http://repub.eur.nl/res/aut/4134/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/40179/ 2013-04-29T00:00:00Z A common policy response to the rise in obesity prevalence is to undertake interventions in childhood, but it is an open question whether this is more effective than reducing the risk of becoming obese during adulthood. In this paper, we model the effect on health outcomes of (i) reducing the prevalence of obesity when entering adulthood; (ii) reducing the risk of becoming obese throughout adult life; and (iii) combinations of both approaches. We found that, while all approaches reduce the prevalence of chronic diseases and improve life expectancy, a given percentage reduction in obesity prevalence achieved during childhood had a smaller effect than the same percentage reduction in the risk of becoming obese applied throughout adulthood. A small increase in the probability of becoming obese during adulthood offsets a substantial reduction in prevalence of overweight/obesity achieved during childhood, with the gains from a 50% reduction in child obesity prevalence offset by a 10% increase in the probability of becoming obese in adulthood. We conclude that both policy approaches can improve the health profile throughout the life course of a cohort, but they are not equivalent, and a large reduction in child obesity prevalence may be reversed by a small increase in the risk of becoming overweight or obese in adulthood. http://repub.eur.nl/res/pub/39624/ 2013-04-01T00:00:00Z http://repub.eur.nl/res/pub/38889/ 2012-11-20T00:00:00Z In Health Impact Assessment (HIA), or priority-setting for health policy, effects of risk factors (exposures) on health need to be modeled, such as with a Markov model, in which exposure influences mortality and disease incidence rates. Because many risk factors are related to a variety of chronic diseases, these Markov models potentially contain a large number of states (risk factor and disease combinations), providing a challenge both technically (keeping down execution time and memory use) and practically (estimating the model parameters and retaining transparency). To meet this challenge, we propose an approach that combines micro-simulation of the exposure information with macro-simulation of the diseases and survival. This approach allows users to simulate exposure in detail while avoiding the need for large simulated populations because of the relative rareness of chronic disease events. Further efficiency is gained by splitting the disease state space into smaller spaces, each of which contains a cluster of diseases that is independent of the other clusters. The challenge of feasible input data requirements is met by including parameter calculation routines, which use marginal population data to estimate the transitions between states. As an illustration, we present the recently developed model DYNAMO-HIA (DYNAMIC MODEL for Health Impact Assessment) that implements this approach. http://repub.eur.nl/res/pub/37398/ 2012-10-01T00:00:00Z Breastfed individuals have a lower blood pressure than formula-fed individuals. Supplementation with n-3 long-chain polyunsaturated fatty acids in adults is also associated with a lower blood pressure. We studied whether children receiving human milk with a relatively high content of n-3 long-chain polyunsaturated fatty acids have a lower blood pressure at age 12 years, and, if so, whether this association is explained by the n-3 long-chain polyunsaturated fatty acids content in erythrocyte membranes at age 12 years. Within a 12-year follow-up of a population-based birth cohort, we compared blood pressure of 205 never-breastfed children and 109 children who had fatty acid composition of their mothers' breast milk measured during lactation. In addition, 973 children had information on erythrocyte fatty acid composition and blood pressure at age 12 years. Children who received human milk with an n-3 long-chain polyunsaturated fatty acids content above the median (ie, 0.51 weight percentage) had a 4.79-mm Hg lower systolic (95% CI, -7.64 to -1.94) and a 2.47-mm Hg lower diastolic (95% CI, -4.45 to -0.49) blood pressure at age 12 years than never-breastfed children. N-3 long-chain polyunsaturated fatty acids levels in human milk below the median value and current n-3 long-chain polyunsaturated fatty acid status were not associated with blood pressure at age 12 years. Thus, a relatively high content of n-3 long-chain polyunsaturated fatty acids in human milk is associated with a lower blood pressure in children at age 12 years, a finding not explained by current n-3 long-chain polyunsaturated fatty acids status. http://repub.eur.nl/res/pub/37723/ 2012-09-01T00:00:00Z Objective: Western Europe has high levels of alcohol consumption, with corresponding adverse health effects. Currently, a major revision of the EU excise tax regime is under discussion. We quantify the health impact of alcohol price increases across the EU. Data and method: We use alcohol consumption data for 11 member states, covering 80% of the EU-27 population, and corresponding country-specific disease data (incidence, prevalence, and case-fatality rate