Infant feeding practices and body mass index up to 7.5 years in the French nationwide ELFE study

BACKGROUND/OBJECTIVES

The infant diet represents one of the main modifiable determinants of early growth. This study aimed to investigate the associations of infant feeding practices with body mass index (BMI) until 7.5 years.

SUBJECTS/METHODS

Analyses were based on data from the French nationwide ELFE birth cohort. Data on breastfeeding (BF) and complementary feeding (CF) were collected monthly from 2 to 10 months. Infant feeding practices were characterized using principal component analyses (PCA) and hierarchical ascendant classification. BMI z-score was computed at 1, 2, 3, 5 and 7.5 years, from data collected in the child's health booklet; 7.5-year overweight was defined according to IOTF references. Associations between infant feeding practices and BMI were investigated by linear regression models adjusted for main confounders.

RESULTS

Ever breastfeeding was not associated with BMI up to 7.5 years. Compared to intermediate breastfeeding duration (1 to <3 months), longer breastfeeding duration (≥6 months) was related to lower 1-year BMI, but not at older ages. Compared to the recommended age at CF introduction (4-6 months), early CF (<4 months) was related to higher BMI up to 5 years with a similar trend at 7.5 years, but not to the risk of overweight. The PCA patterns characterized by early baby cereal introduction and late food pieces introduction or by frequent intake of main food groups were related to a lower BMI up to 7.5 years.

CONCLUSION

Breastfeeding was related with a lower BMI in infancy but not thereafter, whereas an early CF initiation (<4 months) was associated with a higher BMI in childhood.

Prenatal dietary exposure to mixtures of chemicals is associated with allergy or respiratory diseases in children in the ELFE nationwide cohort

INTRODUCTION

Prenatal exposure to environmental chemicals may be associated with allergies later in life. We aimed to examine the association between prenatal dietary exposure to mixtures of chemicals and allergic or respiratory diseases up to age 5.5 y.

METHODS

We included 11,638 mother-child pairs from the French "Étude Longitudinale Française depuis l'Enfance" (ELFE) cohort. Maternal dietary exposure during pregnancy to eight mixtures of chemicals was previously assessed. Allergic and respiratory diseases (eczema, food allergy, wheezing and asthma) were reported by parents between birth and age 5.5 years. Associations were evaluated with adjusted logistic regressions. Results are expressed as odds ratio (OR[95%CI]) for a variation of one SD increase in mixture pattern.

RESULTS

Maternal dietary exposure to a mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons (PAHs) was positively associated with the risk of eczema (1.10 [1.05; 1.15]), this association was consistent across sensitivity analyses. Dietary exposure to one mixture of pesticides was positively associated with the risk of food allergy (1.10 [1.02; 1.18]), whereas the exposure to another mixture of pesticides was positively but slightly related to the risk of wheezing (1.05 [1.01; 1.08]). This last association was not found in all sensitivity analyses. Dietary exposure to a mixture composed by perfluoroalkyl acids, PAHs and trace elements was negatively associated with the risk of asthma (0.89 [0.80; 0.99]), this association was consistent across sensitivity analyses, except the complete-case analysis.

CONCLUSION

Whereas few individual chemicals were related to the risk of allergic and respiratory diseases, some consistent associations were found between prenatal dietary exposure to some mixtures of chemicals and the risk of allergic or respiratory diseases. The positive association between trace elements, furans and PAHs and the risk of eczema, and that between pesticides mixtures and food allergy need to be confirmed in other studies. Conversely, the negative association between perfluoroalkyl acids, PAHs and trace elements and the risk of asthma need to be further explored.

SARS-CoV-2 seroprevalence in French 9-year-old children and their parents after the first lockdown in 2020

Introduction

Children have been significantly less affected by COVID-19 than adults and presented with milder and less symptomatic forms of the disease. However, there has been suggestion that children older than 10 years and adolescents exhibits features closer to that of young adults. Most studies combine children in different age-groups and lack sufficient numbers to explore in detail age specificities. We report data on a population-based sample of 2,555 children at the pivotal age of 9 years.

Methods

In April 2020, the participants in two French nationwide cohorts of children, Elfe and Epipage2, were invited to take part into an online survey about Covid related symptoms and family life during the lockdown. A second questionnaire was sent on May 5. This questionnaire also proposed to the child included in the cohort and to one of his/her parents to take part into a capillary blood collection for Covid serology. Families who agreed to the serological survey were sent kits for dried blood spots self-sampling (DBS) with instructions. Samples were processed with a commercial Elisa test (Euroimmun®, Lübeck, Germany) to detect anti-SARS-CoV-2 antibodies (IgG) directed against the S1 domain of the spike protein of the virus.

Results

Children's acceptance rate for the serological survey was around 60%. 2,555 serological results were analyzed. The weighted prevalence of a positive Elisa Spike serology was 2.8% in 9 yr-old children (95% CI: 1.7%-4.0%). Positive serology was found in 8.6% (7.4%-9.7%) of parents who provided blood. There was a significant association (p < 0.001) between serology of the child and parent from the same household with an odds ratio of 13.8 (7.9-24.2).

Discussion

We have shown that 9-yr old children had a lower susceptibility to SARS-Cov2 infection than adults with the initial Chinese strain, similar to younger children and estimated that around 3% of them have developed antibodies against SARS-Cov2 in France after the first wave of the Covid-19 epidemics.

Prenatal dietary exposure to chemicals and allergy or respiratory diseases in children in the EDEN mother-child cohort

INTRODUCTION

Maternal exposure to food chemicals may increase the risk of allergy and respiratory disorders in offspring. We aimed to assess the association of prenatal dietary exposure to single chemicals and chemical mixtures with allergy or respiratory events reported before age 8 y in children.

METHODS

We included 1428 mother-child pairs enrolled in the EDEN mother-child cohort. Maternal dietary exposure to 209 chemicals and eight associated mixtures was investigated. Allergic and respiratory diseases (wheezing, asthma, allergic rhinitis, eczema and food allergy) were reported by parents between birth and age 8 y. Associations with the studied outcomes were evaluated with three approaches based on adjusted logistic regression, estimating odds ratios (ORs) and 95 % confidence intervals (CIs). First, food chemicals were considered individually, with correction for multiple testing. Second, chemicals selected by elastic net regression were considered simultaneously in a multiple exposure model. Third, predefined mixtures were introduced in the same adjusted logistic regression. Results are expressed as odds ratio (OR[95 % CI]).

RESULTS

Prenatal single exposure to 74 food chemicals was associated with higher risk of allergic rhinitis. Prenatal single exposure to 11 chemicals was associated with higher risk of wheezing. In the multi-exposure approach, risk of wheezing was associated with the pesticides diazinon and triadimenol, and polycyclic aromatic hydrocarbon 5-methylchrysene. Phytoestrogen resveratrol was negatively associated with lower risk of both wheezing and allergic rhinitis, and mycotoxin monoacetoxyscirpenol was negatively associated with risk of eczema. Finally, a chemical mixture composed mainly of trace elements, furans and polycyclic aromatic hydrocarbons, was associated with higher risk of allergic rhinitis (1.33 [1.02;1.73]).

CONCLUSION

Prenatal dietary exposure to chemicals was associated with risk of allergic rhinitis or wheezing up to age 8 y. A few chemicals were associated with other allergic and respiratory diseases. Larger prospective studies are needed to confirm these findings.

Maternal diet during pregnancy and child neurodevelopment up to age 3.5 years: the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort

BACKGROUND

Dietary guidelines available to pregnant women are made to improve maternal health and fetal development. But their adequacy to sustain offspring neurodevelopment has remained understudied.

OBJECTIVES

We assessed the association between compliance with nutritional guidelines during pregnancy and neurodevelopment in preschool children.

