Jungwoo Sohn

Air pollution as a risk factor for depressive episode in patients with cardiovascular disease, diabetes mellitus, or asthma

BACKGROUND There is currently insufficient evidence to confirm the effect of ambient air pollution on mental disorders, especially among susceptible populations. This study investigated the short-term effect of ambient air pollution on the risk of depressive episode and the effect modification across disease subpopulations. METHODS Subjects who visited the emergency department (ED) for depressive episode from 2005 to 2009 (n=4985) in Seoul, Republic of Korea were identified from medical claims data. We conducted a time-stratified case-crossover study using conditional logistic regression. Subgroup analyses were conducted after the subjects were stratified by underlying disease (cardiovascular disease, diabetes mellitus, chronic obstructive pulmonary disease, asthma, and depressive disorder). The risk was expressed as an odds ratio (OR) per 1 standard deviation of each air pollutant. RESULTS SO2, PM10, NO2, and CO were positively associated with ED visits for depressive episode. The maximum risk was observed in the distributed lag 0-3 model for PM10 (OR, 1.120; 95% confidence interval, 1.067-1.176). PM10, NO2, and CO significantly increased the risks of ED visits for depressive episode in subjects with either underlying cardiovascular disease, diabetes mellitus, asthma, or depressive disorder. LIMITATIONS Our data may include a misclassification bias due to the validity of a diagnosis determined from medical services utilization data. CONCLUSIONS SO2, PM10, NO2, and CO significantly increased the risk of ED visits for depressive episode, especially among individuals with pre-existing cardiovascular disease, diabetes mellitus, or asthma.

Changes in the Practice of Coronary Revascularization between 2006 and 2010 in the Republic of Korea

Purpose Evidence suggests that technological innovations and reimbursement schemes of the National Health Insurance Service may have impacted the management of coronary artery disease. Thus, we investigated changes in the practice patterns of coronary revascularization. Materials and Methods Revascularization and in-hospital mortality among Koreans ≥20 years old were identified from medical claims filed between 2006 and 2010. The age- and sex-standardized procedure rate per 100000 person-years was calculated directly from the distribution of the 2008 Korean population. Results The coronary revascularization rate increased from 116.1 (95% confidence interval, 114.9-117.2) in 2006 to 131.0 (129.9-132.1) in 2010. Compared to the rate ratios in 2006, the rate ratios for percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in 2010 were 1.16 (1.15-1.17) and 0.80 (0.76-0.84), respectively. Among patients who received PCI, the percentage with drug-eluting stents increased from 89.1% in 2006 to 93.0% in 2010. In-hospital mortality rates from PCI significantly increased during the study period (p=0.03), whereas those from CABG significantly decreased (p=0.01). The in-hospital mortality rates for PCI and CABG were higher in elderly and female patients and at the lowest-volume hospitals. Conclusion The annual volume of coronary revascularization continuously increased between 2006 and 2010 in Korea, although this trend differed according to procedure type. A high percentage of drug-eluting stent procedures and a high rate of in-hospital mortality at low-volume hospitals were noted.

Ambient ozone concentration and emergency department visits for panic attacks

The effect of ambient air pollution on panic disorder in the general population has not yet been thoroughly elucidated, although the occurrence of panic disorder in workers exposed to organic solvents has been reported previously. We investigated the association of ambient air pollution with the risk of panic attack-related emergency department visits. Using health insurance claims, we collected data from emergency department visits for panic attacks in Seoul, Republic of Korea (2005-2009). Daily air pollutant concentrations were obtained using automatic monitoring system data. We conducted a time-series study using a generalized additive model with Poisson distribution, which included spline variables (date of visit, daily mean temperature, and relative humidity) and parametric variables (daily mean air pollutant concentration, national holiday, and day of the week). In addition to single lag models (lag1 to lag3), cumulative lag models (lag0-1 to lag0-3) were constructed using moving-average concentrations on the days leading up to the visit. The risk was expressed as relative risk (RR) per one standard deviation of each air pollutant and its 95% confidence interval (95% CI). A total of 2320 emergency department visits for panic attacks were observed during the study period. The adjusted RR of panic attack-related emergency department visits was 1.051 (95% CI, 1.014-1.090) for same-day exposure to ozone. In cumulative models, adjusted RRs were 1.068 (1.029-1.107) in lag0-2 and 1.074 (1.035-1.114) in lag0-3. The ambient ozone concentration was significantly associated with emergency department visits for panic attacks.

