Associations of size at birth and dual-energy X-ray absorptiometry measures of lean and fat mass at 9 to 10 y of age

Associations of Maternal Educational Level, Proximity to Green Space During Pregnancy, and Gestational Diabetes With Body Mass Index From Infancy to Early Adulthood: A Proof-of-Concept Federated Analysis in 18 Birth Cohorts

International sharing of cohort data for research is important and challenging. We explored the feasibility of multicohort federated analyses by examining associations between 3 pregnancy exposures (maternal education, exposure to green vegetation, and gestational diabetes) and offspring body mass index (BMI) from infancy to age 17 years. We used data from 18 cohorts (n = 206,180 mother-child pairs) from the EU Child Cohort Network and derived BMI at ages 0-1, 2-3, 4-7, 8-13, and 14-17 years. Associations were estimated using linear regression via 1-stage individual participant data meta-analysis using DataSHIELD. Associations between lower maternal education and higher child BMI emerged from age 4 and increased with age (difference in BMI z score comparing low with high education, at age 2-3 years = 0.03 (95% confidence interval (CI): 0.00, 0.05), at 4-7 years = 0.16 (95% CI: 0.14, 0.17), and at 8-13 years = 0.24 (95% CI: 0.22, 0.26)). Gestational diabetes was positively associated with BMI from age 8 years (BMI z score difference = 0.18, 95% CI: 0.12, 0.25) but not at younger ages; however, associations attenuated towards the null when restricted to cohorts that measured gestational diabetes via universal screening. Exposure to green vegetation was weakly associated with higher BMI up to age 1 year but not at older ages. Opportunities of cross-cohort federated analyses are discussed.

Infant body composition at 6 and 24 months: what are the driving factors?

BACKGROUND/OBJECTIVE

Available evidence on infant body composition is limited. This study aimed to investigate factors associated with body composition at 6 and 24 months.

SUBJECTS/METHODS

Multicenter study with data from a 0 to 6-mo cohort (Australia, India and South Africa) and a 3 to 24-mo cohort (Brazil, Pakistan, South Africa, and Sri Lanka). For the 0-6-mo cohort, body composition was assessed by air-displacement plethysmography (ADP) and for the 3-24-month cohort by the deuterium dilution (DD) technique. Fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI) were calculated. Independent variables comprised the Gini index of the country, maternal and infant characteristics, and breastfeeding pattern at 3 months. For the 3-24-mo cohort, breastfeeding, and minimum dietary diversity (MDD) at 12 months were also included. Crude and adjusted analyses stratified by sex were conducted by multilevel modelling using mixed models.

RESULTS

At 6 months, every 1 kg increase in birth weight was associated with an increase of 0.716 kg in FFM and 0.582 kg/m2 in FFMI in girls, whereas in boys, the increase was of 0.277 kg in FFM. At 24 months, compared to those weaned before 12 months, girls still breastfed at 12 months presented a decrease of 0.225 kg in FM, 0.645 kg in FFM and 0.459 kg/m2 in FFMI, and in boys the decreases were of 0.467 kg in FM, 0.603 kg in FFM and 0.628 kg/m2 in FFMI.

CONCLUSION

Birth weight and breastfeeding are independent predictors of body composition in early life, irrespective of sex.

Associations of weight and body composition at birth with body composition and cardiometabolic markers in children aged 10 y: the Ethiopian infant anthropometry and body composition birth cohort study

BACKGROUND

Although birth weight (BW) has been associated with later cardiovascular disease and type 2 diabetes, the role of birth fat mass (BFM) and birth fat-free mass (BFFM) on cardiometabolic health is unclear.

OBJECTIVES

To examine associations of BW, BFM, and BFFM with later anthropometry, body composition, abdominal fat, and cardiometabolic markers.

METHODS

Birth cohort data on standardized exposure variables (BW, BFM, and BFFM) and follow-up information at age 10 y on anthropometry, body composition, abdominal fat, and cardiometabolic markers were included. A linear regression analysis was used to assess associations of exposures with outcome variables, adjusting for maternal and child characteristics at birth and current body size in separate models.

RESULTS

Among 353 children, mean (SD) age was 9.8 (1.0) y, and 51.5% were boys. In the fully adjusted model, 1-SD higher BW and BFFM were associated with 0.81 cm (95% CI: 0.21, 1.41 cm) and 1.25 cm (95% CI: 0.64, 1.85 cm) greater height at 10 y, respectively. The 1-SD higher BW and BFM were associated with 0.32 kg/m2 (95% CI: 0.14, 0.51 kg/m2) and 0.42 kg/m2 (95% CI: 0.25, 0.59 kg/m2) greater fat mass index at 10 y, respectively. In addition, 1-SD higher BW and BFFM were associated with 0.22 kg/m2 (95% CI: 0.09, 0.34 kg/m2) greater FFM index, whereas a 1-SD greater BFM was associated with a 0.05 cm greater subcutaneous adipose tissue (95% CI: 0.01, 0.11 cm). Furthermore, 1-SD higher BW and BFFM were associated with 10.3% (95% CI: 1.4%, 20.0%) and 8.3% (95% CI: -0.5%, 17.9%) greater insulin, respectively. Similarly, 1-SD higher BW and BFFM were associated with 10.0% (95% CI: 0.9%, 20.0%) and 8.5% (95% CI: -0.6%, 18.5%) greater homeostasis model assessment of insulin resistance, respectively.

CONCLUSIONS

BW and BFFM rather than BFM are predictors of height and FFM index at 10 y. Children with higher BW and BFFM showed higher insulin concentrations and homeostasis model assessment of insulin resistance at 10 y of age. This trial was registered at ISRCTN as ISRCTN46718296.

Is small for gestational age status independently correlated with body composition during childhood?

This study aims to examine if small for gestation age (SGA) status is correlated with alterations in body composition at prepuberty, independently of other factors, comparing SGA-born children with appropriate for gestational age (AGA)-born children. We examined anthropometrics, waist circumference, body mass index (BMI), six skinfold thickness, and body composition using the method of bioelectrical impedance in 636 children aged 7 to 10 years. We also considered age, gender, birth mode, mother's age, prepregnancy weight, weight gain during pregnancy, social status, parental BMI, type of feeding, and daily exercise. We examined 636 children at a mean age of 9 years: 106 SGA-born and 530 AGA-born children. SGA as compared to AGA-born children had a lower BMI z-score (0.26 ± 0.89 kg/cm² vs 0.46 ± 0.84 kg/cm², p < 0.050) and a lower lean mass, although that was not statistically significant (24.0 ± 6.6 kg vs 25.6 ± 6.4 kg, p < 0.100). SGA-born children presented no difference in waist circumference or fat mass in comparison to children born AGA. Logistic regression analysis revealed a strong independent negative association between SGA status and BMI (beta =  - 2.33, OR = 0.70 p = 0.019) and SGA status and lean mass (beta =  - 2.43, OR = 0.95 p = 0.010).  Conclusion: Our findings suggest that SGA-born children had a lower BMI as compared to AGA-born subjects, whereas SGA status was negatively associated with BMI and lean mass. What is Known: • Deviant birth weight for gestation has been associated with an increased risk of childhood adiposity. • Evidence remains scarce on whether small for gestational age status affects body composition and obesity later in childhood. What is New: • Among school-aged children, small for gestational age subjects had a lower body mass index as compared to appropriate for gestational age counterparts, whereas small for gestational age status was negatively associated with body mass index and lean mass. • A meticulous observation is needed during childhood in children born with deviant birth weight.

Prenatal exposure to mixtures of persistent environmental chemicals and fetal growth outcomes in Western Australia

BACKGROUND

Environmental chemicals have been implicated in the etiology of impaired fetal growth. However, few studies have assessed the effects of chemical mixtures or considered the possibility of non-monotonic exposure-response relationships for chemicals that act through the endocrine system.

