Hwan Cheol Kim

Interaction Between Bronchiolitis Diagnosed Before 2 Years of Age and Socio-Economic Status for Bronchial Hyperreactivity

Objects The prevalence of asthma has increased in recent decades globally. The objective of the present study is to elucidate whether hospitalization for bronchiolitis in infancy and low socioeconomic status interact for bronchial hyperreactivity during teenage years. Method We studied 522 children age 13-14 years attending schools in rural and urban areas to investigate the risk factors for bronchial hyperreactivity (BHR), defined as a provocation concentration of methacholine that causes a decrease of 20% (PC20) in forced expiratory volume within 1 second. Clinical examination, skin prick test, spirometry, and methacholine challenge were performed on all study subjects, who provided written consent. We used multivariate logistic regression to investigate the risk factors for BHR, and analyze the interaction between hospitalization for bronchiolitis in infancy and low socioeconomic status. Results Forty-six (10.3%) positive BHR cases were identified. In the multivariate logistic analysis, as independent predictors of BHR, adjusted odds ratio of bronchiolitis diagnosed before 2 years of age in low income families was 13.7 (95% confidence interval, 1.4 to 135.0), compared to reference group, controlling for age, gender, parental allergy history, skin prick test, and environmental tobacco smoke (ETS) exposure. Interaction was observed between bronchiolitis before 2 years old and low socioeconomic status on childrens bronchial hyperreactivity (p-interaction=0.025). Conclusions This study showed that bronchiolitis diagnosed before 2 years of age and low socioeconomic status interacted on childrens bronchial hyperreactivity. Prevention of acute respiratory infection in early childhood in low socioeconomic status is important to prevent BHR as a precursor of asthma.

Associations between Ambient Particulate Matter and Nitrogen Dioxide and Chronic Obstructive Pulmonary Diseases in Adults and Effect Modification by Demographic and Lifestyle Factors

This study was undertaken to investigate the associations between chronic exposure to particulate matter of medium aerodynamic diameter ≤10 or ≤2.5 µm (PM10 or PM2.5) and nitrogen dioxide (NO2) levels and lung function and to examine a possible change in these relationships by demographic and lifestyle factors. Chronic obstructive pulmonary disease (COPD) was defined using the Global Initiative for COPD criteria (forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) of <70%). Associations of lung function and COPD with PM10 or PM2.5 or NO2 were examined using linear and logistic regression analyses among 1264 Korean adults. The highest tertiles of PM2.5 (≥37.1 μg/m3) and NO2 (≥53.8 μg/m3) exposure were significantly associated with COPD (highest versus lowest tertile of PM2.5: adjusted odds ratio (OR) = 1.79, 95% CI: 1.02–3.13; highest versus lowest tertile of NO2: adjusted OR = 1.83, 95% CI: 1.04–3.21). A 10 μg/m3 increase in PM10 concentration was associated with a 1.85 L (95% CI –3.65 to –0.05) decrease in FEV1 and a 1.73 L (95% CI –3.35 to –0.12) decrease in FVC, with the strongest negative association among older people and those with less education. Reduced lung function was associated with PM2.5 exposure in subjects with no physical activity. This study provides evidence that exposure to ambient air pollution has adverse effects on lung function in adults.

Necessity for a National Carcinogen List in Korea, Based on International Harmonization

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean governments efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.