Time trend of asthma prevalence among school children in Taiwan. [corrected]

Long-term PM2.5 exposure is associated with asthma prevalence and exhaled nitric oxide levels in children

BACKGROUND

Exhaled nitric oxide concentration (FENO) is a marker of airway inflammation. This study aimed to evaluate the association of air pollution exposure with FENO levels and asthma prevalence with respiratory symptoms in school children.

METHODS

We analyzed 4736 school children who reside in six townships near industrial areas in central Taiwan. We evaluated asthmatic symptoms, FENO, and conducted the environmental questionnaire. The personal exposure of PM2.5, NO, and SO2 was estimated using land-use regression models data on children's school and home addresses.

RESULTS

Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma (OR = 1.595), exercise-induced wheezing (OR = 1.726), itchy eyes (OR = 1.417), and current nasal problems (OR = 1.334) (P < 0.05). FENO levels in the absence of infection were positively correlated with age, previous wheezing, allergic rhinitis, atopic eczema, near the road, and for children with high exposure to PM2.5 (P < 0.05). An increase of 1 μg/m3 PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels for children after adjusting for potential confounding variables, including exposures to NO and SO2.

CONCLUSIONS

Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children.

IMPACT

Annual exposure to PM2.5 was associated with increased odds of physician-diagnosed asthma and nasal problems and itchy eyes. Long-term exposures to PM2.5 were significantly associated with FENO levels after adjusting for potential confounding variables. This is first study to assess the association between FENO levels and long-term air pollution exposures in children near coal-based power plants. An increase of 1 μg/m3 annual PM2.5 exposure was significantly associated with a 1.0% increase in FENO levels. Long-term exposures to PM2.5 posed a significant risk of asthma prevalence and airway inflammation in a community-based population of children.

SABA prescriptions and asthma management practices in patients treated by specialists in Taiwan: Results from the SABINA III study

PURPOSE

Limited data exist on asthma medication patterns in Taiwan. The objectives of the SABINA III cross-sectional study in Taiwan were thus, to describe patient demographics and clinical features and estimate short-acting β₂-agonist (SABA) and inhaled corticosteroids (ICS) prescriptions per patient.

METHODS

Patients (≥18 years) with asthma were classified by investigator-defined asthma severity per the 2017 Global Initiative for Asthma (GINA) recommendations. Data on asthma symptom control (per GINA 2017 recommendations), severe exacerbation history, and prescribed treatments in the 12 months before study visit were collected using electronic case-report forms. Analyses were descriptive.

RESULTS

Overall, all 294 analyzed patients (mean [SD] age, 57.9 [15.6] years; female, 69%) were enrolled by specialists and had fully reimbursed healthcare. Most patients were classified with moderate-to-severe asthma (93.2%; GINA steps 3-5), were obese (53.4%) and nonsmokers (79.6%), reported high school or university and/or postgraduate education (61.9%), and had ≤2 comorbidities (89.1%). Mean (SD) asthma duration was 8.3 (10.0) years, with 37.8% of patients experiencing ≥1 severe exacerbation 12 months before the study visit. Overall, 62.2%, 26.2%, and 11.6% of patients had well-controlled, partly controlled, and uncontrolled asthma, respectively. Crucially, 19.3% of patients were prescribed ≥3 SABA canisters in the preceding 12 months (overprescription). ICS, ICS + long-acting β_2-agonist fixed-dose combination, and oral corticosteroid bursts were prescribed to 6.5%, 97.3%, and 31.6% of patients, respectively.

CONCLUSION

Despite treatment by specialists and fully reimbursed healthcare, findings indicate room for improvement in asthma control and SABA prescription practices in Taiwan, emphasizing the need to adhere to latest evidence-based guidelines.

Small Airway Dysfunction Measured by Impulse Oscillometry and Fractional Exhaled Nitric Oxide Is Associated With Asthma Control in Children

BACKGROUND

Impulse oscillometry (IOS) and fractional exhaled nitric oxide (FeNO) are sensitive and non-invasive methods to measure airway resistance and inflammation, although there are limited population-based studies using IOS and FeNO to predict asthma control.

OBJECTIVE

This study aimed to investigate the utility of IOS and FeNO for assessing childhood asthma control in terms of small airway dysfunction and airway inflammation.

METHODS

This prospective observational cohort study enrolled 5,018 school children (aged 6-12 years), including 560 asthmatic children and 140 normal participants. FeNO, spirometry, IOS, bronchial dilation test, total IgE, and childhood asthma control test (C-ACT) were measured. FeNO, IOS, spirometry, and C-ACT results were correlated with childhood asthma with and without control.

RESULTS

Uncontrolled asthmatic children had abnormal FeNO, IOS, and spirometric values compared with control subjects (P < 0.05). IOS parameters with R5, R5-R20, X5, Ax, △R5, and FeNO can predict lower C-ACT scales by the areas under receiver operating characteristic curves (AUCs) (0.616, 0.625, 0.609, 0.622, 0.625, and 0.714). A combination of FeNO (>20 ppb) with IOS measure significantly increased the specificity for predicting uncontrolled asthma patients compared with FeNO alone (P < 0.01). A multiple regression model showed that small airway parameter (R5-R20) was the strongest risk factor [OR (95% CI): 87.26 (7.67-993.31)] for uncontrolled asthma patients. Poor control with lower C-ACT scales correlated with high FeNO (r = -0.394), R5 (r = -0.106), and R5-R20 (r = -0.129) in asthmatic children (P < 0.05).

CONCLUSION

A combined use of FeNO and IOS measurements strongly predicts childhood asthma with or without control.

Pediatric thalassemic patients have higher incidence of asthma: A nationwide population-based retrospective cohort study

Introduction

Patients with hemoglobinopathies have been reported to have higher rates of pulmonary complications. Few studies have investigated the association between thalassemia and asthma in children.

Methods

We used the data of one million individuals randomly selected from the Registry for Beneficiaries of the National Health Insurance Research Database. One thalassemic child was matched with four control children without thalassemia according to sex, birth year, birth season, prematurity, and previous enteroviral infection.

