investigated this equation could be used to interpolate missing growth data in children in the first three years of life.

Methods

We developed a modified Michaelis-Menten equation and compared expected to actual growth, first in a local birth cohort (N=97) then in a large, outpatient, pediatric sample (N=14,695).

Results

The modified Michaelis-Menten equation showed excellent fit for both infant weight (median RMSE: boys: 0.22kg [IQR:0.19; 90%<0.43]; girls: 0.20kg [IQR:0.17; 90%<0.39]) and height (median RMSE: boys: 0.93cm [IQR:0.53; 90%<1.0]; girls: 0.91cm [IQR:0.50;90%<1.0]). Growth data were modeled accurately with as few as four values from routine well-baby visits in year 1 and seven values in years 1-3; birth weight or length was essential for best fit.

Conclusions

A modified Michaelis-Menten equation accurately describes growth in healthy babies aged 0-36 months, allowing interpolation of missing weight and height values in individual longitudinal measurement series. The growth pattern in healthy babies in resource-rich environments mirrors an enzymatic saturation curve.

Lead Exposure in Infancy and Subsequent Growth in Beninese Children

Studies suggest that elevated postnatal blood lead levels (BLLs) are negatively associated with child growth. This study aimed to investigate the associations of childhood BLLs at age one year and growth outcomes at age six years (n = 661) in a cohort of children in Allada, Benin. The growth outcomes studied are weight-for-age Z-score (WAZ), height-for-age Z-score (HAZ), BMI-for-age Z-score (BMIZ), weight-for-height Z-score (WHZ), head circumference (HC), growth velocities, underweight, stunting, and wasting. Multivariable regression models examined the associations between BLLs and growth outcomes, with adjustment for potential confounders. The geometric mean BLLs was 59.3 μg/L and 82% of children had BLLs >35 μg/L at the age of 12.8 months. After adjusting for confounding factors, no overall association was found between BLL quartiles and HAZ, WAZ, BMIZ, WHZ, growth velocities, wasting, and underweight. However, boys in the highest quartile had a 1.02 cm lower HC (95% CI: [−1.81, −0.24]) as compared to the lowest quartile. Furthermore, an increased odds of being stunted was observed in children in the highest quartile of exposure compared to the first (OR: 2.43; 95% CI: [1.11−5.33]) which remained statistically significant only among girls in sex-specific strata. Blood lead was found to be associated with an increased risk of childhood stunting and a lower head circumference in a resource-limited setting.

Maternal vitamin D status in relation to infant BMI growth trajectories up to 2 years of age in two prospective pregnancy cohorts

Background

Early childhood growth can affect the child's health status later in life. Maternal vitamin D status has been suggested to affect early childhood growth. However, there is a lack of studies investigating the role of maternal vitamin D status on growth trajectories during infancy. By using growth mixture modeling (GMM), maternal vitamin D status during pregnancy can be investigated in relation to different classes of infant growth trajectories.

Objectives

To examine the association between maternal 25-hydroxyvitamin D (25OHD) and classes of infant body mass index (BMI) growth trajectories.

Methods

Mother-child pairs were included from the Norwegian Mother, Father, and Child Cohort Study (MoBa, n = 2522) and the Swedish GraviD cohort (n = 862). Maternal 25OHD in pregnancy was analyzed by liquid chromatography tandem mass spectrometry. Children's weights and heights were registry-based. GMM identified classes of infant BMI growth trajectories up to 2 years. The association between maternal 25OHD and infant BMI class by cohort was estimated using a log-link generalized linear model. Mixed model analysis estimated the pooled association including both cohorts.

Results

Two infant BMI classes were identified, stable normal and stable high. In MoBa, maternal 25OHD <50 and 50-75 nmol/L were associated (RR 2.70, 95% CI 1.26-5.77 and RR 2.56, 95% CI 1.20-5.47) with a higher risk of the infant stable high BMI class, compared with 25OHD >75 nmol/L. In GraviD, no association was found. In pooled analysis, maternal 25OHD ≤75 nmol/L was non-significantly associated with a higher risk of the stable high BMI growth class.

Conclusions

Maternal 25OHD ≤75 nmol/L may be associated with a higher class of BMI growth trajectory during infancy.

