Impact of 3-second rule for high confidence assignment on the performance of endoscopists for the real-time optical diagnosis of colorectal polyps.

BACKGROUND: Confusion between high and low confidence decisions in optical diagnosis hinders the implementation of real-time optical diagnosis in clinical practice. We evaluated the effect of a 3-second rule (decision time limited to 3 seconds for a high confidence assignment) in expert and nonexpert endoscopists. METHODS: This single-center prospective study included eight board-certified gastroenterologists. A 2-month baseline phase used standard real-time optical diagnosis for colorectal polyps < 10 mm and was followed by a 6-month intervention phase using optical diagnosis with the 3-second rule. Performance, including high confidence accuracy, and Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) and Simple Optical Diagnosis Accuracy (SODA) thresholds, was measured. RESULTS: Real-time optical diagnosis was performed on 1793 patients with 3694 polyps. There was significant improvement in high confidence accuracy between baseline and intervention phases in the nonexpert group (79.2 % vs. 86.3 %; P = 0.01) but not in the expert group (85.3 % vs. 87.5 %; P = 0.53). Using the 3-second rule improved the overall performance of PIVI and SODA in both groups. CONCLUSIONS: The 3-second rule was effective in improving real-time optical diagnosis performance, especially in nonexperts.

Alcohol consumption and the risk of new-onset uterine leiomyomas: a nationwide population-based study in 2.5 million Korean women aged 20 to 39 years.

BACKGROUND: Uterine leiomyomas are the most common benign tumors in women of childbearing age. Although there are several studies reporting the positive association of drinking alcohol with the incidence of uterine leiomyomas, studies targeting Korean women are lacking. OBJECTIVE: This study aimed to investigate the association between alcohol consumption and the risk of new-onset uterine leiomyomas in Korean women of early reproductive-age. STUDY DESIGN: This was a retrospective nationwide population-based cohort study using the Korean National Health Insurance Service database. Participants comprised 2,512,384 asymptomatic Korean women aged 20 to 39 years who underwent a national health examination from 2009 to 2012. The follow-up period was from the date of the first national health examination to the date of diagnosis of new-onset uterine leiomyomas or December 2018 if no uterine leiomyomas were detected. The diagnosis of uterine leiomyomas required 2 outpatient records within a year or 1 inpatient record of International Classification of Diseases, Tenth Revision (ICD-10) codes of uterine leiomyomas (D25) in the Korean National Health Insurance Service. Exclusion criteria were previously diagnosed uterine leiomyomas during the screening period (January 2002 to the date of first health examination) or uterine leiomyoma diagnosis within 1 year of baseline examination. The associations of alcohol consumption, amount drunk per drinking session, and sustained drinking over time with the risk of new-onset uterine leiomyomas were investigated. RESULTS: Approximately 6.1% of women aged 20 to 39 years were diagnosed with uterine leiomyomas after an average of 4.3 years. Alcohol consumption was associated with an increased incidence of new-onset uterine leiomyomas of 12% to 16% (hazard ratio, 1.12; 95% confidence interval, 1.11-1.14 for mild-to-moderate drinkers; hazard ratio, 1.16; 95% confidence interval, 1.12-1.20 for heavy drinkers). Drinking ≥1 days per week was associated with increased risk of uterine leiomyomas (hazard ratio, 1.11; 95% confidence interval, 1.10-1.12 for drinking 1 day per week; hazard ratio, 1.15; 95% confidence interval, 1.12-1.17 for drinking ≥3 days per week), and the association increased proportionately to the amount of alcohol consumed per drinking session (hazard ratio, 1.17; 95% confidence interval, 1.15-1.19 for ≥7 glasses per drinking session). Women who also reported alcohol consumption in the questionnaire administered 2 years later (sustained drinkers) exhibited a 20% increased risk of new-onset uterine leiomyomas (hazard ratio, 1.20; 95% confidence interval, 1.17-1.22) compared with women who answered that they did not drink alcohol at both times (sustained nondrinkers). In women who discontinued drinking, the risk was 3% (hazard ratio, 1.03; 95% confidence interval, 1.01-1.06), whereas in women who became drinkers, the risk was 14% (hazard ratio, 1.14; 95% confidence interval, 1.11-1.16). CONCLUSION: Having an alcohol drinking habit, the amount of alcohol consumed per drinking session, and sustained drinking over 2 years were significantly associated with the risk of new-onset uterine leiomyomas. Avoiding or discontinuing drinking could lower the risk of new-onset uterine leiomyomas in early reproductive-age women.

