Boc Protection for Diamine-Appended MOF Adsorbents to Enhance CO2 Recyclability under Realistic Humid Conditions.

Among the various metal-organic framework (MOF) adsorbents, diamine-functionalized Mg2(dobpdc) (dobpdc4- = 4,4-dioxidobiphenyl-3,3'-dicarboxylate) shows remarkable carbon dioxide removal performance. However, applying diamine-functionalized Mg2(dobpdc) in practical applications is premature because it shows persistent performance degradation under real flue gas conditions containing water vapor owing to diamine loss during wet cycles. To address this issue, we employed hydrophobic carbonate compounds to protect diamine groups in een-Mg2(dobpdc) (een-MOF, een = N-ethylethylenediamine). tert-Butyl dicarbonate (Boc) reacted rapidly with diamines at the pore openings of MOF particles to form dense secondary and tertiary hydrophobic amines, effectively preventing moisture ingress. The Boc-protected een-MOF-Boc1 maintained excellent CO2 adsorption even under simulated flue gas conditions containing 10% H2O. This observation indicates that Boc protection renders een groups intact during repeated wet cycles, suggesting that Boc-protected een groups are resistant to replacement by water molecules. To increase the practicability of the MOF adsorbent, we fabricated een-MOF/PAN-Boc1 composite beads by shaping MOF particles with polyacrylonitrile (PAN). Notably, the composite beads maintained their CO2 adsorption performance even after repeating the temperature swing adsorption process more than 150 times in 10% water vapor. Furthermore, breakthrough tests showed that the dynamic CO2 separation performance was retained under humid conditions. These results demonstrate that Boc protection provides an easy and effective way to develop promising adsorbents with high CO2 adsorption capacity, long-term durability, and the properties required for postcombustion applications.

Serum 25-Hydroxyvitamin D Levels and Risk of Colorectal Cancer: An Age-Stratified Analysis.

BACKGROUND & AIMS: The role of circulating 25-hydroxyvitamin D (25(OH)D) in the prevention of early-onset colorectal cancer (CRC) in young adults aged <50 years is uncertain. We evaluated the age-stratified associations (<50 vs ≥50 years) between circulating 25(OH)D levels and the risk of CRC in a large sample of Korean adults. METHODS: Our cohort study included 236,382 participants (mean age, 38.0 [standard deviation, 9.0] years) who underwent a comprehensive health examination, including measurement of serum 25(OH)D levels. Serum 25(OH)D levels were categorized as <10, 10 to 20, and ≥20 ng/mL. CRC, along with the histologic subtype, site, and invasiveness, was ascertained through linkage with the national cancer registry. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CRC according to the serum 25(OH)D status, with adjustment for potential confounders. RESULTS: During the 1,393,741 person-years of follow-up (median, 6.5 years; interquartile range, 4.5-7.5 years), 341 participants developed CRC (incidence rate, 19.2 per 105 person-years). Among young individuals aged <50 years, serum 25(OH)D levels were inversely associated with the risk of incident CRC with HRs (95% CIs) of 0.61 (0.43-0.86) and 0.41 (0.27-0.63) for 25(OH)D 10 to 19 ng/mL and ≥20 ng/mL, respectively, with respect to the reference (<10 ng/mL) (P for trend <.001, time-dependent model). Significant associations were evident for adenocarcinoma, colon cancer, and invasive cancers. For those aged ≥50 years, associations were similar, although slightly attenuated compared with younger individuals. CONCLUSIONS: Serum 25(OH)D levels may have beneficial associations with the risk of developing CRC for both early-onset and late-onset disease.

Deep learning model using stool pictures for predicting endoscopic mucosal inflammation in patients with ulcerative colitis.

