Plasma polyamines during pregnancy and their relationships with maternal allergies and the immune response of the neonates.

BACKGROUND: Some studies have reported that polyamine levels may influence immune system programming. The aim of this study was to evaluate the polyamine profile during gestation and its associations with maternal allergy and cytokine production in cord blood cells in response to different allergenic stimuli. METHODS: Polyamines were determined in plasma of pregnant women (24 weeks, N = 674) and in umbilical cord samples (N = 353 vein and N = 160 artery) from the Mediterranean NELA birth cohort. Immune cell populations were quantified, and the production of cytokines in response to different allergic and mitogenic stimuli was assessed in cord blood. RESULTS: Spermidine and spermine were the most prevalent polyamines in maternal, cord venous, and cord arterial plasma. Maternal allergies, especially allergic conjunctivitis, were associated with lower spermine in umbilical cord vein. Higher levels of polyamines were associated with higher lymphocyte number but lower Th2-related cells in cord venous blood. Those subjects with higher levels of circulating polyamines in cord showed lower production of inflammatory cytokines, especially IFN-α, and lower production of Th2-related cytokines, mainly IL-4 and IL-5. The effects of polyamines on Th1-related cytokines production were uncertain. CONCLUSIONS: Spermidine and spermine are the predominant polyamines in plasma of pregnant women at mid-pregnancy and also in umbilical cord. Maternal allergic diseases like allergic conjunctivitis are related to lower levels of polyamines in cord vein, which could influence the immune response of the newborn. Cord polyamine content is related to a decreased Th2 response and inflammatory cytokines production, which might be important to reduce an allergenic phenotype in the neonate.

Urinary concentrations of non-essential and essential elements during weaning in infants from the NELA cohort in Spain.

Infancy is a period of continuous growth and development, where inadequate intake of essential elements and exposure to non-essential elements may have lifelong health consequences. Thus, the aim of this study is to evaluate the urine concentration of essential and non-essential elements as a proxy for internal exposure during the weaning period, from 3 to 18 months of age. The Nutrition in Early Life and Asthma (NELA) birth cohort generated the data for this study. Sociodemographic, dietary, and urine concentration of essential (Co, Cu, Mo, I, Fe, Mn, Se, Zn, and Ni) and non-essential elements (Al, V, As, Cd, Sb, Tl, and Pb) data were available for 490 participants at 3 months of age and 216 participants at 18 months of age. Paired urine samples at both time periods were available for 175 infants. At 3 months of age, exclusively breastfed infants had lower urine concentrations of Al, V, Fe, Co, Se, Sb, and Tl. Notably, the concentration of Mo had a median (IQR) of 0.60 (0.40-2.10) µg/L compared to a median (IQR) of 39.80 (25.00-56.40) µg/L observed in infants exclusively fed with formula. When we analyzed the change in urine elements concentrations between 3 and 18 months of age, we observed increased As (0.75 vs. 18.60 µg/L), Co (0.05 vs. 0.24 µg/L), Mo (1.98 vs. 50.0 µg/L), Pb (0.15 vs. 0.69 µg/L), Se (11.3 vs. 23.1 µg/L), Tl (0.02 vs. 0.11 µg/L), and V (0.05 vs. 0.11 µg/L). For Cu, lower urine concentrations were observed at 18 months of age in comparison with concentrations at 3 months (5.77 vs. 4.41 µg/L). Among the main food items identified as driving the changes in urine concentration between 3 and 18 months of age were white fish, rice and pasta, potato chips, custard, small blue fish, and legumes. Exclusively breastfed infants showed lower exposure to non-essential elements compared to those who were fed with a mixture or formula. With the introduction of solid foods, the exposure to some non-essential elements increased drastically, as in the case of As and Pb. In addition, exposure to the essential metal Mo also increased substantially with the introduction of solid food.

Cytokine production by newborns: influence of sex and season of birth.

