Exposure to non-persistent pesticides and sexual maturation of Spanish adolescent males.

BACKGROUND: Several non-persistent pesticides are endocrine disrupting chemicals and may impact on sexual maturation. OBJECTIVE: To examine the association between urinary biomarkers of non-persistent pesticides and sexual maturation in adolescent males in the Environment and Childhood (INMA) Project. METHODS: The metabolites of several pesticides were measured in spot urine samples collected from 201 boys aged 14-17 years, including: 3,5,6-trichloro-2-pyridinol (TCPy), metabolite of chlorpyrifos; 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPy), metabolite of diazinon; malathion diacid (MDA), metabolite of malathion; diethyl thiophosphate (DETP) and diethyl dithiophosphate, non-specific metabolites of organophosphates; 3-phenoxybenzoic acid (3-PBA) and dimethyl cyclopropane carboxylic acid, metabolites of pyrethroids; 1-naphthol (1-NPL), metabolite of carbaryl; and ethylene thiourea (ETU), metabolite of dithiocarbamate fungicides. Sexual maturation was assessed using Tanner stages, self-reported Pubertal Development Scale, and testicular volume (TV). Multivariate logistic regression was employed to examine associations between urinary pesticide metabolites and the odds of being in Tanner stage 5 of genital development (G5) or pubic hair growth (PH5); stage ≥4 of overall pubertal development, gonadarche, and adrenarche; or having mature TV (≥25 mL). RESULTS: DETP concentrations>75th percentile (P75) were associated with lower odds of being in stage G5 (OR = 0.27; 95% CI = 0.10-0.70), detectable TCPy with lower odds of gonadal stage≥4 (OR = 0.50; 95% CI = 0.26-0.96), and intermediate detectable MDA concentrations (

Spirometric phenotypes from early childhood to young adulthood: a Chronic Airway Disease Early Stratification study.

BACKGROUND: The prevalences of obstructive and restrictive spirometric phenotypes, and their relation to early-life risk factors from childhood to young adulthood remain poorly understood. The aim was to explore these phenotypes and associations with well-known respiratory risk factors across ages and populations in European cohorts. METHODS: We studied 49 334 participants from 14 population-based cohorts in different age groups (≤10, >10-15, >15-20, >20-25 years, and overall, 5-25 years). The obstructive phenotype was defined as forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) z-score less than the lower limit of normal (LLN), whereas the restrictive phenotype was defined as FEV1/FVC z-score ≥LLN, and FVC z-score

Radiofrequency electromagnetic fields from mobile communication: Description of modeled dose in brain regions and the body in European children and adolescents.

BACKGROUND: Little is known about radiofrequency electromagnetic fields (RF) from mobile technology and resulting dose in young people. We describe modeled integrated RF dose in European children and adolescents combining own mobile device use and surrounding sources. METHODS: Using an integrated RF model, we estimated the daily RF dose in the brain (whole-brain, cerebellum, frontal lobe, midbrain, occipital lobe, parietal lobe, temporal lobes) and the whole-body in 8358 children (ages 8-12) and adolescents (ages 14-18) from the Netherlands, Spain, and Switzerland during 2012-2016. The integrated model estimated RF dose from near-field sources (digital enhanced communication technology (DECT) phone, mobile phone, tablet, and laptop) and far-field sources (mobile phone base stations via 3D-radiowave modeling or RF measurements). RESULTS: Adolescents were more frequent mobile phone users and experienced higher modeled RF doses in the whole-brain (median 330.4 mJ/kg/day) compared to children (median 81.8 mJ/kg/day). Children spent more time using tablets or laptops compared to adolescents, resulting in higher RF doses in the whole-body (median whole-body dose of 81.8 mJ/kg/day) compared to adolescents (41.9 mJ/kg/day). Among brain regions, temporal lobes received the highest RF dose (medians of 274.9 and 1786.5 mJ/kg/day in children and adolescents, respectively) followed by the frontal lobe. In most children and adolescents, calling on 2G networks was the main contributor to RF dose in the whole-brain (medians of 31.1 and 273.7 mJ/kg/day, respectively). CONCLUSION: This first large study of RF dose to the brain and body of children and adolescents shows that mobile phone calls on 2G networks are the main determinants of brain dose, especially in temporal and frontal lobes, whereas whole-body doses were mostly determined by tablet and laptop use. The modeling of RF doses provides valuable input to epidemiological research and to potential risk management regarding RF exposure in young people.