Associations between maternal eating behaviors and feeding practices in toddlerhood

Few studies have examined the associations between parents' own eating behaviors and their feeding practices. We aimed to study the associations between maternal eating behaviors and feeding practices in toddlerhood. In this cross-sectional analysis, maternal eating behaviors and feeding practices were assessed at 2-year follow-up by using the Three-Factor Eating Questionnaire (TFEQ-R21) and the Comprehensive Feeding Practices Questionnaire (CFPQ), respectively, among mothers of 1322 children from the EDEN mother-child cohort. Depending on their distributions, scores from the two questionnaires were considered continuous or binary variables, according to the median. Linear or logistic regression models were used as appropriate to assess the associations between maternal eating behaviors, considered simultaneously in a combined model, and their feeding practices. Maternal cognitive restraint was positively associated with maternal restriction for health and restriction for weight. Maternal uncontrolled eating was positively associated with pressure to eat and use of food to regulate the child's emotions. Maternal uncontrolled eating was also negatively associated with restriction for weight, but only among boys. This study supports that mothers' own eating behaviors are associated with their feeding practices in toddlerhood. Further studies are needed to understand the role of parental feeding practices in the familial transmission of eating behavior.

Infant feeding practices associated with adiposity peak and rebound in the EDEN mother-child cohort

BACKGROUND/OBJECTIVE

High magnitude of adiposity peak and early adiposity rebound are early risk markers of later obesity. Infant diet represents one of the main modifiable determinants of early growth. This study aimed to investigate the association between infant feeding practices and age and magnitude of adiposity peak and rebound.

SUBJECTS/METHODS

Analyses were based on data from the French EDEN mother-child cohort. Data on breastfeeding and complementary feeding were collected at birth and 4, 8, and 12 months. From clinical examinations and measurements collected in the child's health booklet up to 12 years, individual growth curves were modeled, and ages and magnitudes of adiposity peak and rebound were estimated. Associations between infant feeding practices and growth were investigated by multivariable linear regression in children after testing a child-sex interaction.

RESULTS

In the studied population (n = 1225), adiposity peak occurred at a mean of 9.9 ± 2 months and adiposity rebound at 5.5 ± 1.4 years. Associations between infant feeding practices and adiposity peak or rebound were moderated by child sex. For girls, each additional month of breastfeeding was related to a 2-day increase in the age at adiposity peak (p < 0.001), and an 18-day increase in the age at adiposity peak (p = 0.004). Whereas for boys, each additional month for the age at complementary food introduction was associated with a 29-day increase in the age at adiposity rebound (p = 0.02). For boys, long breastfeeding duration was only related to reduced body mass index at adiposity peak.

CONCLUSIONS

Child sex has a moderating effect on the association between infant feeding practices and adiposity peak or rebound. The well-known association between breastfeeding duration and early growth seems stronger in girls than boys. The association found for complementary feeding in boys may give new insights into preventing obesity.

Novel type of references for weight aligned for onset of puberty - using the QEPS growth model

BACKGROUND

Growth references are traditionally constructed relative to chronological age, despite inter-individual variations in pubertal timing. A new type of height reference was recently developed allowing growth to be aligned based on onset of pubertal height growth. We here aim to develop a corresponding reference for pubertal weight.

METHODS

To model QEPS-weight, 3595 subjects (1779 girls) from GrowUp1974Gothenburg and GrowUp1990Gothenburg were used. The QEPS-height-model was transformed to a corresponding QEPS-weight-model; thereafter, QEPS-weight was modified by an individual, constitutional weight-height-factor. Longitudinal weight and length/height measurements from 1418 individuals (698 girls) from GrowUp1990Gothenburg were then used to create weight references aligned for height at pubertal onset (the age at 5% of P-function growth, AgeP5). GrowUp1974Gothenburg subgroups based on pubertal timing, stature at pubertal onset, and childhood body composition were assessed using the references.

RESULTS

References (median, SDS) for total weight (QEPS-functions), weight specific to puberty (P-function), and weight gain in the absence of specific pubertal growth (basic weight, QES-functions), allowing alignment of individual growth based on age at pubertal onset. For both sexes, basic weight was greater than average for late maturing, tall and high-BMI subgroups. The P-function-related weight was greater than average in short and lower than average in tall children, in those with high BMI, and in girls but not boys with low BMI.

CONCLUSIONS

New pubertal weight references allow individual variations in pubertal timing to be taken into consideration when evaluating growth. When used together with the comparable pubertal height reference, this will improve growth monitoring in clinical practice for identifying abnormal growth and serve as a valuable research tool providing insight into human growth.

Early postnatal growth and subsequent neurodevelopment in children delivered at term: The ELFE cohort study

BACKGROUND

Despite the limited evidence, accelerated early postnatal growth (EPG) is commonly believed to benefit neurodevelopment for term-born infants, especially those small for gestational age.

OBJECTIVES

To investigate the existence of critical time windows in the association of EPG with neurodevelopment, considering birth size groups.

