Maternal intake of vitamin D during pregnancy and risk of recurrent wheeze in children at 3 y of age

BACKGROUND: Vitamin D deficiency and asthma are common at higher latitudes. Although vitamin D has important immunologic effects, its relation with asthma is unknown. OBJECTIVE: We hypothesized that a higher maternal intake of vitamin D during pregnancy is associated with a lower risk of recurrent wheeze in children at 3 y of age. DESIGN: The participants were 1194 mother-child pairs in Project Viva-a prospective prebirth cohort study in Massachusetts. We assessed the maternal intake of vitamin D during pregnancy from a validated food-frequency questionnaire. The primary outcome was recurrent wheeze, ie, a positive asthma predictive index (>or=2 wheezing attacks among children with a personal diagnosis of eczema or a parental history of asthma). RESULTS: The mean (+/-SD) total vitamin D intake during pregnancy was 548 +/- 167 IU/d. By age 3 y, 186 children (16%) had recurrent wheeze. Compared with mothers in the lowest quartile of daily intake (median: 356 IU), those in the highest quartile (724 IU) had a lower risk of having a child with recurrent wheeze [odds ratio (OR): 0.39; 95% CI: 0.25, 0.62; P for trend < 0.001]. A 100-IU increase in vitamin D intake was associated with lower risk (OR: 0.81; 95% CI: 0.74, 0.89), regardless of whether vitamin D was from the diet (OR: 0.81; 95% CI: 0.69, 0.96) or supplements (OR: 0.82; 95% CI: 0.73, 0.92). Adjustment for 12 potential confounders, including maternal intake of other dietary factors, did not change the results. CONCLUSION: In the northeastern United States, a higher maternal intake of vitamin D during pregnancy may decrease the risk of recurrent wheeze in early childhood.     

Maternal antioxidant intake in pregnancy and wheezing illnesses in children at 2 y of age

BACKGROUND: Low intakes of dietary antioxidants may contribute to increases in asthma and allergy. OBJECTIVE: We investigated the association of maternal total intakes (foods + supplements) of 10 antioxidant nutrients during pregnancy with wheezing and eczema in 2-y-old children. DESIGN: Subjects were 1290 mother-child pairs in an ongoing cohort study. Maternal dietary and supplement intakes were assessed by using a validated food-frequency questionnaire administered in the first and second trimesters. Antioxidant nutrient intakes were calculated, and the mean for each nutrient was considered to be the exposure during pregnancy. The outcomes of interest were any wheezing by the child during either the first or second year of life, recurrent wheezing in both years, and eczema in either the first or second year. RESULTS: No association was observed between maternal total intake of any antioxidant nutrient and eczema. In multivariate logistic regression models, the highest quartile compared with the lowest quartile of maternal total intakes of vitamin E [odds ratio (OR): 0.70; 95% CI: 0.48, 1.03] and zinc (OR: 0.59; 95% CI: 0.41, 0.88) was inversely associated with any wheezing at 2 y of age (P for trend = 0.06 and 0.01 over quartiles of intake for vitamin E and zinc, respectively). Similar results were obtained for recurrent wheezing at 2 y of age with vitamin E (OR: 0.49; 95% CI: 0.27, 0.90) and zinc (OR: 0.49; 95% CI: 0.27, 0.87) (P for trend = 0.05 and 0.06 over quartiles of intake for vitamin E and zinc, respectively). CONCLUSION: Our results suggest that higher maternal total intakes of antioxidants during pregnancy may decrease the risks for wheezing illnesses in early childhood.     

The impact of parental smoking on asthma and wheezing. SIDRIA Collaborative Group. Studi Italiani sui Disturbi Respiratori nell'Infanzia e l'Ambiente.