BACKGROUND: Immune signatures at birth could be associated with clinical outcomes and will improve our understanding of immunity prenatal programming. METHODS: Data come from 235 newborns from the cohort study NELA. Production of cytokines was determined using Luminex technology. Associations between cytokine concentrations with sex and season of birth were examined by multivariate regression models. RESULTS: Umbilical cord blood cells produced high levels of inflammatory cytokines, moderate levels of Th1/Th2/Tr-related cytokines, and low levels of Th17 cytokines. Compared to females, male newborn cells secreted higher levels of Th2 (peptidoglycan-stimulated IL-13, odds ratio [OR] = 2.26; 95% CI 1.18, 4.31, p value = 0.013) and Th17 (polyinosinic:polycytidylic acid-stimulated IL-23, OR = 1.82, 95% CI 1.01, 3.27, p value = 0.046) and lower levels of Th1 (olive-stimulated IL-2, OR = 0.56, 95% CI 0.31, 0.99, p value = 0.047) cytokines. Also, children born during warm seasons showed decreased innate cytokine response to peptidoglycan (IL-6, OR = 0.28, 95% CI 0.15, 0.52, p value < 0.001) compared to those born in cold seasons; meanwhile, adaptive immunity cytokines were more frequently secreted by children born during warm seasons in response to allergen extracts (IL-10, OR = 2.11, 95% CI 1.12, 3.96, p value = 0.020; IL-17F, OR = 3.31, 95% CI 1.83, 5.99, p value < 0.001). CONCLUSION: Newborns showed specific cytokines signatures influenced by sex and season of birth. IMPACT: There is a limited number of population-based studies on the immune status at birth and the influence of prenatal and perinatal factors on it. Characterization of cytokine signatures at birth related to the prenatal environment could improve our understanding of immunity prenatal programming. Newborns exhibit specific unstimulated and stimulated cytokine signatures influenced by sex and season of birth. Unstimulated and stimulated cytokine signatures in newborns may be associated with the development of related clinical outcomes later in life.

Serum Vitamins A and E at Mid-Pregnancy and Their Relationships with Both Maternal and Cord Blood Antioxidant Status and Perinatal Conditions: The NELA Cohort.

INTRODUCTION: Most of the pregnant women do not achieve the recommended dietary intake of vitamins A and E. These vitamins may counteract oxidative stress involved in some adverse perinatal outcomes. We aimed to assess the associations between maternal vitamin A and E at mid-pregnancy with both maternal and fetal outcomes and to identify possible early biomarkers during pregnancy to predict and prevent oxidative stress in the offspring. METHODS: Data on dietary and serum levels of vitamins A and E were collected from 544 pregnant women from the Nutrition in Early Life and Asthma (NELA) study, a prospective mother-child cohort set up in Spain. RESULTS: There were large discrepancies between low dietary vitamin E intake (78% of the mothers) and low serum vitamin E levels (3%) at 24 weeks of gestation. Maternal serum vitamins A and E at mid-pregnancy were associated with higher antioxidant status not only in the mother at this time point (lower hydroperoxides and higher total antioxidant activity [TAA]) but also with the newborn at birth (higher TAA). Gestational diabetes mellitus (GDM) was negatively associated with maternal serum vitamin A (OR: 0.95 CI: 0.91-0.99, p = 0.009) at mid-pregnancy. Nevertheless, we could not detect any association between GDM and oxidative stress parameters. CONCLUSIONS: In conclusion, maternal vitamin A and E serum levels may be used as an early potential biomarker of antioxidant status of the neonate at birth. Control of these vitamins during pregnancy could help avoid morbid conditions in the newborn caused by oxidative stress in GDM pregnancies.

Worldwide trends in the burden of asthma symptoms in school-aged children: Global Asthma Network Phase I cross-sectional study.

BACKGROUND: Asthma is the most common chronic disease in children globally. The Global Asthma Network (GAN) Phase I study aimed to determine if the worldwide burden of asthma symptoms is changing. METHODS: This updated cross-sectional study used the same methods as the International study of Asthma and Allergies in Childhood (ISAAC) Phase III. Asthma symptoms were assessed from centres that completed GAN Phase I and ISAAC Phase I (1993-95), ISAAC Phase III (2001-03), or both. We included individuals from two age groups (children aged 6-7 years and adolescents aged 13-14 years) who self-completed written questionnaires at school. We estimated the 10-year rate of change in prevalence of current wheeze, severe asthma symptoms, ever having asthma, exercise wheeze, and night cough (defined by core questions in the questionnaire) for each centre, and we estimated trends across world regions and income levels using mixed-effects linear regression models with region and country income level as confounders. FINDINGS: Overall, 119 795 participants from 27 centres in 14 countries were included: 74 361 adolescents (response rate 90%) and 45 434 children (response rate 79%). About one in ten individuals of both age groups had wheeze in the preceding year, of whom almost half had severe symptoms. Most centres showed a change in prevalence of 2 SE or more between ISAAC Phase III to GAN Phase I. Over the 27-year period (1993-2020), adolescents showed a significant decrease in percentage point prevalence per decade in severe asthma symptoms (-0·37, 95% CI -0·69 to -0·04) and an increase in ever having asthma (1·25, 0·67 to 1·83) and night cough (4·25, 3·06 to 5·44), which was also found in children (3·21, 1·80 to 4·62). The prevalence of current wheeze decreased in low-income countries (-1·37, -2·47 to -0·27], in children and -1·67, -2·70 to -0·64, in adolescents) and increased in lower-middle-income countries (1·99, 0·33 to 3·66, in children and 1·69, 0·13 to 3·25, in adolescents), but it was stable in upper-middle-income and high-income countries. INTERPRETATION: Trends in prevalence and severity of asthma symptoms over the past three decades varied by age group, country income, region, and centre. The high worldwide burden of severe asthma symptoms would be mitigated by enabling access to effective therapies for asthma. FUNDING: International Union Against Tuberculosis and Lung Disease, Boehringer Ingelheim New Zealand, AstraZeneca Educational Grant, National Institute for Health Research, UK Medical Research Council, European Research Council, and Instituto de Salud Carlos III.

