Liver, renal, genitourinary and diabetic ketoacidosis risks among new users of empagliflozin versus dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes: Post-authorization safety study based on multinational cohorts

AIM

To estimate risks of diabetic ketoacidosis (DKA), acute liver injury (ALI), acute kidney injury (AKI), chronic kidney disease (CKD), severe complications of urinary tract infection (UTI) and genital infection (GI) among patients with type 2 diabetes initiating empagliflozin versus those initiating a dipeptidyl peptidase-4 (DPP-4) inhibitor.

MATERIALS AND METHODS

In this large multinational, observational, new-user cohort study in UK, Danish and US healthcare data sources, patients initiated empagliflozin or a DPP-4 inhibitor between August 2014 and August 2019, were aged ≥18 years, and had ≥12 months' continuous health plan enrolment. Incidence rates by exposure and incidence rate ratios, adjusted for propensity-score deciles, were calculated.

RESULTS

In total, 64 599 empagliflozin initiators and 203 315 DPP-4 inhibitor initiators were included. There was an increased risk [pooled adjusted incidence rate ratios (95% confidence interval)] of DKA [2.19 (1.74-2.76)] and decreased risks of ALI [0.77 (0.50-1.19) in patients without predisposing conditions of liver disease; 0.70 (0.56-0.88) in all patients] and AKI [0.54 (0.41-0.73)]. In the UK data, there was an increased risk of GI [males: 4.04 (3.46-4.71); females: 3.24 (2.81-3.74)] and decreased risks of CKD [0.53 (0.43-0.65)] and severe complications of UTI [0.51 (0.37-0.72)]. The results were generally consistent in subgroup and sensitivity analyses.

CONCLUSIONS

Compared with DDP-4 inhibitor use, empagliflozin use was associated with increased risks of DKA and GI and decreased risks of ALI, AKI, CKD and severe complications of UTI. These associations are consistent with previous studies and known class effects of sodium-glucose cotransporter 2 inhibitors, including renoprotective effects and beneficial effects on alanine aminotransferase levels.

Prenatal and child vitamin D levels and allergy and asthma in childhood

BACKGROUND

Early-life vitamin D deficiency may impair immune system development contributing to allergy and asthma onset. Findings from prospective studies are inconsistent.

OBJECTIVE

To examine whether maternal and child vitamin D levels are associated with allergic and asthma-related symptoms throughout childhood in a Spanish birth cohort.

METHODS

25-Hydroxyvitamin D₃ (25(OH)D₃) levels were measured in the serum of pregnant women (N = 2525) and children (N = 803). Information on allergic and asthma-related symptoms was obtained from repeated questionnaires from 1 to 9 years.

RESULTS

A total of 19% of mothers and 24% of children had deficient 25(OH)D₃ levels (<20 ng/ml). Higher child 25(OH)D₃ levels at 4 years were associated with lower odds of atopic eczema from 4 to 9 years (adjusted odds ratio = 0.90; 95% CI = 0.84-0.97 per 5 ng/ml). Higher maternal and child 25(OH)D₃ levels were associated with a lower prevalence of late-onset wheezing at the limit of statistical significance (adjusted relative risk ratio (RRR_adj) = 0.86; 95% CI = 0.74-1.00 and RRR_adj = 0.76; 95% CI = 0.58-1.02 per 5 ng/ml, respectively). All the remaining associations were null.

CONCLUSION

Child 25(OH)D₃ levels at pre-school age are associated with a reduced odds of atopic eczema in later childhood and both maternal and child levels may reduce the prevalence of late-onset wheezing.

IMPACT

In this Spanish birth cohort, with a total of 19% of mothers and 24% of children with deficient levels of vitamin D, higher child vitamin D at 4 years of age was associated with reduced odds of atopic eczema up to 9 years. There was also some evidence that higher maternal and child vitamin D levels reduced the prevalence of late-onset wheezing. Although these findings need replication, they may imply optimal vitamin D levels at pre-school age to prevent atopic eczema.

In utero exposure to bisphenols and asthma, wheeze, and lung function in school-age children: a prospective meta-analysis of 8 European birth cohorts

BACKGROUND

In utero exposure to bisphenols, widely used in consumer products, may alter lung development and increase the risk of respiratory morbidity in the offspring. However, evidence is scarce and mostly focused on bisphenol A (BPA) only.

OBJECTIVE

To examine the associations of in utero exposure to BPA, bisphenol F (BPF), and bisphenol S (BPS) with asthma, wheeze, and lung function in school-age children, and whether these associations differ by sex.

METHODS

We included 3,007 mother-child pairs from eight European birth cohorts. Bisphenol concentrations were determined in maternal urine samples collected during pregnancy (1999-2010). Between 7 and 11 years of age, current asthma and wheeze were assessed from questionnaires and lung function by spirometry. Wheezing patterns were constructed from questionnaires from early to mid-childhood. We performed adjusted random-effects meta-analysis on individual participant data.

RESULTS

Exposure to BPA was prevalent with 90% of maternal samples containing concentrations above detection limits. BPF and BPS were found in 27% and 49% of samples. In utero exposure to BPA was associated with higher odds of current asthma (OR = 1.13, 95% CI = 1.01, 1.27) and wheeze (OR = 1.14, 95% CI = 1.01, 1.30) (p-interaction sex = 0.01) among girls, but not with wheezing patterns nor lung function neither in overall nor among boys. We observed inconsistent associations of BPF and BPS with the respiratory outcomes assessed in overall and sex-stratified analyses.

CONCLUSION

This study suggests that in utero BPA exposure may be associated with higher odds of asthma and wheeze among school-age girls.

Prenatal exposure to phthalates and phenols and preclinical vascular health during early adolescence

BACKGROUND AND AIM

Exposure to endocrine-disrupting chemicals may increase cardiovascular risk from early life, but studies in children have shown inconsistent results, most focused on analysis of single chemicals, and none included measures of micro-vascularization as early preclinical markers. This study aimed to evaluate the association between prenatal exposure to phthalates and phenols and macro- and microvascular health during early adolescence.

METHODS

Using data from a Spanish birth cohort (n = 416), prenatal exposure to eight phthalate metabolites and seven phenols (bisphenol A, four parabens, benzophenone-3, triclosan) were assessed using first and/or third trimester spot-urine concentrations. Macrovascular health (systolic and diastolic blood pressure (SBP and DBP, mmHg), pulse wave velocity (PWV, m/s)) and microvascular health (central retinal artery/vein equivalent (CRAE/CRVE, μm)), were measured at 11 years old. Linear regression models assessed associations for individual chemicals and Bayesian weighted quantile sum regression (BWQS) evaluated the overall association of the phthalate and phenol mixture with cardiovascular health.

RESULTS

In single exposure models, bisphenol-A was associated with decreased PWV (β per doubling of exposure = -0.06; 95% CI: -0.10, -0.01). Mono-iso-butyl phthalate was associated with an increase in CRAE (β = 1.89; 95% CI: 0.34, 3.44). Methyl- and butyl-parabens were associated with a decrease in CRVE (β = -0.71; 95% CI: -1.41, -0.01) and (β = -0.96; 95% CI: -1.57, -0.35), respectively. No statistically significant associations were observed between any of the exposures and SBP or DBP. BWQS models showed no evidence of associations between the phthalate and phenol mixture and any of the outcomes.

CONCLUSIONS

Our results provide little evidence to suggest that prenatal exposure to phthalates and phenols is associated with macro- or microvascular health during early adolescence, except a few associations with certain compounds. Errors in exposure measurement and reduced variability in cardiovascular measures at this early age limit our ability to draw strong conclusions.

Prenatal exposure to persistent organic pollutants and markers of obesity and cardiometabolic risk in Spanish adolescents

BACKGROUND

Prenatal exposure to persistent organic pollutants (POPs) has been linked to cardiometabolic (CM) risk factors in childhood, but there are no studies evaluating the persistence of these associations into adolescence, a period of relevant changes in endocrine-dependent organ systems and rapid increases in lean and fat mass. We examined the associations of prenatal POP exposures with body mass index (BMI) from age 4 to 18 years, and with other CM risk markers in adolescence.

METHODS

We analysed 379 children from the Spanish INMA-Menorca birth cohort study with measured cord blood POP concentrations. We calculated BMI z-scores at ages 4, 6, 11, 14 and 18 years using the WHO growth reference. Body fat % was measured at 11 and 18 years and waist-to-height ratio (WHtR) and blood pressure (BP) at 11, 14 and 18 years. We measured CM biomarkers in fasting blood collected at age 14 years and calculated a CM-risk score as the sum of the sex-, and age-specific z-scores for waist circumference, mean arterial BP, homeostatic model assessment of insulin resistance, fasting blood triglycerides, and high-density lipoprotein cholesterol (HDL-C) (n = 217). Generalised estimating equations and multivariate linear regression models assessed the associations with repeated and single time-point measures, respectively.