of alcohol related diseases) taken from the 2010 published Dynamic Modelling for Health Impact Assessment (DYNAMO-HIA) database to dynamically project the changes in population health that might arise from changes in alcohol price. Results: Increasing alcohol prices towards those of Finland (the highest in the EU) would postpone approximately 54,000 male and approximately 26,100 female deaths over 10. years. Moreover, the prevalence of a number of chronic diseases would be reduced: in men by approximately 97,800 individuals with diabetes, 65,800 with stroke and 62,200 with selected cancers, and in women by about 19,100, 23,500, and 27,100, respectively. Conclusion: Curbing excessive drinking throughout the EU completely would lead to substantial gains in population health. Harmonisiation of prices to the Finnish level would, for selected diseases, achieve more than 40% of those gains. http://repub.eur.nl/res/pub/31999/ 2012-01-01T00:00:00Z http://repub.eur.nl/res/pub/34786/ 2012-01-01T00:00:00Z Background Systemic inflammation is suggested as a mechanism by which overweight might induce asthma. However, few studies have linked childhood overweight, inflammation and asthma. Objective To study the association between body mass index (BMI), asthma symptoms and pro-inflammatory proteins. Methods High-sensitivity C-reactive protein (hs-CRP), complement factor 3 (C3) and 4 (C4) concentrations, and body weight and height were available for 359 4-year-old children participating in the Prevention and Incidence of Asthma and Mite Allergy birth cohort study. Data on asthma symptoms were obtained by yearly questionnaires. Logistic regression and generalized estimating equations were used to analyse the cross-sectional and prospective associations between BMI, asthma symptoms and pro-inflammatory proteins. Results BMI was associated with asthma symptoms {odds ratio [OR] 1.43 [95% confidence interval (CI): 1.08-1.88] per BMI standard deviation scores [SDS]}. The inclusion of hs-CRP, C3 and C4 in the statistical models did not change this association. C3 was cross-sectionally associated with frequent asthma symptoms [OR per interquartile range of C3: 1.97 (95% CI: 1.20-3.24)] and prospectively with asthma symptoms [OR: 1.48 (95%CI: 1.04-2.09)], independent of BMI SDS. Conclusions and Clinical Relevance We showed no evidence for a role of hs-CRP, C3 and C4 in the association between BMI and asthma symptoms. C3 concentrations were associated with (frequent) asthma symptoms, independent of BMI. http://repub.eur.nl/res/pub/21604/ 2010-11-01T00:00:00Z Purpose: This study was conducted to assess the validity of parental reported use of inhaled corticosteroids (ICS) in children. Methods: ICS users were identified within the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study and the PIAMA pharmacy sub-cohort which is nested within the PIAMA study. Complete medication histories were available for the first 8 years of life for children within the PIAMA pharmacy sub-cohort. Parental reported ICS use was measured by using data from questionnaires. ICS use in the pharmacy records was determined by using the Anatomical Therapeutic Chemical (ATC) codes. The proportion of overall agreement and kappa statistics with their corresponding 95% confidence intervals were calculated to quantify agreement between self-reported medication use and pharmacy prescription data. Results: At all ages overall agreement was very high (>97%) and Cohen's kappa's ranged from 0.80 to 0.88 which also reflects excellent agreement between parental reported use of ICS and pharmacy prescription data. Conclusions: Our finding suggests that parental report of medication use is a reliable source of data to asses ICS use in children. The questionnaire-based medication data collected within the PIAMA study can be used to study asthma medication use in a large group of children. http://repub.eur.nl/res/pub/20320/ 2010-06-01T00:00:00Z Background: Exposure to environmental tobacco smoke (ETS) is known to increase the risk of respiratory tract infections (RTI). Some children, however, may be more susceptible to the harmful effects of ETS than others. We examined whether early atopic status (defi ned by elevated neonatal total IgE (tIgE) or symptoms of atopic dermatitis) modifi ed the association between ETS exposure and RTI. Methods: The data of 2863 children from the Prevention and Incidence of Asthma and Mite Allergy birth cohort were collected to the age of 4 years. Neonatal tIgE was collected from a subset of 914 children, and clinical information by yearly parental questionnaires. The effect of pre- and/or postnatal ETS exposure, early atopic status and interaction between these factors was studied for various RTI. Results: Children with elevated tIgE or atopic dermatitis and prenatal ETS exposure have a strongly increased risk of frequent RTI (aOR 6.18 (95% CI 1.45 to 26.34) and 5.69 (2.01 to 16.04), respectively; interaction p=0.006 and p=0.14, respectively) compared to non-atopic children without prenatal ETS exposure. Similar results were seen for lower RTI and otitis. This effect was less evident for postnatal ETS. Conclusion: Early atopic