PURPOSE: The pollen calendar is the simplest forecasting method for pollen concentrations. As pollen concentrations are liable to seasonal variations due to alterations in climate and land-use, it is necessary to update the pollen calendar using recent data. To attenuate the impact of considerable temporal and spatial variability in pollen concentrations on the pollen calendar, it is essential to employ a new methodology for its creation.METHODS: A pollen calendar was produced in Korea using data from recent observations, and a new method for creating the calendar was proposed, considering both risk levels and temporal resolution of pollen concentrations. A probability distribution was used for smoothing concentrations and determining risk levels. Airborne pollen grains were collected between 2007 and 2017 at 8 stations; 13 allergenic pollens, including those of alder, Japanese cedar, birch, hazelnut, oak, elm, pine, ginkgo, chestnut, grasses, ragweed, mugwort and Japanese hop, were identified from the collected grains.RESULTS: The concentrations of each pollen depend on locations and seasons due to large variability in species distribution and their environmental condition. In the descending order of concentration, pine, oak and Japanese hop pollens were found to be the most common in Korea. The pollen concentrations were high in spring and autumn, and those of oak and Japanese hop were probably the most common cause of allergy symptoms in spring and autumn, respectively. High Japanese cedar pollen counts were observed in Jeju, while moderate concentrations were in Jeonju, Gwangju and Busan.CONCLUSIONS: A new methodology for the creation of a pollen calendar was developed to attenuate the impact of large temporal and spatial variability in pollen concentrations. This revised calendar should be available to the public and allergic patients to prevent aggravation of pollen allergy.
Alnus ; Ambrosia ; Artemisia ; Asian Continental Ancestry Group ; Betula ; Busan ; Climate ; Corylus ; Cryptomeria ; Forecasting ; Ginkgo biloba ; Gwangju ; Humans ; Hypersensitivity ; Jeollabuk-do ; Korea ; Methods ; Poaceae ; Pollen ; Rhinitis, Allergic, Seasonal ; Seasons

BACKGROUND AND OBJECTIVES: Although anticoagulation with warfarin is recommended as an international normalized ratio (INR) of prothrombin time between 2.0 and 3.0 and mean time in the therapeutic range (TTR) ≥70%, little has been proven that universal criteria might be suitable in Korean atrial fibrillation (AF) patients.METHODS: We analyzed 710 patients with non-valvular AF who took warfarin. INR value and clinical outcomes were assessed during 2-year follow-up. Intensity of anticoagulation was assessed as mean INR value and TTR according to target INR range. Primary net-clinical outcome was defined as the composite of new-onset stroke and major bleeding. Secondary net-clinical outcome was defined as the composite of new-onset stroke, major bleeding and death.RESULTS: Thromboembolism was significantly decreased when mean INR was over 1.6. Major bleeding was significantly decreased when TTR was over 70% and mean INR was less than 2.6. Mean INR 1.6–2.6 significantly reduced thromboembolism (adjusted hazard ratio [HR], 0.40; 95% confidence interval [CI], 0.19–0.85), major bleeding (HR, 0.43; 95% CI, 0.23–0.81), primary (HR, 0.50; 95% CI, 0.29–0.84) and secondary (HR, 0.45; 95% CI, 0.28–0.74) net-clinical outcomes, whereas mean INR 2.0–3.0 did not. Simultaneous satisfaction of mean INR 1.6–2.6 and TTR ≥70% was associated with significant risk reduction of major bleeding, primary and secondary net-clinical outcomes.CONCLUSIONS: Mean INR 1.6–2.6 was better than mean INR 2.0–3.0 for the prevention of thromboembolism and major bleeding. However, INR 1.6–2.6 and TTR ≥70% had similar clinical outcomes to INR 2.0–3.0 and TTR ≥70% in Korean patients with non-valvular AF.
Atrial Fibrillation ; Follow-Up Studies ; Hemorrhage ; Humans ; International Normalized Ratio ; Prothrombin Time ; Risk Reduction Behavior ; Stroke ; Thromboembolism ; Warfarin