Association between estimated whole-brain radiofrequency electromagnetic fields dose and cognitive function in preadolescents and adolescents.

OBJECTIVE: To investigate the association between estimated whole-brain radiofrequency electromagnetic fields (RF-EMF) dose, using an improved integrated RF-EMF exposure model, and cognitive function in preadolescents and adolescents. METHODS: Cross-sectional analysis in preadolescents aged 9-11 years and adolescents aged 17-18 years from the Dutch Amsterdam Born Children and their Development Study (n = 1664 preadolescents) and the Spanish INfancia y Medio Ambiente Project (n = 1288 preadolescents and n = 261 adolescents), two population-based birth cohort studies. Overall whole-brain RF-EMF doses (mJ/kg/day) were estimated for several RF-EMF sources together including mobile and Digital Enhanced Cordless Telecommunications phone calls (named phone calls), other mobile phone uses than calling, tablet use, laptop use (named screen activities), and far-field sources. We also estimated whole-brain RF-EMF doses in these three groups separately (i.e. phone calls, screen activities, and far-field) that lead to different patterns of RF-EMF exposure. We assessed non-verbal intelligence in the Dutch and Spanish preadolescents, information processing speed, attentional function, and cognitive flexibility in the Spanish preadolescents, and working memory and semantic fluency in the Spanish preadolescents and adolescents using validated neurocognitive tests. RESULTS: Estimated overall whole-brain RF-EMF dose was 90.1 mJ/kg/day (interquartile range (IQR) 42.7; 164.0) in the Dutch and Spanish preadolescents and 105.1 mJ/kg/day (IQR 51.0; 295.7) in the Spanish adolescents. Higher overall estimated whole-brain RF-EMF doses from all RF-EMF sources together and from phone calls were associated with lower non-verbal intelligence score in the Dutch and Spanish preadolescents (-0.10 points, 95% CI -0.19; -0.02 per 100 mJ/kg/day increase in each exposure). However, none of the whole-brain RF-EMF doses was related to any other cognitive function outcome in the Spanish preadolescents or adolescents. CONCLUSIONS: Our results suggest that higher brain exposure to RF-EMF is related to lower non-verbal intelligence but not to other cognitive function outcomes. Given the cross-sectional nature of the study, the small effect sizes, and the unknown biological mechanisms, we cannot discard that our resultsare due to chance finding or reverse causality. Longitudinal studies on RF-EMF brain exposure and cognitive function are needed.

Personal exposure to radio-frequency electromagnetic fields in Europe: Is there a generation gap?

BACKGROUND: Exposure to radiofrequency electromagnetic fields (RF-EMF) from mobile communication technologies is changing rapidly. To characterize sources and associated variability, we studied the differences and correlations in exposure patterns between children aged 8 to 18 and their parents, over the course of the day, by age, by activity pattern, and for different metrics of exposure. METHODS: Using portable RF-EMF measurement devices, we collected simultaneous real-time personal measurements of RF-EMF over 24 to 72 h in 294 parent-child pairs from Denmark, the Netherlands, Slovenia, Switzerland, and Spain. The devices measured the power flux density (mW/m2) in 16 different frequency bands every 4 s, and activity diary Apps kept by the participants were used to collect time-activity information in real-time. We analyzed their exposures by activity, for the different source constituents of exposure: downlink (radiation emitted from mobile phone base stations), uplink (transmission from phone to base station), broadcast, DECT (digital enhanced cordless telecommunications) and Wi-Fi. We looked at the correlations between parents and children overall, during day (06:00-22.00) and night (22:00-06:00) and while spending time at home. RESULTS: The mean of time-weighted average personal exposures was 0.16 mW/m2 for children and 0.15 mW/m2 for parents, on average predominantly originating from downlink sources (47% for children and 45% for parents), followed by uplink (18% and 27% respectively) and broadcast (25% and 19%). On average, exposure for downlink and uplink were highest during the day, and for Wi-Fi and DECT during the evening. Exposure during activities where most of the time is spent (home, school and work) was relatively low whereas exposure during travel and outside activities was higher. Exposure to uplink increased with age among young people, while DECT decreased slightly. Exposure to downlink, broadcast, and Wi-Fi showed no obvious trend with age. We found that exposure to total RF-EMF is correlated among children and their parents (Rspearman = 0.45), especially while at home (0.62) and during the night (0.60). Correlations were higher for environmental sources such as downlink (0.57) and broadcast (0.62) than for usage-related exposures such as uplink (0.29). CONCLUSION: The generation gap between children and their parents is mostly evident in uplink exposure, due to more and longer uplink and cordless phone calls among parents, and their tendency to spend slightly more time in activities with higher environmental RF-EMF exposure, such as travel. Despite these differences in personal behavior, exposure to RF-EMF is moderately correlated between children and their parents, especially exposures resulting from environmental RF-EMF sources.