status enhances the risk of RTI in children with prenatal ETS exposure. This suggests that host factors modify the association between ETS and RTI. http://repub.eur.nl/res/pub/28497/ 2010-04-15T00:00:00Z Background. There is ample evidence that childhood overweight is associated with increased risk of chronic disease in adulthood. The aim of this study was to investigate associations between childhood overweight and common childhood health problems. Methods. Data were used from a general population sample of 3960 8-year-old children, participating in the Dutch PIAMA birth cohort study. Weight and height, measured by the investigators, were used to define BMI status (thinness, normal weight, moderate overweight, obesity). BMI status was studied cross-sectionally in relation to the following parental reported outcomes: a general health index, GP visits, school absenteeism due to illness, health-related functional limitations, doctor diagnosed respiratory infections and use of antibiotics. Results. Obesity was significantly associated with a lower general health score, more GP visits, more school absenteeism and more health-related limitations, (adjusted odds ratios around 2.0 for most outcomes). Obesity was also significantly associated with bronchitis (adjusted odds ratio (aOR) and 95% confidence intervals (95%CI): 5.29 (2.58;10.85) and with the use of antibiotics (aOR (95%CI): 1.79 (1.09;2.93)). Associations with flu/serious cold, ear infection and throat infection were positive, but not statistically significant. Moderate overweight was not significantly associated with the health outcomes studied. Conclusion. Childhood obesity is not merely a risk factor for disease in adulthood, but obese children may experience more illness and health related problems already in childhood. The high prevalence of the outcomes studied implies a high burden of disease in terms of absolute numbers of sick children. http://repub.eur.nl/res/pub/27901/ 2010-04-01T00:00:00Z Objective:The aim of this study was to investigate the association between maternal overweight before pregnancy and offspring asthma in an ongoing birth cohort study. Maternal overweight may affect the pulmonary and immunological development of the fetus in utero because of the increased levels of inflammatory factors associated with being overweight and thereby increase the asthma risk in childhood.Design:Birth cohort study with follow-up until 8 years of age.Subjects:The study population included 3963 children and their mothers who participated in the Prevention and Incidence of Asthma and Mite Allergy study.Measurements:Maternal overweight before pregnancy was defined as a body mass index (BMI) above 25 kg m 2. Data on wheeze, dyspnea and prescription of inhaled corticosteroids of the child were reported yearly by the parents in a questionnaire. Sensitization to inhalant allergens and bronchial hyperresponsiveness (BHR) were determined at 8 years. Effect modification by predisposition for asthma in the child was tested. Data were analyzed by logistic regression and generalized estimating equations analyses.Results:At 8 years, 14.4% (n571) of the children had asthma. In total, 20.9% (n830) of the mothers were overweight before pregnancy. In children predisposed for asthma (n1058), maternal overweight before pregnancy was associated with an increased risk of asthma in the child at 8 years (OR1.52, 95% CI: 1.05-2.18) after adjustment for confounding factors, birth weight and the child's BMI. No association was observed in children without a predisposition (OR0.86, 95% CI: 0.60-1.23). There was no association with sensitization or BHR.Conclusion: Children with a predisposition for asthma may have a higher risk to develop asthma during childhood when their mothers are overweight before pregnancy, irrespective of the child's BMI. http://repub.eur.nl/res/pub/32732/ 2010-03-15T00:00:00Z Rationale: The role of air pollution exposure in the development of asthma, allergies,andrelatedsymptomsremains unclear,duein part to the limited number of prospective cohort studies with sufficiently long follow-ups addressing this problem. Objectives: We studied the association between traffic-related air pollution and the development of asthma, allergy, and related symptoms in a prospective birth cohort study with a unique 8-year follow-up. Methods: Annual questionnaire reports of asthma, hay fever, and related symptoms during the first 8 years of life were analyzed for 3,863 children. At age 8, measurements of allergic sensitization and bronchial hyperresponsiveness were performed for subpopulations (n = 1,700 and 936, respectively). Individual exposures to nitrogen dioxide (NO2), particulate matter (PM2.5), and soot at the birth address were estimated by land-use regression models. Associations between exposure to traffic-related air pollution and repeated measures of health outcomes were assessed by repeated-measures logistic regression analysis. Effects are presented for an interquartile range increase in exposure after adjusting for covariates. Measurements and Main Results: Annual prevalence was 3 to 6% for asthma and 12 to 23% for asthma symptoms. Annual