BACKGROUND AND OBJECTIVES: There is a paucity of data regarding the benefit of clopidogrel monotherapy after dual antiplatelet therapy (DAPT) in patients treated with drug-eluting stents (DES). This study compared outcome between clopidogrel versus aspirin as monotherapy after DES for acute myocardial infarction (MI).METHODS: From Korea Acute Myocardial Infarction Registry-National Institute of Health database, 1,819 patients treated with DES who were switched to monotherapy with clopidogrel (n=534) or aspirin (n=1,285) after uneventful 12-month DAPT were analyzed. The primary endpoint was net adverse clinical events (NACE), defined as a composite of death from any cause, MI, repeat percutaneous coronary intervention (PCI), stent thrombosis, ischemic stroke, or major bleeding during the period from 12 to 24 months.RESULTS: After adjustment using inverse probability of treatment weighting, patients who received clopidogrel, compared with those treated with aspirin, had a similar incidence of NACE (0.7% and 0.7%; hazard ratio, 1.06; 95% confidence interval, 0.31–3.60; p=0.923). The 2 groups had similar rates of death from any cause (0.1% in each group, p=0.789), MI (0.3% and 0.1%, respectively; p=0.226), repeat PCI (0.1% and 0.3%, respectively; p=0.548), stent thrombosis (0.1% and 0%, respectively; p=0.121), major bleeding (0.2% in each group, p=0.974), and major adverse cardiovascular and cerebrovascular events (0.5% in each group, p=0.924).CONCLUSIONS: Monotherapy with clopidogrel, compared to aspirin, after DAPT showed similar clinical outcomes in patients with acute MI treated with DES.
Aspirin ; Drug-Eluting Stents ; Hemorrhage ; Humans ; Incidence ; Korea ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Platelet Aggregation Inhibitors ; Stents ; Stroke ; Thrombosis

PURPOSE: Head and neck squamous cell carcinoma (HNSCC) is a deadly disease in which precision medicine needs to be incorporated. We aimed to implement next-generation sequencing (NGS) in determining actionable targets to guide appropriate molecular targeted therapy in HNSCC patients. MATERIALS AND METHODS: Ninety-three tumors and matched blood samples underwent targeted sequencing of 244 genes using the Illumina HiSeq 2500 platform with an average depth of coverage of greater than 1,000×. Clinicopathological data from patients were obtained from 17 centers in Korea, and were analyzed in correlation with NGS data. RESULTS: Ninety-two of the 93 tumors were amenable to data analysis. TP53 was the most common mutation, occurring in 47 (51%) patients, followed by CDKN2A (n=23, 25%), CCND1 (n=22, 24%), and PIK3CA (n=19, 21%). The total mutational burden was similar between human papillomavirus (HPV)–negative vs. positive tumors, although TP53, CDKN2A and CCND1 gene alterations occurred more frequently in HPV-negative tumors. HPV-positive tumors were significantly associated with immune signature-related genes compared to HPV-negative tumors. Mutations of NOTCH1 (p=0.027), CDKN2A (p < 0.001), and TP53 (p=0.038) were significantly associated with poorer overall survival. FAT1 mutations were highly enriched in cisplatin responders, and potentially targetable alterations such as PIK3CA E545K and CDKN2A R58X were noted in 14 patients (15%). CONCLUSION: We found several targetable genetic alterations, and our findings suggest that implementation of precision medicine in HNSCC is feasible. The predictive value of each targetable alteration should be assessed in a future umbrella trial using matched molecular targeted agents.
Biomarkers ; Carcinoma, Squamous Cell* ; Cisplatin ; Epithelial Cells* ; Head* ; Humans ; Korea ; Molecular Targeted Therapy ; Neck* ; Precision Medicine ; Statistics as Topic