STUDY DESIGN

In the French ELFE birth cohort, 12,854 term-born neonates were classified as small, appropriate or large for gestational age (SGA, AGA, LGA, respectively). Parents reported their child's development by using the Child Development Inventory (CDI-score) at age 12 months and the MacArthur-Bates Development Inventory (MAB-score; 100 score units) assessing language ability at age 24 months. Predictions of individual weight, body mass index (BMI), length, and head circumference (HC) from birth to age 24 months were obtained from repeated measurements fitted with the Jenss-Bayley mixed-effects model. For each infant, conditional gains (CG) in these growth parameters were generated at four-time points (3, 6, 12 and 24 months) representing specific variations in growth parameters during 0-3, 3-6, 6-12, 12-24 months, independent of previous measures. Using multivariable linear regression models, we provided the estimate differences of the neurodevelopmental scores according to variation of each growth parameter CG, by birth size group.

RESULTS

For SGA infants, the MAB-score differed by 5.8 (95% confidence interval [CI] -0.2, 11.8), 6.7 (95% CI -0.1, 13.3), and 9.7 (95% CI 1.9, 17.5) score units when CG in BMI, weight, and HC at 3 months varied from -2 to 1 standard deviation, respectively. For all infants, MAB-score was linearly and positively associated with length conditional gains at 12 months, with stronger magnitude for SGA infants. Results for the CDI-score were overall consistent with those for MAB-score.

CONCLUSIONS

For term-born SGA infants, moderate catch-up in HC, BMI and weight within the first 3 months of life may benefit later neurodevelopment, which could guide clinicians to monitor EPG.

Maternal seafood intake during pregnancy, prenatal mercury exposure and child body mass index trajectories up to 8 years

BACKGROUND

Maternal seafood intake during pregnancy and prenatal mercury exposure may influence children's growth trajectories.

METHODS

This study, based on the Norwegian Mother, Father and Child Cohort Study (MoBa), includes 51 952 mother-child pairs recruited in pregnancy during 2002-08 and a subsample (n = 2277) with maternal mercury concentrations in whole blood. Individual growth trajectories were computed by modelling based on child's reported weight and length/height from 1 month to 8 years. We used linear mixed-effects regression analysis and also conducted discordant-sibling analysis.

RESULTS

Maternal lean fish was the main contributor to total seafood intake in pregnancy and was positively but weakly associated with child body mass index (BMI) growth trajectory. Higher prenatal mercury exposure (top decile) was associated with a reduction in child's weight growth trajectory, with the estimates ranging from -130 g [95% Confidence Intervals (CI) = -247, -12 g] at 18 months to -608 g (95% CI = -1.102, -113 g) at 8 years. Maternal fatty fish consumption was positively associated with child weight and BMI growth trajectory, but only in the higher mercury-exposed children (P-interaction = 0.045). Other seafood consumption during pregnancy was negatively associated with child weight growth compared with no intake, and this association was stronger for higher mercury-exposed children (P-interaction = 0.004). No association was observed between discordant maternal seafood intake and child growth in the sibling analysis.

CONCLUSIONS

Within a population with moderate seafood consumption and low mercury exposure, we found that maternal seafood consumption in pregnancy was associated with child growth trajectories, and the direction of the association varied by seafood type and level of prenatal mercury exposure. Prenatal mercury exposure was negatively associated with child growth. Our findings on maternal seafood intake are likely non-causal.

Early childhood growth trajectory and later cognitive ability: evidence from a large prospective birth cohort of healthy term-born children

BACKGROUND

Most studies of associations between child growth and cognitive ability were based on size at one or two ages and a single measure of cognition. We aimed to characterize different aspects of early growth and their associations with cognitive outcomes in childhood through adolescence.

METHODS

In a sample of 12 368 Belarusian children born at term, we examined associations of length/height and weight trajectories over the first 6.5 years of life with cognitive ability at 6.5 and 16 years and its change over time. We estimated growth trajectories using two random-effects models-the SuperImposition by Translation and Rotation to model overall patterns of growth and the Jenss-Bayley to distinguish growth in infancy from post infancy. Cognitive ability was measured using the Wechsler Abbreviated Scales of Intelligence at 6.5 years and the computerized NeuroTrax test at 16 years.

RESULTS

Higher length/height between birth and 6.5 years was associated with higher cognitive scores at 6.5 and 16 years {2.7 points [95% confidence interval (CI): 2.1, 3.2] and 2.5 points [95% CI: 1.9, 3.0], respectively, per standard deviation [SD] increase}. A 1-SD delay in the childhood height-growth spurt was negatively associated with cognitive scores [-2.4 (95% CI: -3.0, -1.8) at age 6.5; -2.2 (95% CI: -2.7, -1.6) at 16 years]. Birth size and post-infancy growth velocity were positively associated with cognitive scores at both ages. Height trajectories were not associated with the change in cognitive score. Similar results were observed for weight trajectories.

