Publications (16)71.14 Total impact
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Article: Influence of Mediterranean diet on asthma in children: A systematic review and meta-analysis.
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ABSTRACT: BACKGROUND: There is epidemiological evidence that Mediterranean diet exposure is associated with lower asthma prevalence in children. We aimed to summarize the available data and to know whether the Mediterranean setting modifies this association. METHODS: The literature search, up to May 2012, was on epidemiological studies in the general population of children assessing whether adherence to Mediterranean diet (measured as a score) was associated with the prevalence of 'current wheeze'; 'current severe wheeze'; or 'asthma ever'. Odds ratios (OR) of the eight included studies compared the highest tertile of the score with the lowest. Random-effects meta-analyses for the whole group of studies and stratified by Mediterranean setting (centers <100 Km from the Mediterranean coast) were performed. Differences between strata were assessed using the Q test. RESULTS: For 'current wheeze', there was a negative significant association with the highest tertile of Mediterranean diet score (OR 0.85, 95% CI 0.75-0.98; p = 0.02), driven by Mediterranean centers (0.79, 0.66-0.94, p = 0.009), although the difference with the non-Mediterranean centers (0.91, 0.78-1.05, p = 0.18) was not significant. The results for 'current severe wheeze' were as follows: 0.82, 0.55-1.22, p = 0.330 (all); 0.66, 0.48-0.90, p = 0.008 (Mediterranean); and 0.99, 0.79-1.25, p = 0.95 (non-Mediterranean); with the difference between regions being significant. For 'asthma ever', the associations were as follows: 0.86, 0.78-0.95, p = 0.004 (all); 0.86, 0.74-1.01, p = 0.06 (Mediterranean); 0.86, 0.75-0.98; p = 0.027 (non-Mediterranean); with the difference between regions being negligible. CONCLUSIONS: Adherence to the Mediterranean diet tended to be associated with lower occurrence of the three respiratory outcomes. For current and current severe wheeze, the association was mainly driven by the results in Mediterranean populations.Pediatric Allergy and Immunology 04/2013; · 2.46 Impact Factor -
Article: Asthma phenotypes identified by latent class analysis in the ISAAC phase II Spain study.
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ABSTRACT: BACKGROUND: Classification of respiratory symptoms may help to identify different underlying asthma phenotypes reflecting differences in aetiology and prognosis of wheezing disease among children. OBJECTIVE: To determine childhood asthma phenotypes based on respiratory symptoms from a widely used questionnaire to further classify phenotypes in international settings. METHODS: Between 2000 and 2002 cross-sectional studies were performed in four centres in Spain. Parental questionnaires were used to collect information on allergic diseases in more than 4000 children aged 8-12 years. In addition, objective markers for allergic sensitization and bronchial hyperresponsiveness (BHR) were measured. Latent class analyses (LCA) were applied to identify subgroups of children according to respiratory symptoms, and then the association of these groups with relevant clinical features such as concomitant allergic disease symptoms, atopy and BHR was studied. RESULTS: We found seven classes, one corresponding to healthy children, three classes related to wheeze and three other classes mainly related to congestion and coughed-up phlegm. These tentative phenotypes differed in severity of symptoms and also in clinical correlates such as BHR and allergic sensitization. Atopy was more predominant in the 'wheeze phenotypes' whereas concomitant 'allergic' symptoms were most frequent in two of the 'wheeze phenotypes' and one of the 'cough phenotypes'. CONCLUSIONS: LCA on reported symptoms in a cross-sectional survey allowed different subgroups with meaningful clinical correlates to be defined. It remains to be investigated to what extent these groups also have different aetiologies, prognoses and therapeutic needs.Clinical & Experimental Allergy 02/2013; 43(2):223-232. · 5.03 Impact Factor -
Article: Lack of evidence for a protective effect of prolonged breastfeeding on childhood eczema: lessons from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two.