METHODS

We assessed exposure to polybrominated diphenyl ethers, organochlorine pesticides, metals, and perfluorinated alkyl substances in blood and urine samples collected approximately two weeks prior to delivery in 166 non-smoking pregnant women, and subsequent birth weight, length, and head circumference of neonates who were part of the Australian Maternal Exposures to Toxic Substances (AMETS) study. We used Bayesian structured additive regression models with spike-slab priors to estimate mixture effects, identify important exposures, and model non-linearity in exposure-response relationships.

RESULTS

Mixtures of polybrominated diphenyl ethers, organochlorine pesticides, metals, and perfluorinated alkyl substances were not associated with fetal growth outcomes. Estimated change in fetal growth outcomes for an increase in exposure from the 25th to 75th percentile suggested no meaningful associations; the strongest evidence was for a small inverse association between birth weight and cesium exposure measured in whole blood (-124 g, 90% credible interval: -240 to -3 g). We identified several chemicals that may be associated with fetal growth non-linearly; however, 90% credible intervals contained small values consistent with no meaningful association.

CONCLUSIONS

Using a Bayesian penalized regression method, we assessed the shapes of exposure-response relationships, controlled for confounding by co-exposure, and estimated the single and combined effects of a large mixture of correlated environmental chemicals on fetal growth. Our findings, based on a small sample of mother-neonate pairs, suggest that mixtures of persistent chemicals are not associated with birth weight, length, and head circumference. The potential for non-monotonic relationships between environmental chemicals and fetal growth outcomes warrants further study.

Anemic hypoxemia reduces myoblast proliferation and muscle growth in late-gestation fetal sheep

Fetal skeletal muscle growth requires myoblast proliferation, differentiation, and fusion into myofibers in addition to protein accretion for fiber hypertrophy. Oxygen is an important regulator of this process. Therefore, we hypothesized that fetal anemic hypoxemia would inhibit skeletal muscle growth. Studies were performed in late-gestation fetal sheep that were bled to anemic and therefore hypoxemic conditions beginning at ∼125 days of gestation (term = 148 days) for 9 ± 0 days (n = 19) and compared with control fetuses (n = 16). A metabolic study was performed on gestational day ∼134 to measure fetal protein kinetic rates. Myoblast proliferation and myofiber area were determined in biceps femoris (BF), tibialis anterior (TA), and flexor digitorum superficialis (FDS) muscles. mRNA expression of muscle regulatory factors was determined in BF. Fetal arterial hematocrit and oxygen content were 28% and 52% lower, respectively, in anemic fetuses. Fetal weight and whole body protein synthesis, breakdown, and accretion rates were not different between groups. Hindlimb length, however, was 7% shorter in anemic fetuses. TA and FDS muscles weighed less, and FDS myofiber area was smaller in anemic fetuses compared with controls. The percentage of Pax7⁺ myoblasts that expressed Ki67 was lower in BF and tended to be lower in FDS from anemic fetuses indicating reduced myoblast proliferation. There was less MYOD and MYF6 mRNA expression in anemic versus control BF consistent with reduced myoblast differentiation. These results indicate that fetal anemic hypoxemia reduced muscle growth. We speculate that fetal muscle growth may be improved by strategies that increase oxygen availability.

Low birth weight and its relation to physical fitness parameters in children: Its negative effect on muscle strength and cardiorespiratory endurance

BACKGROUND

There is increasing evidence that low birth weight has a negative effect on physical fitness, muscle strength, and cardiorespiratory endurance, although the findings are inconsistent.

OBJECTIVES

This study aimed to evaluate whether birth weight acts as a prenatal determinant of physical fitness parameters and to determine the role of environmental or biological variables on this effect.

METHODS

One hundred and sixty-seven children aged 6-14 years were included in this study. The anthropometric data, physical activity index, standing long jump, flexibility, handgrip strength, and cardiorespiratory fitness were evaluated.

RESULTS

A positive correlation was found between birth weight and cardiorespiratory fitness (r = .349; p < .001), right handgrip strength (r = .337; p < .001), and left handgrip strength (r = .320; p < .001), suggesting that children with low birth weight had the worst performance in both cardiorespiratory endurance and grip strength tests. These findings remained significant after adjustment for prematurity, sex, age, physical activity index, and body mass index (BMI). Stepwise multiple regression analyses revealed a significant interaction of high birth weight, older age, and low BMI in predicting better cardiorespiratory endurance (R² = .308). When handgrip strength was tested as the dependent variable, we found that high birth weight, male sex, and older age emerged as important determinants for both sides.

CONCLUSION

Children aged 6-14 years born with a birth weight < 2.5 kg have low handgrip strength and cardiorespiratory fitness, which seems to be mediated partially by influences of both prenatal environment (e.g., birth weight) and biological variables (e.g., age, sex, BMI).

Birth weight and body composition in 6-to-8 years old Maya children

OBJECTIVE

To test the hypothesis that fetal growth, indexed by birth weight (BW), induce metabolic adjustments in the fetus that will be reflected in differences in body composition in a sample of 6-to 8-years old urban Maya children from Yucatan, Mexico.

METHODS

We measured height (cm), weight (kg) and triceps skinfold (mm) in 260 children (boys: 132, girls: 128), and height (cm) and weight (kg) in their mothers. Body composition was estimated in children through bioelectrical impedance analysis. Outcome variables were fat free-mass index (FFMI = fat-free mass [kg]/height [m]² ) and fat mass index (FMI = fat mass [kg]/height [m]² ). The main independent variable was BW z-scores. Multiple linear regression models were used to analyze the association between BW z-scores and outcome variables measured during childhood. Separate analyses were done for boys and girls. Complementary models were run using outcomes as z-scores. Models were adjusted for location, children's and mothers' age, mother's body mass index and household overcrowding index.

RESULTS

BW in boys was positively associated with FFMI and FMI. FFMI increase 0.34 kg/m² per 1-SD increase in BW and FMI increase 0.40 kg/m² per 1-SD increase in BW. When outcomes were used as z-scores, FFMI increase 0.24 SD and FMI increase 0.18 SD per 1-SD increase in BW, respectively.

CONCLUSION

Our results are in contrast with previous findings that birth weight is more consistently associated with subsequent lean mass than with fat mass. Associations, detected only in boys, may be explained by sex differences in sensitivity to early life environments.

Prenatal exposure to traffic and ambient air pollution and infant weight and adiposity: The Healthy Start study

BACKGROUND

Prenatal exposures to ambient air pollution and traffic have been associated with adverse birth outcomes, and may also lead to an increased risk of obesity. Obesity risk may be reflected in changes in body composition in infancy.

OBJECTIVE

To estimate associations between prenatal ambient air pollution and traffic exposure, and infant weight and adiposity in a Colorado-based prospective cohort study.

METHODS

Participants were 1125 mother-infant pairs with term births. Birth weight was recorded from medical records and body composition measures (fat mass, fat-free mass, and adiposity [percent fat mass]) were evaluated via air displacement plethysmography at birth (n = 951) and at ~5 months (n = 574). Maternal residential address was used to calculate distance to nearest roadway, traffic density, and ambient concentrations of fine particulate matter (PM_2.5) and ozone (O₃) via inverse-distance weighted interpolation of stationary monitoring data, averaged by trimester and throughout pregnancy. Adjusted linear regression models estimated associations between exposures and infant weight and body composition.

RESULTS

Participants were urban residents and diverse in race/ethnicity and socioeconomic status. Average ambient air pollutant concentrations were generally low; the median, interquartile range (IQR), and range of third trimester concentrations were 7.3 μg/m³ (IQR: 1.3, range: 3.3-12.7) for PM_2.5 and 46.3 ppb (IQR: 18.4, range: 21.7-63.2) for 8-h maximum O_3. Overall there were few associations between traffic and air pollution exposures and infant outcomes. Third trimester O₃ was associated with greater adiposity at follow-up (2.2% per IQR, 95% CI 0.1, 4.3), and with greater rates of change in fat mass (1.8 g/day, 95% CI 0.5, 3.2) and adiposity (2.1%/100 days, 95% CI 0.4, 3.7) from birth to follow-up.