CONCLUSIONS

Among term infants, the overall size, timing of the childhood growth spurt, size at birth and post-infancy growth velocity were all associated with cognitive ability at early-school age and adolescence.

Comparison of growth models to describe growth from birth to 6 years in a Beninese cohort of children with repeated measurements

OBJECTIVE

To select a growth model that best describes individual growth trajectories of children and to present some growth characteristics of this population.

SETTINGS

Participants were selected from a prospective cohort conducted in three health centres (Allada, Sekou and Attogon) in a semirural region of Benin, sub-Saharan Africa.

PARTICIPANTS

Children aged 0 to 6 years were recruited in a cohort study with at least two valid height and weight measurements included (n=961).

PRIMARY AND SECONDARY OUTCOME MEASURES

This study compared the goodness-of-fit of three structural growth models (Jenss-Bayley, Reed and a newly adapted version of the Gompertz growth model) on longitudinal weight and height growth data of boys and girls. The goodness-of-fit of the models was assessed using residual distribution over age and compared with the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). The best-fitting model allowed estimating mean weight and height growth trajectories, individual growth and growth velocities. Underweight, stunting and wasting were also estimated at age 6 years.

RESULTS

The three models were able to fit well both weight and height data. The Jenss-Bayley model presented the best fit for weight and height, both in boys and girls. Mean height growth trajectories were identical in shape and direction for boys and girls while the mean weight growth curve of girls fell slightly below the curve of boys after neonatal life. Finally, 35%, 27.7% and 8% of boys; and 34%, 38.4% and 4% of girls were estimated to be underweight, wasted and stunted at age 6 years, respectively.

CONCLUSION

The growth parameters of the best-fitting Jenss-Bayley model can be used to describe growth trajectories and study their determinants.

Does cord blood leptin level mediate the association between neonatal body size and postnatal growth? Results from the EDEN mother-child cohort study

Background: Leptin is potentially involved in the correction of early postnatal growth of infants having deviated from their genetic trajectory in utero.Aim: To analyse the potential mediating role of cord blood leptin level in the association between neonatal anthropometry and early postnatal growth in the mother-child EDEN cohort.Subjects and methods: We included term newborns with information on leptin, birth weight and length, and weight and length SD-score changes over the first 2 months. The Baron and Kenny method was used to quantify the mediation contribution of leptin in the association between neonatal anthropometry and postnatal growth, considering several confounders. Analyses were stratified to consider sexual dimorphism.Results: A 1 SD higher birth weight was associated with a lower 2-months weight variation of 0.27 (0.18; 0.36) SD and a 0.16 (0.06; 0.26) SD, in boys and girls, respectively. Leptin explained 20% and 25% of these associations, respectively. Leptin did not mediate the association between birth length and birth-to-2 months length variation.Conclusion: Our results suggest that cord blood leptin may not be involved in the negative association between birth length and postnatal length growth but may play a modest mediating role in early postnatal catch-up or catch-down in weight.

Measuring Child Socio-Economic Position in Birth Cohort Research: The Development of a Novel Standardized Household Income Indicator

The assessment of early life socioeconomic position (SEP) is essential to the tackling of social inequalities in health. Although different indicators capture different SEP dimensions, maternal education is often used as the only indicator in birth cohort research, especially in multi-cohort analyses. Household income, as a direct measure of material resources, is one of the most important indicators, but one that is underused because it is difficult to measure through questionnaires. We propose a method to construct a standardized, cross-cohort comparable income indicator, the “Equivalized Household Income Indicator (EHII)”, which measures the equivalized disposable household income, using external data from the pan-European Union Statistics on Income and Living Conditions (EUSILC) surveys, and data from the cohorts. We apply this method to four studies, Piccolipiù and NINFEA from Italy and ELFE and EDEN from France, comparing the distribution of EHII with other SEP-related variables available in the cohorts, and estimating the association between EHII and child body mass index (BMI). We found that basic parental and household characteristics may be used, with a fairly good performance, to predict the household income. We observed a strong correlation between EHII and both the self-reported income, whenever available, and other individual socioeconomic-related variables, and an inverse association with child BMI. EHII could contribute to improving research on social inequalities in health, in particular in the context of European birth cohort collaborative studies.

Which modifiable prenatal factors mediate the relation between socio-economic position and a child's weight and length at birth?