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ABSTRACT: Exclusive breastfeeding for at least 4 months is recommended by many governments and allergy organizations to prevent allergic disease. To investigate whether exclusive breastfeeding protects against childhood eczema. Study subjects comprised 51,119 randomly selected 8- to 12-year-old schoolchildren in 21 countries. Information on eczema and breastfeeding was gathered by parental questionnaire. Children were also examined for flexural eczema and underwent skin prick testing. Odds ratios (ORs) were calculated for each study centre and then pooled across populations. There was a small increase in the risk of reported 'eczema ever' in association with 'breastfeeding ever' and breastfeeding < 6 months [pooled adjusted OR 1·11, 95% confidence interval (CI) 1·00-1·22 and OR 1·10, 95% CI 1·02-1·20, respectively]. There was no significant association between reported 'eczema ever' and breastfeeding > 6 months (pooled adjusted OR 1·09, 95% CI 0·94-1·26). Risk estimates were very similar for exclusive breastfeeding < 2 months, 2-4 months and > 4 months and for eczema symptoms in the past 12 months and eczema on skin examination. As for more severe eczema, breastfeeding per se conveyed a risk reduction on sleep disturbed eczema (pooled adjusted OR 0·71, 95% CI 0·53-0·96), but this effect was lost where children had been exclusively breastfed for > 4 months (pooled adjusted OR 1·02, 95% CI 0·67-1·54). Allergic sensitization and a history of maternal allergic disease did not modify any of these findings. Although there was a protective effect of ever having been breastfed on more severe disease, we found no evidence that exclusive breastfeeding for 4 months or longer protects against eczema. Our results are consistent with findings from a recent systematic review of prospective studies. The U.K. breastfeeding guidelines with regard to eczema should be reviewed. Intervention studies are now required to explore how and when solids should be introduced alongside breastfeeding to aid protection against eczema and other allergic diseases.British Journal of Dermatology 08/2011; 165(6):1280-9. · 3.67 Impact Factor -
Article: International variations in associations of allergic markers and diseases in children: ISAAC Phase Two.
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ABSTRACT: Circulating allergen-specific IgE (sIgE) and skin prick tests (SPT) are used to define atopy. Downregulation of local inflammatory responsiveness has been proposed to explain a low prevalence of positive SPTs in less affluent countries. We analysed the association between SPTs, total and allergen-specific IgE and their relationships to allergic symptoms in centres with diverse living conditions. Cross-sectional studies of stratified random samples of 8 to 12-year-old children (n = 7461) used the standardized methodology of Phase Two of the International Study of Asthma and Allergies in Childhood (ISAAC). Symptoms of asthma, rhinitis and eczema were ascertained by parental questionnaires. Skin examination, hypertonic saline bronchial challenge, six aeroallergen SPTs and measurements of serum total IgE and sIgE were performed. In nonaffluent countries, a higher proportion of children with positive SPT had no detectable sIgE (range 37-61%) than in affluent countries (0-37%). Total serum IgE was associated with all disease outcomes among children with both positive SPT and sIgE (P < 0.001), but only with self-reported eczema in children with negative SPTs and negative sIgE. The international pattern of discordance between SPT and sIgE results did not support the downregulation hypothesis. Among children with no evidence of sensitization to common aeroallergens, increased total IgE contributes little to the risk of wheeze and rhinitis in the general population but may play a role in eczema.Allergy 12/2009; 65(6):766-75. · 6.27 Impact Factor -
Article: A multi-centre study of candidate genes for wheeze and allergy: the International Study of Asthma and Allergies in Childhood Phase 2.
