How pre- and postnatal risk factors modify the effect of rapid weight gain in infancy and early childhood on subsequent fat mass development: results from the Multicenter Allergy Study 90

Latent classes of anthropometric growth in early childhood using uni- and multivariate approaches in a South African birth cohort

BACKGROUND

Defining growth patterns during childhood is key to identifying future health risk and vulnerable periods for potential interventions. The aim of this study was to identify growth profiles in children from birth to five years in a South African birth cohort, the Drakenstein Child Health Study (DCHS) using a Latent Class Mixed Modelling (LCMM) approach.

METHODS

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

RESULTS

Four classes of growth within standardized height (n1=516, n2=112, n3=187, n4=321) and standardized weight (n1=263, n2=150, n3=584, n4=142), three latent growth classes within Body Mass Index (BMI) (n1=481, n2=485, n3=149) and Weight for length/height (WFH) (n1=321, n2=710, n3=84) and five latent growth classes within the multivariate response of standardized height and standardized weight (n1=318, n2=205, n3=75, n4=296, n5=242) were identified, each with distinct trajectories over childhood. A strong association (much greater or lesser than expected proportions (an increase by 25% in some cases), when compared to the proportion of abnormal growth features across the entire cohort) was found between various growth classes and abnormal growth features such as rapid weight gain, stunting, underweight and overweight.

CONCLUSIONS

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

Rapid Growth between 0 and 2 Years Old in Healthy Infants Born at Term and Its Relationship with Later Obesity: A Systematic Review and Meta-Analysis of Evidence

INTRODUCTION

Rapid growth in early childhood has been identified as a possible risk factor for long-term adiposity. However, there is a lack of studies quantifying this phenomenon only in healthy, full-term infants with appropriate birth weight for gestational age. This systematic review and meta-analysis aimed to investigate the association of rapid growth in full-term children up to 2 years of age with adiposity up to 18 years of age.

METHODOLOGY

A systematic review of the literature was conducted in PubMed, EMBASE, and Web of Science.

RESULTS

14 studies were included. We were unable to find strong evidence that rapid growth in early childhood is a risk factor for long-term adiposity. Rapid growth in early childhood was associated with taller heights (standardized mean difference: 0.51 (CI: 0.25-0.77)) and higher body mass index (standardized mean difference: 0.50 (CI: 0.25-0.76)) and a higher risk of overweight under 18 years.

CONCLUSION

Rapid growth in early childhood in term infants with appropriate birth weight is associated with higher growth, body mass index, and risk of being overweight up to age 18, but further work is needed to identify the associations between early rapid growth and obesity later in adulthood.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

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

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

Background

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

Methods

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

Results

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

Conclusions

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

Association of Maternal BMI and Rapid Infant Weight Gain With Childhood Body Size and Composition

OBJECTIVES

Maternal prepregnancy BMI (ppBMI) and an infant's rapid weight gain (RWG) are each associated with increased risk for childhood obesity. We hypothesized that ppBMI and RWG interact to further raise childhood obesity risk.

METHODS

Mother-infant dyads (n = 414) from the Healthy Start Study, an observational prebirth cohort, were included. RWG was defined as a weight-for-age z score increase of ≥0.67 from birth to 3 to 7 months. Body composition was measured by air displacement plethysmography at age 4 to 7 years. General linear regression models were fit to characterize associations between ppBMI, RWG, and their interaction with the outcomes of childhood BMI-for-age z score and percent fat mass (%FM).

RESULTS

A total of 18.6% (n = 77) of offspring experienced RWG. Maternal ppBMI and RWG were both positively associated with offspring BMI z score and %FM. RWG amplified the association between ppBMI and BMI z score, especially among females. Females exposed to maternal obesity and RWG had an average BMI at the 94th percentile (1.50 increase in childhood BMI z score) compared with those exposed to normal ppBMI and no RWG (average childhood BMI at the 51st percentile). RWG had a weaker effect on the association between ppBMI and %FM. Adjustment for breastfeeding status or childhood daily caloric intake did not significantly alter findings.

CONCLUSIONS

Rapid infant weight gain interacts with maternal ppBMI to jointly exacerbate risk of childhood obesity. Pediatric providers should monitor infants for RWG, especially in the context of maternal obesity, to reduce future risk of obesity.

Resource dilution in maternal feeding practices after birth of a secondborn

Firstborn children have higher prevalence of obesity than secondborn siblings. The birth of a sibling typically results in resource dilution when mothers begin to divide their time and attention between two children. This mixed-methods analysis applies the family systems process of resource dilution to test the hypothesis that characteristics of the secondborn impact how parents feed the firstborn. Participants (n = 76) were mothers of consecutively born firstborn and secondborn siblings who participated in the INSIGHT trial and an observational cohort. Quantitative analyses involved multilevel models to test if characteristics of secondborns (temperament at 16 weeks, appetite at 28 weeks) were associated with maternal feeding practices of firstborns (structure and control-based feeding) at 1, 2, and 3 years, adjusting for firstborn child characteristics. A purposive subsample (n = 30) of mothers participated in semi-structured interviews to contextualize potential sibling influences on maternal feeding practices during infancy and toddlerhood. Quantitative data showed secondborn temperament and appetite were associated with how mothers fed their firstborn. Qualitative data explained maternal feeding practices in three primary ways: 1) Mothers explained shifting predictable meal and snack routines after birth of the secondborn, but did not perceive sibling characteristics as the source; 2) Family chaos following the secondborn's birth led to "survival mode" in feeding; and 3) Social support was protective against feeding resource dilution. The family systems process of resource dilution is a focus for future research and support for families during key transitions and a direction for efforts to reduce risk for child obesity.

The care of infants with rapid weight gain: Should we be doing more?

Rapid weight gain (RWG) during infancy is a known risk factor for later childhood obesity. It can be measured using a range of definitions across various time periods in the first 2 years of life. In recent years, some early childhood obesity prevention trials have included a focus on preventing RWG during infancy, with modest success. Overall, RWG during infancy remains common, yet little work has examined whether infants with this growth pattern should receive additional care when it is identified in health-care settings. In this viewpoint, we contend that RWG during infancy should be routinely screened for in health-care settings, and when identified, viewed as an opportunity for health-care professionals to instigate non-stigmatising discussions with families about RWG and general healthy practices for their infants. If families wish to engage, we suggest that six topics from early life obesity prevention studies (breastfeeding, formula feeding, complementary feeding, sleep, responsive parenting, and education around growth charts and monitoring) could form the foundations of conversations to help them establish and maintain healthy habits to support their infant's health and well-being and potentially lower the risk of later obesity. However, further work is needed to develop definitive guidelines in this area, and to address other gaps in the literature, such as the current lack of a standardised definition for RWG during infancy and a clear understanding of the time points over which it should be measured.

Determinants of rapid infant weight gain: A pooled analysis of seven cohorts

OBJECTIVE

Rapid weight gain (RWG) in infancy is strongly associated with subsequent obesity risk, but little is known about the factors driving RWG. This study explored the child and maternal factors associated with infant RWG.

METHODS

Data from seven Australian and New Zealand cohorts were used (n = 4542). Infant RWG was defined as a change in weight z-score ≥0.67 from birth to age 1 year. Univariable and multivariable logistic regression assessed the association between child and maternal factors and infant RWG in each cohort. Meta-analysis was conducted to obtain pooled effect sizes.

RESULTS

Multivariable analyses revealed boys were more likely to experience RWG (OR 1.42 95% CI 1.22, 1.66) than girls. Higher birth weight in kg (OR 0.09, 95% CI 0.04, 0.20) and gestational age in weeks (OR 0.69, 95% CI 0.48, 0.98) were associated with lower RWG risk. Children who were breastfed for ≥6 months showed lower RWG risk (OR 0.45, 95% CI 0.38, 0.53). Children of native-born versus overseas-born women appeared to have higher RWG risk (OR 1.37, 95% CI 0.99, 1.90). Maternal smoking during pregnancy increased RWG risk (OR 1.60, 95% CI 1.28, 2.01), whereas children who started solids ≥6 months (OR 0.77, 95% CI 0.63, 0.93) and children with siblings (OR 0.68, 95% CI 0.57, 0.81) showed lower RWG risk in univariable analysis, but these associations were attenuated in multivariable analysis. No association was found for maternal age, education, marital status and pre-pregnancy BMI.