Although several studies have shown a positive association between socio-economic position and size at birth, not enough is known about the modifiable factors that may be involved. We aimed to investigate whether maternal prepregnancy body mass index (BMI), smoking, diet, and depression during pregnancy mediate the positive association between maternal education and birth size. Weight and length z-scores specific for gestational age and sex were calculated for 1,500 children from the EDEN mother-child cohort. A mediation analysis of the associations between maternal education and birth size was conducted with a counterfactual method, adjusted for recruitment centre, parity, maternal height, and age. In the comparison of children of mothers with low versus intermediate education levels, maternal smoking during pregnancy explained 52% of the total effect of education on birth weight. Similar findings were observed with birth length z-score (37%). The comparison of children of mothers with high versus intermediate education levels yielded a non-significant total effect, which masked opposite mediating effects by maternal BMI and smoking during pregnancy on both birth weight and length. Prepregnancy BMI and maternal smoking during pregnancy mediate the positive association between maternal education and birth weight and length z-scores. These mediators, however, act in opposite directions, thereby masking the extent to which healthy prenatal growth is socially differentiated.

Association between genetic obesity susceptibility and mother-reported eating behaviour in children up to 5 years

BACKGROUND

Many genetic polymorphisms identified by genome-wide association studies for adult body mass index (BMI) have been suggested to regulate food intake.

OBJECTIVE

The objective was to study the associations between a genetic obesity risk score, appetitive traits, and growth of children up to age 5 years, with a longitudinal design.

METHODS

In 1142 children from the Etude des Déterminants pre et post natals de la santé de l'ENfant (EDEN) birth cohort, a combined obesity risk-allele score (BMI genetic risk score [GRS]) was related to appetitive traits (energy intake up to 12 mo, a single item on appetite from 4 mo to 3 y, a validated appetite score at 5 y) using Poisson regressions with robust standard errors. The potential mediation of appetitive traits on the association between BMI-GRS and growth was assessed by the Sobel test.

RESULTS

Children with a high BMI-GRS were more likely to have high energy intake at 1 year and high appetite at 2 and 5 years. High energy intake in infancy and high appetite from 1 year were related to higher subsequent BMI. High 2-year appetite seemed to partially mediate the associations between BMI-GRS and BMI from 2 to 5 years (all P ≤ 0.05).

CONCLUSIONS

Genetic susceptibility to childhood obesity seems to be partially explained by appetitive traits in infancy, followed by an early childhood rise in BMI.

Impact of parental weight status on children's body mass index in early life: evidence from a Chinese cohort

OBJECTIVES

To understand whether parents' weight status before conception predicts body mass index (BMI) of their offspring in early life and the differences between the mother-child and father-child associations.

DESIGN

A birth cohort study.

SETTING

Conducted at the Community Health Service Centre in Shenyang, Wuhan and Guangzhou.

PARTICIPANTS

A total of 2220 live birth newborns were recruited randomly after consent of their parents, and 1178 were followed up until 2 years old.

METHODS

Parental demographics, maternal characteristics during pregnancy, children's anthropometric data and feeding patterns at 1 month old were collected. BMI was calculated and BMI Z-scores (BMI_Z) were generated by referring to WHO growth standard. Parental weight status was categorised into underweight, normal weight, and overweight and obese according to the Working Group of Obesity in China. General linear models and generalised linear models were used to assess the associations between parents and offspring.

OUTCOME MEASURES

The primary outcomes were descriptive data on child's sex-specific anthropometric variables. The secondary outcomes were BMI_Z and weight status of children at each time point.

RESULTS

No gender difference was observed in BMI_Z or overweight or obesity rates from birth to 24 months old, although boys were significantly heavier and had a greater length/height than girls (P<0.05). The overweight and obesity rates of children peaked at 12 months old. Maternal BMI/weight status had a significant but small effect on BMI_Z at birth, but not on the paternal side. The impact of parental BMI on child's BMI_Z after birth was similar at each follow-up. Offspring with underweight mothers tend to have reduced BMI_Z after birth while overweight/obese fathers had children with a greater BMI_Z.

CONCLUSIONS

Maternal weight status had small effect on both fetal and child growth after birth. Significant but mild paternal influence was only detected after birth.

Dietary acrylamide intake during pregnancy and postnatal growth and obesity: Results from the Norwegian Mother and Child Cohort Study (MoBa)

BACKGROUND

Prenatal acrylamide exposure has been negatively associated with fetal growth but the association with child growth is unknown.

OBJECTIVES

We studied the association between prenatal acrylamide exposure and child postnatal growth up to 8 years in the Norwegian Mother and Child Cohort Study (MoBa).

METHODS

In 51,952 mother-child pairs from MoBa, acrylamide intake during pregnancy was estimated by combining maternal food intake with food concentrations of acrylamide. Mothers reported their child's weight and length/height up to 11 times between 6 weeks and 8 years. Weight and height growth trajectories were modelled using Jenss-Bayley's growth model. Logistic regression models were used to study the association with overweight/obese status at 3, 5 and 8 years, as identified using the International Obesity Task Force cut-offs. Linear mixed-effect models were used to explore associations with overall growth.