incidence of asthma was 6%at age 1, and 1 to 2%at later ages. PM2.5levels were associated with a significant increase in incidence of asthma (odds ratio [OR], 1.28;95%confidenceinterval [CI], 1.10-1.49), prevalence of asthma (OR, 1.26; 95% CI, 1.04-1.51), and prevalence of asthma symptoms (OR, 1.15; 95% CI, 1.02-1.28). Findings were similar for NO2 and soot. Associations were stronger for children who had not moved since birth. Positive associations with hay fever were found in nonmovers only. No associations were found with atopic eczema, allergic sensitization, and bronchial hyperresponsiveness. Conclusions: Exposure to traffic-related air pollution may cause asthma in children. http://repub.eur.nl/res/pub/21430/ 2010-01-01T00:00:00Z Background: Maternal exposure to air pollution has been associated with adverse pregnancy outcomes. Few studies took into account the spatial and temporal variation of air pollution levels. Objectives: To evaluate the impact of maternal exposure to traffic-related air pollution during pregnancy on preterm birth and term birth weight using a spatio-temporal exposure model. Methods: We estimated maternal residential exposure to nitrogen dioxide (NO2), particulate matter (PM2.5) and soot during pregnancy (entire pregnancy, 1st trimester, and last month) for 3853 singleton births within the Dutch PIAMA prospective birth cohort study by means of temporally adjusted land-use regression models. Associations between air pollution concentrations and preterm birth and term birth weight were analyzed by means of logistic and linear regression models with and without adjustment for maternal physical, lifestyle, and socio-demographic characteristics. Results: We found positive, statistically non-significant associations between exposure to soot during entire pregnancy and during the last month of pregnancy and preterm birth [adj. OR (95% CI) per interquartile range increase in exposure 1.08 (0.88-1.34) and 1.09 (0.93-1.27), respectively]. There was no indication of an adverse effect of air pollution exposure on term birth weight. Conclusions: In this study, maternal exposure to traffic-related air pollution during pregnancy was not associated with term birth weight. There was a tendency towards an increased risk of preterm birth with increasing air pollution exposure, but statistical power was low. http://repub.eur.nl/res/pub/21795/ 2010-01-01T00:00:00Z http://repub.eur.nl/res/pub/16304/ 2009-06-01T00:00:00Z Introduction: ADAM33 is the first identified asthma gene by positional cloning, especially asthma combined with bronchial hyperresponsiveness (BHR). Moreover, ADAM33 is associated with early-life lung function and decline of forced expiratory volume in 1 s (FEV1) in the general population. In utero and postnatal cigarette smoke exposure (CSE) are associated with reduced lung function, and development of BHR and asthma. We hypothesized that this may occur via interaction with ADAM33. Aim: To replicate the role of ADAM33 in childhood lung function and development of BHR and asthma. Furthermore, we investigated gene-environment interaction of ADAM33 with in utero and postnatal CSE in the Dutch PIAMA cohort. Methods: Six ADAM33 single-nucleotide polymorphisms (SNPs) were genotyped. Rint was measured at age 4 and 8 years, FEV1 and BHR at age 8 years; asthma was based on questionnaire data at age 8. Results: In the total cohort, the rs511898 A, rs528557 C, and rs2280090 A alleles increased the risk to develop asthma (+BHR). There existed interaction between in utero but not postnatal CSE and the rs528557 and rs3918396 SNPs with respect to development of BHR, the rs3918396 SNP with Rint at age 8 and the rs528557 SNP with FEV1% predicted. Conclusions: We confirm associations between ADAM33 and the development of asthma (+BHR). This is the first study suggesting that interaction of in utero CSE with ADAM33 results in reduced lung function and the development of BHR, which needs further confirmation. http://repub.eur.nl/res/pub/25401/ 2009-04-01T00:00:00Z OBJECTIVE. Studies among patients have shown accelerated weight gain after (adeno)tonsillectomy.* Whether (adeno)tonsillectomy is also a risk factor for the development of overweight is unknown. We investigated the association between (adeno)tonsillectomy and the subsequent development of overweight in the general population. METHODS. The study population consisted of 3963 children participating in the Dutch Prevention and Incidence of Asthma and Mite Allergy birth cohort. Data on weight and height, adenoidectomy and tonsillectomy, and covariates (gender, birth weight, maternal education, maternal overweight, maternal smoking during pregnancy, breastfeeding, and smoking in the home) were obtained from annual questionnaires completed by the parents. In addition to the questionnaire data, weight and height were measured by the investigators when the children were 8 years old. RESULTS. (Adeno)tonsillectomy between 0 and 7 years of age was significantly associated with overweight and obesity at age 8. Overweight at the age of 2 years was not associated with increased risk of (adeno)tonsillectomy in later years, indicating that