The burden of asthma, hay fever and eczema in children in 25 countries: GAN Phase I study.

AIMS: There have been no worldwide standardised surveys of prevalence and severity of asthma, rhinoconjunctivitis and eczema in school children for 15 years. The present study aims to provide this information. METHODS: Following the exact International Study of Asthma and Allergies in Childhood (ISAAC) methodology (cross-sectional questionnaire-based survey), Global Asthma Network (GAN) Phase I was carried out between 2015 and 2020 in many centres worldwide. RESULTS: The study included 157 784 adolescents (13-14 years of age) in 63 centres in 25 countries and 101 777 children (6-7 years of age) in 44 centres in 16 countries. The current prevalence of symptoms, respectively, was 11.0% and 9.1% for asthma, 13.3% and 7.7% for rhinoconjunctivitis and 6.4% and 5.9% for eczema. The prevalence of asthma ever was 10.5% and 7.6%, hay fever ever was 15.2% and 11.1% and eczema ever was 10.6% and 13.4%, respectively. Centres in low or lower middle gross national income countries (LICs or LMICs) had significantly lower prevalence of the three disease symptoms and diagnoses (except for hay fever). In children, the prevalence of asthma and rhinoconjunctivitis symptoms was higher in boys, while the reverse occurred among adolescents. For eczema, while the prevalence among female adolescents was double that of males, there was no sex difference among children. Centre accounted for non-negligible variability in all disease symptoms (10-20%). CONCLUSION: The burdens of asthma, rhinoconjunctivitis and eczema vary widely among the limited number of countries studied. Although symptom prevalence is lower in LICs and LMICs, it represents a considerable burden everywhere studied.

The burden of asthma, hay fever and eczema in adults in 17 countries: GAN Phase I study.

AIMS: Asthma, hay fever and eczema are three common chronic conditions. There have been no recent multi-country data on the burden of these three conditions in adults; the aims of this study are to fill this evidence gap. METHODS: The Global Asthma Network Phase I is a multi-country cross-sectional population-based study using the same core methodology as the International Study of Asthma and Allergies in Childhood Phase III. It provides data on the burden of asthma, hay fever and eczema in children and adolescents, and, for the first time, in their parents/guardians. RESULTS: Data were available from 193 912 adults (104 061 female; mean±sd age 38±7.5 years) in 43 centres in 17 countries. The overall prevalence (range) of symptoms was 6.6% (0.9-32.7%) for current wheeze, 4.4% (0.9-29.0%) for asthma ever, 14.4% (2.8-45.7%) for hay fever ever and 9.9% (1.6-29.5%) for eczema ever. Centre prevalence varied considerably both between countries and within countries. There was a moderate correlation between hay fever ever and asthma ever, and between eczema ever and hay fever ever at the centre level. There were moderate to strong correlations between indicators of the burden of disease reported in adults and the two younger age groups. CONCLUSION: We found evidence for a substantial burden of asthma, hay fever ever and eczema ever in the countries examined, highlighting the major public health importance of these diseases. Prevention strategies and equitable access to effective and affordable treatments for these three conditions would help mitigate the avoidable morbidity they cause.

Worldwide time trends in prevalence of symptoms of rhinoconjunctivitis in children: Global Asthma Network Phase I.

