Postnatal weight and height growth velocities at different ages between birth and 5 y and body composition in adolescent boys and girls

Use of the Dietary Guideline Index to assess cardiometabolic risk in adolescents

The long-term adherence to the dietary guidelines has not been evaluated against emergence of cardiometabolic risks in adolescents with increasing rates of obesity. The present study aimed to (1) determine the level of adherence to the guidelines using the Australian Dietary Guideline Index for Children and Adolescents (DGI-CA) in adolescents of age 14 and 17 years and to (2) examine the relationship between their assessed diet quality and concurrently measured cardiometabolic risk factors over time. Data were analysed from the Western Australian Pregnancy Cohort (Raine) Study. The DGI-CA was determined from a FFQ. Anthropometry and fasting biochemical measures were taken using standard procedures. Hierarchical linear mixed models examined associations between cardiometabolic risk factors and DGI-CA, adjusting for socio-economic status, physical activity, BMI, and sex, and examining for interactions. The mean DGI-CA scores were 47·1 (sd 10·2) at 14 years (n 1419) and 47·7 (sd 11·0) at 17 years (n 843), and were not different between sex. There was a significant inverse association between DGI-CA and insulin, homeostasis model assessment score and heart rate. The DGI-CA was positively associated with BMI (P= 0·029) but negatively with waist:hip ratio (P= 0·026). It was not associated with lipids or blood pressure, with the exception of a negative association with TAG (P= 0·011). The degree of adherence in the Raine Study adolescents was suboptimal but similar to the Australian Children's Nutrition and Physical Activity Survey. The present study shows that, at any particular time, better diet quality was associated with better insulin sensitivity and TAG levels and decreased abdominal fatness.

Associations between menarche-related genetic variants and pubertal growth in male and female adolescents

PURPOSE

Previous studies have identified novel genetic variants associated with age at menarche in females of European descent. The pubertal growth effects of these variants have not been carefully evaluated in non-European descent groups. We aimed to examine the effects of 31 newly identified menarche-related single-nucleotide polymorphisms (SNPs) on growth outcomes in African-American (AA) and European-American (EA) children in a prospective cohort.

METHODS

We analyzed longitudinal data collected from 263 AAs and 338 EAs enrolled between ages 5 and 17 years; the subjects were followed semiannually for an average of 6 years. The associations between the SNPs and growth-related outcomes, including weight, height, and body mass index (BMI), were examined using mixed-effect models.

RESULTS

Longitudinal analyses revealed that 4 (near or in genes VGLL3, PEX2, CA10, and SKOR2) of the 14 menarche-only-related SNPs were associated with changes in weight and BMI in EA and AA (p ≤ .0032), but none of them was associated with changes in height. Of the eight menarche-timing and BMI-related SNPs, none was associated with changes in height, but three (in or near genes NEGR1, ETV5, and FTO) were associated with more rapid increases in weight and/or BMI in EA (p ≤ .0059). Among the nine menarche-timing and height-related SNPs, four (in or near genes ZBTB38, LOC728666, TBX2, and CABLES) were associated with changes in weight or height in EA and AA (p ≤ .0042).

CONCLUSIONS

Genetic variants related to age at menarche were found to be associated with various growth parameters in healthy adolescents. The identified associations were often race and sex specific.

Associations between menarche-related genetic variants and pubertal growth in male and female adolescents

PURPOSE

Previous studies have identified novel genetic variants associated with age at menarche in females of European descent. The pubertal growth effects of these variants have not been carefully evaluated in non-European descent groups. We aimed to examine the effects of 31 newly identified menarche-related single-nucleotide polymorphisms (SNPs) on growth outcomes in African-American (AA) and European-American (EA) children in a prospective cohort.

METHODS

We analyzed longitudinal data collected from 263 AAs and 338 EAs enrolled between ages 5 and 17 years; the subjects were followed semiannually for an average of 6 years. The associations between the SNPs and growth-related outcomes, including weight, height, and body mass index (BMI), were examined using mixed-effect models.

RESULTS

Longitudinal analyses revealed that 4 (near or in genes VGLL3, PEX2, CA10, and SKOR2) of the 14 menarche-only-related SNPs were associated with changes in weight and BMI in EA and AA (p ≤ .0032), but none of them was associated with changes in height. Of the eight menarche-timing and BMI-related SNPs, none was associated with changes in height, but three (in or near genes NEGR1, ETV5, and FTO) were associated with more rapid increases in weight and/or BMI in EA (p ≤ .0059). Among the nine menarche-timing and height-related SNPs, four (in or near genes ZBTB38, LOC728666, TBX2, and CABLES) were associated with changes in weight or height in EA and AA (p ≤ .0042).

CONCLUSIONS

Genetic variants related to age at menarche were found to be associated with various growth parameters in healthy adolescents. The identified associations were often race and sex specific.

Postnatal weight growth and trihalomethane exposure during pregnancy

BACKGROUND

Impaired postnatal growth after chloroform exposure in utero has been observed in rodents without an effect on birth weight. We aimed to study the relationship between exposure to trihalomethanes (THMs) during pregnancy and postnatal weight growth during infancy.

METHODS

We analysed 2216 mother-child pairs recruited in Gipuzkoa, Sabadell, Valencia (Spain, INMA Project, enrollment: 2003-2008) and Crete (Greece, RHEA Study, enrollment: 2007-2008). Drinking water habits and water-related activities ascertained through personal interviews were combined with THM measurements in drinking water to estimate THM exposure through different exposure routes during pregnancy. Weight measurements during the first year of life were used to fit postnatal weight growth curves from birth to one year and to predict weight at six months. Multiple linear regression was used to evaluate the relationship between six months weight gain and interquartile range (IQR) increase in THM exposure adjusting for confounders.

RESULTS

Average weight gain at six months ranged from 4325 g (Gipuzkoa) to 4668 g (Crete). Median residential THM levels ranged from 1 μg/l (Crete) to 117 μg/l (Sabadell). No significant association was observed overall (-24.4 g [95% CI -78.8, 30.0] for an IQR increase in total residential uptake). A negative relationship was observed in Sabadell (-148 g [95% CI -282, -13.7]) for an IQR increase in ingestion THM uptake.

CONCLUSIONS

No consistent evidence of an association between THM exposure during pregnancy and postnatal growth was observed. The novelty of the hypothesis and the negative trend observed in the region with the highest levels warrants the replication in future studies.

Longitudinal changes in infant body composition: association with childhood obesity

BACKGROUND

Rapid weight gain in infancy has been established as a risk factor for the development of later obesity.

OBJECTIVE

We aimed to investigate the role of changes in infant body composition (assessed via total body electrical conductivity) on the development of overweight/obesity in mid-childhood.

METHODS

Fifty-three term infants were evaluated at birth, three times during infancy and in mid-childhood. Logistic regression was used to determine associations between rates of total weight gain, fat mass gain and lean mass gain during infancy and later overweight/obesity (defined as body mass index [BMI] ≥85th percentile), adjusted for birth weight and parent education.