RESULTS

Hexachlorobenzene (HCB) exposure in the third tertile, compared to the first tertile, was associated with higher BMI (β = 0.24; 95% CI: 0.01, 0.47) and WHtR z-score (β = 0.27; 95% CI: 0.04, 0.51). A continuous increase in HCB was associated with an elevated body fat % (β per 10-fold increase = 4.21; 95% CI: 0.51, 7.92), systolic BP (β = 0.32; 95% CI: 0.02, 0.64) and diastolic BP z-score (β = 0.32; 95% CI: 0.02, 0.62) across all ages, and with higher CM-risk score (β = 1.59; 95% CI: 0.02, 3.18) and lipid biomarkers (total cholesterol, triglycerides and low-density lipoprotein cholesterol (LDL-C)) at 14 years. Dichlorodiphenyltrichloroethane (p,p'-DDT) exposure was non-monotonically associated with BMI and systolic BP. p,p'-DDE and Σ-polychlorinated biphenyls (PCBs) (sum of congeners 118, 138, 153, 180) were not associated with adiposity or BP. p,p'-DDT exposure was associated with an increased CM-risk score, and ΣPCBs concentrations with LDL-C in all adolescents and with total cholesterol only in girls (p-sex interaction = 0.05).

CONCLUSION

This first longitudinal study from 4 to 18 years suggests that the previously reported POP associations with child BMI persist later in adolescence and that prenatal POP exposures are associated with major risk factors for adult CM syndrome.

Maternal seafood consumption during pregnancy and child attention outcomes: a cohort study with gene effect modification by PUFA-related genes

BACKGROUND

There is a need to test the fetal programming theoretical framework in nutritional epidemiology. We evaluated whether maternal seafood intake during pregnancy was associated with 8-year-old attention outcomes after adjusting for previous child seafood intake and cognitive function. We also explored effect modification by several single nucleotide polymorphisms (SNPs) related with polyunsaturated fatty acid (PUFA) metabolism.

METHODS

Our final analyses included 1644 mother-child pairs from the prospective INMA (INfancia y Medio Ambiente) cohort study (Spain, recruitment between 2003 and 2008). We used food frequency questionnaires to assess prenatal and postnatal seafood consumption of the mother-child pairs. We evaluated attention function of the children through the computer-based Attention Network Test (ANT) and we used the number of omission errors and the hit reaction time standard error (HRT-SE). Parents reported child attention deficit hyperactivity disorder (ADHD) symptoms using the Revised Conners' Parent Rating Scale Short Form (CPRS-R: S). We measured seven candidate SNPs in a subsample of 845 children. We estimated associations using regression models, adjusting for family characteristics, child seafood intake and cognitive functions at early ages, and to explore SNP effect modifications.

RESULTS

Higher total seafood intake during early pregnancy was associated with a reduction of child ANT omission errors, 5th quintile (median = 854 g/week) vs 1st quintile (median = 195 g/week), incidence risk ratio (IRR) 0.76; 95% CI = 0.61, 0.94. Similar results were observed after adjusting the models for child seafood intake and previous cognitive status. Lean, large and small fatty fish showed similar results, and generally similar but less robust associations were observed with the other attention outcomes. Shellfish and canned tuna showed weaker associations. The association patterns were weaker in late pregnancy and null in child seafood consumption. Child rs1260326 (glucokinase regulator, GCKR) and child/maternal rs2281591 (fatty acid elongase 2, ELOVL2) polymorphisms showed nominal P-value for interactions <0.10 between total seafood intake and ANT outcomes.

CONCLUSIONS

After adjusting for previous child cognitive functions and child seafood intake, high pregnancy consumption (total, lean, small and large fatty fish) was independently associated with improvements of some 8-year-old attention outcomes. Genetic effect modification analyses suggest PUFA intake from seafood as a potential biological mechanism of such association.

Walnuts, Long-Chain Polyunsaturated Fatty Acids, and Adolescent Brain Development: Protocol for the Walnuts Smart Snack Dietary Intervention Trial

Background: Adolescence, when the most complex behaviors are refined to adult sophistication, represents a major window of opportunity and vulnerability for neuropsychological development. To support and protect this complex and active brain growth, different nutritional components considered essential need to be acquired from the diet. For instance, omega-3 fatty acids are mainly obtained from seafood, seeds, and walnuts. Known for their rich lipid profile, walnuts contain sizable amounts of an essential fatty acid, alpha-linolenic acid (ALA), the vegetable omega-3 fatty acid that is the precursor of two longer-chain omega-3 polyunsaturated fatty acids (omega-3 PUFA): docosahexaenoic (DHA) and eicosapentaenoic (EPA) acids. While there is growing evidence of neuropsychological improvements in the young developing brain associated with omega-3 PUFA intake, few studies have examined whether consuming walnuts during adolescence entails similar beneficial effects. There is a need to further explore the ways in which walnuts influence youthful brain function, particularly for the long-term. Thus, we designed the WALNUTs study (WSS), a population-based randomized controlled trial conducted in adolescents in Barcelona, Spain. We hypothesize that walnut intake will increase omega-3 PUFA tissue availability (particularly ALA) to a level that enhances the neuropsychological development during adolescence. Methodology/Design: We conducted a 6-month population-based randomized controlled trial in teenagers (n = 800) and we aimed to determine the effectiveness of the intervention (four walnuts per day, or 30 kernel g, ~1.5g of ALA) in enhancing brain neuropsychological and socio-emotional development compared to a control group with no walnut intervention. Before randomization, different neuropsychological tests were recorded for all participants, and blood samples (in a subsample of participants) were collected to measure omega-3 PUFA levels at baseline, and all again, after randomization and the intervention. The data is now collected and we will conduct linear regression models to assess the effect of the intervention. Discussion: The WALNUTs (WSS) study results will allow us to better understand the role of plant-based omega-3 PUFA intake from regular walnut consumption on neuropsychological development during adolescence. Results could be translated into nutritional public health recommendations targeting teenagers. Trial Registration: ClinicalTrials.gov, U.S. National Library of Medicine, National Institutes of Health # NCT02590848. Retrospectively registered 29/10/2015.

Association of Lifestyle Factors and Neuropsychological Development of 4-Year-Old Children

BACKGROUND

We aimed to assess how lifestyle factors such as diet, sleep, screen viewing, and physical activity, individually, as well as in a combined score, were associated with neuropsychological development in pre-school age children.

METHODS

We conducted a cross-sectional study in 1650 children of 4 years of age, from the Environment and Childhood Project (INMA) population-based birth cohorts in four regions of Spain. Children were classified per a childhood healthy lifestyle score (CHLS) with a range of 0 to 4 that included eating in concordance with the Mediterranean diet (1 point); reaching recommended sleep time (1 point); watching a maximum recommended screen time (1 point); and being physically active (1 point). The McCarthy Scales of Children's Abilities (MSCA) were used to test neuropsychological development. Multi-adjusted linear regression models were created to assess the association with the lifestyle factors individually and as a combined score.

RESULTS

CHLS was not associated with MSCA general cognitive score (1-point increment = -0.5, 95% CI: -1.2, 0.2). Analyzed by separate lifestyle factors, physical activity had a significant negative association with MSCA score and less TV/screen time had a negative association with MSCA score.

CONCLUSION

In this cross-sectional study, a combined score of lifestyle factors is not related to neuropsychological development at pre-school age.

Prenatal exposure to organochlorine compounds and lung function during childhood

INTRODUCTION

Prenatal exposure to organochlorine compounds (OCs) can increase the risk of reported respiratory symptoms in children. It remains unclear whether these compounds can also impact on lung function. We assessed the association between prenatal exposure to OCs and lung function during childhood.

METHODS

We included 1308 mother-child pairs enrolled in a prospective cohort study. Prenatal concentrations of p,p'-dichlorodiphenyltrichloroethane [p,p'-DDT], p,p'-dichlorodiphenyldichloroethylene [p,p'-DDE], hexachlorobenzene [HCB], and seven polychlorinated biphenyls [PCBs] were measured in cord blood. Spirometry was performed in the offspring at ages 4 (n = 636) and 7 years (n = 1192).

RESULTS

More than 80% of samples presented quantifiable levels of p,p'-DDE, HCB, PCB-138, PCB-153, and PCB-180; p,p'-DDE was the compound with the highest median concentrations. At 4 years, prenatal p,p'-DDE exposure was associated with a decrease in forced expiratory volume in 1 s (FEV₁) in all quartiles of exposure (e.g., third quartile [0.23-0.34 ng/mL]: β for FEV₁ -53.61 mL, 95% CI -89.87, -17.35, vs. the lowest). Prenatal p,p'-DDE levels also decreased forced vital capacity (FVC) and FEV₁/FVC, but associations did not reach statistical significance in most exposure quartiles. At 7 years, p,p'-DDE was associated with a decrease in FVC and FEV₁ in only the second quartile of exposure (e.g. β for FEV₁ -36.96 mL, 95% CI -66.22, -7.70, vs. the lowest). Prenatal exposure to HCB was associated with decreased FVC and FEV₁, but in only the second quartile and at 7 years (e.g. [0.07-0.14 ng/mL]: β for FEV₁ -25.79 mL, 95% CI -55.98, 4.39, vs. the lowest). PCBs were not consistently associated with lung function.

CONCLUSION

Prenatal exposure to p,p'-DDE may decrease lung function during childhood, especially FEV₁ and at medium levels of exposure. Further and deeper knowledge on the impact of environmental chemicals during pregnancy on lung development is needed.

Prenatal Omega-6:Omega-3 Ratio and Attention Deficit and Hyperactivity Disorder Symptoms

OBJECTIVE

To evaluate whether higher omega-6:omega-3 (n-6:n-3) long-chain polyunsaturated fatty acid ratio in cord plasma is associated with more symptoms of attention deficit and hyperactivity disorder (ADHD) at 4 and 7 years of age.

