Asthma and allergic diseases in schoolchildren: third cross-sectional survey in the same primary school in Ankara, Turkey

The Effects of a Healthy Diet on Asthma and Wheezing in Children and Adolescents: A Systematic Review and Meta-Analysis

Background

Asthma is a public health problem requiring focused attention. This study aimed to systematically evaluate the association between dietary structure and asthma or wheezing in children.

Methods

The study protocol of this meta-analysis has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) with the registration code CRD42023390191. A total of 8397 articles were retrieved, searching PubMed, Medline, Embase, Web of Science, and Scopus databases as of November 21, 2022. Two independent authors were responsible for independently conducting the literature screening process. Effect-size estimates were expressed as odds ratio (OR) in cross-sectional studies and risk ratio (RR) in cohort studies with a 95% confidence interval (CI). Summary effect estimates were evaluated with random-effect models. Meanwhile, subgroup and sensitivity analyses were performed to assess the potential sources of heterogeneity and the robustness of the pooled estimation.

Results

A total of 65 studies, including 567,426 subjects had been analyzed. Overall analyses of cross-sectional studies revealed that a healthy diet was protective against asthma (adjusted OR=0.85, 95% CI: 0.80-0.89, P <0.001, I2=69.8%, Tau2=0.026) and wheezing (adjusted OR=0.85, 95% CI: 0.81-0.89, P <0.001, I2=66.8%, Tau2=0.015) in children and adolescents. Conversely, unhealthy diets can exacerbate asthma (adjusted OR=1.28, 95% CI: 1.20-1.36, P <0.001, I2=64.9%, Tau2=0.019) and wheeze (adjusted OR=1.09, 95% CI: 1.02-1.16, P =0.006, I2=75.2%, Tau2=0.023) in children and adolescents. The same trend was found in cohort studies (adjusted RR=0.72, 95% CI: 0.58-0.90, P =0.003, I2=83.5%, Tau2=0.105). A clear trend was observed between high-frequency healthy diets (OR=0.80; 95% CI: 0.71-0.89; P <0.001) is more protective against asthma than low-frequency healthy diets (OR=0.81; 95% CI: 0.70-0.94; P =0.007).

Conclusion

Our findings highlight the protective effects of a healthy diet on asthma and wheezing in children, including fruit, seafood, cereals, and the Mediterranean diet.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

Economic Burden of Pediatric Asthma in Turkey: A Cost of Illness Study from Payer Perspective

OBJECTIVES

To estimate economic burden of pediatric asthma in Turkey from payer perspective.

MATERIALS AND METHODS

This cost of illness study was based on identification of per patient annual direct medical costs for the management of pediatric asthma in Turkey from payer perspective. Average per patient direct medical cost was calculated based on cost items related to outpatient visits, laboratory and radiological tests, hospitalizations and interventions, drug treatment and equipment, and co-morbidities/complications.

RESULTS

Based on total annual per patient costs calculated for outpatient admission ($113.14), laboratory-radiological tests ($35.94), hospitalizations ($725.92), drug treatment/equipment ($212.90) and co-morbidities/complications ($144.62) cost items, total per patient annual direct medical cost related to management of pediatric asthma was calculated to be $1,232.53 from payer perspective. Hospitalizations and interventions (58.9%) was the main cost driver. Direct cost for managing controlled and uncontrolled pediatric asthma were calculated to be $530.17 [key cost driver: drugs/equipment (40.0%)] and $1,023.16 [key cost driver: hospitalization/interventions (59.0%)], respectively.

CONCLUSION

Our findings indicate that managing patients with pediatric asthma pose a considerable burden to health economics in Turkey, with hospitalizations identified as the main cost driver and two-fold cost increment in case of uncontrolled disease.

Interactions between dietary habits and home environmental exposures on respiratory symptoms in Romanian school children: an analysis of data from the SINPHONIE project

In this study, we investigated the interactions between household pollutants and dietary habits on children's respiratory health. Our cross-sectional study collected self-reported information including health symptoms (allergy-like, asthma-like, and flu-like symptoms), home characteristics, dietary habits, and demographic information from questionnaires administered to parents of 280 school children in Romania. Unconditional logistic regression and stratified analyses were used to assess the interactions between dietary factors and environmental exposures on health symptoms among children, controlling for sociodemographic characteristics and co-exposures. We found that frequency of fruit consumption had significant interaction with residing near heavy traffic on allergy-like symptoms among children (p = 0.036). However, no association was observed by frequency of fruit consumption. Although no significant interaction was observed, we found that students with infrequent fruit consumption and residing near heavy traffic roads had elevated odds of asthma-like (POR 6.37; 95% CI 1.22, 33.29) and flu-like symptoms (POR 3.75; 95% CI 1.12, 11.86) than those who frequently consumed fruits. Likewise, low vegetable consumption was associated with increased asthma-like symptoms (POR 2.93; 95% CI 1.04, 8.24). Increased odds of asthma-like symptoms were observed among school children that resided near heavy traffic roads and frequently consumed milk (POR 2.80; 95% CI 1.24, 6.31) and yoghurt (POR 2.86; 95% CI 1.05, 7.75) compared to those that infrequently consumed dairy. Our findings suggest that frequent fruit and vegetable consumption may mitigate the negative effects of exposure to heavy traffic near dwelling on respiratory symptoms in Romanian children.