RESULTS

At follow-up (age 9.0 ± 1.8 years), 30% were overweight/obese. More rapid total weight gain from 0 to 4 months was associated with twofold odds (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.05-3.74, P = 0.04) of overweight/obesity in mid-childhood. From 0 to 8 months, more rapid weight gain was associated with nearly fivefold odds (OR 4.76, 95% CI 1.05-21.5, P = 0.04), and more rapid fat mass gain was associated with eightfold odds (OR 8.03, 95% CI 1.11-58.2, P = 0.04) of later overweight/obesity.

CONCLUSION

This exploratory study suggests that rapid weight gain, especially fat mass gain, in earlier infancy predisposes to mid-childhood overweight/obesity.

Influence of weight gain rate on early life nutritional status and body composition of children

OBJECTIVE

To evaluate the influence of the weight gain rate at 4-6 months on nutritional status and body composition in children between 4 and 7 years of age.

METHODS

Retrospective cohort study, sample of 257 children. Data collection was performed in two stages, with the first relating to retrospective data of weight gain from birth to the first 4-6 months of life in the patient records. Measurements of weight, height, waist circumference, and body composition in children between ages 4 and 7 years were obtained. Nutritional status was assessed by the BMI/age. Control variables, such as pregnancy, breastfeeding, lifestyle, and sociodemographics, were studied. Descriptive analysis and multiple linear regression were performed.

RESULTS

In the nutritional status assessment, the prevalence of overweight observed was 24.9%. After adjusting for control variables, it was found that the increase of the WGR at 4-6 months of age explained the occurrence of higher BMI/age, percentage of total body fat, body fat percentage in the android region, and waist circumference in children between 4 and 7 years of age.

CONCLUSION

The increase of the WGR in the first months of life can lead to the occurrence of higher values of parameters of nutritional status and body composition in later life.

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

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Postnatal growth velocity and overweight in early adolescents: a comparison of rural and urban African boys and girls

Objectives

To compare growth velocity of two African child cohorts and examine the relationship between postnatal growth velocity in infancy/early childhood and the risk of overweight/stunting in early adolescence.

Methods

The study used data from two child cohorts from urban (Birth to Twenty Cohort, South Africa) and rural (Lungwena Child Survival Study, Malawi) African settings. Mixed effect modelling was used to derive growth and peak growth velocities. T-tests were used to compare growth parameters and velocities between the two cohorts. Linear and logistic regression models were used to determine the relationship between growth velocity and early adolescent (ages 9–11 years) body mass index and odds of being overweight.

Results

Children in the BH cohort were significantly taller and heavier than those in the Lungwena cohort, and exhibited faster weight and height growth velocity especially in the first year of life (P < 0.05). No significant association was shown between baseline weight (α_w) and overweight in early adolescence (OR = 1.25, CI = 0.67, 2.34). The weight growth velocity parameter β_w was highly associated with odds of being overweight. Association between overweight in adolescence and weight velocity was stronger in infancy than in early childhood (OR at 3 months = 4.80, CI = 2.49, 9.26; OR at 5 years = 2.39, CI = 1.65, 3.47).

Conclusion

High weight and height growth velocity in infancy, independent of size at birth, is highly associated with overweight in early adolescence. However, the long term effects of rapid growth in infancy may be dependent on a particular population's socio-economic status and level of urbanization. Am. J. Hum. Biol. 26:643–651, 2014. © 2014 The Authors American Journal of Human Biology Published by Wiley Periodicals, Inc.

How growth due to infant nutrition influences obesity and later disease risk

Infant nutrition has a major impact on immediate outcomes and long-term health and later disease risks, such as obesity and related disorders, a phenomenon referred to as 'metabolic programming'. This review discusses the currently postulated hypotheses and mechanisms investigated by the EarlyNutrition project.

CONCLUSION

Rapid weight gain in the first 2 years of life, most notably mediated by diary protein, affects the insulin-like growth factor metabolic pathways. Epigenetic processes seem to play a role.

Individual late-life fecundity plateaus do exist in Drosophila melanogaster and are very common at old age

Several authors have discussed the existence of late-life fecundity plateaus in Drosophila melanogaster. However, all these studies have pooled flies to show such plateaus. Here, we have reanalyzed previously published fecundity results to know whether these plateaus exist at the individual level. We found that these plateaus are observed in ca 20% of females and in more than 50% if only the longer-lived flies are taken into account. We conclude that late-life fecundity plateaus are not a rare phenomenon when considering a whole cohort of flies and are very common in oldest flies.

Child Weight Growth Trajectory and its Determinants in a Sample of Iranian Children from Birth until 2 Years of Age

BACKGROUND

Growth is one of the most important indices in child health. The best and most effective way to investigate child health is measuring the physical growth indices such as weight, height and head circumference. Among these measures, weight growth is the simplest and the most effective way to determine child growth status. Weight trend at a given age is the result of cumulative growth experience, whereas growth velocity represents what is happening at the time.

METHODS

This longitudinal study was conducted among 606 children repeatedly measured from birth until 2 years of age. We used linear mixed model to analyze repeated measures and to determine factors affecting the growth trajectory. LOWESS smooth curve was used to draw velocity curves.

RESULTS

Gender, child rank, birth status and feeding mode had a significant effect on weight trajectory. Boys had higher weight during the study. Infants with exclusive breast feeding had higher weight than other infants. Boys had higher growth velocity up to age 6 month. Breast fed infants had higher growth velocity up to 6 month, but thereafter the velocity was higher in other infants.

CONCLUSIONS

Many of the studies have investigated child growth, but most of them used cross-sectional design. In this study, we used longitudinal method to determine effective factors on weight trend in children from birth until 2-year-old. The effects of perinatal factors on further growth should be considered for prevention of growth disorders and their late complications.

Self-reported maternal parenting style and confidence and infant temperament in a multi-ethnic community: results from the Born in Bradford cohort

Ethnic minority children in the United Kingdom often experience health disadvantage. Parenting influences children's current and future health, but little is known about whether parenting behaviours and mother's perception of her infant vary by ethnicity. Using the Born in Bradford (BiB) birth cohort, which is located in an ethnically diverse and economically deprived UK city, we conducted a cross-sectional analysis of mother's self-reported parenting confidence, self-efficacy, hostility and warmth, and infant temperament at six months of age. We examined responses from women of Pakistani (N = 554) and White British (N = 439) origin. Pakistani mothers reported feeling more confident about their abilities as a parent. Significantly fewer Pakistani women adopted a hostile approach to parenting, an effect that was attenuated after adjustment for socioeconomic status and mental health. Overall, women with more self-efficacious, warm and less hostile parenting styles reported significantly fewer problems with their infant's temperaments. Of women with higher self-efficacy parenting styles, Pakistani mothers were significantly more likely than White British mothers to report more problematic infant temperaments, although absolute differences were small. It is unlikely that the ethnic variation seen in children's cognitive and behavioural outcomes in childhood is attributable to differences in parenting or infant characteristics reported at six months.