the association between (adeno)tonsillectomy and overweight was not explained by preexisting overweight. Longitudinal data on weight and height in the years before and after surgery suggest that (adeno)tonsillectomy forms a turning point between a period of growth faltering and a period of catch-up growth, which might explain the increased risk to develop overweight after the operation. CONCLUSION. Children who undergo (adeno)tonsillectomy are at increased risk to develop overweight in the years after surgery. Copyright http://repub.eur.nl/res/pub/14422/ 2008-11-01T00:00:00Z Breastfeeding has been associated with a reduced risk of overweight later in life. This study investigates whether differences in diet and lifestyle at 7 years of age between breastfed and formula-fed children can explain the difference in overweight prevalence at 8 years of age. We studied 2,043 Dutch children born in 1996-1997 who participated in the Prevention and Incidence of Asthma and Mite Allergy birth cohort study. Data on breastfeeding duration and diet and lifestyle factors at 7 years were collected using questionnaires. Weight and height were measured at 8 years. Overweight was defined according to international gender- and age-specific standards. Compared to nonbreastfed children (15.5%, n = 316), children breastfed for >16 weeks (38.0%, n = 776) consumed fruit and vegetables significantly more often and meat, white bread, carbonated soft drinks, chocolate bars, and fried snacks less often. Overall, breastfed children were less likely to have an unhealthy diet (adjusted prevalence ratio: 0.77, 95% confidence interval: 0.61-0.98). The associations could only partly be explained by maternal education, maternal overweight, and smoking during pregnancy. At 8 years, 14.5% (n = 297) of the children were overweight. Breastfeeding for >16 weeks was significantly associated with a lower overweight risk at 8 years (adjusted odds ratio: 0.67, 95% confidence interval: 0.47-0.97), and the association hardly changed after adjustment for diet (adjusted odds ratio: 0.71, 95% confidence interval: 0.49-1.03). Breastfed children had a healthier diet at 7 years compared to nonbreastfed children, but this difference could not explain the lower overweight risk at 8 years in breastfed children. © 2008 The Obesity Society. http://repub.eur.nl/res/pub/15937/ 2008-10-01T00:00:00Z Objective: In young children with asthmatic symptoms diagnostic difficulties lead to use of trials of asthma medication as a diagnostic tool. Our aim is to quantify the persistent use of asthma medication, initiated in the first year of life and identify determinants of this persistent use. Patients and methods: We identified 165 children within the PIAMA (Prevention and Incidence of Asthma and Mite Allergy) birth cohort who used asthma medication before the age of one. Persistent use was investigated during three years after the first prescription. A Cox regression analysis was performed to identify factors associated with persistent use. Results: A total of 58.8% of children continued using asthma medication after the first prescription and 10.3% continued during three years. Children with doctor-diagnosed asthma (Hazard ratio of discontinuation (HR) = 0.64, 95% CI: 0.45-0.91) or prescribed inhaled corticosteroids in the first year of life (HR of discontinuation = 0.59, 95% CI: 0.40-0.86) were 1.6-1.7 times more likely to continue using asthma medication. Conclusions: Persistence of asthma medication, prescribed in the first year of life is very low and is positively associated with doctor-diagnosed asthma and use of inhaled corticosteroids. Characterizing persistent users of asthma medication is important to understand prescribing of asthma medication in this age group. http://repub.eur.nl/res/pub/32502/ 2008-07-15T00:00:00Z Rationale: Maternal diet during pregnancy has the potentialto affect airway development and to promote T-helper-2-cell responses during fetal life. This might increase the riskofdeveloping childhood asthma or allergy. Objectives:We investigated the influence of maternal food consumption during pregnancy on childhood asthma outcomes from 1 to 8 years of age. Methods: A birth cohort study consisting of a baseline of 4,146 pregnant women(1,327 atopic and 2,819nonatopic).These women were asked about their frequency of consumption of fruit, vegeta-bles, fish, egg, milk, milk products, nuts, and nut products during the last month. Their children were followed until 8 years of age. Longitudinal analyses were conducted to assess associations between maternal diet during pregnancy and childhood asthma outcomes over 8 years. Measurements and Main Results: Complete data were obtained for 2,832 children. There were no associations between maternal vegetable, fish, egg, milk or milk products, and nut consumption and longitudinal childhood outcomes. Daily consumptionofnut products increased the risk of childhood wheeze (odds ratio [OR] daily versus rare consumption, 1.42; 95% confidence interval [95% CI], 1.06-1.89), dyspnea (OR, 1.58; 95% CI, 1.16-2.15), steroid use (OR, 1.62; 95% CI, 1.06-2.46), and asthma symptoms (OR, 1.47; 95% CI, 