Analysis of 'sensitive' periods of fetal and child growth

Smaller subcortical volume relates to greater weight gain in girls with initially healthy weight

OBJECTIVE

Among 3614 youth who were 9 to 12 years old and initially did not have overweight or obesity (12% [n = 385] developed overweight or obesity), we examined the natural progression of weight gain and brain structure development during a 2-year period with a high risk for obesity (e.g., pre- and early adolescence) to determine the following: 1) whether variation in maturational trajectories of the brain regions contributes to weight gain; and/or 2) whether weight gain contributes to altered brain development.

METHODS

Data were gathered from the Adolescent Brain Cognitive Development (ABCD) Study. Linear mixed-effects regression models controlled for puberty, caregiver education, handedness, and intracranial volume (random effects: magnetic resonance scanner [MRI] scanner and participant). Because pubertal development occurs earlier in girls, analyses were stratified by sex.

RESULTS

For girls, but not boys, independent of puberty, greater increases in BMI were driven by smaller volumes over time in the bilateral accumbens, amygdala, hippocampus, and thalamus, right caudate and ventral diencephalon, and left pallidum (all p < 0.05).

CONCLUSIONS

The results suggest a potential phenotype for identifying obesity risk because underlying differences among regions involved in food intake were related to greater weight gain in girls, but not in boys. Importantly, 2 years of weight gain may not be sufficient to alter brain development, highlighting early puberty as a critical time to prevent negative neurological outcomes.

Determinants of Anishinabeck infant and early childhood growth trajectories in Northwestern Ontario, Canada: a cohort study

BACKGROUND

The Developmental Origins of Health and Disease (DOHaD) paradigm emphasizes the significance of early life factors for the prevention of chronic health conditions, like type 2 diabetes (T2DM) and obesity, which disproportionately affect First Nations communities in Canada. Despite increasing DOHaD research related to maternal health during pregnancy, early childhood growth patterns, and infant feeding practices with many populations, data from First Nations communities in Canada are limited. In partnership with Sandy Lake First Nation, the aims of this project were to characterize birthweights and growth patterns of First Nations infants/children over the first 6 years of life and to study the impact of maternal and infant social and behavioral factors on birthweight and growth trajectories.

METHODS

We recruited 194 families through community announcements and clinic visits. Infant/child length/height and weight were measured at 1 and 2 weeks; 1, 2, 6, 12, and 18 months; and 2, 3, 4, 5 and 6 years. Maternal and infant/child questionnaires captured data about health, nutrition, and social support. Weight-for-Age z-score (WAZ), Height-for-Age z-score (HAZ), and BMI-for-Age z-score (BAZ) were calculated using WHO reference standards and trajectories were analyzed using generalized additive models. Generalized estimating equations and logistic regression were used to determine associations between exposures and outcomes.

RESULTS

WAZ and BAZ were above the WHO mean and increased with age until age 6 years. Generalized estimating equations indicated that WAZ was positively associated with age (0.152; 95% CI 0.014, 0.29), HAZ was positively associated with birthweight (0.155; 95% CI 0.035, 0.275), and BAZ was positively associated with caregiver's BMI (0.049; 95% CI 0.004, 0.090). There was an increased odds of rapid weight gain (RWG) with exposure to gestational diabetes (OR: 7.47, 95% CI 1.68, 46.22). Almost 70% of parents initiated breastfeeding, and breastfeeding initiation was modestly associated with lower WAZ (-0.18; 95% CI -0.64, 0.28) and BAZ (-0.23; 95% CI -0.79, 0.34).

CONCLUSIONS

This work highlights early life factors that may contribute to T2DM etiology and can be used to support community and Indigenous-led prevention strategies.

Growth Velocities Across Distinct Early Life Windows and Child Cognition: Insights from a Contemporary US Cohort

OBJECTIVE

To evaluate the relative importance of overall and period-specific postnatal growth and their interaction with fetal growth on cognition in a generally well-nourished population.

STUDY DESIGN

We included 1052 children from Project Viva, a prospective cohort in Boston, Massachusetts. Using linear spline mixed-effects models, we modeled length/height and body mass index (BMI) trajectories from birth to 7 years and estimated standardized overall (0-7 years) and period-specific growth velocities ie, early infancy (0-4 months), late infancy (4-15 months), toddlerhood (15-37 months), and early childhood (37-84 months). We investigated associations of growth velocities as well as their interactions with birthweight-for-gestational age on mid-childhood (mean age: 7.9 years) IQ, visual memory and learning, and visual motor ability.