STUDY DESIGN

This study was based on a population-based birth cohort in Spain. N-6 arachidonic acid and n-3 eicosapentaenoic and docosahexaenoic acid concentrations were measured in cord plasma. At 4 years old, ADHD symptoms were reported by teachers through the ADHD Diagnostic and Statistical Manual of Mental Disorders, 4th ed checklist (n = 580). At 7 years old, ADHD symptoms were reported by parents through the Conners' Rating Scale-Revised (short form; n = 642). The ADHD variable was treated as continuous (score) and as dichotomous (symptom diagnostic criteria). Child and family general characteristics were prospectively collected through questionnaires. We applied pooled zero-inflated negative binomial and logistic regressions adjusted for covariates.

RESULTS

A higher omega-6:omega-3 long-chain polyunsaturated fatty acid ratio in cord plasma was associated with a higher ADHD index (incidence rate ratio, 1.13; 95% CI, 1.03, 1.23) at 7 years old. The association was not observed at 4 years old (incidence rate ratio, 1.04; 95% CI, 0.92-1.18). No associations were found using ADHD symptom diagnostic criteria.

CONCLUSIONS

High prenatal omega-6:omega-3 long-chain polyunsaturated fatty acid ratio preceded the appearance of subclinical ADHD symptoms during mid-childhood. Our findings suggest that maternal diet during pregnancy may modulate the risk to develop long-term ADHD symptoms in the offspring.

Association between Early Life Exposure to Air Pollution and Working Memory and Attention

BACKGROUND

Although previous studies have reported negative associations between exposure to air pollution and cognition, studies of the effects of prenatal and postnatal exposures in early childhood have been limited.

OBJECTIVES

We sought to assess the role exposure to fine particulate matter ([Formula: see text]) during different prenatal and postnatal windows may play in children's cognitive development at school age.

METHODS

Within the Brain Development and Air Pollution Ultrafine Particles in School Children (BREATHE) Project, we estimated residential [Formula: see text] exposures by land use regression for the prenatal period and first seven postnatal years of 2,221 children from Barcelona, Spain. The participants ([Formula: see text]) completed computerized tests assessing working memory, attentiveness, and conflict network during four visits in 2012–2013. We used linear mixed effects and distributed lag models to assess the period of exposure to [Formula: see text] in association with cognitive development.

RESULTS

Inverse associations were identified between [Formula: see text] exposure during the fifth and sixth postnatal years and working memory, with boys showing much higher vulnerability. Regarding attention functions, exposure to higher [Formula: see text] levels during the prenatal period and from the fourth postnatal year were associated with a reduction in conflict network performance, though we found no association with attentiveness. The overall estimated cumulative effect of a [Formula: see text] increase in [Formula: see text] resulted in a reduction in the working memory [Formula: see text] score of [Formula: see text] [95% confidence interval (CI): [Formula: see text], [Formula: see text]] points and an increase in the conflict attentional network of 11.31 (95% CI: 6.05, 16.57) milliseconds, indicating a poorer performance.

CONCLUSIONS

Early life exposure to [Formula: see text] was associated with a reduction in fundamental cognitive abilities, including working memory and conflict attentional network. https://doi.org/10.1289/EHP3169.

Longitudinal association between air pollution exposure at school and cognitive development in school children over a period of 3.5 years

INTRODUCTION

Recently, we showed that exposure to traffic-related air pollutants (TRAPs) at school was negatively associated with cognitive development, specifically working memory and inattentiveness, in primary schoolchildren during a course of 12 months. The persistence of such associations over longer periods remains as an open question.

OBJECTIVE

To study the longitudinal association between TRAPs at school and cognitive development over a period of 3.5 years.

METHODS

Indoor and outdoor levels of TRAPs (elemental carbon (EC), dioxide nitrogen (NO₂), particulate matter (PM_2.5) from traffic sources and ultrafine particles (UFP)) were measured at 39 schools across Barcelona during 2012/2013. Working memory, as a measure of cognitive development, was evaluated 4 times in 2012/2013 assessment and was re-evaluated one more time in 2015 using computerized n-back test (3-back d' as main outcome). Linear mixed effects models were used to test the association between TRAPs and 3-back d', adding child and school as random effects to account for the multilevel nature of the data, and school air pollutants levels (one at a time) as predictor.

RESULTS

We found detrimental associations between all TRAPs and annual change in 3-back d' (working memory) (i.e. slower development of working memory in children attending schools with higher levels of air pollution). The associations (per one interquartile range increase in exposure) were strongest for outdoor NO₂ (Coefficient (Coef) = - 4.22, 95% confidence interval (CI), - 6.22, - 2.22) and indoor UFP (Coef = - 4.12, 95%CI, - 5.68, - 1.83). These reductions were equivalent to - 20% (95%CI, - 30.1, - 10.7) and - 19.9% (95%CI, - 31.5, - 8.4) change in annual working memory development associated with one interquartile range increase in outdoor NO₂ and indoor UFP, respectively.

CONCLUSION

Our findings suggest the persistence of the negative association between TRAPs exposure at school and cognitive trajectory measured by n-back test over a period of 3.5 years.

Ultrafine particles and black carbon personal exposures in asthmatic and non-asthmatic children at school age

Traffic-related air pollution (TRAP) exposure during childhood is associated with asthma; however, the contribution of the different TRAP pollutants in each microenvironment (home, school, transportation, others) in asthmatic and non-asthmatic children is unknown. Daily (24-h) personal black carbon (BC), ultrafine particle (UFP), and alveolar lung-deposited surface area (LDSA) individual exposure measurements were obtained from 100 children (29 past and 21 current asthmatics, 50 non-asthmatics) aged 9±0.7 years from the INMA-Sabadell cohort (Catalonia, Spain). Time spent in each microenvironment was derived by the geolocation provided by the smartphone and a new spatiotemporal map-matching algorithm. Asthmatics and non-asthmatics spent the same amount of time at home (60% and 61%, respectively), at school (20% and 23%), on transportation (8% and 7%), and in other microenvironments (7% and 5%). The highest concentrations of all TRAPs were attributed to transportation. No differences in TRAP concentrations were found overall or by type of microenvironment between asthmatics and non-asthmatics, nor when considering past and current asthmatics, separately. In conclusion, asthmatic and non-asthmatic children had a similar time-activity pattern and similar average exposures to BC, UFP, and LDSA concentrations. This suggests that interventions should be tailored to general population, rather than to subgroups defined by disease.

Association between breastfeeding duration and cognitive development, autistic traits and ADHD symptoms: a multicenter study in Spain

BACKGROUND

Several studies have related longer breastfeeding duration to better intellectual performance in children. By contrast, few studies have investigated the potential protective effects of breastfeeding against behavioral problems such as attention deficit hyperactivity disorder (ADHD) symptoms, and even fewer on autism spectrum disorders (ASD) traits.

METHODS

We examined the association between breastfeeding duration and cognitive development, attention, ADHD symptoms, and autistic traits using data from the INMA Project, a Spanish multicenter birth-cohort study, and taking into account the intensity of breastfeeding. Duration of any, predominant, and exclusive breastfeeding was documented during infancy through maternal questionnaires. Children (N = 1,346; mean age = 4.9 y) were assessed using the McCarthy Scales of Children's Abilities, Conners' Kiddie Continuous Performance Test, criteria of the DSM-ADHD symptoms form list, and the Childhood Autism Spectrum Test.

RESULTS

After adjustment for several confounders, longer duration of breastfeeding was independently associated with better cognitive development and with fewer autistic traits.

CONCLUSION

This study provides further evidence of a positive association of breastfeeding with cognitive function apart from socio-environmental factors, and also suggests a protective role against autistic traits. Results are in agreement with recommendations for prolonged breastfeeding duration to promote child development.

Traffic-Related Air Pollution, Noise at School, and Behavioral Problems in Barcelona Schoolchildren: A Cross-Sectional Study

BACKGROUND

The available evidence of the effects of air pollution and noise on behavioral development is limited, and it overlooks exposure at schools, where children spend a considerable amount of time.

OBJECTIVE

We aimed to investigate the associations of exposure to traffic-related air pollutants (TRAPs) and noise at school on behavioral development of schoolchildren.

METHODS

We evaluated children 7-11 years of age in Barcelona (Catalonia, Spain) during 2012-2013 within the BREATHE project. Indoor and outdoor concentrations of elemental carbon (EC), black carbon (BC), and nitrogen dioxide (NO2) were measured at schools in two separate 1-week campaigns. In one campaign we also measured noise levels inside classrooms. Parents filled out the strengths and difficulties questionnaire (SDQ) to assess child behavioral development, while teachers completed the attention deficit/hyperactivity disorder criteria of the DSM-IV (ADHD-DSM-IV) list to assess specific ADHD symptomatology. Negative binomial mixed-effects models were used to estimate associations between the exposures and behavioral development scores.

RESULTS

Interquartile range (IQR) increases in indoor and outdoor EC, BC, and NO2 concentrations were positively associated with SDQ total difficulties scores (suggesting more frequent behavioral problems) in adjusted multivariate models, whereas noise was significantly associated with ADHD-DSM-IV scores.

