Sun Young Yang

Prevalence and risk of colorectal adenoma in asymptomatic Koreans aged 40–49 years undergoing screening colonoscopy

Background and Aim:  Colorectal cancer screening is recommended for average‐risk persons beginning at age 50. However, information about the incidence and risk factors of precursor adenoma in preceding decades is limited. The aim of this study was to determine the prevalence and risk factors of colorectal adenoma in persons aged 40–49 years and to compare the data with those aged 30–39 years and 50–59 years.

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.

Seroprevalence of Hepatitis A and Associated Socioeconomic Factors in Young Healthy Korean Adults

BACKGROUND/AIMS An epidemiologic shift of hepatitis A virus (HAV) seroprevalence is expected due to an improvement in socioeconomic status in young adults in Korea. We investigated the age-specific seroprevalence and socioeconomic factors associated with HAV seropositivity in young, healthy Korean adults. METHODS Between March 2009 and February 2010, a total of 5,051 persons from 20 to 49 years of age presenting for a health check-up were included and responded to a questionaire. The seroprevalence of HAV was investigated by measuring immunoglobulin G (IgG) anti-HAV. A total of 984 pairs of cases and age- and sex-matched controls were analyzed for associated socioeconomic factors. RESULTS The prevalence of seropositive HAV was 6.2% in the 20 to 29 age range, 33.1% in the 30 to 39 range and 82.4% in the 40 to 49 range (p<0.001). There were no significant differences in any group according to gender. A multivariate analysis for paired cases indicated that HAV seropositivity was significantly higher in the low monthly income (below five million won, approximately 4,300 dollars) group and the Helicobacter pylori (H. pylori)-positive group (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.27-2.14; p<0.001; OR, 1.45; 95% CI, 1.19-1.76; p<0.001, respectively). CONCLUSIONS HAV seropositivity in young adults presenting for a health checkup appears to be decreasing, and the prevalence was significantly higher in the low monthly income group and the H. pylori-positive group.

ATP-Binding Cassette Sterol Transporters Are Differentially Expressed in Normal and Diseased Human Gallbladder

Background and AimsGallbladder epithelial cells (GBEC) are exposed to high cholesterol concentrations in bile, and export cholesterol via an ATP-binding cassette (ABC) transporter-mediated pathway in vitro. These findings suggest that aberrant expression and/or function of ABC sterol transporters may be associated with cholesterol-related gallbladder diseases (CAGD). In this study, we investigated the relative levels of the sterol transporters ABCA1, ABCG5, and ABCG8 in human gallbladders in CAGD, and the relationship between ABCA1 and inflammation.MethodsExpression of ABCA1, ABCG5, and ABCG8 was evaluated in 31 gallbladders with CAGD and 6 normal gallbladders by western blotting and immunohistochemistry. RT-PCR was used to measure ABCA1 mRNA expression. To investigate the relationship between ABCA1 and inflammation, wWestern blots were performed on cultured dog GBEC treated with lipopolysaccharide (LPS) using an anti-ABCA1 antibody.ResultsImmunohistochemistry showed ABCA1 to be localized predominantly to the basolateral membrane, while ABCG8 formed a diffuse intracellular pattern at the apical pole of human GBEC. ABCA1 and ABCG8 expression was more prominent in GBEC that were surrounded by cholesterol-laden macrophages. ABCA1 and ABCG8 expression was increased in gallbladders with CAGD. Western blots showed increased ABCA1, ABCG5, and ABCG8 expression in CAGD. ABCA1 mRNA levels were increased in all gallbladders with CAGD. LPS treatment of cultured dog GBEC enhanced ABCA1 expression.ConclusionsThe sterol transporters ABCA1, ABCG5, and ABCG8 may play a role in the pathogenesis of human CAGD. Inflammation appears to be a key factor that increases ABCA1 expression and activity in the human gallbladder.

Risk of progression for incidental small subepithelial tumors in the upper gastrointestinal tract.