METHODS

The analyses were based on data for 6780 to 11,278 children from the Étude Longitudinale Française depuis l'Enfance (ELFE) study, a nationwide birth cohort. Maternal diet during the last 3 mo of pregnancy was evaluated at delivery by using a validated 125-item FFQ. From this FFQ, food group consumption, a diet quality score (adapted National Health and Nutrition Program Guideline Score), and a nutrient intake score (Probability of Adequate Nutrient intake based Diet quality index) were calculated and dietary patterns were derived by principal component analysis. Child neurodevelopment was reported by parents at 1 and 3.5 y with the Child Development Inventory (CDI-1, CDI-3.5) and at 2 y with the MacArthur-Bates Communicative Development Inventories (MB-2), and assessed by a trained investigator at 3.5 y with the Picture Similarities test (British Ability Scales, PS-3.5). Associations between maternal diet and child neurodevelopment were assessed by multivariable linear regression models on standardized variables.

RESULTS

Higher nutrient intake score was associated with higher neurodevelopmental scores from 1 to 3.5 y (β = 0.04; 95% CI: 0.02, 0.06 for CDI-1; β = 0.03; 95% CI: 0.01, 0.05 for MB-2; and β = 0.03; 95% CI: 0.01, 0.05 for CDI-3.5). Higher fruit and vegetables or fish intake and lower pork-meat products intake were related to higher CDI-3.5 scores (β = 0.03; 95% CI: 0.01, 0.05 for fruit and vegetables; β = 0.03; 95% CI: 0.01, 0.05 for fish; and β = -0.02; 95% CI: -0.04, 0.00 for pork-meat products). A higher score on the processed food pattern was associated with poorer neurodevelopmental score at 1 y (β = -0.05; 95% CI: -0.06, -0.03).

CONCLUSIONS

Higher diet quality during pregnancy was associated with higher parent-reported neurodevelopmental scores in early childhood. The negative association of pork-meat products consumption with early neurodevelopmental scores needs to be further confirmed.

Prevalence of Food Allergy in France up to 5.5 Years of Age: Results from the ELFE Cohort

Background: In France, updated data on food allergies (FAs) are lacking, despite the need for efficient FA management and prevention. This study aimed to evaluate the prevalence of FAs in children in France, describe the most common allergens and determine the prevalence of atopic diseases in children with FAs. Methods: The ELFE study comprises a French nationwide birth cohort, including 18,329 children born in 2011. FAs were assessed by parental reports of food avoidance based on medical advice related to FAs, provided at 2 months and 2, 3.5 and 5.5 years of age. Data regarding FAs were available for 16,400 children. Data were weighted to account for selection and attrition bias. Results: From birth to 5.5 years of age, FAs were reported for 5.94% (95% CI: 5.54–6.34) children. Milk was the most common allergen, followed by egg, peanut, exotic fruits, tree nuts, gluten and fish. Among children with FAs, 20.5% had an allergy to at least two different groups of allergens; 71% reported eczema at least once before 5.5 years of age; 24.4% reported incidence of asthma; and 42.3% reported incidence of allergic rhinitis or conjunctivitis. Conclusion: In France, the prevalence of FAs in children up to 5.5 years of age is approximately 6%. It was demonstrated that 1 in 5 children with allergies had multiple FAs.

Organic Food Consumption During the Complementary Feeding Period and Respiratory or Allergic Diseases Up to Age 5.5 Years in the ELFE Cohort

Objectives: To assess (1) whether a history of allergy is associated with feeding with organic foods (OFs) during the complementary feeding period and (2) whether OF consumption in infancy is related to the incidence of respiratory and allergic diseases up to age 5.5 years.

Study Design: Analyses involved more than 8,000 children from the nationwide Étude Longitudinale Française depuis l'Enfance (ELFE) birth cohort. Associations between family or infant history of allergy and frequency of OF consumption during the complementary feeding period were assessed with multinomial logistic regression. Associations between OF consumption in infancy and respiratory or allergic diseases between age 1 and 5.5 years were assessed with logistic regression.

Results: A family history of allergy or cow's milk protein allergy at age 2 months was strongly and positively related to feeding with OF during the complementary feeding period. Feeding with OF during the complementary feeding period was not related to respiratory diseases or eczema up to age 5.5 years. Compared to infrequent consumption of both organic and commercial complementary foods, frequent OF consumption without commercial complementary foods was associated with a higher risk of food allergy, whereas frequent commercial complementary food consumption without OF use was associated with a lower risk of food allergy.

Conclusions: This study suggests that a history of allergy strongly affects feeding with OF during the complementary feeding period. However, OF consumption was not associated with reduced odds of food allergy later in childhood but could be associated with increased odds, which should be examined more deeply.

Diet during pregnancy: Influence of social characteristics and migration in the ELFE cohort

Better adherence to dietary guidelines during pregnancy is supposed to result in healthier perinatal outcomes. We aim to characterize the diets of pregnant women by hypothesis‐driven and exploratory approaches and describe potential social determinants. Analyses included 12 048 mothers from the French nationwide ELFE birth cohort. Dietary intake over the last three months of the pregnancy was assessed by a food frequency questionnaire. Two hypothesis‐driven scores (the Diet Quality score, based on benchmarks derived from the National Health and Nutrition Program Guidelines, and the PANDiet score, based on nutrient intake) were calculated. Exploratory dietary patterns were also identified by principal component analysis. Multiple linear regressions were used to assess associations of maternal social characteristics with dietary patterns, accounting for the possible effect modification by their migration status. Five dietary patterns were identified: the Western, Balanced, Bread and toppings, Processed products, and Milk and breakfast cereals. Younger maternal age, single motherhood, unemployment and the presence of older children in the household were related to a suboptimal diet during pregnancy. The less acculturated the women were, the healthier and less processed their diets were, independent of their socio‐economic position. Several social determinants of the quality of women's diets were however moderated by their migration status. These findings shed light on the relations between indicators of social vulnerability, such as single motherhood and unemployment, and poorer diet quality. Given the reduced diet quality that accompanies the acculturation process, it is of paramount importance to identify the specific factors or obstacles that affect migrant women in maintaining their diet quality advantage over the majority population.

Association between perinatal factors, genetic susceptibility to obesity and age at adiposity rebound in children of the EDEN mother-child cohort

BACKGROUND

Early adiposity rebound (AR) has been associated with increased risk of overweight or obesity in adulthood. However, little is known about early predictors of age at AR. We aimed to study the role of perinatal factors and genetic susceptibility to obesity in the kinetics of AR.

METHODS

Body mass index (BMI) curves were modelled by using mixed-effects cubic models, and age at AR was estimated for 1415 children of the EDEN mother-child cohort study. A combined obesity risk-allele score was calculated from genotypes for 27 variants identified by genome-wide association studies of adult BMI. Perinatal factors of interest were maternal age at delivery, parental education, parental BMI, gestational weight gain, maternal smoking during pregnancy, and newborn characteristics (sex, prematurity, and birth weight). We used a hierarchical level approach with multivariable linear regression model to investigate the association between these factors, obesity risk-allele score, and age at AR.

RESULTS

A higher genetic susceptibility to obesity score was associated with an earlier age at AR. At the most distal level of the hierarchical model, maternal and paternal educational levels were positively associated with age at AR. Children born to parents with higher BMI were more likely to exhibit earlier age at AR. In addition, higher gestational weight gain was related to earlier age at AR. For children born small for gestational age, the average age at AR was 88 [±39] days lower than for children born appropriate for gestational age and 91 [±56] days lower than for children born large for gestational age.

CONCLUSION

The timing of AR seems to be an early childhood manifestation of the genetic susceptibility to adult obesity. We further identified low birth weight and gestational weight gain as novel predictors of early AR, highlighting the role of the intrauterine environment in the kinetics of adiposity.