Results

A total of 800 hundred thalassemic children and 3200 controls were included. Children with thalassemia had higher rates of developing asthma (41.81 vs 25.70 per 1000 person-years, P < 0.001) than the non-thalassemia controls with an adjusted hazard ratio of 1.37 (95% confidence interval [CI] = 1.19–1.58). Boys in the thalassemia cohort had a significantly higher adjusted incidence hazard ratio (IRR) of asthma than those in the non-thalassemia cohort (adjusted IRR = 1.45, 95% CI = 1.02–1.73). The risk of atopic and nonatopic asthma was higher in the thalassemia cohort than in the non-thalassemia cohort (IRR = 1.3, 1.61, respectively).

Conclusions

Children with thalassemia were more likely to develop asthma. More attention should be paid to the early diagnosis of asthma and prevention of asthma attacks.

Effect of environmental exposures on allergen sensitization and the development of childhood allergic diseases: A large-scale population-based study

Background

Changing environmental factors are likely responsible for the rising prevalence of allergic diseases in children. However, whether environmental exposures induce allergen sensitizations, and which allergen sensitization is related to the development of allergic diseases, is not clear. The study is aimed to investigate the association between environmental exposure, allergen sensitization, and the development of allergic diseases for further preventive intervention.

Methods

We conducted the Taiwan Childhood Environment and Allergic diseases Study (TCEAS) in kindergarten children in Taiwan. Skin prick tests for 6 allergens were performed. Information on the development of allergic diseases and environmental exposure was collected using standardized questionnaires. Multiple logistic regressions were used to estimate the association between environmental factors, allergen sensitization, and the development of allergic diseases.

Results

A total of 3192 children were recruited. 485 (15.2%) children had atopic dermatitis (AD), 1126 (35.3%) had allergic rhinitis (AR), and 552 (17.3%) had asthma. Children with environmental tobacco smoke exposure and fungi on the house wall had a higher risk of asthma, with ORs (95% CIs) of 1.25 (1.03–1.52) and 1.22 (1.01–1.47), respectively. The mite sensitization rate was found to be the highest. Mite sensitization was associated with significant increases in the risks of AD, AR, and asthma, with ORs (95% CIs) of 2.15 (1.53–3.03), 1.94 (1.46–2.58), and 2.31 (1.63–3.29), respectively. Cockroach sensitization also increased the risk of asthma, with an OR (95% CI) of 2.38 (1.01–5.61). Mite sensitization was associated with carpet in the home and fungi on the house wall, and milk sensitization was associated with breastfeeding duration.

Conclusion

Environmental exposures play a role in the development of allergic diseases. Allergen sensitizations were associated with certain environmental exposures. Early environmental interventions are urgently needed to prevent the development of childhood allergic diseases.

Tai Chi Chuan Exercise Improves Lung Function and Asthma Control through Immune Regulation in Childhood Asthma

Background

Tai Chi Chuan (TCC) is an exercise of low to moderate intensity with key features of mindfulness, structural alignment, and flexibility to relax the body and mind in adults. Our previous study showed that TCC could improve the quality of life (QoL), pulmonary function, and fractional exhaled nitric oxide in asthmatic children. We further investigated whether the benefits induced by TCC were associated with immune regulation.

Method

Six- to twelve-year-old children diagnosed with mild to severe persistent asthma for at least one year according to the Global Initiative for Asthma guidelines were enrolled from a tertiary pediatric allergy center in Taiwan. Asthmatic children were divided into two groups based on their choice: (1) the TCC group had a 60-minute TCC exercise session once weekly led by an instructor and (2) the control group kept their original activity levels. All other exercises were encouraged as usual. Pulmonary function tests, laboratory tests, standardized pediatric asthma QoL questionnaire (PAQLQ(S)), and childhood asthma control test (C-ACT) were performed before and after the TCC program (12 weeks). Data on medications and exacerbations were collected from medical records.

Results

There were no differences between the TCC (n = 25) and control (n = 15) groups at baseline, except that the C-ACT showed significantly lower results in the TCC group (p=0.045). After 12 weeks, the number of leukocytes (p=0.041) and eosinophils (p=0.022) decreased, while regulatory T cells increased significantly (p=0.008) only in the TCC group. Lung functions (FEV₁ and PEFR) were significantly improved in both the TCC (p < 0.001) and control (p=0.045 and 0.019, respectively) groups, while the PAQLQ(S) and C-ACT (p < 0.001) showed improvement only in the TCC group. Moreover, compared to the control group, the exacerbations within 12 weeks after the study were significantly decreased in the TCC group (p=0.031). After multiple regression by a conditional forward method, the factors that were significantly associated with exacerbation within 12 weeks after study is the practice of TCC and exacerbation within 24 weeks before study (p=0.013 and 0.015, respectively) after adjusting for age, sex, asthma severity, PEF, FEV₁, C-ACT, PAQLQ(S), and medication score at baseline.

Conclusion

TCC exercise may improve pulmonary functions, asthma control, and QoL and prevent exacerbations in asthmatic children through immune regulation. Further research on detailed mechanisms is mandated.

Prescription Patterns and Burden of Pediatric Asthma in Korea

Purpose

This study aimed to estimate the prevalence, prescription pattern and burden of pediatric asthma in Korea by analyzing the National Health Insurance (NHI) claims data.

Methods

We retrospectively analyzed the insurance claim records from the Korean NHI claims database from January 2010 to December 2014. Asthmatic patients were defined as children younger than 18 years, with appropriate 10th Revision of the International Classification of Diseases codes (J45 or J46) and a prescription for 1 or more asthma maintenance medications at the same date. Hospitalization and emergency department visits for asthma were defined as use of short-acting beta₂-agonists during hospital visits among asthmatic patients.

Results

There were 1,172,807 asthmatic children in 2010, which increased steadily to 1,590,228 in 2014 in Korea. The prevalence showed an increasing trend annually for all ages. The mean prevalence by age in those older than 2 years decreased during the study period (from 39.4% in the 2–3 year age group to 2.6% in the 15–18 year age group). In an outpatient prescription, leukotriene receptor antagonists were the most commonly prescribed medication for all ages. Patients older than 6 years for whom inhaled corticosteroids were prescribed comprised less than 15% of asthmatic patients. The total direct medical cost for asthma between 2010 and 2014 ranged from $376 to $483 million. Asthma-related medical cost per person reached its peak in $366 in 2011 and decreased to $275 in 2014.

Conclusions

The prevalence of pediatric asthma increased annually and decreased with age. Individual cost of asthma showed a decreasing trend in Korean children.