Correlation between socio-economic status and atopic dermatitis in Korean adults: the Korea national health and nutrition examination survey (2007-2014)

INTRODUCTION

Atopic dermatitis (AD) is one of the most common allergic diseases. Its prevalence has been increasing in recent decades. Socio-economic status is well-known risk factor of allergic diseases.

OBJECTIVE

This study was performed to investigate the relationship between socio-economic status and AD in Korean adults.

METHODS

Data were acquired from 47 351 men and women, ≥19 years of age who participated in the Korea National Health and Nutrition Examination Surveys (KNHANES) conducted from 2007 to 2014. The presence of AD was based on self-reported physician diagnosis of AD in the Health Interview Surveys.

RESULTS

The prevalence of AD was 3.1%, which decreased with increasing age. In univariate analysis, adults with AD were prone to be female, younger, never-married, well educated, lower household members, and urban dwelling (all P < 0.01). Monthly family income and smoking status were not associated with the presence of AD. The prevalence of hypertension, diabetes mellitus and asthma was higher in AD subjects (all P < 0.01), while obesity was not associated with adult AD. After adjusting for confounders, logistic regression analysis showed female sex (adjusted odds ratio [aOR]: 1.483, 95% CI: 1.268-1.734), age (P < 0.01), marital status (Single: aOR: 1.307, 95% CI: 1.012-1.690; Never-married: aOR: 1.938, 95% CI: 1.513-2.482), urban residence (aOR: 1.281, 95% CI: 1.045-1.569) and asthma (aOR: 1.788, 95% CI: 1.416-2.258) were associated with higher prevalence of AD (all P < 0.01).

CONCLUSION

Female sex, age, marital status, urban residence, and the presence of asthma are important risk factors of the prevalence of AD in Korean adults.

Assessment of pet exposure by self-report in epidemiological studies of allergy and asthma: a systematic review

OBJECTIVE

In epidemiological studies that aim to investigate the relationship between pet exposure and allergy/asthma, pet exposure is often ascertained by means of a questionnaire, but it is unclear which questionnaire items are used. The objective of this study was to systematically review self-reported pet exposure assessment in questionnaires used in epidemiological studies which explore the associations between pets and allergy/asthma.

METHODS

A systematic literature search was conducted in PubMed and papers were selected according to pre-specified eligibility criteria. The pet exposure questions used were classified within a framework including direct pet contact, indirect pet contact (e.g. through carers or grandparents) and avoidance behaviour. Authors were contacted when the questions used were not reported in detail.

RESULTS

Ninety-six full text papers were systematically reviewed. All studies assessed direct pet contact, but less than half (45%) explicitly assessed whether pets were allowed indoors. The vast majority of studies assessed both pet exposures during the first year of life and after the first year of life. The minority (13%) assessed whether pet(s) were kept at places regularly visited by the child and pet exposure in utero (15%). Even fewer studies assessed indirect contact to pets (n = 8) and avoidance behaviour (n = 10).

CONCLUSIONS

In epidemiological studies, the ascertainment of pet exposure through questionnaires appears to vary greatly. This variation might partly explain the inconsistent and contradictory results of the effects of pet exposure on the development of allergy and asthma.

Active or passive exposure to tobacco smoking and allergic rhinitis, allergic dermatitis, and food allergy in adults and children: a systematic review and meta-analysis

BACKGROUND

Allergic rhinitis, allergic dermatitis, and food allergy are extremely common diseases, especially among children, and are frequently associated to each other and to asthma. Smoking is a potential risk factor for these conditions, but so far, results from individual studies have been conflicting. The objective of this study was to examine the evidence for an association between active smoking (AS) or passive exposure to secondhand smoke and allergic conditions.

METHODS AND FINDINGS

We retrieved studies published in any language up to June 30th, 2013 by systematically searching Medline, Embase, the five regional bibliographic databases of the World Health Organization, and ISI-Proceedings databases, by manually examining the references of the original articles and reviews retrieved, and by establishing personal contact with clinical researchers. We included cohort, case-control, and cross-sectional studies reporting odds ratio (OR) or relative risk (RR) estimates and confidence intervals of smoking and allergic conditions, first among the general population and then among children. We retrieved 97 studies on allergic rhinitis, 91 on allergic dermatitis, and eight on food allergy published in 139 different articles. When all studies were analyzed together (showing random effects model results and pooled ORs expressed as RR), allergic rhinitis was not associated with active smoking (pooled RR, 1.02 [95% CI 0.92-1.15]), but was associated with passive smoking (pooled RR 1.10 [95% CI 1.06-1.15]). Allergic dermatitis was associated with both active (pooled RR, 1.21 [95% CI 1.14-1.29]) and passive smoking (pooled RR, 1.07 [95% CI 1.03-1.12]). In children and adolescent, allergic rhinitis was associated with active (pooled RR, 1.40 (95% CI 1.24-1.59) and passive smoking (pooled RR, 1.09 [95% CI 1.04-1.14]). Allergic dermatitis was associated with active (pooled RR, 1.36 [95% CI 1.17-1.46]) and passive smoking (pooled RR, 1.06 [95% CI 1.01-1.11]). Food allergy was associated with SHS (1.43 [1.12-1.83]) when cohort studies only were examined, but not when all studies were combined. The findings are limited by the potential for confounding and bias given that most of the individual studies used a cross-sectional design. Furthermore, the studies showed a high degree of heterogeneity and the exposure and outcome measures were assessed by self-report, which may increase the potential for misclassification.