CONCLUSION

Maternal country of birth, smoking status, child sex, birth weight, gestational age, infant feeding and parity were potential determinants of infant RWG.

A mixed methods study of siblings’ roles in maternal feeding practices in early childhood: an application of the learning from experience process

Background

Firstborn children have higher rates of obesity compared to secondborns, perhaps due, in part, to differential feeding practices. Despite the centrality of siblings in family life and potential for influence, almost nothing is known about the role of siblings in parent feeding practices in early childhood.

Methods

Participants (n = 117) were mothers of consecutively born siblings. Firstborns participated in an RCT that compared a responsive parenting intervention designed for primary prevention of obesity against a safety control. Secondborns participated in an observational cohort. Multilevel models tested whether and how firstborn characteristics (temperament, appetite, rapid weight gain) at 16 weeks and 1 year were associated maternal feeding practices of secondborns in infancy at 16 weeks, 28 weeks, and 1 year (food to soothe) and at ages 1, 2, and 3 years (structure-and control-based feeding practices). A purposive subsample (n = 30) of mothers also participated in semi-structured interviews to further illuminate potential sibling influences on maternal feeding practices during infancy and toddlerhood.

Results

Firstborn characteristics did not predict secondborn feeding in infancy (all ps > 0.05). Firstborn negative affect, however, predicted mothers’ less consistent mealtime routines (b (SE) = − 0.27 (0.09); p = 0.005) and more pressure (b (SE) = 0.38 (0.12); p = 0.001). Firstborn appetite predicted mothers’ less frequent use of food to soothe (b (SE) = − 0.16 (0.07); p = 0.02) when secondborns were toddlers. Firstborn surgency, regulation, and rapid weight gain, however, did not predict secondborn feeding practices during toddlerhood (all ps > 0.05). Interviews with mothers revealed three ways that maternal experiences with firstborns informed feeding practices of secondborns: 1) Use of feeding practices with secondborn that worked for the firstborn; 2) Confidence came from firstborn feeding experiences making secondborn feeding less anxiety-provoking; and 3) Additional experiences with firstborn and other factors that contributed to secondborn feeding practices.

Conclusions

Some firstborn characteristics and maternal experiences with firstborns as well as maternal psychosocial factors may have implications for mothers’ feeding practices with secondborns. Together, these mixed methods findings may inform future research and family-based interventions focused on maternal feeding of siblings in early childhood.

INSIGHT responsive parenting educational intervention for firstborns is associated with growth of second-born siblings

OBJECTIVE

The aim of this study was to test whether the Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) responsive parenting (RP) intervention, delivered to parents of firstborn children, is associated with the BMI of first- and second-born siblings during infancy.

METHODS

Participants included 117 firstborn infants enrolled in a randomized controlled trial and their second-born siblings enrolled in an observation-only ancillary study. The RP curriculum for firstborn children included guidance on feeding, sleep, interactive play, and emotion regulation. The control curriculum focused on safety. Anthropometrics were measured in both siblings at ages 3, 16, 28, and 52 weeks. Growth curve models for BMI by child age were fit.

RESULTS

Second-born children were delivered 2.5 (SD 0.9) years after firstborns. Firstborn and second-born children whose parents received the RP intervention with their first child had BMI that was 0.44 kg/m2 (95% CI: -0.82 to 0.06) and 0.36 kg/m2 (95% CI: -0.75 to 0.03) lower than controls, respectively. Linear and quadratic growth rates for BMI for firstborn and second-born cohorts were similar, but second-born children had a greater average BMI at 1 year of age (difference = -0.33 [95% CI: -0.52 to -0.15]).

CONCLUSIONS

A RP educational intervention for obesity prevention delivered to parents of firstborns appears to spill over to second-born siblings.

Protocol of the Snuggle Bug/Acurrucadito Study: a longitudinal study investigating the influences of sleep-wake patterns and gut microbiome development in infancy on rapid weight gain, an early risk factor for obesity

BACKGROUND

Overweight, obesity, and associated comorbidities are a pressing global issue among children of all ages, particularly among low-income populations. Rapid weight gain (RWG) in the first 6 months of infancy contributes to childhood obesity. Suboptimal sleep-wake patterns and gut microbiota (GM) have also been associated with childhood obesity, but little is known about their influences on early infant RWG. Sleep may alter the GM and infant metabolism, and ultimately impact obesity; however, data on the interaction between sleep-wake patterns and GM development on infant growth are scarce. In this study, we aim to investigate associations of infant sleep-wake patterns and GM development with RWG at 6 months and weight gain at 12 months. We also aim to evaluate whether temporal interactions exist between infant sleep-wake patterns and GM, and if these relations influence RWG.

METHODS

The Snuggle Bug/ Acurrucadito study is an observational, longitudinal study investigating whether 24-h, actigraphy-assessed, sleep-wake patterns and GM development are associated with RWG among infants in their first year. Based on the Ecological Model of Growth, we propose a novel conceptual framework to incorporate sleep-wake patterns and the GM as metabolic contributors for RWG in the context of maternal-infant interactions, and familial and socio-physical environments. In total, 192 mother-infant pairs will be recruited, and sleep-wake patterns and GM development assessed at 3 and 8 weeks, and 3, 6, 9, and 12 months postpartum. Covariates including maternal and child characteristics, family and environmental factors, feeding practices and dietary intake of infants and mothers, and stool-derived metabolome and exfoliome data will be assessed. The study will apply machine learning techniques combined with logistic time-varying effect models to capture infant growth and aid in elucidating the dynamic associations between study variables and RWG.

DISCUSSION

Repeated, valid, and objective assessment at clinically and developmentally meaningful intervals will provide robust measures of longitudinal sleep, GM, and growth. Project findings will provide evidence for future interventions to prevent RWG in infancy and subsequent obesity. The work also may spur the development of evidence-based guidelines to address modifiable factors that influence sleep-wake and GM development and prevent childhood obesity.

Learned Experience and Resource Dilution: Conceptualizing Sibling Influences on Parents' Feeding Practices

Studies from diverse cultures report mixed results in the relationship between birth order and risk for obesity. Explanations may thus lie in the postnatal period when growth is shaped by the family environment, including parental feeding practices, which may be affected by siblings. Consistent with a family systems perspective, we describe two processes that may explain birth order effects on parental feeding practices and child outcomes: learned experience and resource dilution. Parents learn from experience when earlier-born children influence their parents’ knowledge, expectations, and behavior toward later-born siblings through their behaviors and characteristics—which can have both positive and negative implications. Resource dilution is a process whereby the birth of each child limits the time, attention and other resources parents have to devote to any one of their children. The goal of this review is to provide a theoretical basis for examining potential sibling influences on parental responsive feeding toward developing recommendations for future research and practice aimed at preventing obesity throughout family systems.

Association Between Fat Mass in Early Life and Later Fat Mass Trajectories

IMPORTANCE

A rapid increase in weight in early life is associated with an increased risk for adiposity and cardiovascular diseases at age 21 years and beyond. However, data on associations of early change in measured fat mass percentage (FM%) with adiposity development are lacking.

OBJECTIVE

To investigate whether a rapid increase in FM% in the first months of life is associated with higher trajectories of body fat mass during the first 2 years of life.

DESIGN, SETTING, AND PARTICIPANTS

A birth cohort consisting of 401 healthy, term-born infants of the Sophia Pluto Cohort Study was analyzed. Participants were born between January 7, 2013, and October 13, 2017. Data were analyzed from February 1, 2020, to May 20, 2020.