1.08-1.99). Conclusions: Results of this study indicate an increased risk of daily versus rare consumption of nut products during pregnancy on child-hood asthma outcomes.These findings need to be replicated by other studies before dietary advice can be given to pregnant women. http://repub.eur.nl/res/pub/30376/ 2008-02-26T00:00:00Z Background. In pre-school children a diagnosis of asthma is not easily made and only a minority of wheezing children will develop persistent atopic asthma. According to the general consensus a diagnosis of asthma becomes more certain with increasing age. Therefore the congruence between asthma medication use and doctor-diagnosed asthma is expected to increase with age. The aim of this study is to evaluate the relationship between prescribing of asthma medication and doctor-diagnosed asthma in children age 0-17. Methods. We studied all 74,580 children below 18 years of age, belonging to 95 GP practices within the second Dutch national survey of general practice (DNSGP-2), in which GPs registered all physician-patient contacts during the year 2001. Status on prescribing of asthma medication (at least one prescription for beta2-agonists, inhaled corticosteroids, cromones or montelukast) and doctor-diagnosed asthma (coded according to the International Classification of Primary Care) was determined. Results. In total 7.5% of children received asthma medication and 4.1% had a diagnosis of asthma. Only 49% of all children receiving asthma medication was diagnosed as an asthmatic. Subgroup analyses on age, gender and therapy groups showed that the Positive Predictive Value (PPV) differs significantly between therapy groups only. The likelihood of having doctor-diagnosed asthma increased when a child received combination therapy of short acting beta2-agonists and inhaled corticosteroids (PPV = 0.64) and with the number of prescriptions (3 prescriptions or more, PPV = 0.66). Both prescribing of asthma medication and doctor-diagnosed asthma declined with age but the congruence between the two measures did not increase with age. Conclusion. In this study, less than half of all children receiving asthma medication had a registered diagnosis of asthma. Detailed subgroup analyses show that a diagnosis of asthma was present in at most 66%, even in groups of children treated intensively with asthma medication. Although age strongly influences the chance of being treated, remarkably, the congruence between prescribing of asthma medication and doctor-diagnosed asthma does not increase with age. http://repub.eur.nl/res/pub/36734/ 2007-08-01T00:00:00Z Background: In adults, body weight tends to be underestimated when based on self-reported data. Whether this discrepancy between measured and reported data exists in healthy young children is unclear. We studied whether parental reported body weight and height of 4-year-old children corresponded with measured body weight and height. In addition, we studied the determinants and the consequences of differences between reported and measured data. Methods: Data on body weight and height of 864 4-year-old Dutch children born in 1996/1997 enrolled in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study were collected via a questionnaire and a medical examination. Overweight was defined according to standard international age and gender specific definitions. Results: Mean differences between measured and reported body weight, height, and body mass index (BMI) were small. Parents of children with a low BMI tended to over report body weight while parents of children with a high BMI tended to underreport body weight. Whereas 9.5% of the children were overweight according to reported BMI, the prevalence of overweight was 13.4% based on measured BMI. Over 45% of the overweight children according to measured BMI were missed when reported BMI was used. Conclusion: These findings suggest that overweight prevalence rates in children are underestimated when based on reported weight and height. http://repub.eur.nl/res/pub/36893/ 2007-07-06T00:00:00Z Background. A higher prevalence of respiratory symptoms and an associated increase in health care utilization among children with parents who smoke is to be expected. From previous studies however, it appears that parents who smoke may underutilize health services for their children, especially with respect to respiratory care. This study explores the validity and generalizability of the previous assumption. Methods. Data were obtained from a Dutch birth-cohort study; the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) project. Information regarding parental smoking, the child's respiratory symptoms and health care use and potential confounders were obtained by postal questionnaires. Multivariate logistic models were used to relate parental smoking to the child's respiratory symptoms and health care use. Results. The study comprised 3,564, 4-year old children. In the crude analysis, respiratory symptoms were more frequent among children with a parent who smoked, while health care utilization for respiratory symptoms was not significantly different between children with or without a parent who smoked. In