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There is conflicting evidence for the relationship between parental socioeconomic position and their children's asthma. The aim of this study was to investigate relationships between parental education and respiratory symptoms in their children, distinguishing atopic and non-atopic symptoms. A cross-sectional survey among 3262 elementary school children (age 8-13) was performed; data on parental education were obtained for 3213 children. Parents completed a questionnaire on their child's allergic and respiratory symptoms, and potential explanatory variables including family history, indoor environment, and the child's medical history. Subsets of children were tested for atopy (n = 1983), lung function (n = 2325), and airway hyperresponsiveness (AHR) (n = 880). Logistic regression was used to assess relationships of health outcomes with parental education. A high parental education was associated with an increased risk of atopic sensitization to indoor allergens (OR 1.31, 95% CI 1.02; 1.69). Studied explanatory variables did not influence the relationship. In contrast, a high parental education protected children from wheeze (OR 0.77, 95% CI 0.61; 0.97). This only applied to non-atopic wheeze (OR 0.65, 95% CI 0.43; 0.99) and not to atopic wheeze (OR 0.89, 95% CI 0.60; 1.31). The protection from non-atopic wheeze in children of highly educated parents declined after adjustment for household smoking and breastfeeding (OR 0.96, 95% CI 0.58; 1.57). Similar results were observed for non-atopic and atopic rhinitis. We conclude that children from highly educated parents are protected from non-atopic respiratory symptoms, which is largely explained by a lower rate of household smoking and a higher rate of breastfeeding.

Background: Asthma and rhinitis may represent two manifestations of the same airway disease. Genetic research can increase our understanding of their common or distinct pathogenesis. IL13 and IL4R polymorphisms are associated with asthma and show gene-gene interaction in asthma. Their role in rhinitis has not been extensively studied., Methods: Association of IL13 and IL4R polymorphisms in relation to rhinitis, asthma, serum IgE and skin test response was studied in: (1) 188 trios ascertained through a proband with rhinitis who were clinically not affected by asthma; (2) 407 trios with an asthmatic proband, and (3) 118 asthma cases and 102 unrelated healthy controls using family-based association testing, logistic regression, and analysis of variance as appropriate. Gene-gene interaction was evaluated using logistic regression analysis., Results: IL13 C-1111T (rs1800925) was significantly associated with rhinitis and atopic phenotypes in rhinitis trios that were not affected by clinical asthma. IL13 Arg130Gln (rs20541) and G870A (rs1295685) were consistently associated with asthma and serum IgE in both asthma populations. IL4R Glu375Ala (rs1805011) and Ser411Leu (rs1805013) were associated with asthma in the asthma case-control population. Combining risk genotypes of IL13 Arg130Gln with IL4R Glu375Ala, and IL13 C-1111T with IL4R Ser478Pro yielded increased risks for asthma compared to their separate effects., Conclusion: IL13 polymorphisms were associated with asthma and rhinitis without clinical asthma; thus, these polymorphisms may constitute a common etiologic pathway for their development. In addition, the study replicates a previously reported interaction of IL13 and IL4R polymorphisms in asthma., (Copyright © 2010 S. Karger AG, Basel.)

A cross-sectional study showed that 130 out of 1758 (8%) primary school children without a previous asthma diagnosis had undiagnosed asthma. Thirty-eight per cent of their parents refused to visit a general practitioner for this disorder. Factors associated with the refusal were high maternal education, mild symptoms and absence of airway reversibility.

The aim of the present study was to establish the differences in dyspnoea perception between children with undiagnosed and diagnosed asthma. A cross-sectional community-based study was performed, which included a parental questionnaire on the child's respiratory health and testing of airway reversibility and bronchial hyperresponsiveness (BHR). "Diagnosed asthma" was defined by a physician's diagnosis of asthma. "Undiagnosed asthma" was defined by the presence of asthma symptoms combined with either airway reversibility or BHR without a physician's diagnosis of asthma. Only children with a positive BHR test were selected for further analysis. Perception of dyspnoea was assessed using the Borg scale and the visual analogue scale (VAS), plotted against the percentage fall in forced expiratory volume in one second and expressed as the slope of the regression line. Of the initial 1,758 participating children, 70 had undiagnosed asthma and 38 had diagnosed asthma. The Borg and VAS slopes in children with undiagnosed asthma were less steep than those of children with diagnosed asthma (Borg: 0.07 and 0.14, respectively; VAS: 0.06 and 0.11, respectively). Among children with bronchial hyperresponsiveness, those without a parent's report of physician's diagnosis of asthma had a worse perception of dyspnoea than children with diagnosed asthma.