CONCLUSION

In our study population of 7- to 11-year-old children residing in Barcelona, exposure to TRAPs at school was associated with increased behavioral problems in schoolchildren. Noise exposure at school was associated with more ADHD symptoms.

CITATION

Forns J, Dadvand P, Foraster M, Alvarez-Pedrerol M, Rivas I, López-Vicente M, Suades-Gonzalez E, Garcia-Esteban R, Esnaola M, Cirach M, Grellier J, Basagaña X, Querol X, Guxens M, Nieuwenhuijsen MJ, Sunyer J. 2016. Traffic-related air pollution, noise at school, and behavioral problems in Barcelona schoolchildren: a cross-sectional study. Environ Health Perspect 124:529-535; http://dx.doi.org/10.1289/ehp.1409449.

Exposure to Bisphenol A and Phthalates during Pregnancy and Ultrasound Measures of Fetal Growth in the INMA-Sabadell Cohort

BACKGROUND

Prenatal exposure to bisphenol A (BPA) and phthalates may affect fetal growth; however, previous findings are inconsistent and based on few studies.

OBJECTIVES

We assessed whether prenatal exposure to BPA and phthalates was associated with fetal growth in a Spanish birth cohort of 488 mother-child pairs.

METHODS

We measured BPA and eight phthalates [four di(2-ethylhexyl) phthalate metabolites (DEHPm), mono-benzyl phthalate (MBzP), and three low-molecular-weight phthalate metabolites (LMWPm)] in two spot-urine samples collected during the first and third trimester of pregnancy. We estimated growth curves for femur length (FL), head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), and estimated fetal weight (EFW) during pregnancy (weeks 12-20 and 20-34), and for birth weight, birth length, head circumference at birth, and placental weight.

RESULTS

Overall, results did not support associations of exposure to BPA or DEHPm during pregnancy with fetal growth parameters. Prenatal MBzP exposure was positively associated with FL at 20-34 weeks, resulting in an increase of 3.70% of the average FL (95% CI: 0.75, 6.63%) per doubling of MBzP concentration. MBzP was positively associated with birth weight among boys (48 g; 95% CI: 6, 90) but not in girls (-27 g; 95% CI: -79, 25) (interaction p-value = 0.04). The LMWPm mono-n-butyl phthalate (MnBP) was negatively associated with HC at 12-20 pregnancy weeks [-4.88% of HC average (95% CI: -8.36, -1.36%)].

CONCLUSIONS

This study, one of the first to combine repeat exposure biomarker measurements and multiple growth measures during pregnancy, finds little evidence of associations of BPA or phthalate exposures with fetal growth. Phthalate metabolites MBzP and MnBP were associated with some fetal growth parameters, but these findings require replication.

CITATION

Casas M, Valvi D, Ballesteros-Gomez A, Gascon M, Fernández MF, Garcia-Esteban R, Iñiguez C, Martínez D, Murcia M, Monfort N, Luque N, Rubio S, Ventura R, Sunyer J, Vrijheid M. 2016. Exposure to bisphenol A and phthalates during pregnancy and ultrasound measures of fetal growth in the INMA-Sabadell cohort. Environ Health Perspect 124:521-528; http://dx.doi.org/10.1289/ehp.1409190.

Air Pollution Exposure during Pregnancy and Childhood Autistic Traits in Four European Population-Based Cohort Studies: The ESCAPE Project

BACKGROUND

Prenatal exposure to air pollutants has been suggested as a possible etiologic factor for the occurrence of autism spectrum disorder.

OBJECTIVES

We aimed to assess whether prenatal air pollution exposure is associated with childhood autistic traits in the general population.

METHODS

Ours was a collaborative study of four European population-based birth/child cohorts-CATSS (Sweden), Generation R (the Netherlands), GASPII (Italy), and INMA (Spain). Nitrogen oxides (NO2, NOx) and particulate matter (PM) with diameters of ≤ 2.5 μm (PM2.5), ≤ 10 μm (PM10), and between 2.5 and 10 μm (PM(coarse)), and PM2.5 absorbance were estimated for birth addresses by land-use regression models based on monitoring campaigns performed between 2008 and 2011. Levels were extrapolated back in time to exact pregnancy periods. We quantitatively assessed autistic traits when the child was between 4 and 10 years of age. Children were classified with autistic traits within the borderline/clinical range and within the clinical range using validated cut-offs. Adjusted cohort-specific effect estimates were combined using random-effects meta-analysis.

RESULTS

A total of 8,079 children were included. Prenatal air pollution exposure was not associated with autistic traits within the borderline/clinical range (odds ratio = 0.94; 95% CI: 0.81, 1.10 per each 10-μg/m3 increase in NO2 pregnancy levels). Similar results were observed in the different cohorts, for the other pollutants, and in assessments of children with autistic traits within the clinical range or children with autistic traits as a quantitative score.

CONCLUSIONS

Prenatal exposure to NO2 and PM was not associated with autistic traits in children from 4 to 10 years of age in four European population-based birth/child cohort studies.

CITATION

Guxens M, Ghassabian A, Gong T, Garcia-Esteban R, Porta D, Giorgis-Allemand L, Almqvist C, Aranbarri A, Beelen R, Badaloni C, Cesaroni G, de Nazelle A, Estarlich M, Forastiere F, Forns J, Gehring U, Ibarluzea J, Jaddoe VW, Korek M, Lichtenstein P, Nieuwenhuijsen MJ, Rebagliato M, Slama R, Tiemeier H, Verhulst FC, Volk HE, Pershagen G, Brunekreef B, Sunyer J. 2016. Air pollution exposure during pregnancy and childhood autistic traits in four European population-based cohort studies: the ESCAPE Project. Environ Health Perspect 124:133-140; http://dx.doi.org/10.1289/ehp.1408483.

Exposure to Endocrine-Disrupting Chemicals during Pregnancy and Weight at 7 Years of Age: A Multi-pollutant Approach

BACKGROUND

Prenatal exposure to endocrine-disrupting chemicals (EDCs) may induce weight gain and obesity in children, but the obesogenic effects of mixtures have not been studied.

OBJECTIVE

We evaluated the associations between pre- and perinatal biomarker concentrations of 27 EDCs and child weight status at 7 years of age.

METHODS

In pregnant women enrolled in a Spanish birth cohort study between 2004 and 2006, we measured the concentrations of 10 phthalate metabolites, bisphenol A, cadmium, arsenic, and lead in two maternal pregnancy urine samples; 6 organochlorine compounds in maternal pregnancy serum; mercury in cord blood; and 6 polybrominated diphenyl ether congeners in colostrum. Among 470 children at 7 years, body mass index (BMI) z-scores were calculated, and overweight was defined as BMI > 85th percentile. We estimated associations with EDCs in single-pollutant models and applied principal-component analysis (PCA) on the 27 pollutant concentrations.

RESULTS

In single-pollutant models, HCB (hexachlorobenzene), βHCH (β-hexachlorocyclohexane), and polychlorinated biphenyl (PCB) congeners 138 and 180 were associated with increased child BMI z-scores; and HCB, βHCH, PCB-138, and DDE (dichlorodiphenyldichloroethylene) with overweight risk. PCA generated four factors that accounted for 43.4% of the total variance. The organochlorine factor was positively associated with BMI z-scores and with overweight (adjusted RR, tertile 3 vs. 1: 2.59; 95% CI: 1.19, 5.63), and these associations were robust to adjustment for other EDCs. Exposure in the second tertile of the phthalate factor was inversely associated with overweight.

CONCLUSIONS

Prenatal exposure to organochlorines was positively associated with overweight at age 7 years in our study population. Other EDCs exposures did not confound this association.

Early-life house dust mite allergens, childhood mite sensitization, and respiratory outcomes

BACKGROUND

Exposure to indoor allergens during early life may play a role in the development of the immune system and inception of asthma.

OBJECTIVE

To describe the house dust mite (HDM) allergen concentrations in bedroom dust during early life and to evaluate its associations with HDM sensitization, wheezing, and asthma, from birth to school age, in 5 geographically spread European birth cohorts.

METHODS

We included 4334 children from INMA-Menorca (Spain), BAMSE (Sweden), LISAplus and MAS (Germany), and PIAMA-NHS (the Netherlands). Dust samples were collected from bedrooms during early life and analyzed for Dermatophagoides pteronyssinus (Der p1) and Dermatophagoides farinae (Der f1). HDM concentrations were divided into four categories. Sensitization was determined by specific IgE. Wheezing and asthma information up to 8/10 years was collected through questionnaires. We performed mixed-effects logistic regression models and expressed associations as odds ratios with 95% confidence intervals.

RESULTS

House dust mite concentrations varied across cohorts. Mean allergen concentrations were highest in INMA-Menorca (geometric mean (GM) Der p1 = 3.3 μg/g) and LISAplus (GM Der f1 = 2.1 μg/g) and lowest in BAMSE (GM Der p1 = 0.1 μg/g, Der f1 = 0.3 μg/g). Moderate and high HDM concentrations were significantly (P-values < 0.05) associated with 50-90% higher prevalence of HDM sensitization. No significant associations were observed with respiratory outcomes.

CONCLUSION

Our study based on geographically spread regions, a large sample size, and a wide range of allergen concentration shows that HDM allergen concentrations vary across regions and that exposure during early life plays a role in the development of allergic sensitization but not in the development of respiratory outcomes.