CONCLUSIONS

We found limited evidence of an association between prenatal traffic and ambient air pollution exposure and infant body composition. Suggestive associations between prenatal ozone exposure and early postnatal changes in body composition merit further investigation.

Large-for-gestational-age phenotypes and obesity risk in adulthood: a study of 195,936 women

While there is evidence that being born large-for-gestational-age (LGA) is associated with an increased risk of obesity later in life, the data are conflicting. Thus, we aimed to examine the associations between proportionality at birth and later obesity risk in adulthood. This was a retrospective study using data recorded in the Swedish Birth Register. Anthropometry in adulthood was assessed in 195,936 pregnant women at 10-12 weeks of gestation. All women were born at term (37-41 weeks of gestation). LGA was defined as birth weight and/or length ≥2.0 SDS. Women were separated into four groups: appropriate-for-gestational-age according to both weight and length (AGA - reference group; n = 183,662), LGA by weight only (n = 4,026), LGA by length only (n = 5,465), and LGA by both weight and length (n = 2,783). Women born LGA based on length, weight, or both had BMI 0.12, 1.16, and 1.08 kg/m² greater than women born AGA, respectively. The adjusted relative risk (aRR) of obesity was 1.50 times higher for those born LGA by weight and 1.51 times for LGA by both weight and height. Length at birth was not associated with obesity risk. Similarly, women born LGA by ponderal index had BMI 1.0 kg/m² greater and an aRR of obesity 1.39 times higher than those born AGA. Swedish women born LGA by weight or ponderal index had an increased risk of obesity in adulthood, irrespective of their birth length. Thus, increased risk of adult obesity seems to be identifiable from birth weight and ignoring proportionality.

Different levels of cardiometabolic indicators in multiple vs. singleton children

BACKGROUND

We aimed to compare cardiometabolic indicators in singletons and multiples at age 7 and explore the birthweight mediation effect.

METHODS

We studied 5431 singletons and 103 sets of multiples from Generation XXI birth cohort. Anthropometric measurements, body composition, and fasting blood samples were obtained. Age- and sex-specific z-scores were calculated (additionally height-specific for blood pressure). Adjusted regression coefficients and respective 95% confidence intervals [β (95%CI)] were computed using path analysis.

RESULTS

Multiples had lower weight [- 0.419 (- 0.616;-0.223)], height [- 0.404 (- 0.594;-0.213)], BMI [- 0.470 (- 0.705;-0.234)], fat mass index [- 0.359 (- 0.565;-0.152)], waist circumference [- 0.342 (- 0.537;-0.147)], and waist-to-height ratio [- 0.165 (- 0.326;-0.003)] z-scores. These results were explained by the indirect effect via birthweight, which was also negative and significant for all the aforementioned cardiometabolic indicators, while no direct effect was present. There were also significant indirect effects regarding fat-free mass index, glucose, insulin, and blood pressure, though the total effects were not significant, due to the balance between direct and indirect effects. The only significant direct effect was regarding diastolic blood pressure [- 0.165 (- 0.302;-0.028)].

CONCLUSIONS

At age 7, multiples presented better cardiometabolic indicators explained by lower weight at birth, except for the lower blood pressure which was independent of an effect via birthweight.

Early life risk factors for childhood obesity-Does physical activity modify the associations? The MoBa cohort study

OBJECTIVES

High maternal pre-pregnancy body mass index (BMI), high birth weight, and rapid infant weight gain are associated with increased risk of childhood obesity. We examined whether moderate-to-vigorous physical activity (MVPA) or vigorous physical activity (VPA) in 9- to 12-year-olds modified the associations between these early life risk factors and subsequent body composition and BMI.

METHODS

We used data from a sub-cohort of the Norwegian Mother and Child Cohort Study (MoBa), including 445 children with available data on accelerometer assessed physical activity (PA). All participants had data on BMI, 186 of them provided data on body composition (dual energy X-ray absorptiometry (DXA)). We used multiple regression analyses to examine the modifying effect of PA by including interaction terms.

RESULTS

Maternal pre-pregnancy BMI and infant weight gain were more strongly related to childhood body composition in boys than in girls. Higher VPA attenuated the association between maternal pre-pregnancy BMI and BMI in boys (low VPA: B = 0.32, 95% CI = 0.22, 0.41; high VPA B = 0.22, 95% CI = 0.12, 0.31). Birth weight was unrelated to childhood body composition, and there was no effect modification by PA. PA attenuated the associations between infant weight gain and childhood fat mass (low MVPA: B = 2.32, 95% CI = 0.48, 4.17; high MVPA: B = 1.00, 95% CI = 0.10, 1.90) and percent fat (low MVPA: B = 3.35, 95% CI = 0.56, 6.14; high MVPA: B = 1.41, 95% CI = -0.06, 2.87) in boys, but not girls.

CONCLUSION

Findings from this study suggest that MVPA and VPA may attenuate the increased risk of an unfavorable body composition and BMI due to high maternal pre-pregnancy BMI and rapid infant weight gain in boys, but not in girls.

Proportionality at birth and left ventricular hypertrophy in healthy adolescents

BACKGROUND

Perinatal growth has important implications for cardiac development. Low birth weight is associated with cardiovascular (CV) events and mortality, and animal studies have shown that fetal growth restriction is associated with cardiac remodeling in the perinatal period leading to a permanent loss of cardiomyocyte endowment and compensatory hypertrophy.

AIMS

To determine associations of birthweight (BW) and multiple proportionality indexes (body mass index (BMI); weight/length² and Ponderal index (PI); weight/length³) at birth on one hand, with left ventricular (LV) structure and function during adolescence.

SUBJECTS

379 healthy adolescents aged 14-18 years in Augusta, Georgia.

OUTCOME MEASURES

LV structure and function parameters, including intraventricular septal thickness in diastole (IVSd), LV internal dimension in diastole (LVIDd), LV internal diameter in systole (LVIDs), LV posterior wall thickness in diastole (LVPWd), relative wall thickness (RWT), midwall fractional shortening (MFS), and ejection fraction, were assessed by echocardiography.

RESULTS

When associations of birthweight, birth BMI, and birth PI with LV structure and function parameters were separately evaluated with linear regression adjusting for age, sex, race, Tanner stage, socioeconomic status, and physical activity, significant positive associations of BW with LVIDd (P = 0.004), birth BMI with LV mass index (P = 0.01), and birth PI with IVSd (P = 0.02), LVPWd (P = 0.03), and LV mass index (P = 0.002) were identified. When LV structure and function parameters were compared across PI tertiles, a significant U-shaped trend for LV mass index (P_quadratic = 0.04) was identified.

CONCLUSIONS

Our adolescent data suggest that proportionality at birth may identify associations between perinatal growth and cardiac remodeling independent of birthweight alone.

Adolescent body composition and associations with body size and growth from birth to late adolescence. The Tromsø study: Fit Futures-A Norwegian longitudinal cohort study

BACKGROUND

Fat and fat-free masses and fat distribution are related to cardiometabolic risk.

OBJECTIVES

to explore how birth weight, childhood body mass index (BMI) and BMI gain were related to adolescent body composition and central obesity.

METHODS

In a population-based longitudinal study, body composition was measured by dual-energy X-ray absorptiometry in 907 Norwegian adolescents (48% girls). Associations between birth weight, BMI categories, and BMI gain were evaluated by fitting linear mixed models and conditional growth models with fat mass index (FMI, kg/m² ), fat-free mass index (FFMI, kg/m² ) standard deviation scores (SDS), and central obesity at 15 to 20 years, as well as change in FMI SDS and FFMI SDS between ages 15 to 17 and 18 to 20 as outcomes.

RESULTS

Birth weight was associated with FFMI in adolescence. Greater BMI gain in childhood, conditioned on prior body size, was associated with higher FMI, FFMI, and central overweight/obesity with the strongest associations seen at age 6 to 16.5 years: FMI SDS: β = 0.67, 95% CI (0.63-0.71), FFMI SDS: 0.46 (0.39, 0.52), in girls, FMI SDS: 0.80 (0.75, 0.86), FFMI SDS: 0.49 (0.43, 0.55), in boys.