To evaluate the impact of parental smoking on childhood asthma and wheezing, we studied two random samples of subjects ages 6-7 and 13-14 years in ten areas of northern and central Italy. Standardized questionnaires were completed by parents of 18,737 children and 21,068 adolescents (response rates, 92.8% and 96.3%, respectively) about their smoking habits and the respiratory health of their children. Adolescents were asked about their respiratory health and personal smoking. We compared two groups of cases with healthy subjects: (1) "current asthma" (children, 5.2%; adolescents, 6.2%) and (2) "current wheezing" not labeled as asthma (children = 4.5%, adolescents = 8.5%). Exposure to smoke of at least one parent increased the relative risk of current asthma among children [odds ratio (OR) = 1.34; 95% confidence interval (CI) = 1.11-1.62] and of current wheezing among adolescents (OR = 1.24; 95% CI = 1.07-1.44). Maternal smoking had a stronger effect than paternal smoking. Maternal smoking during pregnancy was associated with current asthma (OR = 1.62; 95% CI = 1.34-1.96) and current wheezing in children (OR = 1.31; 95% CI = 1.06-1.62); the effects were lower among adolescents. Among subjects with a negative history of parental asthma, maternal smoking was associated with current wheezing in both age groups, whereas among those with a positive history of parental asthma it was associated with current asthma in children, but not in adolescents. We estimated that 15% (95% CI = 12-19) of the current asthma cases among children and 11% (95% CI = 8.3-14) of the current wheezing cases among adolescents are attributable to parental smoking in Italy.     

Maternal diet during pregnancy in relation to eczema and allergic sensitization in the offspring at 2 y of age

BACKGROUND: Maternal diet during pregnancy might be one of the factors that influences fetal immune responses associated with childhood allergy. OBJECTIVE: We analyzed the association between maternal diet during the last 4 wk of pregnancy and allergic sensitization and eczema in the offspring at 2 y of age. DESIGN: Data from 2641 children at 2 y of age were analyzed within a German prospective birth cohort study (LISA). Maternal diet during the last 4 wk of pregnancy was assessed with a semiquantitative food-frequency questionnaire, which was administered shortly after childbirth. RESULTS: High maternal intake of margarine [adjusted odds ratio (aOR): 1. 49; 95% CI: 1.08, 2.04] and vegetable oils (aOR: 1.48; 95% CI: 1.14, 1.91) during the last 4 wk of pregnancy was positively associated and high maternal fish intake (aOR: 0.75; 95% CI: 0.57, 0.98) was inversely associated with eczema during the first 2 y in the offspring. High celery (aOR: 1.85; 95% CI: 1.18, 2.89) and citrus fruit (aOR: 1.73; 95% CI: 1.18, 2.53) intakes increased the risk of sensitization against food allergens. In turn, sensitization against inhalant allergens was positively related to a high maternal intake of deep-frying vegetable fat (aOR: 1.61; 95% CI: 1.02, 2.54), raw sweet pepper (aOR: 2.16; 95% CI: 1.20, 3.90), and citrus fruit (aOR: 1.72; 95% CI: 1.02, 2.92). CONCLUSIONS: We suggest that the intake of allergenic foods and foods rich in n-6 polyunsaturated fatty acids during pregnancy may increase and foods rich in n-3 polyunsaturated fatty acids may decrease the risk of allergic diseases in the offspring.     

Risk factors for recurrent wheezing in children under 13 years old in the South of Brazil]

OBJECTIVE: To study the prevalence of and major factors associated with recurrent wheezing in children younger than 13 years of age in the urban area of Rio Grande, in the state of Rio Grande do Sul, Brazil. METHODS: The presence of recurrent wheezing was investigated in a cohort as part of a cross-sectional study that was begun in 1997 that focused on the morbidity from respiratory diseases in children then between 0 and 5 years of age. During home visits in 2004 a standardized questionnaire given by trained interviewers was used to obtain information concerning the family's socioeconomic and living conditions, maternal care during pregnancy and delivery, and children's current and previous morbidity patterns. The statistical analysis included the calculation of the odds ratio (OR) and 95% confidence interval (95% CI), with nonconditional logistic regression adjustment for potential confounding factors, according to a predefined hierarchical model. RESULTS: Of the 775 children studied in 1997, 685 were located in 2004 (loss of 11.6%). In this group, the prevalence of recurrent wheezing at the time of the interview was 27.9%. After adjustment, the risk factors were: current rhinitis (OR=45.7; 95% CI: 24.2 to 86.5), use of wood stove for cooking (OR=2.7; 95% CI: 1.4 to 4.9), child's history of acute respiratory infection (OR=2.1; 95% CI: 1.3 to 3.5), bottle feeding (OR=2.1; 95% CI: 1.1 to 3.8), history of asthma in siblings (OR=1.9; 95% CI: 1.2 to 3.2), maternal history of asthma (OR=1.8; 95% CI: 1.1 to 2.9), and fewer than six prenatal medical consultations (OR=1.6; 95% CI: 1.1 to 2.4). Paternal schooling<9 years was a protective factor against recurrent wheezing (OR=0.6; 95% CI: 0.4 to 0.9). CONCLUSIONS: These results suggest that the management of recurrent wheezing and asthma must consider checking for and simultaneously treating rhinitis. The measures to minimize the effects of recurrent wheezing should include educational and treatment programs focusing on asthma.     