OBJECTIVES: Stool characteristics may change depending on the endoscopic activity of ulcerative colitis (UC). We developed a deep learning model using stool photos of patients with UC (DLSUC) to predict endoscopic mucosal inflammation. METHODS: This was a prospective multicenter study conducted in six tertiary referral hospitals. Patients scheduled to undergo endoscopy for mucosal inflammation monitoring were asked to take photos of their stool using smartphones within 1 week before the day of endoscopy. DLSUC was developed using 2161 stool pictures from 306 patients and tested on 1047 stool images from 126 patients. The ulcerative colitis endoscopic index of severity (UCEIS) was used to define endoscopic activity. The performance of DLSUC in endoscopic activity prediction was compared with that of fecal calprotectin (Fcal). RESULTS: The area under the receiver operating characteristic curve (AUC) of DLSUC for predicting endoscopic activity was 0.801 (95% confidence interval [CI] 0.717-0.873), which was not statistically different from the AUC of Fcal (0.837 [95% CI, 0.767-0.899, DeLong's P=0.458]). When rectal sparing cases (23/126, 18.2%) were excluded, the AUC of DLSUC increased to 0.849 (95% CI, 0.760-0.919). The accuracy, sensitivity, and specificity of DLSUC in predicting endoscopic activity were 0.746, 0.662, and 0.877 in all patients and 0.845, 0.745, and 0.958 in patients without rectal sparing, respectively. Active patients classified by DLSUC were more likely to experience disease relapse during a median 8-month follow-up (log-rank test, P=0.002). CONCLUSIONS: DLSUC demonstrated a good discriminating power similar to that of Fcal in predicting endoscopic activity with improved accuracy in patients without rectal sparing. This study implies that stool photos are a useful monitoring tool for typical UC.

Metabolic-associated fatty liver disease is associated with colorectal adenomas in young and older Korean adults.

BACKGROUND AND AIMS: Given that the majority of colorectal cancers (CRCs) develop from high-risk adenomas, identifying risk factors for high-risk adenomas is important. The relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and the risk of colorectal adenoma in young adults remains unclear. We aimed to evaluate this relationship in adults <50 (younger) and ≥50 (older) years of age. METHODS: This cross-sectional study included 184 792 Korean adults (80% <50 years of age) who all underwent liver ultrasound and colonoscopy. Participants were grouped into those with and without MAFLD and classified by adenoma presence into no adenoma, low-risk adenoma, or high-risk adenoma (defined as ≥3 adenomas, any ≥10 mm, or adenoma with high-grade dysplasia/villous features). RESULTS: The prevalence of low- and high-risk adenomas among young and older adults was 9.6% and 0.8% and 22.3% and 4.8%, respectively. MAFLD was associated with an increased prevalence of low- and high-risk adenomas in young and older adults. Young adults with MAFLD had a 1.30 (95% CIs 1.26-1.35) and 1.40 (1.23-1.59) times higher prevalence of low- and high-risk adenomas, respectively, compared to those without MAFLD. These associations were consistent even in lean adults (BMI < 23 kg/m2 ) and those without a family history of CRC. CONCLUSIONS: MAFLD is associated with an increased prevalence of low- and high-risk adenomas in Korean adults, regardless of age or obesity status. Whether reducing metabolic risk factors, such as MAFLD, reduces the risk of precancerous lesions and ultimately reduces the risk of early-onset CRC requires further investigation.

Enrichment of Activated Fibroblasts as a Potential Biomarker for a Non-Durable Response to Anti-Tumor Necrosis Factor Therapy in Patients with Crohn's Disease.

We investigated whether the response to anti-tumor necrosis factor (anti-TNF) treatment varied according to inflammatory tissue characteristics in Crohn's disease (CD). Bulk RNA sequencing (RNA-seq) data were obtained from inflamed and non-inflamed tissues from 170 patients with CD. The samples were clustered based on gene expression profiles using principal coordinate analysis (PCA). Cellular heterogeneity was inferred using CiberSortx, with bulk RNA-seq data. The PCA results displayed two clusters of CD-inflamed samples: one close to (Inflamed_1) and the other far away (Inflamed_2) from the non-inflamed samples. Inflamed_1 was rich in anti-TNF durable responders (DRs), and Inflamed_2 was enriched in non-durable responders (NDRs). The CiberSortx results showed that the cell fraction of activated fibroblasts was six times higher in Inflamed_2 than in Inflamed_1. Validation with public gene expression datasets (GSE16879) revealed that the activated fibroblasts were enriched in NDRs over Next, we used DRs by 1.9 times pre-treatment and 7.5 times after treatment. Fibroblast activation protein (FAP) was overexpressed in the Inflamed_2 and was also overexpressed in the NDRs in both the RISK and GSE16879 datasets. The activation of fibroblasts may play a role in resistance to anti-TNF therapy. Characterizing fibroblasts in inflamed tissues at diagnosis may help to identify patients who are likely to respond to anti-TNF therapy.

Risk of Metachronous Colorectal Advanced Neoplasia and Cancer in Patients With 3-4 Nonadvanced Adenomas at Index Colonoscopy: A Systematic Review and Meta-Analysis.

