Sungha Park

Yonsei University Hospital, Sŏul, Seoul, South Korea

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Publications (130)353.16 Total impact

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    ABSTRACT: Insulin resistance has an important role in the pathogenesis of hypertension. We hypothesized that impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) which represents insulin resistance would predict the development of hypertension.
    American journal of hypertension. 09/2014;
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    ABSTRACT: A hypertensive response to exercise (HRE) is known to be associated with higher risk of heart failure and future cardiovascular events in patients with hypertension. Left atrial volume index (LAVI) is associated with the diastolic dysfunction, indicating exercise intolerance. Therefore, we investigated whether LAVI is relevant to HRE during cardiopulmonary exercise test (CPET). We studied 118 consecutive hypertensive patients (61 men, 57±11 years) and 45 normotensive control subjects (16 men, 54±8 years). Clinical characteristics, CPET, echocardiographic and laboratory findings were assessed at the time of enrollment. HRE was defined as maximum systolic blood pressure (SBP)⩾210 mm Hg in men and ⩾190 mm Hg in women. HRE was more prevalent in hypertensive patients compared with normotensive control subjects (50.8% vs. 20.0%, P<0.001). Age and baseline SBP were shown to be associated with HRE in normotensive control subjects, as were baseline SBP and LAVI in hypertensive group. In multivariate analysis, LAVI was found to be an independent predictor of HRE in hypertensive patients (P=0.020) but not in normotensive control subjects (P=0.936) when controlled for age, sex, body mass index and peak oxygen consumption. Higher LAVI, reflecting the duration and severity of increased left atrial pressure is independently associated with HRE in hypertensive patients, but not in normotensive control subjects.Hypertension Research advance online publication, 25 September 2014; doi:10.1038/hr.2014.146.
    Hypertension research : official journal of the Japanese Society of Hypertension. 09/2014;
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    ABSTRACT: Obstructive sleep apnea (OSA) is considered an independent risk factor for hypertension. However, it is still not clear which clinical factors are related with the presence of hypertension in OSA patients. We aimed to find different physical features and compare the sleep study results which are associated with the occurrence of hypertension in OSA patients.
    Yonsei medical journal. 09/2014; 55(5):1310-7.
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    ABSTRACT: Background:High-dose statin loading is known to reduce periprocedural myocardial infarction and contrast-induced acute kidney injury in patients undergoing percutaneous coronary intervention. However, the clinical role of high-dose statin loading in patients with acute heart failure (AHF) remains unknown.Methods and Results:In a prospective, single-center, randomized, controlled, open-label pilot study, patients hospitalized with AHF were randomly assigned to receive oral high-dose atorvastatin loading (80 mg for 3 days, followed by 10 mg/day until discharge) or no statin therapy, on top of optimal HF treatment. The primary outcome measures were changes to the level of biomarkers related to inflammation and renal injury from admission to hospital day 4. No significant changes in the levels of NT-proBNP (-2,627±4,956 vs. -2,981±6,951 pg/ml, P=0.845), hsCRP (-6.1±16.4 vs. -2.1±16.2 mg/L, P=0.105), cystatin C (0.002±0.185 vs. 0.009±0.216 mg/L, P=0.904), ACR (-886.3±1,984.9 vs. -165.6±825.2 mg/day, P=0.124) were observed in either group. In-hospital mortality (4.3% vs. 3.8%, P>0.999) and all-cause mortality at 90 days (4.3% vs. 3.8%, P>0.999) were not significantly different between groups.Conclusions:This pilot study showed that oral high-dose atorvastatin loading may be used safely in patients with AHF, but is not effective in reducing the levels of circulating biomarkers related to inflammation and renal injury during hospitalization.