Important periods of weight development in childhood: a population-based longitudinal study

Background

Identifying important ages for the development of overweight is essential for optimizing preventive efforts. The purpose of the study was to explore early growth characteristics in children who become overweight or obese at the age of 8 years to identify important ages for the onset of overweight and obesity.

Methods

Data from the Norwegian Child Growth Study in 2010 (N = 3172) were linked with repeated measurements from health records beginning at birth. Weight and height were used to derive the body mass index (BMI) in kg/m². The BMI standard deviation score (SDS) for each participant was estimated at specific target ages, using a piecewise linear mixed effect model.

Results

At 8 years of age, 20.4% of the children were overweight or obese. Already at birth, overweight children had a significantly higher mean BMI SDS than normal weight 8-year-olds (p < .001) and this difference increased in consecutive age groups in infancy and childhood. A relatively large increase in BMI during the first 9 months was identified as important for being overweight at 8 years. BMI SDS at birth was associated with overweight at 8 years of age (OR, 1.8; 1.6–2.0), and with obesity (OR, 1.8; 1.4–2.3). The Odds Ratios for the BMI SDS and change in BMI SDS further increased up to 1 year of age became very high from 2 years of age onwards.

Conclusions

A high birth weight and an increasing BMI SDS during the first 9 months and high BMI from 2 years of age proved important landmarks for the onset of being overweight at 8 years of age. The risks of being overweight at 8 years appear to start very early. Interventions to prevent children becoming overweight should not only start at a very early age but also include the prenatal stage.

Impact of annual body mass index gain on obesity development in Japanese 6-year-old non-obese children

BACKGROUND

Effective timing of preventive intervention for adolescent obesity in non-obese school-aged children remains unclear. The aim of this study was to examine the impact of annual body mass index (BMI) gain on the development of adolescent obesity in 6-year-old non-obese Japanese children.

METHODS

Longitudinal weight and height data were collected annually from 9723 children aged 6-14 years, and individual per-year BMI gains were calculated. The BMI ≥ the 95th percentile for each age and sex defined obesity. In 6-year-old non-obese children, logistic regression analyses were applied to correlate the annual BMI gain at each age with obesity at a final survey.

RESULTS

The 6-year-old non-obese children who became obese at a final survey showed larger annual BMI gains at any age compared with their peers with respect to baseline BMI. Increases in annual BMI gain, even in early school age, raised the risk of adolescent obesity. Categorical analysis also showed that children aged 6-7 years with higher annual BMI gains than 1-SD above the mean had a significant risk for adolescent obesity (OR: 4.39 [95%CI: 2.98-6.46] in boys and 3.83 [95%CI: 2.60-5.63] in girls, respectively).

CONCLUSIONS

A larger annual BMI gain at any school age is a risk for adolescent obesity in 6-year-old non-obese children with no critical period. This suggests the need for earlier and continuous school-based surveillance using annual BMI gain for preventive intervention of adolescent obesity development.

Early-life weight and weight gain as predictors of obesity in Brazilian adolescents

OBJECTIVE

To test whether weight and the weight gain rate during different age periods are associated with being overweight/obese at 10 years of age.

METHODS

A nested case-control study was performed in a clinical historic cohort that was selected based on medical records from the Albert Einstein Hospital Social Program in São Paulo, Brazil. A sample of 378 eutrophic and overweight/obese children was analyzed.

RESULTS

After adjusting for birth weight and gestational age, the likelihood of being overweight/obese at 10 years of age was 4.04-fold greater when progressing from one quartile of weight gain to the immediately superior quartile in the first semester of life and 3.24-fold greater when this occurred from 2-5 years of age. A one-quartile change in weight gain in the first semester was associated with a 0.5 z-score increase in BMI at age 10. A robust independent effect of weight at age 5 confirmed that earlier weight gain was an important predictor.

CONCLUSIONS

The amount of weight gain during the first 6 months of life and between 2 and 5 years of age and weight at age 5 were important predictors of overweight/obesity at 10 years of age.

Is a child's growth pattern early in life related to serum adipokines at the age of 10 years?

BACKGROUND/OBJECTIVES

Growth parameters during infancy and early childhood might predict adipokine levels later in life. This study investigates the association between peak growth velocities, body mass index (BMI) and age at adiposity rebound (AR), with leptin and adiponectin levels at age 10 years.

SUBJECTS/METHODS

Peak height (PHV) and weight (PWV) velocities were calculated from height and weight measurements obtained between birth and age 2 years from 2880 children participating in the GINIplus (German Infant Nutritional Intervention plus environmental and genetic influences on allergy development) and LISAplus (Influences of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood plus Air Pollution and Genetics) birth cohorts. BMI and age at AR were calculated using BMI measurements between age 1.5 and 12 years. Blood samples were collected during a physical examination at age 10. Adiponectin and leptin levels were measured by radioimmunoassay. Linear regression models were fitted after adjustment for potential confounding factors and results are presented per interquartile range increase in the exposure.

RESULTS

Age at AR was negatively associated with leptin in males and females (percent difference β*: -41.71%; 95% confidence interval: (-44.34;-38.96) and β*: -43.22%; (-45.59; -40.75), respectively). For both males and females PWV (β*: 14.23%; (7.60; 21.26) and β*: 18.54%; (10.76; 26.87), respectively) and BMI at AR (β*: 63.08%; (55.04; 71.53) and β*: 67.02%; (59.30; 75.10), respectively) were positively associated with leptin levels. PHV showed a positive effect on leptin in females only (β*: 10.75%; (3.73; 18.25)). Growth parameters were not significantly associated with adiponectin except for age at AR among females (β: 0.75 ng/ml; (0.42; 1.09)) and PWV among males (β: 0.45 ng/ml; (0.11; 0.79)).

CONCLUSION

Growth patterns in early life may be associated with leptin levels at age 10 years.

Multi-level modelling of longitudinal child growth data from the Birth-to-Twenty Cohort: a comparison of growth models

Background: Different structural and non-structural models have been used to describe human growth patterns. However, few studies have compared the fitness of these models in an African transitioning population.

Aim: To find model(s) that best describe the growth pattern from birth to early childhood using mixed effect modelling.

Subjects and methods: The study compared the fitness of four structural (Berkey-Reed, Count, Jenss-Bayley and the adapted Jenss-Bayley) and two non-structural (2nd and 3rd order Polynomial) models. The models were fitted to physical growth data from an urban African setting from birth to 10 years using a multi-level modelling technique. The goodness-of-fit of the models was examined using median and maximum absolute residuals, Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC).

Results: There were variations in how the different models fitted to the data at different measurement occasions. The Jenss-Bayley and the polynomial models did not fit well to growth measurements in the early years, with very high or very low percentage of positive residuals. The Berkey-Reed model fitted consistently well over the study period.

Conclusion: The Berkey-Reed model, previously used and fitted well to infancy growth data, has been shown to also fit well beyond infancy into childhood.