Spatial and temporal variability of personal environmental exposure to radio frequency electromagnetic fields in children in Europe.

BACKGROUND: Exposure to radiofrequency electromagnetic fields (RF-EMF) has rapidly increased and little is known about exposure levels in children. This study describes personal RF-EMF environmental exposure levels from handheld devices and fixed site transmitters in European children, the determinants of this, and the day-to-day and year-to-year repeatability of these exposure levels. METHODS: Personal environmental RF-EMF exposure (µW/m2, power flux density) was measured in 529 children (ages 8-18 years) in Denmark, the Netherlands, Slovenia, Switzerland, and Spain using personal portable exposure meters for a period of up to three days between 2014 and 2016, and repeated in a subsample of 28 children one year later. The meters captured 16 frequency bands every 4 s and incorporated a GPS. Activity diaries and questionnaires were used to collect children's location, use of handheld devices, and presence of indoor RF-EMF sources. Six general frequency bands were defined: total, digital enhanced cordless telecommunications (DECT), television and radio antennas (broadcast), mobile phones (uplink), mobile phone base stations (downlink), and Wireless Fidelity (WiFi). We used adjusted mixed effects models with region random effects to estimate associations of handheld device use habits and indoor RF-EMF sources with personal RF-EMF exposure. Day-to-day and year-to-year repeatability of personal RF-EMF exposure were calculated through intraclass correlations (ICC). RESULTS: Median total personal RF-EMF exposure was 75.5 µW/m2. Downlink was the largest contributor to total exposure (median: 27.2 µW/m2) followed by broadcast (9.9 µW/m2). Exposure from uplink (4.7 µW/m2) was lower. WiFi and DECT contributed very little to exposure levels. Exposure was higher during day (94.2 µW/m2) than night (23.0 µW/m2), and slightly higher during weekends than weekdays, although varying across regions. Median exposures were highest while children were outside (157.0 µW/m2) or traveling (171.3 µW/m2), and much lower at home (33.0 µW/m2) or in school (35.1 µW/m2). Children living in urban environments had higher exposure than children in rural environments. Older children and users of mobile phones had higher uplink exposure but not total exposure, compared to younger children and those that did not use mobile phones. Day-to-day repeatability was moderate to high for most of the general frequency bands (ICCs between 0.43 and 0.85), as well as for total, broadcast, and downlink for the year-to-year repeatability (ICCs between 0.49 and 0.80) in a small subsample. CONCLUSION: The largest contributors to total personal environmental RF-EMF exposure were downlink and broadcast, and these exposures showed high repeatability. Urbanicity was the most important determinant of total exposure and mobile phone use was the most important determinant of uplink exposure. It is important to continue evaluating RF-EMF exposure in children as device use habits, exposure levels, and main contributing sources may change.

Prenatal exposure to endocrine disrupting chemicals and risk of being born small for gestational age: Pooled analysis of seven European birth cohorts.