CONCLUSIONS

We observed very modest associations between smoking and some allergic diseases among adults. Among children and adolescents, both active and passive exposure to SHS were associated with a modest increased risk for allergic diseases, and passive smoking was associated with an increased risk for food allergy. Additional studies with detailed measurement of exposure and better case definition are needed to further explore the role of smoking in allergic diseases.

Minimum prick test panel for adult patients with asthma and rhinitis in Ankara, Turkey

OBJECTIVE

Determination of the number and type of allergens needed to be tested in epidemiological studies is important in order to identify most of the sensitized subjects with a cost-effective approach. This study aimed to investigate the minimum skin prick test panel for the identification of at least 95% of the sensitized subjects with symptoms of asthma and/or allergic rhinitis (AR) in Ankara, Turkey.

METHODS

Skin prick test results of 7492 patients who were referred to our outpatient clinic with clinical symptoms of asthma and/or AR between 1991 and 2005 were evaluated retrospectively. Seven allergens were tested in all and 13 allergens in 4202 patients. The allergen group needed for detection of 95% of the sensitized subjects was determined for both the 7 and 13 allergen panels. The study protocol was approved by the local ethics committee of Hacettepe University.

RESULTS

The atopy prevalences in the whole study population and in 4202 patients tested with the 13 allergen panel were calculated as 32.2% and 42.6%, respectively. Three allergens (Phleum pratense, Dermatophagoides pteronyssinus and Artemisia vulgaris) within the 7 allergen panel were adequate for the identification of at least 95% of the sensitized subjects. Olea europae was added to the previous three allergens when the 13 allergen panel was applied.

CONCLUSION

Three to four allergens are sufficient for identification at least 95% of sensitized subjects with asthma and/or AR in Ankara, Turkey.

Rising trend of allergic rhinitis prevalence among Turkish schoolchildren

OBJECTIVES

To assess the time trends and possible risk factors associated with allergic rhinitis symptoms in schoolchildren from Denizli, Turkey.

METHOD

Two identical cross-sectional surveys were performed in the 13- to 14-yr age group at intervals of six years using ISAAC questionnaire. Possible risk factors were also asked and the children completed questionnaires by self.

RESULTS

A total of 4078 children (response rate 75%) in the 2008 and 3004 children (response rate, 93.8%) in 2002 were included. The lifetime prevalence of rhinitis, 12-month prevalence of rhinitis, prevalence of associated itchy eye in the previous 12 months and doctor diagnosed allergic rhinitis prevalence were increased from 34.2% to 49.4% (POR=1.87, 95% CI=47.8-50.9 and p ≤ 0.001), from 23.5.0% to 32.9% (POR=1.59, 95% CI=31.4-34.3 and p ≤ 0.001), from 9.6% to 14.9% (POR=1.64, 95% CI=13.8-16.0 and p ≤ 0.001), and from 4.3% to 7% (POR=1.67, 95% CI=6.2-7.8 and p ≤ 0.001) respectively. Severe interference with daily activity in the previous 12 months did not change. In multivariate analysis, history of family atopy, stuffed toys, high annual family income, presence of allergy in mother, father and accompaniment of children to their parents after school hours in textile industry were found as risk factors in 2008 study.

CONCLUSION

The prevalence of allergic rhinitis increased significantly in 2008. Family history of atopy, stuffed toys, high annual family income and accompaniment of children to their parents in textile industry were found as risk factors for doctor diagnosed allergic rhinitis.

The long-term outcomes of persistent childhood allergic asthma: a cross-sectional study from western Anatolia: childhood persistent asthma in western Anatolia

BACKGROUND

Prospective cohort studies have provided useful knowledge about the natural history of asthma. However, most of the studies are conducted in western countries but the course of the disease and long-term outcomes may differ between countries due to environmental and cultural factors.

OBJECTIVE

The aim of this study is to describe the long-term outcomes of childhood asthma, with data from a follow-up study of at least 10 years, in western Anatolia, Turkey.

METHODS

Fifty-two patients diagnosed with persistent allergic asthma participated in the study. The patient's demographics, findings on admission, age at onset of disease, time of diagnosis, history of other allergic conditions, history of parental asthma and allergic disorders, presence of pharmacotherapy and immunotherapy were obtained from patients' records. The factors influencing remission at the end of 10 years follow-up were evaluated.

RESULTS

A total of 20 patients (38.5%) were on remission at the end of 10 years. The type of allergen, multi-allergen sensitivity, eosinophilia and elevated serum immunoglobulin E on admission, accompanying allergic disorders and atopy in parents, and allergen immunotherapy did not affect the remission rate (p>0.05).

CONCLUSION

Childhood persistent asthma is not a homogeneous clinical entity but high clinical remission rates are obtained in western Anatolia. There is no significant predictor of clinical remission in long term follow-up. Prospective studies should be performed in larger asthmatic populations to obtain further data about the natural course of childhood asthma.