Breastfeeding initiation or duration and longitudinal patterns of infections up to 2 years and skin rash and respiratory symptoms up to 8 years in the EDEN mother-child cohort

This paper aimed to examine the effect of breastfeeding on longitudinal patterns of common infections up to 2 years and respiratory symptoms up to 8 years. To assess the incidence and reoccurrence of infections and allergic symptoms in the first years of life among 1,603 children from the EDEN mother–child cohort, distinct longitudinal patterns of infectious diseases as well as skin rash and respiratory symptoms were identified by group‐based trajectory modelling. To characterize infections, we considered the parent‐reported number of cold/nasopharyngitis and diarrhoea from birth to 12 months and otitis and bronchitis/bronchiolitis from birth to 2 years. To characterize allergy‐related symptoms, we considered the parent‐reported occurrence of wheezing and skin rash from 8 months to 8 years and asthma from 2 to 8 years. Then associations between breastfeeding and these longitudinal patterns were assessed through adjusted multinomial logistic regression. Compared with never‐breastfed infants, ever‐breastfed infants were at a lower risk of diarrhoea events in early infancy as well as infrequent events of bronchitis/bronchiolitis throughout infancy. Only predominant breastfeeding duration was related to frequent events of bronchitis/bronchiolitis and infrequent events of otitis. We found no significant protective effect of breastfeeding on longitudinal patterns of cold/nasopharyngitis, skin rash, or respiratory symptoms. For an infant population with a short breastfeeding duration, on average, our study confirmed a protective effect of breastfeeding on diarrhoea events in early infancy, infrequent bronchitis/bronchiolitis and, to a lesser extent, infrequent otitis events up to 2 years but not on other infections, skin rash, or respiratory symptoms4.

In an infant population with a short breastfeeding duration and using longitudinal patterns of infection, skin rash and respiratory symptoms, on average, our study confirmed a protective effect of breastfeeding on diarrhea events in early infancy, infrequent bronchitis/bronchiolitis and, to a lesser extent,infrequent otitis events up to 2 years but not on cold/ nasopharyngitis, skin rash or respiratory symptoms.

Sleep habits and sleep characteristics at 1 year-old in the ELFE birth cohort study

Key messages

French infants present better sleep characteristics than their counterparts. Most sleep habits associated with poor sleep are accessible to prevention.

Which modifiable prenatal factors mediate the relation between socio-economic position and a child's weight and length at birth?

Although several studies have shown a positive association between socio-economic position and size at birth, not enough is known about the modifiable factors that may be involved. We aimed to investigate whether maternal prepregnancy body mass index (BMI), smoking, diet, and depression during pregnancy mediate the positive association between maternal education and birth size. Weight and length z-scores specific for gestational age and sex were calculated for 1,500 children from the EDEN mother-child cohort. A mediation analysis of the associations between maternal education and birth size was conducted with a counterfactual method, adjusted for recruitment centre, parity, maternal height, and age. In the comparison of children of mothers with low versus intermediate education levels, maternal smoking during pregnancy explained 52% of the total effect of education on birth weight. Similar findings were observed with birth length z-score (37%). The comparison of children of mothers with high versus intermediate education levels yielded a non-significant total effect, which masked opposite mediating effects by maternal BMI and smoking during pregnancy on both birth weight and length. Prepregnancy BMI and maternal smoking during pregnancy mediate the positive association between maternal education and birth weight and length z-scores. These mediators, however, act in opposite directions, thereby masking the extent to which healthy prenatal growth is socially differentiated.

Maternity or parental leave and breastfeeding duration: Results from the ELFE cohort

Previous studies have shown a high level of noncompliance with recommendations on breastfeeding duration, especially in France. The objective was to describe the association between breastfeeding initiation and duration and the statutory duration of postnatal maternity leave, the gap between the end of legal maternity leave and the mother's return to work, and maternal working time during the first year post-partum. Analyses were based on 8,009 infants from the French nationwide ELFE cohort. We assessed the association with breastfeeding initiation by using logistic regression and, among breastfeeding women, with categories of breastfeeding duration by using multinomial logistic regression. Among primiparous women, both postponing return to work for at least 3 weeks after statutory postnatal maternity leave (as compared with returning to work at the end of the statutory period) and working less than full-time at 1 year post-partum (as compared with full-time) were related to higher prevalence of breastfeeding initiation. Among women giving birth to their first or second child, postponing the return to work until at least 15 weeks was related to a higher prevalence of long breastfeeding duration (at least 6 months) as compared with intermediate duration (3 to <6 months). Working part-time was also positively related to breastfeeding duration. Among women giving birth to their third child or more, working characteristics were less strongly related to breastfeeding duration. These results support extending maternity leave or working time arrangements to encourage initiation and longer duration of breastfeeding.

Social Inequalities in Prenatal Folic Acid Supplementation: Results from the ELFE Cohort

Most professional and international organizations recommend folic acid supplementation for women planning pregnancy. Various studies have shown high levels of non-compliance with this recommendation. This study aimed to identify sociodemographic characteristics related to this compliance. The analyses were based on 16,809 women from the French nationwide ELFE cohort (Etude Longitudinale Française depuis l’Enfance). Folic acid supplementation was assessed at delivery, and sociodemographic characteristics were collected at two months postpartum. The association between sociodemographic characteristics and compliance with recommendations on folic acid supplementation (no supplementation, periconceptional supplementation, and supplementation only after the periconceptional period) was examined using multivariate multinomial logistic regression. Only 26% of French women received folic acid supplementation during the periconceptional period, 10% of women received supplementation after the periconceptional period, and 64% received no supplementation. Young maternal age, low education level, low family income, multiparity, single parenthood, maternal unemployment, maternal overweight, and smoking during pregnancy were related to lower likelihood of folic acid supplementation during the periconceptional period compared to no supplementation. These associations were not explained by unplanned pregnancy. Immigrant and underweight women were more likely to receive folic acid supplementation after the periconceptional period. Our study confirms great social disparities in France regarding the compliance with the recommendations on folic acid supplementation.

Association between genetic obesity susceptibility and mother-reported eating behaviour in children up to 5 years

BACKGROUND

Many genetic polymorphisms identified by genome-wide association studies for adult body mass index (BMI) have been suggested to regulate food intake.

OBJECTIVE

The objective was to study the associations between a genetic obesity risk score, appetitive traits, and growth of children up to age 5 years, with a longitudinal design.

METHODS

In 1142 children from the Etude des Déterminants pre et post natals de la santé de l'ENfant (EDEN) birth cohort, a combined obesity risk-allele score (BMI genetic risk score [GRS]) was related to appetitive traits (energy intake up to 12 mo, a single item on appetite from 4 mo to 3 y, a validated appetite score at 5 y) using Poisson regressions with robust standard errors. The potential mediation of appetitive traits on the association between BMI-GRS and growth was assessed by the Sobel test.

RESULTS

Children with a high BMI-GRS were more likely to have high energy intake at 1 year and high appetite at 2 and 5 years. High energy intake in infancy and high appetite from 1 year were related to higher subsequent BMI. High 2-year appetite seemed to partially mediate the associations between BMI-GRS and BMI from 2 to 5 years (all P ≤ 0.05).

CONCLUSIONS

Genetic susceptibility to childhood obesity seems to be partially explained by appetitive traits in infancy, followed by an early childhood rise in BMI.

The International Childhood Cancer Cohort Consortium (I4C): A research platform of prospective cohorts for studying the aetiology of childhood cancers

BACKGROUND

Childhood cancer is a rare but leading cause of morbidity and mortality. Established risk factors, accounting for <10% of incidence, have been identified primarily from case-control studies. However, recall, selection and other potential biases impact interpretations particularly, for modest associations. A consortium of pregnancy and birth cohorts (I4C) was established to utilise prospective, pre-diagnostic exposure assessments and biological samples.

METHODS

Eligibility criteria, follow-up methods and identification of paediatric cancer cases are described for cohorts currently participating or planning future participation. Also described are exposure assessments, harmonisation methods, biological samples potentially available for I4C research, the role of the I4C data and biospecimen coordinating centres and statistical approaches used in the pooled analyses.