Biomechanical maturation of joint dynamics during early childhood: updated conclusions

Dynamic parameters have been commonly explored to characterize the biomechanical maturation of children's gaits, i.e., age-revealing joint moment and power patterns similar to adult patterns. However, the literature revealed a large disparity of conclusions about maturation depending on the study, which was most likely due to an inappropriate scaling strategy and uncontrolled walking speed. With the first years of independent walking, a large growth in height and a large variability of dimensionless walking speed are observed. Moreover, the dynamic parameters were not well studied during early childhood. In the present study, seventy-five healthy children between 1 and 6 years of age were assessed during gait trials at a self-selected speed. Four hundred and sixty-two gait trials constituting five age groups with comparable dimensionless walking speeds were selected. 3D joint moments and the power of the lower limbs were computed and expressed using a dimensionless scaling strategy (according to body weight, leg length and the acceleration of gravity). Statistical analysis was performed to examine inter-group differences. Based on the current results, we concluded the biomechanical maturation of joint dynamics occurred around an age of 4 years for the ankle and between 6 and 7 years for the knee and the hip. Moreover, age group comparisons seemed more appropriate in young children using both the dimensionless strategy and a similar walking speed. Future investigations will be conducted on an older population (i.e., adding children older than 6 years) to clearly define the status of knee and hip biomechanical maturation.

Diagnostic procedures and treatment of childhood obesity by pediatricians: 'The Dutch approach'

Child Public Health professionals in the Netherlands refer obese children to a pediatrician to check for underlying causes and comorbidity. What happens to these children in terms of diagnostics and treatment when they visit a pediatrician? To get an overview of the diagnostic procedures and treatment methods a questionnaire was developed and sent to all 583 pediatricians in the Netherlands. Data was obtained of 290 pediatricians from 85% of the general hospitals and all (8) academic hospitals. To define childhood obesity Dutch pediatricians most often use the adult Body Mass Index, only 34% use the sex and age specific IOTF-BMI-criteria. 11% of the (non-obese) overweight children visiting a pediatrician have already comorbidities. All pediatricians perform at least weight and height measurements. Waist circumference is measured by only 42%, ninety-five percent measure blood pressure. To treat obese children without comorbidity thirty different intervention programs were reported. A large variation in diagnostics and interventions of childhood obesity exist. Guidelines in pediatric obesity for diagnostics and treatment are urgently needed.

Does parental body mass index status modify the associations among birth weight, early growth and childhood adiposity?

OBJECTIVES

To examine the associations among birth weight, infant growth and childhood adiposity, and to test whether parental weight status modifies these associations.

METHODS

The sample was comprised of 423 participants born at term who were an appropriate size for their gestational age from the Quebec Adipose and Lifestyle Investigation in Youth (QUALITY) study, a cohort of 630 children with a parental history of obesity. Infant growth velocity from zero to two years of age was estimated using slopes from simple linear regression for weight and body mass index (BMI) Z-scores. Child anthropometrics and body composition, and parental BMI were measured from eight to 10 years of age. Associations were modelled using multiple linear regressions.

RESULTS

Increased birth weight and growth velocity independently predicted increased childhood adiposity. Effects of infant growth velocity on later adiposity were stronger with higher maternal BMI but not with higher paternal BMI. Similar interactions with birth weight were not found.

CONCLUSIONS

Early childhood measures of growth and the mother's BMI score should be included in investigations on obesity risk.

Infant feeding patterns over the first year of life: influence of family characteristics

BACKGROUND/OBJECTIVES

Early eating patterns and behaviors can determine later eating habits and food preferences and they have been related to the development of childhood overweight and obesity. We aimed to identify patterns of feeding in the first year of life and to examine their associations with family characteristics.

SUBJECTS/METHODS

Our analysis included 1004 infants from the EDEN mother-child cohort. Feeding practices were assessed through maternal self-report at birth, 4, 8 and 12 months. Principal component analysis was applied to derive patterns from breastfeeding duration, age at complementary food (CF) introduction and type of food used at 1 year. Associations between patterns and family characteristics were analyzed by linear regressions.

RESULTS

The main source of variability in infant feeding was characterized by a pattern labeled 'late CF introduction and use of ready-prepared baby foods'. Older, more educated, primiparous women with high monthly income ranked high on this pattern. The second pattern, labeled 'longer breastfeeding, late CF introduction and use of home-made foods' was the closest to infant feeding guidelines. Mothers ranking high on this pattern were older and more educated. The third pattern, labeled 'use of adults' foods' suggests a less age-specific diet for the infants. Mothers ranking high on this pattern were often younger and multiparous. Recruitment center was related to all patterns.

CONCLUSIONS

Not only maternal education level and age, but also parity and region are important contributors to the variability in patterns. Further studies are needed to describe associations between these patterns and infant growth and later food preferences.

Association between body weight at weaning and remodeling in the subcutaneous adipose tissue of obese adult mice with undernourishment in utero

Rapid growth in infancy considerably increases the risk of obesity and metabolic disorders in adulthood especially among neonates born small. To investigate the mechanism involved, we developed an animal model of undernourishment in utero by maternal caloric restriction, in which the Z scores of body weight at weaning (19.5 days) positively correlated with parameters of obesity, metabolic disorders, and remodeling of subcutaneous adipose tissue, such as numbers of macrophages in adipose tissue, the ratio of inflammatory M1 to anti-inflammatory M2 macrophages, estimated by gene expression of specific antigens, and the relative ratio of small adipocytes less than 30 μm in diameter, on a high-fat diet at 17 weeks of age. To our knowledge, this is the first report of a possible connection between infantile body weight and adipose tissue remodeling in obesity after undernourishment in utero.

Decelerated early growth in infants of overweight and obese mothers

OBJECTIVE

To investigate the relationship between maternal prepregnancy body mass index and early infant growth and body composition.

STUDY DESIGN

Prospective cohort study performed at a university hospital/surrounding community. Ninety-seven nondiabetic mothers with singleton, term, healthy infants completed study visits at 2 weeks and 3 months of age. Before pregnancy, 59 mothers were normal weight, 18 were overweight, and 20 were obese. Infant anthropometrics and body composition via air-displacement plethysmography were measured. Infant feeding information and maternal prepregnancy weight were self-reported. Additional data were obtained via self-report and the medical record. Main outcome measures were change in weight, length, fat-free mass, and fat mass from 2 weeks to 3 months of age. Analysis was done via multivariate linear regression.

RESULTS

At 2 weeks, anthropometrics and body composition did not differ across maternal body mass index groups. At 3 months, infants of overweight or obese mothers had gained less weight (P = .02), grew less in length (P = .01), and gained less fat mass (P = .01). Adjustment for breastfeeding status and regression to the mean via conditional change variables did not alter the results. The results were not altered after adjusting for maternal glucose values from a 50-g glucose challenge and for maternal smoking in a subset including 80% of the women.

CONCLUSIONS

Maternal overweight/obesity is associated with early deceleration in linear growth and adipose tissue accrual; replication of these findings is needed.