Comparative efficacy and tolerability of beclomethasone/formoterol and fluticasone/salmeterol fixed combination in Taiwanese asthmatic patients

BACKGROUND

The study was designed to compare the efficacy and tolerability of a fixed combination of extra-fine beclomethasone and formoterol, with the fixed combination fluticasone and salmeterol in Taiwanese asthmatic patients.

METHODS

This was a phase III, multicentre, randomized, two-arm parallel groups, controlled study. Patients with moderate to severe asthma were randomized to a 12-week treatment with either beclomethasone 100 mcg plus formoterol 6 mcg (BDP/F) or fluticasone 125 mcg plus salmeterol 25 mcg (FP/S), both delivered 2 inhalations twice daily. The efficacy and tolerability of these two combinations were compared.

RESULTS

Among the 253 randomized subjects, 244 patients were evaluable (119 in the BDP/F group and 125 in the FP/S group). A significant improvement from baseline to the end of treatment period was observed in both BDP/F and FP/S groups in forced expiratory volume in the first second (FEV₁), forced vital capacity (FVC), morning and evening peak expiratory flow (PEF), Asthma Control Test (ACT) score and the use of rescue medication. FVC increase from pre-dose was significant after 5 min post inhalation in the BDP/F group only, while statistically significant within group improvement was not achieved until 30 min post inhalation in the FP/S group.

CONCLUSION

The BDP/F combination is comparable in efficacy and tolerability to FP/S combination in Taiwanese asthmatic patients, with the advantage of rapid onset of improvement of FVC, consistent with the faster improvement of pulmonary hyperinflation with BDP/F.

The effect of size-segregated ambient particulate matter on Th1/Th2-like immune responses in mice

Background

Particulate matter (PM) has been associated with increased pulmonary and cardiovascular mortality and morbidity. Additionally, PM is known to exacerbate asthma. However, whether ambient PM exposure contributes to the onset of asthma, especially in non-atopic children and adults, is less conclusive. The current study aimed to evaluate the effects of size-fractioned PM on lung immune responses in healthy BALB/c mice.

Methods and principal findings

We collected PM₁₀, PM_2.5, PM₁ and PM_0.1 samples from October 2012 to August 2013 in the Taipei Basin. These PM samples were representative of urban traffic pollution. The samples were extracted and sonicated in phosphate-buffered saline (PBS). Female BALB/c mice were exposed to the samples via intratracheal instillation at three different doses: 1.75 mg/kg (35 μg/per mouse), 5 mg/kg (100 μg/per mouse), and 12.5 mg/kg (250 μg/per mouse). The mice were exposed on days 0 and 7, and PBS alone was used as a control. Following the exposures, the expression profiles of inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were assessed. Exposure to PM₁₀ resulted in inflammatory responses, including the recruitment of neutrophils and the induction of T helper 1 (Th1) cell-related cytokine release, such as TNF-α and IFN-γ. Furthermore, an allergic immune response, including the recruitment of eosinophils and the up-regulation of T helper 2 (Th2) cell-related cytokine release, such as IL-5 and IL-13, was also observed in the BALF of mice exposed to PM₁₀.

Conclusions

Our study showed that exposure to PM alone caused mixed Th1/Th2 inflammatory responses in healthy mice. These findings support the hypothesis that PM may contribute to the onset of asthma.

Prevalence of asthma among Middle Eastern children: A systematic review

Background: The prevalence of asthma and allergy has increased during the last decades, especially in children. However, little is known about it in the Middle East region. This systematic review is aimed to estimate the prevalence of asthma among the Middle Eastern children.

Methods: Local and international scientific databases including SID, Iranmedex, Medline and Science Direct were systematically searched for relevant keywords including; asthma, prevalence, children, International Study of Asthma and Allergies in Childhood (ISACC) and the names of Middle Eastern countries for the period of 1996-2011. Papers in Persian and English which met the defined criteria were included into the study. Bibliographies of the extracted articles were also searched. After extraction of data, heterogeneity between studies and publication bias were measured using Egger's-test. Effect size was pooled by the random-effect model. Since significant heterogeneity was found between studies, univariate meta-regression analyses were done to assess the association of variables with the overall results.

Results: Fifty studies in the Middle East examined the prevalence of asthma and allergy in children under the age of 18 years according to the ISAAC criteria and were included. A total number of 289,717 children were examined in the included studies and the prevalence varied from 0.7 % in Isfahan to 22.3 % in Bagdad. The total prevalence of diagnosed asthma was calculated 7.53 % (95% Cl: 6.38-8.75). Prevalence of asthma in the 13-14 years age group was 7.57% (95% Cl: 5.78-9.29) and in 6-7 years age group was 7.43% (95% Cl: 5.75-9.10). The prevalence of asthma among girls, based on random effect model, was 6.30% (95% Cl: 4.97-7.61) and among boys, it was 8.91% (95% Cl: 6.80-11.04).

Conclusion: The prevalence of asthma in the Middle East is lower than most developed countries. However, there is not enough longitudinal data to estimate the trend over time. In order to have more accurate estimates and to provide evidence for proper planning, standard epidemiologic studies should be conducted in countries of the region.

Risk of developing major depression and bipolar disorder among adolescents with atopic diseases: A nationwide longitudinal study in Taiwan

BACKGROUNDS

Previous studies have found an increased prevalence of atopic diseases among patients with major depression and bipolar disorder. But the temporal association between atopic diseases in adolescence and the subsequent risk of developing mood disorders has been rarely investigated.

METHODS

Using the Taiwan National Health Insurance Research Databases, 5075 adolescents with atopic diseases (atopic cohort) and 44,729 without (non-atopic cohort) aged between 10 and 17 in 2000 were enrolled into our study and followed to the end of 2010. Subjects who developed major depression or bipolar disorder during the follow-up were identified.

RESULTS

The atopic cohort had an increased risk of developing major depression (HR: 2.45, 95% CI: 1.93~3.11) and bipolar disorder (HR: 2.51, 95% CI: 1.71~3.67) compared to the non-atopic cohort, with a dose-dependent relationship between having a greater number of atopic comorbidities and a greater likelihood of major depression (1 atopic disease: HR: 1.80, 95% CI: 1.29~2.50; 2 atopic comorbidities: HR: 2.42, 95% CI: 1.93~3.04;≥3 atopic comorbidities: HR: 3.79, 95% CI: 3.05~4.72) and bipolar disorder (HR: 1.40, 95% CI: 0.57~3.44; HR: 2.81, 95% CI: 1.68~4.68; HR: 3.02, 95% CI: 1.69~5.38).