BACKGROUND: The Global Asthma Network (GAN), by using the International Study of Asthma and Allergies in Childhood (ISAAC) methodology, has updated trends in prevalence of symptoms of childhood allergic diseases, including non-infective rhinitis and conjunctivitis ('rhinoconjunctivitis'), which is reported here. METHODS: Prevalence and severity of rhinoconjunctivitis were assessed by questionnaire among schoolchildren in GAN Phase I and ISAAC Phase I and III surveys 15-23 years apart. Absolute rates of change in prevalence were estimated for each centre and modelled by multi-level linear regression to compare trends by age group, time period and per capita national income. RESULTS: Twenty-seven GAN centres in 14 countries surveyed 74,361 13- to 14-year-olds ('adolescents') and 45,434 6- to 7-year-olds ('children'), with average response proportions of 90% and 79%, respectively. Many centres showed highly significant (p < .001) changes in prevalence of rhinoconjunctivitis in the past year ('current rhinoconjunctivitis') compared with ISAAC. The direction and magnitude of centre-level trends varied significantly (p < .001) both within and between countries. Overall, current rhinoconjunctivitis prevalence decreased slightly from ISAAC Phase III to GAN: -1.32% per 10 years, 95% CI [-2.93%, +0.30%] among adolescents; and -0.44% [-1.29%, +0.42%] among children. Together, these differed significantly (p < .001) from the upward trend within ISAAC. Among adolescents, centre-level trends in current rhinoconjunctivitis were highly correlated with those for eczema symptoms (rho = 0.72, p < .0001) but not with centre-level trends in asthma symptoms (rho = 0.15, p = .48). Among children, these correlations were positive but not significant. CONCLUSION: Symptoms of non-infective rhinoconjunctivitis among schoolchildren may no longer be on the increase globally, although trends vary substantially within and between countries.

Cytokine profiles in cord blood in relation to prenatal traffic-related air pollution: The NELA cohort.

BACKGROUND: Outdoor air pollution may disturb immune system development. We investigated whether gestational exposure to traffic-related air pollutants (TRAP) is associated with unstimulated cytokine profiles in newborns. METHODS: Data come from 235 newborns of the NELA cohort. Innate response-related cytokines (IL-6, IFN-α, IL1-ß, and TNF-α), Th1-related (IFN-γ and IL-2), Th2-related (IL-4, IL-5, and IL-13), Th17-related (IL-17 and IL-23), and immunomodulatory cytokine IL-10 were quantified in the supernatant of unstimulated whole umbilical cord blood cells after 7 days of culture using the Luminex technology. Dispersion/chemical transport modeling was used to estimate long-term (whole pregnancy and trimesters) and short-term (15 days before delivery) residential exposures to traffic-related nitrogen dioxide (NO2 ), particulate matter (PM2.5 and PM10 ), and ozone (O3 ). We fitted multivariable logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression models. RESULTS: NO2 during the whole pregnancy increased the odds of detection of IL-1ß (OR per 10 µg/m3 increase = 1.37; 95% CI, 1.02, 1.85) and IL-6 (OR per 10 µg/m3 increase = 1.32; 95% CI 1.00, 1.75). Increased odds of detected concentrations of IL-10 was found in newborns exposed during whole pregnancy to higher levels of NO2 (OR per 10 µg/m3 increase = 1.30; 95% CI 0.99, 1.69), PM10 (OR per 10 µg/m3 increase = 1.49; 95% CI 0.95, 2.33), and PM2.5 (OR per 5 µg/m3 increase = 1.56; 95% CI 0.97, 2.51). Exposure to O3 during the whole pregnancy increased the odds of detected IL-13 (OR per 10 µg/m3 increase = 1.22; 95% CI 1.01, 1.49). WQS model revealed first and third trimesters of gestation as windows of higher susceptibility. CONCLUSIONS: Gestational exposure to TRAP may increase detection of pro-inflammatory, Th2-related, and T regulatory cytokines in newborns. These changes might influence immune system responses later in life.

The Nutrition in Early Life and Asthma (NELA) birth cohort study: Rationale, design, and methods.