Parental smoking and respiratory illnesses in Australian children aged 0–4 years: ABS 1989–90 National Health Survey results

Objective: This study investigated the associations between parental smoking and respiratory infections in Australian children aged 0–4 years.
Methods: Data from the ABS 1989–90 National Health Survey were used. The exposure variables examined were maternal, paternal and combined family smoking. Outcome variables were parent-reported chronic or recent asthma, asthma wheeze, bronchitis, influenza, common cold, cough, otitis media and other respiratory conditions. Logistic regression techniques were used to control for confounding by socio-economic status, child's sex, maternal education, place of residence, ethnicity and family size.
Results: Of the 4,281 children in the sample, 45% lived in households with one or more current smokers and 29% had a mother who smoked. Maternal (but not paternal) smoking was significantly associated with asthma (OR 1.52, 95% CI 1.19–1.94) and asthma wheeze (OR 1.51, 95% CI 1.26–1.80). No other significant associations were observed. Positive and significant dose response relationships were found between the amount of maternal smoking and both asthma variables. Population attributable risks were calculated and almost 13% of asthma and asthma wheeze in 0–4 year old Australian children in 1989–90 was estimated to be due to maternal smoking.
Conclusion: Large numbers of Australian children live in households with smokers. This study, like others, has shown an association between maternal smoking and respiratory illnesses in young children. Further strategies are needed to prevent or reduce young children's exposure to environmental tobacco smoke in their homes.     

Maternal infections in pregnancy and the development of asthma among offspring.

BACKGROUND: Previous studies have suggested that asthma phenotype could probably be programmed before birth. The current study examined the impact of maternal vaginitis and febrile infections during pregnancy on the subsequent development of asthma among children. METHODS: The analyses were based on 8088 children from the northern Finland birth cohort, 1985-1986. RESULTS: The prevalence of asthma at age 7 was 3.5%. Children had a higher risk of asthma if their mothers experienced vaginitis and febrile infections during pregnancy, odds ratio (OR) = 1.41, (95% CI: 1.08-1.84) and 1.65 (95% CI: 1.25-2.18), respectively, after adjusting for other covariates. There was a clear time trend in risk of childhood asthma corresponding to the timing of maternal febrile infections in pregnancy. The adjusted OR for the first, second and third trimesters were 2.08 (95% CI: 1.13-3.82), 1.73 (95% CI: 1.09-2.75) and 1.44 (95% CI: 0.97-2.15), respectively. Maternal history of allergic diseases, birthweight <2500 g and male gender also seemed to be risk factors for childhood asthma. CONCLUSIONS: Our results suggest that further investigation of the relation of maternal infections during pregnancy to asthma among children seems warranted.     

孕期摄入维生素D对婴幼儿哮喘发生率影响的系统回顾和荟萃分析

目的 进行孕期摄入维生素D对婴幼儿哮喘发生率影响的系统分析。方法 检索中国知网、万方数据库、维普科技期刊数据库、PubMed数据库、OVID数据库,收集国内外关于孕期摄入维生素D对婴幼儿哮喘发生率影响的研究进行Meta分析。结果 5篇前瞻性队列研究文献和4篇RCT文献纳入研究。1)对5项前瞻性队列研究进行描述性分析显示,孕期饮食维生素D摄入量高的孕妇比摄入量低的孕妇其后代发生哮喘及喘息的几率较小,差异均具有统计学意义。2)对4项RCT中的2项进行Meta分析,共1 355组孕妇-婴幼儿纳入研究,其中补充维生素D组683例,安慰剂对照组672组,结果显示补充维生素D组的孕妇比安慰剂组的孕妇后代发生婴幼儿哮喘的风险较小(OR=0.71,95%CI:0.54～0.92,P=0.01)。结论 孕期摄入较大剂量的维生素D有助于减少婴幼儿哮喘的发生率。     

Ethnic variation in childhood asthma and wheezing illnesses: findings from the Millennium Cohort Study

