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Low-dose aspirin and metformin have been individually associated with a reduced risk of cancer. Whether their concurrent use in adults with type 2 diabetes mellitus (T2DM) is associated with a reduced risk of colorectal cancer (CRC) is unclear.Among individuals with T2DM taking metformin, we sought to evaluate the association between low-dose aspirin versus no aspirin and the risk of CRC.A multiple-database new-user cohort study of patients with T2DM taking metformin was conducted between 2007-2010 (Clinical Data Analysis and Reporting System [CDARS], Hong Kong) and 2007-2016 (The Health Improvement Network [THIN], UK). The primary outcome was incident CRC. Patients were followed from index date of prescription until the earliest occurrence of an outcome of interest, an incident diagnosis of any cancer, death, or until December 31, 2019. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI). Estimates were pooled using an inverse variance random effects model, and heterogeneity was assessed using IAfter one-to-one propensity-score matching, 57,534 patients were included (CDARS = 16,276; THIN = 41,258). The median (IQR) follow-up was 9.3 (6.5-10.7) years in CDARS and 3.2 (1.1-5.8) years in THIN. The concurrent use of low-dose aspirin and metformin was not associated with a lower risk of CRC compared to metformin only (HR = 0.89, 95% CI 0.75-1.05, ILow-dose aspirin was not associated with a lower risk of CRC in patients with T2DM taking metformin. Our study does not support the routine use of low-dose aspirin in this population. This article is protected by copyright. All rights reserved.

Efficacy with conventional intra muscular (IM) hepatitis B vaccination in patients with inflammatory bowel disease (IBD) is suboptimal.To compare the immunogenicity of intradermal (ID) hepatitis B vaccination after topical imiquimod pre-treatment with IM hepatitis B vaccination in patients with IBD.Adult IBD patients with no evidence of hepatitis B infection or immunity (negative to HBsAg/anti-HBc/anti-HBs) were randomised 1:1 to receive either ID hepatitis B vaccine with topical imiquimod pre-treatment to injection site (ID-Imq) or IM hepatitis B vaccine with aqueous cream pre-treatment (IM-Aq) at 0, 1 and 6 months. Patients and investigators were blinded to the randomisation and intervention. The primary endpoint was seroprotection rate at 12-month, defined as percentage of subjects with anti-HBs ≥10 mIU/ml.Between September 2019 and December 2020, 104 patients with IBD (68% male; 50% Crohn's) enrolled, and 53 assigned to ID-Imq group. The percentage of patients using steroids, immunomodulators or biologics at randomisation was 15%, 55% or 22%, respectively. Seroprotection rate at 12 months was significantly higher in the ID-Imq group than the IM-Aq group (91% vs 69%; OR 4.39, 95% CI 1.47-13.11). Multivariate analysis showed that ID vaccine with topical imiquimod and higher albumin level were associated with a higher seroprotection rate. The safety profile was similar but local reactions were more common in the ID-Imq group.Intradermal hepatitis B vaccination with topical imiquimod pre-treatment is safe and offers superior seroprotection to conventional IM administration in patients with IBD.

Although Helicobacter pylori infection is the most important causative factor for gastric cancer (GC), H. pylori eradication alone does not completely eliminate the GC risk. In addition to H. pylori eradication, other risk factors for GC should be identified and targeted. Diabetes mellitus (DM) confers a 20% increased risk of GC, which could be mediated via several biological mechanisms including the stimulation of cell proliferation via hyperinsulinemia and increased insulingrowth factor production, the promotion of angiogenesis, and DNA damage. With a current global prevalence of 9.3% and a predicted rise to 10.2% by 2030, DM could contribute substantially to the burden of GC cases worldwide. Emerging evidence showed that metformin possesses chemopreventive effects via both direct (e.g., adenosine monophosphate-activated protein kinase activation and subsequent inhibition of the mammalian target of rapamycin pathway) and indirect (e.g., modulation of the interaction between tumor cells and their microenvironment and gut microbiota) pathways. A recent meta-analysis of observational studies showed that metformin use was associated with 24% lower GC risk. However, many available observational studies related to metformin effects suffered from biases including the failure to adjust for the H. pylori infection status and serial glycemic control and time-related biases. Future prospective studies addressing these pitfalls are needed.