INTRODUCTION: This systematic review and meta-analysis evaluated the available evidence on the risk of metachronous advanced neoplasia (AN) and colorectal cancer (CRC) in patients with 3-4 nonadvanced adenomas (NAAs). METHODS: We searched MEDLINE, EMBASE, and Cochrane Library databases up to January 2021 for studies evaluating metachronous AN and CRC risk by comparing 3 groups (1-2 vs 3-4 vs ≥5 NAAs) at index colonoscopy. The estimates for risk of metachronous AN and CRC were evaluated using random-effects models. RESULTS: Fifteen studies (n = 36,375) were included. The risk of metachronous AN was significantly higher in the 3-4 NAAs group than in the 1-2 NAAs group (relative risk [RR] 1.264, 95% confidence interval [CI] 1.053-1.518, P = 0.012; I2 = 0%); there was no difference between the ≥ 5 NAAs and 3-4 NAAs groups (RR 1.962, 95% CI 0.972-3.958, P = 0.060; I2 = 68%). The risks of metachronous CRC between the 1-2 NAAs and 3-4 NAAs groups (RR 2.663, 95% CI 0.391-18.128, P = 0.317; I2 = 0%) or the 3-4 NAAs and ≥ 5 NAAs groups (RR 1.148, 95% CI 0.142-9.290, P = 0.897; I2 = 0%) were not significantly different. DISCUSSION: Although the risk of metachronous AN was greater in the 3-4 NAAs group than in the 1-2 NAAs group, the risk of metachronous AN and CRC between the 3-4 NAAs and ≥ 5 NAAs groups was not different. This suggests that further studies on metachronous AN and CRC risk in the 3-4 NAAs group are warranted to confirm a firm ≥5-year interval surveillance colonoscopy.

Meta-analysis of 16S rRNA microbial data identified alterations of the gut microbiota in COVID-19 patients during the acute and recovery phases.

BACKGROUND: Dozens of studies have demonstrated gut dysbiosis in COVID-19 patients during the acute and recovery phases. However, a consensus on the specific COVID-19 associated bacteria is missing. In this study, we performed a meta-analysis to explore whether robust and reproducible alterations in the gut microbiota of COVID-19 patients exist across different populations. METHODS: A systematic review was conducted for studies published prior to May 2022 in electronic databases. After review, we included 16 studies that comparing the gut microbiota in COVID-19 patients to those of controls. The 16S rRNA sequence data of these studies were then re-analyzed using a standardized workflow and synthesized by meta-analysis. RESULTS: We found that gut bacterial diversity of COVID-19 patients in both the acute and recovery phases was consistently lower than non-COVID-19 individuals. Microbial differential abundance analysis showed depletion of anti-inflammatory butyrate-producing bacteria and enrichment of taxa with pro-inflammatory properties in COVID-19 patients during the acute phase compared to non-COVID-19 individuals. Analysis of microbial communities showed that the gut microbiota of COVID-19 recovered patients were still in unhealthy ecostates. CONCLUSIONS: Our results provided a comprehensive synthesis to better understand gut microbial perturbations associated with COVID-19 and identified underlying biomarkers for microbiome-based diagnostics and therapeutics.

Risk of post-polypectomy bleeding after endoscopic mucosal resection in patients receiving antiplatelet medication: comparison between the continue and hold groups.

BACKGROUND: Current guidelines recommend continuing aspirin and discontinuing clopidogrel for colon polypectomy, but evidence for endoscopic mucosal resection (EMR) is insufficient. We aimed to assess post-polypectomy bleeding (PPB) in patients receiving antiplatelet agents and underwent EMR for various polyp sizes. METHODS: A single-center, prospective observational study was performed. Patients who underwent at least one EMR for polypectomy and those who received aspirin or clopidogrel were included. We compared PPB between the antiplatelet hold group (stopped antiplatelet therapy at least 5 days before the procedure) and continue group (antiplatelet therapy was maintained or stopped within 5 days before the procedure). RESULTS: Among patients who underwent EMR, 305 took aspirin (hold group 257, continue group 48) and 77 took clopidogrel (hold group 66, continue group 11). The mean number of polyps was four, and the mean size was 8.6 mm. There was no difference in the major PPB rate between the hold and continue groups among aspirin users (2.0% vs. 4.2%, P = 0.30), but it was significantly higher in the continue group than in the hold group among clopidogrel users (18.2% vs. 0%, P = 0.02). In patient- and polyp-based logistic regression analysis of clopidogrel users, the number of EMRs (OR 2.12, 95% CI 1.16-3.88), polyp size (OR 1.26, 95% CI 1.06-1.49), and continuing clopidogrel (OR 9.75, 95% CI 1.99-47.64) were independent risk factors for PPB. CONCLUSION: Continuous administration of antiplatelet agents was significantly associated with higher PPB in clopidogrel users, but not in aspirin users. Endoscopists should consider holding clopidogrel if the EMR includes polypectomy.