    Circulation journal : official journal of the Japanese Circulation Society. 08/2014;
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    ABSTRACT: Although T cells are known to be involved in the pathogenesis of coronary artery disease, it is unclear which subpopulation of T cells contributes to pathogenesis in acute myocardial infarction (MI). We studied the immunological characteristics and clinical impact of CD8(+)CD57(+) T cells in acute MI patients. The frequency of CD57(+) cells among CD8(+) T cells was examined in peripheral blood sampled the morning after acute MI events. Interestingly, the frequency of CD57(+) cells in the CD8(+) T-cell population correlated with cardiovascular mortality 6 months after acute MI. The immunological characteristics of CD8(+)CD57(+) T cells were elucidated by surface immunophenotyping, intracellular cytokine staining and flow cytometry. Immunophenotyping revealed that the CD8(+)CD57(+) T cells were activated, senescent T cells with pro-inflammatory and tissue homing properties. Because a high frequency of CD8(+)CD57(+) T cells is associated with short-term cardiovascular mortality in acute MI patients, this specific subset of CD8(+) T cells might contribute to acute coronary events via their pro-inflammatory and high cytotoxic capacities. Identification of a pathogenic CD8(+) T-cell subset expressing CD57 may offer opportunities for the evaluation and management of acute MI.Cellular & Molecular Immunology advance online publication, 25 August 2014; doi:10.1038/cmi.2014.74.
    Cellular & molecular immunology. 08/2014;
  • International journal of cardiology. 08/2014;
  • Journal of cardiac failure. 08/2014; 20(8S):S59-S60.
  • Journal of cardiac failure. 08/2014; 20(8S):S107.
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    ABSTRACT: Background:Because fatal arrhythmia is an important cause of death in patients with myocarditis, we investigated the proarrhythmic mechanisms of experimental autoimmune myocarditis.Methods and Results:Myocarditis was induced by injection of 2 mg porcine cardiac myosin into the footpads of adult Lewis rats on days 1 and 8 (Myo, n=15) and the results compared with Control rats (Control, n=15). In an additional 15 rats, 6 mg/kg prednisolone was injected into the gluteus muscle before the injection of porcine cardiac myosin on days 1 and 8 (MyoS, n=15). Hearts with myocarditis had longer action potential duration (APD), slower conduction velocity (CV; P<0.01 vs. Control), higher CV heterogeneity, greater fibrosis, higher levels of immunoblotting of high-mobility group protein B1, interleukin 6 and tumor necrosis factor-α proteins. Steroid treatment partially reversed the translations for myocarditis, CV heterogeneity, reduced APD at 90% recovery to baseline, increased CV (P<0.01), and reversed fibrosis (P<0.05). Programmed stimulation triggered sustained ventricular tachycardia in Myo rats (n=4/5), but not in controls (n=0/5) or Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor (KN93) treated Myo rats (n=0/5, P=0.01). CaMKII autophosphorylation at Thr287 (201%), and RyR2 phosphorylation at Ser2808 (protein kinase A/CaMKII site, 126%) and Ser2814 (CaMKII site, 21%) were increased in rats with myocarditis and reversed by steroid.Conclusions:The myocarditis group had an increased incidence of arrhythmia caused by increased phosphorylation of Ca(2+)handling proteins. These changes were partially reversed by an antiinflammatory treatment and CaMKII inhibition.
    Circulation journal : official journal of the Japanese Circulation Society. 07/2014;
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    ABSTRACT: The aim of this study was to investigate whether nocturnal blood pressure (BP), established on the basis of a single 24-h BP monitoring, is a stronger predictor of left ventricular hypertrophy (LVH) compared with nondipping status in the essential hypertensive patients.
