Yang-Ching Chen

Pathway from Central Obesity to Childhood Asthma. Physical Fitness and Sedentary Time Are Leading Factors

RATIONALE Available prospective studies of obesity and asthma have used only body mass index (BMI) as an indicator for adiposity; studies using detailed obesity measures are lacking, and the role of physical fitness level and sedentary time remains unexplored in the link between obesity and asthma. OBJECTIVES To compare various anthropometric measures of obesity in relation to childhood asthma, and to further characterize the interrelations among central obesity, physical fitness level, sedentary time, and asthma. METHODS The nationwide Taiwan Children Health Study followed 2,758 schoolchildren from fourth to sixth grade, annually collecting data regarding physical fitness, sedentary time, obesity measures (comprising body weight and height, abdominal and hip circumference, skin fold thickness, and body composition), asthma, and pulmonary function tests. The generalized estimating equation was used for 3 years of repeated measurements to analyze the interrelation among obesity, sedentary time, physical fitness level, and asthma; a structural equation model was used to explore the pathogenesis among these factors. Asthma incidence was analyzed during a 2-year follow-up among centrally obese and nonobese groups in baseline children without asthma. MEASUREMENTS AND MAIN RESULTS Central obesity most accurately predicts asthma. Low physical fitness levels and high screen time increase the risk of central obesity, which leads to asthma development. Obesity-related reduction in pulmonary function is a possible mechanism in the pathway from central obesity to asthma. CONCLUSIONS Central obesity measures should be incorporated in childhood asthma risk predictions. Children are encouraged to increase their physical fitness levels and reduce their sedentary time to prevent central obesity-related asthma.

Early-life indoor environmental exposures increase the risk of childhood asthma

We aim to explore the relationships between exposure to dampness, pets, and environmental tobacco smoke (ETS) early in life and asthma in Taiwanese children, and to discuss their links to early- and late-onset asthma. We conducted a 1:2 matched case-control study from the Taiwan Children Health Study, which was a nationwide study that recruited 12-to-14 year-old school children in 14 communities. The 579 mothers of the participants were interviewed by telephone about their childrens environmental exposures before they were 5 years old, including the in-utero period. Childhood asthma was associated with exposure to early life environmental factors, such as cockroaches (OR=2.16; 95% CI, 1.15-4.07), visible mould (OR=1.75; 95% CI, 1.15-2.67), mildewy odors (OR=5.04; 95% CI, 2.42-10.50), carpet (OR=2.36; 95% CI, 1.38-4.05), pets (OR=2.11; 95% CI, 1.20-3.72), and more than one hour of ETS per day (OR=1.93; 95% CI, 1.16-3.23). The ORs for mildewy odors, feather pillows, and ETS during early childhood were greater among children with late-onset asthma. Cockroaches, carpet, pets, and in-utero exposures to ETS affected the timing of early-onset asthma. Exposure to these factors led to dose-responsiveness in the risk of asthma. And the earlier exposures may trigger the earlier onset. Interventions in avoiding these environmental exposures are necessary for early-prevention of childhood asthma.

Environmental factors associated with overweight and obesity in taiwanese children.

BACKGROUND We explored the relationship among sociodemographic, behavioural, household environmental and perinatal factors, and risks of childhood overweight and obesity in Taiwan. METHODS A total of 7930 children aged 9 to 14 years were recruited from 14 randomly selected Taiwanese communities in 2007 and 2010. Height and weight were measured using standard protocols during school visits. Questionnaires that contained childrens family information, birth conditions, exercise habits and household environmental factors were answered by the parents. Associations between risk factors and childhood overweight and obesity were estimated through odds ratio and 95% confidence interval from mixed models. RESULTS In this cohort, 32.3% of the children were overweight and 17.5% were obese. Male gender, high birthweight, exposure to in utero maternal smoking and current exposure to household environmental tobacco smoke (stronger effect of maternal than paternal smoking) were positively associated with childhood overweight/obesity. In contrast, higher parental education level, number of siblings, active exercise habits and taking vitamins were associated with reduced risks of childhood obesity. Birthweight revealed a J-shaped relationship with the probability of childhood overweight/obesity. CONCLUSIONS This study uncovers several modifiable risk factors for childhood overweight and obesity, and parents are encouraged to provide an anti-obesity environment such as quitting smoking, controlling birthweight of child during pregnancy and building up exercise habits.