DISCUSSION

Having atopic diseases in adolescence increased the risk of developing major depression and bipolar disorder in later life. Further studies may be required to clarify the underlying mechanism between atopy and mood disorders, and to investigate whether prompt intervention may decrease the risk of subsequent mood disorders.

Time-trend analysis of prevalence, incidence and traditional Chinese medicine use among children with asthma: a population-based study

BACKGROUND

This study determined annual prevalence and incidence trends of asthma among children in Taiwan from 2002 to 2008. Risk factors and traditional Chinese medicine (TCM) use were examined.

METHODS

A random sample was selected for a population-based study with a selection probability of 0.5 from all 3-18 years insurants. The annual prevalence and incidence of asthma were estimated according to age, sex, insurance premium and degree of urbanization.

RESULTS

The prevalence of asthma increased from 12.99% in 2002 to 16.86% in 2008. The increase was greatest in 2008, among boys, 11-15 years, ≥medium insurance premium, and high- and medium-density urban area. TCM use in asthma-prevalent children decreased from 1.16% in 2002 to 0.59% in 2008. The incidence fluctuated, ranging from 1.01% in 2002 to 1.49% in 2005. The highest was in 2005, among boys, 3-5 years, ≥medium insurance premium and high-density urban area. TCM use in asthma-incident children decreased from 3.59% in 2002 to 1.69% in 2008.

CONCLUSION

This study demonstrated a substantial increase in annual prevalence of asthma among children in Taiwan from 2002 to 2008. The incidence fluctuated. The TCM use showed a decreasing linear trend and was higher in incident than in prevalent cases.

Type 1 Diabetes and Increased Risk of Subsequent Asthma: A Nationwide Population-Based Cohort Study

The association between type 1 diabetes mellitus (T1DM) and asthma remains controversial and has led to new interest in these 2 disorders. The purpose of this study was to examine the associations among young people with T1DM and asthma and offer a clinical demonstration of the balance between Th1 and Th2 responses.We conducted a retrospective cohort study by using data from the National Health Insurance (NHI) system of Taiwan. The cohort consisted of 3545 T1DM cases and 14,180 controls established during the 1998 to 2011 period. Of the 3545 T1DM patients, 55.1% were girls and 26.5% were in the age group <8 years.The overall incidence of asthma was 47% higher in the T1DM cohort than in the control cohort (6.49 vs 4.42 per 1000 person-y), with an adjusted hazard ratio (HR) of 1.34 (95% confidence interval [CI] = 1.11-1.62). Moreover, T1DM patients who visited the emergency room (ER) more than twice for diabetes had a higher adjusted HR of 17.4 (95% CI = 12.9-23.6) of developing asthma. The adjusted HR of asthma was 38.6 (95% CI = 28.5-52.2) in T1DM patients who had been hospitalized more than twice for diabetes.We observed a significantly higher incidence of asthma in young patients with T1DM than in the general population. Among young people of T1DM with more ER visits or frequent hospitalization because of diabetes mellitus were associated with risk of asthma, may indicate that poor glycemic control significantly contributes to asthma risk.

Interaction of intercellular adhesion molecule 1 (ICAM1) polymorphisms and environmental tobacco smoke on childhood asthma

Asthma is a chronic disease that is particularly common in children. The association between polymorphisms of the gene encoding intercellular adhesion molecule 1 (ICAM1) and gene-environment interactions with childhood asthma has not been fully investigated. A cross-sectional study was undertaken to investigate these associations among children in Taiwan. The effects of two functional single-nucleotide polymorphisms (SNPs) of ICAM1, rs5491 (K56M) and rs5498 (K469E), and exposure to environmental tobacco smoke (ETS) were studied. Two hundred and eighteen asthmatic and 877 nonasthmatic children were recruited from elementary schools. It was found that the genetic effect of each SNP was modified by the other SNP and by exposure to ETS. The risk of asthma was higher for children carrying the rs5491 AT or TT genotypes and the rs5498 GG genotype (odds ratio = 1.68, 95% confidence interval 1.09–2.59) than for those with the rs5491 AA and rs5498 AA or AG genotypes (the reference group). The risk for the other two combinations of genotypes did not differ significantly from that of the reference group (p of interaction = 0.0063). The two studied ICAM1 SNPs were associated with childhood asthma among children exposed to ETS, but not among those without ETS exposure (p of interaction = 0.05 and 0.01 for rs5491 and rs5498, respectively). Both ICAM1 and ETS, and interactions between these two factors are likely to be involved in the development of asthma in childhood.

Association of area socioeconomic status with lung function in children

OBJECTIVE

The study investigates the association between area-level socioeconomic status (SES) and children's lung function.

METHODS

Participants were 3994 seventh grade students from the Taiwan Children Health Study living in 14 communities in Taiwan and were recruited in 2007. Area-level SES predictors were population size, occupation type, income and education level. Hierarchical linear models (HLM) were used to examine the effects of area-level SES on lung function, after accounting for area air pollution and individual SES (parental education and family income).

RESULTS

Areas with high income were independently associated with lower child lung function. The coefficients for log transformation of area tax per person in HLM were -47.8 (95% confidence interval (CI): -80.9, -14.8) in FEV(1), -43.8 (95% CI: -75.2, -12.5) in FVC, -93.4 (95% CI: -179.3, -7.5) in FEF(25-75) and -203.2 (95% CI: -349.1, -57.2) in PEF. All SES predictors influenced in the same direction and affected males more. The interaction of area tax per person with parental educational level was significant on PEF, suggesting significant association of greater parental education with lower lung function in children.

CONCLUSION

High area SES was inversely associated with lung function in Taiwanese children.