Prenatal head growth and child neuropsychological development at age 14 months

OBJECTIVE

We sought to assess the association between prenatal head growth and child neuropsychological development in the general population.

STUDY DESIGN

We evaluated 2104 children at the age of 14 months from a population-based birth cohort in Spain. Head circumference (HC) was measured by ultrasound examinations at weeks 12, 20, and 34 of gestation and by a nurse at birth. Head growth was assessed using conditional SD scores between weeks 12-20 and 20-34. Trained psychologists assessed neuropsychological functioning using the Bayley Scales of Infant Development. Head size measurements at birth were transformed into a 3-category variable: microcephalic (<10th percentile), normocephalic (≥10th and <90th percentile), and macrocephalic (≥90th percentile) based on the cohort distribution. P values<.05 were considered statistically significant.

RESULTS

No overall associations were observed between HC or head growth and mental and psychomotor scores. In particular, no associations were found between HC at birth and mental scores (coefficient, 0.04; 95% confidence interval, -0.02 to 0.09) and between interval head growth (20-34 weeks) and mental scores (0.31; 95% confidence interval, -0.36 to 0.99). Upon stratification by microcephalic, normocephalic, or macrocephalic head size, results were imprecise, although there were some significant associations in the microcephalic and macrocephalic groups. Adjustment by various child and maternal cofactors did not affect results. The minimum sample size required for present study was 883 patients (β=2, α=0.05, power=0.80).

CONCLUSION

Overall prenatal and perinatal HC was not associated with 14-month-old neuropsychological development. Findings suggest HC growth during uterine life among healthy infants may not be an important marker of early-life neurodevelopment but may be marginally useful with specific populations.

Association between traffic-related air pollution in schools and cognitive development in primary school children: a prospective cohort study

BACKGROUND

Air pollution is a suspected developmental neurotoxicant. Many schools are located in close proximity to busy roads, and traffic air pollution peaks when children are at school. We aimed to assess whether exposure of children in primary school to traffic-related air pollutants is associated with impaired cognitive development.

METHODS AND FINDINGS

We conducted a prospective study of children (n = 2,715, aged 7 to 10 y) from 39 schools in Barcelona (Catalonia, Spain) exposed to high and low traffic-related air pollution, paired by school socioeconomic index; children were tested four times (i.e., to assess the 12-mo developmental trajectories) via computerized tests (n = 10,112). Chronic traffic air pollution (elemental carbon [EC], nitrogen dioxide [NO2], and ultrafine particle number [UFP; 10-700 nm]) was measured twice during 1-wk campaigns both in the courtyard (outdoor) and inside the classroom (indoor) simultaneously in each school pair. Cognitive development was assessed with the n-back and the attentional network tests, in particular, working memory (two-back detectability), superior working memory (three-back detectability), and inattentiveness (hit reaction time standard error). Linear mixed effects models were adjusted for age, sex, maternal education, socioeconomic status, and air pollution exposure at home. Children from highly polluted schools had a smaller growth in cognitive development than children from the paired lowly polluted schools, both in crude and adjusted models (e.g., 7.4% [95% CI 5.6%-8.8%] versus 11.5% [95% CI 8.9%-12.5%] improvement in working memory, p = 0.0024). Cogently, children attending schools with higher levels of EC, NO2, and UFP both indoors and outdoors experienced substantially smaller growth in all the cognitive measurements; for example, a change from the first to the fourth quartile in indoor EC reduced the gain in working memory by 13.0% (95% CI 4.2%-23.1%). Residual confounding for social class could not be discarded completely; however, the associations remained in stratified analyses (e.g., for type of school or high-/low-polluted area) and after additional adjustments (e.g., for commuting, educational quality, or smoking at home), contradicting a potential residual confounding explanation.

CONCLUSIONS

Children attending schools with higher traffic-related air pollution had a smaller improvement in cognitive development.

Early exposure to bio-contaminants and asthma up to 10 years of age: results of the HITEA study

Inverse associations have been found between exposure to bio-contaminants and asthma and allergies. The aim of this study was to prospectively assess whether early exposure to bio-contaminants in dust is associated with asthma and allergy later in childhood among children from (sub)-urban areas. In subsets of three European birth cohorts (PIAMA: n=553; INMA: n=481; and LISAplus: n=395), endotoxin, (1,3,)-β-d-glucan and extracellular polysaccharide were measured in dust from living rooms shortly after birth. Current asthma at 6 years and 10 years of age and ever asthma up to 10 years of age were assessed by parental questionnaires. Specific IgE levels at 8 years (PIAMA) and 10 years (LISAplus) were available. Adjusted, cohort-specific logistic regression analyses were performed. Higher endotoxin concentrations were positively associated with current asthma at 6 years of age in PIAMA (adjusted OR 1.96, 95% CI 1.07-3.58), but were inversely related with ever asthma up to 10 years of age in INMA (adjusted OR 0.39, 95% CI 0.16-0.94). No associations with asthma were found for LISAplus. No associations were observed with atopic sensitisation in all cohorts. All associations with (1,3)-β-d-glucan and extracellular polysaccharide were statistically nonsignificant. The suggested immunological mechanisms of early exposure to bio-contaminants with regards to asthma and allergy might be different for children growing up in (sub)-urban environments.

Association between child cortisol levels in saliva and neuropsychological development during the second year of life

Exposure to highly elevated levels of cortisol has been linked with impairments in cognitive capacities in both children and adults. By contrast, moderate levels of cortisol may engender beneficial effects. The main aim of this study was to assess the association between child cortisol levels and neuropsychological development during the second year of life. A population-based birth cohort was established in the city of Sabadell (Catalonia, Spain) as part of the INMA (Environment and Childhood) Project. We assessed the cognitive and psychomotor development at the age of 14 months using the Bayley Scales of Infant Development (BSID). We included 302 children assessed during their second year of life for whom we had information on neuropsychological assessment and measurements of cortisol in saliva. Higher levels of cortisol were associated with better scores in BSID's mental scale. There was no association between cortisol levels and psychomotor test scores. We found a small positive association between duration of breastfeeding and child cortisol levels. This association was only found in boys. The results of this study suggest that moderate levels of cortisol in children could have small beneficial effects on their early neuropsychological development.

Prenatal exposure to persistent organic pollutants and rapid weight gain and overweight in infancy

OBJECTIVE

To examine the effects of prenatal exposure to persistent organic pollutants (POPs) on rapid growth in the first 6 months of life and overweight at 14 months of age.

DESIGN AND METHODS

In a Spanish birth cohort study, the POPs dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs-congeners 153, 138, 180) were measured in maternal serum collected in the first trimester of pregnancy during 2003-2008. Rapid growth was defined as a z-score weight gain >0.67 SD between 6 months of age and birth. Overweight at 14 months was defined as a BMI z-score ≥85th percentile. Generalized linear models examined the association between POPs and rapid growth (N = 1285) and overweight (N = 1198).

RESULTS

The analysis population included 24% rapid growers and 30% overweight infants. DDE and HCB were positively associated with rapid growth and with overweight. There was some indication that infant sex and exclusive breastfeeding duration may modify the effects of DDE, and that maternal prepregnancy BMI status may influence the effects of HCB. PCBs were not related to postnatal growth.

CONCLUSION

Prenatal exposure to DDE and HCB may be associated with early postnatal growth. Further research is needed to evaluate the persistence of these associations at older ages.

Early life microbial exposure and fractional exhaled nitric oxide in school-age children: a prospective birth cohort study

BACKGROUND

Inflammation is a key factor in the pathogenesis of respiratory diseases. Early life exposure to microbial agents may have an effect on the development of the immune system and on respiratory health later in life.In the present work we aimed to evaluate the associations between early life microbial exposures, and fractional exhaled nitric oxide (FeNO) at school age.

METHODS

Endotoxin, extracellular polysaccharides (EPS) and β(1,3)-D-glucan were measured in living room dust collected at 2-3 months of age in homes of participants of three prospective European birth cohorts (LISA, n = 182; PIAMA, n = 244; and INMA, n = 355). Home dampness and pet ownership were periodically reported by the parents through questionnaires. FeNO was measured at age 8 for PIAMA and at age 10/11 for LISA and INMA. Cohort-specific associations between the indoor microbial exposures and FeNO were evaluated using multivariable regression analyses. Estimates were combined using random-effects meta-analyses.

RESULTS

FeNO at school age was lower in children exposed to endotoxin at age 2-3 months (β -0.05, 95% confidence interval (CI) -0.10;-0.01) and in children with reported dog ownership during the first two years of life (GM ratio 0.82, CI 0.70-0.96). FeNO was not significantly associated with early life exposure to EPS, β(1,3)-D-glucan, indoor dampness and cat ownership.

CONCLUSION

Early life exposure to bacterial endotoxin and early life dog ownership are associated with lower FeNO at school age. Further studies are needed to confirm our results and to unravel the underlying mechanisms and possible clinical relevance of this finding.