BACKGROUND AND AIMS: There is evidence that endocrine disrupting chemicals (EDCs) have developmental effects at environmental concentrations. We investigated whether some EDCs are associated with the adverse birth outcome Small for Gestational Age (SGA). METHODS: We used PCB 153, p,p'-DDE, HCB, PFOS and PFOA measured in maternal, cord blood or breast milk samples of 5446 mother-child pairs (subset of 693 for the perfluorinated compounds) from seven European birth cohorts (1997-2012). SGA infants were those with birth weight below the 10th percentile for the norms defined by gestational age, country and infant's sex. We modelled the association between measured or estimated cord serum EDC concentrations and SGA using multiple logistic regression analyses. We explored effect modification by child's sex and maternal smoking during pregnancy. RESULTS: Among the 5446 newborns, 570 (10.5%) were SGA. An interquartile range (IQR) increase in PCB 153 was associated with a modestly increased risk of SGA (odds ratio (OR) of 1.05 [95% CI: 1.04-1.07]) that was stronger in girls (OR of 1.09 [95% CI: 1.04-1.14]) than in boys (OR of 1.03 [95% CI: 1.03-1.04]) (p-interaction = 0.025). For HCB, we found a modestly increased odds of SGA in girls (OR of 1.04 [95% CI: 1.01-1.07] per IQR increase), and an inverse association in boys (OR of 0.90 [95% CI: 0.85-0.95]) (p-interaction = 0.0003). Assessment of the HCB-sex-smoking interaction suggested that the increased odds of SGA associated with HCB exposure was only in girls of smoking mothers (OR of 1.18 [95% CI: 1.11-1.25]) (p-interaction = 0.055). Higher concentrations of PFOA were associated with greater risk of SGA (OR of 1.64 [95% CI: 0.97-2.76]). Elevated PFOS levels were associated with increased odds of SGA in newborns of mothers who smoked during pregnancy (OR of 1.63 [95% CI: 1.02-2.59]), while an inverse association was found in those of non-smoking mothers (OR of 0.66 [95% CI: 0.61-0.72]) (p-interaction = 0.0004). No significant associations were found for p,p'-DDE. CONCLUSIONS: Prenatal environmental exposure to organochlorine and perfluorinated compounds with endocrine disrupting properties may contribute to the prevalence of SGA. We found indication of effect modification by child's sex and smoking during pregnancy. The direction of the associations differed by chemical and these effect modifiers, suggesting diverse mechanisms of action and biological pathways.

Mother's education and offspring asthma risk in 10 European cohort studies.

Highly prevalent and typically beginning in childhood, asthma is a burdensome disease, yet the risk factors for this condition are not clarified. To enhance understanding, this study assessed the cohort-specific and pooled risk of maternal education on asthma in children aged 3-8 across 10 European countries. Data on 47,099 children were obtained from prospective birth cohort studies across 10 European countries. We calculated cohort-specific prevalence difference in asthma outcomes using the relative index of inequality (RII) and slope index of inequality (SII). Results from all countries were pooled using random-effects meta-analysis procedures to obtain mean RII and SII scores at the European level. Final models were adjusted for child sex, smoking during pregnancy, parity, mother's age and ethnicity. The higher the score the greater the magnitude of relative (RII, reference 1) and absolute (SII, reference 0) inequity. The pooled RII estimate for asthma risk across all cohorts was 1.46 (95% CI 1.26, 1.71) and the pooled SII estimate was 1.90 (95% CI 0.26, 3.54). Of the countries examined, France, the United Kingdom and the Netherlands had the highest prevalence's of childhood asthma and the largest inequity in asthma risk. Smaller inverse associations were noted for all other countries except Italy, which presented contradictory scores, but with small effect sizes. Tests for heterogeneity yielded significant results for SII scores. Overall, offspring of mothers with a low level of education had an increased relative and absolute risk of asthma compared to offspring of high-educated mothers.

The association between passive and active tobacco smoke exposure and child weight status among Spanish children.

OBJECTIVE: To assess the impact of passive and active tobacco smoke exposure, both pre- and postnatally, on child body mass index (BMI) and overweight. METHODS: Pregnant women were enrolled into the Spanish INMA prospective birth cohort during 1997 to 2008. Tobacco smoke exposure was assessed by questionnaire and corroborated by pre- and postnatal cotinine measurements. Children were followed up until 4 years in newer subcohorts (N = 1866) and until 14 years in one older subcohort (N = 427). Child age- and sex-specific BMI Z-scores were calculated, and generalized estimating equations were used to model their relationship with repeated measures of tobacco smoke exposure. RESULTS: Associations between prenatal passive exposure to tobacco smoke (adjusted ß = 0.15, 95% CI: 0.05-0.25) and active maternal smoking (adjusted ß = 0.20, 95% CI: 0.08-0.33) and child zBMI up to 4 years were observed. Stronger associations were observed in the older subcohort between both prenatal and child passive smoke exposure and zBMI up to 14 years. CONCLUSIONS: Evidence for an effect of both passive and maternal active smoking on child postnatal growth has been provided. Although residual confounding cannot be completely ruled out, associations were robust to adjustment for a range of lifestyle factors.

Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol.

BACKGROUND: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood) Project, a prospective cohort study. METHODS/DESIGN: Indirect (proximity to emission sources, questionnaires on sources use and geospatial propagation models) and direct methods (spot and fixed longer-term measurements and personal measurements) were conducted in order to assess exposure levels of study participants aged between 7 and 18 years old. The methodology used varies depending on the frequency of the EMF-NIR and the environment (homes, schools and parks). Questionnaires assessed the use of sources contributing both to Extremely Low Frequency (ELF) and Radiofrequency (RF) exposure levels. Geospatial propagation models (NISMap) are implemented and validated for environmental outdoor sources of RFs using spot measurements. Spot and fixed longer-term ELF and RF measurements were done in the environments where children spend most of the time. Moreover, personal measurements were taken in order to assess individual exposure to RF. The exposure data are used to explore their relationships with proximity and/or use of EMF-NIR sources. DISCUSSION: Characterisation of the EMF-NIR exposure by this combination of methods is intended to overcome problems encountered in other research. The assessment of exposure of INMA cohort children and adolescents living in different regions of Spain to the full frequency range of EMF-NIR extends the characterisation of environmental exposures in this cohort. Together with other data obtained in the project, on socioeconomic and family characteristics and development of the children and adolescents, this will enable to evaluate the complex interaction between health outcomes in children and adolescents and the various environmental factors that surround them.

Prenatal exposure to PCB-153, p,p'-DDE and birth outcomes in 9000 mother-child pairs: exposure-response relationship and effect modifiers.

Low-level exposure to polychlorinated biphenyl-153 (PCB-153) and dichlorodiphenyldichloroethylene (p-p'-DDE) can impair fetal growth; however, the exposure-response relationship and effect modifiers of such association are not well established. This study is an extension of an earlier European meta-analysis. Our aim was to explore exposure-response relationship between PCB-153 and p-p'-DDE and birth outcomes; to evaluate whether any no exposure-effect level and susceptible subgroups exist; and to assess the role of maternal gestational weight gain (GWG). We used a pooled dataset of 9377 mother-child pairs enrolled in 14 study populations from 11 European birth cohorts. General additive models were used to evaluate the shape of the relationships between organochlorine compounds and birth outcomes. We observed an inverse linear exposure-response relationship between prenatal exposure to PCB-153 and birth weight [decline of 194g (95% CI -314, -74) per 1µg/L increase in PCB-153]. We showed effects on birth weight over the entire exposure range, including at low levels. This reduction seems to be stronger among children of mothers who were non-Caucasian or had smoked during pregnancy. The most susceptible subgroup was girls whose mothers smoked during pregnancy. After adjusting for absolute GWG or estimated fat mass, a reduction in birth weight was still observed. This study suggests that the association between low-level exposure to PCB-153 and birth weight exists and follows an inverse linear exposure-response relationship with effects even at low levels, and that maternal smoking and ethnicity modify this association.

Effectiveness of a complex intervention in reducing the prevalence of smoking among adolescents: study design of a cluster-randomized controlled trial.

BACKGROUND: The likelihood of an adolescent taking up smoking may be influenced by his or her society, school and family. Thus, changes in the immediate environment may alter a young person's perception of smoking. METHODS/DESIGN: The proposed multi-center, cluster-randomized controlled trial will be stratified by the baseline prevalence of smoking in schools. Municipalities with fewer than 100,000 inhabitants will be randomly assigned to a control or intervention group. One secondary school will be randomly selected from each municipality. These schools will be randomized to two groups: the students of one will receive any existing educational course regarding smoking, while those of the other school will receive a four-year, class-based curriculum intervention (22 classroom lessons) aimed at reinforcing a smoke-free school policy and encouraging smoking cessation in parents, pupils, and teachers. The intervention will also include annual meetings with parents and efforts to empower adolescents to change the smoking-related attitudes and behaviors in their homes, classrooms and communities.We will enroll children aged 12-13 years as they enter secondary school during two consecutive school years (to obtain sufficient enrolled subjects). We will follow them for five years, until two years after they leave secondary school. All external evaluators and analysts will be blinded to school allocation.The aim of this study is to analyze the effectiveness of a complex intervention in reducing the prevalence of smoking in the third year of compulsory secondary education (ESO) and two years after secondary school, when the participants are 14-15 and 17-18 years old, respectively. DISCUSSION: Most interventions aimed at preventing smoking among adolescents yield little to no positive long-term effects. This clinical trial will analyze the effectiveness of a complex intervention aimed at reducing the incidence and prevalence of smoking in this vulnerable age group. TRIAL REGISTRATION: Current Controlled Trials: NCT01602796.