Association between Dietary Fiber Intake and Colorectal Adenoma.

Dietary fiber intake has been suggested to decrease the risks of colorectal cancer (CRC) and adenoma. This cross-sectional study aimed to evaluate the association between total dietary fiber intake and colorectal adenoma among asymptomatic Korean adults. Individuals who received a screening colonoscopy between May and December of 2011 were recruited. Multivariable-adjusted logistic regression was used to assess the odds ratios (ORs) and 95% confidence intervals (CIs) of colorectal adenoma. 558 of the 1,716 study participants were diagnosed with colorectal adenoma. No significant association between total dietary fiber intake and colorectal adenoma was found; ORs (95% CIs) for subsequent quintiles compared to the bottom quintile were 1.00 (0.69-1.46), 1.11 (0.73-1.71), 0.97 (0.57-1.65), and 0.88 (0.46-1.71; P for trend = 0.65). Dietary fiber intakes from cereal, fruit, vegetable, or legume weren't associated with colorectal adenoma. When we compared >30 g/d to ≤10 g/d of total dietary fiber intake, OR (95% CI) was 0.32 (0.10-1.02; P for trend = 0.23). In the analyses of advanced or high-risk state and location of adenoma, we didn't observe significant associations. In conclusion, dietary fiber intake was not associated with colorectal adenoma in Korean adults. However, the association for low intake of dietary fiber warrants further investigation.

Impact of comprehensive optical diagnosis training using Workgroup serrAted polypS and Polyposis classification on detection of adenoma and sessile serrated lesion.

OBJECTIVES: Many interventions have been attempted to improve adenoma detection rate (ADR) and sessile serrated lesion detection rate (SDR), and one of these interventions is educational training to recognize polyp characteristics. This study aimed to investigate the change in polyp detection rates of endoscopists before and after comprehensive training through the Gangnam-Real Time Optical Diagnosis (Gangnam-READI) program. METHODS: Fifteen gastroenterologists participated in a 1-year comprehensive training program that consisted of ex vivo and in vivo training that encompasses knowledge and skills in endoscopic characterization of colonic polyps using the Workgroup serrAted polypS and Polyposis (WASP) classification. We evaluated the impact of the training program by comparing the overall and individual ADR and SDR 6 months before and after the training. RESULTS: Overall, 18,280 polyps (9337 adenomas and 855 sessile serrated lesion) were collected. The optical diagnosis training had no significant impact on the difference in ADR after training compared to before training (47.7% vs. 46.5%, P = 0.608). A tendency for a decrease in ADR variance was noted among the endoscopists after training (74.9 vs. 32.7, P = 0.121). The overall pre-training period SDR was 4.5% and showed a statistically significant increase to 5.6%, 8.0%, and 7.1% in the first and second half of the training period, and post-training period, respectively (P = 0.003). The optical diagnosis training did not decrease variance in SDR (8.9 vs. 8.8, P = 0.985). CONCLUSION: Comprehensive optical diagnosis training with WASP classification has a significant impact on increasing the overall SDR of expert endoscopists.

Improved Accuracy in Optical Diagnosis of Colorectal Polyps Using Convolutional Neural Networks with Visual Explanations.