BACKGROUND: Primary prevention strategies for asthma are lacking. Its inception probably starts in utero and/or during the early postnatal period as the developmental origins of health and disease (DOHaD) paradigm suggests. OBJECTIVES: The main objective of Nutrition in Early Life and Asthma (NELA) cohort study is to unravel whether the following factors contribute causally to the developmental origins of asthma: (1) maternal obesity/adiposity and foetal growth; (2) maternal and child nutrition; (3) outdoor air pollution; (4) endocrine disruptors; and (5) maternal psychological stress. Maternal and offspring biological samples are used to assess changes in offspring microbiome, immune system, epigenome and volatilome as potential mechanisms influencing disease susceptibility. POPULATION: Randomly selected pregnant women from three health areas of Murcia, a south-eastern Mediterranean region of Spain, who fulfilled the inclusion criteria were invited to participate at the time of the follow-up visit for routine foetal anatomy scan at 19-22 weeks of gestation, at the Maternal-Fetal Medicine Unit of the "Virgen de la Arrixaca" University Clinical Hospital over a 36-month period, from March 2015 to April 2018. DESIGN: Prospective, population-based, maternal-child, birth cohort study. METHODS: Questionnaires on exposures and outcome variables were administered to mothers at 20-24 gestation week; 32-36 gestation week; and delivery. Children were surveyed at birth, 3 and 18 months of age and currently at 5 years. Furthermore, physical examinations were performed; and different measurements and biological samples were obtained at these time points. PRELIMINARY RESULTS: Among the 1350 women invited to participate, 738 (54%) were finally enrolled in the study and 720 of their children were eligible at birth. The adherence was high with 612 children (83%) attending the 3 months' visit and 532 children (72%) attending the 18 months' visit. CONCLUSION: The NELA cohort will add original and unique knowledge to the developmental origins of asthma.

Neurodevelopmental effects of prenatal vitamin D in humans: systematic review and meta-analysis.

Diverse studies have investigated the impact of prenatal exposure to vitamin D levels on brain development; however, evidence in humans has never been systematically reviewed. This article summarized evidence of the association between 25-hydroxyvitamin D [25(OH)D] levels in maternal blood in pregnancy or newborn blood at birth and neurodevelopmental outcomes, including cognition, psychomotor performance, language development, behavioral difficulties, attention deficit and hyperactivity disorder (ADHD), and autistic traits. PubMed, Web of Science and SCOPUS databases were systematically searched for epidemiologic studies published through May 2018 using keywords. Random-effects meta-analyses were conducted. Of 260 identified articles, 25 were included in the present review. Comparing the highest vs. the lowest category of prenatal 25(OH)D levels, the pooled beta coefficients were 0.95 (95% CI -0.03, 1.93; p = 0.05) for cognition, and 0.88 (95% CI -0.18, 1.93; p = 0.10) for psychomotor development. The pooled relative risk for ADHD was 0.72 (95% CI, 0.59, 0.89; p = 0.002), and the pooled odds ratio for autism-related traits was 0.42 (95% CI, 0.25, 0.71; p = 0.001). There was little evidence for protective effects of high prenatal 25(OH)D for language development and behavior difficulties. This meta-analysis provides supporting evidence that increased prenatal exposure to 25(OH)D levels is associated with improved cognitive development and reduced risk of ADHD and autism-related traits later in life. Associations represent a potentially high public health burden given the current prevalence of vitamin D deficiency and insufficiency among childbearing aging and pregnant women.

Air pollution from traffic during pregnancy impairs newborn's cord blood immune cells: The NELA cohort.

BACKGROUND: Hazards of traffic-related air pollution (TRAP) on the developing immune system are poorly understood. We sought to investigate the effects of prenatal exposure to TRAP on cord blood immune cell distributions; and to identify gestational windows of susceptibility. METHODS: In-depth immunophenotyping of cord blood leukocyte and lymphocyte subsets was performed by flow cytometry in 190 newborns embedded in the Nutrition in Early Life and Asthma (NELA) birth cohort (2015-2018). Long-term (whole pregnancy and trimesters) and short-term (15-days before delivery) residential exposures to traffic-related nitrogen dioxide (NO2), particulate matter (PM2.5 and PM10), and ozone (O3) were estimated using dispersion/chemical transport modelling. Associations between TRAP concentrations and cord blood immune cell counts were assessed using multivariate Poisson regression models. RESULTS: Mean number of natural killer (NK) cells decreased 15% in relation to higher NO2 concentrations (≥36.4 µg/m3) during whole pregnancy (incidence relative risk (IRR), 0.85; 95% CI, 0.72, 0.99), with stronger associations in the first trimester. Higher PM2.5 concentrations (≥13.3 µg/m3) during whole pregnancy associated with a reduced mean number of cytotoxic T cells (IRR, 0.88; 95% CI, 0.78, 0.99). Newborns exposed to higher PM10 (≥23.6 µg/m3) and PM2.5 concentrations during the first and third trimester showed greater mean number of helper T type 1 (Th1) cells (P < 0.05). Decreased number of regulatory T (Treg) cells was associated with greater short-term NO2 (IRR, 0.90; 95% CI, 0.80, 1.01) and PM10 (IRR, 0.88; 95% CI, 0.77, 0.99) concentrations. CONCLUSIONS: Prenatal exposure to TRAP, particularly in early and late gestation, impairs fetal immune system development through disturbances in cord blood leukocyte and lymphocyte distributions.