Investigation into the use of complementary and alternative medicine and affecting factors in Turkish asthmatic patients

AIMS

The purpose of this study was to examine the frequency of complementary and alternative medicine usage in asthmatic patients living in the west of Turkey, the most frequently used complementary and alternative medicine methods and socio-demographic factors affecting this and factors related to the disease.

BACKGROUND

While the rate of complementary and alternative medicine usage in asthmatic patients and the reasons for using it vary, practices specific to different countries and regions are of interest. Differing cultural and social factors even in geographically similar regions can affect the type of complementary and alternative medicine used.

METHODS

Two hundred asthmatic patients registered in the asthma outpatient clinic of a large hospital in Turkey and who had undergone pulmonary function tests within the previous six months were included in this study, which was planned according to a descriptive design. The patients filled out a questionnaire on their demographic characteristics and complementary and alternative medicine usage.

RESULTS

The proportion of patients who reported using one or more of the complementary and alternative medicine methods was 63·0%. Of these patients, 61·9% were using plants and herbal treatments, 53·2% were doing exercises and 36·5% said that they prayed. The objectives of their use of complementary and alternative medicine were to reduce asthma-related complaints (58%) and to feel better (37·8%). The proportion of people experiencing adverse effects was 3·3% (n = 4). Factors motivating asthmatic patients to use complementary and alternative medicine were the existence of comorbid diseases and a long period since diagnosis (p < 0·05). No statistically significant difference was found between the use of complementary and alternative medicine and the severity of the disease, pulmonary function test parameters, the number of asthma attacks or hospitalisations because of asthma within the last year (p > 0·05).

RELEVANCE TO CLINICAL PRACTICE

Understanding by nurses of the causes and patterns of the use of complementary and alternative medicine in asthmatic patients helps them in directing patient care and patient safety. Nurses should conduct comprehensive diagnostics in the light of complementary and alternative medicine use, and they should be aware of the potential risks.

Association between prenatal and postnatal tobacco smoke exposure and allergies in young children

BACKGROUND

Many studies have shown a positive association between environmental tobacco smoke (ETS) exposure and allergic disorders, whereas epidemiological evidence of the effect of maternal smoking during pregnancy on allergic diseases is inconsistent. We investigated the independent and joint effects of in utero exposure to maternal smoking and postnatal ETS exposure at home on allergic disorders among Japanese children.

METHODS

Study subjects were 1951 children aged 3 years. Data on maternal smoking during pregnancy and postnatal exposure to ETS at home, allergic symptoms, and potential confounders were collected through the use of a questionnaire. Outcomes were defined according to the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC).

RESULTS

The prevalence values of symptoms of wheeze, asthma, and eczema in the previous 12 months were 22.0%, 8.8%, and 17.2%, respectively. We found that postnatal ETS exposure at home in the absence of in utero exposure to maternal smoking was associated with a higher prevalence of wheeze (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI): 1.01-1.67). In contrast, in utero exposure without subsequent postnatal ETS exposure at home or exposure to postnatal ETS at home in addition to in utero exposure to maternal smoking was not associated with the prevalence of wheeze. No measurable associations were observed between fetal, postnatal, or joint exposure and the prevalence of asthma or eczema.

CONCLUSIONS

Data from this study indicate that ETS at home may be associated with a higher prevalence of wheeze among young Japanese children.

The prevalences of allergic diseases in rural and urban areas are similar

BACKGROUND

In this study, we aimed to detect the influence of environmental and socioeconomic factors for asthma, allergic rhinitis, and eczema among children aged 6-18 years.

METHOD

Two each of schools located in urban and in rural areas were included in the study. Children in these schools were asked to respond to 32 questions in total, including demographic and socioeconomic features and the questions of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire form.

RESULTS

The average age of children included in the study was 11.5 ± 3.3 years, and the ratio of boys (55.4%) to girls (44.6%) was 1.2/1. The prevalence of asthma was found as 11.5%, allergic rhinitis as 22.1%, and eczema as 10.7%. Asthma (21.9%), allergic rhinitis (44.3%) and eczema (19.8%) were more frequent in cases which had family history of atopy (p < 0.001). Although there were differences between regions regarding income and educational levels, number of persons in the household, duration of breast feeding, and dietary habits, these variants were found inconclusive for the development of asthma. The risk of progression to asthma and atopic diseases decreased as age increased and the educational level of the father increased.

CONCLUSION

According to our results, atopic diseases can be considered frequent in Konya, history of atopy in the family is the most predictive factor and the effects of rural or urban factors are not obvious in atopic disease development.