    Journal of hypertension. 07/2014;
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    ABSTRACT: Aims/IntroductionWe aimed to examine the effect of an angiotensin II receptor blocker (ARB), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist, and their combination on myocardial fibrosis and function in type 2 diabetic rats.Materials and Methods Five male Long-Evans Tokushima Otsuka (LETO) rats and 20 male Otsuka Long-Evans Tokushima Fatty (OLETF) rats were used. OLETF rats were assigned to four groups (n = 5 per group) at 28 weeks-of-age: untreated, losartan-treated, rosiglitazone-treated and combination-treated. The ARB, losartan, was administered at a dose of 5 mg/kg/day, and the PPAR-gamma agonist, rosiglitazone, was administered at a dose of 3 mg/kg/day by oral gavage for 12 weeks. Urine and blood samples were collected, and two-dimensional echocardiograms and strain rate imaging were obtained at 28 and 40 weeks. Cytokines were evaluated by reverse transcriptase polymerase chain reaction, and histological analysis was carried out at 40 weeks.ResultsAt 40 weeks, the global radial strains of the losartan-treated (55.7 ± 4.5%, P = 0.021) and combination-treated groups (59.3 ± 6.7%, P = 0.001) were significantly higher compared with the untreated OLETFs (44.3 ± 10.5%). No difference was observed when compared with LETO rats. Although the rosiglitazone-treated group showed a better metabolic profile than the untreated OLETF group, there was no difference in the global radial strain (49.8 ± 6.0 vs 44.3 ± 10.5, P = 0.402). The expression of pro-inflammatory cytokines, and collagen type I and III were consistently attenuated in the losartan-treated and combination-treated OLETF groups, but not in the rosiglitazone-treated group.ConclusionsA combination of rosiglitazone and losartan attenuates myocardial fibrosis and dysfunction in type 2 diabetic rats.
    Journal of Diabetes Investigation. 07/2014; 5(4).
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    Chan Joo Lee, Sungha Park
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    ABSTRACT: Primary prevention and early detection of cardiovascular disease is important, as it is the leading cause of death throughout world. Risk stratification algorithms, such as Framingham Risk Score and European Systematic Coronary Risk Evaluation, that utilize a combination of various traditional risk factors have been developed to improve primary prevention. However, the accuracy of these algorithms for screening high risk patients is moderate at best. Accordingly, the use of biomarkers or imaging studies may improve risk stratification. Carotid ultrasound, which measures both carotid intima-media thichkness (cIMT) and carotid plaque, is useful in detecting the degree of subclinical carotid atherosclerosis, and has the advantage of being noninvasive and safe. Several large epidemiologic studies have indicated that cIMT and carotid plaque are closely related with other cardiovascular risk factors and may be useful for risk reclassification in subjects deemed to be at intermediate risk by traditional risk scores. Moreover, recent clinical guidelines for management of hypertension or dyslipidemia highlight the usefulness of cIMT in high risk patients. In this article, we review evidence for the usefulness of measurement of cIMT and carotid plaque for cardiovascular risk stratification.
    Yonsei medical journal 05/2014; 55(3):551-7. · 0.77 Impact Factor
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    ABSTRACT: Peak oxygen uptake (peak VO₂) and ventilatory inefficiency (VE/VCO₂ slope) have proven to be strong prognostic markers in patients with chronic heart failure (CHF). Recently increased red cell distribution width (RDW) has emerged as an additional predictor of poor outcome in CHF. We sought to evaluate the relationship between RDW and cardiopulmonary exercise test (CPET) parameters in CHF patients and healthy controls. 85 ambulatory CHF patients (68 men, 54±10 years) and 107 healthy controls, who underwent a symptom-limited CPET on a treadmill according to the modified Bruce ramp protocol, were enrolled. CHF patients and healthy controls were divided into RDW tertile groups and laboratory, echocardiographic, and CPET results were analyzed. For patients with CHF, compared with patients in the lowest RDW tertile, those in the highest tertile had lower peak VO₂ (22 mL/kg/min vs. 28 mL/kg/min, p<0.001) and higher VE/VCO₂ slope (31 vs. 25, p=0.004). Multivariate regression analysis revealed RDW to be an independent predictor for peak VO₂ (β=-0.247, p=0.035) and VE/VCO₂ slope (β=0.366, p=0.004). The optimal cutoff value of RDW for predicting peak VO₂ ≤20 mL/kg/min and VE/VCO₂ slope≥34 was 13.6% (sensitivity 53%, specificity 89%) and 13.4% (sensitivity 75%, specificity 82%), respectively. In contrast, for healthy controls, RDW was not related to both peak VO₂ and VE/VCO₂ slope. Higher RDW is independently related to peak VO₂ and VE/VCO₂ slope only in patients with CHF. RDW assessment, an inexpensive and simple method, might help predict functional capacity and ventilatory efficiency in these patients.