Fraction of exhaled nitric oxide values in childhood are associated with 17q11.2-q12 and 17q12-q21 variants.

BACKGROUND: The fraction of exhaled nitric oxide (Feno) value is a biomarker of eosinophilic airway inflammation and is associated with childhood asthma. Identification of common genetic variants associated with childhood Feno values might help to define biological mechanisms related to specific asthma phenotypes. OBJECTIVE: We sought to identify the genetic variants associated with childhood Feno values and their relation with asthma. METHODS: Feno values were measured in children age 5 to 15 years. In 14 genome-wide association studies (N = 8,858), we examined the associations of approximately 2.5 million single nucleotide polymorphisms (SNPs) with Feno values. Subsequently, we assessed whether significant SNPs were expression quantitative trait loci in genome-wide expression data sets of lymphoblastoid cell lines (n = 1,830) and were related to asthma in a previously published genome-wide association data set (cases, n = 10,365; control subjects: n = 16,110). RESULTS: We identified 3 SNPs associated with Feno values: rs3751972 in LYR motif containing 9 (LYRM9; P = 1.97 × 10(-10)) and rs944722 in inducible nitric oxide synthase 2 (NOS2; P = 1.28 × 10(-9)), both of which are located at 17q11.2-q12, and rs8069176 near gasdermin B (GSDMB; P = 1.88 × 10(-8)) at 17q12-q21. We found a cis expression quantitative trait locus for the transcript soluble galactoside-binding lectin 9 (LGALS9) that is in linkage disequilibrium with rs944722. rs8069176 was associated with GSDMB and ORM1-like 3 (ORMDL3) expression. rs8069176 at 17q12-q21, but not rs3751972 and rs944722 at 17q11.2-q12, were associated with physician-diagnosed asthma. CONCLUSION: This study identified 3 variants associated with Feno values, explaining 0.95% of the variance. Identification of functional SNPs and haplotypes in these regions might provide novel insight into the regulation of Feno values. This study highlights that both shared and distinct genetic factors affect Feno values and childhood asthma.

Influence of socio-demographic and diet determinants on the levels of mercury in preschool children from a Mediterranean island.

Mercury levels measured in 302 hair samples of 4 year-old children from Menorca (western Mediterranean Sea) are reported. Their concentrations, arithmetic mean 1.4 µg/g, ranging between 0.040 µg/g and 10 µg/g, were higher than in other children inland populations but lower than in previously studied island cohorts, e.g. Faroe, Madeira and Seychelles. 20% of the samples were above the WHO recommended values. Higher concentrations in females than males were observed. Frequent consumption of fish and other seafood were significantly related to the observed mercury concentrations. Oily fish was the main source of this pollutant but shellfish and squid consumption were also associated with high mercury concentrations. Maternal smoking, occupational status or previous siblings were also found to significantly influence the levels of this pollutant. McCarthy Scales of Children's Abilities used to assess children's motor and cognitive abilities did not show association with mercury concentrations at 4 years of age.

School, family and adolescent smoking.

The socio-cultural environment is an important factor involved with the onset of smoking during adolescence. Initiation of cigarette smoking occurs almost exclusively during this stage. In this context we aimed to analyze the association of school and family factors with adolescent smoking by a cross-sectional study of 16 secondary schools randomly selected from the Balearic Islands involved 3673 students and 530 teachers. The prevalence of regular smoking (at least one cigarette per week) was 4.8% among first year students, 11.6% among second year students, 14.1% among third year students, 20.9% among fourth year students and 22% among teachers. Among first and second year students, there were independent associations between regular smoking and adolescents' perception of being allowed to smoke at home, belonging to a single parent family, poor relationship with parents, poor academic performance, lack of interest in studies and teachers' perception of smoking in the presence of pupils. Among third and fourth year students, there were independent associations between regular smoking and poor relationship with parents, adolescents' perception of being allowed to smoke at home, poor academic performance, lack of control over student misbehavior and the school attended. The school policies and practices affect student related health behavior regarding smoking, independent of individual and family factors.

