Jeong Yoon Yim

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.

Non-alcoholic fatty liver disease across the spectrum of hypothyroidism

BACKGROUND & AIMS The aim of this study was to characterize the relationship between the broad spectrum of hypothyroidism and NAFLD. METHODS A cross-sectional study with 4648 health check-up subjects (2324 cases with hypothyroidism vs. age- and sex-matched controls) was conducted. The subjects were categorized as having either subclinical [thyroid-stimulating hormone (TSH) ≥4.1 mIU/L and normal free thyroixine (T(4)) level (0.7-1.8 ng/dl)] or overt hypothyroidism [free T(4)<0.7 ng/dl]. NAFLD was diagnosed on the basis of typical ultrasonographic findings, and alcohol consumption of less than 20 g/day in the absence of other causes of liver disease. RESULTS The mean age of the subjects was 48.6±11.8 years and 62.4% were female. NAFLD was significantly associated with hypothyroidism (30.2% patients vs. 19.5% control, p<0.001). The prevalence of NAFLD and abnormal liver enzyme levels (ALT>33/25 IU/L) increased steadily with increasing grades of hypothyroidism (for NAFLD, subclinical: 29.9% and overt: 36.3%; for abnormal ALT, 20.1% and 25.9%, p<0.001, respectively). Multivariate regression analysis showed that NAFLD was statistically significantly associated with hypothyroidism (odds ratio (OR) 1.38, 95% confidence interval (CI), 1.17-1.62) and the grade of hypothyroidism in a dose-dependent manner (OR 1.36, 95% CI, 1.16-1.61 in subclinical hypothyroidism and OR 1.71, 95% CI, 1.10-2.66 in overt hypothyroidism). CONCLUSIONS Subclinical hypothyroidism, even in the range of upper normal TSH levels, was found to be related to NAFLD in a dose-dependent manner. Hypothyroidism is closely associated with NAFLD independently of known metabolic risk factors, confirming a relevant clinical relationship between these two diseases.

Sagittal abdominal diameter is a strong anthropometric measure of visceral adipose tissue in the Asian general population.

OBJECTIVE Finding the anthropometric measure of visceral obesity is essential to clinical practice, because it predicts cardiovascular and metabolic risks. Sagittal abdominal diameter (SAD) has been proposed as an estimate of visceral adipose tissue (VAT). The aim of the present study was to evaluate the usefulness of SAD in predicting visceral obesity by comparing SAD to other anthropometric measures. RESEARCH DESIGN AND METHODS Estimation of subcutaneous and visceral adipose tissue and measurement of SAD and transverse abdominal diameter using computed tomography at the umbilical level were obtained in 5,257 men and women who were enrolled in a health checkup program in Korea. To compare SAD to other anthropometric measures, linear regression analyses were used to determine correlations between anthropometrics and visceral obesity. RESULTS SAD showed a stronger correlation to VAT than waist circumference, BMI, and transverse abdominal diameter in the both sexes (men: r = 0.804, women: r = 0.724). Waist circumference showed generally stronger associations to subcutaneous adipose tissue (SAT) than to VAT (men: r = 0.789 vs. 0.705, women: r = 0.820 vs. 0.636). Even after subdividing according to age or BMI in both sexes and analyzing multiple regressions, SAD showed the strongest correlation to VAT. CONCLUSIONS SAD showed the strongest correlation to VAT irrespective of age, sex, and the degree of obesity compared with other anthropometric measures, whereas waist circumference may have a stronger correlation to SAT than to VAT. The clinical use of SAD has advantages over other anthropometric measures in predicting VAT.

Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, 13C-urea breath test, and serology

Background and Aims:  This study aimed to evaluate the efficacy of a new polyclonal enzyme immunoassay for the detection of Helicobacter pylori (H. pylori) antigen in stool by determination of the optimal cut‐off value in the screening population.

Helicobacter pylori Serology Inversely Correlated With the Risk and Severity of Reflux Esophagitis in Helicobacter pylori Endemic Area: A Matched Case-Control Study of 5,616 Health Check-Up Koreans

Background/Aims The role of Helicobacter pylori in gastroesophageal reflux disease remains still controversial and the effect of the organism on severity of reflux esophagitis have been rarely issued. The aim of this study was to investigate the relationship between H. pylori infection and reflux esophagitis, and especially the severity of reflux esophagitis. Methods We performed a cross-sectional case-control study of 5,616 subjects undergoing both upper endoscopy and H. pylori serology during health Check-up (2,808 cases vs age- and sex-matched controls). Smoking, alcohol, body mass index and waist circum - ference were added to a multiple regression model. Results Prevalence of H. pylori infection was lower in cases with reflux esophagitis than in controls (38.4% vs 58.2%, P < 0.001) and negative associations with H. pylori infection continued across the grade of esophagitis (46.7% in Los Angeles classification M [LA-M], 34.3% in LA-A or LA-B and 22.4% in LA-C or LA-D, P < 0.001). Positive serology for H. pylori independently reduced the risk of reflux esophagitis (adjusted OR, 0.44; 95% CI, 0.39-0.49). Notably, the negative associations continued across the grade of esophagitis with adjusted ORs of 0.63 in LA-M, 0.36 in LA-A or LA-B and 0.20 in LA-C or LA-D (P < 0.001). Conclusions In a age-sex matched Korean, H. pylori seropositivity was independently and inversely associated with the risk and severity of reflux esophagitis, suggesting the organism may have a protective role against gastroesophageal reflux disease.

