Fast, Slow, High, and Low: Infant and Childhood Growth as Predictors of Cardiometabolic Outcomes

Early childhood body mass index growth and school readiness: A longitudinal cohort study

BACKGROUND

Child growth influences future health and learning. School readiness refers to a child's ability to meet developmental expectations at school entry. The association of early growth rate and patterns with school readiness remains unknown.

OBJECTIVE

To determine the association of child body mass index (BMI) growth with school readiness in a cohort of young children.

METHODS

A prospective cohort study (2015-2022) was conducted in children 0-6 years enrolled in the TARGet Kids! research network in Toronto, Canada. Two analytical approaches were used to measure growth using child weight and height/length data between 0 and 4 years: (i) age- and sex-standardised BMI (zBMI) growth rate per year using a piecewise linear model; and (ii) distinct zBMI trajectories using latent class mixed models. School readiness (4-6 years) was measured using teacher-completed Early Development Instrument (EDI). Robust Poisson models and marginal linear models using generalised estimating equations were used adjusting for confounders identified a priori.

RESULTS

In this study of 1077 children (mean age at EDI completion: 4.8 years; 52.6% male) with 6415 zBMI measurements, mean growth rate was 0.65 zBMI units/year (0-2 years) and -0.11 zBMI units/year (2-4 years). Two distinct zBMI trajectories were identified: the stable trajectory and the catch-up trajectory. There was insufficient evidence that zBMI growth rates (risk ratio 1.10, 95% confidence interval 0.78, 1.55 for 0-2 years; risk ratio 0.71, 95% confidence interval 0.32, 1.57 for 2-4 years) or trajectories (risk ratio 1.05, 95% confidence interval 0.82, 1.35, catch-up trajectory vs. stable trajectory) were associated with school readiness.

CONCLUSIONS

No association was found between BMI growth and school readiness. School readiness may be more impacted by factors directly related to obesity or adiposity at the time of EDI measurement rather than growth.

Timing and Magnitude of Peak Body Mass Index and Peak Weight Velocity in Infancy Predict Body Mass Index at 2 Years in a Retrospective Cohort of Electronic Health Record Data

OBJECTIVES

To use growth data from electronic health records to describe and model infant growth (weight velocity and peak body mass index [pBMI]) characteristics.

STUDY DESIGN

We extracted data from all children born at ≥34 weeks of gestation within one health system between 2014 and 2017. After excluding implausible growth data with an algorithm created for childhood growth, we estimated pBMI, peak weight and length velocities, and the odds of obesity at 2 years, adjusted for race, sex, ethnicity, and birth weight, by the magnitude of peak weight velocity, peak length velocity, and pBMI.

RESULTS

Among 6425 children (41% White, 28% Black, 26% other race; 16% Hispanic ethnicity), mean pBMI was 17.9 kg/m² (SD 1.5) and mean age at pBMI was 9.6 months (SD 2.7). Mean peak weight velocity was 949 g (SD 165) per 2 weeks, and the mean peak length velocity was 3.4 cm (SD 0.3) per 2 weeks. Children with obesity at 2 years (n = 931, 14.5%) were more likely to be Hispanic, had greater peak weight and peak length velocities, and had 2 kg/m² greater magnitude of pBMI than children without obesity. For each unit increase in pBMI, children had more than 4 times greater odds of obesity at age 2 years.

CONCLUSIONS

In a large sample of infants with clinical growth data tracked via electronic health records, we found associations between the magnitude and timing of peak infant BMI and obesity at 2 years of age.

Effects of Breastfeeding, Formula Feeding, and Complementary Feeding on Rapid Weight Gain in the First Year of Life

OBJECTIVE

To determine whether proportion of breast versus formula feeding and timing of complementary food introduction affect the odds of rapid gain in weight status in a diverse sample of infants.

METHODS

Using data from Greenlight Intervention Study, we analyzed the effects of type of milk feeding (breastfeeding, formula, or mixed feeding) from the 2- to 6-month well visits, and the introduction of complementary foods before 4 months on rapid increase in weight-for-age z-score (WAZ) and weight-for-length z-score (WLZ) before 12 months using multivariable logistic regression models.

RESULTS

Of the 865 infants enrolled, 469 had complete data on all variables of interest, and 41% and 33% of those infants had rapid increases in WAZ and WLZ, respectively. Odds of rapid increase in WAZ remained lowest for infants breastfeeding from 2 to 6 months (adjusted odds ratio [aOR] 0.34; 95% confidence interval [CI]: 0.17, 0.69) when compared to infants who were formula-fed. Adjusted for feeding, introduction of complementary foods after 4 months was associated with decreased odds of rapid increase in WLZ (aOR 0.64; 95% CI: 0.42, 0.96).

CONCLUSIONS

Feeding typified by predominant breastfeeding and delaying introduction of complementary foods after 4 months reduces the odds of rapid increases in WAZ and WLZ in the first year of life.

Increased blood pressure and impaired endothelial function after accelerated growth in IVF/ICSI children

STUDY QUESTION

What is the effect of growth velocity (height and weight) in early infancy on metabolic end-points and endothelial function in children born after ART?

SUMMARY ANSWER

Neonatal, infant and childhood growth is positively related to blood pressure in 9-year-old IVF/ICSI offspring, while growth in childhood was negatively associated with endothelial function.