To establish whether asthma affects physical activity levels in children (aged 7-10 years) we evaluated physical activity levels in children with undiagnosed asthma (UDA), diagnosed asthma (DA), and healthy controls (HCs). A cross-sectional community-based study was performed which included a parental questionnaire on their child's respiratory health, and testing of airway reversibility and bronchial hyperresponsiveness (BHR). DA was defined as the parents' confirmation of a physician's diagnosis of asthma in the past 12 months. UDA was defined by asthma symptoms combined with airway reversibility or BHR in children without a physician's diagnosis of asthma. Physical activity was measured during 5 days with an accelerometer and a diary, and with the habitual activity estimation scale which reviews the physical activity during the past 2 weeks. The final study population comprised 1,614 children of whom 81 (5%) had DA, 130 (8%) UDA, and 202 HCs. Baseline FEV(1) % was lowest in children with UDA (UDA FEV(1) 94% predicted, DA FEV(1) 98% predicted, HCs FEV(1) 100% predicted). Using the three methods, no differences were found in the physical activity between children with UDA, DA, and HCs. Childhood asthma does not appear to be associated with a decreased level of daily physical activity in our study population., ((c) 2007 Wiley-Liss, Inc.)

This study describes the impact of undiagnosed and diagnosed asthma on quality of life in schoolchildren aged 7-10 years and their caregivers in a cross-sectional community-based study. Diagnosed asthma was defined as the parents' confirmation of a physician's diagnosis of asthma. Undiagnosed asthma was defined by asthma symptoms combined with airway reversibility or bronchial hyperresponsiveness. Quality of life was evaluated in all children with asthma and a sample of healthy controls by the Pediatric Asthma Quality of Life Questionnaire, and by the Paediatric Asthma Caregiver's Quality of Life Questionnaire. We studied the impact of breathing problems on school absence. Compared with healthy controls, quality of life scores among children and their caregivers were lower if the child had asthma (P < 0.05), with lowest scores in diagnosed asthma (P < 0.05 compared with undiagnosed asthma). Children with asthma reported more school absence (P < 0.05), with highest absence rate in those with diagnosed asthma. In conclusion, both undiagnosed and diagnosed asthma have a significant impact on the quality of life of both children and their caregivers.

Background: Asthma and excessive body weight frequently coexist, whereas the exact relationship between the 2 diseases is unknown., Objective: To study whether asthma combined with excessive body weight has a greater effect on quality of life in children than the separate effects of asthma or excessive body weight alone., Methods: In a cross-sectional design, 1758 school children (age 7-10 years) participated: 4 study groups were composed of children with asthma and with/without excessive body weight, and healthy controls with/without excessive body weight. Diagnosis of asthma was defined by either a doctor's diagnosis or by core questions of the International Study of Asthma and Allergies in Childhood questionnaire in combination with either reversible airway obstruction or bronchial hyperresponsiveness. Excessive body weight was defined by using international cutoff points for body mass index. Quality of life was evaluated by the Pediatric Asthma Quality of Life Questionnaire., Results: For all domains of quality of life, children with both asthma and excessive body weight had lower scores than children with either asthma alone or excessive body weight alone. Compared with healthy controls, the score was 25% lower in children with asthma and excessive body weight, 14% lower in children with asthma and normal weight, and only 1% lower in overweight controls., Conclusion: Excessive body weight is associated with an additional decrease in quality of life in children with asthma., Clinical Implications: Clinicians should be aware of the interaction between asthma and excessive body weight and the effect on quality of life and should give extra attention to children with both conditions.

Background: The rise in the prevalence of asthma in western societies may be related to changed dietary habits. Epidemiological studies in children have shown inverse associations of asthma related outcomes with intake of fruits, vegetables, dairy and whole grain products, and fish. In contrast to most previous studies, we used both questionnaire and clinical data to define asthma., Methods: Intake of the abovementioned foods was studied in relation to asthma in 598 Dutch children aged 8-13 years. Dietary intake was estimated using a parent completed semi-quantitative food frequency questionnaire. Current wheeze and current asthma were defined based on questionnaire data. More complex end points were defined using information on bronchial hyperresponsiveness (BHR) and atopic sensitisation as well. Linear associations were studied using logistic regression analysis and odds ratios presented for the highest versus the lowest tertile of intake. In the final models, adjustments were made for maternal educational level, foreign descent, and total energy intake., Results: The intake of whole grain products and of fish was inversely associated with asthma. Adjusted odds ratios for the independent associations with whole grains and fish were 0.46 (95% CI 0.19 to 1.10) and 0.34 (95% CI 0.13 to 0.85) for current asthma and 0.28 (95% CI 0.08 to 0.99) and 0.12 (95% CI 0.02 to 0.66) for atopic asthma with BHR. Similar results were observed for current wheeze and atopic wheeze with BHR. Intake of (citrus) fruits, vegetables, and dairy products showed no clear associations with asthma end points., Conclusions: Our findings suggest that a high intake of whole grain products and fish may have a protective effect against asthma in children.