Body mass index may modify asthma prevalence among low-birth-weight children

Childhood asthma, a growing health concern, has been associated with low birth weight and elevated body mass index. This study tested the hypothesis that overweight and obese adolescents with a history of low birth weight are at even greater risk of developing asthma. A cohort of 75,871 junior high school students was screened for asthma during 1995-1996 in Taiwan. Birth weight and estimated gestational age were obtained from the birth registry. Logistic regression and simple regression analyses were adjusted for confounding variables. Asthma was more prevalent in those with birth weights below 3,000 g and higher adolescent body mass indexes. Furthermore, those with both characteristics were consistently most likely to have asthma. Whether the asthma diagnosis among low-birth-weight subjects was assigned by physicians or medical questionnaire, the risks were elevated for both overweight (physician diagnosis: odds ratio = 1.41; medical questionnaire: odds ratio = 1.25) and obese (physician diagnosis: odds ratio = 1.38; medical questionnaire: odds ratio = 1.47) boys as well as overweight (physician diagnosis: odds ratio = 1.63; medical questionnaire: odds ratio = 1.30) and obese (physician diagnosis: odds ratio = 1.44; medical questionnaire: odds ratio = 1.32) girls (P < 0.05). Low birth weight predisposes one to develop asthma, and excess body mass amplifies the risk. A sex difference was observed. This study suggests that prenatal care and nutritional counseling could reduce asthma prevalence.

Expression status of ribonucleotide reductase small subunits hRRM2/p53R2 as prognostic biomarkers in stage I and II non-small cell lung cancer

Overexpression of ribonucleotide reductase M2 (hRRM2) and p53-dependent RR small subunit (p53R2) has been correlated with tumor malignancy and progression in several types of cancer. The aim of this study was to determine the association of p53R2/hRRM2 expression with clinicopathological characteristics of stage I and II non-small cell lung cancer (NSCLC). Immunohistochemistry was conducted on a tissue array that included 92 samples. Correlations between hRRM2 and p53R2 expression and clinicopathological factors, recurrence/metastasis, and outcomes were analyzed. The analyses revealed that there was no correlation between p53R2 expression and clinicopathological factors; hRRM2 was only positively related to poor tumor differentiation (p=0.006). Regarding overall survival during the follow-up period, patients with p53R2+/hRRM2- tumors had the best outcomes (p<0.01). Multivariant Cox analysis revealed that p53R2 (risk=0.232, 95% CI=0.086-0.626, p=0.004) not only served as a prognostic biomarker to predict survival, but also as an independent biomarker to predict disease-free survival (risk=0.545, 95% CI=0.301-0.987, p=0.045) of patients with NSCLC. Therefore, we consider that the expression of p53R2 can be used not only as a biomarker for overall survival, but also as an indicator for tumor recurrence. Based on our finding, p53R2 expression seems more important than that of hRRM2 in prognosis of early-stage lung cancer.

Trends of allergic symptoms in school children: large-scale long-term consecutive cross-sectional studies in Osaka Prefecture, Japan

BACKGROUND

Trends in the prevalence rates of allergic symptoms in children have been discussed extensively, but it remains uncertain which symptoms increase or decrease over time owing to the lack of large-scale long-term consecutive cross-sectional studies performed on a representative population of children.

OBJECTIVE

To clarify the trends in the prevalence rates of allergic symptoms in Japanese children.

METHODS

Total population questionnaire surveys were conducted 15 times from 1975 to 2006 for all children attending public elementary schools in Osaka Prefecture, Japan, with the number of subjects ranging from 460,000 to 900,000. Parents of the children completed the questionnaire about allergic symptoms and other symptoms, including wheeze, physician-diagnosed atopic dermatitis, rhinitis, and itching eyes.

RESULTS

Response rates were consistently over 90%. The prevalence of wheezing was constant until 1983, then increased from 1983 until 1993, then stabilized at about 4.4%. The lifetime prevalence of atopic dermatitis increased to 24% by 1993, and then decreased. The prevalence of rhinitis increased to 25% by 2003, whereas the prevalence of non-seasonal symptoms plateaued from 1993 on at 11% and vernal symptoms increased. The prevalence of itching eyes continued to increase to 21% in 2006, and vernal symptoms increased sharply.

CONCLUSIONS

In Osaka Prefecture, Japan, the turning point when the prevalence of wheezing in schoolchildren had begun to increase was 1983. And the turning point when the increase in the prevalence of wheezing, atopic dermatitis, and non-seasonal allergic rhinitis turned to decrease or constant was 1993. The prevalence of rhinitis and itching eyes in spring was still increasing in 2006.

Associations of age, gender, and BMI with prevalence of allergic diseases in children: PATCH study

BACKGROUND

Little is known about the prevalence of allergic diseases in children of different ages. This study aimed to investigate the prevalence of allergic diseases and allergic sensitization in children over a wide age range, with emphasis on the influence of age, gender, and body mass index (BMI).

METHODS

In a cross-sectional study, we assessed 5351 Taiwanese children aged 4-18 years using an International Study of Asthma and Allergies in Childhood questionnaire, BMI, and total and specific serum immunoglobulin E.

RESULTS

Forty-eight percent were currently symptomatic for at least one of three allergic diseases. Prevalence of wheeze ever, current wheeze, and diagnosed asthma were 17.0%, 7.5%, and 9.8%, respectively; analogous features for rhinitis were 47.8%, 44.2%, and 39.8%. Allergic sensitization was very common (57.3%). Half of the children (50.6%) with current wheeze had not been diagnosed with asthma by physicians, whereas undiagnosed rates were 32.3% for rhinitis and 25.3% for eczema. The male-to-female prevalence ratios of current wheeze increased with age from <1 at 4-5 years, peaked at 10-11 years (2.24), then reversed to 0.57 at 16-18 years. Childhood wheezing tended to remit with age, but rhinitis and eczema were more persistent. Total immunoglobulin E levels increased with age until 14-15 years, and declined thereafter. Elevated BMI was associated with greater prevalence of wheezing and eczema, with no evidence of significant effect modification by either gender or age. Multivariate analyses revealed that younger age, boys, and obesity were significantly and independently associated with current wheezing in children (all p < .01).

CONCLUSIONS

The burden and co-morbidity of childhood allergies are substantial. There are striking age-dependent gender differences in asthma prevalence, exhibiting an inverted U-shaped curve for male-to-female prevalence ratios by age. Obesity is associated with a greater prevalence of asthma in children with no evidence of a significant modulation by either gender or age.

Gender-specific differences in effects of prenatal and postnatal environmental tobacco smoke exposure on respiratory symptoms in 23,474 children with and without allergic predisposition: results from 25 districts of northeast China

To assess the interaction of environmental tobacco smoke (ETS) exposure and allergic predisposition regarding respiratory health among Chinese children, a sample of 23,474 children (6-13 years old) was studied from 25 districts in Liaoning province, China. The results showed that children without allergic predisposition were more susceptible to ETS than children with allergic predisposition. Among children without allergic predisposition, ETS exposure was associated with more respiratory symptoms and diseases in boys than in girls; In utero ETS exposure was associated with history of asthma (OR, 1.86; 95% CI, 1.44-2.40) and current asthma (OR, 2.25; 95% CI, 1.48-3.44) only among boys without allergic predisposition. Among children with allergic predisposition, more associations between ETS exposure and respiratory symptoms and diseases were detected in girls. In conclusion, ETS exposure was more evident in boys without family atopy history and more associations were detected in girls with family atopy history.