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ABSTRACT: Common polymorphisms have been identified in genes suspected to play a role in asthma. We investigated their associations with wheeze and allergy in a case-control sample from Phase 2 of the International Study of Asthma and Allergies in Childhood. We compared 1105 wheezing and 3137 non-wheezing children aged 8-12 years from 17 study centres in 13 countries. Genotyping of 55 candidate single nucleotide polymorphisms (SNPs) in 14 genes was performed using the Sequenom System. Logistic regression models were fitted separately for each centre and each SNP. A combined per allele odds ratio and measures of heterogeneity between centres were derived by random effects meta-analysis. Significant associations with wheeze in the past year were detected in only four genes (IL4R, TLR4, MS4A2, TLR9, P<0.05), with per allele odds ratios generally <1.3. Variants in IL4R and TLR4 were also related to allergen-specific IgE, while polymorphisms in FCER1B (MS4A2) and TLR9 were not. There were also highly significant associations (P<0.001) between SPINK5 variants and visible eczema (but not IgE levels) and between IL13 variants and total IgE. Heterogeneity of effects across centres was rare, despite differences in allele frequencies. Despite the biological plausibility of IgE-related mechanisms in asthma, very few of the tested candidates showed evidence of association with both wheeze and increased IgE levels. We were unable to confirm associations of the positional candidates DPP10 and PHF11 with wheeze, although our study had ample power to detect the expected associations of IL13 variants with IgE and SPINK5 variants with eczema.Clinical & Experimental Allergy 12/2009; 39(12):1875-88. · 5.03 Impact Factor -
Article: How well do questionnaires perform compared with physical examination in detecting flexural eczema? Findings from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two
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ABSTRACT: Background Questionnaires are widely used in epidemiological studies to measure eczema symptom prevalence, but there are concerns regarding their accuracy if used as a diagnostic tool.Objectives To compare the performance of a validated eczema symptom questionnaire and a standardized skin examination protocol employed in the second phase of the International Study of Asthma and Allergies in Childhood (ISAAC).Methods A total of 30 358 schoolchildren aged 8–12 years from 18 countries were examined for flexural eczema. Parents also completed an eczema symptom questionnaire. We compared prevalence estimates at the population level based on the questionnaire vs. physical examination. We also compared the skin examination and the ISAAC questionnaire in making a diagnosis of flexural eczema.Results The point prevalences for flexural eczema at centre level based on a single examination were lower than the questionnaire-based 12-month period prevalences (mean centre prevalence 3·9% vs. 9·4%). Correlation between prevalences of both outcome measures was high (r = 0·77, P < 0·001). At the individual level, questionnaire-derived symptoms of ‘persistent flexural eczema in the past 12 months’ missed < 10% of cases of flexural eczema detected on physical examination. However, between 33% and 100% of questionnaire-based symptoms of ‘persistent flexural eczema in the past 12 months’ were not confirmed on examination.Conclusions ISAAC questionnaire-derived symptom prevalences are sufficiently precise for comparisons between populations. Where diagnostic precision at the individual level is important, questionnaires should be validated and potentially modified in those populations beforehand, or a standardized skin examination protocol should be used.British Journal of Dermatology 05/2009; 161(4):846 - 853. · 3.67 Impact Factor -
Article: How well do questionnaires perform compared with physical examination in detecting flexural eczema? Findings from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two.
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ABSTRACT: Questionnaires are widely used in epidemiological studies to measure eczema symptom prevalence, but there are concerns regarding their accuracy if used as a diagnostic tool. To compare the performance of a validated eczema symptom questionnaire and a standardized skin examination protocol employed in the second phase of the International Study of Asthma and Allergies in Childhood (ISAAC). A total of 30,358 schoolchildren aged 8-12 years from 18 countries were examined for flexural eczema. Parents also completed an eczema symptom questionnaire. We compared prevalence estimates at the population level based on the questionnaire vs. physical examination. We also compared the skin examination and the ISAAC questionnaire in making a diagnosis of flexural eczema. The point prevalences for flexural eczema at centre level based on a single examination were lower than the questionnaire-based 12-month period prevalences (mean centre prevalence 3.9% vs. 9.4%). Correlation between prevalences of both outcome measures was high (r = 0.77, P < 0.001). At the individual level, questionnaire-derived symptoms of 'persistent flexural eczema in the past 12 months' missed < 10% of cases of flexural eczema detected on physical examination. However, between 33% and 100% of questionnaire-based symptoms of 'persistent flexural eczema in the past 12 months' were not confirmed on examination. ISAAC questionnaire-derived symptom prevalences are sufficiently precise for comparisons between populations. Where diagnostic precision at the individual level is important, questionnaires should be validated and potentially modified in those populations beforehand, or a standardized skin examination protocol should be used.British Journal of Dermatology 05/2009; 161(4):846-53. · 3.67 Impact Factor -
Article: Effect of breastfeeding on asthma, lung function and bronchial hyperreactivity in ISAAC Phase II.