BACKGROUND: It is not clear how respiratory morbidity during early childhood varies across ethnic groups in the UK. This article seeks to determine whether asthma and wheeze illnesses during early childhood differ across ethnic groups and what factors explain observed differences. METHODS: Data from the UK Millennium Cohort Study on 14,630 children were analyzed from the second sweep of interviews. Parental interviews were conducted when the cohort member was aged approximately 3(1/2) years. Data collected included the occurrence of asthma and wheezing symptoms, biological and socio-economic factors and markers of cultural tradition. RESULTS: At age 3, 12.3% (n = 1,902) of children had ever had asthma and 20.0% (n = 3,030) had wheezed in the last 12 months. 18.2% of Black Caribbean children and 5.0% of Bangladeshi children reported ever asthma compared with 11.6% of White children. 25.5% of Black Caribbean children and 8.7% of Bangladeshi reported recent wheeze compared with 19.4% of White children. After adjustments, the disadvantage in asthma and recent wheeze for Black Caribbeans was mostly explained by socio-economic factors (adjusted odds ratios (OR) for asthma 1.42, 95% confidence interval (CI) 0.96-2.09; recent wheeze 1.18, 0.85-1.64). The Bangladeshi advantage lost statistical significance, mostly due to adjustment for markers of cultural tradition (adjusted OR for asthma 0.40, 95% CI 0.15-1.09; recent wheeze 0.44, 0.18-1.19). CONCLUSION: Our results point to the need to locate child health within the unique context of each ethnic group and to recognize that potential explanations for observed differences do not necessarily hold for all groups.     

High circulating folate and vitamin B-12 concentrations in women during pregnancy are associated with increased prevalence of atopic dermatitis in their offspring

Recent studies suggest that in utero exposure of methyl donors influences programming of the fetal immune system in favor of development of allergic disease. The aim of this study was to assess whether the MTHFR C677T polymorphism, folic acid supplementation, and circulating folate and vitamin B-12 concentrations during pregnancy were associated with wheezing, shortness of breath, and atopic dermatitis in offspring. The study was a population-based birth cohort from fetal life until 48 mo (n = 8742). The use of folic acid supplementation during pregnancy was assessed by questionnaire. Plasma folate and serum vitamin B-12 concentrations and the MTHFR C677T polymorphism were available from blood collected in early pregnancy. Atopic dermatitis, wheezing, and shortness of breath in the offspring were assessed by parental-derived questionnaires at 12, 24, 36, and 48 mo. Maternal folate >16.2 nmol/L and vitamin B-12 >178 pmol/L were positively associated with the development of atopic dermatitis [adjusted OR: 1.18 (95% CI: 1.05-1.33) and adjusted OR: 1.30 (95% CI: 1.06-1.60) for the highest quartiles of folate and vitamin B-12 concentrations, respectively] but not with wheezing and shortness of breath. Maternal MTHFR C677T polymorphism and folic acid supplementation were not associated with wheezing, shortness of breath, and atopic dermatitis. No interactions were found by age, family history of atopy, folic acid supplementation, MTHFR C677T polymorphism, or maternal smoking (P-interaction > 0.10). High folate and vitamin B-12 levels during pregnancy are associated with increased prevalence of atopic dermatitis in the offspring. Potential risks of high folate and vitamin B-12 concentrations on allergic outcomes should be evaluated when discussing mandatory fortification programs.     

Maternal asthma and risk of preterm delivery

PURPOSE: We studied the relation between maternal history of asthma and preterm delivery. METHODS: The 312 preterm delivery cases, studied in aggregate, and in subgroups (spontaneous preterm labor, preterm premature rupture of membranes, medically induced preterm delivery), were compared with 424 randomly selected women who delivered at term. Maternal medical records provided information on maternal lifetime asthma status, pregnancy outcome, and sociodemographic characteristics. Using multivariate logistic regression, we derived maximum likelihood estimates of adjusted odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Maternal history of asthma was associated with an increased risk of preterm delivery overall (OR = 2.37; 95% CI 1.15-4.88). Analyses of preterm delivery sub-groups indicated that maternal history of asthma was associated with at least a doubling in risk of spontaneous preterm labor (OR = 2.35; 95% CI 0.84-6.58) and medically induced preterm delivery (OR = 2.69; 95% CI 1.11-6.53), though only the latter approached statistical significance. There was some evidence of a modest association between maternal asthma and risk of preterm premature rupture of membranes (OR = 1.63; 95% CI 0.50-5.33). CONCLUSIONS: These results support the hypothesis that maternal asthma is associated with an increased risk of preterm labor and delivery.     