BACKGROUND & AIMS: Narrow-band imaging (NBI) can be used to determine whether colorectal polyps are adenomatous or hyperplastic. We investigated whether an artificial intelligence (AI) system can increase the accuracy of characterizations of polyps by endoscopists of different skill levels. METHODS: We developed convolutional neural networks (CNNs) for evaluation of diminutive colorectal polyps, based on efficient neural architecture searches via parameter sharing with augmentation using NBIs of diminutive (≤5 mm) polyps, collected from October 2015 through October 2017 at the Seoul National University Hospital, Healthcare System Gangnam Center (training set). We trained the CNN using images from 1100 adenomatous polyps and 1050 hyperplastic polyps from 1379 patients. We then tested the system using 300 images of 180 adenomatous polyps and 120 hyperplastic polyps, obtained from January 2018 to May 2019. We compared the accuracy of 22 endoscopists of different skill levels (7 novices, 4 experts, and 11 NBI-trained experts) vs the CNN in evaluation of images (adenomatous vs hyperplastic) from 180 adenomatous and 120 hyperplastic polyps. The endoscopists then evaluated the polyp images with knowledge of the CNN-processed results. We conducted mixed-effect logistic and linear regression analyses to determine the effects of AI assistance on the accuracy of analysis of diminutive colorectal polyps by endoscopists (primary outcome). RESULTS: The CNN distinguished adenomatous vs hyperplastic diminutive polyps with 86.7% accuracy, based on histologic analysis as the reference standard. Endoscopists distinguished adenomatous vs hyperplastic diminutive polyps with 82.5% overall accuracy (novices, 73.8% accuracy; experts, 83.8% accuracy; and NBI-trained experts, 87.6% accuracy). With knowledge of the CNN-processed results, the overall accuracy of the endoscopists increased to 88.5% (P < .05). With knowledge of the CNN-processed results, the accuracy of novice endoscopists increased to 85.6% (P < .05). The CNN-processed results significantly reduced endoscopist time of diagnosis (from 3.92 to 3.37 seconds per polyp, P = .042). CONCLUSIONS: We developed a CNN that significantly increases the accuracy of evaluation of diminutive colorectal polyps (as adenomatous vs hyperplastic) and reduces the time of diagnosis by endoscopists. This AI assistance system significantly increased the accuracy of analysis by novice endoscopists, who achieved near-expert levels of accuracy without extra training. The CNN assistance system can reduce the skill-level dependence of endoscopists and costs.

Dietary pattern and its association with right-colonic diverticulosis.

BACKGROUND AND AIM: In East Asia, colonic diverticulosis develops most commonly in the right colon and is known to have different characteristics compared with left-sided one. This study was designed to investigate whether right-colonic diverticulosis is associated with posteriori dietary patterns. METHODS: We retrospectively reviewed medical records of prospectively collected cohort that received health check-up in Korea between May 2011 and January 2012. Their anthropometric data, biochemical results, medication history, underlying diseases, colonoscopic findings, and dietary data obtained from semi-quantitative food-frequency questionnaire were analyzed. Three dietary patterns were identified using factor analysis: healthy dietary pattern (vegetables, fish, seaweed, fruits, and beans), meat dietary pattern (red meat, processed meat/fish, fried noodle, poultry, and cephalopods), and snack dietary pattern (bread, sweets, dairy products, nuts, and rice cake). RESULTS: Out of the total 1911 patients, 203 (10.6%) had right-colonic diverticulosis, 21 (1.1%) had pan-colonic diverticulosis, and 12 (0.6%) had left-colonic diverticulosis. Among the total, none of the three patterns were associated with right-colonic diverticulosis, under adjustment with age, gender, body mass index, metabolic syndrome, and total energy intake. However, among women, meat dietary pattern was positively associated with right-colonic diverticulosis (odds ratio 1.866, 95% confidence interval: 1.0983-3.173, P = 0.021). CONCLUSION: This study demonstrated that meat dietary pattern is positively associated with right-colonic diverticulosis among women.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort.

BACKGROUND AND AIM: While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence. METHODS: Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA. RESULTS: During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm2 increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm2 increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA. CONCLUSION: Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Multidirectional Colonoscopy Quality Improvement Increases Adenoma Detection Rate: Results of the Seoul National University Hospital Healthcare System Gangnam Center Colonoscopy Quality Upgrade Project (Gangnam-CUP).

BACKGROUND: To prevent colorectal cancer, high-quality colonoscopy is advocated, undertaken by endoscopists with high adenoma detection rates (ADRs). Despite reports that various factors may impact ADRs, the significance of such factors is still unclear. AIMS: The analysis was aimed at quality-oriented interventions for boosting ADRs. METHODS: Study enrollees were adults subjected to screening colonoscopy between September 2013 and August 2016 at the Gangnam Center of Seoul National University Hospital Healthcare System. The investigation entailed six periods (P1-6) of 6 months each, during which serial multidirectional quality improvement efforts were instituted. In particular, we sought to further educate endoscopists, provide feedback on individual ADRs, and introduce a split-dose regimen, gauging results via the Boston Bowel Preparation Score. Changes in polyp detection rates (PDRs) and ADRs were then analyzed. RESULTS: A total of 13,430 colonoscopies were undertaken by 15 experienced endoscopists. Overall, the ADR increased from 45.6% (P1) to 48.2% (P6, p < 0.001). The PDR, ADR, and advanced adenoma detection rate (AdvADR) showed the greatest increases between P3 and P4 [PDR 67.8% → 71.2% (p < 0.001); ADR 44.1% → 47.7% (p = 0.001); AdvADR 2.3% → 3.3% (p = 0.028)] in keeping with the introduction of a split-dose regimen. The sessile serrated adenoma detection rate (SSADR) increased substantially from 2.1% (P1) to 7.9% (P6, p < 0.001), with the largest gain between P1 and P2, just after education (p = 0.023). CONCLUSIONS: Successful quality improvement in colonoscopy was achieved through comprehensive multidirectional efforts in education, feedback, and enhanced bowel preparation. Achieving high-level bowel preparation was paramount in ADR improvement. The SSADR was improved through education.