Body mass index trajectory classes and incident asthma in childhood: results from 8 European Birth Cohorts--a Global Allergy and Asthma European Network initiative.

BACKGROUND: The causal link between body mass index (BMI) or obesity and asthma in children is still being debated. Analyses of large longitudinal studies with a sufficient number of incident cases and in which the time-dependent processes of both excess weight and asthma development can be validly analyzed are lacking. OBJECTIVE: We sought to investigate whether the course of BMI predicts incident asthma in childhood. METHODS: Data from 12,050 subjects of 8 European birth cohorts on asthma and allergies were combined. BMI and doctor-diagnosed asthma were modeled during the first 6 years of life with latent growth mixture modeling and discrete time hazard models. Subpopulations of children were identified with similar standardized BMI trajectories according to age- and sex-specific "World Health Organization (WHO) child growth standards" and "WHO growth standards for school aged children and adolescents" for children up to age 5 years and older than 5 years, respectively (BMI-SDS). These types of growth profiles were analyzed as predictors for incident asthma. RESULTS: Children with a rapid BMI-SDS gain in the first 2 years of life had a higher risk for incident asthma up to age 6 years than children with a less pronounced weight gain slope in early childhood. The hazard ratio was 1.3 (95% CI, 1.1-1.5) after adjustment for birth weight, weight-for-length at birth, gestational age, sex, maternal smoking in pregnancy, breast-feeding, and family history of asthma or allergies. A rapid BMI gain at 2 to 6 years of age in addition to rapid gain in the first 2 years of life did not significantly enhance the risk of asthma. CONCLUSION: Rapid growth in BMI during the first 2 years of life increases the risk of asthma up to age 6 years.

Maternal smoking in pregnancy and asthma in preschool children: a pooled analysis of eight birth cohorts.

RATIONALE: Although epidemiological studies suggest that exposure to maternal smoking during fetal and early life increases the risk of childhood wheezing and asthma, previous studies were not able to differentiate the effects of prenatal from postnatal exposure. OBJECTIVES: To assess the effect of exposure to maternal smoking only during pregnancy on wheeze and asthma among preschool-age children. METHODS: A pooled analysis was performed based on individual participant data from eight European birth cohorts. Cohort-specific effects of maternal smoking during pregnancy, but not during the first year, on wheeze and asthma at 4 to 6 years of age were estimated using logistic regression and then combined using a random effects model. Adjustments were made for sex, parental education, parental asthma, birth weight, and siblings. MEASUREMENTS AND MAIN RESULTS: Among the 21,600 children included in the analysis, 735 children (3.4%) were exposed to maternal smoking exclusively during pregnancy but not in the first year after birth. In the pooled analysis, maternal smoking only during pregnancy was associated with wheeze and asthma at 4 to 6 years of age, with adjusted odds ratios of 1.39 (95% confidence interval, 1.08-1.77) and 1.65 (95% confidence interval, 1.18-2.31), respectively. The likelihood to develop wheeze and asthma increased statistically significantly in a linear dose-dependent manner in relation to maternal daily cigarette consumption during the first trimester of pregnancy. CONCLUSIONS: Maternal smoking during pregnancy appears to increase the risk of wheeze and asthma among children who are not exposed to maternal smoking after birth.

DNA hypomethylation at ALOX12 is associated with persistent wheezing in childhood.