[Risk factors and prevalence of asthma and rhinitis among primary school children in Lisbon]

AIMS

A cross-sectional study was carried out with the objective of identifying nutrition habits and housing conditions as risk factors for respiratory problems in schoolchildren in Lisbon.

MATERIAL AND METHODS

Between October and December 2008, parents of 900 students of the basic schools of Lisbon were invited to answer a questionnaire of the International Study of Asthma and Allergies in Childhood Program (ISAAC). The response rate was 40%. Logistic regression was used in the analysis of results.

RESULTS

The prevalence of asthma, allergic rhinitis and wheeze was 5.6%, 43.0% and 43.3%, respectively. Risk factors independently associated with asthma were wheezing attacks, and dry cough at night not related to common cold in the last 12 months. Wheezing crises were found to affect children daily activities. Risk factors for wheeze were hay fever and the presence of a pet at home. A risk factor for rhinitis was cough at night. The frequent consumption of egg was also associated with increased risk of rhinitis.

CONCLUSION

Contrarily to asthma, the prevalence of allergic rhinitis and wheeze increased in comparison with previous ISAAC studies. Wheezing attacks were associated with asthma and hay fever was identified as a risk factor of manifesting wheezing symptoms. Having pets at home was pointed out as a significant risk factor for rhinitis, but not smoking exposure, mould, plush toys, diet (except egg consumption), breastfeeding or other conditions.

Downregulation of caveolin-1 in a murine model of acute allergic airway disease

BACKGROUND

Airway remodeling refers to the structural changes in the airways of asthma. Caveolin-1 reduces cell growth and negatively regulates smooth muscle cell proliferation. The aim was to investigate lung caveolin-1 status in a murine model of acute allergic airway disease.

METHODS

Six- to eight-week-old female BALB/c mice were sensitized by intraperitoneal injections of phosphate-buffered saline or ovalbumin (OVA) and aluminium hydroxide on Days 0 and 14, challenged with aerosolized saline or OVA (1%) on Days 21-25, 28-32, and 35. The mice were killed 1 day after the last OVA/saline challenge. Serum OVA-specific immunoglobulin E (IgE) was measured by enzyme-linked immunosorbent assay. Peribronchial inflammation was quantified by morphometric analysis. Lung caveolin-1 and Type I collagen mRNA expression was determined by real-time reverse-transcription polymerase chain reaction. Total lung collagen was measured using Sircol Assay Kit.

RESULTS

Serum OVA-specific IgE levels were significantly elevated in OVA-challenged mice when compared with saline-challenged mice. Percentage of inflammatory cells in the bronchoalveolar lavage was significantly higher in the OVA-challenged animals. The animals' lungs that were sensitized and challenged with OVA contained large numbers of inflammatory cells concentrated near the airways and in the perivascular areas. The thickness of the bronchial epithelial layer and smooth muscle layer and the numbers of total inflammatory cells and eosinophils significantly increased in OVA-challenged mice. Caveolin-1 mRNA expression significantly decreased and Type I collagen mRNA expression significantly increased in the lung tissue of OVA-challenged mice.

CONCLUSION

These results suggest that caveolin-1 seems to be involved in the pathogenesis of airway remodeling of acute allergic airway disease.

A decrease in the prevalence and improved control of allergic conditions in 13- to 15-yr-old Maltese children (ISAAC)

The International Study of Asthma and Allergies in Childhood (ISAAC) has produced a reliable global map of childhood allergies through the use of a validated standardized questionnaire. Phase 1 of the study was carried out in the Maltese Islands in 1995 and repeated in 2002 in phase 3. To investigate the trends in prevalence and severity of childhood allergies in Maltese schoolchildren, in this article, we compare the data obtained from 4184 children, 13- to 15-yr-olds (88.7% response rate) in phase 1, to that of phase 3 when 4139 (90% response rate) children participated. The cumulative (27.9% vs. 27.4%: p=0.6) and current (16% vs. 14.6% p=0.08) prevalence rates of wheezing remained quite static but wheezers were more likely to be diagnosed with asthma in 2002 (11.1% vs. 14.1% p<0.0001). Along the 7 yrs, these asthmatics were better controlled with less wheezing attacks (p<0.01), less disturbed nights (p<0.05) and less acute severe episodes (p<0.05). Nasal problems were present in 52.7% of participants in 1995 and in 50.4% in 2002 (p<0.05), and 47.4% vs. 42.8% (p<0.0001) persisted with these symptoms and associated itchy eyes (29% vs. 21.8%: p<000001). Though prevalence decreased, the children were labelled as hayfever sufferers more often (32.3 vs. 40.7%: p<0.00001). Rhinitis symptoms seemed to interfere less with daily activities (p<0.01). In 2002, an itchy rash suggestive of eczema was also less present 'ever' (12.8% vs. 11.2%: p<0.05) or currently (10.1% vs. 8.5%: p<0.05) but again more likely to be diagnosed as eczema (p<0.001). This rash caused less sleepless nights in phase 3 of the study (p<0.05). These results indicate that asthma prevalence has reached a plateau between 1995 and 2002 while rhinitis and eczema are less common. All these allergic conditions are better controlled and more likely to be diagnosed in these schoolchildren by Maltese doctors in 2002 than in 1995.

Development of a nomogram for identification of asthma among adults in epidemiologic studies

BACKGROUND

The criteria used to identify persons with asthma in epidemiologic studies are varying and, depending on the method used, can be challenging and resource consuming.

OBJECTIVE

To develop a nomogram (scoring system) to identify adult patients with asthma using a combination of variables collected via a validated questionnaire.

METHODS

We studied the first 268 women aged 40 to 69 years in the Shanghai Women's Asthma and Allergy Study who reported signs and symptoms of asthma and underwent either methacholine challenge testing or test of reversibility during the asthma screening survey between 2003 and 2007. These women were defined as having definite asthma (n=106) or not (n=162). Multivariable logistic regression analysis was performed to develop a predictive model for identifying asthma using survey information alone.