CONCLUSIONS

Compared with birth and early childhood, high BMI and greater BMI gain at later ages are strong predictors of higher fat mass and central overweight/obesity at 15 to 20 years of age.

Childhood central adiposity at ages 5 and 9 shows consistent relationship with that of the maternal grandmother but not other grandparents

BACKGROUND

The importance of a life course approach to childhood obesity has been emphasized; however, few studies can prospectively investigate relationships in three-generation families.

OBJECTIVE

To prospectively investigate the relationship between grandparental and grandchild waist circumference (WC) at ages 5 and 9 down maternal and paternal lines.

METHODS

At baseline in the Lifeways Cross-Generation Cohort, 1094 children were born to 1082 mothers; 585 were examined at age 5 and 298 at age 9. Of the total 589 children with measured WC, data were also available from 745 grandparents. Child WC was standardized for age and sex, and theory-based hierarchical linear regression was used.

RESULTS

Maternal grandmother (MGM) WC was predictive of grandchild WC at both time points. At age 5, grandchild's standardized birth weight (B = 0.266, p = 0.001), mother's means tested eligibility for free medical care (B = 1.029, p = 0.001) and grandchild seeing maternal grandparents daily (B = 0.312, p = 0.048) were significant alongside MGM WC (B = 0.015, p = 0.019). At age 9, only MGM WC (B = 0.022, p = 0.033) and mother's WC (B = 0.032, p = 0.005) were significant. Mediation analysis with mother's WC showed significant direct relationship of MGM and grandchild WC.

CONCLUSIONS

This prospective cross-generational cohort shows consistent patterns of association between MGM and grandchild WC, not seen in other grandparental lineages.

Breech presentation is associated with lower bone mass and area: findings from the Southampton Women's Survey

We compared bone outcomes in children with breech and cephalic presentation at delivery. Neonatal whole-body bone mineral content (BMC) and area were lower in children with breech presentation. At 4 years, no differences in whole-body or spine measures were found, but hip BMC and area were lower after breech presentation.

INTRODUCTION

Breech presentation is associated with altered joint shape and hip dysplasias, but effects on bone mineral content (BMC), area (BA) and density (BMD) are unknown.

METHODS

In the prospective Southampton Women's Survey mother-offspring cohort, whole-body bone outcomes were measured using dual-energy X-ray absorptiometry (DXA) in 1430 offspring, as neonates (mean age 6 days, n = 965, 39 with a breech presentation at birth) and/or at age 4.1 years (n = 999, 39 breech). Hip and spine bone outcomes were also measured at age 4 years.

RESULTS

Neonates with breech presentation had 4.2 g lower whole-body BMC (95% CI -7.4 to - 0.9 g, P = 0.012) and 5.9 cm² lower BA (- 10.8 to - 1.0 cm², P = 0.019), but BMD was similar between groups (mean difference - 0.007, - 0.016 to 0.002 g/cm², P = 0.146) adjusting for sex, maternal smoking, gestational diabetes, mode of delivery, social class, parity, ethnicity, age at scan, birthweight, gestational age and crown-heel length. There were no associations between breech presentation and whole-body outcomes at age 4 years, but, in similarly adjusted models, regional DXA (not available in infants) showed that breech presentation was associated with lower hip BMC (- 0.51, - 0.98 to - 0.04 g, P = 0.034) and BA (- 0.67, - 1.28 to - 0.07 cm², P = 0.03) but not with BMD (- 0.009, - 0.029 to 0.012 g, P = 0.408), or spine outcomes.

CONCLUSIONS

These results suggest that breech presentation is associated with lower neonatal whole-body BMC and BA, which may relate to altered prenatal loading in babies occupying a breech position; these differences did not persist into later childhood. Modest differences in 4-year hip BMC and BA require further investigation.

High-fat diet reduces weight gain but increases other cardio-metabolic indices in offspring of normotensive and hypertensive rats

This study investigated the effect of post-natal consumption of high-fat diet (HFD) on cardio-metabolic indices in male offspring of hypertensive female rats. There were neither significant differences in body weight gain either in pups from normotensive or hypertensive dams that received normal diet during the post-weaning periods (except at 7th and 9th weeks), nor in both pup groups that received HFD. However, both pup groups that received HFD had reduced body weight gain when compared to their counterparts that received normal diet. Post-weaning administration of HFD to pups of hypertensive and normotensive dams significantly increased their blood glucose, pressure and lipid profiles when compared to those weaned to normal diet. It was concluded that male offspring consumption of HFD diet elicits cardio-metabolic disturbance that slightly depended of maternal cardiovascular status but majorly depended on post-weaning weight gain, while that elicited by maternal hypertension is not related to post-weaning weight gain.

Birth weight, physical growth and body composition in children: A longitudinal study

ABSTRACT Objective To describe children’s physical growth (body mass and height) velocity and body composition (fat percentage and Fat Free Mass); to investigate the magnitude of interindividual differences according to age, gender and birth weight categories, as well as to examine the differences in the average trajectories of children with Low Birth Weight and Normal Weight according to international references. Methods The sample consisted of 534 children (279 boys and 255 girls, 7 to 10 years old) evaluated in the first year of study and followed for 3 years with overlap between the ages of 7 and 9 years. Physical growth and body composition measurements included: height, body mass, fat percentage (%Fat) and Fat Free Mass. Multilevel Modelling was used. Results Birth weight was not associated with physical growth and body composition markers at 7 years old or with the velocity of their changes (p>0.05). There were significant interindividual differences in the trajectories of physical growth (height and body mass; p<0.001) and body composition (%Fat and Fat Free Mass; p<0.001). In plotting on international percentile charts, the trajectories of growth and body composition were within expected values for age and gender, regardless of birth weight. Conclusion There are significant differences in the dynamics of stature growth, body mass and Fat Free Mass, and Low Birth Weight has no influence on this trajectory. In addition, values are within the expected range for age and sex.

A pragmatic controlled trial to prevent childhood obesity within a risk group at maternity and child health-care clinics: results up to six years of age (the VACOPP study)

Background

Obesity in childhood appears often during the toddler years. The prenatal environment influences obesity risk. Maternal gestational diabetes, the child’s diet, and physical activity in the first few years have an important role in subsequent weight gain. A study was conducted to evaluate effectiveness of a primary health-care lifestyle counselling intervention in prevention of childhood obesity up to 6 years of age.

Methods

The study was a controlled pragmatic trial to prevent childhood obesity and was implemented at maternity and child health-care clinics. The participants (n = 185) were mothers at risk of gestational diabetes mellitus with their offspring born between 2008 and 2010. The prenatal intervention, started at the end of the first trimester of pregnancy, consisted of counselling on diet and physical activity by municipal health-care staff. The intervention continued at yearly appointments with a public health-nurse at child health-care clinics. The paper reports the offspring weight gain results for 2–6 years of age. Weight gain up to 6 years of age was assessed as BMI standard deviation scores (SDS) via a mixed-effect linear regression model. The proportion of children at 6 years with overweight/obesity was assessed as weight-for-height percentage and ISO-BMI. Priority was not given to power calculations, because of the study’s pragmatic nature.

Results

One hundred forty seven children’s (control n = 76/85% and intervention n = 71/56%) weight and height scores were available for analysis at 6 years of age. There was no significant difference in weight gain or overweight/obesity proportions between the groups at 6 years of age, but the proportion of children with obesity in both groups was high (assessed as ISO-BMI 9.9% and 11.8%) relative to prevalence in this age group in Finland.

Conclusion

As the authors previously reported, the intervention-group mothers had lower prevalence of gestational diabetes mellitus, but a decrease in obesity incidence before school age among their offspring was not found. The authors believe that an effective intervention should start before conception, continuing during pregnancy and the postpartum period through the developmentally unique child’s first years.

Trial registration

ClinicalTrials.gov NCT00970710. Registered 1 September 2009. Retrospectively registered.