[Regional inequalities in the prevalence of asthma diagnosis in children: an analysis of the Brazilian National Household Sample Survey, 2003]

The aim of this study was to estimate the prevalence of asthma diagnosis in Brazilian children and to analyze socio-demographic inequalities between the South and Northeast regions of the country. Data for children under 10 years of age were analyzed from the 2003 National Household Sample Survey, or PNAD (n = 69,796). Socioeconomic characteristics, the child's gender and age, and the parent or guardian's skin color were the independent variables investigated through unconditional multiple logistic regression. Prevalence of asthma diagnosis was 8.5% in Brazil as a whole (95%CI: 7.7-8.5) and 12.6% (95%CI: 11.6-13.5) and 4.4% (95%CI: 4.0-4.8) in the South and Northeast, respectively. After adjustment, children from 3 to 7 years of age and those from the poorest families were more likely to have an asthma diagnosis in both regions. Black skin color, crowding, and substandard housing were associated with asthma in the South. In the Northeast, children of parents with low schooling were less likely to present asthma. The inequalities were more evident in the South, suggesting variation in asthma determinants across the country.

Asthma and allergic diseases in school children from 1992 to 2007 with incidence data

BACKGROUND

Information about change in the prevalence of asthma and allergic diseases and factors related with these diseases would be beneficial in decreasing the burden of these diseases.

OBJECTIVE

To assess (i) change in prevalence of asthma and allergic diseases; (ii) factors associated with asthma and wheeze; and (iii) incidence of asthma and wheeze.

METHODS

A questionnaire was administered to children aged 7-12 years in first five grades in the same primary school in 1992 (n: 1036), 1997 (n: 738), 2002 (n: 621), and 2007 (n: 422) and filled by the parents. A second survey in 2007 (n: 474, in eight grades) was conducted in the same schoolchildren, 6 months apart, to assess the incidence of asthma and wheeze and the associated factors.

RESULTS

Comparison of 1992, 1997, 2002, and 2007 surveys revealed that prevalence of asthma (8.3%, 9.8%, 6.4%, 3.3%, respectively), wheeze (11.9%, 13.3%, 6.4%, 3.1%, respectively), hay fever (15.4%, 14.1%, 7.2%, 3.1%, respectively), and eczema (4.0%, 4.3%, 1.8%, 1.2%, respectively) were significantly lower in 2002 and 2007 compared with that in 1992. Percentage of passive smoking decreased after 1992 (74.0%, 64.0%, 64.1%, and 65.5%, respectively). Incidence of asthma and wheeze in 2007 surveys were 0.9/100 and 1.1/100, respectively. After the adjustment for age and gender, infection in the past, family atopy, and presence of atopic disease (eczema or hay fever) were associated with asthma and wheeze. Maternal smoking and lack of breast feeding were associated with asthma. Male gender, pet ownership in the past, lack of health insurance coverage, snoring, and wood or coal used as fuel were associated with wheeze.

CONCLUSIONS

Decreased prevalence of asthma and allergic diseases in the last 10 years could be related to decreased rate of passive smoking. Lower socioeconomic status and lack of breast feeding could increase the risk of asthma in children.

An assessment of indoor air concentrations and health risks of volatile organic compounds in three primary schools

Concentrations of volatile organic compounds (VOCs), including formaldehyde, in classrooms, kindergartens, and outdoor playgrounds of three primary schools were measured in spring, winter, and fall terms in İzmir, Turkey. A health-risk assessment was conducted for odor detection, sensory irritation, chronic toxic effects, and cancer. Active sampling was applied for VOCs and formaldehyde on Tenax TA and DNPH tubes, respectively. VOCs were analyzed in a thermal desorption-GC-MS system. Formaldehyde analysis was performed using an HPLC instrument. Benzene, toluene, and formaldehyde were the most abundant compounds with 95th percentile indoor air concentrations of 29, 87, and 106 μg/m(3), respectively. Naphthalene and xylenes followed them with an order of magnitude lower concentrations. Two isomers of dichlorobenzene (1,3 and 1,4) were the other notable compounds. The concentrations were utilized to classify the indoor air pollutants with respect to potential health effects. In addition, carcinogenic and chronic toxic risks were estimated using Monte-Carlo simulation. Formaldehyde appears to be the most concerning pollutant with high chronic toxic and carcinogenic risk levels according to the health assessment followed by naphthalene, benzene, and toluene due to their chronic effects.

Prevalence of asthma and allergic diseases in primary school children in Edirne, Turkey, two surveys 10 years apart

To assess change in prevalence and risk factors of asthma and allergic diseases among primary school children in rural and urban parts of Edirne, Turkey, a series of cross-sectional studies were conducted in 1994 and 2004. A questionnaire was administered to the parents of primary school children aged 7-12, in urban and rural parts of Edirne, Turkey (5412 in 1994 and 5735 in 2004). Response rates in 1994 and 2004 were 84% and 82.5%, respectively. There were significant differences between the age distribution, urban habitation (1994: 70.1%, 2004: 75.8%, p < 0.001), passive smoking (1994: 74.7%, 2004: 60.0%, p < 0.001), and family atopy (1994: 12.7%, 2004: 18.2%, p < 0.001) between the two surveys. Current prevalence of asthma and wheeze increased in the 2004 when compared to 1994 in both rural and urban regions (current asthma for rural and urban regions, 5.2% and 5.8% in 1994; 8.6% and 12.1% in 2004, respectively). Female-to-male ratio of current asthma increased from 0.7 in 1994 to 0.9 in 2004. Comparison of the risk factors in the two surveys suggested urban habitation and factors other than family atopy, passive smoking and no breast feeding as possible contributors for the increasing asthma and wheeze. Prevalence of asthma and allergic diseases increased among school children in Edirne, Turkey from 1994 to 2004. Life style changes and urbanization could be related to this increasing trend.