RESULTS

Greater overall height velocity was associated with modestly higher design memory score, (adjusted β [95% CI] 0.19 [-0.01,0.38] P = .057])points per SD increase but lower verbal IQ (-0.88 [-1.76,0.00] P = .051). Greater early infancy height velocity was associated with higher visual motor score (1.92 [0.67,3.18]). Greater overall BMI velocity was associated with lower verbal IQ (-0.71 [-1.52,0.11] P = .090). Greater late infancy BMI velocity was associated with lower verbal IQ (-1.21 [-2.07,-0.34]), design memory score (-0.22 [-0.42,-0.03)], but higher picture memory score (0.22 [0.01,0.43]). Greater early infancy height velocity (-1.5 SD vs 1.5 SD) was associated with higher nonverbal IQ (margins [95% CI] 102.6 [98.9106.3] vs 108.2 [104.9111.6]) among small-for-gestational age infants (P-interaction = 0.04).

CONCLUSIONS

Among generally well-nourished children, there might not be clear cognitive gains with faster linear growth except for those with lower birthweight-for-gestational age, revealing the potential importance of early infancy compensatory growth.

Neighborhood Opportunity and Vulnerability and Incident Asthma Among Children

Background

The extent to which physical and social attributes of neighborhoods play a role in childhood asthma remains understudied.

Objective

To examine associations of neighborhood-level opportunity and social vulnerability measures with childhood asthma incidence.

Design, Setting, and Participants

This cohort study used data from children in 46 cohorts participating in the Environmental Influences on Child Health Outcomes (ECHO) Program between January 1, 1995, and August 31, 2022. Participant inclusion required at least 1 geocoded residential address from birth and parent or caregiver report of a physician's diagnosis of asthma. Participants were followed up to the date of asthma diagnosis, date of last visit or loss to follow-up, or age 20 years.

Exposures

Census tract-level Child Opportunity Index (COI) and Social Vulnerability Index (SVI) at birth, infancy, or early childhood, grouped into very low (<20th percentile), low (20th to <40th percentile), moderate (40th to <60th percentile), high (60th to <80th percentile), or very high (≥80th percentile) COI or SVI.

Main Outcomes and Measures

The main outcome was parent or caregiver report of a physician's diagnosis of childhood asthma (yes or no). Poisson regression models estimated asthma incidence rate ratios (IRRs) associated with COI and SVI scores at each life stage.

Results

The study included 10 516 children (median age at follow-up, 9.1 years [IQR, 7.0-11.6 years]; 52.2% male), of whom 20.6% lived in neighborhoods with very high COI and very low SVI. The overall asthma incidence rate was 23.3 cases per 1000 child-years (median age at asthma diagnosis, 6.6 years [IQR, 4.1-9.9 years]). High and very high (vs very low) COI at birth, infancy, or early childhood were associated with lower subsequent asthma incidence independent of sociodemographic characteristics, parental asthma history, and parity. For example, compared with very low COI, the adjusted IRR for asthma was 0.87 (95% CI, 0.75-1.00) for high COI at birth and 0.83 (95% CI, 0.71-0.98) for very high COI at birth. These associations appeared to be attributable to the health and environmental and the social and economic domains of the COI. The SVI during early life was not significantly associated with asthma incidence. For example, compared with a very high SVI, the adjusted IRR for asthma was 0.88 (95% CI, 0.75-1.02) for low SVI at birth and 0.89 (95% CI, 0.76-1.03) for very low SVI at birth.

Conclusions

In this cohort study, high and very high neighborhood opportunity during early life compared with very low neighborhood opportunity were associated with lower childhood asthma incidence. These findings suggest the need for future studies examining whether investing in health and environmental or social and economic resources in early life would promote health equity in pediatric asthma.

Associations between life-course household wealth mobility and adolescent physical growth, cognitive development and emotional and behavioral problems: A birth cohort in rural western China

Background

Parental household wealth has been shown to be associated with offspring health conditions, while inconsistent associations were reported among generally healthy population especially in low- and middle- income countries (LMICs). Whether the household wealth upward mobility in LMICs would confer benefits to child health remains unknown.

Methods

We conducted a prospective birth cohort of children born to mothers who participated in a randomized trial of antenatal micronutrient supplementation in rural western China. Household wealth were repeatedly assessed at pregnancy, mid-childhood and early adolescence using principal component analysis for household assets and dwelling characteristics. We used conditional gains and group-based trajectory modeling to assess the quantitative changes between two single-time points and relative mobility of household wealth over life-course, respectively. We performed generalized linear regressions to examine the associations of household wealth mobility indicators with adolescent height- (HAZ) and body mass index-for-age and sex z score (BAZ), scores of full-scale intelligent quotient (FSIQ) and emotional and behavioral problems.