Associations between allergic diseases and attention deficit hyperactivity/oppositional defiant disorders in children

Background:We aim to investigate the detailed associations between allergic diseases with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) among children.Methods:Clinical information from 2,896 children enrolled in the Taiwan Children Health Study was obtained for analyses. Allergic diseases, including atopic dermatitis, asthma, and allergic rhinitis, have been evaluated based on the questions adjusted from International Study of Asthma and Allergies in Childhood. The Swanson, Nolan, and Pelham questionnaire was used to assess symptoms of ADHD and ODD. Symptoms of depression, stress, and poor sleep quality were evaluated as the interactive risk factors.Results:Children having symptoms of allergic diseases within the past 1 y were associated with having all dimensions of symptoms of ADHD and ODD. Children with ever having a physician-diagnosed atopic dermatitis were associated with inattentive and hyperactive–impulsive symptoms of ADHD. Ever diagnosed asthma was associated with ADHD and ODD. Ever diagnosed allergic rhinitis was associated with inattentive and combined symptoms of ADHD and ODD.Conclusion:Children with allergic diseases, such as atopic dermatitis, asthma, and allergic rhinitis, were associated with exhibiting ADHD and ODD.

Active smoking, environmental tobacco smoke and bronchitic symptoms among adolescents in Taiwan: A prospective cohort study

OBJECTIVE The study investigates the association between active smoking, exposure to environmental tobacco smoke (ETS) and the development of bronchitis and bronchitic symptoms among adolescents. METHODS A prospective cohort study was conducted with 4134 adolescents aged 12-14 from the Taiwan Children Health Study in 14 communities in Taiwan since 2007. Parents or guardians completed written questionnaires regarding demographic information, household ETS and respiratory symptoms at baseline. The adolescents themselves completed identical questionnaires on respiratory outcomes in the 2009 survey. Associations between active smoking, exposure to ETS and the 2-year incidence of respiratory outcomes were analyzed by multiple Poisson regression models, taking overdispersion into account. RESULTS Active smoking was associated with an increased risk of developing chronic cough and chronic phlegm. We found significant dose-response associations between the duration of smoking, the numbers of cigarettes and the onset of bronchitic symptoms. Exposure to ETS was a significant risk factor for the development of chronic cough. Among asthmatic adolescents, exposure to ETS was associated with an additional risk for the onset of chronic phlegm. CONCLUSION This study demonstrates that active smoking and exposure to ETS are associated with higher risks for developing bronchitic symptoms among adolescents.

Gestational Medication Use, Birth Conditions, and Early Postnatal Exposures for Childhood Asthma

Our aim is to explore (1) whether gestational medication use, mode of delivery, and early postnatal exposure correlate with childhood asthma, (2) the dose responsiveness of such exposure, and (3) their links to early- and late-onset asthma. We conducted a matched case-control study based on the Taiwan Children Health Study, which was a nationwide survey that recruited 12-to-14-year-old school children in 14 communities. 579 mothers of the participants were interviewed by telephone. Exclusive breastfeeding protected children from asthma. Notably, childhood asthma was significantly associated with maternal medication use during pregnancy, vacuum use during vaginal delivery, recurrent respiratory tract infections, hospitalization, main caregiver cared for other children, and early daycare attendance. Exposure to these factors led to dose responsiveness in relationships to asthma. Most of the exposures revealed a greater impact on early-onset asthma, except for vacuum use and daycare attendance.

Association of time-location patterns with urinary cotinine among asthmatic children under household environmental tobacco smoke exposure.

INTRODUCTION Environmental tobacco smoke (ETS) is a hazardous component of indoor air, and may increase the risk of respiratory diseases, atherosclerosis and otitis media in children. In this study, we explored the relationship between time inside the house, ETS exposure and urinary cotinine level, and also determined the association of time inside the house on asthma phenotypes when children exposed to ETS. METHODS A total of 222 asthmatic children and 205 non-asthmatic controls were recruited in the Genetic and Biomarker study for Childhood Asthma (GBCA). Structured questionnaires and time-location pattern questionnaires were administered by face-to-face interview. Urinary cotinine was measured by liquid chromatography tandem mass spectrometry (LC/MS/MS). The level of household ETS exposure was assessed using the cotinine/creatinine ratio (CCR). RESULTS In general, urinary cotinine and CCR were higher in subjects exposed to household ETS than those who never had ETS at home. A significant positive relationship was found between average time inside the house and urinary CCR in asthmatic children with current ETS at home (β=0.278, p=0.02). After adjustment for age and gender, average time inside the house was positively related to severe wheeze in asthmatic children with household ETS within 1 month (OR: 1.26, 95%: 1.02-1.64). CONCLUSIONS Our study suggests that the major source of ETS exposure for children is due to longer period of exposures among children living with adult smokers at home. Home-smoking restrictions that effectively prevent children from being exposed to ETS would be worthwhile.