Improved Real-Time Optical Diagnosis of Colorectal Polyps Following a Comprehensive Training Program.

BACKGROUND & AIMS: The optimal training method for endoscopic characterization of colorectal polyps using narrow-band imaging is uncertain, and sessile serrated lesions (SSLs) optical diagnosis data are lacking. We aimed to evaluate a comprehensive training program for real-time optical diagnosis of colorectal polyps, including SSLs. METHODS: We performed a single-institution prospective study of 15 endoscopists trained with the Workgroup Serrated Polyps and Polyposis classification system. After the first phase of in vivo optical diagnosis, their performances were evaluated. After re-education for insufficient competency, they began the second phase. The learning curves and performance on 2 preservation and incorporation of valuable endoscopic innovations benchmarks were assessed. RESULTS: A total of 7294 polyps, including 486 SSLs, were diagnosed in real-time. The overall accuracy improved from 73.5% in the first phase to 77.1% in the second. The accuracy with high confidence was 79.4% and 85.1% in the first and second phases, respectively. In the first and second phases, the negative predictive values for diminutive neoplastic polyps were 82.1% and 92.5%, respectively, and concordances of the surveillance intervals were 80.7% and 89.7%, respectively. Eight endoscopists achieved the preservation and incorporation of valuable endoscopic innovations benchmarks after the second phase compared with none after the first. In contrast, the high confidence rate decreased from 74.6% to 70.2% as training progressed. CONCLUSION: A comprehensive training program for real-time optical diagnosis significantly improved performance and reduced individual variability in less-experienced endoscopists. ClinicalTrials.gov no: NCT02516748.

Visceral obesity as a risk factor for colorectal adenoma occurrence in surveillance colonoscopy.

BACKGROUND AND AIMS: The aim of this study was to examine the prospective association between visceral obesity and the incidence and recurrence of colorectal adenoma. METHODS: We conducted a cohort study involving 2244 participants between 2006 and 2007. The study participants were prospectively followed until 2014 according to the initial colonoscopy and histopathology findings. Incident and recurrent colorectal adenoma groups were defined as individuals with a positive follow-up colonoscopy result from the normal results and adenoma groups, respectively, at the baseline colonoscopy. RESULTS: Among the 1163 patients (51.8%) who received a follow-up colonoscopy, 509 (43.8%) and 654 (56.2%) were grouped into the normal and adenoma cohorts. Colorectal adenomas occurred in 592 patients (50.9%) during the median period of 43 months, with an incident adenoma prevalence of 39.1% and a recurrent adenoma prevalence of 60.1%. An increase in the visceral adipose tissue (VAT) area was associated with a higher incidence of adenoma (highest quintile vs lowest quintile of the VAT hazard ratios [HRs], 2.16; 95% confidence interval [CI], 1.26-3.71; HR 1.32 [per 1-standard deviation]; 95% CI, 1.10-1.60) in the multivariable analysis. Increases in body mass index and waist circumference were associated with recurrent adenomas (HR 1.33 [per 1 kg/m2], 95% CI, 1.18-1.46; HR 1.04 [per 1 cm], 95% CI, 1.01-1.07, respectively) in the multivariate analysis. CONCLUSION: A higher VAT area was dose-dependently associated with a higher risk of incident adenoma. Furthermore, increases in body mass index and waist circumference as surrogate markers of abdominal obesity were associated with a higher risk of recurrent adenoma.

Analysis of Pregnancy Outcomes among Interracial Couples in Korea.