Prenatal Exposure to Perfluoroalkyl Substances and Body Fatness in Girls

BACKGROUND

Perfluoroalkyl substances (PFASs) are used in surface coatings that resist stains, grease, and water.

METHODS

The association between in utero PFAS exposure and girls' body fatness at age 9 was analyzed in The Avon Longitudinal Study of Parents and Children (UK). Maternal serum [median 15 weeks: interquartile range (IQR) 10 and 28 weeks of gestation] was analyzed for perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA). Body composition was measured by dual X-ray emission absorptiometry, and percent total body fat (%BF) was calculated. Associations between PFASs and body fatness were modeled by multivariable linear regression.

RESULTS

Among 359 girls, median (IQR) %BF was 27.5 (IQR 21.7-34.6). Median (IQR) concentrations (all ng/mL) were 3.7 (2.9-4.8) for PFOA, 19.8 (15.0-25.3) for PFOS, 1.6 (1.3-2.2) for PFHxS, and 0.5 (0.4-0.7) for PFNA. Maternal PFAS concentrations were not significantly associated with daughters' total %BF overall. Mothers' educational status modified associations for PFOA and PFOS with %BF (P-interactions: 0.005 and 0.02, respectively). %BF was higher [1.4%; 95% confidence interval (95% CI): 0.3 to 2.5] for each one unit (ng/mL) higher PFOA among girls with mothers in the middle education group, but lower (-0.6%; 95% CI: -1.12 to -0.04) for the corresponding comparison among girls with mothers with the highest education. %BF was lower (-0.2%; 95% CI: -0.3 to -0.1) for each one unit higher PFOS among girls with the most educated mothers.

CONCLUSIONS

Prenatal exposure to PFOA and PFOS was associated with girls' %BF within some strata of maternal education status. PFHxS and PFNA were not associated with %BF.

Does Fetal Growth Restriction Cause Later Obesity? Pitfalls in Analyzing Causal Mediators as Confounders

Recent studies finding that small-for-gestational-age (SGA) birth is associated with increased adiposity in childhood and adulthood have been based on analyses "adjusting" for height, weight, or body mass index (BMI; weight (kg)/height (m)2) measured concurrently with the adiposity measurement. To assess the potential for bias due to overadjustment for a causal mediator, we compared 2 approaches to analyzing the association between SGA birth and adiposity outcomes (skinfold thicknesses and bioelectrical impedance measurement of body fat) at age 11.5 years using the same data set in a cohort of Belarusian children followed from birth in 1996-1997 to age 11.5 years in 2008-2010. We 1) studied the association of SGA birth with adiposity, adjusting for baseline covariates only, and 2) made additional regression adjustment for concurrent height, weight, or BMI. The first approach yielded negative associations between SGA birth and all adiposity outcomes. Additional adjustment for concurrent weight or BMI reversed (i.e., to positive) the SGA-adiposity association. To explore the latter anthropometric measures as causal mediators, we also used marginal structural models to estimate the controlled direct effect of SGA birth. That effect was similar to the effect seen with the first approach when modeled on height, was null when modeled on BMI, but was confounded by differences in lean mass versus fat mass when modeled on weight.

Impact of Early Nutrition on Body Composition in Children Aged 9.5 Years Born with Extremely Low Birth Weight

To evaluate body composition, metabolism and growth as well as their interaction with early nutrition in former extremely low birth weight infants (ELBW), we assessed qualitative and quantitative nutritional intake during initial hospitalization and infantile growth parameters in 61 former ELBW infants with a birth weight <1000 g. In two follow-up exams, physical and biochemical development were measured at 5.7 and at 9.5 years. At the second follow-up, in addition to biochemical reassessment, body composition was analyzed by dual-energy x-ray absorptiometry (DEXA). Protein intake between birth and discharge was associated with weight gain in the first six months of life (r = 0.51; p < 0.01). Weight catch-up preceded height catch-up. Protein intake in early infancy correlated highly significantly with abdominal fat mass (r = 0.49; p < 0.05), but not with lean body mass at 9.5 years (r = 0.30; not significant (n.s.). In contrast to nutrient intake, birth weight was associated with lean body mass (r = 0.433; p < 0.001). Early protein and carbohydrate intake were associated with high-density lipoprotein (HDL)-cholesterol, and early catch-up growth correlated with fasting insulin at follow-up. Stepwise linear regression demonstrated that protein intake predicted fat mass (p < 0.05), whereas only gender and birth weight standard deviation score (SDS) contributed significantly to lean body mass variation (p < 0.05). Our results suggest an important impact of early nutrient intake on body composition and metabolism in later childhood in ELBW children.

Programming of Adiposity in Childhood and Adolescence: Associations With Birth Weight and Cord Blood Adipokines

CONTEXT

Exposure to maternal adiposity during pregnancy is associated with higher offspring birth weight and greater adiposity through childhood and adult life. As birth weight reflects the summation of lean and fat mass, the extent to which fat mass at birth tracks into later life is unknown.

OBJECTIVE

To determine whether fat mass at birth is associated with child and adolescent adiposity.

DESIGN, SETTING, AND PARTICIPANTS

UK birth cohort with markers of neonatal fat mass; cord blood leptin, adiponectin, and birth weight and adiposity outcomes at age 9 (n = 2775) and 17 years (n = 2138).

MAIN OUTCOMES

Offspring body mass index (BMI), waist circumference, dual-energy X-ray absorptiometry-determined fat mass, and obesity at age 9 and 17 years.

RESULTS

Higher cord blood leptin was associated with higher z scores of fat mass [difference in mean per 10 pg/mL: 0.03 standard deviation (SD); 95% confidence interval (CI), 0.00 to 0.06], waist circumference (0.04 SD; 95% CI, 0.00 to 0.07), and BMI (0.04 SD; 95% CI, 0.00 to 0.08) at age 9. However, by age 17 the adjusted results were attenuated to the null. Cord blood adiponectin was not associated with measures of adiposity at age 9. At age 17, cord blood adiponectin was positively associated with fat mass (0.02 SD per 10 μg/mL; 95% CI, 0.02 to 0.03) and waist circumference (0.04 SD per 10 μg/mL; 95% CI, 0.03 to 0.05). Birth weight was positively associated with waist circumference (0.03 SD per 100 g; 95% CI, 0.02 to 0.04) and BMI (0.02 SD per 100 g; 95% CI, 0.00 to 0.03), but not fat mass or odds of obesity. Cord blood leptin and adiponectin were not associated with obesity at either age.

CONCLUSIONS

Increased cord blood leptin and adiponectin, known surrogates of fetal fat mass, were weakly associated with increased fat mass in late childhood and adolescence, respectively.

Prenatal, birth and early life predictors of sedentary behavior in young people: a systematic review

BACKGROUND

Our aim was to systematically summarize the evidence on whether prenatal, birth and early life factors up to 6 years of age predict sedentary behavior in young people (≤18 years).

METHODS

PRISMA guidelines were followed, and searches were conducted in PubMed, SPORTDiscus, EMBASE and Web of Science up to December 1, 2015. We included observational (non-intervention) and longitudinal studies, that reported data on the association between one or more of the potential predictors and objectively or subjectively measured sedentary behavior. Study quality was assessed using a formal checklist and data extraction was performed using standardized forms independently by two researchers.

RESULTS

More than 18,000 articles were screened, and 16 studies, examining 10 different predictors, were included. Study quality was variable (0.36-0.95). Two studies suggest that heritability and BMI in children aged 2-6 years were significant predictors of sedentary behavior later in life, while four and seven studies suggest no evidence for an association between gestational age, birth weight and sedentary behavior respectively. There was insufficient evidence whether other prenatal, birth and early life factors act as predictors of later sedentary behavior in young people.

CONCLUSION

The results suggest that heritability and early childhood BMI may predict sedentary behavior in young people. However, small number of studies included and methodological limitations, including subjective and poorly validated sedentary behavior assessment, limits the conclusions.

TRIAL REGISTRATION

The systematic review is registered in the International Prospective Register of Systematic Reviews, PROSPERO, 17.10.2014 ( CRD42014014156 ).