Introduction This study was conducted to investigate and compare esthetic perceptions of different facial profiles among Hong Kong Chinese laypersons and patients scheduled for orthognathic treatment. Methods Two sets of 3-dimensional facial photographs (1 male and 1 female) each comprised 7 images that showed different dentoskeletal relations (ie, Class I, bimaxillary protrusion, bimaxillary retrusion, maxillary protrusion, maxillary retrusion, mandibular protrusion, and mandibular retrusion). The sets of photographs were shown to 101 laypersons (age, 28.87 ± 6.22 years) and 60 patients seeking orthognathic treatment (age, 27.12 ± 6.07 years). They rated their esthetic perceptions of the photographs on the basis of a 100 mm visual analog scale (VAS) from 0 (very unattractive) to 100 (very attractive). Results The dentoskeletal Class I facial profile was ranked as the most attractive profile. Female orthognathic judges selected the retrusive maxilla while male orthognathic judges and male and female laypersons ranked the mandibular protrusion profile as the least attractive profile for both females and males. A bimaxillary protrusive female profile was viewed as more attractive by the orthognathic male (P = 0.006) and female (P = 0.006) judges, compared with female layperson judges. After adjustment for age, no statistically significant interaction between sex and judges (P >0.10) for all VAS scores were detected. For the female bimaxillary protrusive profile, orthognathic patient judges assigned a mean VAS score of 9.174 points higher than layperson judges (95% confidence interval, 3.11-15.24; P = 0.003). Conclusion Dentoskeletal Class I facial profile was generally considered the most attractive profile in both sexes; male and female orthognathic patients preferred a bimaxillary protrusive female profile. A concave facial profile was perceived as least attractive in both sexes.

Background The long-term effects of H. pylori eradication in preventing upper GI bleeding (UGIB) remains unknown. Aim To determine the long-term risks of UGIB after H. pylori eradication METHODS: We included all patients who had received clarithromycin-containing triple therapy for the treatment of H. pyliori infection between 2003 and 2012, without subsequent need for re-treatment. We included a propensity score (PS)-matched endoscopy cohort of H. pylori-negative patients as controls. The primary endpoint was the risk of subsequent UGIB. A multivariable Cox model was used to compute the hazard ratio (HR) of UGIB. Results We included 62 738 H. pylori-eradicated and 62 738 PS-matched H. pylori-negative patients, with a median follow-up of 8.1 years (IQR 5.5-10.6). The incidence of UGIB was 20.8 (95% CI 19.5-22.1) and 13.6 (95% CI 12.7-14.7) per 10 000 person-years in H. pylori-eradicated and H. pylori-negative patients, respectively. Compared to controls, H. pylori-eradicated patients had a significantly higher risk of UGIB (HR: 1.65, 95% CI 1.49-1.83). The risk of UGIB in H. pylori-eradicated patients increased after the first 2 years of follow up (HR: 2.18, 95% CI 1.91-2.49). Age-stratified analysis showed that patients >45 years had higher UGIB risk, even after eradication. Conclusions Despite H. pylori eradication, the long-term risk of UGIB was still higher than in H. pylori-negative control subjects. The protective effects of eradication therapy in preventing UGIB appeared to be limited to younger patients, and to within the first 2 years after eradication.

Although antithrombotic agents could increase the risk of postpolypectomy bleeding, interruption of these agents also increases the risk of thromboembolism (TE). We assessed the risks of postcolonoscopy TE events and their association with the interruption of antithrombotic agents.This was a retrospective cohort study including consecutive patients undergoing colonoscopy between January 2016 and March 2021. We determined the rates of postcolonoscopy TE events in patients taking various antithrombotic agents (with or without interruption), and in different patient groups according to indications for colonoscopy, underlying TE, and bleeding risks.Of the 6220 patients, 1755 (28.2%) were on antithrombotics. Overall, 20 patients (0.32%) developed TE events, and 25 (0.80%) of 3134 patients with polypectomy experienced major episodes of bleeding. Among all patients on antithrombotic agents, the highest rates of TE events were observed in patients on dual-antiplatelet therapy (4.65%; adjusted odds ratio [aOR], 28.0; 95% CI, 3.77-142.1) and clopidogrel (2.78%; aOR, 12.2; 95% CI, 2.10-57.0), compared with 0.11% among those not on antithrombotics. In patients interrupting anti-thrombotic agents, the risk of TE was increased compared to those on no agent as follows: stopping 2 or more antithrombotic agents (4.55%; aOR, 22.5; 95% CI, 1.09-158.0), monotherapy with clopidogrel (3.06%; aOR, 15.5; 95% CI, 2.86-69.6), warfarin (1.33%; aOR, 6.96; 95% CI, 1.14-33.5), or direct-acting oral anticoagulants (0.87%; aOR, 6.23; 95% CI, 1.22-26.8). Having an underlying high TE risk (aOR, 16.8; 95% CI, 6.33-46.6) was associated with higher postcolonoscopy TE events.The risk of post-colonoscopy thromboembolic events is low. However, the temporary interruption of antithrombotic agents, particularly stopping 2 or more agents, clopidogrel, warfarin, or direct-acting oral anticoagulants was associated with higher postcolonoscopy TE events, particularly in high-risk patients.