RESULTS

At 3 years, the adjusted odds ratios (95% Confidence Intervals (CI)) of being overweight/obese were 1.10 (1.02, 1.20), 1.12 (1.04, 1.22) and 1.21 (1.11, 1.31) by increasing prenatal acrylamide exposure quartile. Similar dose-response associations were found at 5 and 8 years. Acrylamide intake during pregnancy was associated with higher weight growth velocity in childhood. Children exposed at the highest level had 22 g (95% CI: 8, 37), 57 g (95% CI: 32, 81), and 194 g (95% CI: 110, 278) higher weight at 0.5, 2, and 8 years, respectively, compared to their low exposed peers.

CONCLUSIONS

Children prenatally exposed to acrylamide in the highest quartile experienced a moderate increase in weight growth velocity during early childhood that resulted in a moderately increased prevalence of overweight/obesity compared to peers in the lowest quartile. Our study is the first to link prenatal acrylamide exposure and postnatal growth.

Joint Bayesian weight and height postnatal growth model to study the effects of maternal smoking during pregnancy

Growth models used for describing the dynamics of body weight and height generally consider each trait independently. We proposed modeling height and weight trajectories jointly with a nonlinear heteroscedastic mixed model based on the Jenss-Bayley growth function with correlated individual random effects and using Bayesian inference techniques. Simulations showed that our model provides good estimates of the growth parameters. We illustrated how it can be used to assess the associations between maternal smoking during pregnancy, an early-life factor potentially involved in prenatal programming of obesity, and children's growth from birth to 5 years of age. We used real data from the EDEN study, a large French mother-child cohort study with a high number of height and weight measurements (a total of approximately 30 000 measurements for each of the 2 traits across the 1666 children). Our results supported the existence of a relationship between maternal smoking during pregnancy and growth from birth to 5 years of age. Children from mothers who smoked throughout pregnancy were shown to display a higher body mass index from the first few months of life onwards compared to children from nonsmokers. At 5 years of age, their mean body mass index was 0.21 kg/m² higher than unexposed children. It was mainly explained by the fact that these children tended to be smaller at birth but rapidly exceeded the weight of children from nonsmokers postnatally.

Influence of infant feeding patterns over the first year of life on growth from birth to 5 years

OBJECTIVES

As early-life feeding experiences may influence later health, we aimed to examine relations between feeding patterns over the first year of life and child's growth in the first 5 years of life.

METHODS

Our analysis included 1022 children from the EDEN mother-child cohort. Three feeding patterns were previously identified, i.e. 'Later dairy products introduction and use of ready-prepared baby foods' (pattern-1), 'Long breastfeeding, later main meal food introduction and use of home-made foods' (pattern-2) and 'Use of ready-prepared adult foods' (pattern-3). Associations between the feeding patterns and growth [weight, height and body mass index {BMI}] were analysed by multivariable linear regressions. Anthropometric changes were assessed by the final value adjusted for the initial value.

RESULTS

Even though infant feeding patterns were not related to anthropometric measurements at 1, 3 and 5 years, high scores on pattern-1 were associated with higher 1-3 years weight and height changes. High scores on pattern-2 were related to lower 0-1 year weight and height changes, higher 1-5 years weight and height changes but not to BMI changes, after controlling for a wide range of potential confounding variables including parental BMI. Scores on pattern-3 were not significantly related to growth. Additional adjustment for breastfeeding duration reduced the strength of the associations between pattern-2 and growth but not those between pattern-1 and height growth.

CONCLUSION

Our findings emphasize the relevance of considering infant feeding patterns including breastfeeding duration, age of complementary foods introduction as well as type of foods used when examining effects of early infant feeding practices on later health. © 2017 World Obesity Federation.

Maternal plasma phosphatidylcholine polyunsaturated fatty acids during pregnancy and offspring growth and adiposity

BACKGROUND

Polyunsaturated fatty acids (PUFA) are essential for offspring development, but it is less clear whether pregnancy PUFA status affects growth and adiposity.

METHODS

In 985 mother-offspring pairs from the ongoing Singaporean GUSTO cohort, we analyzed the associations between offspring growth and adiposity outcomes until age 5 years and five PUFAs of interest, measured in maternal plasma at 26-28 weeks' gestation: linoleic acid (LA), arachidonic acid, α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid (DHA). We measured fetal growth by ultrasound (n=924), neonatal body composition (air displacement plethysmography (n=252 at birth, and n=317 at age 10 days), and abdominal magnetic resonance imaging (n=317)), postnatal growth (n=979) and skinfold thicknesses (n=981). Results were presented as regression coefficients for a 5% increase in PUFA levels.