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ABSTRACT: The association between breastfeeding and wheezing, lung function and atopy was evaluated in the International Study of Asthma and Allergy in Childhood (ISAAC) Phase II. Cross-sectional studies were performed in 27 centres in 20 countries. Information on disease and exposure factors was collected by parental questionnaires. Data from 54,000 randomly selected school children (aged 8-12 yrs, 31,759 with skin prick testing) and a stratified subsample (n = 4,888) were used for testing the correlation of breastfeeding with bronchial hyperreactivity and lung function. Random effect models for meta-analysis were applied to calculate combined odds ratios (ORs). Any breastfeeding was associated with less wheeze both in affluent (adjusted OR (OR(adj)) 0.87, 95% confidence interval (CI) 0.78-0.97) and nonaffluent countries (OR(adj) 0.80, 95% CI 0.68-0.94). Further analyses revealed that this was true only for nonatopic wheeze in nonaffluent countries (OR(adj) 0.69, 95% CI 0.53-0.90). Breastfeeding was not associated with atopic wheeze and objective measures of allergy in both affluent and nonaffluent countries. In contrast, breastfeeding was associated with higher predicted forced expiratory volume in one second in affluent countries only (mean ratio 1.11, 95% CI 1.02-1.20). Breastfeeding is associated with protection against nonatopic wheeze, which becomes particularly evident in nonaffluent countries. Overall, breastfeeding was not related to any measure of allergy. These findings may explain some of the controversy regarding breastfeeding, since the direction of the association with breastfeeding depends on the predominating wheeze phenotype (e.g. atopic, nonatopic).European Respiratory Journal 02/2009; 33(5):993-1002. · 5.89 Impact Factor -
Article: Asthma and allergic symptoms in relation to house dust endotoxin: Phase Two of the International Study on Asthma and Allergies in Childhood (ISAAC II).
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ABSTRACT: Several studies have consistently reported inverse associations between exposure to endotoxin in house dust and atopy. With regard to the association between house dust endotoxin and asthma, the results are inconsistent. To study the association between house dust endotoxin levels and respiratory symptoms and atopy in populations from largely different countries. Data were collected within the International Study on Asthma and Allergies in Childhood Phase Two, a multi-centre cross-sectional study of 840 children aged 9-12 years from six centres in the five countries of Albania, Italy, New Zealand, Sweden and the United Kingdom. Living room floor dust was collected and analysed for endotoxin. Health end-points and demographics were assessed by standardized questionnaires. Atopy was assessed by measurements of allergen-specific IgE against a panel of inhalant allergens. Associations between house dust endotoxin and health outcomes were analysed by logistic regression. Odds ratios (ORs) were presented for an overall interquartile range increase in exposure. Many associations between house dust endotoxin in living room floor dust and health outcomes varied between countries. Combined across countries, endotoxin levels were inversely associated with asthma ever [adjusted OR (95% confidence interval (CI)) 0.53 (0.29-0.96) for endotoxin levels per m(2) of living room floor] and current wheeze [adjusted OR (95% CI) 0.77 (0.64-0.93) for endotoxin levels per gram of living room floor dust]. There were inverse associations between endotoxin concentrations and atopy, which were statistically significant in unadjusted analyses, but not after adjustment for gender, parental allergies, cat and house dust mite allergens. No associations were found with dust quantity and between endotoxin exposure and hayfever. These findings suggest an inverse association between endotoxin levels in living room floor dust and asthma in children.Clinical & Experimental Allergy 10/2008; 38(12):1911-20. · 5.03 Impact Factor -
Article: International variation in prevalence of rhinitis and its relationship with sensitisation to perennial and seasonal allergens.