BACKGROUND: Previous studies have demonstrated the seasonal variations of non-variceal upper gastrointestinal bleeding (UGIB), but there is scanty data on lower gastrointestinal bleeding (LGIB) and the association with other meteorological parameters.METHODS: We included all patients hospitalized for UGIB and LGIB between 2009 and 2018 in Hong Kong. The monthly age-standardized and sex-standardized GIB incidences were fitted to meteorological data including average temperature (AT), maximum temperature (MaxT), minimum temperature (MinT), temperature range (TR), average precipitation, average atmospheric pressure (AtomP), and average relative humidity after adjusting for prescriptions of aspirin, proton pump inhibitors, and Helicobacter pylori eradication therapy using the autoregressive integrated moving average model.RESULTS: Despite a gradual decline in UGIB incidences, the incidences of UGIB were still higher in winter months. The incidence and fluctuation of both UGIB and LGIB were higher in the older age groups, especially those ≥80 years. The seasonality was only identified in those ≥60 years for UGIB, and only in those ≥80 years for LGIB. UGIB incidence was inversely associated with AT, MaxT, and MinT, but positively associated with TR and AtomP. LGIB was also significantly associated with AT, MaxT, MinT, and AtomP.CONCLUSION: Despite the changes in GIB incidences, the seasonal patterns of GIB were still marked in the elderly. With the aging population, the impacts of seasonal variations on GIB incidences could be considerable.

Background With the increasing use of medications that alter the risk of gastrointestinal bleeding (GIB), comprising aspirin, proton pump inhibitors (PPIs), and Helicobacter pylori eradication therapies, the trends of GIB are evolving. Objective The aim of this study is to determine and predict the trends of GIB and to evaluate the effects of population prescriptions of these medications on GIB incidences. Methods We retrieved patients hospitalized for GIB in all public hospitals in Hong Kong between 2009 and 2019. Monthly age- and sex-standardized GIB data were fitted and predicted, based on population prescriptions of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), anticoagulants, other antiplatelet drugs, PPIs, and H. pylori therapies, using autoregressive integrated moving average model for time series analysis. Results The incidence of upper GIB (UGIB) showed a clear declining trend while lower GIB (LGIB) decreased slightly. Older population (>80 years) had the greatest decline in UGIB but was associated with an increase in LGIB. Prescriptions of PPIs and aspirin increased significantly with time. PPIs prescriptions were negatively associated with UGIB incidence (coefficient log(PPIs) -4.58; 95% confidence interval [CI]: -5.69, -3.47). H. pylori eradication in the previous month showed a nonsignificant trend on UGIB (coefficient -0.14; 95% CI: -0.30, 0.02). In contrast, aspirin increased the incidences of UGIB (coefficient 0.06; 95% CI: 0.04, 0.07) and LGIB (coefficient 0.04; 95% CI: 0.03, 0.05). NSAIDs, anticoagulants, and other antiplatelet drugs were not significantly associated with the trend of either UGIB or LGIB. UGIB is predicted to decline continuously but LGIB is projected to rise, particularly with increasing use of aspirin. Conclusions UGIB incidences were decreasing and had been surpassed by LGIB. Based on population prescriptions of aspirin and PPIs, divergent trends of upper and lower GIB are expected, especially in elderly.

Background: Growth and development in dental education globally depend on effective experience sharing and advocation of evidence-based practice, preferably tested via vigorous peer evaluation. Objective: This study aimed to evaluate the most cited dental education publications. The objectives were to identify the most productive entities, and the most frequently investigated themes and specialties. Methods: A keyword literature search was performed on 1st June 2020 to identify publications relevant to dental education. PubMed, Scopus, Web of Science, ProQuest, and Campbell Collaboration databases were searched. Publications that dealt with dental education were included. Irrelevant publications were manually excluded by the authors, and disagreement was resolved by the senior author. Bibliographic data of the top 102 entries (some with equal citation ranks) were obtained from Scopus and analyzed using Bibliometrix and VOSviewer for characterization of recurring contributors and themes. Results: The top publications included 83 original articles, 15 reviews, 3 books, and 1 online document, written by 30 different authors, with 38 publications from dental journals not dedicated to education, and with an average of 5.5 citations per year. The most productive author was William Hendrickson. The most productive institutions were from Europe and the United States. There were 11 papers focused on operative dentistry, 9 on endodontology, 4 on special care dentistry, 2 on community dentistry, 2 on periodontology, and 2 on implantology. Within the top 102 list, 21 publications focused on the stress experienced by dental students at school. A multiple ANCOVA indicates that citation counts in these highly cited publications are associated with a number of authors and document types, such as “reviews/books/online document” compared with original articles (p Conclusion: Influential dental education studies were published on a variety of platforms. Over the past 20 years, the field witnessed the emergence of highly cited reports/articles. Similar to influential papers in various fields, the number of authors per top-cited dental education publications appeared to be associated with high citations indicating top quality and high appreciation/acceptance of the articles involved.