INTERVENTIONS

Longitudinal measurements of FM% by air-displacement plethysmography and dual-energy x-ray absorptiometry, and abdominal subcutaneous and visceral fat mass (FM) by ultrasonography in infants at ages 1, 3, 6, 9, 12, 18, and 24 months. A rapid increase in FM% was defined as a change in FM% of greater than 0.67 standard deviation scores (SDS).

MAIN OUTCOMES AND MEASURES

Associations between change in FM% SDS in the first and second 6-month period of life with body composition at age 2 years and whether a rapid increase in FM% SDS during the first 6 months leads to higher body FM and abdominal FM trajectories during the first 2 years of life.

RESULTS

Of the 401 participants, 228 infants (57%) were male. Change in FM% SDS from age 1 to 6 months was positively associated with FM% (β, 0.044; 95% CI, 0.017-0.068), FMI (β, 0.061; 95% CI, 0.032-0.091), and abdominal subcutaneous FM (β, 0.064; 95% CI, 0.036-0.092) at age 2 years, but not with visceral FM. In contrast, no associations were found within the 6- to 12-month period. Infants with a rapid increase in FM% of greater than 0.67 SDS in the first 6 months of life had higher trajectories of FM%, FM index, and subcutaneous FM during the first 2 years of life (all P≤.001), but visceral FM index was not significantly different compared with infants without a rapid increase (P = .12).

CONCLUSIONS AND RELEVANCE

In this study, only the change in FM% in the first 6 months of life was associated with more adiposity at age 2 years. Infants with a rapid increase in FM% had higher trajectories of FM% and FM index during the first 2 years of life. These findings appear to support a critical window for adiposity programming in early life.

Relationship between prenatal and postnatal conditions and accelerated postnatal growth. Impact on the rigidity of the arterial wall and obesity in childhood

Restricted growth in utero and accelerated postnatal growth (APG) in the postnatal period have been associated with the development of overweight, obesity and an increased cardiovascular risk in childhood. The objectives of this study were to evaluate the influence of prenatal and perinatal conditions on APG and to evaluate the influence of this APG on different cardiovascular risk factors such as body mass index (BMI), body fat mass index (FMI), blood pressure (BP) and arterial wall stiffness [carotid to femoral pulse wave velocity (cf-PWV)]. All measurements were performed in 355 children (185 boys and 170 girls; 8-11 years). Data on mother weight before and during pregnancy, gestational age (weeks), birth weight (g) and breastfeeding of children were obtained through interviews with families. Children who presented APG were born of mothers with lower BMIs before pregnancy and who gained less weight during the second trimester of pregnancy. They also have a lower gestational age and birth weight, a shorter duration of breastfeeding and a longer duration of artificial feeding (AF). Later in childhood, they had higher values of cf-PWV, BMI, FMI and higher prevalence of hypertension. Low maternal gestational weight gain, inadequate fetal development (low birth weight, shorter gestational age) and reduced breastfeeding duration favor APG. Infants with such APG had higher values of cf-PWV, BP, BMI and FMI later in childhood, along with a higher risk of hypertension and obesity. The interaction between APG and a longer duration of AF had a negative effect on cf-PWV (arterial stiffness) and FMI.

Timing of rapid weight gain and its effect on subsequent overweight or obesity in childhood: findings from a longitudinal birth cohort study

BACKGROUND

Rapid weight gain (RWG) has been recognized as an important determinant of childhood obesity. This study aims to explore the RWG distribution among children at six-month intervals from birth to two years old and to examine the association of RWG in each interval with overweight or obesity development in preschool- and school-aged children.

METHODS

Data were obtained from the Taiwan Birth Cohort Study, which is a nationally representative sample of 24,200 children who participated in a face-to-face survey. A total of 17,002 children had complete data both for weight and height at each of the five measurement time periods. Multivariable logistic regression models quantified the relationship between RWG and childhood overweight or obesity.

RESULTS

A total of 17.5% of children experienced rapid weight gain in the first six months of age, compared to only 1.8% of children from 18-24 months. RWG was significantly associated with an increased risk of developing overweight or obesity at 36 months (RWG birth-6 months: OR = 2.6, 95% CI: 2.3-2.8; RWG 18-24 months: OR = 3.7, 95% CI: 2.9-4.6), 66 months (RWG birth-6 months: OR = 2.2, 95% CI: 2.0-2.4; RWG 18-24 months: OR = 2.3, 95% CI: 1.8-2.8), and 8 years of age (RWG birth-6 months: OR = 1.7, 95% CI: 1.6-1.9; RWG 18-24 months: OR = 2.4, 95% CI: 2.0-3.0).

CONCLUSIONS

Childhood RWG increased the risk of subsequent overweight or obesity, regardless of the specific time interval at which RWG occurred before the age of two years. The results reinforce the importance of monitoring childhood RWG continuously and show the risks of childhood RWG with respect to the development of overweight or obesity at preschool and school ages.

Infancy weight gain, parental socioeconomic position, and childhood overweight and obesity: a Danish register-based cohort study

BACKGROUND

Rapid infant weight gain (RIWG) is a very strong predictor of childhood overweight and obesity (COO). Socioeconomic position (SEP) is also related to the risk of COO and parents of different SEP may differ in their reaction to accelerated infant weight gain. Together this could lead to differences in how weight gain and COO risk relate across SEP. This study aimed to analyse possible interaction of SEP and RIWG on COO risk.

METHODS

A register-based longitudinal cohort study followed 19,894 healthy, term infants, born in Denmark between December 2011 and May 2015. Logistic regression models were used to estimate odds ratios (OR) of COO risk at 2 years (22-26 months) of age with 95% confidence intervals (95% CI) for categories of infancy weight gain based on changes in weight-for-age z-scores between 0 and 8-10 months of age (slow (<- 0.67), mean (- 0.67-0.67), rapid (> 0.67-1.34) and very rapid (> 1.34)). Possible multiplicative and additive interaction of SEP (based on household income and maternal education) on the relationship between infancy weight gain and COO were analysed.

RESULTS

In total, 19.1 and 15.1% experienced rapid or very rapid weight gain, respectively, and 1497 (7.5%) children were classified with COO at follow-up. These prevalences were higher in those with lower levels of SEP. Adjusted OR for COO were 3.09 (95% CI [2.66-3.59]) and 7.58 (95% CI [6.51-8.83]) for rapid and very rapid weight gain, respectively, when household income was included in the model. Results were similar in the model including maternal education. No signs of interactions were detected on a multiplicative scale. Weak signs of additive interaction were present, but these values did not reach significance.

CONCLUSION

Both rapid and very rapid weight gain were associated with substantially higher risks of COO but these associations were not modified by SEP. This indicates that promotion of healthy weight gain should take place in all population groups irrespective of their SEP.

Trajectories of body mass index, from adolescence to older adulthood, and pancreatic cancer risk; a population-based case-control study in Ontario, Canada

PURPOSE

Pancreatic cancer has the highest fatality rate of all cancers. Adulthood obesity is an established risk factor for pancreatic cancer; however, life-course obesity is not well understood. The aim of this study was to evaluate the association between body mass index (BMI) trajectories throughout the life-course and pancreatic cancer risk.

METHODS

A population-based case-control study was conducted (2011-2013) in Ontario, Canada. Cases were recruited from the Ontario pancreas cancer study (n = 310) and controls from the Ontario cancer risk factor study (n = 1258). Questionnaires captured self-reported height and weight at four timepoints (adolescence, 20 s, 30-40 s, 50-60 s). BMI trajectories were identified using latent class growth mixture modeling. Odds ratios (OR) and 95% confidence intervals (CI) were estimated from multivariable logistic regression.