Early growth velocities and weight gain plasticity improve linear growth in Peruvian infants

Growth velocity patterns have the potential to signal unhealthy responses to environmental insults with long-term consequences. We aimed to investigate velocities in Peruvian infants (n = 259) in relation to attained anthropometric outcomes at 12 months and to identify determinants of velocities during critical periods of infancy. From 1995 to 1997, a randomised controlled trial of maternal zinc supplementation was conducted in a peri-urban slum area of Lima. Infants were followed monthly through 1 year on a range of anthropometric measures. Three types of velocity variables were studied: (1) incremental velocity (1 months and 3 months); (2) proportional changes (% of total size gained/month); and (3) individual velocity variability [standard deviation (SD) of individual child incremental velocities]. Mean individual child SD of weight velocity was 417 g (±126). In multivariate ordinary least squares regression analyses, growth velocities in month 1 and individual weight velocity variability positively predicted attained length and weight by 12 months. Panel regression by generalised least-squares with random effects of length and weight velocities confirmed the exponentially decelerating pace of growth through infancy and the importance of birth size in driving this trajectory. This study contributes evidence to support the importance of early growth velocities and greater degrees of weight gain plasticity for attained length and weight.

Velocidade de ganho de peso e práticas alimentares no primeiro ano de vida em lactentes de baixo nível socioeconômico

OBJETIVO: Avaliar a velocidade do ganho de peso e sua associação com as práticas alimentares no primeiro ano de vida em crianças de baixo nível socioeconômico. MÉTODOS: Utilizaram-se dados de peso e comprimento ao nascer obtidos dos registros hospitalares e as medidas antropométricas aferidas aos 6 e 12 meses para o cálculo do ganho de peso no primeiro e no segundo semestres de vida. Dados das práticas alimentares das crianças foram obtidos por meio de entrevistas com as mães aos 6 e 12 meses de idade das crianças. RESULTADOS: Avaliaram-se 328 crianças: 184 meninos e 144 meninas. As meninas apresentaram maior ganho de peso em relação ao padrão da Organização Mundial de Saúde nos primeiros 6 meses de vida (4.452kg versus 4.079kg, p=0,000). Dos 6 aos 12 meses, o ganho de peso das crianças avaliadas foi significativamente maior em comparação ao padrão da Organização Mundial de Saúde para os dois sexos (1.929kg versus 1.688kg, p=0,000 para os meninos e 1.900kg versus 1.618kg, p=0,001 para as meninas). As crianças do sexo masculino que receberam aleitamento materno exclusivo por período menor que quatro meses apresentaram maior ganho de peso entre 6 e 12 meses de idade em relação àquelas que receberam somente leite materno por período igual ou superior a quatro meses (M=2,077, DP=0,777 versus M=1,814, DP=0,669 p=0,02). CONCLUSÃO: Este estudo evidenciou que as crianças avaliadas apresentaram ganho de peso excessivo no primeiro ano de vida, e que o aleitamento materno exclusivo apresentou papel protetor.

Bases biológicas e evidências epidemiológicas da contribuição do crescimento fetal e pós-natal na composição corporal: uma revisão

OBJETIVOS: apresentar as bases biológicas e evidências epidemiológicas do crescimento fetal e pós-natal relacionadas ao tamanho e composição corporal. MÉTODOS: a busca de artigos publicados nos últimos 15 anos foi realizada nas bases de dados Lilacs, SciELO, Medline através dos descritores: crescimento, restrição do crescimento fetal, baixo peso ao nascer, aceleração compensatória do crescimento, composição corporal, índice de massa corporal e hormônios. Os estudos foram selecionados de acordo com a pertinência às evidências a serem analisadas. RESULTADOS: os artigos apontam para a influência da restrição do crescimento intraútero na supressão da termogênese e regulação hormonal, que por sua vez interferem no ganho de peso após o nascimento, e explicam como ambos os processos, restrição do crescimento fetal e rápido ganho de peso pós-natal, influenciam as medidas corporais em fases posteriores da vida, com consequências que poderão afetar gerações. CONCLUSÕES: o crescimento fetal influencia o padrão de crescimento pós-natal devido a diversos fatores relacionados à regulação hormonal, porém existe ainda uma lacuna sobre a contribuição da somação entre crescimento fetal e pós-natal no tamanho e composição corporal em fases posteriores da vida.

BMI development of normal weight and overweight children in the PIAMA study

BACKGROUND

There is evidence that rapid weight gain during the first year of life is associated with overweight later in life. However, results from studies exploring other critical periods for the development of overweight are inconsistent.

OBJECTIVE

The objective was to investigate BMI development to assess at what ages essential differences between normal weight and overweight children occur, and to assess which age intervals the most strongly influence the risk of overweight at 8 years of age.

METHODS

Longitudinal weight and height data were collected by annual questionnaires in a population of 3963 children participating in the PIAMA birth cohort study. BMI and BMI standard deviation scores (SDS) were calculated for every year from birth until 8 years of age. BMI, BMI SDS and BMI SDS change in each 1-year-age interval were compared between children with and without overweight at 8 years of age, using t-tests, logistic regression analysis and the analysis of response profiles method.

RESULTS

At 8 years of age, 10.5% of the children were overweight. Already at the age of 1 year, these children had a significantly higher mean BMI SDS than normal weight 8-year-olds, (0.53 vs 0.04). In each 1-year-age interval the change in BMI SDS was significantly associated with overweight at 8 years with odds ratios increasing from 1.14 (95% CI 1.04-1.24) per 1 SDS increase at 0-1 year to 2.40 (95% CI 2.09-2.76) at 7-8 years.

CONCLUSION

At every age, starting already in the first year of life, a rapid increase in BMI SDS was significantly associated with overweight risk at the age of 8 years. There was no evidence for a specific critical period for the development of overweight. Prevention of overweight should start early in life and be continued with age-specific interventions throughout childhood.

Next steps in obesity prevention: altering early life systems to support healthy parents, infants, and toddlers

There is an urgent need for effective, sustainable child obesity prevention strategies. Progress toward this goal requires strengthening current approaches to add a component that addresses pregnancy onward. Altering early-life systems that promote intergenerational transmission of obesity holds promise for interrupting the continuing cycle of the obesity epidemic. A 2011 Institute of Medicine (IOM) report emphasizes the need for interventions early in life to prevent obesity. A 2010 IOM report called for addressing gaps in existing obesity research evidence by using a systems perspective, simultaneously addressing interacting obesity promoting factors in multiple sectors and at multiple societal levels. A review of evidence from basic science, prevention, and systems research supports an approach that (1) begins at the earliest stages of development, and (2) uses a systems framework to simultaneously implement health behavior and environmental changes in communities.

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

OBJECTIVES

People of low socioeconomic status are shorter than those of high socioeconomic status. The first two years of life being critical for height development, we hypothesized that a low socioeconomic status is associated with a slower linear growth in early childhood. We studied maternal educational level (high, mid-high, mid-low, and low) as a measure of socioeconomic status and its association with repeatedly measured height in children aged 0-2 years, and also examined to what extent known determinants of postnatal growth contribute to this association.