RESULTS

Currently, six cohorts recruited over six decades (1950s-2000s) contribute data on 388 120 mother-child pairs. Nine new cohorts from seven countries are anticipated to contribute data on 627 500 additional projected mother-child pairs within 5 years. Harmonised data currently includes over 20 "core" variables, with notable variability in mother/child characteristics within and across cohorts, reflecting in part, secular changes in pregnancy and birth characteristics over the decades.

CONCLUSIONS

The I4C is the first cohort consortium to have published findings on paediatric cancer using harmonised variables across six pregnancy/birth cohorts. Projected increases in sample size, expanding sources of exposure data (eg, linkages to environmental and administrative databases), incorporation of biological measures to clarify exposures and underlying molecular mechanisms and forthcoming joint efforts to complement case-control studies offer the potential for breakthroughs in paediatric cancer aetiologic research.

Wheezing phenotypes and risk factors in early life: The ELFE cohort

Objective

Different phenotypes of wheezing have been described to date but not in early life. We aim to describe wheezing phenotypes between the ages of two months and one year, and assess risk factors associated with these wheezing phenotypes in a large birth cohort.

Methods

We studied 18,041 infants from the ELFE (French Longitudinal Study of Children) birth cohort. Parents reported wheezing and respiratory symptoms at two and 12 months, and answered a complete questionnaire (exposure during pregnancy, parental allergy).

Results

Children with no symptoms (controls) accounted for 77.2%, 2.1% had had wheezing at two months but no wheezing at one year (intermittent), 2.4% had persistent wheezing, while 18.3% had incident wheezing at one year. Comparing persistent wheezing to controls showed that having one sibling (ORa = 2.19) or 2 siblings (ORa = 2.23) compared to none, nocturnal cough (OR = 5.2), respiratory distress (OR = 4.1) and excess bronchial secretions (OR = 3.47) at two months, reflux in the child at 2 months (OR = 1.55), maternal history of asthma (OR = 1.46) and maternal smoking during pregnancy (OR = 1.57) were significantly associated with persistent wheezing. These same factors, along with cutaneous rash in the child at 2 months (OR = 1.13) and paternal history of asthma (OR = 1.32) were significantly associated with increased odds of incident wheezing. Having one sibling (ORa = 1.9) compared to none, nocturnal cough at 2 months (OR = 1.76) and excess bronchial secretions at 2 months (OR = 1.65) were significantly associated with persistent compared to intermittent wheezing.

Conclusion

Respiratory symptoms (cough, respiratory distress, and excessive bronchial secretion) were significantly associated with a high risk of persistent wheezing at one year. Smoking exposure during pregnancy was also a risk factor for persistent and incident wheezing.

Use of infant formula in the ELFE study: The association with social and health-related factors

Breastfeeding is recommended until 6 months of age, but a wide range of infant formula is available for nonbreastfed or partially breastfed infants. Our aim was to describe infant formula selection and to examine social- and health-related factors associated with this selection. Analyses were based on 13,291 infants from the French national birth cohort Etude Longitudinale Française depuis l'Enfance. Infant diet was assessed at Month 2 by phone interview and monthly from Months 3 to 10 via internet/paper questionnaires. Infant formulas were categorized in 6 groups: extensively or partially hydrolysed, regular with or without prebiotics/probiotics, and thickened with or without prebiotics/probiotics. Associations between type of infant formula used at 2 months and family or infant characteristics were assessed by multinomial logistic regressions. At Month 2, 58.1% of formula-fed infants were fed with formula enriched in prebiotics/probiotics, 31.5% with thickened formula, and 1.4% with extensively hydrolysed formula. The proportion of formula-fed infants increased regularly, but the type of infant formula used was fairly stable between 2 and 10 months. At Month 2, extensively hydrolysed formulas were more likely to be used in infants with diarrhoea or regurgitation problems. Partially hydrolysed formulas were more often used in families with high income, with a history of allergy, or with infants with regurgitation issues. Thickened formulas were used more with boys, preterm infants, infants with regurgitation issues, or in cases of early maternal return to work. The main factors related to the selection of infant formula were family and infant health-related ones.

Maternal weight prior and during pregnancy and offspring's BMI and adiposity at 5-6 years in the EDEN mother-child cohort

BACKGROUND

Beyond pre-pregnancy BMI, maternal weight change before and during pregnancy may also affect offspring adiposity.

OBJECTIVE

To investigate the relationship between maternal weight history before and during pregnancy with children's adiposity at 5-6 years.

METHODS

In 1069 mother-child dyads from the EDEN Cohort, we examined by linear regression the associations of children's BMI, fat mass and abdominal adiposity at 5-6 years with maternal pre-pregnancy BMI, pre-pregnancy average yearly weight change from age 20 and gestational weight gain. The shapes of relationships were investigated using splines and polynomial functions were tested.

RESULTS

Children's BMI and adiposity parameters were positively associated with maternal pre-pregnancy BMI, but these relationships were mainly seen in thin mothers, with no substantial variation for maternal BMI ranging from 22 to 35 kg/m² . Gestational weight gain was positively associated with children's BMI Z-score, but again more so in thin mothers. We found no association with pre-pregnancy weight change.

CONCLUSIONS

Before the adiposity rebound, maternal pre-pregnancy thinness explains most of the relationship with children's BMI. The relationship may emerge at older ages in children of overweight and obese mothers, and this latency may be an obstacle to early prevention.

Influence of infant feeding patterns over the first year of life on growth from birth to 5 years

OBJECTIVES

As early-life feeding experiences may influence later health, we aimed to examine relations between feeding patterns over the first year of life and child's growth in the first 5 years of life.

METHODS

Our analysis included 1022 children from the EDEN mother-child cohort. Three feeding patterns were previously identified, i.e. 'Later dairy products introduction and use of ready-prepared baby foods' (pattern-1), 'Long breastfeeding, later main meal food introduction and use of home-made foods' (pattern-2) and 'Use of ready-prepared adult foods' (pattern-3). Associations between the feeding patterns and growth [weight, height and body mass index {BMI}] were analysed by multivariable linear regressions. Anthropometric changes were assessed by the final value adjusted for the initial value.

RESULTS

Even though infant feeding patterns were not related to anthropometric measurements at 1, 3 and 5 years, high scores on pattern-1 were associated with higher 1-3 years weight and height changes. High scores on pattern-2 were related to lower 0-1 year weight and height changes, higher 1-5 years weight and height changes but not to BMI changes, after controlling for a wide range of potential confounding variables including parental BMI. Scores on pattern-3 were not significantly related to growth. Additional adjustment for breastfeeding duration reduced the strength of the associations between pattern-2 and growth but not those between pattern-1 and height growth.

CONCLUSION

Our findings emphasize the relevance of considering infant feeding patterns including breastfeeding duration, age of complementary foods introduction as well as type of foods used when examining effects of early infant feeding practices on later health. © 2017 World Obesity Federation.

[Silhouettes at different age of life: Retrospective appreciation of corpulence and his impact on prevalence of hypertension at 60years]

PURPOSE OF THE STUDY

In epidemiological studies, recall of weight and height are not readily available at different ages of life. In order to improve the knowledge of the weight history, Sörensen et al. in 1983, developed a tool from silhouettes allowing an individual to evaluate his corpulence at different ages of life. Validity studies showed that measured weight and size were correlated to 80% in the reported silhouette. Studies have also shown that silhouettes are a good way to trace the weight history in an individual's life. Very few epidemiological studies have used this tool. A French study revealed a decrease of the risk of breast cancer in obese girls between the age of 8 and adolescence. Another study showed that a low birth weight or a thin silhouette before adulthood was associated with an increased risk of diabetes. On the basis of these findings, it was interesting to evaluate the relationship between the silhouette at 20years and the risk of hypertension at the age of 60years.