RESULTS

Five BMI trajectories were identified: stable-normal weight (38.9%), progressively overweight (42.2%), persistent overweight (12.6%), progressive obesity (4.2%), and persistent obesity (2.1%). The persistent overweight (OR = 1.55; 95% CI 1.02, 2.39) and progressive obesity trajectories (OR = 1.49; 95% CI 0.77, 2.87) compared to stable-normal weight were associated with increased odds of pancreatic cancer. When BMI was evaluated separately the strongest associations with pancreatic cancer emerged in young and mid-adulthood.

CONCLUSION

BMI trajectories characterized by overweight in early adulthood were associated with increased pancreatic cancer risk suggesting a life-course approach to disease risk.

Relative effects of postnatal rapid growth and maternal factors on early childhood growth trajectories

BACKGROUND

A range of postnatal and maternal factors influences childhood obesity, but their relative importance remains unclear. This study aimed to assess the relative impact of postnatal rapid growth and maternal factors on early childhood growth trajectories.

SUBJECTS

Secondary longitudinal analysis of pooled data from the Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program and the InFANT Extend Program (n = 977) was performed. Children's height and weight were collected at birth, 3, 9, 18, and 36/42 months. Body mass index-for-age and height-for-age z-scores (BAZ, HAZ) were computed using WHO growth standards. Mixed-effect polynomial regression models were fitted to examine BAZ and HAZ trajectories and their determinants.

RESULTS

Rapid growth from birth to 3 months, maternal country of birth, and pre-pregnancy BMI were each independently associated with BAZ from 3 to 42 months. Children with rapid growth, those whose mothers were Australian-born, and those whose mothers were overweight/obese pre-pregnancy had higher BAZ from 3 to 42 months. Children with rapid growth had an increase in HAZ growth, but their average HAZ from 3 to 42 months was smaller than children without rapid growth. Children of tall mothers (above average height) had higher HAZ than those of short mothers (below average height). Average HAZ from 3 to 42 months did not differ by maternal country of birth.

CONCLUSION

Children who experienced rapid growth from birth to 3 months, whose mothers were Australian-born or whose mothers were overweight/obese pre-pregnancy demonstrated less favourable growth trajectories across early childhood, potentially predispose them for development of future obesity.

The adiposity rebound in the 21st century children: meaning for what?

With the increase in the prevalence of overweight and obesity worldwide, early adiposity rebound, which is known to have a strong association with obesity, has recently been a focus of research. Early adiposity rebound is conventionally known to have a close relationship with non-communicable diseases. However, novel insights into early adiposity rebound have implied an acceleration of growth and puberty, which is directly reflected in the trends in the timing of adiposity rebound, in the 21st century compared with in the past. Furthermore, the observation that lean mass changes rather than fat mass changes show a more similar pattern to body mass index trajectories is interesting. In this article, the later outcomes and risk factors of early adiposity rebound are briefly summarized, and the current trends in the timing of adiposity rebound and novel insights into its relationship with body composition are reviewed.

Body Mass Index Changes in Early Childhood

OBJECTIVE

To longitudinally investigate body mass index (BMI) in young children in Ireland and identify factors and critical time points associated with changes in BMI.

STUDY DESIGN

Data on 11 134 children were collected in the nationally representative Growing Up in Ireland infant cohort study. Height and weight were measured at 9 months, 3 years, and 5 years of age. Multilevel regression was used to identify risk factors associated with changes in BMI over time (n = 10 377), combining a unique set of covariates collected from the child and the 2 main caregivers (usually the mother and father).

RESULTS

The proportion of children ≥85th percentile of World Health Organization growth criteria was 39% at 9 months, 44% at 3 years, and 30% at 5 years. Children born large for gestational age (13%) and those with rapid infant weight gain (25%) consistently had higher BMI. Low average BMIs were consistently seen in children born small for gestational age (10%) or before 37 weeks (7%). Smaller variations in BMI existed for other factors including ethnicity, household structure, caregiver weight status, breastfeeding, sex, socioeconomic status, sleeping hours, childcare, and region.

CONCLUSIONS

In this study, differences at birth and in infancy appear to be most strongly associated with variation in BMI at all ages. Nevertheless, belonging to a number of other high-risk groups cumulatively could lead children to develop critical weight states. Policy-makers should target families with interventions before and during pregnancy when dominant risk factors are still modifiable. Longer-term follow-up of children may be needed to study associations later in childhood.

Fetal and Infancy Growth Pattern, Cord and Early Childhood Plasma Leptin, and Development of Autism Spectrum Disorder in the Boston Birth Cohort

Leptin is a proinflammatory cytokine that plays an important role in energy homeostasis. Emerging evidence suggests that leptin levels are altered in children with autism spectrum disorder (ASD); however, this has not been studied prospectively. Rapid growth during infancy and early childhood has been implicated in ASD, but the evidence is inconsistent. As leptin is involved in growth and is a potential risk factor for ASD, we explored the associations between (a) cord, early childhood leptin and ASD; and (b) birth weight for gestational age, early childhood weight gain, and ASD. We also assessed the mediating role of leptin in the relationship between weight gain during infancy and ASD. This study was conducted in a sample of 822 subjects from the Boston Birth Cohort. ASD was defined from diagnostic codes in electronic medical records. Extremely rapid weight gain during infancy was associated with a greater ASD risk and this persisted after adjusting for potential confounders (aOR: 3.11; 95% CI: 1.37, 7.07). Similarly, children that had higher plasma leptin levels, prior to ASD diagnosis, had an increased ASD risk in both unadjusted and adjusted models (aOR: 7.87; 95% CI: 2.06, 30.04). Further, early childhood leptin indirectly mediated the relationship between rapid weight gain and ASD. No associations were found between birth weight for gestational age, cord leptin and risk of ASD. Our findings provide a basis to further explore whether the combination of early life growth pattern and a biomarker such as leptin can predict ASD earlier. Autism Res 2018, 11: 1416-1431. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Is early life growth and a biomarker leptin related to ASD risk? To answer this question, we followed 822 children from birth and found that those who gained weight very quickly in infancy, had higher leptin levels in early childhood, had a greater chance of later ASD diagnosis. More research is needed to see if infant's weight gain pattern along with a biomarker (such as leptin) can be used to identify children with ASD sooner.

Growth curves and their associated weight and height factors in children from birth to 4 years old in West Azerbaijan Province, northwest Iran

BACKGROUND

Growth trajectory standards are important components that need to be monitored for suitable child growth. This study examined longitudinal data to identify the factors affecting growth trajectory standards of height and weight for infants.

METHODS

This study included 566 neonates (286 boys and 280 girls) born in West Azerbaijan Province, northwest Iran, who were followed from birth to 4 years of age. The subjects' weight and height were recorded at birth, 1, 2, 4, 6, 9 months and 1, 1.5, 2, 3, and 4 years of age. In this study, the Lambda-Mu-Sigma (LMS) method was used to construct the growth curves for each measure. The linear mixed model was employed to determine the factors affecting the growth trajectory.

RESULTS

The study demonstrates that the place of birth, duration of breastfeeding, and infants' gender had a significant effect on the growth trajectory. Nonetheless, other variables did not have any significant effect on growth. Growth curves for significant factors of weight and height (5th, 50th, 95th percentiles) were obtained. There was a rapid increase in the growth curve from birth to 2 years of age, which then remained relatively constant up to 4 years of age.

DISCUSSION

This paper provides the first local growth trajectory standards of height and weight for infants by analyzing longitudinal measurements in West Azerbaijan province. This study determined the factors affecting the growth trend in both indices. It seems that there was a significant difference in the growth trajectories of infants in subgroups of the effective factor.

Infant Weight and Length Growth Trajectories Modeled Using Superimposition by Translation and Rotation Are Differentially Associated with Body Composition Components at 3 and 7 Years of Age

OBJECTIVE

To evaluate how infant weigh and length growth trajectories associate with body composition at 3 and 7 years because previous studies have noted that rapid infant weight gain increases risk for high body mass index (BMI) in children.