METHODS

This study was based on data from 2972 mothers with a Dutch ethnicity, and their children participating in The Generation R Study, a population-based cohort study in Rotterdam, The Netherlands (participation rate 61%). All children were born between April 2002 and January 2006. Height was measured at 2 months (mid-90% range 1.0-3.9), 6 months (mid-90% range 5.6-11.4), 14 months (mid-90% range 13.7-17.9) and 25 months of age (mid-90% range 23.6-29.6).

RESULTS

At 2 months, children in the lowest educational subgroup were shorter than those in the highest (difference: -0.87 cm; 95% CI: -1.16, -0.58). Between 1 and 18 months, they grew faster than their counterparts. By 14 months, children in the lowest educational subgroup were taller than those in the highest (difference at 14 months: 0.40 cm; 95% CI: 0.08,0.72). Adjustment for other determinants of postnatal growth did not explain the taller height. On the contrary, the differences became even larger (difference at 14 months: 0.61 cm; 95% CI: 0.26,0.95; and at 25 months: 1.00 cm; 95% CI: 0.57,1.43)

CONCLUSIONS

Compared with children of high socioeconomic status, those of low socioeconomic status show an accelerated linear growth until the 18th month of life, leading to an overcompensation of their initial height deficit. The long-term consequences of these findings remain unclear and require further study.

Need for early interventions in the prevention of pediatric overweight: a review and upcoming directions

Childhood obesity is currently one of the most prevailing and challenging public health issues among industrialized countries and of international priority. The global prevalence of obesity poses such a serious concern that the World Health Organization (WHO) has described it as a "global epidemic." Recent literature suggests that the genesis of the problem occurs in the first years of life as feeding patterns, dietary habits, and parental feeding practices are established. Obesity prevention evidence points to specific dietary factors, such as the promotion of breastfeeding and appropriate introduction of nutritious complementary foods, but also calls for attention to parental feeding practices, awareness of appropriate responses to infant hunger and satiety cues, physical activity/inactivity behaviors, infant sleep duration, and family meals. Interventions that begin at birth, targeting multiple factors related to healthy growth, have not been adequately studied. Due to the overwhelming importance and global significance of excess weight within pediatric populations, this narrative review was undertaken to summarize factors associated with overweight and obesity among infants and toddlers, with focus on potentially modifiable risk factors beginning at birth, and to address the need for early intervention prevention.

Postnatal Growth Patterns in a Chilean Cohort: The Role of SES and Family Environment

Objective. This study examined how family environmental characteristics served as mediators in the relationship between socioeconomic conditions and infant growth in a cohort of Chilean infants. Methods. We studied 999 infants, born between 1991 and 1996, from a longitudinal cohort which began as an iron deficiency anemia preventive trial. SES (Graffar Index), the Life Experiences Survey, and the Home Observation for Measurement of the Environment (HOME) were assessed in infancy. Using path analysis, we assessed the relationships between the social factors, home environment, and infant growth. Results. During the first year, weight and length gain averaged 540 grams/month and 6.5 cm/month, respectively. In the path analysis model for weight gain, higher SES and a better physical environment were positively related to higher maternal warmth, which in turn was associated with higher average weight gain. Higher SES was directly related to higher average length gain. Conclusions. In our cohort, a direct relationship between SES and length gain developed during infancy. Higher SES was indirectly related to infant weight gain through the home environment and maternal warmth. As the fastest growing infants are at risk for later obesity, new strategies are needed to encourage optimal rather than maximal growth.

Evolution of obesity in a low birth weight cohort

OBJECTIVE

The objective of this study was to determine the evolution of obesity status (OS) in a longitudinal cohort of low birth weight preterm (LBWPT) infants to an age of 8 years, and to determine whether rapid weight gain in the first year of life independently predicts 8-year OS.

STUDY DESIGN

In total, 985 infants (birth weight ≤2500 g, gestation age ≤37 weeks) were recruited from the nursery in an eight-site intervention research program and were evaluated at an age of 3, 5, 6.5 and 8 years. Weight and height were measured by standard protocol at each visit and body mass index was calculated. Obesity status is ≥95% for age and sex. Multiple logistic analyses were performed on 8-year OS with predictor variables including infant race, gender, small for gestational age status, birth weight category, neonatal health index, treatment group and first-year weight gain; maternal education and weight status before conception; and HOME Inventory.

RESULT

Overall, 2.3% were OS at an age of 3 years, 6.1% at an age of 5 years, 7.7% at age 6.5 years and 8.7% at an age 8 years. OS varied by birth weight category at each visit. The infants born ≤1500 g had the lowest prevalence of OS at each age. In the logistic regression, maternal race (Hispanic) (adjusted odds ratio=2.8, confidence interval=1.2 to 6.8), maternal obese status (adjusted odds ratio 3.4, confidence interval=1.5 to 7.8) and first-year weight gain (adjusted odds ratio=2.7, confidence interval=1.9 to 3.9), significantly predicted 8-year OS.

CONCLUSION

OS is common in LBWPT infants during childhood, and prevalence varies by birth weight category. High weight gain in the first year of life is an important predictor of the development of OS in LBWPT children.

Analysis of baseline parameters in the HALT polycystic kidney disease trials

HALT PKD consists of two ongoing randomized trials with the largest cohort of systematically studied patients with autosomal dominant polycystic kidney disease to date. Study A will compare combined treatment with an angiotensin-converting inhibitor and receptor blocker to inhibitor alone and standard compared with low blood pressure targets in 558 early-stage disease patients with an eGFR over 60 ml/min per 1.73 m(2). Study B will compare inhibitor-blocker treatment to the inhibitor alone in 486 late-stage patients with eGFR 25-60 ml/min per 1.73 m(2). We used correlation and multiple regression cross-sectional analyses to determine associations of baseline parameters with total kidney, liver, or liver cyst volumes measured by MRI in Study A and eGFR in both studies. Lower eGFR and higher natural log-transformed urine albumin excretion were independently associated with a larger natural log-transformed total kidney volume adjusted for height (ln(HtTKV)). Higher body surface area was independently associated with a higher ln(HtTKV) and lower eGFR. Men had larger height-adjusted total kidney volume and smaller liver cyst volumes than women. A weak correlation was found between the ln(HtTKV) and natural log-transformed total liver volume adjusted for height or natural log liver cyst volume in women only. Women had higher urine aldosterone excretion and lower plasma potassium. Thus, our analysis (1) confirms a strong association between renal volume and functional parameters, (2) shows that gender and other factors differentially affect the development of polycystic disease in the kidney and liver, and (3) suggests an association between anthropomorphic measures reflecting prenatal and/or postnatal growth and disease severity.