The result of airway challenge test with hypertonic saline (HS) is expressed as the dose causing a 15% fall in forced expiratory volume in one second (FEV1; PD15). A noncensored measure, such as the dose-response slope (DRS), allows the evaluation of the risk of asthma for subjects with a fall in FEV1 <15%. The aim of this study was to assess the relationship between airway responsiveness to HS by PD15 or DRS, asthma symptoms and markers of eosinophilic inflammation. Data on current wheeze and airway responsiveness were obtained for 1,107 children (aged 8-13 yrs). Blood eosinophils and serum eosinophil cationic protein (ECP) were assessed in subsets (n = 683 and 485). PD15 was assessed if FEV1 fell > or =15%, and the DRS was calculated for all tests. Graphs were constructed to visualise relationships with current wheeze, blood eosinophils and serum ECP. Odds ratios and Spearman's correlation coefficients were calculated to quantify these relationships. Children with features of asthma had lower PD15 and higher DRS, and separation was most pronounced for DRS. Prevalence of current wheeze increased continuously over the entire range of DRS values. Blood eosinophils were significantly higher only for the highest values of DRS. In conclusion, the continuous relationship between airway responsiveness and asthma symptoms is in favour of a noncensored measure of airway responsiveness, such as the dose-response slope.

Background: In adult asthma, bronchial hyper-responsiveness (BHR) to indirect stimuli reflects eosinophilic activation more closely than BHR to stimuli that directly cause smooth muscle contraction., Aim: To assess the relationship between BHR to the indirect stimulus hypertonic saline (HS), blood eosinophil numbers, and serum eosinophilic cationic protein (ECP) in children with and without current wheeze., Methods: A cross-sectional survey among 8-13-year-old schoolchildren, using the International Study of Asthma and Allergic disease in Childhood questionnaire, bronchial challenge with HS, skin prick tests, serum IgE, blood eosinophil counts and ECP (in a subset). Based upon the presence of current wheeze (WHE) and BHR, we defined three case groups (WHE+BHR+, WHE-BHR+, WHE+BHR-) and the reference group (WHE-BHR-). By regression analyses, each case group was compared with the reference group for differences in atopic sensitization, blood eosinophil counts and serum ECP., Results: Complete data were obtained for 470 children. BHR was present in 103 children (22%), 66 being asymptomatic and 37 symptomatic. Children of all three case groups were more often atopic. Sensitization to indoor allergens particularly occurred in children with BHR, irrespective of symptoms (P < 0.05). Children with WHE+BHR+ had highest values for blood eosinophils and serum ECP (P < 0.05). Children with WHE-BHR+ had less severe responsiveness. In atopic children with WHE-BHR+, serum ECP was higher than in children with WHE-BHR-(P < 0.05)., Conclusions: BHR to HS is associated with blood markers of eosinophilic activation, particularly in atopic children.

Background: Asthma and allergic sensitization to cats frequently coexist, although recent studies show less atopic disease among people who had pets in infancy. However, no longterm evaluations have been performed thus far., Objective: We sought to evaluate the relationship between cat ownership at different age periods (< 18, > 18, and both periods and atopic disease at age 28., Methods: Australian school children aged 8 to 10 years were recruited in 1982 and participated in follow-up surveys until 2002. Cat ownership was defined by surveys in 1992 and 2002 as having a cat before age 18 only, after age 18 only, or in both periods of life. Health outcomes were defined at a mean age of 28.5 years., Results: Complete data were available for 224 subjects, 50 of whom had a cat before 18 years of age only, 14 after age 18 only, and 70 in both periods. Compared with 90 subjects that never had a cat, having a cat before age 18 protected against atopy to outdoor allergens, airway hyperresponsiveness (AHR) to histamine, current wheeze, and current asthma (P < .05). In contrast, subjects who acquired their first cat after age 18 showed a trend toward higher prevalence rates for asthma symptoms and AHR (P > .10)., Conclusions: Having had a cat before 18 years of age protects against adult asthma and atopy.