The role of cats and dogs in asthma and allergy--a systematic review

Studies have reported contradictory effects of cat and dog exposure on allergy, resulting in inconsistent recommendations on animal avoidance. We conducted a systematic review of observational studies published in English from 2000 to January 2009. It shows in this review that the reported exposure-response relationships are contradictory. A total of 17 and 13 birth cohort studies on cat and dog exposure, respectively, are included in the review. Most of the birth cohort studies found that cat or dog exposure in early life had no effect on the development of asthma or wheezing symptoms and dog exposure during infancy was found to protect children from developing sensitization against aeroallergens. A total of 7 and 6 prospective studies in school-age children or adults on cat and dog exposure, respectively, are included in this review and most of these studies suggested an inverse association between cat exposure and asthma and wheezing symptoms. As for cross-sectional studies, 26 and 21 studies on cat and dog exposure, respectively, are included in this review, which cover a broad range of age groups and geographical areas, and reported inconsistent results. The evidence summarised in this systematic review needs to be interpreted with caution, the inconsistent study results may be due to study design, exposure assessment, and avoidance measure. The exposure-response relationships may also alter in geographical areas where the community prevalence of cats and dogs are significantly different. However, as the evidence of the effects of pet keeping on subsequent development of asthma or allergic diseases presented in this review are not overwhelmingly strong, the decision of whether to keep a cat or a dog in the family should be based on arguments other than the concern of developing asthma and allergy.

Increase in chronic or recurrent rhinitis, rhinoconjunctivitis and eczema among schoolchildren in Greece: three surveys during 1991-2003

The prevalence of allergic rhinitis, hay fever and eczema has risen worldwide during the last four decades but may have reached a plateau in some westernized societies. We examined time trends in the prevalence of childhood chronic or recurrent rhinitis, rhinoconjunctivitis and eczema in urban Greece. Using identical methodology, three population-based cross-sectional parental questionnaire surveys on current (last two years) and lifetime allergic symptoms of the nose, eyes and skin were performed among 8-10-yr-old children in 1991, 1998 and 2003 in Patras, Greece. Exactly 2417, 3006 and 2725 questionnaires were completed in 1991, 1998 and 2003, respectively. Prevalence rates of current (lifetime) symptoms of chronic or recurrent rhinitis were 5.1% (6.0%) for 1991, 6.5% (8.0%) for 1998 and 8.0% (9.8%) for 2003. Respective values for rhinoconjunctivitis were 1.8% (2.1%), 2.7% (3.4%) and 3.6% (4.6%) and for eczema 2.5% (4.5%), 3.4% (6.3%) and 5.0% (9.5%) (p for trend <0.001). Among current asthmatics there was an increase in lifetime rhinitis (p = 0.038), current (p = 0.025) and lifetime rhinoconjunctivitis (p = 0.007) and current (p = 0.001) and lifetime eczema (p < 0.001); male predominance increased throughout the study. The proportion of atopic asthma (current asthma with chronic or recurrent rhinitis and/or rhinoconjunctivitis and/or eczema) increased during the same period (p < 0.001). In conclusion, there is a continuous increase in the prevalence of allergic manifestations among preadolescent children in Patras, Greece during the period 1991-2003. In our population, boys have contributed to this increase more than girls and the increase of atopy is, at least partially, responsible for the increase of asthma.

Nutrition and children's respiratory health in Guangzhou, China

OBJECTIVE

To investigate the role of nutrition in children's respiratory health in subjects participating in a study on air pollution and respiratory health.

STUDY DESIGN

Cross-sectional survey.

METHODS

The relationships between consumption of fresh fruit, vegetables and milk and pulmonary function (forced expiratory volume in 1 s, FEV(1)) and respiratory symptoms (phlegm with cold, phlegm without cold, cough with cold, and cough without cold) were examined in 2228 children (age 10.07+/-0.86 years) in Guangzhou, China.

RESULTS

A positive association was found between consumption of leafy vegetables and lung function in children. Subjects with the highest consumption of leafy vegetables had significant higher FEV(1) values than subjects who ate leafy vegetables less than once per week (1.68 l vs 1.56 l; P=0.047). Children with high consumption of fresh fruit and milk had higher lung function values than children with low consumption, although the differences were not statistically significant. Milk consumption was a protective factor for phlegm with cold, cough with cold, and cough without cold [odds ratio (OR) 0.62, 95% confidence interval (CI) 0.39-0.97; OR 0.53, 95% CI 0.36-0.79; OR 0.43, 95% CI 0.21-0.92, respectively, in the highest intake group]. Consumption of vegetables was a protective factor for cough with cold (P for trend=0.003) and cough without cold (P for trend=0.028). Consumption of fresh fruit was marginally associated with reduced prevalence of respiratory symptoms.

CONCLUSIONS

This study suggests that dietary nutrients are important protective factors for children's respiratory health. Following-up these children may provide more evidence to confirm these associations.

Prevalence and risk factors of asthma and allergic diseases among schoolchildren in Bolu, Turkey

AIM

In this study we aimed to detect the prevalence and risk factors of asthma and allergic diseases in children aged between 7 and 14 years old at rural and urban areas of Bolu, Turkey.