STUDY DESIGN

There were 322 children enrolled at 3 years of age with dual x-ray absorptiometry body composition data and pediatrician growth data for 0-2 years of age who were included in analysis. Superimposition by translation and rotation modeling was used to characterize infant weight and length trajectories in terms of size, tempo and velocity measures. Associations of these measures with fat mass, lean mass, percent body fat, bone mineral content, BMI z-score, and overweight prevalence at 3 and 7 years of age were determined.

RESULTS

Infant growth trajectories differed by sex, race, and breastfeeding status. Higher overall weight size and weight velocity from 0 to 2 years of age were associated positively with all age 3 body composition and anthropometry outcomes. However, longer length size from 0 to 2 years of age was associated independently with higher bone mineral content and lean mass, but lower percent body fat, BMI z-score, and a lower odds of overweight at 3 years of age. By 7 years of age, later than average infant weight tempo was also associated with lower fat mass, lean mass, and BMI z-score.

CONCLUSIONS

Greater average weight size and greater weight velocity in infancy are markers for greater overall body size at 3 and 7 years of age. However, longer average lengths and later weight gain tempo between 0 and 2 years of age may help to establish a leaner body composition by 3 and 7 years of age.

Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review

Childhood obesity in the United States has doubled over the last three decades and currently affects 17% of children and adolescents. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stressors found in a child's environment and how these interactions affect a child's health and well-being. The objectives of this systematic scoping review were to (1) identify potential chemical stressors in the context of non-chemical stressors that impact childhood obesity; and, (2) summarize our observations for chemical and non-chemical stressors in regards to child-specific environments within a community setting. A review was conducted to identify chemical and non-chemical stressors related to childhood obesity for the childhood life stages ranging from prenatal to adolescence. Stressors were identified and grouped into domains: individual behaviors, family/household behaviors, community stressors, and chemical exposures. Stressors were related to the child and the child's everyday environments and used to characterize child health and well-being. This review suggests that the interactions of chemical and non-chemical stressors are important for understanding a child's overall health and well-being. By considering these relationships, the exposure science research community can better design and implement strategies to reduce childhood obesity.

Pacifier Use and Early Life Weight Outcomes in the Intervention Nurses Start Infants Growing on Healthy Trajectories Study

BACKGROUND

Although widely used by infants, little is known about the long-term effects of pacifiers. We investigated relationships between pacifier use in infancy and appetite, temperament, feeding, and weight outcomes through age 2 years using data from the Intervention Nurses Start Infants Growing on Healthy Trajectories study.

METHODS

Mother-newborn dyads were randomized to a responsive parenting intervention for obesity prevention or a control group. Infants with data on pacifier use (n = 250) were categorized as using a pacifier beyond early infancy (≥4 months of age) or not. Anthropometrics were measured at 6 months, 1, and 2 years with overweight defined as weight-for-length ≥95th percentile at 1 year and BMI ≥85th percentile at 2 years. Mothers completed questionnaires on temperament, appetite, and feeding.

RESULTS

Infants who used a pacifier at 4 months or later (68%) had greater conditional weight gain from birth to 6 months (p = 0.01), weight-for-length z-score at 1 year (p < 0.001), and BMI z-score at 2 years (p < 0.001) than infants who did not. Infants using a pacifier at ≥4 months were more likely to be overweight at ages 1 year (11.7% vs. 1.3%, p = 0.03) and 2 years (20.1% vs. 7.9%, p = 0.03). Pacifier use was associated with shorter breastfeeding duration and less responsive parent feeding styles, but these variables did not mediate the relationship between pacifiers and weight. Parent-reported temperament and appetite were unrelated to pacifier use.

CONCLUSIONS

Pacifier use beyond early infancy is associated with accelerated infant growth and toddler overweight, although the reasons for this relationship are unclear.

Does the association between early life growth and later obesity differ by race/ethnicity or socioeconomic status? A systematic review

PURPOSE

Rapid growth during infancy predicts higher risk of obesity later in childhood. The association between patterns of early life growth and later obesity may differ by race/ethnicity or socioeconomic status (SES), but prior evidence syntheses do not consider vulnerable subpopulations.

METHODS

We systemically reviewed published studies that explored patterns of early life growth (0-24 months of age) as predictors of later obesity (>24 months) that were either conducted in racial/ethnic minority or low-SES study populations or assessed effect modification of this association by race/ethnicity or SES. Literature searches were conducted in PubMed and SocINDEX.

RESULTS

Ten studies met the inclusion criteria. Faster growth during the first 2 years of life was consistently associated with later obesity irrespective of definition and timing of exposure and outcome measures. Associations were strongest in populations composed of greater proportions of racial/ethnic minority and/or low-SES children. For example, ORs ranged from 1.17 (95% CI: 1.11, 1.24) in a heterogeneous population to 9.24 (95% CI: 3.73, 22.9) in an entirely low-SES nonwhite population.

CONCLUSIONS

The impact of rapid growth in infancy on later obesity may differ by social stratification factors such as race/ethnicity and family income. More robust and inclusive studies examining these associations are needed.

Maternal acculturation and the growth of impoverished Mexican American infants

OBJECTIVE

Identification of early life risk factors that predispose low-income Hispanic children to obesity is critical. For low-income Mexican American mothers, the cultural context may influence maternal experience and behaviors relevant to infant weight and growth.

METHODS

In a longitudinal study of 322 low-income Mexican American mother-infant dyads, linear growth modeling examined the relation of maternal acculturation to infant weight gain across the first year and evaluated birth outcomes, breastfeeding, and maternal BMI as mediators.

RESULTS

There was a high prevalence (36% >95th percentile) of infants with obesity at 1 year. Higher maternal acculturation was associated with lower birth weight, higher infant weight at 6 weeks, and a lower prevalence of breastfeeding. Mediation analyses supported formula-feeding as a mediator of the relation between higher maternal acculturation and an increasing slope of infant weight gain across the first year.

CONCLUSIONS

Breastfeeding may have measurable benefits for Mexican American child obesity status in this high-risk population, particularly among those with more acculturated mothers.

Cord blood leptin and gains in body weight and fat mass during infancy

OBJECTIVES

Low early-life leptin concentrations may promote faster weight gain in infancy. We aimed to examine the associations between cord blood leptin concentrations and changes in weight and body composition during infancy.

DESIGN AND METHODS

Serum leptin was measured at 15 weeks gestation, in umbilical cord blood collected at delivery and at 2 years in 334 children from the Cork Baseline Birth Cohort Study. Body composition was measured at 2 days and 2 months using air displacement plethysmography. Conditional change in weight standard deviation scores over a number of age intervals in the first 2 years and conditional change in fat mass index (FMI) and fat-free mass index (FFMI) (kg/(length)m(2)) between birth and 2 months were calculated and associations with cord blood leptin were examined using linear regression.

RESULTS

At birth, cord blood leptin was positively correlated with FMI (r = 0.48, P < 0.001) and showed a weaker correlation with FFMI (r = 0.12, P = 0.05). After adjustment for confounders, higher cord blood leptin (per ng/mL) was associated with slower conditional weight gain between birth and 2 months (β (95% CI): -0.024 (-0.035, -0.013), P < 0.001) but not over subsequent age intervals. Cord blood leptin was also inversely associated with conditional change in FMI (-0.021 (-0.034, -0.007, P = 0.003) but not FFMI between birth and 2 months.

CONCLUSIONS

These are the first data to show that associations between higher cord blood leptin and slower weight gain during infancy are driven by lower increases in adiposity, at least in early infancy.

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

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

Race/Ethnic Differences in Birth Size, Infant Growth, and Body Mass Index at Age Five Years in Children in Hawaii

BACKGROUND

Factors at birth and infancy may increase risk of being overweight in childhood. The aim of this study was to examine the relationship of birth size and infant growth (2-24 months) with BMI at age 5 years in a multiethnic population.

