Heung Up Kim

Seroprevalence of Helicobacter pylori in South Korea

Background:  Helicobacter pylori‐associated gastrointestinal diseases have been widely recognized. The aims of this study were to investigate the interval change of seropositivity of H. pylori between 1998 and 2005 in Korean adult population and to find the factors related to H. pylori infection.

Prevalence and risk factors of Helicobacter pylori infection in Korea: Nationwide multicenter study over 13 years

BackgroundThe aim of this study was to evaluate the time trend of seropositivity of Helicobacter pylori (H. pylori) over the period of 13 years in an asymptomatic Korean population, and investigate associated risk factors.MethodsThis cross-sectional nationwide multicentre study surveyed anti-H. pylori IgG antibodies in 19,272 health check-up subjects (aged [greater than and equal to]16 years) in 2011. Risk factors for H. pylori infection were investigated using logistic regression. Seropositivity in asymptomatic subjects without H. pylori eradication was compared between the years 1998 and 2005. Birth cohort effects were also evaluated.ResultsAfter exclusion of subjects with a history of H. pylori eradication therapy (n = 3,712, 19.3%) and gastric symptoms (n = 4,764, 24.7%), the seroprevalence of H. pylori infection was 54.4% in 10,796 subjects. This was significantly lower than the seroprevalence of 59.6% in 2005 and that of 66.9% in 1998, and this decrease of seropositivity of H. pylori became widespread across all ages and in most areas of the country. This decreasing trend could be explained by cohort analysis. All younger birth cohorts had a lower seroprevalence of H. pylori than older birth cohorts at the same age. Decreased seroprevalence within the same birth cohorts also accounted for this phenomenon. Clinical risk factors of H. pylori infection were higher cholesterol level ([greater than and equal to] 240 mg/dl) (OR = 1.33; 95% CI = 1.14-1.54), male gender, older age, low income, and residence in a rural area.ConclusionsA decreasing trend of H. pylori seroprevalence due to a birth cohort effect requires further studies on its related human host factors as well as socio-economic and hygienic factors. In addition, the relationship between H. pylori infection and high cholesterol level needs more investigation regarding underlying pathogenesis.

Hepatitis B virus genotypes in Korea: an endemic area of hepatitis B virus infection.

Objectives: It has been reported that distribution of hepatitis B virus (HBV) genotypes shows geographic difference and are associated with clinical outcomes of HBV infection, including response to antiviral therapy and progression of chronic liver diseases. In this study, we analyzed the distribution of HBV genotypes according to the various clinical outcomes of chronic HBV infection in Korea, which is one of the most endemic areas of HBV infection. Methods: A total of 200 patients with chronic HBV infection were enrolled. Clinical diagnoses of the 200 patients with chronic liver diseases were as follows: hepatitis B e antigen (HBeAg)-positive healthy carrier (defined as HBeAg+, anti-HBe–, HBV DNA+ by hybridization, normal transaminase; n = 40); inactive HBsAg carrier (n = 40); chronic hepatitis B (n = 40); liver cirrhosis (n = 40); hepatocellular carcinoma (n = 40). HBV genotypes were determined by nested polymerase chain reaction using genotype-specific primers. Results: All patients except 2 (inactive HBsAg carriers) were positive for nested PCR and they have genotype C regardless of clinical outcomes. Conclusions: HBV genotype was genotype C regardless of various clinical outcomes of chronic HBV infection in Korea. Considering that HBV genotypes have clinical relevance, distribution of HBV genotype in each area should be monitored when management for chronic HBV infection is planned.