Background: Gut microbiota can be associated with COVID-19 vaccine immunogenicity. We investigated whether recent antibiotic use influences BNT162b2 vaccine immunogenicity. Methods: BNT162b2 recipients from three centers were prospectively recruited. Outcomes of interest were seroconversion of neutralising antibody (NAb) at day 21, 56 and 180 after first dose. We calculated the adjusted odds ratio (aOR) of seroconversion with antibiotic usage (defined as ever use of any antibiotics within six months before first dose of vaccine) by adjusting for covariates including age, sex, smoking, alcohol, and comorbidities. Results: Of 316 BNT162b2 recipients (100 [31.6%] male; median age: 50.1 [IQR: 40.0–57.0] years) recruited, 29 (9.2%) were antibiotic users. There was a trend of lower seroconversion rates in antibiotic users than non-users at day 21 (82.8% vs. 91.3%; p = 0.14) and day 56 (96.6% vs. 99.3%; p = 0.15), but not at day 180 (93.3% vs. 94.1%). A multivariate analysis showed that recent antibiotic usage was associated with a lower seroconversion rate at day 21 (aOR 0.26;95% CI: 0.08–0.96). Other factors associated with a lower seroconversion rate after first dose of the BNT162b2 vaccine included age ≥ 60 years (aOR: 0.34;95% CI: 0.13–0.95) and male sex (aOR: 0.14, 95% CI: 0.05–0.34). There were no significant factors associated with seroconversion after two doses of BNT16b2, including antibiotic use (aOR: 0.03;95% CI: 0.001–1.15). Conclusions: Recent antibiotic use may be associated with a lower seroconversion rate at day 21 (but not day 56 or 180) among BNT162b2 recipients. Further long-term follow-up data with a larger sample size is needed to reach a definite conclusion on how antibiotics influence immunogenicity and the durability of the vaccine response.

Computer-assisted detection (CADe) is a promising technologic advance that enhances adenoma detection during colonoscopy. However, the role of CADe in reducing missed colonic lesions is uncertain. The aim of this study was to determine the miss rates of proximal colonic lesions by CADe and conventional colonoscopy.This was a prospective, multicenter, randomized, tandem-colonoscopy study conducted in 3 Asian centers. Patients were randomized to receive CADe or conventional white-light colonoscopy during the first withdrawal of the proximal colon (cecum to splenic flexure), immediately followed by tandem examination of the proximal colon with white light in both groups. The primary outcome was adenoma/polyp miss rate, which was defined as any adenoma/polyp detected during the second examination.Of 223 patients (48.6% men; median age, 63 years) enrolled, 7 patients did not have tandem examination, leaving 108 patients in each group. There was no difference in the miss rate for proximal adenomas (CADe vs conventional: 20.0% vs 14.0%, P = .07) and polyps (26.7% vs 19.6%, P = .06). The CADe group, however, had significantly higher proximal polyp (58.0% vs 46.7%, P = .03) and adenoma (44.7% vs 34.6%, P = .04) detection rates than the conventional group. The mean number of proximal polyps and adenomas detected per patient during the first examination was also significantly higher in the CADe group (polyp: 1.20 vs .86, P = .03; adenoma, .91 vs .61, P = .03). Subgroup analysis showed that CADe enhanced proximal adenoma detection in patients with fair bowel preparation, shorter withdrawal time, and endoscopists with lower adenoma detection rate.This multicenter trial from Asia confirmed that CADe can further enhance proximal adenoma and polyp detection but may not be able to reduce the number of missed proximal colonic lesions. (Clinical trial registration number: NCT04294355.).

Biliary tract cancers (BTCs), encompassing cholangiocarcinoma (CCA), gallbladder (GBC), and ampulla of Vater cancers (AVC), are common hepatobiliary cancer after hepatocellular carcinoma with a high mortality rate. As there is no effective chemopreventive agent to prevent BTCs, this study aimed to explore the role of statins on the risk of BTCs.PubMed, Embase, and Cochrane Library from inception until 24 April 2020 were searched according to the Meta-Analyses of Observational Studies in Epidemiology (MOOSE) guidelines. The adjusted risk ratios (aRRs) of BTCs and individual cancer were pooled using a random-effects model.Eight observational studies (3 cohort and 5 case-control studies) were included with 10,485,231 patients. The median age was 68.0 years (IQR: 67.0-71.5) and 48.3% were male. Statins were associated with a lower risk of all BTCs (aRR: 0.67; 95% CI: 0.51-0.87). The pooled aRR for CCA was 0.60 (95% CI: 0.38-0.94) and GBC was 0.78 (95% CI: 0.68-0.90). There was only one study on AVC with aRR of 0.96 (95% CI: 0.66-1.41). The pooled aRR for lipophilic and hydrophilic statins was 0.78 (95% CI: 0.69-0.88) and 0.70 (95% CI: 0.61-0.80), respectively. The effects were attenuated in studies that adjusted for aspirin and/or non-steroidal anti-inflammatory drugs (aRR: 0.80, 95% CI: 0.72-0.89) and metformin (aRR: 0.80, 95% CI: 0.72-0.90).Statins, both lipophilic and hydrophobic, were associated with a lower risk of BTCs, particularly CCA and GBC.