BACKGROUND/AIMS: There are only a few reports on the direct costs of severe cutaneous adverse reactions (SCARs), including drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN), despite the tremendous negative impact these reactions can have on patients. We estimated the direct costs of treating SCARs. METHODS: Patients admitted to a tertiary teaching hospital for the treatment of SCARs from January 1, 2005 to December 31, 2010 were included. Patients who had experienced SCARs during their admission for other medical conditions were excluded. The direct costs of hospitalization and outpatient department visits were collected. Inpatient and outpatient care costs were calculated, and factors affecting inpatient care costs were analyzed. RESULTS: The total healthcare cost for the management of 73 SCAR patients (36 with DRESS, 21 with SJS, and 16 with TEN) was 752,067 US dollars (USD). Most of the costs were spent on inpatient care (703,832 USD). The median inpatient care cost per person was 3,720 (range, 1,133 to 107,490) USD for DRESS, 4,457 (range, 1,224 to 21,428) USD for SJS, and 8,061 (range, 1,127 to 52,220) USD for TEN. Longer hospitalization significantly increased the inpatient care costs of the patients with DRESS (by 428 USD [range, 395 to 461] per day). Longer hospitalization and death significantly increased the inpatient care costs of the patients with SJS/TEN (179 USD [range, 148 to 210] per day and an additional 14,425 USD [range, 9,513 to 19,337] for the deceased). CONCLUSIONS: The management of SCARs required considerable direct medical costs. SCARs are not only a health problem but also a significant financial burden for the affected individuals.
Ambulatory Care ; Cicatrix ; Drug Hypersensitivity Syndrome ; Health Care Costs ; Hospitalization ; Hospitals, Teaching ; Humans ; Inpatients ; Korea* ; Outpatients ; Stevens-Johnson Syndrome ; Tertiary Care Centers*

Oxidative stress is considered a major contributor in the pathogenesis of diabetic neuropathy and in diabetes complications, such as nephropathy and cardiovascular diseases. Diabetic neuropathy, which is the most frequent complications of diabetes, affect sensory, motor, and autonomic nerves. This study aimed to investigate whether 7,8-dihydroxyflavone (7,8-DHF) protects SH-SY5Y neuronal cells against high glucose-induced toxicity. In the current study, we found that diabetic patients exhibited higher lipid peroxidation caused by oxidative stress than healthy subjects. 7,8-DHF exhibits superoxide anion and hydroxyl radical scavenging activities. High glucose-induced toxicity severely damaged SH-SY5Y neuronal cells, causing mitochondrial depolarization; however, 7,8-DHF recovered mitochondrial polarization. Furthermore, 7,8-DHF effectively modulated the expression of pro-apoptotic protein (Bax) and anti-apoptotic protein (Bcl-2) under high glucose, thus inhibiting the activation of caspase signaling pathways. These results indicate that 7,8-DHF has antioxidant effects and protects cells from apoptotic cell death induced by high glucose. Thus, 7,8-DHF may be developed into a promising candidate for the treatment of diabetic neuropathy.
Antioxidants ; Autonomic Pathways ; Cardiovascular Diseases ; Cell Death ; Diabetes Complications ; Diabetic Neuropathies ; Glucose ; Healthy Volunteers ; Humans ; Hydroxyl Radical ; Lipid Peroxidation ; Neurons* ; Oxidative Stress* ; Superoxides

The prevalence of heart failure (HF) is on the rise due to the aging of society. Furthermore, the continuous progress and widespread adoption of screening and diagnostic strategies have led to an increase in the detection rate of HF, effectively increasing the number of patients requiring monitoring and treatment. Because HF is associated with substantial rates of mortality and morbidity, as well as high socioeconomic burden, there is an increasing need for developing specific guidelines for HF management. The Korean guidelines for the diagnosis and management of chronic heart failure (CHF) were introduced in March 2016. However, CHF and acute heart failure (AHF) represent distinct disease entities. Here, we introduce the Korean guidelines for the management of AHF with reduced or preserved ejection fraction. Part III of this guideline covers management strategies optimized according to the etiology of AHF and the presence of co-morbidities.
Aging ; Comorbidity ; Diagnosis ; Heart Failure ; Heart ; Humans ; Mass Screening ; Mortality ; Prevalence

BACKGROUND AND OBJECTIVES: Beta-blockers are indicated in patients with heart failure (HF) with reduced ejection fraction. However, their efficacy in patients with HF with preserved ejection fraction (HFpEF) is uncertain. We investigated the hypothesis that beta-blockers are associated with reduced adverse events in patients with HFpEF. METHODS: The Korea Acute Heart Failure (KorAHF) is a prospective observational multicentre cohort study. The 5,625 patients hospitalized for acute HF syndrome in 10 tertiary university hospitals across the country have been consecutively enrolled between March 2011 and February 2014. Of these patients, 2,152 patients with HFpEF (ejection fraction ≥40%) were investigated. The primary outcome was all-cause mortality according to beta-blocker use. RESULTS: During a median follow-up duration of 807 days, 702 patients died. In Cox proportional hazards model beta-blocker use was associated with a 14% reduced all-cause death (hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.75–0.98), but not with reduce rehospitalization (HR, 1.03; 95% CI, 0.85–1.27). In the propensity-score matched population, beta-blockers were also associated with reduced all-cause death (HR, 0.80; 95% CI, 0.69–0.94) but not with reduced rehospitalization (HR, 1.08; 95% CI, 0.87–1.33). CONCLUSIONS: In Korean patients with HFpEF, use of beta-blockers is associated with reduced all-cause death but not with reduced rehospitalization.
Cohort Studies ; Diastole ; Follow-Up Studies ; Heart Failure ; Heart ; Hospitals, University ; Humans ; Korea ; Mortality ; Proportional Hazards Models ; Prospective Studies