Results

A total of 1,188 adolescents were followed, among them 59.9% were male with a mean (SD) age of 11.7 (0.9) years old. Per SD conditional increase of household wealth z score from pregnancy to mid-childhood was associated with 0.11 (95% CI 0.04, 0.17) SD higher HAZ and 1.41 (95% CI 0.68, 2.13) points higher FSIQ at early adolescence. Adolescents from the household wealth Upward trajectory had a 0.25 (95% CI 0.03, 0.47) SD higher HAZ and 4.98 (95% CI 2.59, 7.38) points higher FSIQ than those in the Consistently low subgroup.

Conclusion

Household wealth upward mobility particularly during early life has benefits on adolescent HAZ and cognitive development, which argues for government policies to implement social welfare programs to mitigate or reduce the consequences of early-life deprivations. Given the importance of household wealth in child health, it is recommended that socioeconomic circumstances should be routinely documented in the healthcare record in LMICs.

Longitudinal assessment of brain structure and behaviour in youth with rapid weight gain: Potential contributing causes and consequences

OBJECTIVE

Independent of weight status, rapid weight gain has been associated with underlying brain structure variation in regions associated with food intake and impulsivity among pre-adolescents. Yet, we lack clarity on how developmental maturation coincides with rapid weight gain and weight stability.

METHODS

We identified brain predictors of 2-year rapid weight gain and its longitudinal effects on brain structure and impulsivity in the Adolescent Brain Cognitive DevelopmentSM Study®. Youth were categorized as Healthy Weight/Weight Stable (WSHW , n = 527) or Weight Gainers (WG, n = 221, >38lbs); 63% of the WG group were healthy weight at 9-to-10-years-old.

RESULTS

A fivefold cross-validated logistic elastic-net regression revealed that rapid weight gain was associated with structural variation amongst 39 brain features at 9-to-10-years-old in regions involved with executive functioning, appetitive control and reward sensitivity. Two years later, WG youth showed differences in change over time in several of these regions and performed worse on measures of impulsivity.

CONCLUSIONS

These findings suggest that brain structure in pre-adolescence may predispose some to rapid weight gain and that weight gain itself may alter maturational brain change in regions important for food intake and impulsivity. Behavioural interventions that target inhibitory control may improve trajectories of brain maturation and facilitate healthier behaviours.

Associations of Neighborhood Opportunity and Social Vulnerability With Trajectories of Childhood Body Mass Index and Obesity Among US Children

Importance

Physical and social neighborhood attributes may have implications for children's growth and development patterns. The extent to which these attributes are associated with body mass index (BMI) trajectories and obesity risk from childhood to adolescence remains understudied.

Objective

To examine associations of neighborhood-level measures of opportunity and social vulnerability with trajectories of BMI and obesity risk from birth to adolescence.

Design, Setting, and Participants

This cohort study used data from 54 cohorts (20 677 children) participating in the Environmental Influences on Child Health Outcomes (ECHO) program from January 1, 1995, to January 1, 2022. Participant inclusion required at least 1 geocoded residential address and anthropometric measure (taken at the same time or after the address date) from birth through adolescence. Data were analyzed from February 1 to June 30, 2022.

Exposures

Census tract-level Child Opportunity Index (COI) and Social Vulnerability Index (SVI) linked to geocoded residential addresses at birth and in infancy (age range, 0.5-1.5 years), early childhood (age range, 2.0-4.8 years), and mid-childhood (age range, 5.0-9.8 years).

Main Outcomes and Measures

BMI (calculated as weight in kilograms divided by length [if aged <2 years] or height in meters squared) and obesity (age- and sex-specific BMI ≥95th percentile). Based on nationwide distributions of the COI and SVI, Census tract rankings were grouped into 5 categories: very low (<20th percentile), low (20th percentile to <40th percentile), moderate (40th percentile to <60th percentile), high (60th percentile to <80th percentile), or very high (≥80th percentile) opportunity (COI) or vulnerability (SVI).