Impact of the 24-hour time target policy for emergency departments in South Korea: a mixed method study in a single medical center.

BACKGROUND: In South Korea, after the spread of the Middle East Respiratory Syndrome epidemic was aggravated by long stays in crowded emergency departments (EDs), a 24-hour target policy for EDs was introduced to prevent crowding and reduce patients' length of stay (LOS). The policy requires at least 95% of all patients to be admitted, discharged or transferred from an ED within 24 hours of arrival. This study analyzes the effects of the 24-hour target policy on ED LOS and compliance rates and describes the consequences of the policy. METHODS: A mixed-methods approach was applied to a retrospective observational study of ED visits combined with a survey of medical professionals. The primary measure was ED LOS, and the secondary measure was policy compliance rate which refers to the proportion of patient visits with a LOS shorter than 24 hours. Patient flow, quality of care, patient safety, staff workload, and staff satisfaction were also investigated through surveys. Mann-Whitney U and χ2 tests were used to compare variables before and after the introduction of the policy. RESULTS: The median ED LOS increased from 3.9 hours (interquartile range [IQR] = 2.1-7.6) to 4.5 hours (IQR = 2.5-8.5) after the policy was introduced. This was likely influenced by the average monthly number of patients, which greatly increased from 4819 (SD = 340) to 5870 (SD = 462) during the same period. The proportion of patients with ED LOS greater than 24 hours remained below5% only after 6 months of policy implementation, but the number of patients whose disposition was decided at 23 hours increased by 4.84 times. Survey results suggested that patient flow and quality of care improved slightly, while the workload of medical staff worsened. CONCLUSIONS: After implementing the 24-hour target policy, the proportion of patients whose ED LOS exceeded 24 hours decreased, even though the median ED LOS increased. However, the unintended consequences of the policy were observed such as increased medical professional workload and abrupt expulsion of patients before 24 hours.

Impact of Insurance Benefits and Education on Point-of-Care Ultrasound Use in a Single Emergency Department: An Interrupted Time Series Analysis.

Background and Objectives: Point-of-care ultrasound (POCUS) is a useful tool that helps clinicians properly treat patients in emergency department (ED). This study aimed to evaluate the impact of specific interventions on the use of POCUS in the ED. Materials and Methods: This retrospective study used an interrupted time series analysis to assess how interventions changed the use of POCUS in the emergency department of a tertiary medical institute in South Korea from October 2016 to February 2021. We chose two main interventions-expansion of benefit coverage of the National Health Insurance (NHI) for emergency ultrasound (EUS) and annual ultrasound educational workshops. The primary variable was the EUS rate, defined as the number of EUS scans per 1000 eligible patients per month. We compared the level and slope of EUS rates before and after interventions. Results: A total of 5188 scanned records were included. Before interventions, the EUS rate had increased gradually. After interventions, except for the first workshop, the EUS rate immediately increased significantly (p < 0.05). The difference in the EUS rate according to the expansion of the NHI was estimated to be the largest (p < 0.001). However, the change in slope significantly decreased after the third workshop during the coronavirus disease 2019 pandemic (p = 0.004). The EUS rate increased significantly in the presence of physicians participating in intensive POCUS training (p < 0.001). Conclusion: This study found that expansion of insurance coverage for EUS and ultrasound education led to a significant and immediate increase in the use of POCUS, suggesting that POCUS use can be increased by improving education and insurance benefits.

Online Learning versus Hands-On Learning of Basic Ocular Ultrasound Skills: A Randomized Controlled Non-Inferiority Trial.