The efficacy of intravenous contrast-enhanced 16-raw multidetector CT colonography for detecting patients with colorectal polyps in an asymptomatic population in Korea.

Purpose The purpose of this study is to compare the sensitivity of computed tomography (CT) colonography (CTC) with that of colonoscopy for detecting patients with colorectal polyps in an asymptomatic screening population in Korea, thus to evaluate a possibility, whether CTC could be used as a screening tool for colorectal polyps. Methods A total of 241 asymptomatic adults underwent intravenous contrast-enhanced CTC and colonoscopy successively on the same day. Bowel preparation was performed by 4 L of polyethylene glycol (n=172) or 90 mL of sodium phosphate (n=69). The CTC findings were released to the colonoscopists after the first examination of each segment, a procedure known as segmental unblinded colonoscopy, and were used as the reference standard. The diagnostic performance of CTC for colorectal polyps was calculated. Results The per-patient sensitivities of CTC were 68.5% (37/54) and 86.7% (13/15) for polyp ≥6 and ≥10 mm, inferior to those of colonoscopy, 92.6% (50/54) and 100% (15/15), respectively. The per-polyp sensitivities of CTC were 60.4% (61/101) and 72.7% (16/22) for polyp ≥6 and ≥10 mm, respectively. The low sensitivity of CTC was related with flat morphology. CTC detected only 37.5% (9/24) of flat polyps ≥6 mm. Bowel preparation by sodium phosphate further decreased the positive predictive value and specificity than by polyethylene glycol. Conclusions Screening by CTC with asymptomatic population was not promising in Korea despite using advanced CT technology (16-row detector). Bowel preparation was one of the key determinants of the specificity of CTC.

Clinical spectrum of reflux esophagitis among 25,536 Koreans who underwent a health check-up: A nationwide multicenter prospective, endoscopy-based Study

Background Gastroesophageal reflux is a commonly encountered condition, but detailed data on reflux symptoms in Asian countries are lacking. Goals To evaluate the prevalence and to document the clinical spectrum of endoscopic reflux esophagitis (RE). Study A total 25,536 subjects underwent an upper gastrointestinal endoscopic examination as part of a health check, and completed a gastroesophageal reflux questionnaire. Endoscopic findings classified according to the Los Angeles (LA) classification and the data from gastroesophageal reflux questionnaire were analyzed. Results On the basis of endoscopic findings, 2019 subjects (7.91%) were found to have RE: 5.87% in LA-A; 1.84% in LA-B; 0.18% in LA-C; and 0.02% in LA-D. Heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, cough, and epigastric soreness were found to be associated with RE (P<0.05). Heartburn, acid regurgitation, and epigastric soreness were more frequent in LA-B than in LA-A (P<0.05). Epigastric soreness was most bothersome in LA-A and LA-B, and acid regurgitation was most bothersome in LA-C and LA-D (P<0.01). Heartburn, hoarseness, and globus sensation were more frequent in men with RE, and acid regurgitation was most common in women. Conclusions The prevalence of RE was found to be 7.91% in Korea, and the profiles of reflux symptoms were found to depend on grade of RE and sex.

Association between colorectal adenoma and coronary atherosclerosis detected by CT coronary angiography in Korean men; a cross‐sectional study

Background:  Colorectal adenoma and coronary artery disease (CAD) appear to share common risk factors, such as male gender, diabetes mellitus, smoking, and obesity. We investigated the relationship between colorectal adenoma and coronary atherosclerosis, as a risk factor for colorectal adenoma.

Association between Helicobacter pylori Seropositivity and the Coronary Artery Calcium Score in a Screening Population

Background/Aims Helicobacter pylori causes numerous extragastric manifestations, including coronary heart disease. The coronary artery calcification (CAC) score, measured using computed tomography (CT) has been used as a screening test for coronary atherosclerosis. This study investigated the association between H. pylori seropositivity and CAC scores in a screening population. Methods Patients who underwent a health checkup between October 2003 and July 2007 and who did not have a history of ischemic heart disease were enrolled in the study. Subjects were screened with a multidetector CT scan to determine the CAC score and for anti-H. pylori antibody immunoglobulin G; traditional risks for coronary heart disease were evaluated using a structured questionnaire, anthropometric measurements, and laboratory tests. Results Of the 2,029 subjects enrolled (1,295 males), 1,214 (59.8%) subjects were H. pylori positive and 815 were H. pylori negative. There were no significant differences in the baseline characteristics of the seropositive and seronegative patients. When the CAC presence or absence scores were considered, multivariate analysis revealed that H. pylori seropositivity was statistically associated with the presence of CAC and that this association was stronger in the mild CAC score category. Conclusions H. pylori seropositive patients are at a higher risk for coronary atherosclerosis regardless of traditional cardiovascular risk factors. This association is particularly applicable for early coronary atherosclerosis.