Child Asthma and Change in Elevated Depressive Symptoms Among Mothers of Children of a Birth Cohort from Quebec

The authors examined the association between maternal reports of child asthma attacks since birth and occurrence of elevated maternal depressive symptoms at seventeen months postpartum in the present study. The modifying role of poverty in this association was also examined. Data from n = 1,696 mother–child dyads from the Quebec Longitudinal Study of Child Development, a birth cohort of children born in 1998, were used. Maternal depressive symptoms were measured with an abridged and validated twelve-item version of the Center for Epidemiologic Studies Depression Scale. Maternal reports of child asthma attacks since birth in relation to the occurrence of maternal depressive symptoms at 17 months postpartum and the potential modifying role of poverty were tested using multiple logistic regression models. When mothers reported child asthma attacks, those without elevated depressive symptoms at 5 months postpartum had lower odds of elevated depressive symptoms one year later (OR = 0.2, 95% CI: 0.1–0.7). Poverty was associated with increased odds of elevated maternal depressive symptoms (OR = 2.4, 95% CI: 1.5–3.9), without interacting with child asthma. Through this study, the authors suggest that in mothers without elevated symptoms at 5 months, reported child asthma attacks since birth did not contribute one year later to new occurrence of depressive symptoms.     

Child asthma and change in elevated depressive symptoms among mothers of children of a birth cohort from Quebec

The authors examined the association between maternal reports of child asthma attacks since birth and occurrence of elevated maternal depressive symptoms at seventeen months postpartum in the present study. The modifying role of poverty in this association was also examined. Data from n = 1,696 mother-child dyads from the Quebec Longitudinal Study of Child Development, a birth cohort of children born in 1998, were used. Maternal depressive symptoms were measured with an abridged and validated twelve-item version of the Center for Epidemiologic Studies Depression Scale. Maternal reports of child asthma attacks since birth in relation to the occurrence of maternal depressive symptoms at 17 months postpartum and the potential modifying role of poverty were tested using multiple logistic regression models. When mothers reported child asthma attacks, those without elevated depressive symptoms at 5 months postpartum had lower odds of elevated depressive symptoms one year later (OR = 0.2, 95% CI: 0.1-0.7). Poverty was associated with increased odds of elevated maternal depressive symptoms (OR = 2.4, 95% CI: 1.5-3.9), without interacting with child asthma. Through this study, the authors suggest that in mothers without elevated symptoms at 5 months, reported child asthma attacks since birth did not contribute one year later to new occurrence of depressive symptoms.     

Maternal Prepregnancy Obesity is an Independent Risk Factor for Frequent Wheezing in Infants by Age 14 Months

Background: Maternal prepregnancy obesity has been linked to the offspring's risk for subsequent asthma. We determined whether maternal obesity is associated with increased risk of wheezing phenotypes early in life. Methods: We used data on 1107 mother–child pairs from two birth cohorts from the INMA–INfancia y Medio Ambiente project. Maternal height was measured and prepregnancy weight self‐reported at enrolment (on average at 13.7 ± 2 weeks of gestation). Maternal prepregnancy body mass index was categorised as underweight, normal, overweight and obese according to WHO recommendations. Information on child's wheezing was obtained through questionnaires up to the age of 14 (±1) months. Wheezing was classified as infrequent (<4 reported wheezing episodes) or frequent (≥4 episodes). Weight and length of infants were measured by trained study staff at 14.6 (±1) months of age and weight‐for‐length z‐scores computed. Results: Although maternal obesity did not increase the risk of the child to have any or infrequent wheezing, children of obese mothers were more likely to have frequent wheezing than children of normal‐weight mothers (11.8% vs. 3.8%; P = 0.002). In fully adjusted multinomial logistic regression models, including infants' weight‐for‐length z‐scores and other covariates, maternal prepregnancy obesity was associated with increased risk of frequent [adjusted relative risk (RR) 4.18, 95% confidence interval (CI) 1.55, 11.3] but not infrequent (RR 1.05 [95% CI 0.55, 2.01]) wheezing in their children. Conclusions: Maternal prepregnancy obesity is independently associated with an increased risk of frequent wheezing in the infant by the age of 14 months. These findings add evidence on the potential effects of in utero exposures on asthma‐related phenotypes.     