Influence of KRAS mutations, persistent organic pollutants, and trace elements on survival from pancreatic ductal adenocarcinoma.

INTRODUCTION: Reasons why pancreatic ductal adenocarcinoma (PDAC) continues to have poor survival are only partly known. No previous studies have analyzed the combined influence of KRAS mutations, persistent organic pollutants (POPs), and trace elements upon survival in PDAC or in any other human cancer. OBJECTIVE: To analyze the individual and combined influence of KRAS mutations, POPs, and trace elements upon survival from PDAC. METHODS: Incident cases of PDAC (n = 185) were prospectively identified in five hospitals in Eastern Spain in 1992-1995 and interviewed face-to-face during hospital admission. KRAS mutational status was determined from tumour tissue through polymerase chain reaction and artificial restriction fragment length polymorphism. Blood and toenail samples were obtained before treatment. Serum concentrations of POPs were analyzed by high-resolution gas chromatography with electron-capture detection. Concentrations of 12 trace elements were determined in toenail samples by inductively coupled plasma mass spectrometry. Multivariable Cox proportional hazards regression was used to assess prognostic associations. RESULTS: Patients with a KRAS mutated tumor had a 70% higher risk of early death than patients with a KRAS wild-type PDAC (hazard ratio [HR] = 1.7, p = 0.026), adjusting for age, sex, and tumor stage. KRAS mutational status was only modestly and not statistically significantly associated with survival when further adjusting by treatment or by treatment intention. The beneficial effects of treatment remained unaltered when KRAS mutational status was taken into account, and treatment did not appear to be less effective in the subgroup of patients with a KRAS mutated tumor. POPs did not materially influence survival: the adjusted HR of the highest POP tertiles was near unity for all POPs. When considering the joint effect on survival of POPs and KRAS, patients with KRAS mutated tumors had modest and nonsignificant HRs (most HRs around 1.3 to 1.4). Higher concentrations of lead, cadmium, arsenic, vanadium, and aluminium were associated with better survival. When KRAS status, POPs, and trace elements were simultaneously considered along with treatment, only the latter was statistically significantly related to survival. CONCLUSIONS: In this study based on molecular, clinical, and environmental epidemiology, KRAS mutational status, POPs, and trace elements were not adversely related to PDAC survival when treatment was simultaneously considered; only treatment was independently related to survival. The lack of adverse prognostic effects of POPs and metals measured at the time of diagnosis provide scientific and clinical reassurance on the effects of such exposures upon survival of patients with PDAC. The weak association with KRAS mutations contributes to the scant knowledge on the clinical implications of a genetic alteration highly frequent in PDAC.

Combined impact of healthy lifestyle factors on risk of asthma, rhinoconjunctivitis and eczema in school children: ISAAC phase III.

BACKGROUND: Asthma is not the key focus of prevention strategies. A Healthy Lifestyle Index (HLI) was developed to examine the combined effect of modifiable lifestyle factors on asthma, rhinoconjunctivitis and eczema using data from the International Study of Asthma and Allergies in Childhood (ISAAC) phase III. METHODS: Information on symptoms of asthma, rhinoconjunctivitis, eczema and several lifestyle factors was obtained from children aged 6-7 years through written questionnaires. The HLI combined five lifestyle factors: no parental smoking, child's adherence to Mediterranean diet, child's healthy body mass index, high physical activity and non-sedentary behaviour. The association between the HLI and risk of asthma, rhinoconjunctivitis and eczema was evaluated using multilevel mixed-effects logistic regression models. FINDINGS: Data of 70 795 children from 37 centres in 19 countries were analysed. Each additional healthy lifestyle factor was associated with a reduced risk of current wheeze (OR 0.87, 95% CI 0.84 to 0.89), asthma ever (OR 0.89, 95% CI 0.87 to 0.92), current symptoms of rhinoconjunctivitis (OR 0.95, 95% CI 0.92 to 0.97) and current symptoms of eczema (OR 0.92, 95% CI 0.92 to 0.98). Theoretically, if associations were causal, a combination of four or five healthy lifestyle factors would result into a reduction up to 16% of asthma cases (ranging from 2.7% to 26.3 % according to region of the world). CONCLUSIONS: These findings should be interpreted with caution given the limitations to infer causality from cross-sectional observational data. Efficacy of interventions to improve multiple modifiable lifestyle factors to reduce the burden asthma and allergy in childhood should be assessed.

Prenatal vitamin D status and respiratory and allergic outcomes in childhood: A meta-analysis of observational studies.