Prevalence and Risk Factors of Atrophic Gastritis and Intestinal Metaplasia: A Nationwide Multicenter Prospective Study in Korea

Background/Aims Atrophic gastritis (AG) and intestinal metaplasia (IM) are premalignant gastric lesions. The aims of this study were to evaluate the prevalence of endoscopic AG and IM and to document the risk factors for these lesions. Methods In total, 4,023 subjects were enrolled at eight hospitals in Korea. AG and IM were diagnosed by endoscopy. Helicobacter pylori immunoglobulin G antibodies were measured. Results The prevalences of endoscopic AG and IM were 40.7% and 12.5%. In a multivariate analysis, the risk factors for AG were age groups of 40 to 59 years and >60 years, male sex, positive H. pylori serology, IM, and education below the college level (odds ratio [OR], 2.55, 5.00, 1.38, 1.41, 4.29, and 1.35, respectively). The risk factors for IM were age groups of 40 to 59 years and >60 years, male sex, positive H. pylori serology, AG, having relatives with gastric cancer, education below the college level and consumption of dairy products (OR, 3.16, 3.25, 1.88, 2.17, 3.68, 1.48, 1.47, and 1.40, respectively). Conclusions A nationwide survey regarding the prevalence of endoscopic AG and IM and their risk factors in Korea supports the hypothesis that endoscopic diagnosis of these premalignant lesions could be helpful to describe a group at high risk for gastric cancer.

Endoscopic resection for duodenal carcinoid tumors: A multicenter, retrospective study

Gastrointestinal carcinoid tumors < 10 mm in diameter and limited to the submucosal layer demonstrate a low frequency of lymph node and distant metastasis, and are suitable for endoscopic treatment. The aim of this study was to assess the efficacy, safety, and long‐term prognosis of endoscopic resections for the treatment of duodenal carcinoid tumors.

Sequential accumulation of the basal core promoter and the precore mutations in the progression of hepatitis B virus-related chronic liver disease.

Objectives: Despite the pathogenic role of the basal core promoter (BCP) and the precore mutations in chronic hepatitis B virus (HBV) infection, their role in the progression of liver disease is still controversial. We analyzed whether the accumulation of these mutations might enhance the progression of HBV-related chronic liver disease. Methods: Forty consecutive patients at each clinical status were analyzed. Clinical statuses were as follows: HBeAg-positive asymptomatic carrier (HBeAg+ ASC) (defined as HBeAg+, anti-HBe–, HBV-DNA+ by hybridization, normal ALT); inactive HBsAg carrier; chronic hepatitis B; liver cirrhosis. The genotype and the BCP/precore regions were determined by PCR using genotype specific primers and direct sequencing, respectively. Results: All patients except one were infected with genotype C. The A to T mutation at nucleotide 1762 and/or G to A mutation at nucleotide 1764 were found in 30% in HBeAg+ ASC, 65.7% in inactive HBsAg carrier, 95% in chronic hepatitis B, and 90% in liver cirrhosis (p < 0.001). The prevalence of the G to A mutation at nucleotide 1896 was 5% in HBeAg+ ASC, 22.5% in inactive HBsAg carrier, 32.5% in chronic hepatitis B, and 50% in liver cirrhosis, respectively (p < 0.001). The T to C/A mutation at nucleotide 1753 in the BCP and G to A mutation at nucleotide 1899 in the precore were more frequent in liver cirrhosis than in the other clinical statuses (p < 0.05). Conclusion: Sequential accumulation of mutations in the BCP/precore has an important role in the progression of HBV-related liver disease.

Eradication Rates of Helicobacter pylori in Korea Over the Past 10 years and Correlation of the Amount of Antibiotics Use: Nationwide Survey.

The efficacy of proton‐pump inhibitor–amoxicillin–clarithromycin therapy for H. pylori eradication has decreased over time.

Long-term follow up of endoscopic resection for type 3 gastric NET

AIM To clarify the short and long-term results and to prove the usefulness of endoscopic resection in type 3 gastric neuroendocrine tumors (NETs). METHODS Of the 119 type 3 gastric NETs diagnosed from January 1996 to September 2011, 50 patients treated with endoscopic resection were enrolled in this study. For endoscopic resection, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) was used. Therapeutic efficacy, complications, and follow-up results were evaluated retrospectively. RESULTS EMR was performed in 41 cases and ESD in 9 cases. Pathologically complete resection was performed in 40 cases (80.0%) and incomplete resection specimens were observed in 10 cases (7 vs 3 patients in the EMR vs ESD group, P = 0.249). Upon analysis of the incomplete resection group, lateral or vertical margin invasion was found in six cases (14.6%) in the EMR group and in one case in the ESD group (11.1%). Lymphovascular invasions were observed in two cases (22.2%) in the ESD group and in one case (2.4%) in the EMR group (P = 0.080). During the follow-up period (43.73; 13-60 mo), there was no evidence of tumor recurrence in either the pathologically complete resection group or the incomplete resection group. No recurrence was reported during follow-up. In addition, no mortality was reported in either the complete resection group or the incomplete resection group for the duration of the follow-up period. CONCLUSION Less than 2 cm sized confined submucosal layer type 3 gastric NET with no evidence of lymphovascular invasion, endoscopic treatment could be considered at initial treatment.