Although the prevalence of interracial marriages in Korea is increasing, little is known regarding the pregnancy outcomes of interracial couples. The aim of this study was to investigate the differences in pregnancy outcomes between Korean and interracial Korean-foreign couples. Data for infants born in 2011 and 2012 were obtained from the national birth registry of the Korean Statistical Office. The couples were subdivided into Korean father-Korean mother, Korean father-foreign mother, and foreign father-Korean mother groups. Pregnancy outcomes included neonates with low birth weight (< 2,500 g) and those with high birth weight (> 4,000 g). In 2010 and 2011, 888,447 Korean father-Korean mother, 36,024 Korean father-foreign mother, and 4,955 foreign father-Korean mother neonates were delivered in Korea. After adjustment for parental age, educational level, parity, gestational age at delivery, and neonatal sex, the birth weights were found to be different between groups, with the highest number of foreign father-Korean mother and lowest number of Korean father-foreign mother pregnancies. Based on multivariate logistic regression analysis, the risk of low and large birth weights was higher in the Korean father-foreign mother and foreign father-Korean mother groups, respectively, compared with that in the Korean father-Korean mother group. There are significant differences in pregnancy outcomes including birth weights between Korean and interracial Korean-foreign couples.

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 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.

Hepatic fat, not visceral fat, is associated with gallbladder polyps: a study of 2643 healthy subjects.

BACKGROUND AND AIM: Gallbladder polyps (GBPs) appear to be strongly associated with obesity and metabolic disease. To date, the relationship between GBPs and fatty liver has not been adequately evaluated. The aim of the present study was to investigate whether GBPs are associated with fatty liver, which is an ectopic regional fat deposit, independent of visceral adipose tissue (VAT). METHODS: A cross-sectional study using 2643 health checkup subjects (961 patients with GBP and 1682 age- and sex-matched healthy controls) was conducted. The subjects underwent various laboratory tests, abdominal fat computed tomography (CT), and hepatic ultrasonography. RESULTS: The mean age of the subjects was 51.4 ± 8.3 years, and 74.1% were male. GBPs were significantly associated with fatty liver. Multivariate regression analysis revealed that GBPs were significantly associated with the presence of fatty liver (odds ratio [OR] 1.23, 95% confidence interval [CI]: 1.02-1.48), and adjusting for the homeostatic metabolic assessment index had little effect on this association (OR 1.23, 95% CI: 1.02-1.48). Additionally, GBPs remained significantly associated with the presence of fatty liver after adjustments for CT-measured VAT and subcutaneous adipose tissue (OR 1.24, 95% CI: 1.03-1.50). The degree of fatty liver showed an independent (OR 1.37 95% CI: 1.03-1.80) and dose-dependent relationship (moderate-severe fatty liver: OR 1.55 95% CI: 1.07-2.23, P for trend = 0.014) with large GBPs (≥ 5 mm). CONCLUSION: Fatty liver, an ectopic regional fat deposit, was found to be closely associated with GBPs independent of known metabolic risk factors, insulin resistance, and CT-measured VAT, confirming a relevant clinical relationship between the two diseases.

Comparison of Narrow Band Imaging and Fujinon Intelligent Color Enhancement in Predicting Small Colorectal Polyp Histology.

BACKGROUND: There are limited data on the performance of narrow band imaging (NBI) and Fujinon intelligent color enhancement (FICE) for differentiating polyp histologies. AIMS: The aim of this study was to compare the diagnostic performances of NBI and FICE in differentiating neoplastic from non-neoplastic colorectal polyps <10 mm during screening colonoscopy. METHODS: A total of 955 average-risk adults undergoing screening colonoscopies were randomly allocated to NBI or FICE groups. Four board-certified staff endoscopists without prior experience using NBI or FICE participated. The main outcomes of this study were overall accuracy, sensitivity, and specificity of FICE and NBI in identifying neoplastic polyps. RESULTS: There was no significant difference in the number of subjects with adenoma between the NBI (143/475, 30.1 %) and FICE groups (139/480, 29.0 %) (after excluding adenoma ≥1 cm) (P > 0.05). The overall accuracy of NBI was 81.0 %, compared with 81.4 % for FICE (P = 0.867). The overall sensitivity and specificity of NBI and FICE were 84.6 and 78.0 % (P = 0.054); 75.1 and 86.5 % (P = 0.009), respectively. For polyps measuring ≤5 mm, the accuracy was 79.4 % for NBI and 80.1 % for FICE (P = 0.835; sensitivity 81.9 vs. 74.5 %, P = 0.064; specificity 75.7 vs. 88.4 %, P = 0.006). CONCLUSIONS: The overall accuracy of NBI and FICE was similar for differentiating small polyp histologies during screening colonoscopy. However, better results should be achieved before using NBI or FICE as real-time optical biopsy of colorectal polyps in screening colonoscopy.