BACKGROUND Despite Helicobacter pylori (HP) eradication, individuals can still develop gastric cancer (GC). Prior studies have demonstrated that nonaspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs) reduce the risk of GC, but this may be caused by immortal time bias and failure to adjust for HP status. The objective of this study was to investigate whether NA-NSAIDs reduced the risk of GC in patients who undergo H. pylori eradication. METHODS Adult patients who had received clarithromycin-based triple therapy between 2003 and 2016 were identified from a territory-wide health care database. Exclusion criteria included prior GC or GC diagnosed

Prior studies showed that calcium channel blockers (CCBs) could modify cancer risk, but data on gastric cancer (GC) are limited. We aimed to investigate whether CCBs could modify GC risk in Helicobacter pylori-eradicated patients. H pylori-infected patients with hypertension who are aged ≥50 and had received clarithromycin-based triple therapy between 2003 and 2016 were identified from a territory-wide healthcare database. Patients with eradication failure, GC diagnosed within 6 months after HP eradication, and gastric ulcer were excluded. Time-fixed Cox model with one-to-one propensity score matching was used to calculate hazard ratio (HR) of GC with CCBs. Sensitivity analysis using time-dependent multivariable Cox model in which CCB use was treated as time-varying covariate was also performed to address immortal time bias. 17 622 (29.6%) H pylori-eradicated patients with hypertension were included. During a median follow-up of 8.6 years, 105 (0.6%) developed GC. After PS matching, CCBs were associated with a lower GC risk (HR: 0.56; 95% CI: 0.32-0.97). Time-dependent analysis showed consistent result (aHR: 0.50; 95% CI: 0.33-0.75). A longer duration of CCB use was associated with even lower GC risk (adjusted HR [aHR]: 0.69; 95% CI: 0.61-0.79 for every 1-year increase in use). Long-acting CCBs (aHR: 0.47; 95% CI: 0.29-0.76) and dihydropyridines (aHR: 0.49; 95% CI: 0.32-0.73) conferred greater benefit than short-acting ones (aHR: 0.60; 95% CI: 0.36-1.03) and nondihydropyridines (aHR: 0.76; 95% CI: 0.24-2.48). The aHR was 0.57 (95% CI: 0.34-0.97) for noncardia and 0.59 (95% CI: 0.27-1.31) for cardia cancer. Use of CCBs was associated with lower risk of GC development in H pylori-eradicated patients, in a duration- and dose-response manner.

Lesions missed by colonoscopy are one of the main reasons for post-colonoscopy colorectal cancer, which is usually associated with a worse prognosis. Because the adenoma miss rate could be as high as 26%, it has been noted that endoscopists with higher adenoma detection rates are usually associated with lower adenoma miss rates. Artificial intelligence (AI), particularly the deep learning model, is a promising innovation in colonoscopy. Recent studies have shown that AI is not only accurate in colorectal polyp detection but can also reduce the miss rate. Nevertheless, the application of AI in real-time detection has been hindered by heterogeneity of the AI models and study design as well as a lack of long-term outcomes. Herein, we discussed the principle of various AI models and systematically reviewed the current data on the use of AI on colorectal polyp detection and miss rates. The limitations and future prospects of AI on colorectal polyp detection are also discussed.

Purpose Comparative gastrointestinal bleeding (GIB) risk between rivaroxaban and low-dose aspirin is unknown in patients with atrial fibrillation (AF). This study investigated GIB risk with rivaroxaban vs aspirin among two separate AF cohorts in Hong Kong and the United Kingdom, using a common protocol approach. Methods This was a population-based cohort study using separate data from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority (2010-2018) and The Health Improvement Network (THIN) database in the United Kingdom (2011-2017). Patients with AF newly prescribed aspirin or rivaroxaban were included. Cox proportional hazards regression was used to compare GIB risks for rivaroxaban vs aspirin, accounting for confounders using propensity score fine stratification approach. Results In CDARS, 29 213 patients were included; n = 1052 (rivaroxaban), n = 28 161 (aspirin). Crude GIB event rates per 100 patient-years in CDARS were 3.0 (aspirin) and 2.6 (rivaroxaban). No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.04, 95%CI = 0.76-1.42), and in dose-stratified analyses (HR = 1.21, 95%CI = 0.84-1.74 [20 mg/day]; HR = 0.80, 95%CI = 0.44-1.45 [≤15 mg/day]). In THIN, 11 549 patients were included, n = 3496 (rivaroxaban) and n = 8053 (aspirin). Crude GIB event rates were 1.3 (aspirin) and 2.4 (rivaroxaban) per 100 patient-years. No difference in GIB risk was observed between rivaroxaban and aspirin overall (HR = 1.40, 95%CI = 1.00-1.98) and low-dose rivaroxaban (≤15 mg/day) (HR = 1.00, 95%CI = 0.56-1.30), but increased GIB risk was observed for rivaroxaban 20 mg/day vs aspirin (HR = 1.57, 95%CI = 1.08-2.29). Conclusion In patients with AF, GIB risk was comparable between aspirin and rivaroxaban ≤15 mg/day. GIB risk for rivaroxaban 20 mg/day vs aspirin remains uncertain and warrants further investigation.