Results

Among 20 677 children, 10 747 (52.0%) were male; 12 463 of 20 105 (62.0%) were White, and 16 036 of 20 333 (78.9%) were non-Hispanic. (Some data for race and ethnicity were missing.) Overall, 29.9% of children in the ECHO program resided in areas with the most advantageous characteristics. For example, at birth, 26.7% of children lived in areas with very high COI, and 25.3% lived in areas with very low SVI; in mid-childhood, 30.6% lived in areas with very high COI and 28.4% lived in areas with very low SVI. Linear mixed-effects models revealed that at every life stage, children who resided in areas with higher COI (vs very low COI) had lower mean BMI trajectories and lower risk of obesity from childhood to adolescence, independent of family sociodemographic and prenatal characteristics. For example, among children with obesity at age 10 years, the risk ratio was 0.21 (95% CI, 0.12-0.34) for very high COI at birth, 0.31 (95% CI, 0.20-0.51) for high COI at birth, 0.46 (95% CI, 0.28-0.74) for moderate COI at birth, and 0.53 (95% CI, 0.32-0.86) for low COI at birth. Similar patterns of findings were observed for children who resided in areas with lower SVI (vs very high SVI). For example, among children with obesity at age 10 years, the risk ratio was 0.17 (95% CI, 0.10-0.30) for very low SVI at birth, 0.20 (95% CI, 0.11-0.35) for low SVI at birth, 0.42 (95% CI, 0.24-0.75) for moderate SVI at birth, and 0.43 (95% CI, 0.24-0.76) for high SVI at birth. For both indices, effect estimates for mean BMI difference and obesity risk were larger at an older age of outcome measurement. In addition, exposure to COI or SVI at birth was associated with the most substantial difference in subsequent mean BMI and risk of obesity compared with exposure at later life stages.

Conclusions and Relevance

In this cohort study, residing in higher-opportunity and lower-vulnerability neighborhoods in early life, especially at birth, was associated with a lower mean BMI trajectory and a lower risk of obesity from childhood to adolescence. Future research should clarify whether initiatives or policies that alter specific components of neighborhood environment would be beneficial in preventing excess weight in children.

Head circumference trajectories during the first two years of life and cognitive development, emotional, and behavior problems in adolescence: a cohort study

The associations of early-life head circumference (HC) with child neurodevelopmental and mental health among generally healthy population remain unclear. We aimed to examine the associations of early-life HC trajectories with cognitive development and emotional and behavioral problems in adolescence and to identify the HC growth-sensitive period. We conducted a prospective, community-based birth cohort study in rural western China, and 745 adolescents aged 10-14 years were followed between June and December 2016. We assessed their HC eight times during the first 2 years of life and their adolescent cognitive, emotional, and behavioral outcomes using the Wechsler Intelligence Scale for Children-IV and Youth Self-Report-2001, respectively. We applied group-based trajectory modeling to identify the HC trajectories and conditional growth to derive the HC growth-sensitive periods. We identified five distinct HC trajectories characterized as Start below average-then decrease (7.8% of the sample), Start below average-then increase (6.8%), Start average-then decrease (33%), Consistently average (38%), and Consistently above average (14%). Infants in the trajectory of consistently above average had higher cognitive scores in adolescence compared to those from suboptimal trajectories, with adjusted mean differences ranging from 2.84 to 8.99 points. The conditional gains showed that the HC growth-sensitive period was between 0 and 18 months for child cognition. We found null associations between HC measures and adolescent emotional and behavioral problem scores.

CONCLUSION

Early-life HC trajectories were associated with adolescent cognitive development. HC may serve as an inexpensive screening tool to monitor child development at risk during the first 18 months, particularly in resource-limited settings.

WHAT IS KNOWN

• Postnatal head circumference (HC) has been shown to be associated with cognitive development in infants who were born premature and/or fetal growth restriction, while inconsistent associations were reported among generally healthy populations, especially in low- and middle- income countries, challenging its utility in public health practices.

WHAT IS NEW

• Adolescents in the HC growth trajectory of consistently above average had higher cognitive scores compared to those with other suboptimal trajectories, while null findings were observed for adolescent emotional and behavioral health. • HC may serve as an inexpensive screening tool to monitor child development at risk during the first 18 months of life, particularly in resource-limited settings.