Diet, growth, and obesity development throughout childhood in the Avon Longitudinal Study of Parents and Children

Publications from the Avon Longitudinal Study of Parents and Children covering diet, growth, and obesity development during childhood are reviewed. Diet was assessed by food frequency questionnaires and food records. Growth data were collected by routine measurements, and in standardized clinics, body fatness was assessed by bioelectrical impedance and DXA (dual-energy X-ray absorptiometry) scans. Diets changed dramatically during the preschool period with an increase in the intake of free (added) sugars (12.3% rising to 16.4% of energy) that remained similar until adolescence. This was due to increased intake of energy-dense, nutrient-poor foods. Two periods of rapid growth were identified; infancy and mid-childhood (ages 7-11 y) and both were associated with obesity development. Diets with high energy density were associated with increasing fat mass from mid-childhood until adolescence. Genetic and dietary factors showed independent associations with increasing adiposity. At all ages studied, there were dietary inequalities related to maternal educational attainment that may influence inequalities found in obesity development. The Avon Longitudinal Study of Parents and Children has provided valuable insights into how disparities in diet and growth may affect the development of ill health in adulthood.

The role of grandparents in childhood obesity in China - evidence from a mixed methods study

BACKGROUND

The current literature on the influences of family environment on childhood obesity is predominantly based on western populations and has focused on the role of parents. This study examined the influence of grandparents on the development of obesity among Chinese primary school aged children.

METHODS

A mixed methods study was conducted in four socioeconomically distinct primary school communities in two cities of southern China. The qualitative study (17 focus groups and four personal interviews) involved parents, grandparents, school staff, and food retailers in the vicinity of the schools (n = 99) and explored perceived causes of childhood obesity. The cross-sectional study examined the association between children's objectively measured weight status and reported health behaviours, and the presence and role of grandparents in the household. It included children from three randomly selected third grade (8 to 10 years) classes from each school (n = 497).

RESULTS

Grandparents were commonly perceived to contribute to childhood obesity through inappropriate perception (e.g. fat children are healthy and well cared for), knowledge (e.g. obesity related diseases can only happen in adults; the higher the dietary energy/fat content, the more nutritious the food), and behaviour (e.g. overfeeding and indulging through excusing the children from household chores). Conflicting child care beliefs and practices between grandparents and parents, and between grandparents and school teachers, were felt to undermine efforts to promote healthy behaviours in children. In the cross-sectional study, children who were mainly cared for by their grandparents were more likely to be overweight/obese (adjusted OR = 2.03; 95 % CI = 1.19 to 3.47); and to consume more sugar-added drinks and unhealthy snacks (B = 2.13, 95 % CI = 0.87 to 3.40), than children who were mainly cared for by their parents or other adult. Children who lived with two or more grandparents in the household were more likely to be overweight/obese than children who did not live with any grandparent (adjusted OR = 1.72; 95 % CI = 1.00 to 2.94).

CONCLUSIONS

Involvement of grandparents in childcare is an important factor contributing to childhood obesity in China. Future preventive interventions should include strategies that target grandparents.

Association between birth weight and objectively measured sedentary time is mediated by central adiposity: data in 10,793 youth from the International Children's Accelerometry Database

BACKGROUND

Birth weight is an early correlate of disease later in life, and animal studies suggest that low birth weight is associated with reduced activity and increased sedentary time. Whether birth weight predicts later sedentary time in humans is uncertain.

OBJECTIVES

We examined the relation between birth weight and sedentary time in youth and examined whether this association was mediated by central adiposity.

DESIGN

We used pooled cross-sectional data from 8 observational studies conducted between 1997 and 2007 that consisted of 10,793 youth (boys: 47%) aged 6-18 y from the International Children's Accelerometry Database. Birth weight was measured in hospitals or maternally reported, sedentary time was assessed by using accelerometry (<100 counts/min), and abdominal adiposity (waist circumference) was measured according to WHO procedures. A mediation analysis with bootstrapping was used to analyze data.

RESULTS

The mean (±SD) time spent sedentary was 370 ± 91 min/d. Birth weight was positively associated with sedentary time (B = 4.04, P = 0.006) and waist circumference (B = 1.59, P < 0.001), whereas waist circumference was positively associated with sedentary time (B = 0.82, P < 0.001). Results of the mediation analysis showed a significant indirect effect of birth weight on sedentary time through waist circumference (B: 1.30; 95% bias-corrected CI: 0.94, 1.72), and when waist circumference was controlled for, the effect of birth weight on sedentary time was attenuated by 32% (B = 2.74, P = 0.06).

CONCLUSION

The association between birth weight and sedentary time appears partially mediated by central adiposity, suggesting that both birth weight and abdominal adiposity may be correlates of sedentary time in youth.

Overweight and obesity in children and adolescents

Obesity among children, adolescents and adults has emerged as one of the most serious public health concerns in the 21st century. The worldwide prevalence of childhood obesity has increased remarkably over the past 3 decades. The growing prevalence of childhood obesity has also led to appearance of obesity-related comorbid disease entities at an early age. Childhood obesity can adversely affect nearly every organ system and often causes serious consequences, including hypertension, dyslipidemia, insulin resistance, dysglycemia, fatty liver disease and psychosocial complications. It is also a major contributor to increasing healthcare expenditures. For all these reasons, it is important to prevent childhood obesity as well as to identify overweight and obese children at an early stage so they can begin treatment and attain and maintain a healthy weight. At present, pharmacotherapy options for treatment of pediatric obesity are very limited. Therefore, establishing a comprehensive management program that emphasizes appropriate nutrition, exercise and behavioral modification is crucial. The physician's role should expand beyond the clinical setting to the community to serve as a role model and to advocate for prevention and early treatment of obesity.

The relationship of birthweight, muscle size at birth and post-natal growth to grip strength in 9-year-old Indian children: findings from the Mysore Parthenon study

Foetal development may permanently affect muscle function. Indian newborns have a low mean birthweight, predominantly due to low lean tissue and muscle mass. We aimed to examine the relationship of birthweight, and arm muscle area (AMA) at birth and post-natal growth to handgrip strength in Indian children. Grip strength was measured in 574 children aged 9 years, who had detailed anthropometry at birth and every 6-12 months post-natally. Mean (standard deviation (s.d.)) birthweight was 2863 (446) g. At 9 years, the children were short (mean height s.d. -0.6) and light (mean weight s.d. -1.1) compared with the World Health Organization growth reference. Mean (s.d.) grip strength was 12.7 (2.2) kg (boys) and 11.0 (2.0) kg (girls). Weight, length and AMA at birth, but not skinfold measurements at birth, were positively related to 9-year grip strength (β = 0.40 kg/s.d. increase in birthweight, P < 0.001; and β = 0.41 kg/s.d. increase in AMA, P < 0.001). Grip strength was positively related to 9-year height, body mass index and AMA and to gains in these measurements from birth to 2 years, 2-5 years and 5-9 years (P < 0.001 for all). The associations between birth size and grip strength were attenuated but remained statistically significant for AMA after adjusting for 9-year size. We conclude that larger overall size and muscle mass at birth are associated with greater muscle strength in childhood, and that this is mediated mainly through greater post-natal size. Poorer muscle development in utero is associated with reduced childhood muscle strength.

Is restricted fetal growth associated with later adiposity? Observational analysis of a randomized trial

BACKGROUND

Several recent "developmental origins" studies have reported increased long-term risks of adiposity, especially truncal adiposity, among children born small for gestational age (SGA).

OBJECTIVE

We assessed the effects of SGA birth and weight gain in early infancy on adiposity at age 11.5 y.

DESIGN

From a cluster-randomized breastfeeding promotion trial in 17,046 Belarusian children, we measured height, weight, waist and hip circumferences, triceps and subscapular skinfold thicknesses, and bioimpedance measures of percentage body fat at age 11.5 y. Children born SGA (birth weight <10th percentile) and those born large for gestational age (LGA; >90th percentile for gestational age) were compared with those born appropriate for gestational age (AGA). Weight gain from birth to 6 mo was categorized as high (>0.67-SD increase in weight-for-age), low (>0.67-SD decrease in weight-for-age), or normal. Multilevel statistical models accounted for clustered measurement and controlled for maternal and paternal height and body mass index (BMI), maternal education, geographic region, urban compared with rural residence, and the child's exact age at follow-up.