METHODS

This was a retrospective study (using electronic medical records of a health maintenance organization in Hawaii) of singleton children born in 2004-2005, with linked maternal and birth information, infant weights (n = 597) and lengths (n = 473) in the first 2 years, and BMI measures at age 5 years (n = 894). Multiple regression models were used to estimate the association of BMI at age 5 years with birth size and infant growth.

RESULTS

Birth weight was positively associated with BMI at age 5 years, adjusting for gestational age, sex, race/ethnicity, and maternal prepregnancy weight, age, education, and smoking. A greater change in infant weight was associated with a higher BMI at age 5 years, though the effect of birth weight on BMI was neither mediated nor modified by infant growth rate. Birth weight, change in infant weight, and BMI at age 5 years varied by race/ethnicity. Change in infant BMI in the first 2 years was higher in other Pacific Islanders and whites (Δ = 0.966; confidence interval [CI] = 0.249-1.684; p = 0.02) than in Asian, other, and part Native Hawaiian race/ethnic groups.

CONCLUSIONS

Early biological measures of birth weight and infant weight gain varied by race/ethnicity and positively predicted BMI at age 5 years.

Determinants of Weight Gain during the First Two Years of Life--The GECKO Drenthe Birth Cohort

Objectives

To explain weight gain patterns in the first two years of life, we compared the predictive values of potential risk factors individually and within four different domains: prenatal, nutrition, lifestyle and socioeconomic factors.

Methods

In a Dutch population-based birth cohort, length and weight were measured in 2475 infants at 1, 6, 12 and 24 months. Factors that might influence weight gain (e.g. birth weight, parental BMI, breastfeeding, hours of sleep and maternal education) were retrieved from health care files and parental questionnaires. Factors were compared with linear regression to best explain differences in weight gain, defined as changes in Z-score of weight-for-age and weight-for-length over 1–6, 6–12 and 12–24 months. In a two-step approach, factors were first studied individually for their association with growth velocity, followed by a comparison of the explained variance of the four domains.

Results

Birth weight and type of feeding were most importantly related to weight gain in the first six months. Breastfeeding versus formula feeding showed distinct growth patterns in the first six months, but not thereafter. From six months onwards, the ability to explain differences in weight gain decreased substantially (from R²_total = 38.7% to R²_total<7%).

Conclusion

Birth weight and breast feeding were most important to explain early weight gain, especially in the first six months of life. After the first six months of life other yet undetermined factors start to play a role.

The study of women, infant feeding and type 2 diabetes after GDM pregnancy and growth of their offspring (SWIFT Offspring study): prospective design, methodology and baseline characteristics

BACKGROUND

Breastfeeding is associated with reduced risk of becoming overweight or obese later in life. Breastfed babies grow more slowly during infancy than formula-fed babies. Among offspring exposed in utero to maternal glucose intolerance, prospective data on growth during infancy have been unavailable. Thus, scientific evidence is insufficient to conclude that breastfeeding reduces the risk of obesity among the offspring of diabetic mothers (ODM). To address this gap, we devised the Study of Women, Infant Feeding and Type 2 Diabetes after GDM Pregnancy and Growth of their Offspring, also known as the SWIFT Offspring Study. This prospective, longitudinal study recruited mother-infant pairs from the SWIFT Study, a prospective study of women with recent gestational diabetes mellitus (GDM). The goal of the SWIFT Offspring Study is to determine whether breastfeeding intensity and duration, compared with formula feeding, are related to slower growth of GDM offspring during the first year life. This article details the study design, participant eligibility, data collection, and methodologies. We also describe the baseline characteristics of the GDM mother-infant pairs.

METHODS

The study enrolled 466 mother-infant pairs among GDM deliveries in northern California from 2009-2011. Participants attended three in-person study exams at 6-9 weeks, 6 months and 12 months after delivery for infant anthropometry (head circumference, body weight, length, abdominal circumference and skinfold thicknesses), as well as maternal anthropometry (body weight, waist circumference and percent body fat). Mothers also completed questionnaires on health and lifestyle behaviors, including infant diet, sleep and temperament. Breastfeeding intensity and duration were assessed via several sources (diaries, telephone interviews, monthly mailings and in-person exams) from birth through the first year of life. Pregnancy course, clinical perinatal and newborn outcomes were obtained from health plan electronic medical records. Infant saliva samples were collected and stored for genetics studies.

DISCUSSION

This large, racially and ethnically diverse cohort of GDM offspring will enable evaluation of the relationship of infant feeding to growth during infancy independent of perinatal characteristics, sociodemographics and other risk factors. The longitudinal design provides the first quantitative measures of breastfeeding intensity and duration among GDM offspring during early life.

The prevalence of rapid weight gain in infancy differs by the growth reference and age interval used for evaluation

BACKGROUND

Infant rapid weight gain (RWG) may predict subsequent obesity, but there are inconsistencies in the growth references and age intervals used for assessment.

METHODS

This study evaluated whether the prevalence of RWG (an increase of >0.67 in weight-for-age z-score) differed by growth reference (2006 WHO standards vs 2000 CDC references) and age interval of assessment (0-3, 0-6, 6-12 and 0-12 months). Pooled data from singleton term infants from two observational studies on maternal mood disorders during pregnancy were used (n = 161). Differences in RWG prevalence by growth reference and age interval were tested using Cochran's Q and McNemar's tests.

RESULTS

The CDC reference produced a higher RWG prevalence (14% of infants additionally categorized as RWG, p < 0.0001) within the 0-3 month age interval compared to the WHO standards; this pattern was reversed for the 6-12 and 0-12 month intervals. RWG prevalence did not differ across age interval within the WHO standards, but did differ with the CDC references (range: 22% for 0-3 months to 4.2% for 6-12 months, p < 0.0001).

CONCLUSIONS

Caution is advised when comparing studies with different criteria for RWG. Future studies should use the 2006 WHO standards and a consistent age interval of evaluation.

Maternal smoking during pregnancy and growth in infancy: a covariance structure analysis

Background

Smoking during pregnancy is related to fetal constraint and accelerated postnatal growth. However, the pathways between these factors have not been clarified. Pathway analyses that link these factors can help us better understand the mechanisms involved in this association. Therefore, this study aimed to examine pathways between maternal smoking during pregnancy and growth in infancy.

Methods

Participants were singletons born between 1993 and 2006 in rural Japan. The outcome was the change in weight z-score between birth and 3 years of age. Pathways from maternal smoking and other maternal factors (such as maternal body mass index and work status) to growth in infancy via birth factors (such as birth weight and gestational age) and breastfeeding were examined using structural equation modeling.

Results

Complete data were available for 1524 children (775 boys and 749 girls). The model fit appeared adequate. Lower birth weight and non-exclusive breastfeeding mediated the association between maternal smoking during pregnancy and rapid growth in infancy. Maternal smoking was also directly linked to rapid growth in infancy (standardized direct effects 0.06, P = 0.002). Taking all pathways into account, the standardized total effect of maternal smoking on growth in infancy was 0.11.

Conclusions

Maternal smoking during pregnancy may both indirectly, through birth weight and breastfeeding status, and directly influence growth during infancy; however, there may be other pathways that have not yet been identified.

Antepartum determinants of rapid early-life weight gain in term infants born to women with and without gestational diabetes

OBJECTIVE

Rapid weight gain in the first 3 months of life has been associated with an unfavourable cardio-metabolic phenotype in adulthood. However, little is known about the antepartum determinants of this rapid weight gain, which may reflect key developmental exposures that program metabolic pathways. Thus, we sought to characterize the antepartum determinants of rapid weight gain in the first 3 months of life in infants exposed to gestational diabetes mellitus (GDM), a patient population at risk for early cardio-metabolic disease.

DESIGN

Prospective observational cohort study.