Background Elderly-onset inflammatory bowel disease [IBD], defined as age ≥60 at diagnosis, is increasing worldwide. We aimed to compare clinical characteristics and natural history of elderly-onset IBD patients with those of adult-onset IBD patients. Methods Patients with a confirmed diagnosis of IBD from 1981 to 2016 were identified from a territory-wide Hong Kong IBD registry involving 13 hospitals. Demographics, comorbidities, clinical features, and outcomes of elderly-onset IBD patients were compared with those of adult-onset IBD patients. Results A total of 2413 patients were identified, of whom 270 [11.2%] had elderly-onset IBD. Median follow-up duration was 111 months (interquartile range [IQR]: 68–165 months). Ratio of ulcerative colitis [UC]: Crohn’s disease [CD] was higher in elderly-onset IBD than in adult-onset IBD patients [3.82:1 vs 1.39:1; p Conclusions Elderly-onset IBD was associated with increased risk of infections and cancer development, and increased infection- and IBD-related hospitalisations. Specific therapeutic strategies to target this special population are needed.

Performance of endoscopic procedures is associated with a risk of infection from COVID-19. This risk can be reduced by the use of personal protective equipment (PPE). However, shortage of PPE has emerged as an important issue in managing the pandemic in both traditionally high and low-resource areas. A group of clinicians and researchers from thirteen countries representing low, middle, and high-income areas has developed recommendations for optimal utilization of PPE before, during, and after gastrointestinal endoscopy with particular reference to low-resource situations. We determined that there is limited flexibility with regard to the utilization of PPE between ideal and low-resource settings. Some compromises are possible, especially with regard to PPE use, during endoscopic procedures. We have, therefore, also stressed the need to prevent transmission of COVID-19 by measures other than PPE and to conserve PPE by reduction of patient volume, limiting procedures to urgent or emergent, and reducing the number of staff and trainees involved in procedures. This guidance aims to optimize utilization of PPE and protection of health care providers.

Whether ACE (angiotensin-converting enzyme) inhibitors and angiotensin receptor blockers modify colorectal cancer risk remains controversial. We aimed to determine association between their use and colorectal cancer risk after a negative baseline colonoscopy. This is a territory-wide retrospective cohort study recruiting patients aged ≥40 who had undergone colonoscopy between 2005 and 2013. Exclusion criteria included colorectal cancer detected 3years (adjusted hazard ratio, 1.18 [95% CI, 0.88–1.57]); every single year increase in the drug use was associated with 5% reduction in adjusted hazard ratio risk. ACE inhibitors/angiotensin receptor blocker were associated with a lower colorectal cancer risk in a duration-response manner.

Background We aimed to study the prevalence of secondary antibiotic resistance of Helicobacter pylori in southern China and its risk factors, particularly geographical and socio-economic factors. Methods This was a municipality-wide, multicentre, prospective cohort study involving five major hospitals. Patients aged ≥18 years who failed first-line bismuth-based quadruple anti-H. pylori therapy between September 2016 and February 2018 were recruited. Participants underwent upper gastrointestinal endoscopy with biopsy from the antrum and body for H. pylori culture and antimicrobial susceptibility testing for six antibiotics (clarithromycin, levofloxacin, metronidazole, amoxicillin, tetracycline and furazolidone). Patients with failure of H. pylori culture were excluded. Participants completed a questionnaire profiling 22 potential risk factors of H. pylori infection and antibiotic resistance, including medical, social, household and birthplace factors. Results A total of 1113 patients failed first-line therapy, with successful H. pylori culture in 791 (71.1%) [male = 433 (54.7%); median age = 43 years]. Secondary resistance rates of dual antibiotics (clarithromycin + metronidazole and levofloxacin + metronidazole) and triple antibiotics (clarithromycin + levofloxacin + metronidazole) were 34.0%, 38.7% and 17.8%, respectively. Risk factors for clarithromycin + metronidazole resistance were history of ≥2 courses of H. pylori therapies [adjusted OR (aOR) = 1.71; 95% CI = 1.17–2.54], ≥3 household members (aOR = 2.00; 95% CI = 1.07–3.90) and family history of gastric cancer (aOR = 1.85; 95% CI = 1.18–2.85). Risk factors for levofloxacin + metronidazole resistance were age ≥40 years (aOR = 1.94; 95% CI = 1.37–2.75), lower gross domestic product per capita (aOR = 0.29; 95% CI = 0.10–0.80) and higher number of doctors/10 000 population (aOR = 1.59; 95% CI = 1.07–2.39). A higher human development index was of borderline significance (aOR = 2.79; 95% CI = 0.97–8.70). Conclusions The rates of secondary resistance of H. pylori to multiple antibiotics were high in southern China. Certain population-level risk factors were associated with levofloxacin + metronidazole resistance.

