Determinants of baseline lung function and bronchodilator response in 4-year-old children.

The prolonged period required for maturation of the respiratory system makes it vulnerable to environmental exposure. This study aimed to investigate the association between early-life factors and lung function in preschool children. Children aged 4 years, who were included in a prospective birth cohort, underwent lung function testing at baseline (n=535) and after bronchodilation (n=498) by forced oscillations. Information on symptoms and exposures was collected through half-yearly questionnaires. Allergen-specific serum IgE was quantified at 1 and 4 years. Multiple linear regression analysis showed that the baseline respiratory resistance and reactance area were larger in the children with previous wheeze, those with early-onset sensitisation to inhalant allergens and those who were smaller. Furthermore, children with previous lower respiratory tract infections exhibited higher baseline resistance values. The baseline resistance was the only independent determinant of the bronchodilator-induced change in resistance, whereas current height and baseline reactance area were independently associated with the change in reactance area. In conclusion, previous lower respiratory tract infections, the timing of previous wheeze, inhalant sensitisation and current height independently influence the baseline lung function of 4-year-old children, whereas baseline lung function is the principal determinant of the bronchodilator response.

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

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

Nocturnal gastro-oesophageal reflux, asthma and symptoms of OSA: a longitudinal, general population study.

Nocturnal gastro-oesophageal reflux (nGOR) is associated with asthma and obstructive sleep apnoea (OSA). Our aim was to investigate whether nGOR is a risk factor for onset of asthma and onset of respiratory and OSA symptoms in a prospective population-based study. We invited 2640 subjects from Iceland, Sweden and Belgium for two evaluations over a 9-year interval. They participated in structured interviews, answered questionnaires, and underwent spirometries and methacholine challenge testing. nGOR was defined by reported symptoms. Subjects with persistent nGOR (n=123) had an independent increased risk of new asthma at follow-up (OR 2.3, 95% CI 1.1-4.9). Persistent nGOR was independently related to onset of respiratory symptoms (OR 3.0, 95% CI 1.6-5.6). The risk of developing symptoms of OSA was increased in subjects with new and persistent nGOR (OR 2.2, 95% CI 1.3-1.6, and OR 2.0, 95% CI 1.0-3.7, respectively). No significant association was found between nGOR and lung function or bronchial responsiveness. Persistent symptoms of nGOR contribute to the development of asthma and respiratory symptoms. New onset of OSA symptoms is higher among subjects with symptoms of nGOR. These findings provide evidence that nGOR may play a role in the genesis of respiratory symptoms and diseases.

Early exposure to solid foods and the development of eczema in children up to 4 years of age.

Early exposure to solid foods in infancy has been associated with the development of allergic diseases. However, scientific evidence for this is conflicting. The aim of this study was to examine the association between early exposure to solid foods in the infant's diet and the development of eczema up to 4 years of age. We conducted an etiologic case-control study nested in the PIPO cohort (Prospective Cohort on the Influence of Perinatal Factors on the Occurrence of Asthma and Allergies). In this cohort data on nutrition, environmental exposures and parent-reported eczema were collected prospectively starting from 5 months pregnancy by means of questionnaires administered during two home visits and semi-annual postal questionnaires. In addition, detailed information on the timing of introduction of solid foods at individual food item level was collected at 1 year of age. Adjusted odds ratios and 95% confidence intervals were computed using logistic regression analysis as a measure of association between eczema and the timing of exposure to solid foods. Early introduction (within the first 4 months) of solid foods was inversely associated with eczema up to 4 years of age (adj OR: 0.49; 95% CI: 0.32-0.74). Moreover, we found that early exposure to solid foods was associated with a reduced risk for eczema only among children with allergic parents (adj OR: 0.35; 95% CI: 0.20-0.63), whereas no significant effect was found among children with non-allergic parents (adj OR: 0.69; 95% CI: 0.37-1.29). The results of this study show that early exposure to solid foods is associated with less parent-reported eczema in children, particularly among children with allergic parents. Therefore, the current study does not support a delayed introduction of solid foods for the prevention of eczema in childhood.

The influence of parental educational level on the development of atopic sensitization, wheezing and eczema during the first year of life.

Several studies have investigated the association between socioeconomic status and the occurrence of allergies. Nevertheless, the results remain contradictory. The aim of this study was to evaluate the associations between parental education and the occurrence of atopic sensitization, recurrent wheezing and eczema during the first year of life, differentiating between atopic and non-atopic disorders based on specific serum IgE. We conducted an aetiological study in 690 children, based on a prospective birth cohort project in which environmental and health information was gathered using questionnaires. At the age of 1 yr a blood sample was taken for quantification of specific IgE. Adjusted odds ratios and 95% confidence intervals were computed as measures of association between the outcomes and parental education. Parental educational level was positively associated with the occurrence of atopic sensitization (OR: 2.1; 95% CI: 1.0-4.4) and eczema (OR: 1.9; 95% CI: 1.1-3.4), but negatively with the occurrence of recurrent wheezing (OR: 0.4; 95% CI: 0.2-0.8) in the first year of life. Atopic recurrent wheezing was positively associated with the education of the parents, whereas non-atopic recurrent wheezing was negatively associated. When maternal and paternal education were considered separately, only maternal education had a significant influence. Our results suggest that aspects associated with a high maternal educational level may play an important role in the development of atopic disorders.

Is breast feeding a risk factor for eczema during the first year of life?

Breast feeding (BF) provides many advantages to the offspring; however, at present there is an ongoing debate as to whether or not it prevents allergic diseases. The aim of the current study was to investigate the effect of duration of BF on eczema in the first year of life. A birth cohort of 1128 infants was followed prospectively from 5 months of pregnancy. Data were collected using questionnaires, a medical examination and blood tests for allergy at the age of 1 yr. Breast feeding was not statistically significant associated with eczema in the first year of life [adj ORs with 95% CIs: 0.8 (0.4-1.3), 0.8 (0.5-1.3) and 1.0 (0.6-1.5) for BF duration of 1-6 wk, 7-12 wk and > or = 13 wk, respectively]. Eczema was positively associated with atopy and educational level of the mother, use of antibiotics in pregnancy and passive smoking by the child during the first 12 months. Regular postnatal contact of the infants with dogs was inversely associated with eczema. Breast feeding was positively associated with eczema among children with non-atopic parents [adj ORs with 95% CIs: 2.1 (0.4-10.6), 2.2 (0.4-11.3) and 1.9 (0.4-8.5) for BF duration of 1-6 wk, 7-12 wk and > or = 13 wk, respectively], whereas an inverse association was found among children with atopic parents [adj ORs with 95% CIs: 0.6 (0.3-1.3), 0.7 (0.3-1.4) and 0.9 (0.5-1.7) for the same BF durations]. However, these associations were not statistically significant. Breast feeding has no significant effect on the prevalence of eczema in the first year of life. The effect of BF on eczema in children depends on parental atopy.