Comparison of the Clinical Characteristics of Patients with Small Bowel and Gastric Anisakiasis in Jeju Island

Background/Aims Anisakiasis is frequent in Jeju Island because of the peoples habit of ingesting raw fish. This study evaluated the clinical characteristics of patients with small bowel anisakiasis and compared them with those of patients with gastric anisakiasis. Methods We retrospectively reviewed the medical records of 109 patients diagnosed with anisakiasis between May 2003 and November 2011. Results Of the 109 patients diagnosed with anisakiasis, those with suspicious anisakiasis (n=38) or possible anisakiasis (n=12) were excluded. The age and gender distributions did not differ between patients with small bowel anisakiasis (n=30; age, 45±13 years) and those with gastric anisakiasis (n=29; age, 46±10 years). The mean duration of hospitalization was 5.4±4.3 days for patients with small bowel anisakiasis and 0.5±1.7 days for patients with gastric anisakiasis. Small bowel anisakiasis was accompanied by leukocytosis (76.7% vs 25.5%, p=0.003) and elevated C-reactive protein levels (3.4±3.2 mg/dL vs 0.5±0.3 mg/dL, p=0.009). Contrast-enhanced abdominopelvic computed tomography showed small bowel wall thickening with dilatation in 93.3% (28/30) of patients and a small amount of ascites in 80.0% (24/30) of patients with small bowel anisakiasis. Conclusions Compared with gastric anisakiasis patients, small bowel anisakiasis patients had a longer hospitalization time, higher inflammatory marker levels, and small bowel wall thickening with ascites.

The Prevalence of Erosive Esophagitis Is Not Significantly Increased in a Healthy Korean Population - Could It Be Explained?: A Multi-center Prospective Study.

Background/Aims Researches on the potential risk factors for the development of erosive esophagitis have been conducted extensively, however, the results are conflicting. The aim of this multicenter study was to identify the prevalence rate and risk factors of erosive esophagitis and their interactions with residency status. Methods A total of 4,023 eligible subjects at 8 tertiary health care centers were evaluated using questionnaires, laboratory tests and endoscopy. Univariate and multivariate analyses were conducted to identify independent risk factors for erosive esophagitis. Results The prevalence rate of reflux esophagitis was 8.8%. Los Angeles grade A was common type of erosive esophagitis. Residence in a large urban areas was negatively associated with the development of erosive esophagitis (OR, 0.60; 95% CI, 0.40-0.90). The high body mass index (≥ 25 kg/m2) was more frequent in residents of small and medium-sized cities than those in big cities (38.8% and 26.9%, respectively; P < 0.001). Seronegativity of Helicobacter pylori was associated with increased erosive esophagitis (OR, 1.91; 95% CI, 1.48-2.46). Triglyceride ≥ 150 mg/dL (OR, 1.65; 95% CI, 1.08-2.07), fasting glucose level ≥ 126 mg/dL (OR, 1.73; 95% CI, 1.06-2.81), and hiatal hernia (OR, 3.11; 95% CI, 1.87-5.16) were also associated with erosive esophagitis. Conclusions The prevalence rate of erosive esophagitis and its risk factors in this study were similar to the result of 8.0% of nationwide study in 2006. Residency and obesity are more important independent risk factors than H. pylori infection status for development of erosive esophagitis in Korea. These results suggest that the prevalence rate of erosive esophagitis in Korea might not increase as in the Western countries.