    Yonsei medical journal 05/2014; 55(3):635-43. · 0.77 Impact Factor
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    ABSTRACT: Background: The Receptor for Advanced Glycation End Products (RAGE) is a pattern recognition receptor for endogenous ligands, and is associated with various inflammatory diseases. However, the role of RAGE activation in myocarditis has yet to be examined. The potential role of RAGE in the development of experimental autoimmune myocarditis (EAM) and the effect of RAGE blocking in attenuating the inflammation in the EAM was investigated. Methods and Results: EAM was evoked in Lewis rats by immunization with porcine cardiac myosin. Soluble RAGE (sRAGE) was injected to block RAGE activation. Echocardiogram, histological, and immunohistochemical examinations were conducted on days 21 and 42. In rats with EAM, RAGE expression in cardiac tissue was prominent on day 21. Rats administered sRAGE during the early antigen-priming phase showed marked attenuation in acute and chronic inflammation compared with untreated rats. RAGE expression was significantly reduced in rats treated in the early phase. However, sRAGE administration, after the initial antigen-priming phase, failed to ameliorate EAM development. Conclusions: RAGE expression was significantly increased in the heart during EAM. Blocking RAGE activation with sRAGE during the early antigen-priming phase reduced acute and chronic inflammation and improved cardiac function. In contrast, blocking RAGE after the early phase did not attenuate EAM development. These results imply that RAGE is involved in regulating innate immune responses during the early phase of myocarditis development.
    Circulation Journal 03/2014; · 3.58 Impact Factor
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    Soyeon Lim, Sungha Park
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    ABSTRACT: Atherosclerosis is a pathologic process occurring within the artery, in which many cell types, including T cell, macrophages, endothelial cells, and smooth muscle cells, interact, and cause chronic inflammation, in response to various inner- or outer-cellular stimuli. Atherosclerosis is characterized by a complex interaction of inflammation, lipid deposition, vascular smooth muscle cell proliferation, endothelial dysfunction, and extracellular matrix remodeling, which will result in the formation of an intimal plaque. Although the regulation and function of vascular smooth muscle cells are important in the progression of atherosclerosis, the roles of smooth muscle cells in regulating vascular inflammation are rarely focused upon, compared to those of endothelial cells or inflammatory cells. Therefore, in this review, we will discuss here how smooth muscle cells contribute or regulate the inflammatory reaction in the progression of atherosclerosis, especially in the context of the activation of various membrane receptors, and how they may regulate vascular inflammation.
    BMB reports 01/2014; · 1.63 Impact Factor
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    ABSTRACT: C-reactive protein (CRP) is one of the most important biomarkers for arteriosclerosis and cardiovascular disease. Recent studies have shown that CRP affects cell cycle and inflammatory process in cardiac myocytes. Survivin is also involved in cardiac myocytes replication and apoptosis. Reduction of survivin expression is associated with less favorable cardiac remodeling in animal models. However, the effect of CRP on survivin expression and its cellular mechanism has not yet been studied. We demonstrated that treatment of CRP resulted in a significant decrease of survivin protein expression in a concentration-dependent manner in cardiac myocytes. The upstream signaling proteins of survivin, such as Akt, mTOR and p70S6K, were also downregulated by CRP treatment. In addition, CRP increased the protein and mRNA levels of PTEN. The siRNA transfection or specific inhibitor treatment for PTEN restored the CRP-induced downregulation of Akt/mTOR/p70S6K pathway and survivin protein expression. Moreover, pretreatment with a specific p53 inhibitor decreased the CRP-induced PTEN expression. ERK-specific inhibitor also blocked the p53 phosphorylation and PTEN expression induced by CRP. Our study provides a novel insight into CRP-induced downregulation of survivin protein expression in cardiac myocytes through mechanisms that involved in downregulation of Akt/mTOR/p70S6K pathway by expression of PTEN.