BACKGROUND: Prenatal vitamin D status may influence offspring's respiratory and allergic outcomes; however, evidence is inconclusive. A systematic review and meta-analysis were conducted on the association between 25-hydroxyvitamin D [25(OH)D] levels in maternal blood in pregnancy or cord blood at birth with the risk of offspring's respiratory and allergic conditions. METHODS: Two independent researchers conducted systematic searches for observational studies published until May 2017 using defined keywords on vitamin D and health outcomes, including respiratory tract infections (RTIs), wheeze, asthma, atopic eczema, allergic rhinitis, allergic sensitization, and lung function. Random-effects meta-analyses were conducted. RESULTS: A total of 34 from 547 retrieved articles were included. Increased prenatal exposure to 25(OH)D was inversely associated with risk of RTIs. Comparing the highest with the lowest category of 25(OH)D levels, the pooled odds ratio was 0.64 (95% CI 0.47, 0.87). A positive borderline association was found for lung function at school age (FEV1 z-score coefficient 0.07, 95% CI -0.01, 0.15). No associations were found for wheeze, asthma, atopic eczema, allergic rhinitis, and allergic sensitization. CONCLUSION: The introduction of public health measures to tackle vitamin D status in pregnancy may reduce the burden of RTIs in offspring. Current evidence does not support an impact on asthma and allergy.

Maternal and Foetal Health Implications of Vitamin D Status during Pregnancy.

BACKGROUND: To what extent does the circulating 25-hydroxyvitamin D (25[OH]D) concentration help to meet the physiological needs of humans is an ongoing subject of debate. Remaining unexposed to the sun to reduce melanoma cancer risk, current lifestyle with less out door activities, and increasing obesity rates, which in turn increases the storage of vitamin D in the adipose tissue, are presumably factors that contribute to the substantial upsurge in the prevalence of vitamin D deficiency in humans. Since evidence is lacking regarding the appropriate cut-off points to define vitamin D status during pregnancy, references used to establish the intake recommendations and vitamin D content of prenatal vitamin supplements are quite conservative. SUMMARY: The foetus depends fully on maternal 25(OH)D supply. 25(OH)D readily crosses the placenta and it is activated into 1,25(OH)2D by foetal kidneys. Moreover, 1,25(OH)2D can also be synthesized within the placenta to regulate placental metabolism. The importance of vitamin D during pregnancy for maintaining maternal calcium homeostasis and therefore for foetal bone development is well recognized; major discussions are in progress regarding the potential maternal detrimental effects on pregnancy outcomes, foetal development, and the long-term health of children. Interventional studies have also evaluated the effect of vitamin D for reduction on preterm birth and asthma programming. Key Messages: Clinically, by understanding the effects of vitamin D on perinatal outcomes, we could individualize antenatal counselling regarding vitamin D supplementation to ensure vitamin D repletion without increasing the risk of foetal hypercalcemia.

Early growth characteristics and the risk of reduced lung function and asthma: A meta-analysis of 25,000 children.

BACKGROUND: Children born preterm or with a small size for gestational age are at increased risk for childhood asthma. OBJECTIVE: We sought to assess the hypothesis that these associations are explained by reduced airway patency. METHODS: We used individual participant data of 24,938 children from 24 birth cohorts to examine and meta-analyze the associations of gestational age, size for gestational age, and infant weight gain with childhood lung function and asthma (age range, 3.9-19.1 years). Second, we explored whether these lung function outcomes mediated the associations of early growth characteristics with childhood asthma. RESULTS: Children born with a younger gestational age had a lower FEV1, FEV1/forced vital capacity (FVC) ratio, and forced expiratory volume after exhaling 75% of vital capacity (FEF75), whereas those born with a smaller size for gestational age at birth had a lower FEV1 but higher FEV1/FVC ratio (P < .05). Greater infant weight gain was associated with higher FEV1 but lower FEV1/FVC ratio and FEF75 in childhood (P < .05). All associations were present across the full range and independent of other early-life growth characteristics. Preterm birth, low birth weight, and greater infant weight gain were associated with an increased risk of childhood asthma (pooled odds ratio, 1.34 [95% CI, 1.15-1.57], 1.32 [95% CI, 1.07-1.62], and 1.27 [95% CI, 1.21-1.34], respectively). Mediation analyses suggested that FEV1, FEV1/FVC ratio, and FEF75 might explain 7% (95% CI, 2% to 10%) to 45% (95% CI, 15% to 81%) of the associations between early growth characteristics and asthma. CONCLUSIONS: Younger gestational age, smaller size for gestational age, and greater infant weight gain were across the full ranges associated with childhood lung function. These associations explain the risk of childhood asthma to a substantial extent.