BACKGROUND AND STUDY AIMS Subepithelial tumor is a relatively common finding in upper gastrointestinal endoscopy. This study aimed to evaluate the natural course of incidentally detected small subepithelial tumors in the upper gastrointestinal tract and to analyze risk factors for increase in the size of such tumors. PATIENTS AND METHODS Medical records of 1684 patients with subepithelial tumors in the upper gastrointestinal tract incidentally detected between 2004 and 2013 were retrospectively reviewed. If serial follow-up endoscopy showed significant size increase, endoscopic or surgical resection was recommended because of possibility of malignant change. RESULTS 954 participants with subepithelial tumors underwent serial upper gastrointestinal endoscopy for a period > 6 months. Initial mean size of subepithelial tumors was 8.7 mm (range 1 - 35 mm). During a mean follow-up of 47.3 months (range 6 - 118 months), lesion size was unchanged in 920 participants (96.4 %), and in 34 participants (3.6 %) lesions had increased at least 25 % in diameter (mean increment 6.2 mm, range 2 - 15 mm). Subepithelial tumors with overlying mucosal changes (hyperemia, erosion, or ulcer) had a significantly higher risk of increasing in size (odds ratio [OR] = 3.61, 95 % confidence interval [95 %CI] 1.06 - 12.28). Growth rates (size increment per year) for enlarging lesions were significantly correlated with initial size (r = 0.44, P = 0.009). CONCLUSIONS Most incidentally detected small subepithelial tumors in the upper gastrointestinal tract showed no size change during follow-up. Thus, regular follow-up with serial endoscopy may be sufficient for small subepithelial tumors (< 2 cm) with intact overlying mucosa.

The Influence of Metabolic Factors for Nonalcoholic Fatty Liver Disease in Women

Background/Aims. Women after menopause have increased insulin resistance and visceral fat, which may increase the prevalence of nonalcoholic fatty liver disease (NAFLD). However, the pathogenesis of NAFLD in women has not been clearly defined. In this study, we aimed to determine the risk factors for NAFLD in women. Methods. A retrospective cohort study was conducted. Women who underwent abdominal ultrasonography and blood sampling for routine health check-ups were recruited. Results. Among 1,423 subjects, 695 women (48.9%) were in a menopausal state. The prevalence of NAFLD was higher in postmenopausal women than in premenopausal women (27.2% versus 14.4%, P < 0.001). In premenopausal women, low HDL-cholesterol, central obesity, and homeostasis model assessment-estimated insulin resistance showed a significant association with the increased risk of NAFLD in multivariate analysis. In postmenopausal women, the presence of diabetes, triglyceridemia, and central obesity showed a significant association with the risk of NAFLD. The presence of menopause and hormone replacement therapy in postmenopausal women were not risk factors for NAFLD. Conclusions. Our findings showed different metabolic factors for NAFLD in pre- and postmenopausal women. However, the key issues are the same: central obesity and insulin resistance. These results reemphasize the importance of metabolic factors irrespective of menopausal status in the pathogenesis of NAFLD in women.

Dietary protein and fat intake in relation to risk of colorectal adenoma in Korean.

Abstract Consumption of red meat and alcohol are known risk factors for colorectal cancer, but associations for dietary fat remain unclear. We investigated the associations of dietary fat, protein, and energy intake with prevalence of colorectal adenoma. We performed a prospective cross-sectional study on asymptomatic persons who underwent a screening colonoscopy at a single center during a routine health check-up from May to December 2011. Dietary data were obtained via a validated Food Frequency Questionnaire (FFQ), assisted by a registered dietician. We also obtained information on alcohol consumption and smoking status, and measured metabolic syndrome markers including abdominal circumference, blood pressure, fasting glucose, serum triglyceride and high-density lipoprotein cholesterol. We calculated odds ratio (OR) and 95% confidence interval (CI) to evaluate the associations using the polytomous logistic regression models. As a secondary analysis, we also conducted a matched analysis, matched by age and sex (557 cases and 557 non-cases). The study sample included 557 cases (406 males and 151 females) with histopathologically confirmed colorectal adenoma, and 1157 controls (650 males and 507 females). The proportion of advanced adenoma was 28.1% of men and 18.5% of female, respectively. Although vegetable protein intake was inversely associated with the prevalence of colorectal adenoma, further adjustment for potential confounding factors attenuated the association, resulting in no significant associations. There were no significant associations between dietary fat intake and colorectal adenoma in energy-adjusted models. For vegetable protein in women, the OR for the comparison of those in the highest tertile with those in the lowest tertile was 0.47 (95% CI 0.25–0.91, P for trend = 0.07) after adjustment for total energy intake. However, after controlling for metabolic syndrome markers, body mass index, smoking status, alcohol consumption, and family history of colorectal adenoma, which were all significantly high in the colorectal adenoma patients group, the association became attenuated (OR 0.54, 95% CI 0.27–1.11, P for trend = 0.13). In conclusion, we did not observe the significant associations for intakes of total energy, total, animal and vegetable fats, and total, animal and vegetable proteins in relation to colorectal adenoma prevalence.

The Relationship Between Colonoscopy Procedure Order and Adenoma Detection Rates: A Prospective Study.