the multivariate analyses, maternal smoking had a larger impact on the child's respiratory symptoms and health care use as compared to paternal smoking. Maternal smoking was positively associated with mild respiratory symptoms of the child, adjusted odds ratio [AOR] 1.50 (1.19-1.91), but not with severe respiratory symptoms AOR 1.03 (0.75-1.40). Among children with mild respiratory symptoms, children with a mother who smoked were less likely to be taken to the general practitioner (GP) for respiratory symptoms, than children with mothers who did not smoke, AOR 0.58 (0.33-1.01). This finding was less pronounced among children with severe respiratory symptoms AOR 0.86 (0.49-1.52). Neither GP visits for non-respiratory symptoms nor specialized care for respiratory disease were significantly associated with parental smoking. Conclusion. Mothers who smoke appear to underutilize health care for their children with mild respiratory symptoms. Health care workers should be informed about this phenomenon. Inquiring after the respiratory health of the children during regular visits to healthy baby clinics may help to track potential underutilization of care. http://repub.eur.nl/res/pub/36453/ 2007-06-01T00:00:00Z It has been suggested that early childhood exposure to microbial agents decreases the risk of allergies in children. The current authors studied the association between microbial agents in house dust and allergic sensitisation in children aged 2-4 yrs. Nested case-control studies were performed within ongoing birth cohort studies in Germany, the Netherlands and Sweden and ∼180 sensitised and 180 nonsensitised children were selected per country. Levels of bacterial endotoxin, β(1,3)-glucans and fungal extracellular polysaccharides (EPS) were measured in dust samples from the children's mattresses and the living-room floors. Combined across countries, higher amounts of mattress dust and higher mattress dust loads of endotoxin, β(1,3)-glucans and EPS were associated with a significantly decreased risk of sensitisation to inhalant allergens. After mutual adjustment, only the protective effect of the amount of mattress dust remained significant (odds ratio (95% confidence interval) 0.57(0.39-0.84)). Higher amounts of mattress dust may decrease the risk of allergic sensitisation to inhalant allergens. The effect might be partly attributable to endotoxin, β(1,3)-glucans and extracellular polysaccharides, but could also reflect (additional) protective effects of (microbial) agents other than the ones measured. It is not possible to distinguish with certainty which component relates to the effect, since their levels are highly correlated. Copyright http://repub.eur.nl/res/pub/36645/ 2007-05-15T00:00:00Z Rationale: The relation between birth weight and respiratory symptoms and asthma in children remains unclear. Previous studies focused on a relation at separate ages. A longitudinal analysis may lead to a better understanding. Objectives: To estimate the effect of birth weight on the development and course of respiratory symptoms and asthma in the first 7 years of life. Methods: In a prospective birth cohort study, 3,628 children with a gestational age 37 weeks or more were monitored for 7 years. Parental questionnaires were used to assess respiratory health yearly. Associations of birth weight with respiratory symptoms (wheezing, coughing, respiratory infections) and doctor's diagnosis of asthma were assessed in a repeated-event analysis. Measurements and Main Results: Lower birth weight was associated with more respiratory symptoms (odds ratio [OR] per kg decrease in birth weight, 1.21; 95% confidence interval [CI], 1.09-1.34). The effect of birth weight increased from age 1 to 5, but decreased thereafter and was no longer significant at the age of 7. The effect of birth weight on respiratory symptoms was significantly greater among children exposed to tobacco smoke in their home than among nonexposed children (OR at 5 yr: 1.21 [95% CI, 1.02-1.44] and 1.52 [95% CI, 1.23-1.87], respectively). Birth weight and a doctor's diagnosis of asthma were not related (OR, 1.06; 95% CI, 0.82-1.37). Conclusions: A lower birth weight in children born at term is associated with a transiently increased risk of respiratory symptoms. This effect is enhanced by environmental tobacco smoke exposure. http://repub.eur.nl/res/pub/36471/ 2007-05-01T00:00:00Z Few studies have addressed associations between traffic-related air pollution and respiratory disease in young children. The present authors assessed the development of asthmatic/allergic symptoms and respiratory infections during the first 4 yrs of life in a birth cohort study (n=∼4,000). Outdoor concentrations of traffic-related air pollutants (nitrogen dioxide PM2.5, particles with a 50% cut-off aerodynamic diameter of 2.5 μm and soot) were assigned to birthplace home addresses with a land-use regression model. They were linked by logistic regression to questionnaire data on doctor-diagnosed asthma, bronchitis, influenza and eczema and to self-reported wheeze, dry night-time cough, ear/nose/ throat infections and skin rash. Total and specific immunoglobulin (Ig)E to