RESULTS

Children born SGA had a significantly lower BMI, percentage body fat, and fat mass index than did those born AGA, with a dose-response effect across 2 subcategories of SGA (P < 0.001 for all comparisons). No difference was observed in waist-to-hip ratio, although the subscapular-to-triceps skinfold ratio was slightly but significantly (P < 0.001) higher in children born SGA. Differences among the study groups continued to increase since the previous follow-up at 6.5 y. SGA infants with catch-up growth in the first 3-6 mo had growth and adiposity measures intermediate between those born SGA without catch-up and those born AGA. Opposite effects of similar magnitude were observed in children born LGA.

CONCLUSION

The 11.5-y-old Belarusian children born SGA were shorter, were thinner, and had less body fat than their non-SGA peers, irrespective of postnatal weight gain. The Promotion of Breastfeeding Intervention Trial was registered at www.isrctn.org as ISRCTN-37687716.

Effects of BMI, fat mass, and lean mass on asthma in childhood: a Mendelian randomization study

BACKGROUND

Observational studies have reported associations between body mass index (BMI) and asthma, but confounding and reverse causality remain plausible explanations. We aim to investigate evidence for a causal effect of BMI on asthma using a Mendelian randomization approach.

METHODS AND FINDINGS

We used Mendelian randomization to investigate causal effects of BMI, fat mass, and lean mass on current asthma at age 7½ y in the Avon Longitudinal Study of Parents and Children (ALSPAC). A weighted allele score based on 32 independent BMI-related single nucleotide polymorphisms (SNPs) was derived from external data, and associations with BMI, fat mass, lean mass, and asthma were estimated. We derived instrumental variable (IV) estimates of causal risk ratios (RRs). 4,835 children had available data on BMI-associated SNPs, asthma, and BMI. The weighted allele score was strongly associated with BMI, fat mass, and lean mass (all p-values<0.001) and with childhood asthma (RR 2.56, 95% CI 1.38-4.76 per unit score, p = 0.003). The estimated causal RR for the effect of BMI on asthma was 1.55 (95% CI 1.16-2.07) per kg/m2, p = 0.003. This effect appeared stronger for non-atopic (1.90, 95% CI 1.19-3.03) than for atopic asthma (1.37, 95% CI 0.89-2.11) though there was little evidence of heterogeneity (p = 0.31). The estimated causal RRs for the effects of fat mass and lean mass on asthma were 1.41 (95% CI 1.11-1.79) per 0.5 kg and 2.25 (95% CI 1.23-4.11) per kg, respectively. The possibility of genetic pleiotropy could not be discounted completely; however, additional IV analyses using FTO variant rs1558902 and the other BMI-related SNPs separately provided similar causal effects with wider confidence intervals. Loss of follow-up was unlikely to bias the estimated effects.

CONCLUSIONS

Higher BMI increases the risk of asthma in mid-childhood. Higher BMI may have contributed to the increase in asthma risk toward the end of the 20th century. Please see later in the article for the Editors' Summary.

Fetal and infant growth patterns associated with total and abdominal fat distribution in school-age children

CONTEXT

Higher infant growth rates are associated with an increased risk of obesity in later life.

OBJECTIVE

We examined the associations of longitudinally measured fetal and infant growth patterns with total and abdominal fat distribution in childhood.

DESIGN, SETTING, AND PARTICIPANTS

We performed a population-based prospective cohort study among 6464 children. We measured growth characteristics in the second and third trimesters of pregnancy, at birth, and at 6, 12, and 24 months.

MAIN OUTCOME MEASURES

Body mass index, fat mass index (body fat mass/height(2)), lean mass index (body lean mass/height(2)), android/gynoid fat ratio measured by dual-energy x-ray absorptiometry, and sc and preperitoneal abdominal fat measured by ultrasound at the median age of 6.0 years (90% range, 5.7-7.4).

RESULTS

We observed that weight gain in the second and third trimesters of fetal life and in early, mid, and late infancy were independently and positively associated with childhood body mass index (P < .05). Only infant weight gain was associated with higher fat mass index, android/gynoid fat ratio, and abdominal fat in childhood (P < .05). Children with both fetal and infant growth acceleration had the highest childhood body mass index, fat mass index, and sc abdominal fat, whereas children with fetal growth deceleration and infant growth acceleration had the highest value for android/gynoid fat ratio and the lowest value for lean mass index (P < .05).

CONCLUSIONS

Growth in both fetal life and infancy affects childhood body mass index, whereas only infant growth directly affects measured total body and abdominal fat. Fetal growth deceleration followed by infant growth acceleration may lead to an adverse body fat distribution in childhood.

Environment-physiology, diet quality and energy balance: the influence of early life nutrition on future energy balance

Diseases caused by impaired regulation of energy balance, in particular obesity, represent a major global health burden. Although polymorphisms, lifestyle and dietary choices have been associated with differential risk of obesity and related conditions, a substantial proportion of the variation in disease risk remains unexplained. Evidence from epidemiological studies, natural experiments and from studies in animal models has shown that a poor intra-uterine environment is associated causally with increased risk of obesity and metabolic disease in adulthood. Induction of phenotypes that increase disease risk involves the fetus receiving cues from the mother about the environment which, via developmental plasticity, modify the phenotype of the offspring to match her environment. However, inaccurate information may induce an offspring phenotype that is mismatched to the future environment. Such mismatch has been suggested to underlie increased risk of metabolic disease associated with a poor early life environment. Recent studies have shown that induction of modified phenotypes in the offspring involves altered epigenetic regulation of specific genes. Identification of a central role of epigenetics in the aetiology of obesity and metabolic disease may facilitate the development of novel therapeutic interventions and of biomarkers of disease risk.

Maternal antenatal vitamin D status and offspring muscle development: findings from the Southampton Women's Survey

CONTEXT

Maternal 25-hydroxyvitamin D [25(OH)D] status in pregnancy has been associated with offspring bone development and adiposity. Vitamin D has also been implicated in postnatal muscle function, but little is known about a role for antenatal 25(OH)D exposure in programming muscle development.

OBJECTIVE

We investigated the associations between maternal plasma 25(OH)D status at 34 weeks of gestation and offspring lean mass and muscle strength at 4 years of age.

DESIGN AND SETTING

We studied a prospective UK population-based mother-offspring cohort: the Southampton Women's Survey (SWS).

PARTICIPANTS

Initially, 12,583 nonpregnant women were recruited into the SWS, of whom 3159 had singleton pregnancies; 678 mother-child pairs were included in this analysis.

MAIN OUTCOMES MEASURED

At 4 years of age, offspring assessments included hand grip strength and whole-body dual-energy x-ray absorptiometry, yielding lean mass and percent lean mass. Physical activity was assessed by 7-day accelerometry in a subset of children (n=326).

RESULTS

The maternal serum 25(OH)D concentration in pregnancy was positively associated with offspring height-adjusted hand grip strength (β=0.10 SD/SD, P=.013), which persisted after adjustment for maternal confounding factors, duration of breastfeeding, and child's physical activity at 4 years (β=0.13 SD/SD, P=.014). Maternal 25(OH)D was also positively associated with offspring percent lean mass (β=0.11 SD/SD, P=.006), but not total lean mass (β=0.06 SD/SD, P=.15). However, this association did not persist after adjustment for confounding factors (β=0.09 SD/SD, P=.11).

CONCLUSIONS

This observational study suggests that intrauterine exposure to 25(OH)D during late pregnancy might influence offspring muscle development through an effect primarily on muscle strength rather than on muscle mass.