Applications of conceptual models from lifecourse epidemiology in ecology and evolutionary biology

In ecology and evolutionary biology (EEB), the study of developmental plasticity seeks to understand ontogenetic processes underlying the phenotypes upon which natural selection acts. A central challenge to this inquiry is ascertaining a causal effect of the exposure on the manifestation of later-life phenotype due to the time elapsed between the two events. The exposure is a potential cause of the outcome-i.e. an environmental stimulus or experience. The later phenotype might be a behaviour, physiological condition, morphology or life-history trait. The latency period between the exposure and outcome complicates causal inference due to the inevitable occurrence of additional events that may affect the relationship of interest. Here, we describe six distinct but non-mutually exclusive conceptual models from the field of lifecourse epidemiology and discuss their applications to EEB research. The models include Critical Period with No Later Modifiers, Critical Period with Later Modifiers, Accumulation of Risk with Independent Risk Exposures, Accumulation of Risk with Risk Clustering, Accumulation of Risk with Chains of Risk and Accumulation of Risk with Trigger Effect. These models, which have been widely used to test causal hypotheses regarding the early origins of adult-onset disease in humans, are directly relevant to research on developmental plasticity in EEB.

Associations of midchildhood to early adolescence central adiposity gain with cardiometabolic health in early adolescence

OBJECTIVE

This study examined the associations of central adiposity gain from midchildhood to early adolescence with cardiometabolic health markers in early adolescence.

METHODS

A total of 620 participants were studied in Project Viva. In midchildhood (mean age = 7.8 years) and early adolescence (12.9 years), waist circumference and dual-energy x-ray absorptiometry-measured visceral adipose tissue, subcutaneous abdominal adipose tissue, and trunk fat were obtained. Central adiposity gain was calculated as change per year between visits. Cardiometabolic health markers, including blood pressure, lipids, markers of insulin resistance, inflammation, and adipokines, were collected in early adolescence.

RESULTS

Greater waist circumference gain was associated with higher log triglycerides (β 0.07 mg/dL; 95% CI: 0.02-0.13), log alanine aminotransferase (0.07 U/L; 95% CI: 0.03-0.12), log high-sensitivity C-reactive protein (0.43 mg/L; 95% CI: 0.28-0.58), and other cardiometabolic markers in early adolescence. Directly measured central adiposity gains were associated with higher systolic blood pressure z score in early adolescence (visceral adipose tissue [0.13 SD units; 95% CI: 0.04-0.23], subcutaneous abdominal adipose tissue [0.18 SD units; 95% CI: 0.04-0.31], and trunk fat [0.21 SD units; 95% CI: 0.06-0.36]). These associations were independent of baseline and change in total adiposity from midchildhood to early adolescence.

CONCLUSIONS

Monitoring central adiposity gain may enable identification and intervention in children vulnerable to developing cardiometabolic health risks.

Prenatal exposure to endocrine disrupting chemicals is associated with altered DNA methylation in cord blood

Prenatal exposure to endocrine disrupting chemicals can interfere with development, and has been associated with social-cognitive functioning and adverse health outcomes later in life. Exposure-associated changes of DNA methylation (DNAm) patterns have been suggested as a possible mediator of this relationship. This study investigated whether prenatal low-dose exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) is associated with altered DNAm patterns across the genome in a Western urban-industrial population. In 142 mother-infant pairs from the Duisburg Birth Cohort Study, PCBs and PCDD/Fs levels were quantified from maternal blood during late pregnancy and associated with DNAm levels in cord blood using the Illumina EPIC beadchip. The epigenome-wide association studies (EWAS) identified 32 significantly differentially methylated positions (DMPs) and eight differentially methylated regions (DMRs) associated with six congeners of PCB and PCDD in females or males (FDRs < 0.05). DMPs and DMRs mapped to genes involved in neurodevelopment, gene regulation, and immune functioning. Weighted gene correlation network analysis (WGCNA) showed 31 co-methylated modules (FDRs < 0.05) associated with one congener of PCDF levels in females. Results of both analytical strategies indicate that prenatal exposure to PCBs and PCDD/Fs is associated with altered DNAm of genes involved in neurodevelopment, gene expression and immune functioning. DNAm and gene expression levels of several of these genes were previously associated with EDC exposure in rodent models. Follow-up studies will clarify whether these epigenetic changes might contribute to the origin for adverse mental and health outcomes.

Physical growth and neurodevelopment during the first year of life: a cohort study of the Japan Environment and Children's Study

BACKGROUND

The association between a slower physical growth and poorer neurodevelopment has been established in infants born preterm or small for gestational age. However, this association is inconsistent in term-born infants, and detailed investigations in infancy, when intervention is most beneficial for improving outcomes, are lacking. We therefore examined this association separately by sex during the first year of life in term-born infants.

