Cigarette Smoke Increases Risk for Colorectal Neoplasia in Inflammatory Bowel Disease

Examining the relationship between secondhand smoke and non-malignant digestive system diseases: Mendelian randomization evidence

INTRODUCTION

Secondhand smoke (SHS) may exacerbate the global disease burden, particularly in workplace settings. Observational studies have implicated SHS as a risk factor for various non-malignant digestive system diseases (NMDSD), yet establishing a causal relationship remains challenging. Therefore, we conducted a Mendelian randomization (MR) study to explore whether workplace exposure to SHS is associated with NMDSD.

METHODS

This study utilized a secondary dataset analysis based on Genome-Wide association study (GWAS) summary data. Genetic variants associated with exposure to SHS in the workplace were used as instrumental variables. Genome-wide association study (GWAS) summary data for SHS were obtained from the UK Biobank. GWAS summary data for NMDSD were sourced from the FinnGen study, the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC), and a large-scale study conducted in Japan. We employed inverse variance-weighted (IVW), MR-Egger, and weighted median methods for MR analysis. Additionally, sensitivity analyses were conducted to ensure the robustness of our findings.

RESULTS

According to the IVW model, SHS in the workplace was positively associated with ulcerative colitis (UC) (OR=2.03; 95% CI: 1.03-4.05; p=0.04). There was no evidence of horizontal pleiotropy biasing causality (p>0.05), and leave-one-out analysis confirmed the stability and robustness of this association.

CONCLUSIONS

Our study identifies an association between regular exposure to SHS in the workplace and an increased risk of ulcerative colitis. However, the potential influence of active smoking or exposure to SHS from other sources cannot be excluded. Further research is needed to confirm these findings.

Duration of smoking cessation in patients with inflammatory bowel disease

BACKGROUND AND OBJECTIVES

Smoking can worsen inflammatory bowel disease (IBD), although evidence regarding the duration of cessation is scarce. The objectives of the study were to determine the duration of abstinence and identify the characteristics of relapse in IBD patients.

PATIENTS AND METHODS

Using the local database of a nationwide registry of patients with IBD, we identified patients who were active smokers at the time of IBD diagnosis and invited them to participate in the study. Patients were asked about their smoking habit and those who were ex-smokers constituted the study cohort. We obtained clinical and smoking-related data of ex-smokers from medical records and telephone interviews. We measured nicotine dependence using the Fagerström Test for Nicotine Dependence (FTND).

RESULTS

We enrolled 121 IBD patients who were ex-smokers: 89 patients with Crohn's disease (CD) and 33 patients with ulcerative colitis (UC). The median age at cessation was lower in patients with CD (38 years) than in patients with UC (46 years) (p=0.002). Follow-up time was shorter in CD patients than in UC patients (114 vs. 168 months, p=0.035). No difference was found in the FTND score. Relapse was more common in CD patients (46%) than in UC patients (24%) (p=0.029), although time to first relapse was similar in both groups of patients (12 and 15 months, respectively; p=0.056). Nicotine dependence was the only independent factor associated with relapse.

CONCLUSIONS

The risk of smoking relapse was high, especially in CD patients, although their dependence level was similar to that of UC patients.

Longer Colonoscopy Withdrawal Time Is Associated With the Detection of Visible Dysplasia in Patients With Inflammatory Bowel Disease

Background

Colonoscopy withdrawal time (CWT) of at least 6-9 minutes is the minimum time needed for adequate adenoma detection in the general population. The ideal CWT in patients with inflammatory bowel disease (IBD) has not been determined. We aimed to identify the optimal CWT associated with the detection of visible dysplasia in patients with IBD.

Methods

This is a retrospective study from 1/1/2017 to 9/1/2022 of adult patients with IBD in endoscopic healing undergoing surveillance via high-definition white light colonoscopy. The primary outcome was the association of CWT with visible dysplasia detection.