Elevation of serum aminotransferase levels and future risk of death from external causes: a prospective cohort study in Korea

Purpose The association between liver enzymes and death from external causes has not been examined. We investigated the association between serum aminotransferase levels and external-cause mortality in a large prospective cohort study. Materials and Methods A total of 142322 subjects of 35-59 years of age who completed baseline examinations in 1990 and 1992 were enrolled. Mortalities were identified using death certificates. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were categorized into quintiles. Sub-distribution hazards ratios and 95% confidence intervals (CIs) were estimated using a competing risks regression model in which deaths from other causes were treated as competing risks. Results Of 8808 deaths, 1111 (12.6%) were due to external causes. Injury accounted for 256 deaths, and suicide accounted for 255. After adjusting for covariates, elevated ALT and AST were significantly associated with an increased risk of all external-cause mortalities, as well as suicide and injury. Sub-distribution hazards ratios (95% CIs) of the highest versus the lowest quintiles of serum ALT and AST were, respectively, 1.57 (1.26-1.95) and 1.45 (1.20-1.76) for all external causes, 2.73 (1.68-4.46) and 1.75 (1.15-2.66) for suicide, and 1.79 (1.10-2.90) and 1.85 (1.21-2.82) for injury. The risk of external-cause mortality was also significantly higher in the fourth quintile of ALT (21.6-27.5 IU/L) than in its first quintile. Conclusion Elevated aminotransferase levels, even within the normal range, were significantly associated with increased risk of all external-cause mortalities, including suicide, and injury.

YIA 02-02 LONG-TERM EFFECTS OF FINE PARTICULATE MATTER EXPOSURES ON MAJOR ADVERSE CARDIOVASCULAR EVENTS.

Objective: Epidemiological studies have been published acute or chronic adverse association between ambient particulate matter and cardiovascular/respiratory diseases. Recently, there has been increased interest in investigating the role of fine particulate matter on major adverse cardiovascular event (MACE). For the long-term effects, the external validity of studies has rarely been satisfied due to the representativeness of cohorts. The aim of this study was to investigate the potential impact of fine particulate matter long-term exposure on MACE, defined as time to incidence of acute myocardial infarction, ischemic stroke, hemorrhagic stroke, or death due to cardiovascular cause. Design and Method: We analyzed the effects of fine particulate matter on first hospital diagnosis for MACE among nationwide representative cohort of 1,025,340 participants, or 2% of the National Health Insurance Service enrollees in Korea (2002–2013). For participants who live in Seoul, a Cox proportional hazards model was used with adjustment for age, sex, income, insurance type, and past history. Annual mean concentration was calculated with annual 25 district-wide measurements from 2002 to 2013. Results: We followed approximately 12 years for 99,038 subjects (13,151 subjects with hypertension and 85,887 participants without hypertension) and observed significant associations of long-term fine particulate matter exposure with 5,662 MACE events. Specifically, estimated hazard ratio was 1.015 (95% CI: 1.004–1.027) for MACE per 1 &mgr;g/m3 increase in fine particulate matter exposure. Hazard ratio among hypertension patients was not statistically significant; 1.004 (95% CI 0.988–1.020) and that among participants without hypertension was 1.026 (95% 1.010–1.042). Conclusions: To the best of our knowledge, this is the first study to investigate the effect modification, by hypertension past history, in the chronic effect of fine particulate matter exposure on MACE incidence. Findings provide the basis for public health implications that long-term exposures could be crucial to cardiovascular event.

Medical care expenditure in suicides from non-illness-related causes.

Objectives: Several epidemiological studies on medical care utilization prior to suicide have considered the motivation of suicide, but focused on the influence of physical illnesses. Medical care expenditure in suicide completers with non-illness-related causes has not been investigated. Methods: Suicides motivated by non-illness-related factors were identified using the investigator’s note from the National Police Agency, which was then linked to the Health Insurance Review and Assessment data. We investigated the medical care expenditures of cases one year prior to committing suicide and conducted a case-control study using conditional logistic regression analysis after adjusting for age, gender, area of residence, and socioeconomic status. Results: Among the 4515 suicides motivated by non-illness-related causes, medical care expenditures increased in only the last 3 months prior to suicide in the adolescent group. In the younger group, the proportion of total medical expenditure for external injuries was higher than that in the older groups. Conditional logistic regression analysis showed significant associations with being a suicide completer and having a rural residence, low socioeconomic status, and high medical care expenditure. After stratification into the four age groups, a significant positive association with medical care expenditures and being a suicide completer was found in the adolescent and young adult groups, but no significant results were found in the elderly groups for both men and women. Conclusions: Younger adults who committed suicide motivated by non-illness-related causes had a higher proportion of external injuries and more medical care expenditures than their controls did. This reinforces the notion that suicide prevention strategies for young people with suicidal risk factors are needed.