RESULTS

LA levels were positively associated with birthweight (β (95% CI): 0.04 (0.01, 0.08) kg), body mass index (0.13 (0.02, 0.25) kg/m²), head circumference (0.11 (0.03, 0.19) cm), and neonatal abdominal adipose tissue volume (4.6 (1.3, 7.8) mL for superficial subcutanous tissue, and 1.2 (0.1, 2.4) mL for internal tissue), but not with later outcomes. DHA levels, although not associated with birth outcomes, were related to higher postnatal length/height: 0.63 (0.09, 1.16) cm at 12 months and 1.29 (0.34, 2.24) cm at 5 years.

CONCLUSIONS

LA was positively associated with neonatal body size, and DHA with child height. Maternal PUFA status during pregnancy may influence fetal and child growth and adiposity.

Phthalate pregnancy exposure and male offspring growth from the intra-uterine period to five years of age

OBJECTIVE

To study associations between prenatal exposure to phthalates and fetal and postnatal growth up to age 5 years in male offspring.

METHODS

Eleven phthalate metabolites were quantified in spot maternal urine samples collected during gestation among 520 women of the EDEN mother-child cohort who gave birth to a boy. Fetal growth was assessed from repeated ultrasound measurements and measurements at birth. We used repeated measures of weight and height in the first 5 years of life to model individual postnatal growth trajectories. We estimated adjusted variations in pre and postnatal growth parameters associated with an interquartile range increase in ln-transformed phthalate metabolite concentrations.

RESULTS

Monocarboxyisononyl phthalate (MCNP) was positively associated with femoral length during gestation and length at birth. High molecular weight phthalate metabolites were negatively associated with estimated fetal weight throughout pregnancy. Monoethyl phthalate (MEP) showed positive association with weight growth velocity from two to five years and with body mass index at five years (β=0.17kg/m², 95% confidence interval, 0.04, 0.30).

CONCLUSIONS

We highlighted associations between gestational exposure to some phthalates and growth in boys. The positive association between MEP and postnatal growth in boys was also reported in several previous human studies.

Rapid Early Growth May Modulate the Association Between Birth Weight and Blood Pressure at 5 Years in the EDEN Cohort Study

Physiological evidence suggests that birth weight (BW) and postnatal growth affect blood pressure (BP) level, independently or in interaction. Their respective roles are difficult to disentangle in epidemiological studies, however, especially when adjusting for final weight. We assessed the portion of the effect of BW on BP at 5 years that was not attributable to postnatal growth and investigated potential interactions between BW and postnatal growth velocity at different time points in the EDEN mother-child study. Collecting a median of 19 weight measurements for each of the 1119 children who completed follow-up enabled us to model instantaneous growth velocity at any age. After computing a BP SD-score at 5 years, adjusted for age, sex, current body mass index, and height, we used multiple linear regression to study its association with age- and sex-specific BW z score, adjusting for several maternal and pregnancy risk factors. We tested interactions between BW categories (small-, appropriate-, and large-for-gestational-age) and weight growth velocities at different ages. The BW z score was negatively and significantly correlated with the systolic BP SD-score at the age of 5 years (r=-0.07, P=0.02). Interactions were found between BW categories and weight growth velocities from 1 to 4 months (P from 0.002 to 0.08) but not at older ages; specifically, children born small for gestational age with a fast weight growth velocity in their first few months of life had the highest absolute systolic BP and SD score values at 5 years. They may need monitoring for cardiovascular risks.

Prospective associations between energy balance-related behaviors at 2 years of age and subsequent adiposity: the EDEN mother-child cohort

BACKGROUND/OBJECTIVES

Sedentary behavior, physical activity and dietary behavior are formed early during childhood and tend to remain relatively stable into later life. No longitudinal studies have assessed the independent influence of these three energy balance-related behaviors during toddlerhood on later adiposity. We aimed to analyze the associations between TV/DVD watching time, outdoor play time and dietary patterns at the age of 2 years and child adiposity at the age of 5 years, in boys and girls separately.

SUBJECTS/METHODS

This study included 883 children from the French EDEN mother-child cohort. TV/DVD watching time, outdoor play time and dietary intakes were reported by parents in questionnaires when the child was aged 2 years. Two dietary patterns, labeled 'Guidelines' and 'Processed, fast foods', were identified in a previous study. The percentage of body fat (%BF) based on bioelectrical impedance analysis and body mass index were measured at the age of 5 years.

RESULTS

In boys, TV/DVD watching time at the age of 2 years was positively associated with %BF at the age of 5 years (β=0.50 (95% confidence interval: 0.001, 1.00) for those boys with ⩾60 min per day of TV/DVD watching time vs those with ⩽15 min per day, P-value for trend 0.05). In girls, outdoor play was inversely associated with %BF (β=-0.96 (95% confidence interval: -1.60, -0.32) for those in the highest tertile of outdoor play time vs those in the lowest tertile, P=0.001). Overall, at the age of 2 years, dietary patterns were associated with both TV/DVD watching time and outdoor play time, but no significant and independent association was observed between dietary patterns and later adiposity.