Insufficient vitamin D intakes among pregnant women

Vitamin D has an important role in pregnancy in promoting fetal skeletal health. Maternal dietary intake is a key factor influencing both maternal and fetal status. There are limited data available on food groups contributing to vitamin D intake in pregnancy. The aim of this study was to determine dietary intakes of vitamin D throughout pregnancy in 64 women and to determine the main food groups contributing to vitamin D intake. Results showed that median dietary intakes of vitamin D ranged from 1.9-2.1?μg/d during pregnancy, and were 80% below the current recommendation. The principal food groups contributing to vitamin D intake were meat, egg and breakfast cereal groups. Oily fish, the best dietary source of vitamin D, was consumed by <25% of women. These data call for more education; they question the role of vitamin D supplementation and highlight the contribution of other food groups more frequently consumed, namely, breakfast cereals, meat and eggs.     

Race, asthma, and persistent wheeze in Philadelphia schoolchildren.

OBJECTIVES: Many studies show asthma to be more common in Black than in White children. This study assessed how much of this difference remains after adjustment for other potentially race-associated predictors of asthma. METHODS: We assessed the predictors of active diagnosed asthma and persistent wheeze in 1416 Black and White Philadelphia children aged 9 to 11 years, as reported by parents. RESULTS: Black race remained a significant predictor of active diagnosed asthma (odds ratio [OR] = 2.3; 95% confidence interval [CI] = 1.3, 4.1) but not of persistent wheeze (OR = 1.0; 95% CI = 0.6, 1.8). The excess risk of asthma in Black children was not appreciably altered by adjustment for other demographic and environmental factors. CONCLUSIONS: Black race is an important risk factor for active diagnosed asthma in these urban children, a relationship not explained by social factors. This finding and the lack of an association of race with persistent wheeze after adjustment for social factors suggest that race may be more important to the acquisition of an asthma diagnosis than to the prevalence of the symptoms.     

Self-reported asthma symptoms in children and adults of Bangladesh: findings of the National Asthma Prevalence Study

BACKGROUND: No population-based studies to determine the magnitude of the asthma problem have been carried out in Bangladesh. This study aimed to define the prevalence of asthma as well as to identify the risk factors of asthma in the general population of Bangladesh. METHODS: A cross-sectional study was conducted from January 1999 to August 1999 on 5642 Bangladeshi people. Data were collected from randomly selected primary sampling units of 8 municipality blocks of 4 large metropolitan cities, 12 municipality blocks of 6 district towns and 12 villages of 6 districts chosen randomly from all 64 districts of the country. Face-to-face interviews were performed with the housewives or other guardians at the household level using a structured questionnaire. RESULTS: The prevalence of asthma (wheeze in the last 12 months) was 6.9% (95% CI : 6.2-7.6). The prevalence of other asthma definitions were: ever wheeze (lifetime wheeze) 8.0% (95% CI : 7.3-8.7); perceived asthma (perception of having asthma) 7.6% (95% CI : 6.9-8.3); doctor diagnosed asthma (diagnosis of asthma by any category of doctor either qualified or unqualified) 4.4% (95% CI : 3.9-4.9). The prevalence of asthma in children (5-14 years) was higher than in adults (15-44 years) (7.3% versus 5.3%; odds ratio [OR] = 1.41, 95% CI : 1.09-1.82). Asthma in children was found to be significantly higher in households with 相似文献   

Prenatal exposure to bisphenol A and child wheeze from birth to 3 years of age

Background: Bisphenol A (BPA), an endocrine-disrupting chemical that is routinely detected in > 90% of Americans, promotes experimental asthma in mice. The association of prenatal BPA exposure and wheeze has not been evaluated in humans.Objective: We examined the relationship between prenatal BPA exposure and wheeze in early childhood.Methods: We measured BPA concentrations in serial maternal urine samples from a prospective birth cohort of 398 mother–infant pairs and assessed parent-reported child wheeze every 6 months for 3 years. We used generalized estimating equations with a logit link to evaluate the association of prenatal urinary BPA concentration with the dichotomous outcome wheeze (wheeze over the previous 6 months).Results: Data were available for 365 children; BPA was detected in 99% of maternal urine samples during pregnancy. In multivariable analysis, a one-unit increase in log-transformed creatinine-standardized mean prenatal urinary BPA concentration was not significantly associated with child wheeze from birth to 3 years of age, but there was an interaction of BPA concentration with time (p = 0.003). Mean prenatal BPA above versus below the median was positively associated with wheeze at 6 months of age [adjusted odds ratio (AOR) = 2.3; 95% confidence interval (CI): 1.3, 4.1] but not at 3 years (AOR = 0.6; 95% CI: 0.3, 1.1). In secondary analyses evaluating associations of each prenatal BPA concentration separately, urinary BPA concentrations measured at 16 weeks gestation were associated with wheeze (AOR = 1.2; 95% CI: 1.0, 1.5), but BPA concentrations at 26 weeks of gestation or at birth were not.Conclusions: Mean prenatal BPA was associated with increased odds of wheeze in early life, and the effect diminished over time. Evaluating exposure at each prenatal time point demonstrated an association between wheeze from 6 months to 3 years and log-transformed BPA concentration at 16 weeks gestation only.     