RESULTS

It was shown that the prevalence of hypertension at age 60 was higher among obese subjects at 20years than among thin subjects (45.3% vs 36.7% (P<0.05).

CONCLUSION

The classification between slimness and obesity is relevant using this tool. The history of corpulence is an important element to consider in the determinants of pathology, especially in hypertension.

[Early determinants of obesity]

The prevalence of childhood obesity has increased dramatically in the second half of the 20th century even in children before the age of 5 years. Many factors may interfere with early development, from the prenatal period to the first two years of life, and modulate susceptibility to subsequent obesity. Regarding the prenatal period, maternal BMI before pregnancy is a factor associated with adult obesity in a very reproducible way. Many studies are also consistent for gestational maternal weight gain and maternal smoking during pregnancy, after adjustment for major potential confounders. More recently, a meta-analysis concluded that caesarean delivery is also a risk marker. For the post natal period, the marker most consistently associated with adult obesity is rapid weight gain during the first months of life. Most studies are negative for breastfeeding. Advances in the genetics of obesity, epigenetics and new knowledge on intestinal microbiota should help decipher the mechanisms behind these associations. Many of these early markers become more frequent during the second half of the 20th century and they may have feed the obesity epidemic in children.

Developmental determinants in non-communicable chronic diseases and ageing

Prenatal and peri-natal events play a fundamental role in health, development of diseases and ageing (Developmental Origins of Health and Disease (DOHaD)). Research on the determinants of active and healthy ageing is a priority to: (i) inform strategies for reducing societal and individual costs of an ageing population and (ii) develop effective novel prevention strategies. It is important to compare the trajectories of respiratory diseases with those of other chronic diseases.

Birth weight and eating behaviors of young children

OBJECTIVE

To evaluate the relationships prospectively between birth weight (standardized for gestational age) and problematic eating behaviors, as reported by the parents, at different ages in 3 birth cohorts: Generation XXI (Portugal), Avon Longitudinal Study of Parents and Children (United Kingdom), and Etude des Déterminants pre et postnatals précoces du développement et de la santé de l'ENfant study (France) - HabEat project. We also aimed to explore the effect of child's current body mass index (BMI) in these relationships.

STUDY DESIGN

Problematic eating behaviors were assessed at 4-6, 12-15, 24, and 48-54 months, based on caregiver's perception. Children born small, appropriate, and large for gestational age were defined based on sex-specific Kramer growth references. Associations were tested by logistic regression (OR, 95% CI) adjusted for maternal age, education, BMI, smoking, breastfeeding duration, older siblings, birth type and, in a second step, for child's current BMI World Health Organization z-score.

RESULTS

Parents of children born small for gestational age (compared with appropriate gestational age) reported more often feeding difficulties and poor eating patterns (eating small quantities or needing stimulation to eat) at 4-6 months (Generation XXI: OR 2.02, 95% CI 1.40-2.94; Avon Longitudinal Study of Parents and Children: OR 1.36, 95% CI 1.14-1.62; Etude des Déterminants pre et postnatals précoces du développement et de la santé de l'ENfant OR 3.24, 95% CI 1.50-6.96), but this effect was weaker at older ages. Overall, the effects decreased, after adjustment for child's BMI, but remained significant.

CONCLUSIONS

Low birth weight for gestational age was related to later difficulty in eating behaviors, primarily in the first 4-6 months.

Does consideration of larger study areas yield more accurate estimates of air pollution health effects? An illustration of the bias-variance trade-off in air pollution epidemiology

BACKGROUND

Spatially-resolved air pollution models can be developed in large areas. The resulting increased exposure contrasts and population size offer opportunities to better characterize the effect of atmospheric pollutants on respiratory health. However the heterogeneity of these areas may also enhance the potential for confounding. We aimed to discuss some analytical approaches to handle this trade-off.

METHODS

We modeled NO2 and PM10 concentrations at the home addresses of 1082 pregnant mothers from EDEN cohort living in and around urban areas, using ADMS dispersion model. Simulations were performed to identify the best strategy to limit confounding by unmeasured factors varying with area type. We examined the relation between modeled concentrations and respiratory health in infants using regression models with and without adjustment or interaction terms with area type.

RESULTS

Simulations indicated that adjustment for area limited the bias due to unmeasured confounders varying with area at the costs of a slight decrease in statistical power. In our cohort, rural and urban areas differed for air pollution levels and for many factors associated with respiratory health and exposure. Area tended to modify effect measures of air pollution on respiratory health.

CONCLUSIONS

Increasing the size of the study area also increases the potential for residual confounding. Our simulations suggest that adjusting for type of area is a good option to limit residual confounding due to area-associated factors without restricting the area size. Other statistical approaches developed in the field of spatial epidemiology are an alternative to control for poorly-measured spatially-varying confounders.

The influence of early feeding practices on fruit and vegetable intake among preschool children in 4 European birth cohorts

BACKGROUND

Fruit and vegetable intake in children remains below recommendations in many countries. The long-term effects of early parental feeding practices on fruit and vegetable intake are not clearly established.

OBJECTIVE

The purpose of the current study was to examine whether early feeding practices influence later fruit and vegetable intake in preschool children.

DESIGN

The study used data from 4 European cohorts: the British Avon Longitudinal Study of Parents and Children (ALSPAC), the French Etude des Déterminants pre et postnatals de la santé et du développement de l'Enfant study, the Portuguese Generation XXI Birth Cohort, and the Greek EuroPrevall study. Fruit and vegetable intake was assessed in each cohort by food-frequency questionnaire. Associations between early feeding practices, such as breastfeeding and timing of complementary feeding, and fruit and/or vegetable intake in 2-4-y-old children were tested by using logistic regressions, separately in each cohort, after adjustment for infant's age and sex and maternal age, educational level, smoking during pregnancy, and maternal fruit and vegetable intake.

RESULTS

Large differences in early feeding practices were highlighted across the 4 European cohorts with longer breastfeeding duration in the Generation XXI Birth Cohort and earlier introduction to complementary foods in ALSPAC. Longer breastfeeding duration was consistently related to higher fruit and vegetable intake in young children, whereas the associations with age of introduction to fruit and vegetable intake were weaker and less consistent across the cohorts. Mothers' fruit and vegetable intake (available in 3 of the cohorts) did not substantially attenuate the relation with breastfeeding duration.

CONCLUSION

The concordant positive association between breastfeeding duration and fruit and vegetable intake in different cultural contexts favors an independent specific effect.

Blood microbiota dysbiosis is associated with the onset of cardiovascular events in a large general population: the D.E.S.I.R. study

Aim

We recently described a human blood microbiome and a connection between this microbiome and the onset of diabetes. The aim of the current study was to assess the association between blood microbiota and incident cardiovascular disease.

Methods and Results

D.E.S.I.R. is a longitudinal study with the primary aim of describing the natural history of the metabolic syndrome and its complications. Participants were evaluated at inclusion and at 3-, 6-, and 9-yearly follow-up visits. The 16S ribosomal DNA bacterial gene sequence, that is common to the vast majority of bacteria (Eubac) and a sequence that mostly represents Proteobacteria (Pbac), were measured in blood collected at baseline from 3936 participants. 73 incident cases of acute cardiovascular events, including 30 myocardial infarctions were recorded. Eubac was positively correlated with Pbac (r = 0.59; P<0.0001). In those destined to have cardiovascular complications, Eubac was lower (0.14±0.26 vs 0.12±0.29 ng/µl; P = 0.02) whereas a non significant increase in Pbac was observed. In multivariate Cox analysis, Eubac was inversely correlated with the onset of cardiovascular complications, (hazards ratio 0.50 95% CI 0.35–0.70) whereas Pbac (1.56, 95%CI 1.12–2.15) was directly correlated.