Results

A total of 259 patients (mean age 56 ± 14.8 years; 51.3% female, 68% with ulcerative colitis; 8.9% with primary sclerosing cholangitis) underwent 330 colonoscopies. Patients with visible dysplasia were more likely to be older (P < .001) and have a personal history of visible dysplasia (P < .001) and invisible dysplasia (P = .023). The mean CWT was significantly longer in the visible dysplasia group at 26 minutes (interquartile range [IQR] 20-38.5) vs. 21 minutes (IQR 15-28) in procedures without visible dysplasia (P < .001). On multivariable analysis, increased age (P < .001), increased CWT (P = .001), and personal history of visible dysplasia (P = .013) were independently associated with the detection of visible dysplasia. A CWT of ≥15 minutes (odds ratio [OR] 2.71; 95% confidence interval [CI], 1.11-6.6; P = .02] and not ≥9 minutes (OR 2.57; 95% CI, 0.33-20.2; P = .35) is significantly associated with detection of visible dysplasia.

Conclusions

For patients with IBD undergoing surveillance via high-definition white light colonoscopy, the mean CWT was independently associated with the detection of visible dysplasia.

Assessing the Efficacy of Fenugreek Saponin Nanoparticles in Attenuating Nicotine-Induced Hepatotoxicity in Male Rats

During smoking, nicotine, the most bountiful compound in cigarettes, is absorbed into the body by the lungs and quickly metabolized in the liver, causing three major adverse impacts such as toxic, neoplastic, and immunomodulatory effects. Saponins extracted from several plants are reported to exhibit various biological actions, such as anticancer effects. So, the potential protective effect of fenugreek saponin and nanofenugreek saponin against toxicity induced by nicotine in male rats was investigated in this study. Animals were exposed to nicotine (1.5 mg/kg/day) and/or treated with fenugreek saponin (25, 50, and 100 mg/kg/day) and nanofenugreek saponin (20, 40, and 80 mg/kg/day). Comet assays, histopathological examination, and analyses for the expression levels of glutamate aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) genes in liver tissues as well as the activity of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were conducted. The results revealed that nicotine treatment induced a significant increase in DNA damage, decrease in the expression levels of (GLAST) and (GLT-1) genes, and increase in histopathological alterations in liver tissues. Moreover, nicotine treatment induced a significant reduction in the activity of antioxidant enzymes GPx and GST. On the other hand, administration of fenugreek saponin or nanofenugreek saponin with nicotine significantly decreased the DNA damage, increased the expression levels of (GLAST) and (GLT-1) genes, and decreased histopathological alterations in liver tissues. Additionally, a significant increase in the activities of GPx and GST was observed. The results suggested that DNA damage and histological injuries induced by nicotine were decreased by the administration of fenugreek saponin or nanofenugreek saponin; thus, fenugreek saponin and nanofenugreek saponin can be used as ameliorative agents against nicotine toxicity.

A critical review on inflammatory bowel diseases risk factors, dietary nutrients regulation and protective pathways based on gut microbiota during recent 5 years

The treatment of inflammatory bowel diseases (IBDs) has become a worldwide problem. Intestinal flora plays an important role in the development and progression of IBDs. Various risk factors (psychology, living habits, dietary patterns, environment) influence the structure and composition of the gut microbiota and contribute to the susceptibility to IBDs. This review aims to provide a comprehensive overview on risk factors regulating intestinal microenvironment which was contributed to IBDs. Five protective pathways related to intestinal flora were also discussed. We hope to provide systemic and comprehensive insights of IBDs treatment and to offer theoretical guidance for personalized patients with precision nutrition.

Risk factors for colorectal cancer in IBD patients

A characteristic feature of inflammatory bowel diseases (IBD) is an increased risk of neoplasia and colorectal cancer (CRC). The introduction of screening programs, as well as modern advances in therapy and endoscopic technologies, awareness of the risk factors of IBD-associated CRC will contribute to reducing the frequency of this dangerous complication of IBD. The presented review describes epidemiological data on the incidence of IBD-associated CRC, established risk factors for CRC, as well as modern methods of prevention, screening and early diagnosis. Literature search was conducted in PubMed and Google Scholar systems by keywords: inflammatory bowel diseases, ulcerative colitis, Crohn’s disease, colorectal cancer, risk factors, screening, endoscopy, dysplasia.