Background and objectives: Ocular ultrasound is a core application of point-of-care ultrasound (POCUS) to assist physicians in promptly identifying various ocular diseases at the bedside; however, hands-on POCUS training is challenging during a pandemic. Materials and Methods: A randomized controlled non-inferiority trial was conducted in an academic emergency department from October 2020 to April 2021. Thirty-two participants were randomly assigned to one of two groups. Group H (hands-on learning group) participated individually in a hands-on session with a standardized patient for 30 min, whereas Group O (online learning group) learned training materials and video clips for 20 min. They scanned four eyeballs of two standardized patients sequentially following the ocular POCUS scan protocol. Repeated POCUS scans were performed 2 weeks later to assess skill maintenance. Both groups completed the pre- and post-surveys and knowledge tests. Two emergency medicine faculty members blindly evaluated the data and assigned a score of 0−25. The primary endpoint was the initial total score of scan quality evaluated using non-inferiority analysis (generalized estimating equation). The secondary endpoints were total scores for scan quality after 2 weeks, scan time, and knowledge test scores. Results: The least squares means of the total scores were 21.7 (0.35) for Group O and 21.3 (0.25) for Group H, and the lower bound of the 95% confidence interval (CI) was greater than the non-inferiority margin of minus 2 (95% CI: −0.48−1.17). The second scan scores were not significantly different from those of the first scan. The groups did not differ in scanning time or knowledge test results; however, Group H showed higher subjective satisfaction with the training method (p < 0.001). Conclusion: This study showed that basic online ocular ultrasound education was not inferior to hands-on education, suggesting that it could be a useful educational approach in the pandemic era.

Detection of SARS-CoV-2 in Fecal Samples From Patients With Asymptomatic and Mild COVID-19 in Korea.

BACKGROUND & AIMS: Although coronavirus disease 2019 (COVID-19) is characterized by fever and respiratory symptoms, some patients have no or mild symptoms. Severe acute respiratory syndrome-coronavirus (SARS-CoV-2) has been detected in feces of patients. We investigated gastrointestinal symptoms and shedding of virus into feces of patients with asymptomatic or mild COVID-19. METHODS: We collected data from 46 patients (median age, 26 y; 46% men) with asymptomatic or mild COVID-19 (without fever and pneumonia) and prolonged respiratory shedding of SARS-CoV-2, quarantined from April 4, 2020, through April 24, 2020, in Korea. Respiratory specimens included upper respiratory specimens (nasopharyngeal and oropharyngeal swabs) and lower respiratory specimens (sputum), and were collected twice per week. The median interval between COVID-19 diagnosis to the start of fecal sample collection was 37 days (range, 29-41 d); 213 stool specimens were collected from 46 patients. We used real-time reverse-transcription polymerase chain reaction to detect SARS-CoV-2 in the respiratory and fecal specimens. RESULTS: Gastrointestinal manifestations were observed in 16 of the 46 patients (35%); diarrhea was the most common (15%), followed by abdominal pain (11%), dyspepsia (11%), and nausea (2%). Virus RNA was detected in feces from 2 patients without gastrointestinal symptoms (4%). Mean cycle threshold values from the time of quarantine to the time of fecal collection tended to be lower in patients with virus detected in fecal samples than in patients without virus in fecal samples (29.91 vs 33.67 in the first week, 29.47 vs 35.71 in the fifth week, respectively). Shedding of virus into feces persisted until day 50 after diagnosis; fecal samples began to test negative before or at approximately the time that respiratory specimens also began to test negative. CONCLUSIONS: In an analysis of fecal and respiratory specimens from patients with COVID-19 in quarantine in Korea, we found that the gastrointestinal tract could be a route of transmission of SARS-CoV-2 even in patients with asymptomatic or mild disease, with no gastrointestinal symptoms. The viral load of the respiratory specimens appears be related to shedding of the virus into feces in this group of patients.

Do epoch lengths of hypnotic depth indicators affect estimated of blood-brain equilibration rate constants of propofol?

This study aimed to investigate the effect of epoch length of hypnotic depth indicators on the blood-brain equilibration rate constant (ke0) estimates of propofol. Propofol was administered by zero-order infusion (1.5, 3.0, 6, and 12 mg·kg-1·h-1) for one hour in 63 healthy volunteers. The ke0 of propofol was estimated using an effect-compartment model linking pharmacokinetics and pharmacodynamics, in which response variables were electroencephalographic approximate entropy (ApEn) or bispectral index (BIS) (n = 32 each for propofol infusion rates of 6 and 12 mg·kg-1·h-1). Epoch lengths of ApEn were 2, 10, 30, and 60 seconds (s). The correlations between plasma propofol concentrations (Cp) and BIS and ApEn 2, 10, 30, and 60 s were determined, as was the Ce associated with 50% probability of unconsciousness (Ce50,LOC). The pharmacokinetics of propofol were well described by a three-compartment model. The correlation coefficient between Cp and ApEn 2, 10, 30, and 60 s were -0.64, -0.54, -0.39, and -0.26, respectively, whereas correlation coefficient between Cp and BIS was -0.74. The blood-brain equilibration half-life based on the ke0 estimates for ApEn at 2, 10, 30, 60 s and BIS were 4.31, 3.96, 5.78. 6.54, 5.09 min, respectively, whereas the Ce50,LOC for ApEn at 2, 10, 30, 60 s and BIS were 1.55, 1.47, 1.28, 1.04, and 1.55 µg·ml-1, respectively. Since ke0, which determines the onset of drug action, varies according to the epoch length, it is necessary to consider the epoch length together when estimating ke0.