METHODS

Using data collected until children reached 12 months old in an ongoing prospective cohort of the Japan Environment and Children's Study, we analyzed 44,264 boys and 42,541 girls with singleton term-birth. The exposure variables were conditional variables that disentangle linear growth from weight gain relative to linear growth, calculated from the length and weight at birth and 4, 7 and 10 months old. Neurodevelopmental delay was identified using the Japanese-translated version of Ages & Stages Questionnaires, third edition.

RESULTS

A reduced risk of neurodevelopmental delay at 6 months old was observed in children with a higher birth weight (adjusted relative risks [aRRs]: 0.91 and 0.93, 95 % confidence intervals [95 % CIs]: 0.87-0.96 and 0.88-0.98 in boys and girls, respectively) and increased linear growth between 0 and 4 months old (aRRs: 0.85 and 0.87, 95 % CIs: 0.82-0.88 and 0.83-0.91 in boys and girls, respectively). A reduced risk at 12 months was found in children with an increased linear growth between 0 and 4 months (aRRs: 0.92 and 0.90, 95 % CIs: 0.87-0.98 and 0.84-0.96 in boys and girls, respectively), boys with an increased relative weight gain between 0 and 4 months (aRR: 0.90, 95 % CI: 0.84-0.97), and girls with a higher birth weight (aRR: 0.89, 95 % CI: 0.83-0.96).

CONCLUSIONS

These results suggest that a slow physical growth by four months old may be a predictor of neurodevelopmental delay during infancy.

Association of Early Antibiotic Exposure With Childhood Body Mass Index Trajectory Milestones

IMPORTANCE

Past studies have showed associations between antibiotic exposure and child weight outcomes. Few, however, have documented alterations to body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) trajectory milestone patterns during childhood after early-life antibiotic exposure.

OBJECTIVE

To examine the association of antibiotic use during the first 48 months of life with BMI trajectory milestones during childhood in a large cohort of children.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used electronic health record data from 26 institutions participating in the National Patient-Centered Clinical Research Network from January 1, 2009, to December 31, 2016. Participant inclusion required at least 1 valid set of same-day height and weight measurements at each of the following age periods: 0 to 5, 6 to 11, 12 to 23, 24 to 59, and 60 to 131 months (183 444 children). Data were analyzed from June 1, 2019, to June 30, 2020.

EXPOSURES

Antibiotic use at 0 to 5, 6 to 11, 12 to 23, 24 to 35, and 36 to 47 months of age.

MAIN OUTCOMES AND MEASURES

Age and magnitude of BMI peak and BMI rebound.

RESULTS

Of 183 444 children in the study (mean age, 3.3 years [range, 0-10.9 years]; 95 228 [51.9%] were boys; 80 043 [43.6%] were White individuals), 78.1% received any antibiotic, 51.0% had at least 1 episode of broad-spectrum antibiotic exposure, and 65.0% had at least 1 episode of narrow-spectrum antibiotic exposure at any time before 48 months of age. Exposure to any antibiotics at 0 to 5 months of age (vs no exposure) was associated with later age (β coefficient, 0.05 months [95% CI, 0.02-0.08 months]) and higher BMI (β coefficient, 0.09 [95% CI, 0.07-0.11]) at peak. Exposure to any antibiotics at 0 to 47 months of age (vs no exposure) was associated with an earlier age (-0.60 months [95% CI, -0.81 to -0.39 months]) and higher BMI at rebound (β coefficient, 0.02 [95% CI, 0.01-0.03]). These associations were strongest for children with at least 4 episodes of antibiotic exposure. Effect estimates for associations with age at BMI rebound were larger for those exposed to antibiotics at 24 to 35 months of age (β coefficient, -0.63 [95% CI, -0.83 to -0.43] months) or 36 to 47 (β coefficient, -0.52 [95% CI, -0.72 to -0.31] months) than for those exposed at 0 to 5 months of age (β coefficient, 0.26 [95% CI, 0.01-0.51] months) or 6 to 11 (β coefficient, 0.00 [95% CI, -0.20 to 0.20] months).

CONCLUSIONS AND RELEVANCE

In this cohort study, antibiotic exposure was associated with statistically significant, but small, differences in BMI trajectory milestones in infancy and early childhood. The small risk of an altered BMI trajectory milestone pattern associated with early-life antibiotic exposure is unlikely to be a key factor during prescription decisions for children.

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.

