Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia…

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions…

OP VI – 5 Spatial and temporal variability of personal exposure to radio frequency electromagnetic fields in children in europe

Background/aim Exposure to radiofrequency electromagnetic fields (RF-EMF) has rapidly increased and little is known about exposure levels in children. This study aims to describe personal RF-EMF environmental exposure levels from handheld devices and fixed site transmitters in European children and its day-to-day and year-to-year repeatability. Methods Environmental RF-EMF exposure (µW/m 2 ) was measured in 529 children (ages 8–18) in Denmark, the Netherlands, Slovenia, Switzerland, and Spain using personal portable exposure metres over 3 days in 2014–2016, and repeated in 28 children one year later. Metres captured exposure every 4 s. Activity diaries collected children’s location and use …

Author response: Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

Air Pollution Exposure During Pregnancy and Symptoms of Attention Deficit and Hyperactivity Disorder in Children in Europe

Background: Exposure to air pollution during pregnancy may increase attention-deficit/hyperactivity disorder (ADHD) symptoms in children, but findings have been inconsistent. We aimed to study this association in a collaborative study of eight European population-based birth/child cohorts, including 29,127 mother-child pairs. Methods: Air pollution concentrations (nitrogen dioxide [NO2] and particulate matter [PM]) were estimated at the birth address by land-use regression models based on monitoring campaigns performed between 2008 and 2011. We extrapolated concentrations back in time to exact pregnancy periods. Teachers or parents assessed ADHD symptoms at 3-10 years of age. We classified …

Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis

BACKGROUND: Women of reproductive age can be exposed to endocrine-disrupting chemicals (EDCs) at work, and exposure to EDCs in pregnancy may affect fetal growth. OBJECTIVES: We assessed whether maternal occupational exposure to EDCs during pregnancy as classified by application of a job exposure matrix was associated with birth weight, term low birth weight (LBW), length of gestation, and preterm delivery. METHODS: Using individual participant data from 133,957 mother-child pairs in 13 European cohorts spanning births from 1994 through 2011, we linked maternal job titles with exposure to 10 EDC groups as assessed through a job exposure matrix. For each group, we combined the two levels of e…

Does early onset asthma increase childhood obesity risk? A pooled analysis of 16 European cohorts

The parallel epidemics of childhood asthma and obesity over the past few decades have spurred research into obesity as a risk factor for asthma. However, little is known regarding the role of asthma in obesity incidence. We examined whether early-onset asthma and related phenotypes are associated with the risk of developing obesity in childhood.This study includes 21 130 children born from 1990 to 2008 in Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden and the UK. We followed non-obese children at 3-4 years of age for incident obesity up to 8 years of age. Physician-diagnosed asthma, wheezing and allergic rhinitis were assessed up to 3-4 years of age.Children with ph…

Novel loci for childhood body mass index and shared heritability with adult cardiometabolic traits

The genetic background of childhood body mass index (BMI), and the extent to which the well-known associations of childhood BMI with adult diseases are explained by shared genetic factors, are largely unknown. We performed a genome-wide association study meta-analysis of BMI in 61,111 children aged between 2 and 10 years. Twenty-five independent loci reached genome-wide significance in the combined discovery and replication analyses. Two of these, located nearNEDD4LandSLC45A3, have not previously been reported in relation to either childhood or adult BMI. Positive genetic correlations of childhood BMI with birth weight and adult BMI, waist-to-hip ratio, diastolic blood pressure and type 2 d…

Impact of Low Maternal Education on Early Childhood Overweight and Obesity in Europe

BackgroundComparable evidence on adiposity inequalities in early life is lacking across a range of European countries. This study investigates whether low maternal education is associated with overweight and obesity risk in children from distinct European settings during early childhood. MethodsProspective data of 45 413 children from 11 European cohorts were used. Children's height and weight obtained at ages 4-7 years were used to assess prevalent overweight and obesity according to the International Obesity Task Force definition. The Relative/Slope Indices of Inequality (RII/SII) were estimated within each cohort and by gender to investigate adiposity risk among children born to mothers …

Maternal and fetal genetic effects on birth weight and their relevance to cardio-metabolic risk factors

AbstractBirth weight (BW) variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. These associations have been proposed to reflect the lifelong consequences of an adverse intrauterine environment. In earlier work, we demonstrated that much of the negative correlation between BW and adult cardio-metabolic traits could instead be attributable to shared genetic effects. However, that work and other previous studies did not systematically distinguish the direct effects of an individual’s own genotype on BW and subsequent disease risk from indirect effects of their mother’s correlated genoty…

Associations of Maternal Cell-Phone Use During Pregnancy With Pregnancy Duration and Fetal Growth in 4 Birth Cohorts

Results from studies evaluating potential effects of prenatal exposure to radio-frequency electromagnetic fields from cell phones on birth outcomes have been inconsistent. Using data on 55,507 pregnant women and their children from Denmark (1996-2002), the Netherlands (2003-2004), Spain (2003-2008), and South Korea (2006-2011), we explored whether maternal cell-phone use was associated with pregnancy duration and fetal growth. On the basis of self-reported number of cell-phone calls per day, exposure was grouped as none, low (referent), intermediate, or high. We examined pregnancy duration (gestational age at birth, preterm/postterm birth), fetal growth (birth weight ratio, small/large size…

Additional file 1 of Ideal cardiovascular health at age 5–6 years and cardiometabolic outcomes in preadolescence

Additional file 1: Supplementary Table 1. Characteristics of included and non-included children. Supplementary Table 2. Defining Ideal Cardiovascular Health. Supplementary Table 3. Association between original ICH score and cardiovascular health outcomes at age 5-6 years. Supplementary Table 4. Association between original ICH score at age 5-6 years and cardiovascular health outcomes at age 11-12 years.