common allergens were measured in a subgroup (n=713). Adjusted odds ratios (95% confidence intervals) per interquartile pollution range were elevated for wheeze (1.2 (1.0-1.4) for soot), doctor-diagnosed asthma (1.3 (1.0-1.7)), ear/nose/throat infections (1.2 (1.0-1.3)) and flu/serious colds (1.2 (1.0-1.4)). No consistent associations were observed for other end-points. Positive associations between air pollution and specific sensitisation to common food allergens (1.6 (1.2-2.2) for soot), but not total IgE, were found in the subgroup with IgE measurements. Traffic-related pollution was associated with, respiratory infections and some measures of asthma and allergy during the first 4 yrs of life. Copyright http://repub.eur.nl/res/pub/35501/ 2007-04-01T00:00:00Z Compared with nonbreastfed children, breastfed children tend to have a lower body mass index (BMI) at about 1 year of age. How the BMI of breastfed children develops after the first year when this difference in BMI at 1 year of age is considered is not clear. The authors studied the association between breastfeeding and BMI development from 1 to 7 years of age independently of BMI at 1 year of age. Longitudinal BMI data reported by parents of 2,347 Dutch children born in 1996-1997 who participated in the Prevention and Incidence of Asthma and Mite Allergy birth cohort study were collected. Linear regression and mixed-effects models were used for data analyses. Mean BMI at 1 year of age was 17.2 kg/m2(standard deviation, 1.4). Compared with nonbreastfed children, children breastfed for >16 weeks had a lower BMI at 1 year of age, after adjustment for confounders (β = -0.22, 95% confidence interval: -0.39, -0.06). The association between breastfeeding and BMI between 1 and 7 years of age was negligible, while a high BMI at 1 year of age was strongly associated with a high BMI between 1 and 7 years of age in the same model. These findings suggest that the lower BMI and lower risk of overweight among breastfed children later in life are already achieved at 1 year of age. Copyright http://repub.eur.nl/res/pub/8517/ 2002-01-01T00:00:00Z AIMS: To evaluate ethnic differences in the prevalence of respiratory and skin symptoms in the first two years of life. METHODS: A total of 4146 children participated in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Parents completed questionnaires on respiratory and skin symptoms, ethnic background, and other potential confounders during pregnancy, and at 3 months, 1 year, and 2 years of age. RESULTS: In the first year, "non-Dutch" children (compared with "Dutch" children) had a higher prevalence of runny nose with itchy/watery eyes (11.0% versus 5.0%). In the second year, a higher prevalence of wheeze at least once (26.7% versus 18.5%), night cough without a cold (24.6% versus 15.5%), runny nose without a cold (34.1% versus 21.3%), and runny nose with itchy/watery eyes (13.7% versus 4.6%) was found. Adjustment for various confounders, especially adjustment for socioeconomic factors, reduced most associations between ethnicity and respiratory symptoms. Only runny nose with itchy/watery eyes in the second year of life was independently associated with non-Dutch ethnicity (adjusted odds ratio 2.89, 95% CI 1.3-6.4). CONCLUSIONS: Non-Dutch children more often had respiratory symptoms in the first two years of life than Dutch children. This could largely be explained by differences in socioeconomic status. Follow up of the cohort will determine whether this higher prevalence of respiratory symptoms in children with non-Dutch ethnicity represents an increased risk of developing allergic disease rather than non-specific or infection related respiratory symptoms. http://repub.eur.nl/res/pub/9766/ 2001-01-01T00:00:00Z OBJECTIVE: To investigate the association between contacts with other children and the development of respiratory infections in the first year of life in children with or without genetic predisposition for allergy. METHODS: Children (n = 4146) who participate in a prospective birth cohort study (Prevention and Incidence of Asthma and Mite Allergy study) were investigated. Questionnaires were used to obtain information on doctor-diagnosed upper respiratory tract infection (URTI) and lower respiratory tract infection (LRTI), child care attendance, having siblings, family history of allergic disease, and various potential confounders. RESULTS: Child care attendance in the first year of life was associated with doctor-diagnosed URTI (adjusted odds ratio [AOR]: 2.7; 95% confidence interval [CI]: 2.1-3.4 for large child care facility vs no child care) and doctor-diagnosed LRTI (AOR: 5.6; 95% CI: 3.9-7.9). Having siblings was associated with doctor-diagnosed LRTI (AOR: 2.6; 95% CI: 2.0-3.4). In addition, children who have allergic parents and attend child care or have older siblings have a higher risk of developing doctor-diagnosed LRTI than do children who have nonallergic parents. CONCLUSIONS: Child care attendance or having siblings increases the risk of developing doctor-diagnosed LRTI in the first year of life to a greater extent in allergy-prone children than in children who are not allergy prone.