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ABSTRACT: The relative importance of atopy in the aetiology of rhinitis is largely unknown. The present study investigated the geographical variations in rhinitis in relation to atopy. The cross-sectional study involved 54,178 children (aged 8-12 yrs) from 30 study centres in 22 countries worldwide. Symptoms of rhinoconjunctivitis and rhinitis without conjunctivitis in the last 12 months were reported in parental questionnaires and children were skin-prick tested. The prevalence of rhinoconjunctivitis and rhinitis without conjunctivitis varied widely (1.5-24.5% and 1.4-45.2%, respectively). For rhinoconjunctivitis, the population attributable fraction (PAF) varied 0-71% for a positive skin-prick test to one or more seasonal allergens and 0-41% for perennial allergens. The PAF for sensitisation to seasonal and perennial allergens was higher in affluent countries (36 and 25%, respectively) than nonaffluent countries (1.3 and 12.6%, respectively). For rhinitis without conjunctivitis, the PAF for perennial allergens was 8 and 4% for affluent and nonaffluent countries, respectively. No significant PAF was found for seasonal allergens. Overall, atopy explained only a limited proportion of rhinitis symptoms, suggesting that the importance of other environmental factors has been under emphasised, particularly in less affluent countries. Atopy seems to be only marginally relevant for rhinitis without conjunctivitis, which seems mainly to reflect nonatopic rhinitis.European Respiratory Journal 07/2008; 32(5):1250-61. · 5.89 Impact Factor -
Article: Leisure time activity and new onset of wheezing during adolescence.
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ABSTRACT: Asthma prevalence is increasing in adult and paediatric patients. In the present study, the association between different leisure time activities and new onset of wheezing was analysed in adolescents aged 16-18 yrs taking part in a questionnaire-based follow-up of the International Study on Asthma and Allergies in Childhood in Munich and Dresden, Germany. Of the 3,785 adolescents who took part in the follow-up (76% response), 2,910 adolescents without earlier episodes of wheezing in childhood were included in the analyses. Of these, 330 (11.3%) reported new onset of wheeze during the previous 12 months. In the bivariate analyses, exercising more than once per week or performing computer work >1 h.day(-1) were inversely related to new onset of wheeze. In contrast, visiting discotheques on a regular basis increased the risk of new onset of wheeze (12.9 versus 9.9%). The observed inverse relationship between physical activity and new onset of wheeze was not an independent effect but mediated by differences in active smoking. The association between physical activity and new onset of wheeze disappeared when active smoking was taken into account. However, the present data do not allow for determining whether smoking operated as a confounder or as an intermediate factor, i.e. whether physical activities prevented active smoking.European Respiratory Journal 10/2007; 30(4):672-6. · 5.89 Impact Factor -
Article: First months of employment and new onset of rhinitis in adolescents.
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ABSTRACT: The aim of the present study was to investigate the incidence of rhinitis in adolescents, taking into account the duration and type of employment in holiday and vocational jobs, and to study latency until development of symptoms. Participants of the International Study of Asthma and Allergies in Childhood (ISAAC)-II study in Munich and Dresden (Germany), who were enrolled in 1995, were re-contacted by a postal questionnaire in 2002 (aged 16-18 yrs). The questionnaire focused on allergic rhinitis, type and duration of all jobs, and potential confounders. All jobs held for >/=8 h.week(-1) and >/=1 month were coded and occupational exposure was assigned by a job-exposure matrix. Out of the 3,785 participants, 964 reported an employment history. The median (25th-75th percentile) duration of employment was 10 (1-16) months. After adjusting for potential confounders, those working in high-risk occupations (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.0-2.1) had an increased risk for new onset of rhinitis, especially those exposed to low molecular weight agents (OR 1.8, 95% CI 1.1-2.8). The incidence of rhinitis was highest among those currently employed in a high-risk job for <10 months. Teenagers who start working in high-risk occupations have a higher incidence of rhinitis compared with those not working. This increased risk might occur early on during employment.European Respiratory Journal 09/2007; 30(3):549-55. · 5.89 Impact Factor -
Article: Smoking and the incidence of asthma during adolescence: results of a large cohort study in Germany.