Skeletal muscle mass and risk of advanced adenoma in surveillance colonoscopy.

BACKGROUND AND AIM: Sarcopenia has been suggested to be associated with chronic inflammation and insulin resistance. This study aimed to evaluate whether low muscle mass is associated with the incidence and recurrence of advanced colorectal adenoma. METHODS: We conducted a cohort study including 14 701 participants who underwent first-time screening colonoscopy between 2003 and 2012 and follow-up colonoscopy until 2017. Skeletal muscle mass was measured using a bioelectrical impedance analyzer and divided by body weight to calculate the skeletal muscle mass index (SMI). RESULTS: During a median 47 (interquartile range, 35-58) months of follow-up, overall and advanced adenoma developed in 2988 (20.3%) and 207 (1.41%) participants, respectively. In multivariate analysis using models adjusted for baseline adenoma risk, lifestyle factors, markers for insulin resistance and chronic inflammation, and metabolic syndrome, decreasing SMI quartiles were associated with increased risk of occurrence of advanced adenoma and overall adenoma. The adjusted hazard ratios (95% confidence intervals) comparing SMI quartiles 3, 2, and 1 to quartile 4 were 1.57 (1.03-2.41), 1.22 (0.78-1.92), and 1.77 (1.13-2.76), respectively, for advanced adenoma (P for trend = 0.049) and 1.05 (0.95-1.17), 1.09 (0.98-1.21), and 1.26 (1.13-1.41), respectively, for overall adenoma (P for trend < 0.001). CONCLUSIONS: In this large cohort with long-term colonoscopy follow-up, low relative muscle mass was associated with increased risk of occurrence of advanced adenoma and overall adenoma at follow-up colonoscopy, independent of metabolic and inflammatory markers. Timely and thorough surveillance colonoscopy may be emphasized in such populations.

Simple proxies for detection of clinically significant serrated polyps and data for their benchmarks.

BACKGROUND AND AIMS: Serrated polyp detection rate (SDR) is a potential quality indicator for preventing colorectal cancer associated with the serrated pathway. Using clinically significant SDR (CSSDR) has been suggested based on clinically significant serrated polyp's ability to be colorectal cancer precursors. Correlations between CSSDR and simpler SDRs, other than proximal SDR, have not yet been studied. We aimed to investigate which simpler SDR indicator is most relevant to CSSDR or adenoma detection rate (ADR) and provide benchmark data. METHODS: We analyzed 26 627 colonoscopies performed by 30 endoscopists. Clinically significant serrated polyps were defined as any sessile serrated adenoma/polyp or traditional serrated adenoma, hyperplastic polyps ≥ 5 mm in the proximal colon, or hyperplastic polyps ≥ 10 mm anywhere in the colon. Correlation of CSSDR and ADR with other simple SDRs, SDR-pathology (sessile serrated adenoma/polyp or traditional serrated adenoma), SDR-size (≥ 10 mm), and SDR-location (proximal location) was analyzed using Pearson's correlation test and Steiger's z-test. RESULTS: The CSSDR was 1.7% to 13.2% (mean = 6.1%). The correlation coefficient of CSSDR/SDR-size was 0.91 (P < 0.01), which was higher than that of CSSDR/SDR-location (0.64, P < 0.01) (0.91 vs 0.61, P < 0.01). The correlation coefficient of ADR/CSSDR and ADR/SDR-location was 0.41 (P < 0.01) and 0.81 (P < 0.01), respectively. For ADR ≥ 25%, endoscopists' median screening CSSDR was 5.4%, while SDR-location and SDR-size were 10.9% and 2.2%, respectively. CONCLUSION: Large SDR could be a simple proxy for CSSDR, in addition to proximal SDR. Large SDR and proximal SDR benchmarks of 2.2% and 10.9% may guide adequate serrated polyp detection with uniform definitions and simpler calculations.

Association between waist circumference and risk of colorectal neoplasia in normal-weight adults.