RESULTS

Clinically relevant questions were used for the predictive multivariable logistic regression model and included the following: ever wheezing or whistling in the chest, current medication use for asthma, self-reported ever asthma, self-reported ever allergic rhinitis, family history of allergy, and age. The area under the receiver operating characteristic curve of the prediction model was 0.75 (95% confidence interval, 0.69-0.81). A nomogram was developed to assess the individual probability of asthma based on individually weighted variables in the predictive model.

CONCLUSIONS

In clinical or epidemiologic studies, this asthma nomogram could be used as a tool to assess the probability of asthma for an individual patient by incorporating asthma-related predictor variables obtained through a field questionnaire.

Advantages of video questionnaire in estimating asthma prevalence and risk factors for school children: findings from an asthma survey in American Indian youth

OBJECTIVES

The aims of the present study were to estimate the prevalence and risk factors of asthma among a sample of American Indian youth and to evaluate survey instruments used in determining asthma prevalence and risk factors.

METHODS

Three hundred and fifty-two adolescents aged 9 to 21 years enrolled in an Indian boarding school completed an asthma screening. The survey instruments were a written questionnaire and a video-illustrated questionnaire prepared from the International Study of Asthma and Allergies in Childhood (ISAAC), school health records, and a health questionnaire. Participants also underwent spirometry testing.

RESULTS

The prevalence of self-reported asthma varied from 12.7% to 13.4% depending upon the instrument used and the questions asked. A history of hay fever, respiratory infections, and family history of asthma were found to be risk factors for asthma by all instruments. Female gender and living on a reservation were significantly associated with asthma by some, but not all, instruments. Airway obstruction was highly associated with one asthma symptom (wheeze) shown in the video questionnaire. Associations for most risk factors with asthma were strongest for the video questionnaire.

CONCLUSIONS

The prevalence of self-reported asthma among these American Indian youth was similar to rates reported for other ethnic groups. The video-based questionnaire may be the most sensitive tool for identifying individuals at risk for asthma.

Is the prevalence of asthma declining? Systematic review of epidemiological studies

Asthma prevalence has increased very considerably in recent decades such that it is now one of the commonest chronic disorders in the world. Recent evidence from epidemiological studies, however, suggests that the prevalence of asthma may now be declining in many parts of the world, which, if true is important for health service planning and also because this offers the possibility of generating and testing new aetiological hypotheses. Our objective was to determine whether the prevalence of asthma is declining worldwide. We undertook a systematic search of EMBASE, Medline, Web of Science and Google Scholar, for high quality reports of cohort studies, repeat cross-sectional studies and analyses of routine healthcare datasets to examine international trends in asthma prevalence in children and adults for the period 1990-2008. There were 48 full reports of studies that satisfied our inclusion criteria. The large volume of data identified clearly indicate that there are, at present, no overall signs of a declining trend in asthma prevalence; on the contrary, asthma prevalence is in many parts of the world still increasing. The reductions in emergency healthcare utilization being reported in some economically developed countries most probably reflect improvements in quality of care. There remain major gaps in the literature on asthma trends in relation to Africa and parts of Asia. There is no overall global downward trend in the prevalence of asthma. Healthcare planners will for the foreseeable future, therefore, need to continue with high levels of anticipated expenditure in relation to provision of asthma care.

Indoor environmental risk factors and seasonal variation of childhood asthma

Seasonality of asthma may result from varying exposures. This cross-sectional study was designed to examine the relationship between indoor environmental factors and seasonal childhood asthma. Study subjects were participants from the International Study of Asthma and Allergies in Childhood (ISAAC) in 2004, a population-based surveillance, which included school children aged 6-15 yr in south Taiwan. Cases included 1725 children who experienced asthma symptoms in the past 12 months and the references consisted of 19,646 children who reportedly have no asthma history. By using a moving average and principal component analysis, asthmatic children were grouped into four asthma subtypes: winter, spring, summer/fall, and perennial. Multivariate logistic regression was used to evaluate the effect of indoor environmental factors on seasonality of childhood asthma. For all asthma prevalence, a peak occurred in the winter and a nadir appeared in summer. Contributing factors of asthma for children, regardless of seasonality, included younger age, parental atopy, maternal smoking during pregnancy, breast feeding, and perceived air pollution. After adjusted for salient risk factors, water damage was significantly associated with all subtypes of asthma. Presence of cockroaches was related to the summer/fall asthma (adjusted odds ratio [aOR] = 1.65, 95% confidence interval [CI] = 1.12-2.55). Visible mold on the walls was associated with an increased occurrence of winter and spring asthma (aOR = 1.53, 95% CI = 1.26-1.85 and aOR = 1.34, 95% CI = 1.10-1.62, respectively). Passive smoking was shown to be related to spring and summer/fall asthma. Water damage is a possible risk for childhood asthma year-round. Cockroaches and visible mold on the walls may play essential roles for seasonality of childhood asthma in Taiwan. Plausible mechanisms and allergic effects should be further determined. Elimination of these allergens is necessary to help prevent the development of asthma.

Prevalence of self-perceived allergic diseases and risk factors in Italian adolescents

The aim of the study was to assess the symptoms prevalence of allergic diseases in a population of 11-15 yr old schoolchildren, to evaluate the associations between asthma and other symptoms and identify risk factors for asthma, rhinitis and eczema syndromes. A sample of 481 students was studied using an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Prevalence of different kind of self-reported symptoms was calculated. Using a logistic regression approach, we tried to identify risk factors for three syndromes - rhinitis, eczema and asthma. The highest and the lowest prevalence rates of self-reported symptoms were recorded for rhinitis (43.6%) and for eczema (8.1%), respectively. The prevalence of asthma was 15.7%. Univariate analysis showed a mutual association between wheeze and rhinitis symptoms. Multivariate logistic regression model for eczema syndrome revealed female gender as a significant risk factor. The polytomic logistic multivariate regression revealed female gender and family history of allergy as significant risk factors for rhinitis syndrome only, and maternal smoking and familial allergy for rhinitis and asthma together. In particular, familial allergy yields a 400% higher chance of developing asthma and rhinitis together. The synergistic effect of familial allergy on rhinitis and asthma syndromes suggests the implementation of preventive measures in children with family history of these diseases.