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ABSTRACT: The association between smoking and asthma or wheeze has been extensively studied in cross sectional studies, but evidence from large prospective cohort studies on the incidence of asthma during adolescence is scarce. We report data from a cohort study in two German cities, Dresden and Munich. The study population (n = 2936) was first studied in 1995/6 at age 9-11 years as part of phase II of the International Study of Asthma and Allergies in Childhood (ISAAC II) and followed up in 2002/3. At baseline the parents completed a questionnaire and children underwent clinical examination and blood sampling. At follow up the young adults completed questionnaires on respiratory health, living, and exposure conditions. Incidence risk ratios (IRR) were calculated and adjusted for potential confounders using a modified Poisson regression approach. The adjusted IRR for incident wheeze for active smokers compared with non-smokers was 2.30 (95% confidence interval (CI) 1.88 to 2.82). The adjusted IRR was slightly higher for incident wheeze without a cold (2.76, 95% CI 1.99 to 3.84) and the incidence of diagnosed asthma (2.56, 95% CI 1.55 to 4.21). Analysis of duration and intensity of active smoking indicated dose dependent associations. Stratified analyses showed that the risk of incident wheeze without a cold in atopic smokers increased with decreasing plasma alpha(1)-antitrypsin levels at baseline (1.64, 95% CI 1.22 to 2.20 per interquartile range). Active smoking is an important risk factor for the incidence of asthma during adolescence. Relatively lower plasma levels of alpha(1)-antitrypsin, although well above currently accepted thresholds, may increase susceptibility to respiratory disease among atopic smokers.Thorax 08/2006; 61(7):572-8. · 6.84 Impact Factor -
Article: Do respiratory symptoms predict job choices in teenagers?
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ABSTRACT: Existing guidelines advise adolescents with asthma and allergies against high-risk occupations. The aim of the current authors' analyses was to investigate the resulting self-selection in a prospective cohort study. The participants of Phase II of the International Study of Asthma and Allergies in Childhood in Germany (aged 9-11 yrs at baseline) were re-contacted after 7 yrs (response rate was 77%) and were asked to complete a questionnaire, which included items on atopic diseases. The subjects were also asked about the type of job they would like to have in the future (preferred job choice). Exposure to agents with potential asthma risk was evaluated using a job exposure matrix. The analyses were restricted to those in school-based vocational training programmes without occupational exposures. A total of 33% of subjects chose jobs with high asthma risk, 23% selected low asthma risk jobs and the remaining adolescents indicated jobs without known asthma risk (reference category). There were no statistically significant associations between asthma, allergic rhinitis or atopic dermatitis and selecting jobs with asthma risk. Participants with allergic rhinitis tended to select high risk jobs less frequently. In conclusion, self-selection into low risk jobs seems to play a minor role in teenagers with asthma or allergies.European Respiratory Journal 05/2006; 27(4):774-8. · 5.89 Impact Factor -
Article: Atopic sensitization and the international variation of asthma symptom prevalence in children
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Article: International variation in prevalence of rhinitis and its relationship with sensitisation to perennial and seasonal allergens.
[show abstract] [hide abstract]
ABSTRACT: The relative importance of atopy in the aetiology of rhinitis is largely unknown. The present study investigated the geographical variations in rhinitis in relation to atopy. The cross-sectional study involved 54,178 children (aged 8-12 yrs) from 30 study centres in 22 countries worldwide. Symptoms of rhinoconjunctivitis and rhinitis without conjunctivitis in the last 12 months were reported in parental questionnaires and children were skin-prick tested. The prevalence of rhinoconjunctivitis and rhinitis without conjunctivitis varied widely (1.5-24.5% and 1.4-45.2%, respectively). For rhinoconjunctivitis, the population attributable fraction (PAF) varied 0-71% for a positive skin-prick test to one or more seasonal allergens and 0-41% for perennial allergens. The PAF for sensitisation to seasonal and perennial allergens was higher in affluent countries (36 and 25%, respectively) than nonaffluent countries (1.3 and 12.6%, respectively). For rhinitis without conjunctivitis, the PAF for perennial allergens was 8 and 4% for affluent and nonaffluent countries, respectively. No significant PAF was found for seasonal allergens. Overall, atopy explained only a limited proportion of rhinitis symptoms, suggesting that the importance of other environmental factors has been under emphasised, particularly in less affluent countries. Atopy seems to be only marginally relevant for rhinitis without conjunctivitis, which seems mainly to reflect nonatopic rhinitis.
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2008–2013
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Universität Ulm
- Institute of Epidemiology and Medical Biometry
Ulm, Baden-Wuerttemberg, Germany
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