Vitamin D Status in Pregnancy and Determinants in a Southern European Cohort Study.

BACKGROUND: Population-based data on vitamin D status in pregnancy in southern European countries are scarce. We assessed the prevalence and determinants of vitamin D insufficiency and deficiency in pregnancy in Spain. METHODS: Plasma 25-hydroxyvitamin D3 (25(OH)D3) concentration was measured at the first trimester of gestation in 2,036 pregnant women from several geographical areas of Spain (latitude 39-42°N). Uni- and multivariable regression models were conducted to identify predictors of circulating 25(OH)D3 concentration and vitamin D insufficiency (20-30 ng/mL) and deficiency (<20 ng/mL). RESULTS: Thirty-one per cent and 18% of women were vitamin D insufficient and deficient, respectively. Season at blood collection, latitude, age, social class, tobacco smoking, physical activity and use of vitamin D supplements were identified as independent determinants of 25(OH)D3 concentration. Lower risk of vitamin D insufficiency and deficiency was associated with summer season at blood collection (RR for insufficiency = 0.34, confidence intervals (CI) 0.25, 0.48; and RR for deficiency = 0.07, 95% CI 0.04, 0.12), southern latitude (RR for insufficiency = 0.71, 95% CI 0.50, 1.02; RR for deficiency = 0.60, 95% CI 0.38, 0.94); use of vitamin D supplements (RR for insufficiency = 0.50, 95% CI 0.35, 0.71; RR for deficiency = 0.24, 95% CI 0.14, 0.41); and strong physical activity (RR for insufficiency = 0.80, 95% CI 0.58, 1.09; and RR for deficiency = 0.67, 95% CI 0.46, 1.03). Higher risk of vitamin D deficiency was related to lower social class (RR = 1.94, 95% CI 1.19, 3.16) and smoking (RR = 1.76, 95% CI 1.23, 2.54). CONCLUSIONS: Vitamin D insufficiency and deficiency are highly prevalent in pregnancy. Recommendations and policies to detect and prevent hypovitaminosis D during pregnancy should be developed taking into account the associated factors.

Prenatal exposure to bisphenol A and phthalates and childhood respiratory tract infections and allergy.

BACKGROUND: There is growing concern that prenatal exposure to bisphenol A (BPA) and phthalates, which are widely used in consumer products, might affect susceptibility to infections and the development of allergy and asthma in children, but there are currently very few prospective studies. OBJECTIVE: We sought to evaluate whether prenatal exposure to BPA and phthalates increases the risk of respiratory and allergic outcomes in children at various ages from birth to 7 years. METHODS: We measured BPA and metabolites of high-molecular-weight phthalates, 4 di-(2-ethylhexyl) phthalate (DEHP) metabolites (Σ4DEHP) and mono-benzyl phthalate (MBzP), and 3 low-molecular-weight phthalate (LMWP) metabolites (Σ3LMWP) in urine samples collected during the first and third trimesters in pregnant women participating in the Infancia y Medio Ambiente-Sabadell birth cohort study. The occurrence of chest infections, bronchitis, wheeze, and eczema in children was assessed at ages 6 and 14 months and 4 and 7 years through questionnaires given to the mothers. Atopy (specific IgE measurement) and asthma (questionnaire) were assessed at ages 4 and 7 years, respectively. RESULTS: The relative risks (RRs) of wheeze (RR, 1.20; 95% CI, 1.03-1.40; P = .02), chest infections (RR, 1.15; 95% CI, 1.00-1.32; P = .05), and bronchitis (RR, 1.18; 95% CI, 1.01-1.37; P = .04) at any age increased for each doubling in concentration of maternal urinary BPA. Σ4DEHP metabolites were associated with the same outcomes (wheeze: RR, 1.25; 95% CI, 1.04-1.50, P = .02; chest infections: RR, 1.15; 95% CI, 0.97-1.35; P = .11; bronchitis: RR, 1.20; 95% CI, 1.01-1.43; P = .04). MBzP was associated with higher risk of wheeze (RR, 1.15; 95% CI, 1.00-1.33; P = .05). The risk of asthma at age 7 years was also increased with increasing prenatal BPA, Σ4DEHP, and MBzP exposure. There were no other exposure-outcome associations. CONCLUSIONS: Prenatal exposure to BPA and high-molecular-weight phthalates might increase the risk of asthma symptoms and respiratory tract infections throughout childhood.