Relationship between Birth Weight and Metabolic Status in Obese Adolescents

Objective. To examine the relationships between birth weight and body mass index, percent body fat, blood lipids, glycemia, insulin resistance, adipokines, blood pressure, and endothelial function in a cohort of obese adolescents. Design and Methods. Ninety-five subjects aged 10-16 years (mean age 13.5 years) with a body mass index >95th centile (mean [±SEM] 33.0 ± 0.6) were utilized from two prospective studies for obesity prevention prior to any interventions. The mean term birth weight was 3527 ± 64 g (range 1899-4990 g;). Results. Body mass index z-score correlated positively with birth weight (r (2) = 0.05, P = 0.03), but not percent body fat. Insulin resistance negatively correlated with birth weight (r (2) = 0.05, P < 0.001), as did fasting plasma insulin (r (2) = 0.05, P < 0.001); both being significantly greater for subjects of small versus large birth weight (Δ Homeostasis Model Assessment = 2.5 and Δ insulin = 10 pmol/L for birth weight <2.5 kg versus >4.5 kg). Adiponectin, but not leptin, blood pressure z-scores or peripheral arterial tomography values positively correlated with birth weight (r (2) = 0.07, P = 0.008). Conclusions. Excess body mass index in obese adolescents was positively related to birth weight. Birth weight was not associated with cardiovascular risk factors but represented a significant determinant of insulin resistance.

Pragmatic controlled trial to prevent childhood obesity in maternity and child health care clinics: pregnancy and infant weight outcomes (the VACOPP Study)

BACKGROUND

According to current evidence, the prevention of obesity should start early in life. Even the prenatal environment may expose a child to unhealthy weight gain; maternal gestational diabetes is known to be among the prenatal risk factors conducive to obesity. Here we report the effects of antenatal dietary and physical activity counselling on pregnancy and infant weight gain outcomes.

METHODS

The study was a non-randomised controlled pragmatic trial aiming to prevent childhood obesity, the setting being municipal maternity health care clinics. The participants (n = 185) were mothers at risk of developing gestational diabetes mellitus and their offspring. The children of the intervention group mothers were born between 2009 and 2010, and children of the control group in 2008. The intervention started between 10-17 gestational weeks and consisted of individual counselling on diet and physical activity by a public health nurse, and two group counselling sessions by a dietician and a physiotherapist. The expectant mothers also received a written information leaflet to motivate them to breastfeed their offspring for at least 6 months. We report the proportion of mothers with pathological glucose tolerance at 26-28 weeks' gestation, the mother's gestational weight gain (GWG) and newborn anthropometry. Infant weight gain from 0 to 12 months of age was assessed as weight-for-length standard deviation scores (SDS) and mixed effect linear regression models.

RESULTS

Intervention group mothers had fewer pathological oral glucose tolerance test results (14.6% vs. 29.2%; 95% CI 8.9 to 23.0% vs. 20.8 to 39.4%; p-value 0.016) suggesting that the intervention improved gestational glucose tolerance. Mother's GWG, newborn anthropometry or infant weight gain did not differ significantly between the groups.

CONCLUSION

Since the intervention reduced the prevalence of gestational diabetes mellitus, it may have the potential to diminish obesity risk in offspring. However, results from earlier studies suggest that the possible effect on the offspring's weight gain may manifest only later in childhood.

TRIAL REGISTRATION

Clinical Trials gov: NCT00970710.

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.

Maternal adiposity--a determinant of perinatal and offspring outcomes?

Experimental and animal data suggest that maternal obesity during pregnancy adversely affects offspring health in the short-term and the long-term. Whether these effects occur in humans and influence population health is less clear. This Review explores evidence from intervention studies and observational studies that have used designs (such as family-based comparisons and Mendelian randomization) that might help improve understanding of the causal effects of maternal obesity in humans. Collectively, human studies provide evidence that maternal overweight and obesity is causally related to pregnancy complications, increased offspring weight and adiposity at birth, and the difficulties associated with delivery of large-for-gestational-age infants. The underlying mechanisms for these effects probably involve maternal and fetal dysregulation of glucose, insulin, lipid and amino acid metabolism. Some evidence exists that extreme maternal obesity (BMI ≥40 kg/m(2)) is causally related to a long-term increase in offspring adiposity, but further exploration of this relationship is needed. High gestational weight gain may result in a long-term increase in offspring adiposity if women are already overweight or have obesity at the start of pregnancy. To date, little high-quality human evidence exists that any of these effects are mediated by epigenetic mechanisms, but approaches to appropriately test this possibility are being developed.

Childhood obesity

Childhood obesity has important consequences for health and wellbeing both during childhood and also in later adult life. The rising prevalence of childhood obesity poses a major public health challenge in both developed and developing countries by increasing the burden of chronic non-communicable diseases. Despite the urgent need for effective preventative strategies, there remains disagreement over its definition due to a lack of evidence on the optimal cut-offs linking childhood BMI to disease risks, and limited evidence on the most effective components of interventions to prevent childhood obesity. This article reviews the trends in childhood obesity, its genetic, nutritional and other risk factors, and preventative and treatment strategies. Particular emphasis is given to early-onset obesity in pre-school children, which, as a precursor to later childhood and adult obesity, provides insights into the developmental and genetic origins of obesity and also offers the potential for early preventative approaches with long-lasting benefits.

Maternal obesity, gestational weight gain and diet as determinants of offspring long term health

This review addresses the increasingly prolific literature from studies in man and animals suggesting that maternal obesity, a diet rich in calories or excess gestational weight gain may, through perturbation of the intrauterine environment, lead to lifelong risk of obesity and related disorders in the child. In addressing maternal- child obesity relationships it remains a challenge to distinguish the influence of the intrauterine environment from the contribution of shared genetic traits, and to adequately adjust for postnatal determinants of childhood obesity. Studies in genetically identical rodents convincingly show that maternal obesity, as well as elements of a hypercalorific diet can permanently influence offspring risk of obesity, and are these are supported by studies in larger mammals. Importantly, dissection of the mechanism in animals has led to description of novel interactive pathways between maternal environment and fetus which are amenable to investigation in humans.

Adiposity in children and adolescents: correlates and clinical consequences of fat stored in specific body depots

The 2011 Pennington Biomedical Research Center's Scientific Symposium focused on adiposity in children and adolescents. The symposium was attended by 15 speakers and other invited experts. The specific objectives of the symposium were to (i) integrate the latest published and unpublished findings on the laboratory and clinical assessment of depot-specific adiposity in children and adolescents, (ii) understand the variation in depot-specific adiposity and related health outcomes associated with age, sex, maturation, ethnicity and other factors and (iii) identify opportunities for incorporating new markers of abdominal obesity into clinical practice guidelines for obesity in children and adolescents. This symposium provided an overview of important new advances in the field and identified directions for future research. The long-term goal of the symposium is to aid in the early identification of children and adolescents who are at increased health risk because of obesity and obesity-related conditions.

Relationship between body mass index at age 3 years and body composition at age 11 years among Japanese children: the Shizuoka population-based study

Background

A few studies reported an association between body weight during early childhood and body composition in later life, as measured by dual-energy X-ray absorptiometry (DXA); however, none of those studies investigated an East Asian population. In a Japanese population, we examined the association between body weight at age 3 years and body composition at age 11 years, as measured using DXA.

Methods

The source population was 726 fifth-grade school children enrolled at 3 public schools in Shizuoka Prefecture, Japan from 2008–2010. All children who lived in the study area went to 1 of these 3 schools. DXA was used to obtain data on body composition, and the Maternal and Child Health Handbook was used to calculate body mass index (BMI). The general linear model was used for statistical analysis.

Results

We were able to analyze data on body composition at age 11 years and BMI in early childhood for 550 children. BMI at age 3 and change in BMI z-score from birth to age 3 were positively associated with bone mineral content (BMC), fat-free soft tissue mass (FFSTM), and fat mass (FM) at age 11. After adjusting for confounding factors, mean BMC, FFSTM, and FM were significantly lower among children who were underweight at age 3 and significantly higher among children who were overweight at age 3, as compared with values for normal-weight children at age 3.

Conclusions

Among Japanese children, body weight at age 3 years predicts body composition at age 11 years.