PATIENTS

Pregnant women with (n = 90) and without GDM (n = 250) underwent detailed antepartum metabolic characterization, followed by assessment of their term offspring at age 3 months.

MEASUREMENTS

Rapid infant weight gain in the first 3 months was defined as weight gain ≥ 0·5 SD.

RESULTS

No features of maternal metabolic function in pregnancy (including insulin sensitivity, lipid profile, adiponectin, leptin and C-reactive protein) were associated with infant weight gain in either the GDM or non-GDM group. Interestingly, although all infants were born at term (≥37 weeks), length of gestation was inversely associated with weight gain at 3 months in the infants of women with GDM (β = -148·5, P = 0·01). In these infants, length of gestation <39 weeks was an independent predictor of rapid weight gain (OR = 7·9, 95%CI 1·7-38, P = 0·009) in the fully adjusted model. These associations were not observed in infants of women without GDM.

CONCLUSIONS

Delivery before 39 weeks is independently associated with rapid weight gain in the first 3 months of life in term infants of women with GDM and hence may be an antepartum marker of future cardio-metabolic risk.

The Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) study

Background

Because early life growth has long-lasting metabolic and behavioral consequences, intervention during this period of developmental plasticity may alter long-term obesity risk. While modifiable factors during infancy have been identified, until recently, preventive interventions had not been tested. The Intervention Nurses Starting Infants Growing on Healthy Trajectories (INSIGHT). Study is a longitudinal, randomized, controlled trial evaluating a responsive parenting intervention designed for the primary prevention of obesity. This “parenting” intervention is being compared with a home safety control among first-born infants and their parents. INSIGHT’s central hypothesis is that responsive parenting and specifically responsive feeding promotes self-regulation and shared parent–child responsibility for feeding, reducing subsequent risk for overeating and overweight.

Methods/Design

316 first-time mothers and their full-term newborns were enrolled from one maternity ward. Two weeks following delivery, dyads were randomly assigned to the “parenting” or “safety” groups. Subsequently, research nurses conduct study visits for both groups consisting of home visits at infant age 3–4, 16, 28, and 40 weeks, followed by annual clinic-based visits at 1, 2, and 3 years. Both groups receive intervention components framed around four behavior states: Sleeping, Fussy, Alert and Calm, and Drowsy. The main study outcome is BMI z-score at age 3 years; additional outcomes include those related to patterns of infant weight gain, infant sleep hygiene and duration, maternal responsiveness and soothing strategies for infant/toddler distress and fussiness, maternal feeding style and infant dietary content and physical activity. Maternal outcomes related to weight status, diet, mental health, and parenting sense of competence are being collected. Infant temperament will be explored as a moderator of parenting effects, and blood is collected to obtain genetic predictors of weight status. Finally, second-born siblings of INSIGHT participants will be enrolled in an observation-only study to explore parenting differences between siblings, their effect on weight outcomes, and carryover effects of INSIGHT interventions to subsequent siblings.

Discussion

With increasing evidence suggesting the importance of early life experiences on long-term health trajectories, the INSIGHT trial has the ability to inform future obesity prevention efforts in clinical settings.

Trial registration

NCT01167270. Registered 21 July 2010.

Differences in BMI z-scores between offspring of smoking and nonsmoking mothers: a longitudinal study of German children from birth through 14 years of age

BACKGROUND

Children of mothers who smoked during pregnancy have a lower birth weight but have a higher chance to become overweight during childhood.

OBJECTIVES

We followed children longitudinally to assess the age when higher body mass index (BMI) z-scores became evident in the children of mothers who smoked during pregnancy, and to evaluate the trajectory of changes until adolescence.

METHODS

We pooled data from two German cohort studies that included repeated anthropometric measurements until 14 years of age and information on smoking during pregnancy and other risk factors for overweight. We used longitudinal quantile regression to estimate age- and sex-specific associations between maternal smoking and the 10th, 25th, 50th, 75th, and 90th quantiles of the BMI z-score distribution in study participants from birth through 14 years of age, adjusted for potential confounders. We used additive mixed models to estimate associations with mean BMI z-scores.

RESULTS

Mean and median (50th quantile) BMI z-scores at birth were smaller in the children of mothers who smoked during pregnancy compared with children of nonsmoking mothers, but BMI z-scores were significantly associated with maternal smoking beginning at the age of 4-5 years, and differences increased over time. For example, the difference in the median BMI z-score between the daughters of smokers versus nonsmokers was 0.12 (95% CI: 0.01, 0.21) at 5 years, and 0.30 (95% CI: 0.08, 0.39) at 14 years of age. For lower BMI z-score quantiles, the association with smoking was more pronounced in girls, whereas in boys the association was more pronounced for higher BMI z-score quantiles.

CONCLUSIONS

A clear difference in BMI z-score (mean and median) between children of smoking and nonsmoking mothers emerged at 4-5 years of age. The shape and size of age-specific effect estimates for maternal smoking during pregnancy varied by age and sex across the BMI z-score distribution.

Association of pre- and post-natal parental smoking with offspring body mass index: an 8-year follow-up of a birth cohort

BACKGROUND

Although many epidemiological studies have shown an association between maternal smoking during pregnancy and offspring overweight, it is still under debate whether intrauterine tobacco smoke exposure directly affects offspring obesity or if the association is rather due to confounding by lifestyle factors.

OBJECTIVES

The association of parental smoking habits at pre- and post-natal periods with offspring body mass index (BMI) was investigated, whereas maternal smoking during pregnancy was validated by cord serum cotinine measurements.

METHODS

Multivariable linear regression analysis, based on the German Ulm Birth Cohort Study of 1045 children born in 2000 with annual/biennial follow-up until the age of 8 years (n = 609), was conducted.

RESULTS

BMI of offspring from mothers who smoked during pregnancy and non-smoking mothers differed significantly at 8 years. Maternal smoking during pregnancy was associated with an increase in BMI of 0.73 kg m(-2) [95% confidence interval: 0.21-1.25] in 8-year-old children after adjustment for multiple potential confounding variables. Both pre- and post-natal smoking of fathers (0.34 [0.01-0.66]/0.45 [0.08-0.81]) and of both parents (1.03 [0.43-1.63]/0.56 [0.14-0.98]) were likewise significantly associated with offspring BMI.

CONCLUSIONS

The observed patterns suggest that residual confounding by living conditions in smoking families rather than specific intrauterine exposure to tobacco smoke may account for the increased risk of offspring overweight.

Overweight in adolescence can be predicted at age 6 years: a CART analysis in German cohorts

OBJECTIVE

To examine, whether overweight in adolescents can be predicted from the body mass index (BMI) category, at the age of 6, the mother's education level and mother's obesity and to quantify the proportion of overweight at the age of 14 that can be explained by these predictors.

METHOD

Pooled data from three German cohorts providing anthropometric and other relevant data to a total of 1 287 children. We used a classification and regression tree (CART) approach to identify the contribution of BMI category at the age of 6 (obese: BMI > 97th percentile (P97); overweight: P90 < BMI ≤ P97; high normal weight: P75P90) at the age of 14.

RESULTS

While 4.8% [95%CI: 3.2;7.0] of 651 boys and 4.1% [95%CI: 2.6;6.2] of 636 girls with a BMIP97 (similar results for girls). BM I ≥ P75 at the age of 6 explained 63.5% [95%CI: 51.1;74.5]) and 72.0% [95%CI: 60.4;81.8] of overweight/obesity at the age of 14 in boys and girls, respectively.

CONCLUSIONS

Overweight/obesity in adolescence can be predicted by BMI category at the age of 6 allowing for parent counselling or risk guided interventions in children with BMI ≥ P75, who accounted for >2/3 of overweight/obesity in adolescents.

Exclusive breastfeeding for 4 versus 6 months and growth in early childhood

AIM

To investigate the growth and the prevalence of overweight in early childhood among infants exclusively breastfed for 6 months (EBF) compared with those receiving complementary foods from 4 months of age in addition to breast milk (CF).