Maternal behaviors during pregnancy impact offspring obesity risk

This study investigated the effects of maternal changes during pregnancy in diet, exercise, and psychosocial factors on offspring weight parameters at birth and 6 months. In overweight/obese (OW/OB; n = 132) mothers, greater % kcal from sweets early in pregnancy was the strongest, independent predictor of higher weight for age (WFA) (beta = 0.19; P = 0.004), higher odds of macrosomia (OR = 1.1 (1.0-1.2); P = 0.004) and WFA >90th percentile at birth (OR = 1.2 (1.1-1.3); P = 0.002) and higher WFA at 6 months (beta = 0.30; P = 0.002). In normal weight (n = 153) mothers, higher intake of soft drinks was the strongest predictor of higher offspring WFA at birth (beta = 0.16; P = 0.04) but not at 6 months. Prenatal physical activity, depressive symptoms, and sleep-related variables did not significantly predict offspring weight outcomes. Mothers' eating behaviors during pregnancy, especially intake of sweets in OW/OB mothers, may have a lasting effect on child weight.

Higher cord C-peptide concentrations are associated with slower growth rate in the 1st year of life in girls but not in boys

OBJECTIVE

To understand the relationships between maternal glycemia during pregnancy and prenatal and early postnatal growth by evaluating cord C-peptide and IGF-I as mediating biomarkers in boys and girls separately.

RESEARCH DESIGN AND METHODS

We evaluated 342 neonates within the EDEN mother-child cohort study born to mothers without diabetes diagnosis before pregnancy. We measured maternal glycemia at 24-28 weeks of gestation and neonates' cord blood C-peptide (used as a proxy for fetal insulin) and IGF-I at birth. Reported maternal prepregnancy BMI and all measured infant weights and lengths in the 1st year were recorded. Growth modeling was used to obtain an individual growth curve for each infant in the 1st year. Path models, a type of structural equation modeling, were used for statistical analysis. Path analysis is a multivariate method associated with a graphical display that allows evaluation of mediating factors and distinguishes direct, indirect, and total effects.

RESULTS

Cord C-peptide at birth was positively correlated with maternal prepregnancy BMI and maternal glycemia and was higher in girls. In a path model that represented prenatal growth, there was no significant direct effect of maternal glycemia on birth weight, but the effect of maternal glycemia on birth weight was mediated by fetal insulin and IGF-I in both girls and boys. However, in girls only, higher concentrations of cord C-peptide (but not cord IGF-I or maternal glucose) were associated with slower weight growth in the first 3 months of life.

CONCLUSIONS

Our study underlines the role of the fetal insulin-IGF-I axis in the relationship between maternal glycemia during pregnancy and birth weight. We also show for the first time that high insulin concentration in female fetuses is associated with slower early postnatal growth. This slow, early growth pattern may be programmed by fetal hyperinsulinemia, and girls may be more susceptible than boys to its consequences.

Obesity and energy balance: is the tail wagging the dog?

The scientific study of obesity has been dominated throughout the twentieth century by the concept of energy balance. This conceptual approach, based on fundamental thermodynamic principles, states that energy cannot be destroyed, and can only be gained, lost or stored by an organism. Its application in obesity research has emphasised excessive appetite (gluttony), or insufficient physical activity (sloth), as the primary determinants of excess weight gain, reflected in current guidelines for obesity prevention and treatment. This model cannot explain why weight accumulates persistently rather than reaching a plateau, and underplays the effect of variability in dietary constituents on energy and intermediary metabolism. An alternative model emphasises the capacity of fructose and fructose-derived sweeteners (sucrose, high-fructose corn syrup) to perturb cellular metabolism via modification of the adenosine monophosphate (AMP)/adenosine triphosphate (ATP) ratio, activation of AMP kinase and compensatory mechanisms, which favour adipose tissue accretion and increased appetite while depressing physical activity. This conceptual model implicates chronic hyperinsulinaemia in the presence of a paradoxical state of 'cellular starvation' as a key driver of the metabolic modifications inducing chronic weight gain. We combine evidence from in vitro and in vivo experiments to formulate a perspective on obesity aetiology that emphasises metabolic flexibility and dietary composition rather than energy balance. Using this model, we question the direction of causation of reported associations between obesity and sleep duration or childhood growth. Our perspective generates new hypotheses, which can be tested to improve our understanding of the current obesity epidemic, and to identify novel strategies for prevention or treatment.

The role of infant feeding practices in the explanation for ethnic differences in infant growth: the Amsterdam Born Children and their Development study

Rapid early growth in infants may influence overweight and CVD in later life. Both rapid growth and these disease outcomes disproportionately affect some ethnic minorities. We determined ethnic differences in growth rate (Δ standard deviation scores, ΔSDS) during the first 6 months of life and assessed the explanatory role of infant feeding. Data were derived from a multiethnic cohort for the Amsterdam Born Children and their Development study (The Netherlands). Growth data (weight and length) of 2998 term-born singleton infants with no fetal growth restriction were available for five ethnic populations: Dutch (n 1619), African descent (n 174), Turkish (n 167), Moroccan (n 232) and other non-Dutch (n 806). ΔSDS for weight, length and weight-for-length between 4 weeks and 6 months were defined using internal references. Infant feeding pattern (breast-feeding duration, introduction of formula feeding and complementary feeding) in relation to ethnic differences in growth rate was examined by multivariate linear regression. Results showed that the growth rate was higher in almost all ethnic minorities, with β between 0·07 and 0·41 for ΔSDS weight and between 0·12 and 0·42 for ΔSDS length, compared with ethnic Dutch infants. ΔSDS weight-for-length was similar across groups, except for Moroccan infants (β 0·25, P < 0·05) after correction for confounders. In general, exclusive breast-feeding for 4 months was associated with slower growth for all three growth measures. Feeding factors explained, to a small degree, the higher weight and length gain in African descent infants, but not the higher ΔSDS weight-for-length in the Moroccan population. More research is needed to elucidate the underlying mechanisms of the high infant growth rate in Turkish and Moroccan infants.

Diagnosis of a trend towards obesity in preschool children: a longitudinal study

The study was planned to determine identifiable starting points of a trend towards obesity and the influence of variables in preschool children aged 0 to 6 years. In this longitudinal follow-up study, 102 children were enrolled. Anthropometric measurements such as weight-height centiles (specific for gender and age group), weight-height growth velocities, and body mass indices were taken annually and compared within each group from birth to 6 years. Family history and lifestyle variables were also recorded and compared. Our study has shown that gender does not affect the trend towards obesity. In obese children, the earliest sign of a trend was the rapid increase of weight and weight gain velocity after 6 months. There were upward trends in the BMI values indicating obesity at 1 year of age in boys and at 6 months of age in girls. The height was higher in obese children than in non-obese ones after 4 years of age. Paternal obesity and having an obese sibling were significant risk factors for obesity. In conclusion, 6 months are considered to be the most critical periods for evaluating the development of obesity in childhood. The efforts for preventing obesity should be initiated at 6 months of age.

Genetic and environmental influences on infant growth: prospective analysis of the Gemini twin birth cohort

OBJECTIVE

Infancy is a critical period during which rapid growth potentially programs future disease risk. Identifying the modifiable determinants of growth is therefore important. To capture the complexity of infant growth, we modeled growth trajectories from birth to six months in order to compare the genetic and environmental influences on growth trajectory parameters with single time-point measures at birth, three and six months of age.