Body Composition Measurements from Birth through 5 Years: Challenges, Gaps, and Existing & Emerging Technologies-A National Institutes of Health workshop

Body composition estimates are widely used in clinical research and field studies as measures of energy-nutrient balance, functionality and health. Despite their broad relevance and multiple applications, important gaps remain in techniques available for accurately and precisely quantifying body composition in infants and children from birth through 5 years. Identifying these gaps and highlighting research needs in this age group were the topics of a National Institutes of Health workshop held in Bethesda, MD, USA, 30-31 May 2019. Experts reviewed available methods (multicompartment models, air-displacement plethysmography, dual-energy X-ray absorptiometry, weight-length and height indices, bioimpedance analysis, anthropometry-skinfold techniques, quantitative magnetic resonance, optical imaging, omics and D3-creatine dilution), their limitations in this age range and high priority research needs. A summary of their individual and collective workshop deliberations is provided in this report.

Associations of types of green space across the life-course with blood pressure and body mass index

Green space has been associated with better health and well-being. However, most studies have been cross-sectional with limited long-term exposure data. Further, research is limited in what type of green space is beneficial for health. We conducted a longitudinal study to assess sensitive periods (birth, childhood or adulthood) of exposure to different types of green space in association with adult blood pressure and body mass index (BMI). Using longitudinal data from the New England Family Study (1960-2000) and multilevel regression analysis, we examined associations between time-varying markers of residential exposure to green space, and adult BMI, systolic (SBP) and diastolic blood pressure (DBP) (N = 517). We created three exposure metrics: distance, average area, and green space count in the neighborhood throughout the life-course. In adjusted models, living one mile farther away from a green space at birth was associated with a 5.6 mmHg higher adult SBP (95%CI: 0.7, 10.5), and 3.5 mmHg higher DBP (95%CI: 0.3, 6.8). One more green space in the neighborhood at birth was also associated with lower DBP (-0.2 mmHg, 95%CI: -0.4, -0.02) in adulthood. Finally, average area of green space was not associated with SBP, DBP nor BMI. Analysis by type of green space suggested that parks may be more relevant than playgrounds, cemeteries or golf courses. Our study suggests that the perinatal period may be a critical time-period where living closer to green spaces may lower hypertension risk in adulthood, but not obesity.

Growth During Infancy and Early Childhood and Its Association With Metabolic Risk Biomarkers at 11.5 Years of Age

The evidence that fetal life and early infancy are "critical" or "sensitive" ages for later development of cardiometabolic disease is based on flawed methods for comparing different age periods. Moreover, most previous studies have limited their focus to weight gain, rather than growth in length/height or body mass index (weight (kg)/height (m)2). We undertook a secondary analysis of data from the Promotion of Breastfeeding Intervention Trial (1996-2010), a birth cohort study nested within a large cluster-randomized trial in the Republic of Belarus, that had repeated measurements of weight and length/height taken from birth to 11.5 years of age. We used mixed-effects linear models to analyze associations of changes in standardized weight, length/height, and body mass index during 5 age periods (conception to birth, birth to age 3 months, ages 3-12 months, ages 12 months-6.5 years, and ages 6.5-11.5 years) with fasting glucose, insulin, insulin resistance, β-cell function, and adiponectin at age 11.5 years. We observed strong associations between the metabolic markers and all 3 growth measures, with the largest magnitudes being observed during the latest age period (ages 6.5-11.5 years) and negligible associations during gestation and the first year of life. Later age periods appear more "sensitive" than earlier periods to the adverse metabolic association with rapid growth in childhood.

Epitopes as characterized by antibody-verified eplet mismatches determine risk of kidney transplant loss

To optimize strategies that mitigate the risk of graft loss associated with HLA incompatibility, we evaluated whether sequence defined HLA targets (eplets) that result in donor-specific antibodies are associated with transplant outcomes. To define this, we fit multivariable Cox proportional hazard models in a cohort of 118 382 United States first kidney transplant recipients to assess risk of death-censored graft failure by increments of ten antibody-verified eplet mismatches. To verify robustness of our findings, we conducted sensitivity analysis in this United States cohort and assessed the role of antibody-verified eplet mismatches as autonomous predictors of transplant glomerulopathy in an independent Canadian cohort. Antibody-verified eplet mismatches were found to be independent predictors of death-censored graft failure with hazard ratios of 1.231 [95% confidence interval 1.195, 1. 268], 1.268 [1.231, 1.305] and 1.411 [1.331, 1.495] for Class I (HLA-A, B, and C), -DRB1 and -DQB1 loci, respectively. To address linkage disequilibrium between HLA-DRB1 and -DQB1, we fit models in a subcohort without HLA-DQB1 eplet mismatches and found hazard ratios for death-censored graft failure of 1.384 [1.293, 1.480] for each additional antibody-verified HLA-DRB1 eplet mismatch. In a subcohort without HLA-DRB1 mismatches, the hazard ratio was 1.384 [1.072, 1.791] for each additional HLA-DQB1 mismatch. In the Canadian cohort, antibody-verified eplet mismatches were independent predictors of transplant glomerulopathy with hazard ratios of 5.511 [1.442, 21.080] for HLA-DRB1 and 3.640 [1.574, 8.416] for -DRB1/3/4/5. Thus, donor-recipient matching for specific HLA eplets appears to be a feasible and clinically justifiable strategy to mitigate risk of graft loss.