The role of leptin in gastric cancer: clinicopathologic features and molecular mechanisms.

Obesity is associated with certain types of cancer, including gastric cancer. However, it is still unclear whether obesity-related cytokine, leptin, is implicated in gastric cancer. Therefore, we aimed to investigate the role of leptin in gastric cancer. The expression of leptin and its receptor, Ob-R, was assessed by immunohistochemical staining and was compared in patients with gastric adenoma (n=38), early gastric cancer (EGC) (n=38), and advanced gastric cancer (AGC) (n=38), as a function of their clinicopathological characteristics. Gastric cancer cell lines were studied to investigate the effects of leptin on the signal transducer and activator of transcription-3 (STAT3) and extracellular receptor kinase 1/2 (ERK1/2) signaling pathways using MTT assays, immunoblotting, and inhibition studies. Leptin was expressed in gastric adenomas (42.1%), EGCs (47.4%), and AGCs (43.4%). Ob-R expression tended to increase from gastric adenoma (2%), through EGC (8%), to AGC (18%). Leptin induced the proliferation of gastric cancer cells by activating STAT3 and ERK1/2 and up-regulating the expression of vascular endothelial growth factor (VEGF). Blocking Ob-R with pharmacological inhibitors and by RNAi decreased both the leptin-induced activation of STAT3 and ERK1/2 and the leptin-induced expression of VEGF. Leptin plays a role in gastric cancer by stimulating the proliferation of gastric cancer cells via activating the STAT3 and ERK1/2 pathways.

Factors that determine prolonged cecal intubation time during colonoscopy: impact of visceral adipose tissue.

OBJECTIVE: Various factors including age, sex, body mass index (BMI) and history of operation have been linked to the colonoscopic intubation time. The aims of this study were to identify the factors predicting cecal intubation time (CIT) and to evaluate the effect of the visceral adipose tissue (VAT) area on CIT. MATERIAL AND METHODS: A total of 1386 consecutive subjects who underwent colonoscopy and abdominal CT on the same day for a health checkup at a single health care center in Korea from August to December 2011 were studied prospectively. Age, sex, BMI, height, waist circumference, history of operation, symptoms of irritable bowel syndrome, bowel preparation status, experience of colonoscopists, VAT amount on abdominal CT and time required to reach the cecum were analyzed. RESULTS: The mean age of the subjects was 53.0 ± 9.6 years, and 63.5% were male. The median CIT was 271 s. Univariate analyses showed that female gender, old age, shorter height, lower BMI, prior history of surgery and lower VAT were associated with longer CIT. To adjust for confounding effects of the gender, we investigated the genders separately in multivariate analysis. Older age and lower VAT were associated with prolonged CIT. However, the significance of association of VAT on prolonged CIT disappeared in women. CONCLUSION: This study demonstrates that CIT is prolonged by lower VAT area in men. This is the first study to demonstrate a direct association between VAT area and CIT.

Dietary intake is associated with the prevalence of uterine leiomyoma in Korean women: A retrospective cohort study.