METHODS

A total of 119 mother-infant pairs were randomised either in the CF or in the EBF group. Weight, length and head circumference of the infants were measured at birth, 6 weeks, and 3-6 months of age. In the follow-up, the children's weight, length and head circumference were measured at 8, 10, 12 and 18 months and weight and height at 29-38 months.

RESULTS

There were no differences between groups in the anthropometric outcome measures of weight-for-age (p = 0.78), length-for-age (p = 0.59), head-circumference-for-age (p = 0.82) and BMI-for-age (p = 0.61), using repeated measurements ANOVA. Furthermore, no difference was seen in the prevalence between groups in risk of being overweight or in those who were overweight at 18 months and 29-38 months of age.

CONCLUSION

Exclusive breastfeeding for the first 4 or 6 months of life does not seem to affect the risk of being overweight or the prevalence of those who were overweight in early childhood.

Associated factors for accelerated growth in childhood: a systematic review

Several studies have shown that accelerated growth in the postnatal period is critical for the development of chronic diseases. The term catch-up has been used for the accelerated growth of children who have suffered some sort of restriction of nutrition or oxygen supply. However, accelerated growth has been observed among children who have an appropriate birth weight for their gestational age (AGA) and with no apparent morbidity. Therefore, this systematic review was carried out on the associated factors of accelerated growth, or catch-up, using the Medline/Pubmed database. Only cohort studies written in Portuguese, English or Spanish, with children between zero and 12 years old who presented accelerated growth or catch-up as the outcome were included. Out of the 2,155 articles found, 9 were selected. There is no uniformity in the operational definition of accelerated growth, or in the concept of catch-up. According to this review, accelerated growth is associated with primiparity, maternal smoking during pregnancy, lower birth weight, and early weaning. The main limitations in the available literature are the high number of follow-up losses and the lack of control for confounding factors. The determinants of accelerated growth still need to be studied further, especially among AGA children.

Estimating overweight risk in childhood from predictors during infancy

OBJECTIVE

The aim of this study was to develop and validate a risk score algorithm for childhood overweight based on a prediction model in infants.

METHODS

Analysis was conducted by using the UK Millennium Cohort Study. The cohort was divided randomly by using 80% of the sample for derivation of the risk algorithm and 20% of the sample for validation. Stepwise logistic regression determined a prediction model for childhood overweight at 3 years defined by the International Obesity Task Force criteria. Predictive metrics R(2), area under the receiver operating curve (AUROC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

Seven predictors were found to be significantly associated with overweight at 3 years in a mutually adjusted predictor model: gender, birth weight, weight gain, maternal prepregnancy BMI, paternal BMI, maternal smoking in pregnancy, and breastfeeding status. Risk scores ranged from 0 to 59 corresponding to a predicted risk from 4.1% to 73.8%. The model revealed moderately good predictive ability in both the derivation cohort (R(2) = 0.92, AUROC = 0.721, sensitivity = 0.699, specificity = 0.679, PPV = 38%, NPV = 87%) and validation cohort (R(2) = 0.84, AUROC = 0.755, sensitivity = 0.769, specificity = 0.665, PPV = 37%, NPV = 89%).

CONCLUSIONS

Using a prediction algorithm to identify at-risk infants could reduce levels of child overweight and obesity by enabling health professionals to target prevention more effectively. Further research needs to evaluate the clinical validity, feasibility, and acceptability of communicating this risk.

The Maternal Obesity Management (MOM) Trial Protocol: a lifestyle intervention during pregnancy to minimize downstream obesity

BACKGROUND

Maternal obesity and/or high gestational weight gain (GWG) are associated with downstream child obesity. Pregnancy represents a critical period for prevention as women are highly motivated and more receptive to behavior change.

OBJECTIVE

This pilot study was developed to test the feasibility of intervening with the mother, specifically keeping her GWG within the Institute of Medicine (IOM) limits, with the intended target of preventing obesity in her child downstream. We are testing the practicality of delivering a structured physical activity and nutrition intervention to pregnant women during gestation and then following mom and baby to 24 months of age.

STUDY DESIGN

This study is a two-arm, parallel group, randomized controlled trial being conducted in Ottawa. Pregnant women, with pregravid BMI >18.5, between 12 and 20 weeks gestation are randomized to one of two groups: intervention (n=30) who receive the MOM trial Handbook (guide to healthy gestation) plus a structured physical activity and nutrition program, or a standard clinical care control group (n=30). The intervention lasts 25-28 weeks (6 months) depending on anticipated delivery date, with follow-up assessment on mother and child at 3, 6, 12 and 24 months post-delivery.

SIGNIFICANCE

Pregnancy, a critical time of growth, development and physiological change, provides an opportunity for early lifestyle intervention. The goal of identifying an effective lifestyle program for the gestational period that leads to healthy fetal development and subsequently normal weight offspring, less likely to develop obesity and its co-morbidities, is unique and could possibly attenuate the inter-generational cycle of obesity.

Growth during infancy and childhood, and adiposity at age 16 years: ages 2 to 7 years are pivotal

OBJECTIVE

To assess the period during infancy and childhood in which growth is most associated with adolescent adiposity and the metabolic syndrome (MS) and whether this differs depending on maternal smoking during pregnancy.

STUDY DESIGN

A longitudinal population-based cohort study among 772 girls and 708 boys.

RESULTS

Weight gains between ages 2-4 years and ages 4-7 years were most strongly associated with higher body mass index (BMI), sum of skinfold measurements, body fat percentage, and waist circumference at age 16. A one SD increase in weight between ages 2-4 and 4-7 years was associated with increases in outcome measures of +0.82 to +1.47 SDs (all P < .001), and with a less favorable MS score. In children whose mothers smoked during pregnancy, the association of relative weight gain during ages 2-4 years with adolescent BMI was stronger than in children whose mothers did not smoke. For adolescent BMI, the increase was 0.42 SD higher (P = .01). This was similar for the other adiposity measures.

CONCLUSIONS

Large relative increases in weight from ages 2 to 7 years are associated with adolescent adiposity and MS. This is more pronounced in adolescents whose mothers smoked during pregnancy.

Evaluation of the association between maternal smoking, childhood obesity, and metabolic disorders: a national toxicology program workshop review

BACKGROUND

An emerging literature suggests that environmental chemicals may play a role in the development of childhood obesity and metabolic disorders, especially when exposure occurs early in life.

OBJECTIVE

Here we assess the association between these health outcomes and exposure to maternal smoking during pregnancy as part of a broader effort to develop a research agenda to better understand the role of environmental chemicals as potential risk factors for obesity and metabolic disorders.

METHODS

PubMed was searched up to 8 March 2012 for epidemiological and experimental animal studies related to maternal smoking or nicotine exposure during pregnancy and childhood obesity or metabolic disorders at any age. A total of 101 studies-83 in humans and 18 in animals-were identified as the primary literature.

DISCUSSION

Current epidemiological data support a positive association between maternal smoking and increased risk of obesity or overweight in offspring. The data strongly suggest a causal relation, although the possibility that the association is attributable to unmeasured residual confounding cannot be completely ruled out. This conclusion is supported by findings from laboratory animals exposed to nicotine during development. The existing literature on human exposures does not support an association between maternal smoking during pregnancy and type 1 diabetes in offspring. Too few human studies have assessed outcomes related to type 2 diabetes or metabolic syndrome to reach conclusions based on patterns of findings. There may be a number of mechanistic pathways important for the development of aberrant metabolic outcomes following perinatal exposure to cigarette smoke, which remain largely unexplored.

CONCLUSIONS

From a toxicological perspective, the linkages between maternal smoking during pregnancy and childhood overweight/obesity provide proof-of-concept of how early-life exposure to an environmental toxicant can be a risk factor for childhood obesity.