BACKGROUND AND AIM: Abdominal obesity, measured using waist circumference (WC), is associated with the colorectal neoplasia (CRN) risk. We examined whether WC is associated with the CRN risk even in normal-weight individuals. METHODS: A cross-sectional study was performed on asymptomatic normal-weight (body mass index 18.5-23 kg/m2 ) individuals who underwent colonoscopy as health checkups. RESULTS: Of 63 057 examinees, 30 498 were men (mean age, 41.1 years) and 32 559 were women (mean age, 41.7 years). The prevalence of overall CRN in WC quartiles 1, 2, 3, and 4 was 14.2%, 15.5%, 15.5%, and 18.7%, respectively, in men and 7.4%, 8.9%, 9.4%, and 11.5%, respectively, in women. The prevalence of advanced CRN (ACRN) in WC quartiles 1, 2, 3, and 4 was 1.5%, 1.3%, 1.6%, and 2.1%, respectively, in men and 1.0%, 1.3%, 1.2%, and 1.3%, respectively, in women. Among men, the overall CRN risk in quartile 4 (> 82 cm) was higher than that in quartiles 1, 2, and 3 (adjusted odds ratio, OR [95% confidence interval, CI], 1.22 [1.11-1.34], 1.12 [1.05-1.23], and 1.18 [1.07-1.29], respectively); the ACRN risk in quartile 4 was also higher than that in quartiles 1, 2, and 3 (adjusted OR [95% CI], 1.41 [1.09-1.81], 1.56 [1.19-2.03], and 1.50 [1.16-1.94], respectively). Among women, the overall CRN risk in quartile 4 (> 77 cm) was higher than that in quartiles 1 and 3; the ACRN risk was not different among all groups. CONCLUSIONS: Even with a normal weight, a large WC was associated with the CRN risk, especially with the ACRN risk in men.

Novel sulfate tablet PBK-1701TC versus oral sulfate solution for colon cleansing: A randomized phase 3 trial.

BACKGROUND AND AIM: PBK-1701TC is a novel sulfate tablet-based that contains 320 mg of simethicone and delivers 90% of the salt and water delivered by oral sulfate solution (OSS) preparation. This study evaluated the efficacy, safety, and tolerability of PBK-1701TC compared with OSS in bowel preparation for colonoscopy. METHODS: This randomized, multicenter, phase 3 non-inferiority trial included adults aged 19 years or older with a body mass index of 19-30 kg/m2 undergoing colonoscopy at five university hospitals in Korea. The primary efficacy endpoint was successful bowel-cleansing rate, defined as Harefield Cleansing Scale grade A or B as evaluated by blinded central readers. Secondary endpoints included the presence of residual air bubbles. Adverse events and laboratory evaluations were monitored to assess safety. Tolerability was assessed via participant interview. RESULTS: Overall, 235 participants were randomized, and 224 were included in the per-protocol analysis (PBK, 112; OSS, 112). Successful bowel cleansing was achieved for 95.5% (107/112) in the PBK group, which was non-inferior to the OSS group (98.2%, 110/112) with a difference of -2.7% (one sided 97.5% confidence limit, -8.1%). The participants in the PBK group had fewer intraluminal bubbles (0.9% vs 81.3%, P < 0.001) and reported a lower incidence of nausea and vomiting, with better acceptance, taste, and willingness to repeat the regimen than those in the OSS group (all P < 0.05). CONCLUSION: The novel sulfate tablet, PBK-1701TC, was non-inferior to OSS with respect to bowel-cleansing efficacy and exhibited better safety and tolerability in adults undergoing colonoscopy.

Prevalence of and Risk Factors for Colorectal Neoplasia in Asymptomatic Young Adults (20-39 Years Old).

BACKGROUND & AIMS: The incidence of colorectal cancer is increasing among persons 50 years old or younger. However, data on the epidemiology of young-onset colorectal neoplasia (CRN) are limited. Although some studies have investigated the epidemiology of CRN in persons younger than 50 years, most have focused on persons 40 years or older. We evaluated the prevalence of and risk factors for CRN in adults younger than 40 years. METHODS: We performed a cross-sectional analysis of 72,356 asymptomatic individuals, 20-39 years old, who underwent colonoscopies as participants in the Kangbuk Samsung Health Study in South Korea, from August 2004 through December 2015. Data on medical history and health-related behavior were collected from self-administered questionnaires. Patients were divided into groups based on age (20-29 years, n = 7340 or 30-39 years, n = 65,016), and χ2 tests were used to compare categorical variables between groups. A multivariate logistic regression model was used to assess the risk factors for overall and advanced CRN. RESULTS: The prevalence of overall CRN in group of 20-29 years was 5.9% and in the group of 30-39 years was 9.5% (P < .001); prevalence values for advanced CRN were 0.6% and 0.9%, respectively (P = .005). In the group of 30-39 years, age, smoking, alcohol intake, obesity, and abdominal obesity were independent risk factors for overall and advanced CRN. Additionally, male sex and metabolic syndrome were independent risk factors for overall CRN, whereas regular exercise reduced risk of overall CRN. Even in the 20-29 years group, obesity, abdominal obesity, and increased levels of triglycerides were independent risk factors for overall and advanced CRN, whereas age, increased blood pressure, and increased fasting blood glucose level were independent risk factors for overall CRN. CONCLUSION: In a retrospective analysis of 72,356 asymptomatic persons under 40 years of age evaluated by colonoscopy in Korea, we found modifiable factors, such as smoking, alcohol intake, obesity, and metabolic syndrome, to be significant risk factors for CRN-even in persons of 20-39 years old. Colorectal cancer screening strategies should consider these risk factors.