Conclusion

Pbac and Eubac were shown to be independent markers of the risk of cardiovascular disease. This finding is evidence for the new concept of the role played by blood microbiota dysbiosis on atherothrombotic disease. This concept may help to elucidate the relation between bacteria and cardiovascular disease.

Specific role of maternal weight change in the first trimester of pregnancy on birth size

The specific role of weight change in the first weeks of gestation in fetal growth has not been fully explored in humans. Our aims were to investigate: (1) the specific association between weight change in the first trimester of pregnancy (WCT1) and size at birth in term pregnancies; and (2) the role of placental weight in this relationship. From 2002 women included in the French EDEN study, 1744 mother-child pairs reached term, had pre-pregnancy weight available and at least five measures of weight in pregnancy. We extrapolated women's weight at each week of gestation with a three-degree polynomial model and estimated weight change during each trimester of gestation. We used a multivariate linear model to investigate the associations between WCT1 and birth size after taking into account potential confounders (age, parity, BMI, tobacco use, educational level, length of gestation, newborn gender, weight change after the first trimester and centre of study). Then, we performed path analysis to investigate whether the relation between WCT1 and birth size could be mediated by placental weight. After taking into account weight gain in later gestation, WCT1 was positively associated with birthweight. Results of path analysis showed that there was no direct association between WCT1 and birth size, but that this association was mediated by placental weight. Weight change during the first weeks of pregnancy may impact on fetal growth independently of weight change later in pregnancy through its effects on placental growth and function.

Pre-pregnancy body mass index and weight gain during pregnancy: relations with gestational diabetes and hypertension, and birth outcomes

To study the relationship between pre-pregnancy body mass index (BMI) and weight gain during pregnancy with pregnancy and birth outcomes, with a focus on gestational diabetes and hypertension and their role in the association with fetal growth. We studied 1,884 mothers and offspring from the Eden mother-child cohort. Weight before pregnancy (W1) and weight after delivery (W2) were collected and we calculated BMI and net gestational weight gain (netGWG = (W2 - W1)/(weeks of gestation)). Gestational diabetes, hypertension gestational age and birth weight were collected. We used multivariate linear or logistic models to study the association between BMI, netGWG and pregnancy and birth outcomes, adjusting for center, maternal age and height, parity and average number of cigarettes smoked per day during pregnancy. High BMI was more strongly related to the risk of giving birth to a large-for-gestational-age (LGA) baby than high netGWG (odds ratio OR [95% CI] of 3.23 [1.86-5.60] and 1.61 [0.91-2.85], respectively). However, after excluding mothers with gestational diabetes or hypertension the ORs for LGA, respectively weakened (OR 2.57 [1.29-5.13]) for obese women and strengthened for high netGWG (OR 2.08 [1.14-3.80]). Low in comparison to normal netGWG had an OR of 2.18 [1.20-3.99] for pre-term birth, which became stronger after accounting for blood pressure and glucose disorders (OR 2.70 [1.37-5.34]). Higher net gestational weight gain was significantly associated with an increased risk of LGA only after accounting for blood pressure and glucose disorders. High gestational weight gain should not be neglected in regard to risk of LGA in women without apparent risk factors.

Influence of fetal and parental factors on intrauterine growth measurements: results of the EDEN mother-child cohort

OBJECTIVE

In small-for-gestational-age neonates, parental and fetal characteristics can be used to distinguish between constitutionally small size and growth restriction, which is associated with a higher risk of morbidity and mortality. The aim of this study was to quantify relationships of parental and fetal characteristics with fetal ultrasound measurements.

METHODS

The EDEN mother-child cohort included 2002 pregnant women with singleton pregnancies attending one of two university hospitals. Data from two routine ultrasound examinations for fetal biometry were recorded, at 20-25 and 30-35 weeks of gestation. Biparietal diameter (BPD), head circumference (HC), femur length (FL), abdominal circumference (AC) and estimated fetal weight (EFW) were studied as a function of prepregnancy maternal body mass index (BMI), maternal height, paternal height, fetal sex and gestational age.

RESULTS

Data were obtained at the first scan from 1833 women and at the second scan from 1752 women. Parental anthropometric characteristics were significantly associated with ultrasound measurements at both scans. Maternal BMI was more strongly associated with AC and EFW, whereas both maternal and paternal height were more strongly associated with FL. An association was also found between fetal sex and all ultrasound measurements other than FL.

CONCLUSION

Maternal and paternal anthropometric characteristics are significantly associated with ultrasound measurements in mid to late pregnancy. These relationships provide support for the use of these characteristics in ultrasound fetal size reference charts.

Involvement of tissue bacteria in the onset of diabetes in humans: evidence for a concept

AIMS/HYPOTHESIS

Evidence suggests that bacterial components in blood could play an early role in events leading to diabetes. To test this hypothesis, we studied the capacity of a broadly specific bacterial marker (16S rDNA) to predict the onset of diabetes and obesity in a general population.

METHODS

Data from an Epidemiological Study on the Insulin Resistance Syndrome (D.E.S.I.R.) is a longitudinal study with the primary aim of describing the history of the metabolic syndrome. The 16S rDNA concentration was measured in blood at baseline and its relationship with incident diabetes and obesity over 9 years of follow-up was assessed. In addition, in a nested case-control study in which participants later developed diabetes, bacterial phylotypes present in blood were identified by pyrosequencing of the overall 16S rDNA gene content.

RESULTS

We analysed 3,280 participants without diabetes or obesity at baseline. The 16S rDNA concentration was higher in those destined to have diabetes. No difference was observed regarding obesity. However, the 16S rDNA concentration was higher in those who had abdominal adiposity at the end of follow-up. The adjusted OR (95% CIs) for incident diabetes and for abdominal adiposity were 1.35 (1.11, 1.60), p = 0.002 and 1.18 (1.03, 1.34), p = 0.01, respectively. Moreover, pyrosequencing analyses showed that participants destined to have diabetes and the controls shared a core blood microbiota, mostly composed of the Proteobacteria phylum (85-90%).

CONCLUSIONS/INTERPRETATION

16S rDNA was shown to be an independent marker of the risk of diabetes. These findings are evidence for the concept that tissue bacteria are involved in the onset of diabetes in humans.

A Pilot Study of the ELFE Longitudinal Cohort: Feasibility and Preliminary Evaluation of Biological Collection

Etude Longitudinale Française depuis l'Enfance (ELFE) will be a national French cohort of 20,000 children followed from birth to adulthood. Biological samples will be taken at birth to evaluate the fetal exposition to several substances. A pilot study was carried out in October 2007 to test the preanalytical factors that affected sample quality. A variety of fractions were collected by the midwife after delivery from different blood collection tubes. Options in the collection process were 2 daily transports of samples, centralized and standardized processing methodology, and storage of multiple aliquots in liquid nitrogen or at -80°C. We analyzed preanalytical factors that could have affected coagulation and then soluble CD40 Ligand (sCD40L) as a quality control tool for serum quality. Cord blood and urine were collected from 82% and 84% of women, respectively, who agreed to be followed up in the ELFE project. The use of syringe was the main factor correlated with coagulation (relative risk: 2.79 [1.47; 5.31], P<0.01). Maternity unit status was also associated with coagulation (RR: 1.48 [1.03; 2.13] in a private maternity unit vs. a public maternity) as well as time between collection and centrifugation (RR 1.03 [1; 1.07] when time between collection and centrifugation increases from 1 h). There were no extremely low sCD40L values indicating extreme exposures to room temperatures. This first evaluation study allowed us to stress the importance of carefully recording all potentially critical preanalytical variables that might be used at a large-scale level.

Clinical outcomes after insulin initiation in patients with type 2 diabetes: 6-month data from the INSTIGATE observational study in five European countries

OBJECTIVES

To examine insulin regimens and factors that affect glycaemic control at 6 months after initiation of insulin therapy in patients with type 2 diabetes mellitus.