Endotoxin, extracellular polysaccharides, and β(1-3)-glucan concentrations in dust and their determinants in four European birth cohorts: results from the HITEA project

Early-life exposure to microbial agents may play a protective role in asthma and allergies development. Geographical differences in the prevalence of these diseases exist, but the differences in early-life indoor microbial agent levels and their determinants have been hardly studied. We aimed to describe the early-life levels of endotoxin, extracellular polysaccharides (EPS), and β(1-3)-glucans in living room dust of four geographically spread European birth cohorts (LISA in Germany, PIAMA in the Netherlands, INMA in Spain, and LUKAS2 in Finland) and to assess their determinants. A total of 1572 dust samples from living rooms of participants were analyzed for endotoxin, Penicillium/Aspergillus EPS, and β(1-3)-glucans. Information on potential determinants was obtained through questionnaires. Concentrations of endotoxin, EPS, and β(1-3)-glucans were different across cohorts. Concentrations of endotoxin and EPS were respectively lower and higher in INMA than in other cohorts, while glucans were higher in LUKAS2. Season of sampling, dog ownership, dampness, and the number of people living at home were significantly associated with concentrations of at least one microbial agent, with heterogeneity of effect estimates of the determinants across cohorts. In conclusion, both early-life microbial exposure levels and exposure determinants differ across cohorts derived from diverse European countries.

PRACTICAL IMPLICATIONS

This study adds evidence of variability in the levels of indoor endotoxin, extracellular polysaccharide, and β(1-3)-glucans across four geographically spread European regions. Furthermore, we observed heterogeneity across regions in the effect of exposure determinants. We hypothesize that the variations observed in our study may play a role in the differences in asthma and allergies prevalences across countries.

Early-life exposure to outdoor air pollution and respiratory health, ear infections, and eczema in infants from the INMA study

BACKGROUND

Prenatal and early-life periods may be critical windows for harmful effects of air pollution on infant health.

OBJECTIVES

We studied the association of air pollution exposure during pregnancy and the first year of life with respiratory illnesses, ear infections, and eczema during the first 12-18 months of age in a Spanish birth cohort of 2,199 infants.

METHODS

We obtained parentally reported information on doctor-diagnosed lower respiratory tract infections (LRTI) and parental reports of wheezing, eczema, and ear infections. We estimated individual exposures to nitrogen dioxide (NO(2)) and benzene with temporally adjusted land use regression models. We used log-binomial regression models and a combined random-effects meta-analysis to estimate the effects of air pollution exposure on health outcomes across the four study locations.

RESULTS

A 10-µg/m(3) increase in average NO(2) during pregnancy was associated with LRTI [relative risk (RR) = 1.05; 95% CI: 0.98, 1.12] and ear infections (RR = 1.18; 95% CI: 0.98, 1.41). The RRs for an interquartile range (IQR) increase in NO(2) were 1.08 (95% CI: 0.97, 1.21) for LRTI and 1.31 (95% CI: 0.97, 1.76) for ear infections. Compared with NO(2), the association for an IQR increase in average benzene exposure was similar for LRTI (RR = 1.06; 95% CI: 0.94, 1.19) and slightly lower for ear infections (RR = 1.17; 95% CI: 0.93, 1.46). Associations were slightly stronger among infants whose mothers spent more time at home during pregnancy. Air pollution exposure during the first year was highly correlated with prenatal exposure, so we were unable to discern the relative importance of each exposure period.

CONCLUSIONS

Our findings support the hypothesis that early-life exposure to ambient air pollution may increase the risk of upper and lower respiratory tract infections in infants.

Male specific association between xenoestrogen levels in placenta and birthweight

BACKGROUND

Fetal exposure to endocrine disrupting chemicals may increase the risk for adverse health effects at birth or later in life.

OBJECTIVES

The objective of this study is to analyze the combined effect of xenoestrogens on reproductive and perinatal growth outcomes (child birthweight, early rapid growth and body mass index (BMI) at 14 months) using the biomarker total effective xenoestrogen burden (TEXB).

METHODS

490 placentas were randomly collected in the Spanish prospective birth cohort Environment and Childhood (INMA) project. TEXB was used to assess the estrogenicity of placental samples in two fractions: that largely attributable to environmental organohalogenated xenoestrogens (TEXB-alpha), and that mostly due to endogenous estrogens (TEXB-beta), both expressed in estrogen equivalent units (Eeq) per gram of tissue. Linear or logistic regression models were performed adjusting for cohort and confounders. Sex interactions were investigated.

RESULTS

The median TEXB-alpha level was 0.76 pM Eeq/g (interquartile range (iqr): 1.14). In multivariate models, higher TEXB-alpha levels (third tertile, >1.22 pM Eeq/g; iqr: 1.73) were associated with increased birthweight in boys but not in girls (β=148.2 g, 95% CI: 14.01, 282.53, p(int)=0.057). Additionally, higher TEXB-alpha values in boys were related with a lower risk of early rapid growth (OR=0.37; 95% CI: 0.15, 0.88) and with a non significant association with larger BMI z-scores at 14 months of age (β=0.29; 95% CI: -0.11, 0.69).

CONCLUSIONS

These findings suggest that prenatal exposure to xenoestrogens may increase birthweight in boys, which might have an impact on child obesity and other later health outcomes.

Prenatal exposure to polychlorinated biphenyls and child neuropsychological development in 4-year-olds: an analysis per congener and specific cognitive domain

Polychlorinated biphenyls (PCB) are synthetic organochlorine compounds with potential neurotoxic effects. Although negative effects on neuropsychological development have been observed in previous studies on PCB exposure, there are inconsistencies in these effects at current exposure levels of these compounds which are much lower than for previous generations. This study aimed to disentangle the effects of prenatal and postnatal PCB exposure on neuropsychological development at 4 years of age. This study is based on a population-based birth cohort design established in Menorca (Spain) as part of the INMA [Environment and Childhood] Project. We assessed general neuropsychological development using the McCarthy Scales of Children's Abilities (MCSA). A total of 422 4-year old children were assessed with the MCSA. Levels of PCBs were measured in cord blood (n=405) and in blood samples taken at 4 years (n=285). We found no statistically significant effects of the sum of prenatal PCBs on MCSA scores. Nevertheless, individual congener analyses yielded significant detrimental effects of prenatal PCB153 on the majority of MCSA scores, while no effects were reported for other congeners. The levels of PCBs at 4 years of age were not associated with neuropsychological development. Thus, prenatal exposure to low-level concentrations of PCBs, particularly PCB153, was associated with an overall deleterious effect on neuropsychological development at 4 years of age, including negative effects on executive function, verbal functions and visuospatial abilities, but not on motor development.

Longitudinal association between early life socio-environmental factors and attention function at the age 11 years

Prenatal and early-life exposures can affect the course of children's neuropsychological development well into pre-adolescence, given the vulnerability of the developing brain. However, it is unknown which socio-environmental factors at early childhood can influence specific cognitive processes like attention at a later age. In this study, we aim to determine social and environmental exposures in early childhood that may be associated with attention function of 11-year-olds. We measured attention function using the continuous performance test-II (CPT-II) on 393 11-year old children from the Menorca's birth-cohort within the INMA-project (Spain), and pre-selected a list of socio-environmental observations taken when they were up to 4 years of age. We found that earlier socio-environmental characteristics, such as parental social class, educational level and maternal mental health are associated with later inattentive and impulsive symptomatology through a higher rate of omission and commission errors. In addition, omission errors were higher in children with atopy and lower in those whose mothers took dietary supplementation with folic acid and vitamins during pregnancy. Breastfeeding played a protective role against commission errors, while higher DDE and PCBs levels at age 4 were associated with slow speed response. Our findings suggest that a number of life socio-environmental factors during prenatal life and early childhood, such as socio-demographic characteristics, breastfeeding, maternal nutritional supplementation with folic acid and vitamins and exposure to some organochlorine compounds may influence inattentive and hyperactive/impulsive symptomatology during pre-adolescence.

Gender differences in prevalence, diagnosis and incidence of allergic and non-allergic asthma: a population-based cohort

BACKGROUND

Although women with severe non-allergic asthma may represent a substantial proportion of adults with asthma in clinical practice, gender differences in the incidence of allergic and non-allergic asthma have been little investigated in the general population.

METHODS

Gender differences in asthma prevalence, reported diagnosis and incidence were investigated in 9091 men and women randomly selected from the general population and followed up after 8-10 years as part of the European Community Respiratory Health Survey. The protocol included assessment of bronchial responsiveness, IgE specific to four common allergens and skin tests to nine allergens.

RESULTS

Asthma was 20% more frequent in women than in men over the age of 35 years. Possible under-diagnosis of asthma appeared to be particularly frequent among non-atopic individuals, but was as frequent in women as in men. The follow-up of subjects without asthma at baseline showed a higher incidence of asthma in women than in men (HR 1.94; 95% CI 1.40 to 2.68), which was not explained by differences in smoking, obesity or lung function. More than 60% of women and 30% of men with new-onset asthma were non-atopic. The incidence of non-allergic asthma was higher in women than in men throughout all the reproductive years (HR 3.51; 95% CI 2.21 to 5.58), whereas no gender difference was observed for the incidence of allergic asthma.

CONCLUSIONS

This study shows that female sex is an independent risk factor for non-allergic asthma, and stresses the need for more careful assessment of possible non-allergic asthma in clinical practice, in men and women.

Gender differences in prevalence, diagnosis and incidence of allergic and non-allergic asthma: a population-based cohort

BACKGROUND

Although women with severe non-allergic asthma may represent a substantial proportion of adults with asthma in clinical practice, gender differences in the incidence of allergic and non-allergic asthma have been little investigated in the general population.