METHODS

Questionnaire of International Study of Asthma and Allergies in Childhood (ISAAC) phase one and questionnaire including questions about family, demographic, socio-economic characteristics of children were applied to 931 schoolchildren who were selected by randomized sampling.

RESULTS

In children, the prevalence of diseases and symptoms were as follows: wheeze ever: 15.5%, asthma: 5.6%, nasal symptoms ever: 41.4%, allergic rhinitis: 23.2%, itchy rash ever: 5.9% and eczema: 5.0%. In multivariate regression analysis, presence of allergic disease in the family was risk factor for wheezing (OR=1.74, 95% CI=1.19-2.76), asthma (OR=2.19, CI=1.06-4.52), allergic rhinitis (OR=2.68, CI=1.80-3.98) and eczema (OR=2.33, CI=1.17-4.65); living in shanties was risk factor for allergic rhinitis (OR=5.26, CI=2.1-13.16); a monthly income below $300 was risk factor for asthma (OR=2.54, CI=1.06-6.08).

CONCLUSION

It was detected that the prevalence of allergic rhinitis and its symptoms was more common in schoolchildren living in Bolu. Presence of allergic disease in fathers or mothers and low socio-economic level increase the risk of asthma and other allergic diseases in children.

Common characteristics of upper and lower airways in rhinitis and asthma: ARIA update, in collaboration with GA(2)LEN

This update aimed to review the new evidence available to support or refute prior Allergic Rhinitis and its Impact on Asthma (ARIA) statements. A Medline search of publications between 2000 and 2005 was conducted, with articles selected by experts. New evidence supports previous ARIA statements, such as: (i) allergic rhinitis (AR) is a risk factor for asthma; (ii) patients with persistent rhinitis should be evaluated for asthma; (iii) most patients with asthma have rhinitis; (iv) a combined strategy should be used to treat the airways and (v) in low- to middle-income countries, a different strategy may be needed. The increased risk of asthma has also been found among sufferers from non-AR. Recent reports show AR is a global problem. Many studies demonstrated parallel increasing prevalence of asthma and rhinitis, but in regions of highest prevalence, it may be reaching a plateau. Factors associated with a reduced risk of asthma and AR have been identified, confirming previous findings of protection related to exposure to infections. Treatment of rhinitis with intranasal glucocorticosteroids, antihistamines, leukotriene antagonists or immunotherapy may reduce morbidity because of asthma. To take advantage of the paradigm of unified airways, there is a need to rationalize diagnosis and treatment to optimize management.

The association of diet with respiratory symptoms and asthma in schoolchildren in Taipei, Taiwan

This study aimed to evaluate the association of diet with respiratory symptoms and asthma in schoolchildren in Taipei, Taiwan. An in-class interview survey elicited experiences of asthma and respiratory symptoms and consumption frequencies of the major food categories in 2290 fifth graders. Respiratory symptoms surveyed included persistent cough, chest tightness, wheezing with cold, wheezing without cold, dyspnea-associated wheezing, and exercise-induced cough or wheezing. Results showed that the consumption of sweetened beverages had the strongest association with respiratory symptoms and was positively associated with six of the seven respiratory symptoms (all p < 0.05). The adjusted odds ratios (aOR) ranged from 1.05 (95% confidence interval (CI = 1.01-1.09) for exercise-induced cough to 1.09 (95% CI = 1.03-1.16) for wheezing without cold. Egg consumption was associated with 5 of the 7 respiratory symptoms. Consumptions of seafood, soy products, and fruits were each negatively associated with one of the seven respiratory symptoms (all p < 0.05). Consumption of seafood was negatively associated with physician-diagnosed asthma and consumptions of sweetened beverages and eggs were positively associated with suspected asthma (p < 0.05). In conclusion, the study suggests that diet is associated with the respiratory symptoms in schoolchildren in Taipei. Consumptions of sweetened beverages and eggs are associated with increased risk of respiratory symptoms and asthma whereas consumptions of soy products and fruits are associated with reduced risk of respiratory symptoms.

Prevalence of Asthma and Wheeze in Relation to Passive Smoking in Japanese Children

PURPOSE

Evidence remains inconclusive as to whether environmental tobacco smoke is a risk factor for allergic disorders in childhood. The present large-scale cross-sectional study examined the relationship between passive smoking at home and the prevalence of allergic disorders in Japanese schoolchildren.

METHODS

Study subjects were 23,044 children aged 6 to 15 years in Okinawa. Outcomes were based on diagnostic criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for sex, age, region of residence, number of siblings, paternal and maternal history of asthma, atopic eczema, or allergic rhinitis, as well as paternal and maternal educational level.

RESULTS

The prevalence of wheeze, asthma, atopic eczema, and allergic rhinoconjunctivitis in the previous 12 months was 10.7%, 7.6%, 6.8%, and 7.7%, respectively. Current heavy passive smoking and 7.0 or more pack-years of smoking in the household were independently related to an increased prevalence of wheeze and asthma, especially in children 6 to 10 years of age and children with a positive parental allergic history. There was no dose-response relationship between pack-years of smoking in the household and atopic eczema or allergic rhinoconjunctivitis.