METHODS

Data were from Gemini, a population sample of 2402 UK families with twins. An average 10 weight measurements per child made by health professionals were available over the first six months. Weights at birth, three and six months were identified. Longitudinal growth trajectories were modeled using SITAR utilizing all available weight measures for each child. SITAR generates three parameters: size (characterizing mean weight throughout infancy), tempo (indicating age at peak weight velocity (PWV)), and velocity (reflecting the size of PWV). Genetic and environmental influences were estimated using quantitative genetic analysis.

RESULTS

In line with previous studies, heritability of weight at birth and three months was low (38%), but it was higher at six months (62%). Heritability of the growth trajectory parameters was high for size (69%) and velocity (57%), but low (35%) for tempo. Common environmental influences predominated for tempo (42%).

CONCLUSION

Modeled growth parameters using SITAR indicated that size and velocity were primarily under genetic influence but tempo was predominantly environmentally determined. These results emphasize the importance of identifying specific modifiable environmental determinants of the timing of peak infant growth.

Velocidade de ganho de peso nos primeiros anos de vida e excesso de peso entre 5-11 anos de idade, Salvador, Bahia, Brasil

Crianças com sobrepeso estão mais propensas a se tornarem adultos com sobrepeso ou obesos, sendo a prevenção mais eficaz a intervenção em fases precoces da vida. Analisou-se a associação entre ganho de peso nos primeiros anos de vida e sobrepeso/obesidade em 1.056 crianças menores de 11 anos de idade. Foram coletadas informações relacionadas ao estilo de vida, saneamento, condições socioeconômicas, peso ao nascer e aleitamento materno. O ganho de peso do nascimento até diferentes intervalos (até 12 meses, > 12 a 18, > 18 a 24, e > 24 a 60 meses) foi considerado de forma contínua em escores-z. Foi considerado excesso de peso o índice de massa corporal (IMC) maior ou igual a +1 escore-z, usando referências da Organização Mundial da Saúde (OMS) de 2006 e 2007. Adotou-se a regressão linear e Poisson multivariada. A velocidade do ganho ponderal mostrou-se associada ao IMC, observando-se duas vezes mais sobrepeso/obesidade a cada incremento de uma unidade no desvio-padrão da velocidade do ganho ponderal para o intervalo de 24 e 60 meses (RR = 2,08; IC95%: 1,87-2,32). Encontrou-se associação entre o rápido ganho de peso em todos os intervalos de idade e a ocorrência de sobrepeso/obesidade anos mais tarde.

Validation of quantitative magnetic resonance body composition analysis for infants using piglet model

A study was conducted to validate the use of a quantitative magnetic resonance (QMR) device for measuring the body composition of infants and neonates weighing < 12 kg using the pig as a model. A total of 25 piglets weighing between 2 and 12 kg were studied. Body composition was assessed by QMR, dual-energy x-ray absorptiometry (DXA), and whole-body chemical analysis (CA) of carcass for lipid and water content. The precision, mean and SD of repeated measurements, of QMR to estimate fat mass (FM), lean mass (LM), and total body water (TBW) for five consecutive scans with reposition was 12.5, 32.0, and 36.0 g, respectively. QMR measures of FM, LM, and TBW were highly and significantly correlated with CA of carcass. In terms of accuracy, mean difference between QMR and CA (percent of mean value for CA), QMR overestimated FM by 40 g (4.7%), overestimated LM by 114.9 g (2.1%), and underestimated TBW by 134.6 g (3.1%). This study concludes that QMR provides precise and accurate measures of FM, LM, and TBW in piglet weighing up to 12 kg. These results suggest that QMR can provide valuable body composition data in longitudinal studies in infants.

Effects of pre-pregnancy body mass index and gestational weight gain on infant anthropometric outcomes

OBJECTIVE

To determine whether pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) influence infant postnatal growth.

STUDY DESIGN

Participants were from the Pregnancy, Infection, and Nutrition study, a prospective pregnancy cohort. Term infants with weight or length measurements at approximately 6 months were included (n = 363). Multivariable regression estimated associations for weight-for-age (WAZ), length-for-age (LAZ), and weight-for-length z-scores (WLZ) and rapid infant weight gain with categorical maternal exposures defined with the 2009 Institute of Medicine recommendations.

RESULTS

Pre-pregnancy overweight and obesity were associated with higher WAZ (linear regression coefficient [β], 0.32; 95% CI, 0.04-0.61) and WLZ (β, 0.39; 95% CI, 0.02-0.76), respectively. Pre-pregnancy BMI was not associated with LAZ. Excessive GWG was associated with higher WAZ (β, 0.39; 95% CI, 0.15-0.62) and LAZ (β, 0.34; 95% CI, 0.12-0.56). Excessive GWG ≥ 200% of recommended amount was associated with higher WAZ (β, 0.68; 95% CI, 0.28-1.07), LAZ (β, 0.45; 95% CI, 0.06-0.83), and WLZ (β, 0.43; 95% CI, 0.04-0.82). Risk of rapid weight gain increased across maternal exposure categories; however, none of the estimates were significant.

CONCLUSIONS

Pre-pregnancy BMI and GWG are modifiable intrauterine exposures that influence infant postnatal anthropometric outcomes. Further investigation with infant body composition measurements is warranted.

Prenatal organochlorine compound exposure, rapid weight gain, and overweight in infancy

BACKGROUND

Although it has been hypothesized that fetal exposure to endocrine-disrupting chemicals may increase obesity risk, empirical data are limited, and it is uncertain how early in life any effects may begin.

OBJECTIVES

We explored whether prenatal exposure to several organochlorine compounds (OCs) is associated with rapid growth in the first 6 months of life and body mass index (BMI) later in infancy.

METHODS

Data come from the INMA (Infancia y Medio-Ambiente) Child and Environment birth cohort in Spain, which recruited 657 women in early pregnancy. Rapid growth during the first 6 months was defined as a change in weight-for-age z-scores > 0.67, and elevated BMI at 14 months, as a z-score ≥ the 85th percentile. Generalized linear models were used to estimate the risk of rapid growth or elevated BMI associated with 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), hexachlorobenzene, β-hexachlorohexane, and polychlorinated biphenyls in first-trimester maternal serum.

RESULTS

After multivariable adjustment including other OCs, DDE exposure above the first quartile was associated with doubling of the risk of rapid growth among children of normal-weight (BMI < 25 kg/m2), but not overweight, mothers. DDE was also associated with elevated BMI at 14 months (relative risk per unit increase in log DDE = 1.50; 95% confidence interval, 1.11-2.03). Other OCs were not associated with rapid growth or elevated BMI after adjustment.

CONCLUSIONS

In this study we found prenatal DDE exposure to be associated with rapid weight gain in the first 6 months and elevated BMI later in infancy, among infants of normal-weight mothers. More research exploring the potential role of chemical exposures in early-onset obesity is needed.