Background: In asthma patients, bronchial hyper-responsiveness (BHR) to adenosine-5'-monophosphate (AMP) reflects bronchial inflammation more closely than BHR to methacholine. In this follow-up study we studied bronchial responsiveness to both stimuli as predictors of new-onset airway symptoms., Methods: We included 118 laboratory animal workers and bakery apprentices with a work experience of maximally 1 year. The baseline survey comprised a questionnaire, skin prick tests (SPTs) to common and work allergens, blood eosinophil counting, and bronchial challenge with methacholine and AMP. At follow-up, questionnaire and SPTs to work allergens were repeated. Airway symptoms to common allergens and work allergens were defined as nasal symptoms, chest tightness or asthma attack during or after contact with either common or work allergen. Bronchial challenge tests were analysed by BHR at a 15% fall in forced expiratory volume of 1 s (FEV1), and by dose-response-slope (DRS)., Results: Fourteen subjects (12%) developed airway symptoms to work allergens, of whom 12 had nasal symptoms. A positive SPT to work allergens occurred in 64%, and was the strongest predictor of airway symptoms [relative risk (RR) 7.5, 95% confidence interval (CI) 2.0-28.6]. Other predictors were airway symptoms to common allergens (RR 4.3, 95% CI 1.4-12.8), blood hypereosinophilia (RR 4.4, 95% CI 1.2-15.4) and BHR, with a slightly higher risk estimate for AMP than for methacholine (RRAMP 3.7, 95% CI 1.1-12.5 and RRmeth 2.8, 95% CI 1.0-8.5). The difference was more distinct analysing airway responsiveness by DRS, for which AMP predicted symptoms better than methacholine (P < 0.05)., Conclusions: Pre-existent bronchial inflammation or a preinflammatory state marked by AMP (hyper)responsiveness increases the vulnerability to develop nasal symptoms.

Background: Allergen exposure in early childhood is thought to be important for sensitization and subsequent development of asthma. Not much is known, however, about exposure of young children to allergens in the home., Objectives: This study was designed to document dust mite allergen exposure in young children, and to determine whether infants from atopic mothers (= 'high-risk' infants) are exposed to lower concentrations of house dust mite allergen than infants from non-atopic parents (= 'low-risk' infants)., Methods: Dust samples were taken in the homes of 104 infants (48 'high-risk' and 56 'low-risk' infants, selected by questionnaire) aged 3-15 months, from floors in different rooms and from the child's mattress surface., Results: The majority of the infants were found to be exposed to Der p I concentrations of more than 2000 ng/g in dust collected from the surface of their mattresses. Lower Der p I concentrations were found in mattress surface dust from the beds of infants from atopic mothers than of infants from non-atopic parents. Also, lower Der p I concentrations were found in floor dust from the homes of infants from atopic mothers. Infant beds equipped with new mattresses, new blankets and top plastic sheeting had significantly lower Der p I concentrations than beds equipped with used mattresses and blankets, without top plastic sheeting., Conclusions: Young children in the Netherlands are exposed to significant concentrations of Der p I in mattress surface dust. Allergic parents appear to provide their children with environments somewhat less rich in mite allergen than non-allergic parents.

Background Studies have suggested that early contact with pets may prevent the development of allergy and asthma. Objective To study the association between early, current and past pet ownership and sensitization, bronchial responsiveness and allergic symptoms in school children. Methods A population of almost 3000 primary school children was investigated using protocols of the International Study on Asthma and Allergies in Childhood (ISAAC). Allergic symptoms were measured using the parent-completed ISAAC questionnaire. Sensitization to common allergens was measured using skin prick tests (SPT)s and/or serum immunoglobulin (Ig)E determinations. Bronchial responsiveness was tested using a hypertonic saline challenge. Pet ownership was investigated by questionnaire. Current, past and early exposure to pets was documented separately for cats, dogs, rodents and birds. The data on current, past and early pet exposure were then related to allergic symptoms, sensitization and bronchial responsiveness. Results Among children currently exposed to pets, there was significantly less sensitization to cat (odds ratio (OR) = 0.69) and dog (OR = 0.63) allergens, indoor allergens in general (OR = 0.64), and outdoor allergens (OR = 0.60) compared to children who never had pets in the home. There was also less hayfever (OR = 0.66) and rhinitis (OR = 0.76). In contrast, wheeze, asthma and bronchial responsiveness were not associated with current pet ownership. Odds ratios associated with past pet ownership were generally above unity, and significant for asthma in the adjusted analysis (OR = 1.85), suggesting selective avoidance in families with sensitized and/or symptomatic children. Pet ownership in the first two years of life only showed an inverse association with sensitization to pollen: OR = 0.71 for having had furry or feathery pets in general in the first two years of life, and OR = 0.73 for having had cats and/or dogs in the first two years of life, compared to not having... [ABSTRACT FROM AUTHOR]