To investigate the association between T helper 2 (Th2) cell regulatory and effector molecules’ genetic polymorphisms and periodontitis. Single nucleotide polymorphisms (SNPs) of 11 Th2 cell regulatory or effector molecules genes (CD28, CTLA4, IL4, IL5, IL6, IL9, IL10, IL13, IL4R, GATA3, STAT6, and rs1537415; total 130 SNPs) were studied in Chinese nonsmokers (163 periodontitis-free controls, 141 periodontitis patients) using Sequenom iPlex assays. SNPs potentially associated with periodontitis (adjusted allelic P < 0.1) in this cross-sectional study were further investigated via meta-analysis. Allele G of rs4553808 in promoter of CTLA4 was more frequently detected in periodontitis than controls (P < 0.005), but did not remain significant after age and gender adjustment. Haplotype (GTT) in a block of three CTLA4 SNPs (rs4553808, rs16840252, rs5742909) was significantly associated with periodontitis. Meta-analysis of SNPs identified indicated allele T of CTLA4 rs5742909 (3 studies; 461 control, 369 periodontitis) and allele G of IL6 rs1800796 (18 studies; 2760 control, 2442 periodontitis) were significantly associated with periodontitis (OR = 1.44 and OR = 1.30, respectively). Within limitations of this study, a haplotype of CTLA4 concerning Th2 cell regulation, may be associated with periodontitis in Chinese nonsmokers followed. Meta-analysis indicated rs5742909 of CTLA4 and rs1800796 of IL6 appeared significantly associated with periodontitis.

Background The mesencephalic trigeminal nucleus (Vmes) is not only anatomically adjacent to the locus coeruleus (LC) but is also tightly associated with the function of the LC. The LC can be the first area in which Alzheimer's disease (AD) develops, although it is unclear how LC neuronal loss occurs. Objective We investigated whether neuronal death in the Vmes can be spread to adjacent LC in female triple transgenic (3×Tg)-AD mice, how amyloid-β (Aβ) is involved in LC neuronal loss, and how this neurodegeneration affects cognitive function. Methods The molars of 3×Tg-AD mice were extracted, and the mice were reared for one week to 4 months. Immunohistochemical analysis, and spatial learning/memory assessment using the Barnes maze were carried out. Results In 4-month-old 3×Tg-AD mice, aggregated cytotoxic Aβ42 was found in granules in Vmes neurons. Neuronal death in the Vmes occurred after tooth extraction, resulting in the release of cytotoxic Aβ42 and an increase in CD86 immunoreactive microglia. Released Aβ42 damaged the LC, in turn inducing a significant reduction in hippocampal neurons in the CA1 and CA3 regions receiving projections from the LC. Based on spatial learning/memory assessment, after the tooth extraction in the 4-month-old 3×Tg-AD mice, increased latency was observed in 5-month-old 3×Tg-AD mice 1 month after tooth extraction, which is similar increase of latency observed in control 8-month-old 3×Tg-AD mice. Measures of cognitive deficits suggested an earlier shift to dementia-like behavior after tooth extraction. Conclusion These findings suggest that tooth extraction in the predementia stage can trigger the spread of neurodegeneration from the Vmes, LC, and hippocampus and accelerate the onset of dementia.

Inflammatory bowel disease (IBD) has increased in incidence and prevalence in Asian countries since the end of the 20th century. Moreover, differences in the cause, phenotypes, and natural history of IBD between the East and West have been recognized. Therefore, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have established recommendations on medical management of IBD in Asia. Initially, the committee members drafted 40 recommendations, which were then assessed according to Grading of Recommendations Assessment, Development and Evaluation. Eight statements were rejected as this indicated that consensus had not been reached. The recommendations encompass pretreatment evaluation; medical management of active IBD; medical management of IBD in remission; management of IBD during the periconception period and pregnancy; surveillance strategies for colitis-associated cancer; monitoring side effects of thiopurines and methotrexate; and infections in IBD.

The COVID‐19 pandemic, secondary to SARS‐CoV‐2, has resulted in high mortality and morbidity worldwide. As inflammatory bowel disease (IBD) is a chronic disease, and most patients are on long‐term immunosuppressive agents, there is understandable concern, particularly in terms of therapy. In view of this, experts in IBD across the Asia Pacific region were invited to put together recommendations based on their experience and the currently available data. In general, most IBD therapies (with a few exceptions) can be continued safely, and the general consensus is that maintaining disease control should remain the main principle of management. In addition, social distancing measures and the appropriate use of personal protective equipment should be strictly adhered to. During the current pandemic, face‐to‐face clinic follow ups and non‐urgent procedures should be kept to a minimum., This is a concerted effort by the members of the Asian Pacific Association of Gastroenterology Inflammatory Bowel Disease (IBD) Workgroup members to provide guidance on IBD management (all‐in‐one succinct review paper) during the difficult COVID‐19 pandemic.