Association Between Cotinine-verified Smoking Status and Risk of Colorectal Neoplasia.

GOALS: We evaluated the association of urinary cotinine-verified smoking status with the risk of colorectal neoplasia (CRN). BACKGROUND: Many studies have reported the association between the risk of CRN and smoking status, based on self-reported questionnaires. Although self-reported smoking status may be inaccurate, to our knowledge, no study has yet assessed the association between objective biomarkers of tobacco exposure and the risk of CRN. STUDY: A cross-sectional study was conducted on 96,806 asymptomatic examinees who underwent colonoscopy and urinary cotinine measurements as part of a health check-up. Cotinine-verified current smokers were participants having a urinary cotinine level ≥50 ng/mL. RESULTS: The mean participant age was 38.4 years, and the proportion of cotinine-verified current smokers was 23.0%. Cotinine-verified current smoking was an independent risk factor for CRN [adjusted odds ratio (AOR), 1.49; 95% confidence interval (CI), 1.42-1.56] and advanced CRN (ACRN) (AOR, 1.79; 95% CI, 1.57-2.05). Moreover, the risk of CRN and ACRN increased with increasing cotinine levels. Among self-reported never smokers, cotinine-verified current smokers had a higher risk of CRN (AOR, 1.77; 95% CI, 1.57-2.00) and ACRN (AOR, 1.94; 95% CI, 1.37-2.74) than cotinine-verified never smokers did, whereas among self-reported current smokers, cotinine-verified never smokers had a lower risk of CRN (AOR, 0.78; 95% CI, 0.70-0.87) and ACRN (AOR, 0.71; 95% CI, 0.52-0.98) than cotinine-verified current smokers did. CONCLUSIONS: Cotinine-captured smoking status and metabolic variation exhibit associations with CRN more accurately and objectively than self-reporting does, providing clearer evidence for the role of tobacco in the development of CRN.

A Randomized Controlled Trial Comparing Colonoscopic Enema With Additional Oral Preparation as a Salvage for Inadequate Bowel Cleansing Before Colonoscopy.

GOALS: The goal of this study was to evaluate the noninferiority of colonoscopic enema to additional oral preparation in salvage bowel cleansing for inadequate preparation for a morning colonoscopy. BACKGROUND: Colonoscopic enema, administering additional cathartics into the right colon through the colonoscope accessory channel, is suggested to rescue poor bowel preparation for a colonoscopy but lacking comparative study. STUDY: In this prospective, randomized, actively-controlled, parallel group, noninferiority trial, consecutive outpatients and health checkup recipients aged from 19 to 70 years with inappropriate bowel preparation during an elective colonoscopy were enrolled to receive either a colonoscopic enema of 1 L polyethylene glycol (PEG) (enema group) or additional oral intake of 2 L PEG (oral group). The primary endpoint was the proportion of adequate bowel preparation evaluated using the Boston Bowel Preparation Scale. RESULTS: Overall, 131 participants were randomized. Adequate bowel preparation was achieved in 53% (35/66) of the enema group, which was significantly inferior to the oral group (81.5%; 53/67) with a difference of -28.5% (95% confidence interval, -44.1, -12.9; P=0.001). The largest difference in the proportion of adequate bowel preparation was observed in the right colon (57.8% in the enema group vs. 86.9% in the oral group; P<0.001), followed by the transverse colon (85.9% vs. 98.4%; P=0.017) and the left colon (90.6% vs. 96.7%; P=0.274). CONCLUSIONS: The colonoscopic enema of 1 L PEG was inferior to the additional oral ingestion of 2 L PEG regarding efficacy as a salvage bowel preparation in adults with inadequate bowel cleansing for colonoscopy.