WHAT IS KNOWN ALREADY

Offspring of pregnancies conceived after ART are at risk for later cardiometabolic risk factors. It is well established that early growth is related to numerous later cardiometabolic risk factors such as high blood pressure. This concept is known as the Developmental Origin of Health and Disease theory.

STUDY DESIGN SIZE DURATION

The relation between early growth and later cardiometabolic risk profile was studied in the MEDIUM-KIDS study, a prospective observational cohort study in children born after an IVF/ICSI treatment. In 131 children (48.1% males) at the average age of 9.4 years, cardiometabolic outcomes were assessed and growth data from birth until age 9 years were collected from child welfare centers.

PARTICIPANTS/MATERIALS SETTINGS METHODS

The following cardiometabolic outcomes were assessed: blood pressure, skinfolds, lipid spectrum, hair cortisone and glucose and insulin levels. Data on maximum skin perfusion after transdermal delivery of acetylcholine as a measure of endothelial function were collected.Growth charts were obtained electronically from child welfare centers, which offer free consultations and vaccinations to all Dutch children. At these centers, height and weight are recorded at predefined ages. Growth was defined as z-score difference in weight between two time points. Multivariable linear regression analysis was used to model the relation between growth and cardiometabolic outcomes. The following growth windows were -studied simultaneously in each model: 0-1 month, 1-3 months, 3-6 months, 6-11 months, 11-24 months and 2-6 years. The model was adjusted for height growth in all intervals except for 0-1 month.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable linear regression analyses, multiple growth windows were positively associated with blood pressure, for example growth from 2-6 years was significantly related to systolic blood pressure: B = 4.13, P = 0.005. Maximum skin perfusion after acetylcholine was negatively associated with height-adjusted weight gain from 2 to 6 years: B = -0.09 (log scale), P = 0.03. Several growth windows (weight 1-3 months, 3-6 months, 6-11 months, 11-24 months, 2-6 years) were positively linked with total adiposity. Lipids, glucose tolerance indices and cortisone were not related to growth.

LIMITATIONS REASONS FOR CAUTION

This study is of modest size and of observational nature, and we did not include a control group. Therefore, we cannot assess whether the observed associations are causal. It is also not possible to analyze if our observations are specific for, or exacerbated in, the ART population. Ideally, a control group of naturally conceived siblings of IVF/ICSI children should simultaneously be studied to address this limitation and to assess the impact of the ART procedure without the influence of parental (subfertility) characteristics.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study contribute to our understanding of the reported increased risk for hypertension in ART offspring. We speculate that early, accelerated growth may be involved in the reported increased risk for hypertension in ART offspring, with endothelial dysfunction as a possible underlying mechanism. However, additional research into the mechanisms involved is required.

STUDY FUNDING/COMPETING INTERESTS

The study was financially supported by the March of Dimes, grant number #6-FY13-153. The sponsor of the study had no role in study design, data collection, data analysis, data interpretation or writing of the paper. The authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

NTR4220.

Cardiometabolic evaluation of small for gestational age children: protective effect of breast milk

Introduction

Introduction: human growth is the result of an interaction between genetic, hormonal, nutritional, and environmental factors. It is not yet fully understood what is predominant and decisive in determining an individual's weight and height. Objective: the aim of this study was to evaluate the cardiometabolic profile of exclusively breastfed children born small for gestational age (SGA). Methods: this is a prospective cohort study of children born at term who were classified as SGA, and as appropiate for gestational age (AGA), who were followed up to pre-school age. Anthropometric measures and body composition parameters were obtained. Breastfeeding duration was calculated in days, and achievement of catch up of weight was considered an increase in Z-score ≥ 0.67. The cardiometabolic profile was evaluated in the first month of life and repeated at pre-school age. At pre-school age, fasting blood glucose, insulin, HOMA-IR, and blood pressure were measured. Results: twenty SGA and 12 AGA children were studied. The mean duration of exclusive breastfeeding (EBF) was 180 days in both groups. Of SGA children, 85 % had recovery anthropometric parameters for age within the first six months, with a speed of weight gain significantly higher than the that of AGAs (p < 0.001). SGAs continued to be thinner and smaller than AGAs at pre-school age. There was no diagnosis of overweight or obesity in the studied sample, and no differences were foun between groups in laboratory tests. Conclusion: these findings suggest that EBF may confer protection until pre-school age in children born SGA, who are considered at higher risk for chronic non-communicable diseases.

Metrics of early childhood growth in recent epidemiological research: A scoping review

Metrics to quantify child growth vary across studies of the developmental origins of health and disease. We conducted a scoping review of child growth studies in which length/height, weight or body mass index (BMI) was measured at ≥ 2 time points. From a 10% random sample of eligible studies published between Jan 2010-Jun 2016, and all eligible studies from Oct 2015-June 2016, we classified growth metrics based on author-assigned labels (e.g., 'weight gain') and a 'content signature', a numeric code that summarized the metric's conceptual and statistical properties. Heterogeneity was assessed by the number of unique content signatures, and label-to-content concordance. In 122 studies, we found 40 unique metrics of childhood growth. The most common approach to quantifying growth in length, weight or BMI was the calculation of each child's change in z-score. Label-to-content discordance was common due to distinct content signatures carrying the same label, and because of instances in which the same content signature was assigned multiple different labels. In conclusion, the numerous distinct growth metrics and the lack of specificity in the application of metric labels challenge the integration of data and inferences from studies investigating the determinants or consequences of variations in childhood growth.