CONCLUSIONS

Our findings suggested that environmental tobacco smoke might be associated with an increased prevalence of wheeze and asthma in Japanese children.

Prevalence and risk factors of allergies in Turkey: Results of a multicentric cross-sectional study in children

The Prevalence And Risk Factors of Allergies in Turkey (PARFAIT) study was planned to evaluate prevalence and risk factors of asthma and allergic diseases and also to find out which geographical variables and/or climatic conditions play a role determining the prevalence of allergic diseases in Turkish school children. Study was planned as cross-sectional questionnaire-based. About 25,843 questionnaires from 14 centers were appropriate for analysis. Parental history of allergy, having an atopic sibling and other atopic disease in index case was significant risk factors for all allergic diseases. Breast feeding decreased the risk of current asthma (OR: 0.92, CI: 0.86-0.99) and wheezing (OR: 0.93, CI: 0.87-0.99) but not allergic rhinitis and eczema. Respiratory infection in the past was an important risk factor for the occurrence of allergic diseases especially for asthma which was increased 4.53-fold. Children exposed to household smoke were significantly at higher risk of asthma, wheezing, and allergic rhinitis (OR: 1.20, CI: 1.08-1.33; OR: 1.21, CI: 1.09-1.34; and OR: 1.32, CI: 1.21-1.43, respectively). All allergic diseases were increased in those children living in areas which have altitude of below 1000 m and mean yearly atmospheric pressure above 1000 mb. The study has suggested that household and country-specific environmental factors are associated with asthma, wheezing, allergic rhinitis, and eczema risk during childhood in Turkey.

Are risk factors of childhood asthma predicting disease persistence in early adulthood different in the developing world?

BACKGROUND

Predictive factors of childhood asthma for favorable prognosis may differ between populations where a variety of genetic and environmental factors are present.

OBJECTIVES

To document the factors predicting disease persistence in early adulthood in Turkey.

METHODS

An outpatient cohort (n = 115) with a mean follow-up duration of 11.4 +/- 0.2 years was evaluated. Complete remission was defined as no asthma symptoms, no use of controller medication, no airflow limitation and no airway hyper-responsiveness, and clinical remission as no symptoms and no use of controller medication, within the past year.

RESULTS

The mean ages during referral and at the final visit were 5.8 +/- 0.2 and 17.1 +/- 0.2 years, respectively. Thirty-one (27%) were in complete remission, and a further 30 (26%) in clinical remission. In multivariate logistic models, diminished airflow [forced expiratory volume in 1 s (FEV1) < 80% vs > or = 80%] at the initial lung function test predicted current diminished airflow (8.422; 2.202-32.206) (odds ratio; 95% confidence interval), and presence of obstructive pattern (FEV1/forced vital capacity (FVC) < 80% vs > or = 80%) predicted current obstructive pattern (29.333; 3.022-284.724). Furthermore, female gender appeared to predict persistence of asthma symptoms (3.330; 1.250-8.333) and absence of clinical remission (2.398; 1.038-5.254); eosinophilia predicted persistence of symptoms (4.271; 1.080-16.889) and presence of airway hyper-responsiveness (3.723; 1.129-12.278).

CONCLUSIONS

Diminished airflow, female gender and eosinophilia appear to predict an adverse outcome of childhood asthma, supporting the concept that variability may exist between populations.

Burden of rhinitis in children with asthma

Although the clinical association of allergic rhinitis and asthma has been recognized for centuries, in recent years the association appears to be stronger than was reported previously. However, data for children are less clear, and some studies indicate that results observed in developing countries may differ from those observed in Western populations. We therefore intended to document the association of rhinitis with pediatric asthma in terms of caregivers' perception, physician practice, and file records. Asthmatic children aged 3-16 years with at least 1-year follow-up in an allergy-asthma outpatient clinic were invited to participate in the study during a 10-month interval. In addition to a face-to-face questionnaire-based interview, file records were evaluated retrospectively to obtain information relating to asthma and rhinitis. Of 396 patients included in the study, 369 with consistent replies were included in the analyses. The mean age of the study group was 10.6 +/- 0.2 (mean +/- SEM) years, and a greater proportion of the respondents were male (63.7%), atopic (78.3%), and mildly asthmatic (50.7%). House dust mite and grass pollens were the most commonly sensitized allergens (50.7% and 46.9%, respectively). Although only 5.4% of our study population regarded themselves as rhinitic and 23.8% had been diagnosed with allergic rhinitis according to the file records, almost 57.7% of patients had required medications for rhinitis within the last year, and 68.8% had findings consistent with allergic rhinitis. Furthermore, 41.2% and 58.8% reported that their rhinitis symptoms caused a significant burden in their daily life and exacerbated their asthma, respectively, and almost 50% felt that their rhinitis had not been given significant consideration by their physician. In conclusion, although we report a large discrepancy between caregivers' perception of rhinitis, documentation in file records, and treatments for rhinitis, the allergic rhinitis prevalence determined in the survey and the medication use for rhinitis appeared to be in agreement. We recommend a greater effort be made to identify, label, and educate children with rhinitis and their families in asthma outpatient clinics.