METHODS

Gender differences in asthma prevalence, reported diagnosis and incidence were investigated in 9091 men and women randomly selected from the general population and followed up after 8-10 years as part of the European Community Respiratory Health Survey. The protocol included assessment of bronchial responsiveness, IgE specific to four common allergens and skin tests to nine allergens.

RESULTS

Asthma was 20% more frequent in women than in men over the age of 35 years. Possible under-diagnosis of asthma appeared to be particularly frequent among non-atopic individuals, but was as frequent in women as in men. The follow-up of subjects without asthma at baseline showed a higher incidence of asthma in women than in men (HR 1.94; 95% CI 1.40 to 2.68), which was not explained by differences in smoking, obesity or lung function. More than 60% of women and 30% of men with new-onset asthma were non-atopic. The incidence of non-allergic asthma was higher in women than in men throughout all the reproductive years (HR 3.51; 95% CI 2.21 to 5.58), whereas no gender difference was observed for the incidence of allergic asthma.

CONCLUSIONS

This study shows that female sex is an independent risk factor for non-allergic asthma, and stresses the need for more careful assessment of possible non-allergic asthma in clinical practice, in men and women.

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.

Exposure to second-hand smoke and reproductive outcomes depending on maternal asthma

Tobacco consumption and exposure to second-hand smoke (SHS) are associated with reduced birth weight. One issue that has not been clarified previously is that of the potential higher risk of this outcome in mothers with asthma. We assessed the role of prenatal maternal tobacco use and SHS on reproductive outcomes and assessed the interaction with maternal history of asthma. Data was collected from the INMA study, a maternal birth cohort selected from the general population established in Spain in 2002. We measured cotinine at the 32nd week of pregnancy in 2,219 females. Diagnosed maternal asthma was self-reported during pregnancy. 35% of mothers reported not being exposed to smoking or SHS during pregnancy. Active smoking (i.e. self-reported or cotinine >50 ng·mL(-1)) was related to a 134 g decrease in birth weight and a relative risk of 1.8 for small for gestational age and fetal growth restriction. These results were not modified by maternal asthma. Maternal asthma had a similar frequency in all exposure groups. Non SHS-exposed females had the lowest prevalence of asthma. SHS (i.e. cotinine 20-50 ng·mL(-1)) decreased birth weight by 32 g among those without maternal asthma, but these differences were not statistically significant (95% CI -88.76-24.76). Maternal asthma did not promote these effects. Maternal history of asthma did not modify the effects of smoking on reproductive outcomes in a cohort sampled from the general population.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Risk factors of new-onset asthma in adults: a population-based international cohort study

BACKGROUND

The occurrence of new-onset asthma during adulthood is common, but there is insufficient understanding of its determinants including the role of atopy.

OBJECTIVE

To assess the risk factors for the development of new-onset asthma in middle-aged adults and to compare them according to atopy.

METHODS

A longitudinal analysis of 9175 young adults who participated in two surveys of the European Community Respiratory Health Survey (ECRHS) conducted 9 years apart.

FINDINGS

We observed 179 cases of new-onset asthma among 4588 participants who were free of asthma and reported at the beginning of the follow-up that they had never had asthma (4.5 per 1000 person-years). In a logistic regression, the following risk factors were found to increase the risk of new-onset asthma: female gender (OR: 1.97; 95% confidence interval (CI): 1.38, 2.81), bronchial hyperresponsiveness (3.25; 2.19, 4.83), atopy (1.55; 1.08, 2.21), FEV(1) < 100 % predicted (1.87; 1.34, 2.62), nasal allergy (1.98;1.39,2.84) and maternal asthma (1.91; 1.13; 3.21). Obesity, respiratory infections in early life and high-risk occupations increased the risk of new-onset asthma although we had limited power to confirm their role. Among the atopics, total IgE and sensitization to cat were independently related to the risk of new-onset asthma. The proportion of new-onset asthma attributable to atopy varied from 12% to 21%.

CONCLUSION

Adults reporting that they had never had asthma were at a substantial risk of new-onset asthma as a result of multiple independent risk factors including lung function. Atopy explains a small proportion of new-onset adult asthma.

Prenatal exposure to traffic-related air pollution and ultrasound measures of fetal growth in the INMA Sabadell cohort

BACKGROUND

Few studies have used longitudinal ultrasound measurements to assess the effect of traffic-related air pollution on fetal growth.

OBJECTIVE

We examined the relationship between exposure to nitrogen dioxide (NO2) and aromatic hydrocarbons [benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene (BTEX)] on fetal growth assessed by 1,692 ultrasound measurements among 562 pregnant women from the Sabadell cohort of the Spanish INMA (Environment and Childhood) study.

METHODS

We used temporally adjusted land-use regression models to estimate exposures to NO2 and BTEX. We fitted mixed-effects models to estimate longitudinal growth curves for femur length (FL), head circumference (HC), abdominal circumference (AC), biparietal diameter (BPD), and estimated fetal weight (EFW). Unconditional and conditional SD scores were calculated at 12, 20, and 32 weeks of gestation. Sensitivity analyses were performed considering time-activity patterns during pregnancy.

RESULTS

Exposure to BTEX from early pregnancy was negatively associated with growth in BPD during weeks 20-32. None of the other fetal growth parameters were associated with exposure to air pollution during pregnancy. When considering only women who spent < 2 hr/day in nonresidential outdoor locations, effect estimates were stronger and statistically significant for the association between NO2 and growth in HC during weeks 12-20 and growth in AC, BPD, and EFW during weeks 20-32.

CONCLUSIONS

Our results lend some support to an effect of exposure to traffic-related air pollutants from early pregnancy on fetal growth during mid-pregnancy..

Ambient air pollution and the progression of atherosclerosis in adults

BACKGROUND

Cross-sectional studies suggest an association between exposure to ambient air pollution and atherosclerosis. We investigated the association between outdoor air quality and progression of subclinical atherosclerosis (common carotid artery intima-media thickness, CIMT).

METHODOLOGY/PRINCIPAL FINDINGS

We examined data from five double-blind randomized trials that assessed effects of various treatments on the change in CIMT. The trials were conducted in the Los Angeles area. Spatial models and land-use data were used to estimate the home outdoor mean concentration of particulate matter up to 2.5 micrometer in diameter (PM2.5), and to classify residence by proximity to traffic-related pollution (within 100 m of highways). PM2.5 and traffic proximity were positively associated with CIMT progression. Adjusted coefficients were larger than crude associations, not sensitive to modelling specifications, and statistically significant for highway proximity while of borderline significance for PM2.5 (P = 0.08). Annual CIMT progression among those living within 100 m of a highway was accelerated (5.5 micrometers/yr [95%CI: 0.13-10.79; p = 0.04]) or more than twice the population mean progression. For PM2.5, coefficients were positive as well, reaching statistical significance in the socially disadvantaged; in subjects reporting lipid lowering treatment at baseline; among participants receiving on-trial treatments; and among the pool of four out of the five trials.

CONCLUSION

Consistent with cross-sectional findings and animal studies, this is the first study to report an association between exposure to air pollution and the progression of atherosclerosis--indicated with CIMT change--in humans. Ostensibly, our results suggest that air pollution may contribute to the acceleration of cardiovascular disease development--the main causes of morbidity and mortality in many countries. However, the heterogeneity of the volunteering populations across the five trials, the limited sample size within trials and other relevant subgroups, and the fact that some key findings reached statistical significance in subgroups rather than the sample precludes generalizations to the general population.

Seafood consumption in pregnancy and infant size at birth: results from a prospective Spanish cohort

BACKGROUND

Studies on maternal seafood consumption during pregnancy and the risk of small for gestational age (SGA) births have yielded inconsistent results. As few studies have examined associations with specific seafood subtypes or accounted simultaneously for exposure to persistent organic pollutants (POPs), it is uncertain to what extent intakes of seafood subtypes with variable contaminant or fatty acid content may explain these inconsistencies.

METHODS

A cohort of 657 women recruited during the first trimester of pregnancy from a Mediterranean area with high seafood intakes was followed through birth. Dietary intakes were estimated using a validated questionnaire. Multivariable logistic regression was used to estimate associations between SGA and intakes of fatty fish, lean fish, canned tuna, crustaceans and other shellfish, adjusting for parity, child sex, parental anthropometry, socio-economic factors and serum levels of several POPs, including several polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB) and dichlorodiphenyldichloroethylene (DDE).

RESULTS

Overall, 7.8% of infants were SGA. Maternal consumption of crustaceans (more than once/week) and canned tuna (more than once/week was associated with a significantly increased risk of SGA. Fatty fish (more than once/week) was associated with weaker and generally non-significant increases in risk, while lean fish and other shellfish were not associated with SGA. Adjusting for contaminants did not meaningfully change results.

CONCLUSIONS

Higher maternal intakes of crustaceans and canned tuna, but not other types of seafood, were associated with increased risk of SGA independently of several POPs. Future studies exploring seafood subtypes and additional contaminants are needed to determine whether these associations are causal and identify mechanisms involved.

Association between GIS-based exposure to urban air pollution during pregnancy and birth weight in the INMA Sabadell Cohort

BACKGROUND

There is growing evidence that traffic-related air pollution reduces birth weight. Improving exposure assessment is a key issue to advance in this research area.