RATIONALE: Epigenetic changes may play a role in the occurrence of asthma-related phenotypes. OBJECTIVES: To identify epigenetic marks in terms of DNA methylation of asthma-related phenotypes in childhood, and to assess the effect of prenatal exposures and genetic variation on these epigenetic marks. METHODS: Data came from two cohorts embedded in the Infancia y Medio Ambiente (INMA) PROJECT: Menorca (n = 122) and Sabadell (n = 236). Wheezing phenotypes were defined at age 4-6 years. Cytosine-guanine (CpG) dinucleotide site DNA methylation differences associated with wheezing phenotypes were screened in children of the Menorca study using the Illumina GoldenGate Panel I. Findings were validated and replicated using pyrosequencing. Information on maternal smoking and folate supplement use was obtained through questionnaires. Dichlorodiphenyldichloroethylene was measured in cord blood or maternal serum. Genotypes were extracted from genome-wide data. MEASUREMENT AND MAIN RESULTS: Screening identified lower DNA methylation at a CpG site in the arachidonate 12-lipoxygenase (ALOX12) gene in children having persistent wheezing compared with those never wheezed (P = 0.003). DNA hypomethylation at ALOX12 loci was associated with higher risk of persistent wheezing in the Menorca study (odds ratio per 1% methylation decrease, 1.13; 95% confidence interval, 0.99-1.29; P = 0.077) and in the Sabadell study (odds ratio, 1.16; 95% confidence interval, 1.03-1.37; P = 0.017). Higher levels of prenatal dichlorodiphenyldichloroethylene were associated with DNA hypomethylation of ALOX12 in the Menorca study (P = 0.033), but not in the Sabadell study (P = 0.377). ALOX12 DNA methylation was strongly determined by underlying genetic polymorphisms. CONCLUSIONS: DNA methylation of ALOX12 may be an epigenetic biomarker for the risk of asthma-related phenotypes.

Knowledge and attitudes of primary healthcare patients regarding population-based screening for colorectal cancer.

ABSTRACT: BACKGROUND: The aim of this study was to assess the extent of knowledge of primary health care (PHC) patients about colorectal cancer (CRC), their attitudes toward population-based screening for this disease and gender differences in these respects. METHODS: A questionnaire-based survey of PHC patients in the Balearic Islands and some districts of the metropolitan area of Barcelona was conducted. Individuals between 50 and 69 years of age with no history of CRC were interviewed at their PHC centers. RESULTS: We analyzed the results of 625 questionnaires, 58% of which were completed by women. Most patients believed that cancer diagnosis before symptom onset improved the chance of survival. More women than men knew the main symptoms of CRC. A total of 88.8% of patients reported that they would perform the fecal occult blood test (FOBT) for CRC screening if so requested by PHC doctors or nurses. If the FOBT was positive and a colonoscopy was offered, 84.9% of participants indicated that they would undergo the procedure, and no significant difference by gender was apparent. Fear of having cancer was the main reason for performance of an FOBT, and also for not performing the FOBT, especially in women. Fear of pain was the main reason for not wishing to undergo colonoscopy. Factors associated with reluctance to perform the FOBT were: (i) the idea that that many forms of cancer can be prevented by exercise and, (ii) a reluctance to undergo colonoscopy if an FOBT was positive. Factors associated with reluctance to undergo colonoscopy were: (i) residence in Barcelona, (ii) ignorance of the fact that early diagnosis of CRC is associated with better prognosis, (iii) no previous history of colonoscopy, and (iv) no intention to perform the FOBT for CRC screening. CONCLUSION: We identified gaps in knowledge about CRC and prevention thereof in PHC patients from the Balearic Islands and the Barcelona region of Spain. If fears about CRC screening, and CRC per se, are addressed, and if it is emphasized that CRC is preventable, participation in CRC screening programs may improve.

Maternal use of folic acid supplements during pregnancy and four-year-old neurodevelopment in a population-based birth cohort.

The use of folic acid supplements during very early pregnancy is recommended in order to reduce the incidence of neural tube defects. Little is known about the possible benefits of folic acid on child neurodevelopment. A total of 420 children (87% of those eligible) from a birth cohort had complete data for final analyses at age 4 years. Information about folic acid and other over-the-counter dietary supplements was obtained prospectively using interviewer-administered questionnaires at the end of the first trimester of pregnancy. Psychological outcomes were assessed by two psychologists and teachers 4 years later. Low maternal socio-economic status, smoking, high parity and short duration of breast feeding were associated with lower prevalence of folic acid supplement use. Verbal (b = 3.98, SE = 1.69), motor (b = 4.54, SE = 1.66) and verbal-executive function (b = 3.97, SE = 1.68) scores, social competence (b = 3.97, SE = 1.61) and inattention symptom [OR = 0.46; 95% CI 0.22, 0.95] scores were associated with reported folic acid use. Reported folic acid supplement use during pregnancy was associated with improved neurodevelopment in children after adjusting for a number of sociodemographic and behavioural factors.