OBJECTIVE: Uterine leiomyoma (UL), the most prevalent benign gynecologic tumor among reproductive-aged women, lacks sufficient research on the potential association between dietary intake and its occurrence in Korean women. Addressing this research gap, this study aims to evaluate the potential link between dietary intake and the prevalence of UL in Korean women. METHODS: In this cross-sectional study, a cohort of 672 women, aged 23 to 73, were enrolled, with 383 (57%) being premenopausal. Dietary intake was assessed using a validated food frequency questionnaire (FFQ), and UL presence was determined through ultrasonography. The analysis focused exclusively on items within ten categories, including vegetables/fruit, vegetables, fruits, red meat, processed meat, poultry, fish, dairy product, milk, and alcohol. Multiple logistic regression models were employed to explore the relationship between dietary intake and the prevalence of UL, calculating odds ratios (ORs) and 95% confidence intervals (CIs) while adjusting for confounding factors. RESULTS: Within the total cohort, 220 (32.7%) women were diagnosed with UL. High intakes of fish and poultry showed an association with higher UL prevalence. Odds ratios (95% CIs) for the upper quartiles compared to the lower quartiles were 1.68 (1.01-2.81; p trend = 0.05) for fish intake and 1.87 (1.11-3.17; p trend = 0.06) for poultry intake. Conversely, an inverse relationship emerged between dairy product intake and UL prevalence, with an odds ratio of 0.58 (95% CI 0.35-0.96; p trend = 0.05). Stratifying the analysis by menopausal status revealed a parallel pattern, with heightened UL prevalence with fish intake and reduced prevalence with dairy product intake. However, the link between poultry intake and UL prevalence was primarily observed among postmenopausal women. Among premenopausal women, elevated vegetable intake was linked to a decreased UL prevalence (OR 0.45, 95% CI 0.21-0.97 for top vs. bottom quartiles; p trend = 0.01). CONCLUSION: We found that high consumption of fish and poultry, coupled with low intake of dairy products, correlated with an elevated prevalence of UL. Furthermore, vegetable intake exhibited an inverse relationship with UL prevalence, particularly among premenopausal women.

Genetic and Metabolic Characteristics of Lean Nonalcoholic Fatty Liver Disease in a Korean Health Examinee Cohort.

Background/Aims: The pathophysiology of lean nonalcoholic fatty liver disease (NAFLD) is unclear but has been shown to be associated with more diverse pathogenic mechanisms than that of obese NAFLD. We investigated the characteristics of genetic or metabolic lean NAFLD in a health checkup cohort. Methods: This retrospective cross-sectional study analyzed single nucleotide polymorphism data for 6,939 health examinees. Lean individuals were categorized according to a body mass index cutoff of 23 kg/m2. Single nucleotide polymorphisms were analyzed using genotyping arrays. Results: The prevalence of lean NAFLD was 21.6% among all participants with NAFLD, and the proportion of lean NAFLD was 18.5% among lean participants. The prevalence of metabolic syndrome and diabetes among lean patients with NAFLD was 12.4% and 10.4%, respectively. Lean NAFLD appeared to be metabolic-associated in approximately 20.1% of patients. The homozygous minor allele (GG) of PNPLA3 (rs738409) and heterozygous minor alleles (CT, TT) of TM6SF2 (rs58542926) were associated with lean NAFLD. However, the prevalence of fatty liver was not associated with the genetic variants MBOAT7 (rs641738), HSD17B13 (rs72613567), MARC1 (rs2642438), or AGXT2 (rs2291702) in lean individuals. Lean NAFLD appeared to be associated with PNPLA3 or TM6SF2 genetic variation in approximately 32.1% of cases. Multivariate risk factor analysis showed that metabolic risk factors, genetic risk variants, and waist circumference were independent risk factors for lean NAFLD. Conclusions: In a considerable number of patients, lean NAFLD did not appear to be associated with known genetic or metabolic risk factors. Further studies are required to investigate additional risk factors and gain a more comprehensive understanding of lean NAFLD.

Quantitative estimation of the total sulfide concentration in live tissues by two-photon microscopy.

Hydrogen sulfide (H2S) is a newly recognized transmitter, which protects various organs from oxidative stress. In this article, we report a ratiometric two-photon probe, TFCA, which can be excited by 750 nm femtosecond pulses, shows a 110-fold increase in the intensity ratio upon reaction with HS(-) and high selectivity for HS(-) and can visualize the total sulfide ([H2S] + [HS(-)]) distribution in live tissue by two-photon microscopy (TPM). We also developed a kinetic method to quantitatively estimate the total sulfide concentration ([H2S] + [HS(-)]) in live tissues. The kinetic method allowed us to measure the observed rate constants (kobs) for the sulfide-induced deazidation reaction of TFCA in live cells and tissues using TPM. The total sulfide concentration was calculated by using kobs = k2[HS(-)], with the k2 value determined in HEPES/EtOH (1/1, pH = 7.2), and [H2S]/[HS(-)] = [H(+)]/Ka. The total sulfide concentration was found to be nearly zero in HeLa cells and 4-7 µM in rat colon tissues.