RESEARCH DESIGN AND METHODS

Information on patients requiring insulin initiation as part of usual care was collected in a prospective, observational, open-label study in five European countries. Univariate and multiple regression analyses were used to investigate factors associated with HbA1c achieved at 6 months.

RESULTS

Mean HbA1c for all patients at baseline was 9.6 ± 1.8%. Long/intermediate-acting insulin only was most commonly initiated in France and Spain, while long/intermediate or pre-mixed formulations were initiated in Greece and UK. This was consistent with guidelines used in those countries and there was little change in insulin regimen at 6 months in these countries. In Germany, short-acting insulin only was favoured at baseline and there was a shift towards basal/bolus regimens at 6 months, which reflected the local guidelines for insulin initiation in Germany. Mean HbA1c reduction was greatest in Germany (-2.3%), which was the only country to achieve a mean of <7% at 6 months. In all countries, HbA1c achieved at 6 months was associated with baseline HbA1c. Differences between countries were seen for influence of factors such as BMI, duration of diabetes, insulin regimen, insulin dose and number of oral anti-diabetes drugs on HbA1c achieved. Explained variability for the factors ranged from 5.6% to 22.9%.

CONCLUSIONS

Differences in insulin regimen were observed between countries, and appeared to reflect the guidelines and treatment regimens used.

Discordant time trends in maternal body size and offspring birthweight of term deliveries in France between 1972 and 2003: data from the French National Perinatal Surveys

We investigated time trends in maternal weight before and during pregnancy and in infant birthweight in France, from 1972 to 2003, using data on singleton live term births from the representative National Perinatal Surveys of 1972, 1981, 1995, 1998 and 2003 (n=8,664, 4,494, 11,445, 12,006, 12,692, respectively). Mothers were interviewed a few days after delivery and data on delivery and the newborn were extracted from hospital records. Maternal prepregnancy weight, height, body mass index and pregnancy weight gain all increased from 1972 to 2003; however, birthweight did not show a parallel trend. After taking gestational age, maternal age, parity, country of origin, newborn gender and maternal smoking during pregnancy into account, mean birthweight increased between 1972 and 1995 but decreased thereafter and, consistently, there was an increase in small-for-gestational age (SGA) and a decrease in large-for-gestational age newborns. Further adjustment for induced delivery, an indicator of obstetric practice, did not change the results. A similar variation has been observed very recently in the US and in Germany. Further research is needed to identify the factors responsible for these discordant changes and especially the factors responsible for the recent increase in SGA since this has been shown to be associated with poorer health in later life.

Parental body size and early weight and height growth velocities in their offspring

BACKGROUND

Whereas weight or height at a given age are the results of the cumulative growth experience, growth velocities allows the study of factors affecting growth at given ages.

AIM

To study the relationships between parental height and body mass index (BMI) and offspring's height and weight growth during infancy and childhood.

STUDY DESIGN

From the FLVSII population-based study, 235 parent-child trios belonging to 162 families examined in 1999.

OUTCOME MEASURES

From medical records and previous FLVS examinations, child's height and weight history were reconstructed. Weight and height growth velocities from birth to seven years were estimated from a modelling of individual growth curve and correlated with parent's body size in 1999.

RESULTS

Ponderal index and length at birth were significantly associated with maternal but not paternal BMI and height. In the first six months, height growth velocity was significantly associated with maternal stature (at three months: 0.12+/-0.05 and 0.02+/-0.05 cm/month for a 10 cm difference in maternal and paternal height respectively) and weight growth velocity with paternal BMI (at three months: 5.7+/-2.8 and 1.9+/-2.3g/month for a difference of 1 kg/m(2) in paternal and maternal BMI respectively). Between two and five years, height growth velocity was more significantly associated with paternal height whereas weight growth velocity was more closely associated with maternal BMI.

CONCLUSIONS

Early childhood growth is characterised by alternate periods associated specifically with maternal or paternal BMI and height. This novel finding should trigger the search for specific genetic, epigenetic or environmentally shared factors from the mothers and fathers.

Latent variables and structural equation models for longitudinal relationships: an illustration in nutritional epidemiology

BACKGROUND

The use of structural equation modeling and latent variables remains uncommon in epidemiology despite its potential usefulness. The latter was illustrated by studying cross-sectional and longitudinal relationships between eating behavior and adiposity, using four different indicators of fat mass.

METHODS

Using data from a longitudinal community-based study, we fitted structural equation models including two latent variables (respectively baseline adiposity and adiposity change after 2 years of follow-up), each being defined, by the four following anthropometric measurement (respectively by their changes): body mass index, waist circumference, skinfold thickness and percent body fat. Latent adiposity variables were hypothesized to depend on a cognitive restraint score, calculated from answers to an eating-behavior questionnaire (TFEQ-18), either cross-sectionally or longitudinally.

RESULTS

We found that high baseline adiposity was associated with a 2-year increase of the cognitive restraint score and no convincing relationship between baseline cognitive restraint and 2-year adiposity change could be established.

CONCLUSIONS

The latent variable modeling approach enabled presentation of synthetic results rather than separate regression models and detailed analysis of the causal effects of interest. In the general population, restrained eating appears to be an adaptive response of subjects prone to gaining weight more than as a risk factor for fat-mass increase.

Obesity and cholesterol in Japanese, French, and U.S. children

The number of children at risk for overweight/obesity has increased dramatically in the last decade worldwide. This study compares measures of obesity (body mass index [BMI] and body fat percentage) and total cholesterol in 4,013 fourth-grade students from three countries, France, Japan, and the United States. Data were analyzed using t test, chi-square, and analysis of variance to determine differences between groups and by multiple linear regression. All variables differed significantly by group. BMI was highest in U.S. children. Body fat percentage was also highest in U.S. children and lowest in French children. Total cholesterol was highest in French children and lowest in U.S. White children. There were modest but significant associations between BMI and cholesterol in all groups except French children; associations varied by gender. Results indicate there was great variation in measures of obesity and cholesterol by country. The association between obesity and cholesterol may vary by culture, ethnicity, and gender.

Cognitive restraint, uncontrolled eating and emotional eating: correlations between parent and adolescent

The purpose of this study was to examine, in a general population, the resemblance in eating behaviour between adolescents and their parents. This study was based on the first examination of a community-based epidemiological study in Northern France. Subjects were offspring aged 14-22 years (135 boys and 125 girls) and their parents (174 fathers and 205 mothers). The Three-Factor Eating Questionnaire Revised 18-item version (TFEQ-R18) identified three aspects of eating behaviour: cognitive restraint of eating, uncontrolled eating and emotional eating. Familial resemblance in eating behaviour was measured by partial Spearman's correlations, adjusted for age and body mass index. Sons' uncontrolled eating was positively related to fathers' cognitive restraint of eating (r = 0.36), but not to fathers' uncontrolled eating (r = 0.07), nor to mothers' eating behaviour. Sons' cognitive restraint of eating was related to no parental eating behaviour scores. In daughters, cognitive restraint of eating was positively related to mothers' uncontrolled eating (r = 0.26), but not to mothers' cognitive restraint of eating (r = 0.13). Daughters' uncontrolled eating and emotional eating were positively associated with the same scores in mothers. Finally, daughters' eating behaviour was not related to fathers' eating behaviour. In conclusion, correlations in eating behaviour were higher with the parent of the same gender, and eating behaviours in adolescents seem to reflect opposition to parents' behaviour more than familial resemblance.

Child and parent characteristics related to parental feeding practices. A cross-cultural examination in the US and France

Although cross-cultural research between France and the United States has contributed to our understanding of adult eating habits, no research to date has considered differences in the way that French and American parents feed their children. American mothers (n=59) and fathers (n=38) and French mothers (n=72) and fathers (n=50) provided information about the feeding practices that they use with their children. U.S. parents reported higher levels of non-nutritive feeding practices and child control over feeding, whereas French parents reported greater monitoring and restriction of their child's food intake for weight reasons. Feeding practices were linked to child Body Mass Index (BMI) in both socio-cultural contexts.