Goals: The aim of this study was to prospectively assess the effects of the order of colonoscopic procedures and other possible factors on the adenoma detection rate (ADR). Background: There have been conflicting studies regarding the timing or order of a colonoscopy and its ability to detect adenomas. Study: Between March 2011 and July 2011, consecutive colonoscopies were prospectively performed by 7 board-certified staff endoscopists at the Seoul National University Hospital Healthcare System Gangnam Center. The primary outcome was the overall ADR according to the procedure order of the colonoscopies, and the secondary outcome was the identification of other possible factors influencing the ADR. Results: A total of 1908 colonoscopies were analyzed. The detection rate was 56.5% for all polyps and 37.3% for adenomas. The ADR increased as the performance order of the colonoscopy increased and was highest for the third procedure (43.4%). However, the ADR of the remaining procedures, including later procedures, was similar throughout the workday. In the multivariable analysis, the ADR was significantly associated with older age, male sex, high body mass index, personal history of colorectal polyps, long withdrawal time, and an experienced endoscopist. However, the colonoscopy procedure order was not significantly associated with the ADR. Conclusions: The ADR was stable according to the procedure order for the later procedures of the workday in a setting of moderate daily procedure volumes. The withdrawal time and experience level of the endoscopist were more important than the procedure order in detecting adenomas by colonoscopy.

Risk Factors for Gastric Tumorigenesis in Underlying Gastric Mucosal Atrophy

Background/Aims Atrophic gastritis is considered a premalignant lesion. We aimed to evaluate the risk factors for gastric tumorigenesis in underlying mucosal atrophy. Methods A total of 10,185 subjects who underwent upper gastrointestinal endoscopy between 2003 and 2004 were enrolled in this retrospective cohort study. Follow-up endoscopy was performed between 2005 and 2014. Atrophic gastritis and intestinal metaplasia were assessed by endoscopy using the Kimura-Takemoto classification. Helicobacter pylori infection was evaluated based on serum immunoglobulin G antibody levels, the rapid urease test, or the urea breath test. Results Atrophic gastritis was confirmed in 3,714 patients at baseline; 2,144 patients were followed up for 6.9 years, and 1,138 exhibited increased atrophy. A total of 69 subjects were diagnosed with gastric neoplasm during follow-up (35 adenoma and 34 carcinoma). Age ≥55 years (hazard ratio [HR], 1.234), alcohol consumption (HR, 1.001), and H. pylori infection (HR, 1.580) were associated with increased mucosal atrophy. The risk factors for gastric neoplasm in underlying mucosal atrophy were age ≥55 years (HR, 2.582), alcohol consumption (HR, 1.003), extent of mucosal atrophy (HR, 2.285 in C3-O1; HR, 4.187 in O2–O3), and intestinal metaplasia (HR, 2.655). Conclusions Extent of atrophy, intestinal metaplasia, and alcohol consumption are significant risk factors for gastric neoplasm in underlying mucosal atrophy.

High Salt Intake Is Associated with Atrophic Gastritis with Intestinal Metaplasia

Background: Although several studies have investigated excessive salt intake as a risk factor for gastric precancerous lesions, such as atrophic gastritis and intestinal metaplasia, the evidence is insufficient to make a conclusion. We evaluated the association between gastric precancerous lesions and salt intake. Methods: From 2008 to 2015, the medical records of 728 subjects who underwent upper gastrointestinal endoscopy and sodium excretion in 24-hour urine tests were retrospectively reviewed. Sixty-six subjects were excluded due to diuretics use (n = 55), diagnosis with a gastric neoplasm (n = 4), or the cases of intestinal metaplasia in the absence of atrophy (n = 7), so 662 subjects were included. Atrophic gastritis and intestinal metaplasia were diagnosed by endoscopic findings. The subjects were grouped into three levels by tertiles of 24-hour urine sodium excretion. Results: A total of 192 (29.0%) had atrophic gastritis without intestinal metaplasia and 112 (16.9%) had atrophic gastritis with intestinal metaplasia. A total of 276 subjects (61.5%) were infected with Helicobacter pylori (H. pylori). In multivariate analyses, H. pylori infection [OR = 14.17; 95% confidence interval (CI), 7.12–28.22) was associated with atrophic gastritis without intestinal metaplasia. Highest levels of sodium excretion (OR = 2.870; 95% CI, 1.34–6.14), heavy smoking (≥20 pack-years) (OR = 2.75; 95% CI, 1.02–7.39), and H. pylori infection (OR = 3.96; 95% CI, 2.02–7.76) were associated with atrophic gastritis with intestinal metaplasia. Conclusions: Our endoscopy-based study suggested that high salt intake could be associated with an increased risk of atrophic gastritis with intestinal metaplasia. Impact: Low salt diet might be helpful to prevent gastric carcinogenesis. Cancer Epidemiol Biomarkers Prev; 26(7); 1133–8. ©2017 AACR.