BACKGROUND AND OBJECTIVES: Coronary artery calcium (CAC) scoring in the asymptomatic population can improve cardiovascular risk prediction. We aimed to assess CAC progression and the impact of coronary risk factors on the CAC progression rate in asymptomatic Korean individuals with a baseline CAC score of zero. METHODS: The study population was derived from the Korea Initiatives on Coronary Artery Calcification (KOICA) registry: a retrospective, single ethnicity, multicenter registry of asymptomatic individuals who underwent CAC scoring as a part of a health checkup. Individuals with at least two CAC scores and an initial score of zero were included. CAC progression was defined as [√CAC score (follow-up) − √CAC score (baseline)] ≥2.5. The 10-year atherosclerotic cardiovascular disease (ASCVD) risk was calculated. RESULTS: Among 6,268 participants (mean age, 48.0±7.1 years; male, 80.5%), 719 (11.5%) experienced CAC progression during follow-up (median, 109 months; interquartile range, 78–208 months). The CAC progression rate was 0.3%, 1.9%, 4.3%, 8.6%, and 16.7% in years 1–5, respectively. The chance of CAC progression at 5 years was 13.1%, 22.0%, and 27.9% for individuals with a 10-year ASCVD risk of <5%, ≥5% but <7.5%, and ≥7.5%, respectively. A multivariable analysis revealed age, male sex, waist circumference, diabetes, and low-density lipoprotein cholesterol level as independently associated with annualized CAC progression (p<0.001, p=0.017, p=0.025, p=0.032, and p=0.003, respectively). CONCLUSIONS: The probability of CAC progression is very low in Korean individuals with a CAC score of zero. However, the risk of CAC progression increases nonlinearly over time, and increases as the 10-year ASCVD risk increases.
Calcium ; Cardiovascular Diseases ; Cholesterol ; Coronary Vessels ; Follow-Up Studies ; Humans ; Korea ; Lipoproteins ; Male ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Waist Circumference

BACKGROUND AND OBJECTIVES: Although current guidelines recommend early initiation of statin in patients with acute myocardial infarction (AMI), there is no consensus for optimal timing of statin initiation. METHODS: A total of 3,921 statin-naïve patients undergoing percutaneous coronary intervention were analyzed, and divided into 3 groups according to statin initiation time: group 1 (statin initiation <24 hours after admission), group 2 (24–48 hours) and group 3 (≥48 hours). We also made 3 stratified models to reduce bias: model 1 (<24 hours vs. ≥24 hours), model 2 (<48 hours vs. ≥48 hours) and model 3 (<24 hours vs. 24–48 hours). The endpoint was major adverse cardiac events (MACE; composite of cardiac death, myocardial infarction and target-vessel revascularization) during median 3.8 years. RESULTS: During follow-up, incidence of MACE was lower in early statin group in both model 1 (14.3% vs. 18.4%, hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.66–0.91; p=0.002) and model 2 (14.6% vs. 19.7%, HR, 0.81; 95% CI, 0.67–0.97; p=0.022). After propensity-score matching, results remained unaltered. Statin initiation <24 hours reduced MACE compared to statin initiation ≥24 hours in model 1. Statin initiation <48 hours also reduced MACE compared to statin initiation later in model 2. However, there was no difference in incidence of MACE between statin initiation <24 hours and 24–48 hours) in model 3. CONCLUSIONS: Early statin therapy within 48 hours after admission in statin-naïve patients with AMI reduced long-term clinical outcomes compared with statin initiation later. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02385682
Bias (Epidemiology) ; Consensus ; Death ; Follow-Up Studies ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Incidence ; Myocardial Infarction ; Percutaneous Coronary Intervention