Cyclic relationships between diabetic nephropathy and cardiovascular risk factors

The most common cause of death in diabetes is cardiovascular. Diabetic nephropathy has an important role in cardiovascular disease among susceptible diabetic patients. What is not well appreciated is that independent cardiovascular death risk factors (e.g., hypertension, hyperglycemia, dyslipidemias and microalbuminuria) may each have a cyclic relationship with diabetic nephropathy. Thus, as discussed in this review, each risk factor may aggravate diabetic nephropathy, increasing the likelihood of end-stage renal disease. Diabetic nephropathy in turn may aggravate each of the risk factors, increasing the likelihood of a cardiovascular event. These cardiovascular risk factors, amplified by vicious cycles with diabetic nephropathy, may then lead to accelerated cardiovascular morbidity and mortality.

Relationship between gamma-glutamyltransferase and fat mass in a general population of 8–17 years old children. The FLVS II study

AIM

Elevated gamma-glutamyltransferase (GGT) is positively associated with severity of obesity in obese children and with increased BMI and waist circumference in general populations of adults. We aimed to study the relationships between GGT and anthropometric parameters in a general population of children.

METHODS

This cross-sectional study was conducted in 219 boys and 214 girls included in the Fleurbaix Laventie Ville Santé II study. Weight, height, four skinfolds and waist circumference were measured. We compared the means of GGT activity according to gender and Tanner stage, and according to overweight status (IOTF definition) and quartiles of anthropometric parameters. We then calculated partial Pearson correlations by gender between GGT and anthropometric parameters taking age and Tanner stage into account.

RESULTS

GGT activity was higher in boys than in girls as soon as puberty started (P<0.001). The higher difference was observed for Tanner stage III (GGT=10.2 UI/L, CI95% of mean (9.5, 11.1) vs. 7.8 UI/L (7.2, 8.4)). Anthropometric parameters were significantly associated with GGT, particularly waist circumference (r=0.28 in boys; r=0.24 in girls). After an additional adjustment for sum of skinfolds, this correlation disappeared in boys (r=0.06), and was still significant in girls (r=0.19).

CONCLUSION

In a general population of children, overweight and abdominal fat distribution were associated with increased GGT. As some studies have shown that GGT could predict the metabolic syndrome in children and type 2 diabetes in adults, the modest elevation of GGT observed in overweight children may be of pathophysiological importance in the long term.

Gamma-glutamyltransferase activity and development of the metabolic syndrome (International Diabetes Federation Definition) in middle-aged men and women: Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort

OBJECTIVE

Among hepatic enzymes, gamma-glutamyltransferase (GGT) is the main predictor of type 2 diabetes incidence, although it has not been shown that GGT predicts pre-diabetes states. Our aim was to study the association of GGT with the development of the metabolic syndrome (MetS).

RESEARCH DESIGN AND METHODS

We analyzed the 3-year data from the Data from Epidemiological Study on the Insulin Resistance Syndrome prospective cohort of 1,656 men and 1,889 women without MetS at baseline, according to the International Diabetes Federation definition.

RESULTS

Over 3 years, 309 participants developed the MetS. After adjustment for age, alcohol intake, physical activity, smoking habits, and alanine aminotransferase (ALT), the odds ratios for incident MetS increased across baseline GGT quartiles (1, 1.96, 2.25, and 3.81 in men, P < 0.03; and 1, 1.23, 1.80, and 1.58 in women, P < 0.05). After additional adjustment for insulin resistance markers (fasting insulin or homeostasis model assessment of insulin resistance index), the association was attenuated and the linear relation no longer significant in both sexes (P = 0.08, P = 0.16). However, men in the highest in comparison to the lowest quartile of GGT retained a significant risk for incident MetS. In women, there was no longer a significant risk. GGT was significantly associated with the 3-year incidence of individual components of the MetS. The incidence of the MetS also increased with ALT, but after adjustment on GGT this association remained significant only in women.

CONCLUSIONS

GGT, a predictor of type 2 diabetes, was associated with a risk of incident MetS. This association was mainly related with insulin resistance but was independent of other confounding factors.

Calcium consumption and insulin resistance syndrome parameters. Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

BACKGROUND AND AIM

A number of studies have investigated the role of dietary calcium in lipid metabolism and weight regulation, and the influence of dairy products on the incidence of insulin resistance syndrome. In this study we have examined the relationship between dietary calcium and the established parameters of the insulin resistance syndrome.

METHODS AND RESULTS

The study population (n=4372) was taken from the DESIR (Data from the Epidemiological Study on the Insulin Resistance Syndrome) cohort. Data for parameters relating to the syndrome were recorded, including glucose, serum insulin, triglycerides, HDL-cholesterol, waist circumference and blood pressure. Total energy, calcium and alcohol intake were estimated using a food-frequency questionnaire. Relationships between dietary calcium density and the above parameters were analyzed by multiple linear regression models, adjusted for age, smoking, alcohol consumption and physical activity. From one quartile of calcium density to the next, mean systolic and diastolic blood pressures and insulin concentrations decreased in women by 0.9 mm Hg, 0.5 mm Hg and 2.4%, respectively, and HDL-cholesterol increased by 0.007 mmol/l (all p<0.05) after adjustment for age, smoking, alcohol intake and physical activity. In men, there was an increase of 0.2 kg/m(2) in the body mass index(BMI) and a decrease of 0.4 mm Hg in diastolic blood pressure (both p<0.05).

CONCLUSIONS

These results confirm a beneficial association between dietary calcium and arterial blood pressure, insulin and HDL-cholesterol levels in women, whereas in men there was only a beneficial association with diastolic blood pressure.

Comment on "A common genetic variant is associated with adult and childhood obesity"

Herbert et al. (Reports, 14 April 2006, p. 279) reported an association between the INSIG2 gene variant rs7566605 and obesity in four sample populations, under a recessive model. We attempted to replicate this result in 10,265 Caucasian individuals, combining family-based, case-control, and general population studies, but found no support for a major role of this variant in obesity.

No contribution of angiotensin-converting enzyme (ACE) gene variants to severe obesity: a model for comprehensive case/control and quantitative cladistic analysis of ACE in human diseases

Candidate gene analyses are often inconclusive owing to genetic or phenotypic heterogeneity, low statistical power, selection of nonfunctional SNPs, and inadequate statistical analysis of the genetic architecture. Angiotensin-converting enzyme (ACE) is involved in adipocyte growth and function and the ACE-processed angiotensin II inhibits adipocyte differentiation. Associations between body mass index (BMI) and ACE polymorphisms have been reported in general populations, but the contribution to severe obesity of this gene, which is located under an obesity genome-scan linkage peak on 17q23, is unknown. ACE is one of the most studied genes and markers responsible for variation in circulating ACE enzyme levels have been extensively characterised. Eight of these variants were genotyped in 1054 severely obese cases and 918 nonobese controls, as well as 116 nuclear families from the genome scan (n=447), enabling the known clades to be inferred. Qualitative analysis of individual single-nucleotide polymorphisms (SNPs), haplotypes, clades, and diploclades demonstrated no significant associations (P<0.05) after minimal correction for multiple testing. Quantitative analysis of clades and diploclades for BMI, waist-to-hip ratio, or ZBMI in children were also not significant. This rigorous, large-scale study of common, well-defined, severe polygenic obesity provides strong evidence that functionally relevant sequence variation in ACE, whether it is defined at the level of SNPs, haplotypes, or clades, is not associated with severe obesity in French Caucasians. Such a study design exemplifies the strategy needed to clearly define the contribution of the ACE gene to the plethora of complex genetic diseases where weak associations have been previously reported.