OBJECTIVE

We investigated the effect of prenatal exposure to traffic-related air pollution via geographic information system (GIS) models on birth weight in 570 newborns from the INMA (Environment and Childhood) Sabadell cohort.

METHODS

We estimated pregnancy and trimester-specific exposures to nitrogen dioxide and aromatic hydrocarbons [benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene (BTEX)] by using temporally adjusted land-use regression (LUR) models. We built models for NO(2) and BTEX using four and three 1-week measurement campaigns, respectively, at 57 locations. We assessed the relationship between prenatal air pollution exposure and birth weight with linear regression models. We performed sensitivity analyses considering time spent at home and time spent in nonresidential outdoor environments during pregnancy.

RESULTS

In the overall cohort, neither NO(2) nor BTEX exposure was significantly associated with birth weight in any of the exposure periods. When considering only women who spent < 2 hr/day in nonresidential outdoor environments, the estimated reductions in birth weight associated with an interquartile range increase in BTEX exposure levels were 77 g [95% confidence interval (CI), 7-146 g] and 102 g (95% CI, 28-176 g) for exposures during the whole pregnancy and the second trimester, respectively. The effects of NO(2) exposure were less clear in this subset.

CONCLUSIONS

The association of BTEX with reduced birth weight underscores the negative role of vehicle exhaust pollutants in reproductive health. Time-activity patterns during pregnancy complement GIS-based models in exposure assessment.

Traffic-related air pollution correlates with adult-onset asthma among never-smokers

BACKGROUND

Traffic-related pollution is associated with the onset of asthma in children. Its effect on adult-onset asthma is poorly investigated. The SAPALDIA cohort study was used to investigate associations between the 11-year change (1991-2002) in home outdoor traffic-related particulate matter up to 10 microm in diameter (TPM(10)) and the incidence of asthma.

METHODS

Never-smokers without asthma at baseline aged 18-60 years in 1991 were eligible for inclusion in the study. Subjects reporting doctor-diagnosed asthma at follow-up were considered incident cases. TPM(10) at baseline and follow-up was predicted and interpolated to subjects' place of residence by dispersion models using emission and meteorological data. Cox proportional hazard models for time to asthma onset were adjusted (age, gender, baseline atopy, body mass index, bronchial reactivity, maternal allergies).

RESULTS

Of 2725 never-smokers, 41 reported asthma onset in 2002. Home outdoor TPM(10) concentrations improved during the interval (mean -0.6; range -9 to +7.2; IQR 0.6 microg/m(3)). The incidence of asthma was associated with a change in TPM(10). The hazard ratio (1.30; 95% CI 1.05 to 1.61) per 1 microg/m(3) change in TPM(10) (IQR) was not sensitive to further adjustments (education, workplace exposure, passive smoking, parental asthma or allergies, random area effects, lung function or co-pollutants such as regional, secondary, total PM(10) or proximity to busy roads).

CONCLUSION

The data suggest a role for traffic-related pollution in adult-onset asthma. Space, time and source-specific individual assignment of exposure to traffic-related pollution is a key strength of SAPALDIA. It may explain why findings were statistically significant despite the limited number of new cases. As traffic-related pollution prevails, the finding may be of substantial public health relevance.

Air pollution and lung function in the European Community Respiratory Health Survey

BACKGROUND

The association of long-term air pollution and lung function has not been studied across adult European multi-national populations before. The aim of this study was to determine the association between long-term urban background air pollution and lung function levels, as well as change in lung function among European adults.

METHODS

Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and the ratio thereof (FEV1/FVC) were assessed at baseline and after 9 years of follow-up in adults from 21 European centres (followed-up sample 5610). Fine particles (PM(2.5)) were measured in 2000/2001 using central monitors.

RESULTS

Despite sufficient statistical power no significant associations were found between city-specific annual mean PM(2.5) and average lung function levels. The findings also do not support an effect on change in lung function, albeit statistical power was insufficient to significantly detect such an association.

CONCLUSIONS

The inability to refuse the null hypothesis may reflect (i) no effect of urban air pollution on lung function or (ii) inherent biases due to the study design. Examples of the latter are lack of individual-level air quality assignment, not quantified within-city contrasts in traffic-related pollution, or the heterogeneity of the studied populations and their urban environments. Future studies on long-term effects of air pollution on lung function could increase statistical power and reduce potential misclassification and confounding by characterizing exposure on the level of individuals, capturing contrasts due to local sources, in particular traffic.

The effect of supplementation with omega-3 polyunsaturated fatty acids on markers of oxidative stress in elderly exposed to PM(2.5)

BACKGROUND

The mechanisms of particulate matter (PM)-induced health effects are believed to involve inflammation and oxidative stress. Increased intake of omega-3 polyunsaturated fatty acids (n-3 PUFA) appears to have anti-inflammatory effects.

OBJECTIVE

As part of a trial to evaluate whether n-3 PUFA supplementation could protect against the cardiac alterations linked to PM exposure, we measured biomarkers of response to oxidative stimuli [copper/zinc (Cu/Zn) superoxide dismutase (SOD) activity, lipoperoxidation (LPO) products, and reduced glutathione (GSH)] and evaluated the impact of supplementation on plasma levels.

METHODS

We recruited residents from a nursing home in Mexico City chronically exposed to PM < or = 2.5 microm in aerodynamic diameter (PM(2.5)) and followed them from 26 September 2001 to 10 April 2002. We randomly assigned subjects in a double-blind fashion to receive either fish oil (n-3 PUFA) or soy oil. We measured PM(2.5) levels indoors at the nursing home, and measured Cu/Zn SOD activity, LPO products, and GSH at different times during presupplementation and supplementation phases.

RESULTS

Supplementation with either fish or soy oil was related to an increase of Cu/Zn SOD activity and an increase in GSH plasma levels, whereas exposure to indoor PM(2.5) levels was related to a decrease in Cu/Zn SOD activity and GSH plasma levels.

CONCLUSION

Supplementation with n-3 PUFA appeared to modulate the adverse effects of PM(2.5) on these biomarkers, particularly in the fish oil group. Supplementation with n-3 PUFA could modulate oxidative response to PM(2.5) exposure.

Thyroid disruption at birth due to prenatal exposure to beta-hexachlorocyclohexane

OBJECTIVE

Thyroid hormones play an important role in human brain development, and some organochlorine compounds (OCs) act as thyroid disruptors. The objective of the present study was to evaluate the association between prenatal exposure to organochlorine compounds and thyroid function in newborns from a general population birth cohort in Menorca, with an a-priori specific focus on beta-HCH.

METHODS

Levels of polychlorinated biphenyls (PCB congeners 28, 52, 101, 118, 138, 153 and 180), hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), dichlorodiphenyl dichloroethylene (p'p'-DDE) and dichlorodiphenyl trichloroethane (p'p-DDT) in cord serum, and thyrotropin (TSH) concentration in plasma three days after birth were measured in 387 newborns from Menorca. The TSH concentration was categorized (high or low), except for 27 children whose TSH levels were quantified.

RESULTS

Levels of beta-HCH and PCB-153 were positively related to TSH concentrations (gestational age-adjusted coefficient (p-value): 0.26 (p = 0.006) and 0.31 (p = 0.050), respectively).

CONCLUSIONS

beta-HCH is potentially a new thyroid disrupting compound, deserving special interest in future studies given its high body burden in humans.

Mediterranean diet in pregnancy is protective for wheeze and atopy in childhood

INTRODUCTION

Dietary intake of specific nutrients or food groups during pregnancy could play a role in the risk of asthma and atopy in offspring, but specific dietary patterns have not been implicated. The authors evaluated the impact of maternal (during pregnancy) and child adherence to a Mediterranean diet on asthma and atopy in childhood.

METHODS

Women presenting for antenatal care at all general practices in Menorca, a Mediterranean island in Spain, over a 12 month period starting in mid-1997 were recruited. 460 children were included in the analysis after 6.5 years of follow-up. Maternal dietary intake during pregnancy and children's dietary intake at age 6.5 years were assessed by food frequency questionnaires, and adherence to a Mediterranean diet was evaluated by a priori defined scores. During follow-up, parents completed questionnaires on the child's respiratory and allergic symptoms. Children underwent skin prick tests with six common aeroallergens.

RESULTS

The prevalence rates of persistent wheeze, atopic wheeze and atopy at age 6.5 years were 13.2%, 5.8% and 17.0%, respectively. One-third (36.1%) of mothers had a low quality Mediterranean diet during pregnancy according to the Mediterranean Diet Score, while the rest had a high score. A high Mediterranean Diet Score during pregnancy (at two levels, using "low" score as the reference) was found to be protective for persistent wheeze (OR 0.22; 95% CI 0.08 to 0.58), atopic wheeze (OR 0.30; 95% CI 0.10 to 0.90) and atopy (OR 0.55; 95% CI 0.31 to 0.97) at age 6.5 years after adjusting for potential confounders. Childhood adherence to a Mediterranean diet was negatively associated with persistent wheeze and atopy although the associations did not reach statistical significance.

CONCLUSION

These results support a protective effect of a high level of adherence to a Mediterranean diet during pregnancy against asthma-like symptoms and atopy in childhood.