With the increasing use of nonsteroidal anti-inflammatory drugs (NSAIDs), the incidence of lower gastrointestinal (GI) complications is expected to increase. However, unlike up per GI complications, the burden, pathogenesis, prevention and treatment of NSAID-associated lower GI complications remain unclear. To date, no cost-effective and safe protec tive agent has been developed that can completely prevent or treat NSAID-related lower GI injuries. Selective COX-2 in hibitors, misoprostol, intestinal microbiota modulation, and some mucoprotective agents have been reported to show protective effects on NSAID-induced lower GI injuries. This re view aims to provide an overview of the current evidence on the prevention of NSAID-related lower GI injuries. (Gut Liver 2020;14:179-189)

Background: Individuals may still develop gastric cancer even after Helicobacter pylori eradication. We aimed to investigate statin effect on gastric cancer development in H. pylori–eradicated subjects. Methods: All adult subjects who were prescribed clarithromycin-based triple therapy between 2003 and 2012 were identified in this retrospective cohort study utilizing a territory-wide electronic healthcare database. Patients were observed from index date of H. pylori therapy, and censored at gastric cancer diagnosis, death, or December 2015 (study end date). Statin use was defined as ≥180-day use after index date. Exclusion criteria included gastric cancer diagnosed within the first year after index date, previous gastric cancer or gastrectomy, and H. pylori treatment failure. Subdistribution hazard ratio (SHR) of gastric cancer with statins was calculated by competing risk regression with propensity score (PS) analysis matching 19 variables (age, sex, comorbidities, and other drug usage, including proton pump inhibitors, nonsteroidal anti-inflammatory drugs, aspirin, cyclooxygenase-2 inhibitors, and metformin). Results: During a median follow-up of 7.6 years (interquartile range = 5.1–10.3), 169 (0.27%) of 63,605 patients developed gastric cancer at an incidence rate of 3.5 per 10,000 person-years. Among 22,870 PS-matched subjects, statins were associated with a lower gastric cancer risk (SHR = 0.34; 95% confidence interval, 0.19–0.61), in a duration– and dose–response manner (Ptrend < 0.05). Conclusions: Statins were associated with a lower gastric cancer risk in a duration– and dose–response manner among H. pylori–eradicated patients. Impact: This study provides evidence on the additional benefits of statins as chemopreventive agents against gastric cancer among H. pylori–eradicated patients.

The object of this chapter was to provide an overview including relevant research progress of some genetic disorders with periodontal manifestations. A number of genetic disorders increase patient susceptibility to periodontal disease, with the latter exhibit rather rapid and aggressive presentations. Periodontal disease, perhaps could be the first detectable sign of an undiagnosed genetic disorder. It is therefore important for dental practitioners to be familiar with genetic disorders and their impact on the periodontal tissues. This chapter reviews several genetic disorders that exhibit periodontal manifestations, including hereditary gingival fibromatosis, Papillon-Lefèvre syndrome, cyclic neutropenia, Ehlers-Danlos syndrome and hypophosphatasia.

Failure rates of clarithromycin-containing triple therapy for H. pylori are rising. To determine the trend of failure rates of clarithromycin-containing triple therapy in different age groups in Hong Kong over the past 15 years.This is a population-based retrospective age-period-cohort study involving all adult H. pylori-infected patients who had received the first course of clarithromycin-containing triple therapy in 2003-2017. Failed eradication was identified by the need of retreatment within 2 years of eradication. Logistic regression model was used to characterize the risk of retreatment.113,526 H. pylori-infected patients were included. The overall failure rate increased from 4.83% in 2003 to 10.2% in 2016 (p for linear trend0.001). When stratified by age of eradication, patients 75 years or above had the lowest retreatment rate of 5.11%, which progressively increased in younger patients (60-74 years: OR 1.26, 95% CI 1.15-1.38; 45-59 years: OR 1.36, 95% CI 1.24-1.48; 18-44 years: OR 1.55, 95% CI 1.41-1.69). The results remained consistent when stratified by year of birth, and period of eradication. Other risk factors for retreatment included female (OR 1.24, 95% CI 1.18-1.30), triple therapy containing metronidazole (OR 2.30, 95% CI 2.12-2.50), and shorter duration of therapy (10 days: OR 0.88, 95% CI 0.79-0.97; 14 days: OR 0.67, 95% CI 0.58-0.77 vs 7 days).While failure rates of clarithromycin-containing triple therapy progressively increased over the past 15 years, the failure rate was particularly high among younger patients, which could undermine the potential benefits of early H. pylori eradication.

Gut microbiota is increasingly recognized to play a pivotal role in various human physiological functions and diseases. Amidst the COVID-19 pandemic, research has suggested that dysbiosis of the gut microbiota is also involved in the development and severity of COVID-19 symptoms by regulating SARS-CoV-2 entry and modulating inflammation. Previous studies have also suggested that gut microbiota and their metabolites could have immunomodulatory effects on vaccine immunogenicity, including influenza vaccines and oral rotavirus vaccines. In light of these observations, it is possible that gut microbiota plays a role in influencing the immune responses to COVID-19 vaccinations via similar mechanisms including effects of lipopolysaccharides, flagellin, peptidoglycan, and short-chain fatty acids. In this review, we give an overview of the current understanding on the role of the gut microbiota in COVID-19 manifestations and vaccine immunogenicity. We then discuss the limitations of currently published studies on the associations between gut microbiota and COVID-19 vaccine outcomes. Future research directions shall be focused on the development of microbiota-based interventions on improving immune response to SARS-CoV-2 infection and vaccinations.