    PLoS ONE 01/2014; 9(5):e98113. · 3.53 Impact Factor
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    ABSTRACT: Background The long-term prognosis of biopsy-proven myocarditis is not well known. We hypothesized that a detailed pathological examination of an endomyocardial biopsy (EMB) would reveal prognostic information in patients with acute myocarditis. Methods Fifty-four patients were diagnosed with acute myocarditis based on an EMB. Pathological diagnosis was categorized into lymphocytic dominant (29.6%), eosinophilic dominant (22.2%), and borderline myocarditis (48.1%). Masson’s trichrome staining and further immunohistochemical staining for CD3, CD20, CD68, HLA-DR, TLR4, TLR8, enteroviral VP1, and caspase-3 expression were performed. The clinical outcomes were defined as all-cause and cardiovascular (CV) death. Results During the median 10.4 years of follow up (9.7 ± 5.7 years), the overall all-cause mortality was 20.4% and the CV mortality was 14.8% in patients with acute myocarditis. Lymphocytic dominant myocarditis patients showed a poor clinical outcome when compared with eosinophilic dominant myocarditis patients for both all-cause (37.5% vs. 0%, p=0.015) and CV (31.2% vs. 0%, p=0.029) mortality. Among borderline myocarditis patients, the presence of fibrosis was linked with poor clinical outcomes in both all-cause (75.0% vs. 21.4%, p=0.045) and CV (100.0% vs. 25.0%, p=0.034) mortality. No significant associations between clinical outcome and all other immunohistochemical staining targets were observed. Conclusions Detailed pathological evaluation on an EMB provides prognostic information in patients with acute myocarditis. EMB evaluation should be considered in patients with suspected myocarditis. Summary We categorized biopsy proven acute myocarditis patents into lymphocytic, eosinophilic and borderline myocarditis, and further evaluated fibrosis by Masson's trichrome and other immunohistochemical staining. Lymphocyte dominant myocarditis have poor prognosis than eosinophilic myocarditis. Furthermore, the presence of fibrosis in borderline myocarditis was linked with poor outcome while other immunohistochemical analysis showed no significant association with clinical outcome.
    Cardiovascular pathology: the official journal of the Society for Cardiovascular Pathology 01/2014; · 1.63 Impact Factor
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    ABSTRACT: In patients with acute decompensated heart failure (ADHF), the prognostic value of new-onset anemia with regard to renal function has not been investigated. Consecutive 299 ADHF patients (162 men, 62±14 years) were enrolled. Cardiovascular (CV) events composite of CV mortality and rehospitalization occurred in 113 patients (37.8%) during 2 years of follow-up. Baseline anemia was prevalent (n=124, 41.5%) and 43 patients (14.4%) had new-onset anemia at 1 month after discharge. Baseline anemia was strongly associated with CV events risk in overall [hazard ratio (HR): 1.79, 95% CI: 1.17-2.74, p=0.006] and those with preserved renal function [estimated glomerular filtration rate (eGFR)≥45mL/min/1.73m(2)] (HR: 1.81, 95% CI: 1.05-3.12, p=0.031). In patients with severe renal dysfunction (eGFR<45mL/min/1.73m(2)), new-onset anemia independently predicted CV events (HR: 2.72, 95% CI: 1.09-6.76, p=0.031) whereas baseline anemia did not (HR: 1.28, 95% CI: 0.61-2.65, p=0.505). New-onset anemia was significantly associated with hemodilution, which may reflect inadequate decongestion in ADHF patients. Baseline anemia was an independent prognostic factor in overall ADHF patients and those with preserved renal function. New-onset anemia as a surrogate for hemodilution better predicted CV events than baseline anemia in ADHF patients with severe renal dysfunction.