Prevalence of asthma symptoms and atopic disorders in preschool children and the trend over a decade

OBJECTIVES

Over the last few decades, there have been substantial publications on the prevalence and trends of asthma in school-age children and adolescents. There has been a scarcity of reports on asthma prevalence and trends in preschool children. This study was performed to measure the prevalence of symptoms of asthma, allergic rhinitis, and eczema in preschool (4- and 5-year-old) children and the trend over a decade.

STUDY DESIGN

A cross-sectional questionnaire based survey using the International Study of Asthma and Allergy in Childhood (ISAAC) was performed on South Australian preschool children in 2006. The results were compared to a previous survey conducted in 1993.

RESULTS

The 12-month period prevalence of reported wheeze, allergic rhinitis, and eczema was 23.7%, 20.8%, and 18.8%, respectively. The prevalence of wheeze symptoms was higher in males than females. There was a decline in the prevalence of "wheeze in the last 12 months" (25.2% to 23.7%) and in "asthma ever" (22.5% to 19.0%, p < 0.05) from 1993 to 2006.

CONCLUSION

There is a burden in the symptoms of asthma, allergic rhinitis, and eczema in preschool children. There is a declining trend in the prevalence of "current wheeze" and "asthma ever" in South Australian preschool children over a decade.

Is the ebb of asthma due to the decline of allergic asthma? A prospective consultation-based study by the Swiss Sentinel Surveillance Network, 1999-2005

OBJECTIVE

There are conflicting views on time trends of asthma and atopy during the last 10-15 years. Additional confusion is caused by the term of asthma which is a unifying name for different phenotypes. Asthma has been a topic for investigation to the Swiss Sentinel Surveillance Network (SSSN) since 1989. The objective of the actual study was to determine the influence of the allergic and non-allergic components of asthma on time trends from 1999 to 2005.

METHODS

Primary care physicians participating in the SSSN were guided by diagnostic criteria for asthma. Rates of asthma episodes per 1000 consultations were calculated for all, for first and subsequent asthma episodes and for allergic and non-allergic asthma. Allergic asthma was defined as asthmatic manifestations in conjunction with eczema and/or hay fever. The smoothed time trend and its 95% confidence intervals were determined using generalized additive models with a loess smoother adjusting for seasonality.

RESULTS

Consultations for allergic asthma have decreased between 1999 and 2005. Looking at different age groups, asthma associated with hay fever was reported with decreasing frequency in all age groups, whereas when associated with eczema, the other used marker of allergic asthma, slightly increased among young children.

CONCLUSIONS

The decrease of consultations for asthma is most probably due to the allergic component of asthma. Diagnostic shift over time and ready available medications probably contributed to this phenomenon. Our findings indicate a real decline of allergic asthma. Practice recommendations. Consultations for asthma have decreased over recent years. The decrease of consultations for asthma is most probably due to the allergic component of asthma. Diagnostic shift over time and available medications probably contributed to this phenomenon. Strength of Recommendation Taxonomy (SORT) rating: strength of recommendation = C, level of evidence = 3.

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.

Prevalence of childhood allergic diseases in central Taiwan over the past 15 years

BACKGROUND

The prevalence of asthma, allergic rhinitis and atopic eczema in children from the developed and developing countries has been increasing.

METHODS

Three epidemiological surveys of the prevalence of bronchial asthma, allergic rhinitis and atopic eczema in schoolchildren in Taichung, located in central Taiwan, were conducted in 1987, 1994, and 2002. The first questionnaire was used before the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire was developed; the last two surveys were modified using ISAAC questionnaires.

RESULTS

A total of 37,801, 75,960, and 11,580 children were studied in 1987, 1994 and 2002, respectively. The prevalence of allergic diseases had increased in the past two decades. Results indicate that the prevalence of bronchial asthma had risen, from 2.19% in 1987, and 3.54% in 1994, to 6.99% in 2002. Regardless of sex, the prevalence of bronchial asthma decreased with increasing age. The prevalence of allergic rhinitis was 5.1% in 1987, 12.46% in 1987, and 27.59% in 2002, and the prevalence of atopic eczema was 1.10% in 1987, 1.88% in 1994, and 3.35% in 2002.

CONCLUSION

There has been a significant increase in the prevalence of bronchial asthma, allergic rhinitis and atopic dermatitis in Taichung schoolchildren from 1987 to 2002.

Effects of environmental tobacco smoke on respiratory health of boys and girls from kindergarten: results from 15 districts of northern China

The effects of childhood environmental tobacco smoke (ETS) exposure on respiratory symptoms were investigated in 6053 kindergarten-aged children residing in 15 districts of northern China. Responses to a self-administered questionnaire completed by parents of children from 30 kindergartens were used to ascertain children with persistent cough, persistent phlegm, asthma symptom, current asthma, wheeze and wheeze without asthma. In first 2 years ETS exposure and current ETS exposure were associated with increased prevalence of persistent cough, persistent phlegm, wheeze and wheeze without asthma. Among boys, ETS exposure was associated with more respiratory symptoms and diseases than in girls. ETS exposure during pregnancy was associated with asthma symptom [odds ratio (OR), 3.00; 95% confidence interval (CI): 1.28-7.03], current asthma (OR, 3.38; 95% CI: 1.25-9.14), persistent cough (OR, 1.64; 95% CI: 1.13-2.37), persistent phlegm (OR, 1.74; 95% CI: 1.01-3.01), wheeze (OR, 1.75; 95% CI: 1.15-2.68), and wheeze without asthma (OR, 1.46; 95% CI: 1.01-2.37) only among boys. In boys, the adjusted ORs for increased risk of asthma symptom and current asthma for household exposures (> or =10 cigarettes smoked per day vs. none smoked) during workday were 2.04 (95% CI: 1.01-3.89) and 2.76 (95% CI: 1.06-9.58), respectively. We conclude that ETS exposure increases the occurrence of respiratory symptoms and diseases during childhood. Boys may be more susceptible to ETS than girls.

PRACTICAL IMPLICATIONS

Environmental tobacco smoke (ETS) is a highly prevalent respiratory irritant. In agreement with previous cross-sectional studies, our study indicates that exposure to ETS may increase the occurrence of respiratory symptoms and diseases in children, and the association of ETS exposure and respiratory health of children increased in strength with number of cigarettes smoked inside the house per day during workday and day-off. Boys may be more susceptible to ETS than girls. These findings support the view that measures should be taken to reduce ETS exposure for children.