CONCLUSION

This study shows longitudinal and gender-differentiated relations between both TV/DVD watching time and outdoor play time in toddlerhood and later adiposity, whereas evidence for a relation between dietary patterns and subsequent fat development was less conclusive. Early childhood-by the age of 2 years-should be targeted as a critical time for promoting healthy energy balance-related behaviors.

A Novel Method to Describe Early Offspring Body Mass Index (BMI) Trajectories and to Study Its Determinants

Background

Accurately characterizing children’s body mass index (BMI) trajectories and studying their determinants is a statistical challenge. There is a need to identify early public health measures for obesity prevention. We describe a method that allows studies of the determinants of height, weight and BMI growth up to five years of age. We illustrated this method using maternal smoking during pregnancy as one of the early-life factors that is potentially involved in prenatal programming of obesity.

Methods

Individual height and weight trajectories were fitted using the Jenss-Bayley model on 28,381 and 30,515 measurements, respectively, from 1,666 children to deduce BMI trajectories. We assessed global associations between smoking and growth trajectories and cross-sectional associations at specific ages.

Results

Children exposed in late pregnancy had a 0.24 kg/m² (95% confidence interval: 0.07, 0.41) higher BMI at 5 years of age compared with non-exposed children. Although the BMIs of children exposed during late pregnancy became significantly higher compared with those of non-exposed children from 2 years onwards, the trajectories began to diverge during the first weeks of life.

Conclusion

Our method is relevant for studies on the relationships between individual-level exposures and the dynamics and shapes of BMI growth during childhood, including key features such as instantaneous growth velocities and the age or BMI value at the BMI infancy peak that benefit from the monotonic pattern of height and weight growth.

Growth pattern from birth to adulthood in African pygmies of known age

The African pygmy phenotype stems from genetic foundations and is considered to be the product of a disturbance in the growth hormone–insulin-like growth factor (GH–IGF) axis. However, when and how the pygmy phenotype is acquired during growth remains unknown. Here we describe growth patterns in Baka pygmies based on two longitudinal studies of individuals of known age, from the time of birth to the age of 25 years. Body size at birth among the Baka is within standard limits, but their growth rate slows significantly during the first two years of life. It then more or less follows the standard pattern, with a growth spurt at adolescence. Their life history variables do not allow the Baka to be distinguished from other populations. Therefore, the pygmy phenotype in the Baka is the result of a change in growth that occurs during infancy, which differentiates them from East African pygmies revealing convergent evolution.

The African pygmies are known for their short stature, yet it is unclear when and how this phenotype is acquired during growth. Here the authors show that the pygmies' small stature results primarily from slow growth during infancy.

Importance of characterizing growth trajectories

In the era of the obesity epidemic in children, characterizing childhood growth trajectories (weight, length/height, or body mass index/weight for length) is becoming essential for surveillance. Clinicians routinely use growth curves to identify abnormal growth trajectories. Clinical epidemiologists are interested in both the determinants of growth and the consequences of certain patterns of growth on later health and diseases. Characterizing growth trajectories is also helpful to predict future growth based on past growth and might be useful in the future to compare the impact of various interventions.

Comparative study of four growth models applied to weight and height growth data in a cohort of US children from birth to 9 years

BACKGROUND/AIMS

The objective of our study was to compare the fit of four growth models for weight and height in contemporary US children between birth and 9 years.

METHODS

In Project Viva, we collected weight and height growth data between birth and 9 years. We compared the Jenss model, the adapted Jenss model that adds a quadratic term, and the Reed 1st and 2nd order models. We used the log likelihood ratio test to compare nested models and the Akaike (AIC)/Bayesian information criterion (BIC) to compare nonnested models.

RESULTS

For weight and height, the adapted Jenss model had a better fit than the Jenss model (for weight: p < 0.0001), and the Reed 2nd order model had a better fit than the Reed 1st order model (for weight: p < 0.0001). Compared with the Reed 2nd order model, the adapted Jenss model had a better fit for both weight (adapted Jenss vs. Reed 2nd order, AIC: 66,974 vs. 82,791, BIC: 67,066 vs. 82,883) and height (adapted Jenss vs. Reed 2nd order, AIC: 87,108 vs. 87,612, BIC: 87,196 vs. 87,700).

CONCLUSIONS

In this pre-birth study of children aged 0-9 years, for both weight and height the adapted Jenss model presented the best fit of all four tested models.