Effect of outdoor and indoor nitrogen dioxide on respiratory symptoms in schoolchildren

BACKGROUND: Nitrogen dioxide (NO(2)), an oxidant gas that contaminates both outdoor and indoor air, is considered to be a potential risk factor for asthma. We investigated concurrently the effects of outdoor and indoor NO(2) on the prevalence and incidence of respiratory symptoms among children. METHODS: A cohort study was carried out over 3 years on 842 schoolchildren living in seven different communities in Japan. Indoor NO(2) concentrations over 24 hours were measured in both winter and summer in the homes of the subjects, and a 3-year average of the outdoor NO(2) concentration was determined for each community. Respiratory symptoms were evaluated every year from responses to questionnaires. RESULTS: The prevalence of bronchitis, wheeze, and asthma significantly increased with increases of indoor NO(2) concentrations among girls, but not among boys. In neither boys nor girls were there significant differences in the prevalence of respiratory symptoms among urban, suburban, and rural districts. The incidence of asthma increased among children living in areas with high concentrations of outdoor NO(2). Multiple logistic regression analysis showed that a 10 parts per billion (ppb) increase of outdoor NO(2) concentration was associated with an increased incidence of wheeze and asthma (odds ratios [OR] = 1.76, 95% CI : 1.04-3.23 and OR = 2.10, 95% CI : 1.10-4.75, respectively), but that no such associations were found with indoor NO(2) concentration (OR = 0.73, 95% CI : 0.45-1.14 and OR = 0.87, 95% CI : 0.51-1.43, respectively). CONCLUSIONS: These findings suggest that outdoor NO(2) air pollution may be particularly important for the development of wheeze and asthma among children. Indoor NO(2) concentrations were associated with the prevalence of respiratory symptoms only among girls. Girls may be more susceptible to indoor air pollution than boys.     

Risk factors for wheezing in Ukrainian children: Ukraine European Longitudinal Study of Pregnancy and Childhood Group

The prevalence of wheezing in children varies widely around the world. The reasons for this geographic variability remain unclear but may be related in part to exposures in the home environment during pregnancy and early childhood. We investigated the prenatal and early childhood risk factors for wheezing symptoms among 2127 children aged 6–8 years who were participants in the Ukrainian component of the European Longitudinal Study of Pregnancy and Childhood (ELSPAC). Cases included the 169 children whose parents answered yes to the International Study of Asthma and Allergy in Children (ISAAC) question: 'Has your child had wheezing or whistling in the chest in the past 12 months' during the ELSPAC assessment of the children at age 7. These were compared with the 1861 children in the cohort whose parents answered 'no' to this question.
Factors significantly associated with increased risk of wheezing illness at age 7 in adjusted analyses included mother's asthma [adjusted odds ratio (OR) 3.46, 95% confidence interval (CI) 1.22, 9.85]; mother's allergy problems (OR 1.43, [1.00, 2.05]); rarely playing with other children at age 3 (OR 1.84, [1.09, 3.11]); water intrusion (OR 1.62, [1.09, 2.39]) and inadequate heating of the home (OR 1.52, [1.06, 2.16]) during pregnancy. Factors protective of wheezing at age 7 included being first-born (adjusted OR 0.70, 95% CI 0.50, 0.98); living in the city of Dniprodzerzynsk as compared with Kyiv (OR 0.36, [0.24, 0.54]) and weekly contact with furry animals (OR 0.44, [0.20, 0.97]) before age 3. The constellation of risk factors for wheezing in Ukrainian children is similar to that of children in other parts of the world. Known risk factors do not account for the significant between-city variability of wheezing in Ukrainian children.