Effect of Socioeconomic Status and Underlying Disease on the Association between Ambient Temperature and Ischemic Stroke

Purpose Inconsistent findings have been reported regarding the effect of ambient temperature on ischemic stroke. Furthermore, little is known about how underlying disease and low socioeconomic status influence the association. We, therefore, investigated the relationship between ambient temperature and emergency department (ED) visits for ischemic stroke, and aimed to identify susceptible populations. Materials and Methods Using medical claims data, we identified ED visits for ischemic stroke during 2005–2009 in Seoul, Korea. We conducted piecewise linear regression analyses to find optimum ambient temperature thresholds in summer and winter, and estimated the relative risks (RR) and 95% confidence intervals (CI) per a 1℃ increase in temperature above/below the thresholds, adjusting for relative humidity, holidays, day of the week, and air pollutant levels. Results There were 63564 ED visits for ischemic stroke. In summer, the risk of ED visits for ischemic stroke was not significant, with the threshold at 26.8℃. However, the RRs were 1.055 (95% CI, 1.006–1.106) above 25.0℃ in medical aid beneficiaries and 1.044 (1.007–1.082) above 25.8℃ in patients with diabetes. In winter, the risk of ED visits for ischemic stroke significantly increased as the temperature decreased above the threshold at 7.2℃. This inverse association was significant also in patients with hypertension and diabetes mellitus above threshold temperatures. Conclusion Ambient temperature increases above a threshold were positively associated with ED visits for ischemic stroke in patients with diabetes and medical aid beneficiaries in summer. In winter, temperature, to a point, and ischemic stroke visits were inversely associated.

Geographical variations and influential factors in prevalence of cardiometabolic diseases in South Korea

Geographical variations and influential factors of disease prevalence are crucial information enabling optimal allocation of limited medical resources and prioritization of appropriate treatments for each regional unit. The purpose of this study was to explore the geographical variations and influential factors of cardiometabolic disease prevalence with respect to 230 administrative districts in South Korea. Global Moran’s I was calculated to determine whether the standardized prevalences of cardiometabolic diseases (hypertension, stroke, and diabetes mellitus) were spatially clustered. The CART algorithm was then applied to generate decision tree models that could extract the diseases’ regional influential factors from among 101 demographic, economic, and public health data variables. Finally, the accuracies of the resulting model–hypertension (67.4%), stroke (62.2%), and diabetes mellitus (56.5%)–were assessed by ten-fold cross-validation. Marriage rate was the main determinant of geographic variation in hypertension and stroke prevalence, which has the possibility that married life could have positive effects in lowering disease risks. Additionally, stress-related variables were extracted as factors positively associated with hypertension and stroke. In the opposite way, the wealth status of a region was found to have an influence on the prevalences of stroke and diabetes mellitus. This study suggested a framework for provision of novel insights into the regional characteristics of diseases and the corresponding influential factors. The results of the study are anticipated to provide valuable information for public health practitioners’ cost-effective disease management and to facilitate primary intervention and mitigation efforts in response to regional disease outbreaks.

THE ASSOCIATION OF URINARY NAPHTHOL LEVEL AND STRUCTURAL CHANGE OF THE BRAIN-BRAIN CORTICAL THINNING AND VENTRICULAR ENLARGEMENT: A CROSS-SECTIONAL STUDY

baseline MCI and over two years of follow-up (N1⁄4601), we selected all who reverted to NC at least once, and having additional follow-up after reversion. Groups were compared using parametric and nonparametric tests where appropriate, on clinical (age, education, gender, APOE genotype, GDS), cognitive (MMSE, RAVLT total recall) and imaging markers (PET amyloid, PET FDG, hippocampal volume, MRI white matter hyperintensities). We evaluated biomarker abnormality proportions, using Chi-square tests. Results: Of the 65 (11% from the total MCI sample) individuals with MCI who reverted to NC, 53 (82%) had additional follow-up available. At last diagnosis, 37 (70%) subjects remained cognitively normal, while 13 (24%) had converted to MCI, and 3 (6%) to dementia. Compared to those with persistent normal cognition at follow-up, those who declined were older (mean1⁄47368 years vs 6867 years; p1⁄40.04), had higher amyloid burden (mean SUVR 1.2460.21 vs 1.0960.15; p1⁄40.01), and tended to have less years of education, lower glucose metabolism and smaller hippocampal volume (table 1). Conclusions: The MCI reversion rate to normal cognition was comparable to memory clinic studies. The majority of MCI reverters remained cognitively normal. Those who progressed to MCI or dementia were older age and had more abnormal AD biomarkers. MCI reverters without any signals of neurodegeneration may not be at increased risk for dementia. These results imply that biomarkers may aid in the prognosis of reverting MCI. References: 1. Aerts et al. 2017. Neurology; 2. Canevelli et al. 2016. JAMDA.

AMBIENT AIR POLLUTION ASSOCIATED WITH BRAIN CORTICAL THINNING: A CROSS-SECTIONAL STUDY IN A COMMUNITY-BASED COHORT

P2-595 AMBIENTAIR POLLUTION ASSOCIATED WITH BRAIN CORTICALTHINNING: A CROSS-SECTIONAL STUDY IN A COMMUNITY-BASED COHORT Jaelim Cho, Jungwoo Sohn, Juhwan Noh, Seong-Kyung Cho, Jee Eun Choi, Hyunmee Kim, Woojin Kim, Heeseon Jang, Changsoo Kim, University of Auckland, Auckland, New Zealand; Institute of Human Complexity and Systems Science, Yonsei University, Incheon, South Korea; Yonsei University College of Medicine, Seoul, South Korea. Contact e-mail: chojael@gmail.com