Juhwan Noh

Prevalence of Comorbidity among People with Hypertension: The Korea National Health and Nutrition Examination Survey 2007-2013.

Background and Objectives Joint National Committee guidelines attempt to vary treatment recommendations for patients based on considerations of their comorbidities. The aim of the present study is to estimate the age-standardized prevalence of common comorbidities among Korean hypertension patients. Subjects and Methods We analyzed the Korea National Health and Nutrition Examination Survey from 2007 to 2013. Among the 58423 participants, 30092 adults, aged ≥30 yrs who completed a health examination and interview survey, were selected. The survey procedures were used to estimate weighted prevalence and odds ratios for 8 comorbidities, including obesity, diabetes mellitus, dyslipidemia, cardiovascular disease, chronic kidney disease, and thyroid disease. Results Most chronic conditions were more prevalent in adults with hypertension than in those without hypertension. Common comorbidities were obesity (60.1%), dyslipidemia (57.6%), and impaired fasting glucose (45.1%). Hypertensive patients with two or more comorbid diseases were 42.2% and those with three or more diseases were 17.7%. The age- and sex-specific prevalence of three or more comorbid diseases among male hypertension patients was significantly higher than those patients in the 30-59 (p<0.05) age group. Conclusion Comorbidity is highly prevalent in Korean patients with hypertension.

High dietary phosphorus density is a risk factor for incident chronic kidney disease development in diabetic subjects: a community-based prospective cohort study

Background: High serum phosphorus concentrations are associated with an increased risk of cardiovascular disease and progression of chronic kidney disease (CKD). However, the relation between dietary phosphorus intake and CKD development has not been well evaluated.Objective: In this study, we investigated the impact of dietary phosphorus density on the development of incident CKD in a cohort of subjects with normal renal function.Design: Data were retrieved from the Korean Genome and Epidemiology Study, a prospective community-based cohort study. The study cohort consisted of subjects aged 40-69 y, who were followed up biennially from 2001 to 2014. A total of 873 subjects with diabetes mellitus (DM) and 5846 subjects without DM (non-DM) were included in the final analysis. The primary endpoint was incident CKD, defined as a composite of estimated glomerular filtration rate <60 mL · min-1 · 1.73 m-2 and/or the development of proteinuria.Results: In the DM and non-DM groups, the mean ages of the participants were 55.6 ± 8.7 and 51.4 ± 8.6 y, the numbers of male subjects were 454 (52.0%) and 2784 (47.6%), and the mean estimated glomerular filtration rates were 91.6 ± 14.0 and 94.5 ± 14.0 mL · min-1 · 1.73 m-2, respectively. The mean values of dietary phosphorus density, defined as the ratio of a single-day dietary phosphorus amount to the total daily calorie intake, were 0.51 ± 0.08 mg/kcal in the DM group and 0.51 ± 0.07 mg/kcal in the non-DM group. During the follow-up, CKD newly developed in 283 (32.4%) and 792 subjects (13.5%) in the DM and non-DM groups, respectively. When the subjects were divided into quartiles according to the dietary phosphorus density in each group, the highest quartile was significantly associated with the development of incident CKD by multiple Cox proportional hazard analysis in the DM group (P = 0.02) but not in the non-DM group (P = 0.72).Conclusions: High dietary phosphorus density is associated with an increased risk of CKD development in DM patients with normal renal function. The causality in this association needs to be tested in a randomized controlled trial.

Warfarin Use in Patients with Atrial Fibrillation Undergoing Hemodialysis: A Nationwide Population-Based Study

Background and Purpose— The aim of this study is to elucidate the effects of warfarin use in patients with atrial fibrillation undergoing dialysis using a population-based Korean registry. Methods— Data were extracted from the Health Insurance Review and Assessment Service, which is a nationwide, mandatory social insurance database of all Korean citizens enrolled in the National Health Information Service between 2009 and 2013. Thromboembolic and hemorrhagic outcomes were analyzed according to warfarin use. Overall and propensity score–matched cohorts were analyzed by Cox proportional hazards models. Results— Among 9974 hemodialysis patients with atrial fibrillation, the mean age was 66.6±12.2 years, 5806 (58.2%) were men, and 2921 (29.3%) used warfarin. After propensity score matching to adjust for all described baseline differences, 5548 subjects remained, and differences in baseline variables were distributed equally between warfarin users and nonusers. During a mean follow-up duration of 15.9±11.1 months, ischemic and hemorrhagic stroke occurred in 678 (6.8%) and 227 (2.3%) patients, respectively. In a multiple Cox model, warfarin use was significantly associated with an increased risk of hemorrhagic stroke (hazard ratio, 1.44; 95% confidence interval, 1.09–1.91; P=0.010) in the overall cohort. Furthermore, a significant relationship between warfarin use and hemorrhagic stroke was found in propensity-matched subjects (hazard ratio, 1.56; 95% confidence interval, 1.10–2.22; P=0.013). However, the ratios for ischemic stroke were not significantly different in either the propensity-matched (hazard ratio, 0.95; 95% confidence interval, 0.78–1.15; P=0.569) or overall cohort (hazard ratio, 1.06; 95% confidence interval, 0.90–1.26; P=0.470). Conclusions— Our findings suggest that warfarin should be used carefully in hemodialysis patients, given the higher risk of hemorrhagic events and the lack of ability to prevent thromboembolic complications.

High and low sodium intakes are associated with incident chronic kidney disease in patients with normal renal function and hypertension

The association between salt intake and renal outcome in subjects with preserved kidney function remains unclear. Here we evaluated the effect of sodium intake on the development of chronic kidney disease (CKD) in a prospective cohort of people with normal renal function. Data were obtained from the Korean Genome and Epidemiology Study, a prospective community-based cohort study while sodium intake was estimated by a 24-hour dietary recall Food Frequency Questionnaire. A total of 3,106 individuals with and 4,871 patients without hypertension were analyzed with a primary end point of CKD development [a composite of estimated glomerular filtration rate (eGFR) under 60 mL/min/1.73 m2 and/or development of proteinuria during follow-up]. The median ages were 55 and 47 years, the proportions of males 50.9% and 46.3%, and the median eGFR 92 and 96 mL/min/1.73 m2 in individuals with and without hypertension, respectively. During a median follow-up of 123 months in individuals with hypertension and 140 months in those without hypertension, CKD developed in 27.8% and 16.5%, respectively. After adjusting for confounders, multiple Cox models indicated that the risk of CKD development was significantly higher in people with hypertension who consumed less than 2.08 g/day or over 4.03 g/day sodium than in those who consumed between 2.93-4.03 g/day sodium. However, there was no significant difference in the incident CKD risk among each quartile of people without hypertension. Thus, both high and low sodium intakes were associated with increased risk for CKD, but this relationship was only observed in people with hypertension.

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.

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

EFFECT MODIFICATIONS OF THE ASSOCIATION BETWEEN SERUM MERCURY LEVEL AND MILD COGNITIVE IMPAIRMENT BY SMOKING STATUS

P3-540 EFFECT MODIFICATIONS OF THE ASSOCIATION BETWEEN SERUM MERCURY LEVEL AND MILD COGNITIVE IMPAIRMENT BY SMOKING STATUS Juhwan Noh, Jaelim Cho, Seong-Kyung Cho, Jee Eun Choi, Eunju Lee, Changsoo Kim, Yonsei University College ofMedicine, Seoul, Republic of South Korea; Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom. Contact e-mail: njuhwan@yuhs.ac