Mediating pathways from central obesity to childhood asthma: a population-based longitudinal study

The mediating pathways linking obesity and asthma are largely unknown. We aimed to investigate the mediating pathways and to search for the most prominent pathological mechanism between central obesity and childhood asthma. In the Taiwan Children Health Study, we collected data on an open cohort of children aged 9–13 years. Childrens respiratory outcomes, atopic conditions, obesity measures and pulmonary function were surveyed annually between 2010 and 2012. Exhaled nitric oxide fraction concentrations were recorded in 2012. Generalised estimating equations and general linear models were used to examine the associations between central obesity, possible mediators and asthma. Structural equation models were applied to investigate the pathways that mediate the link between central obesity and asthma. Central obesity (waist-to-hip ratio) most accurately predicted childhood asthma. In the active asthma model, the percentage of mediation was 28.6% for pulmonary function, 18.1% for atopy and 5.7% for airway inflammation. The percentage of mediation for pulmonary function was 40.2% in the lifetime wheeze model. Pulmonary function was responsible for the greatest percentage of mediation among the three mediators in both models. Decline in pulmonary function is the most important pathway in central obesity related asthma. Pulmonary function screening should be applied to obese children for asthma risk prediction. Decline in pulmonary function is the most prominent pathological pathway from central obesity to childhood asthma http://ow.ly/4mJomZ

Associations between Respiratory Diseases and Dietary Patterns Derived by Factor Analysis and Reduced Rank Regression

Background/Aims: The study aims to identify childrens dietary patterns and explore the relationship between dietary patterns and respiratory diseases. Methods: Subjects were 2,397 fourth graders in 14 Taiwanese communities who participated in the Taiwan Children Health Study. This study is based on an evaluation of dietary patterns, performed from April until June 2011. Information pertaining to respiratory disease was obtained by The International Study of Asthma and Allergies in Childhood questionnaire, and dietary intake data obtained by food frequency questionnaire. Factor analysis and reduced rank regression (RRR) were both used to analyze dietary patterns. Results: Using factor analysis, it was found that children on a high-protein, high-fat, Western diet had a significantly higher risk of allergic rhinitis (OR 1.10, 95% CI 1.01-1.20). Lower ORs were noted for current wheezing, ever asthma and bronchitis in children eating a healthy diet than those on a high-protein, high-fat, Western diet. Using RRR, it was found that children on a high-protein, high-fat diet had significantly higher risks of allergic rhinitis (OR 1.17, 95% CI 1.07-1.27), current wheezing (OR 1.23, 95% CI 1.04-1.45) and bronchitis (OR 1.26, 95% CI 1.09-1.46). Conclusions: A diet rich in fat and protein may increase the risk of respiratory disease in children.

Causal relationships between adiposity and childhood asthma: bi-directional Mendelian Randomization analysis

Background/objectivesObesity and asthma are common chronic diseases and have been reported to be mutually causative. We investigated the causal direction of the relationship between adiposity and asthma using genetic markers as instrumental variables (IVs) in bi-directional Mendelian randomization (MR) analysis.Subjects/methodsWe used data from the Taiwan Children Health Study with 24 body mass index (BMI)-single-nucleotide polymorphisms (SNPs, combined into a weighted allelic score) and 16 asthma-SNPs (combined into two weighted allelic scores, separately for asthma inflammatory and antioxidative genes) to yield genetic IVs for adiposity and asthma, respectively.ResultsThe weighted allele score for BMI was strongly associated with adiposity (p = 2 × 10–16) and active asthma (p = 0.03). The two-stage least square regression risk ratio (RR) for the effect of BMI on asthma was 1.04 (95% confidence interval: 1.00–1.07, p = 0.03). Although the weighted asthma genetic scores were significantly associated with asthma (p = 8.4 × 10–3), no association was seen for genetically instrumented asthma with BMI using MR. Central obesity was the most accurate predictor of asthma. Adiposity showed higher causal effects on asthma in boys and children with non-atopic asthma. Sensitivity analysis for MR revealed no directional genetic pleiotropy effects. The causal effect RRs of BMI on asthma were 1.04, 1.08, and 1.03 for inverse-variance weighted, MR–Egger regression (slope), and weighted median methods, respectively, all in accordance with the MR estimates.ConclusionsHigh adiposity may lead to asthma, whereas the effects of asthma on adiposity accumulation are likely to be small.