    Journal of Cardiology 12/2013; · 2.30 Impact Factor
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    ABSTRACT: This study was designed to evaluate retrospectively the efficacy of C-arm CT to confirm right adrenal vein catheterization during adrenal vein sampling (AVS) and to correlate adrenal venography findings with C-arm CT and/or biochemical results for right adrenal vein selection. Forty-two consecutive primary aldosteronism patients (M:F = 21:21; age: 29-70 years) underwent C-arm CT assisted sequential AVS. After catheterization of right adrenal vein, C-arm CT was performed to confirm catheter position. Catheter was repositioned when right adrenal gland was not opacified. Radiological images, medical records, and biochemical results were reviewed for technical/biochemical success rates and complications. Right adrenal venography findings of pinnate pattern, visualization of renal capsular vein, and retroperitoneal vein other than renal capsular vein were correlated with C-arm CT and/or biochemical results for right adrenal vein selection. Both the technical and biochemical success of AVS was achieved in 40 patients (95.2 %). C-arm CT failed due to catheter instability in one, and adrenal/vena cava cortisol gradient was <3 in one patient. Catheter was repositioned in four patients (9.5 %) according to C-arm CT findings. Right adrenal venography finding of renal capsular vein significantly correlated with C-arm CT and/or biochemical results (100 %) for right adrenal vein selection (p = 0.011, χ (2) test), whereas pinnate pattern (p = 0.099) and other retroperitoneal veins (p = 0.347) did not. There was no procedure-related complication. C-arm CT increases confidence of right adrenal vein catheterization during AVS. Visualization of renal capsular vein on adrenal venography suggests right adrenal vein catheterization and C-arm CT may not be required.
    CardioVascular and Interventional Radiology 12/2013; · 2.09 Impact Factor
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    ABSTRACT: Targeting metabolic syndrome (MetS) in early chronic kidney disease (CKD) is essential to reduce cardiovascular complications. We compared the association of kidney function estimated by two glomerular filtration rate (GFR) equations with MetS in community population. We analyzed 12,700 participants from 2009 to 2010 the Korea National Health Survey data. GFR was estimated using the CKD Epidemiology Collaboration equation (GFRCKD-EPI) and the Modification of Diet in Renal Disease study equation (GFRMDRD). The prevalence of MetS increased from the highest GFR category (>105ml/min/1.73m(2)) to the lowest (<60ml/min/1.73m(2)) using both equations (GFRCKD-EPI, 14.1% to 62.3%; GFRMDRD, 18.4% to 62.9%). Participants reclassified to higher GFRCKD-EPI category (upward) from GFRMDRD had lower prevalence of MetS than those moved downward (Net reclassification improvement 13.7%, P<0.001). Compared with GFR ≥105ml/min/1.73m(2), mildly impaired GFRCKD-EPI (75-89ml/min/1.73m(2)) was independently associated with increased odds of MetS (OR 1.30, 95% CI 1.09-1.56, P=0.003) in multivariate analysis, whereas GFRMDRD was not (OR 1.08, 95% CI 0.92-1.27, P=0.344). Compared with GFRMDRD, GFRCKD-EPI showed better association with prevalence of MetS, particularly in normal to mildly impaired GFR range. GFRCKD-EPI may improve risk stratification of individuals with MetS according to kidney function in community-based population.
    Clinica chimica acta; international journal of clinical chemistry 12/2013; · 2.54 Impact Factor

Publication Stats

888 Citations
353.16 Total Impact Points

Institutions

  • 2003–2014
    • Yonsei University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea
  • 2013
    • Seoul National University Hospital
      • Department of Internal Medicine
      Seoul, Seoul, South Korea
  • 2007–2013
    • Yonsei University
      • Department of Food and Nutrition
      Sŏul, Seoul, South Korea
    • Kwandong University
      Gangneung, Gangwon, South Korea
    • CHA University
      • College of Medicine
      Seoul, Seoul, South Korea
  • 2011
    • National Health Insurance Corporation Ilsan Hospital
      Sŏul, Seoul, South Korea
  • 2009
    • Korea University
      • Department of Food and Nutrition
      Seoul, Seoul, South Korea
  • 2008
    • Chonnam National University
      Gwangju, Gwangju, South Korea
  • 2005–2006
    • Hallym University Medical Center
      • Department of Internal Medicine
      Seoul, Seoul, South Korea