Association of accelerated body mass index gain with repeated measures of blood pressure in early childhood

Background/objectives

We examined the association for rates of age- and sex-standardized body mass index (zBMI) gain between 0–3, 3–18, and 18–36 months with BP in children at 36–72 months of age.

Methods

We collected repeated measures of zBMI and BP in 2502 children. zBMI was calculated using the World Health Organization standards. Each child’s zBMI at birth and rates of zBMI gain in each period from birth to 36 months were estimated using linear spline multilevel models. Generalized estimating equations were used to determine whether zBMI at birth and zBMI gain between 0–3, 3–18, and 18–36 months were each associated with repeated measures of BP at 36–72 months of age. We sequentially conditioned on zBMI at birth and zBMI gain in each period prior to each period tested, as covariates, and adjusted for important socio-demographic, familial, and study design covariates. We examined whether these associations were modified by birthweight or maternal obesity, by including interaction terms.

Results

After adjusting for all covariates and conditioning on prior zBMI gains, a 1 standard deviation unit faster rate of zBMI gain during 0–3 months, (β = 0.59 mmHg; 95% CI 0.31, 0.86) and 3–18 months (β = 0.74 mmHg; 95% CI 0.46, 1.03) were each associated with higher systolic BP at 36–72 months. No significant associations were observed, however, for zBMI at birth or zBMI gain in the 18–36 month growth period. zBMI gains from 0–3 and 3–18 months were also associated with diastolic BP. Birthweight significantly modified the relationship during the 3–18 month period (p = 0.02), with the low birthweight group exhibiting the strongest association for faster rate of zBMI gain with higher systolic BP (β = 1.31 mmHg; 95% CI 0.14, 2.48).

Conclusions

Given that long-term exposure to small elevations in BP are associated with subclinical cardiovascular disease, promoting interventions targeting healthy growth in infancy may be important.

Patterns of body mass index milestones in early life and cardiometabolic risk in early adolescence

BACKGROUND

Few studies have examined the independent and combined relationships of body mass index (BMI) peak and rebound with adiposity, insulin resistance and metabolic risk later in life. We used data from Project Viva, a well-characterized birth cohort from Boston with repeated measures of BMI, to help fill this gap.

METHODS

Among 1681 children with BMI data from birth to mid childhood, we fitted individual BMI trajectories using mixed-effects models with natural cubic splines and estimated age, and magnitude of BMI, at peak (in infancy) and rebound (in early childhood). We obtained cardiometabolic measures of the children in early adolescence (median 12.9 years) and analysed their associations with the BMI parameters.

RESULTS

After adjusting for potential confounders, age and magnitude at infancy BMI peak were associated with greater adolescent adiposity, and earlier adiposity rebound was strongly associated with greater adiposity, insulin resistance and metabolic risk score independently of BMI peak. Children with a normal timing of BMI peak plus early rebound had an adverse cardiometabolic profile, characterized by higher fat mass index {β 2.2 kg/m2 [95% confidence interval (CI) 1.6, 2.9]}, trunk fat mass index [1.1 kg/m2 (0.8, 1.5)], insulin resistance [0.2 units (0.04, 0.4)] and metabolic risk score [0.4 units (0.2, 0.5)] compared with children with a normal BMI peak and a normal rebound pattern. Children without a BMI peak (no decline in BMI after the rise in infancy) also had adverse adolescent metabolic profiles.

CONCLUSIONS

Early age at BMI rebound is a strong risk factor for cardiometabolic risk, independent of BMI peak. Children with a normal peak-early rebound pattern, or without any BMI decline following infancy, are at greatest risk of adverse cardiometabolic profile in adolescence. Routine monitoring of BMI may help to identify children who are at greatest risk of developing an adverse cardiometabolic profile in later life and who may be targeted for preventive interventions.