Association of Thyroid Function Test Abnormalities and Thyroid Autoimmunity With Preterm Birth A Systematic Review and Meta-analysis

Preterm birth complicates 5% to 15% of births worldwide, and although it is the most important direct cause of morbidity and mortality in children younger than 5 years, no known risk factors can be identified in the majority of cases. However, overt hypothyroidism and hyperthyroidism during pregnancy are well-known risk factors for preterm birth, and as such, the purpose of this study was to assess whether thyroid function test abnormalities and thyroid peroxidase (TPO) antibody positivity were associated with preterm birth. The study conducted a systematic review on the association of thyroid function or autoimmunity with preterm birth published from database inception to March 18, 2018, w…

Impact of maternal body mass index and gestational weight gain on pregnancy complications: an individual participant data meta-analysis of European, North American and Australian cohorts

ObjectiveTo assess the separate and combined associations of maternal pre‐pregnancy body mass index (BMI) and gestational weight gain with the risks of pregnancy complications and their population impact.DesignIndividual participant data meta‐analysis of 39 cohorts.SettingEurope, North America, and Oceania.Population265 270 births.MethodsInformation on maternal pre‐pregnancy BMI, gestational weight gain, and pregnancy complications was obtained. Multilevel binary logistic regression models were used.Main outcome measuresGestational hypertension, pre‐eclampsia, gestational diabetes, preterm birth, small and large for gestational age at birth.ResultsHigher maternal pre‐pregnancy BMI and gesta…

Fish and seafood consumption during pregnancy and the risk of asthma and allergic rhinitis in childhood

Background: It has been suggested that prenatal exposure to n-3 long-chain fatty acids protects against asthma and other allergy-related diseases later in childhood. The extent to which fish intake in pregnancy protects against child asthma and rhinitis symptoms remains unclear. We aimed to assess whether fish and seafood consumption in pregnancy is associated with childhood wheeze, asthma and allergic rhinitis. Methods: We pooled individual data from 60 774 mother-child pairs participating in 18 European and US birth cohort studies. Information on wheeze, asthma and allergic rhinitis prevalence was collected using validated questionnaires. The time periods of interest were: infancy (0-2 ye…

Changes in parental smoking during pregnancy and risks of adverse birth outcomes and childhood overweight in Europe and North America

Background Fetal smoke exposure is a common and key avoidable risk factor for birth complications and seems to influence later risk of overweight. It is unclear whether this increased risk is also present if mothers smoke during the first trimester only or reduce the number of cigarettes during pregnancy, or when only fathers smoke. We aimed to assess the associations of parental smoking during pregnancy, specifically of quitting or reducing smoking and maternal and paternal smoking combined, with preterm birth, small size for gestational age, and childhood overweight. Methods and findings We performed an individual participant data meta-analysis among 229,158 families from 28 pregnancy/bir…

Association of Exposure to Ambient Air Pollution With Thyroid Function During Pregnancy

Key Points Question Is exposure to ambient air pollution in the first trimester associated with thyroid function throughout pregnancy? Findings Among 9931 pregnant women in 4 European cohorts and 1 US cohort, an increase of 5 μg/m3 in exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less was associated with 20% higher odds of hypothyroxinemia. Meaning The findings of this study raise the possibility that exposure to particulate matter might disrupt thyroid function in pregnant women.

Maternal body mass index, gestational weight gain, and the risk of overweight and obesity across childhood: An individual participant data meta-analysis

Background Maternal obesity and excessive gestational weight gain may have persistent effects on offspring fat development. However, it remains unclear whether these effects differ by severity of obesity, and whether these effects are restricted to the extremes of maternal body mass index (BMI) and gestational weight gain. We aimed to assess the separate and combined associations of maternal BMI and gestational weight gain with the risk of overweight/obesity throughout childhood, and their population impact. Methods and findings We conducted an individual participant data meta-analysis of data from 162,129 mothers and their children from 37 pregnancy and birth cohort studies from Europe, No…

Fish Intake in Pregnancy and Child Growth: A Pooled Analysis of 15 European and US Birth Cohorts

Importance Maternal fish intake in pregnancy has been shown to influence fetal growth. The extent to which fish intake affects childhood growth and obesity remains unclear. Objective To examine whether fish intake in pregnancy is associated with offspring growth and the risk of childhood overweight and obesity. Design, Setting, and Participants Multicenter, population-based birth cohort study of singleton deliveries from 1996 to 2011 in Belgium, France, Greece, Ireland, Italy, the Netherlands, Norway, Poland, Portugal, Spain, and Massachusetts. A total of 26 184 pregnant women and their children were followed up at 2-year intervals until the age of 6 years. Exposures Consumption of fish dur…