Identifying celiac disease-related chemicals by transcriptome-wide association study and chemical-gene interaction analyses

Celiac disease (CeD) is one of the most common intestinal inflammatory diseases, and its incidence and prevalence have increased over time. CeD affects multiple organs and systems in the body, and environmental factors play a key role in its complex pathogenesis. Although gluten exposure is known to be the causative agent, many unknown environmental factors can trigger or exacerbate CeD. In this study, we investigated the influence of genetic and environmental factors on CeD. Data from a CeD genome-wide association study that included 12,041 CeD cases and 12,228 controls were used to conduct a transcriptome-wide association study (TWAS) using FUSION software. Gene expression reference data were obtained for the small intestine, whole blood, peripheral blood, and lymphocytes. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses using the significant genes identified by the TWAS and conducted a protein–protein interaction network analysis based on the STRING database to detect the function of TWAS-identified genes for CeD. We also performed a chemical-related gene set enrichment analysis (CGSEA) using the TWAS-identified genes to test the relationships between chemicals and CeD. The TWAS identified 8,692 genes, including 101 significant genes (p_adjusted < 0.05). The CGSEA identified 2,559 chemicals, including 178 chemicals that were significantly correlated with CeD. This study performed a TWAS (for genetic factors) and CGSEA (for environmental factors) and identified several CeD-associated genes and chemicals. The findings expand our understanding of the genetic and environmental factors related to immune-mediated diseases.

High-Dimensional DNA Methylation Mediates the Effect of Smoking on Crohn's Disease

Epigenome-wide mediation analysis aims to identify high-dimensional DNA methylation at cytosine-phosphate-guanine (CpG) sites that mediate the causal effect of linking smoking with Crohn's disease (CD) outcome. Studies have shown that smoking has significant detrimental effects on the course of CD. So we assessed whether DNA methylation mediates the association between smoking and CD. Among 103 CD cases and 174 controls, we estimated whether the effects of smoking on CD are mediated through DNA methylation CpG sites, which we referred to as causal mediation effect. Based on the causal diagram, we first implemented sure independence screening (SIS) to reduce the pool of potential mediator CpGs from a very large to a moderate number; then, we implemented variable selection with de-sparsifying the LASSO regression. Finally, we carried out a comprehensive mediation analysis and conducted sensitivity analysis, which was adjusted for potential confounders of age, sex, and blood cell type proportions to estimate the mediation effects. Smoking was significantly associated with CD under odds ratio (OR) of 2.319 (95% CI: 1.603, 3.485, p < 0.001) after adjustment for confounders. Ninety-nine mediator CpGs were selected from SIS, and then, seven candidate CpGs were obtained by de-sparsifying the LASSO regression. Four of these CpGs showed statistical significance, and the average causal mediation effects (ACME) were attenuated from 0.066 to 0.126. Notably, three significant mediator CpGs had absolute sensitivity parameters of 0.40, indicating that these mediation effects were robust even when the assumptions were slightly violated. Genes (BCL3 and FKBP5) harboring these four CpGs were related to CD. These findings suggest that changes in methylation are involved in the mechanism by which smoking increases risk of CD.

The outcome of patients with inflammatory bowel disease-associated colorectal cancer is not worse than that of patients with sporadic colorectal cancer-a matched-pair analysis of survival

PURPOSE

Patients with inflammatory bowel disease (IBD) have an increased risk for colorectal cancer (CRC). In IBD patients, cancer is often diagnosed in advanced stages and conflicting data on survival compared to sporadic CRC have been reported. The aim of this study was to directly compare clinical characteristics and prognosis of patients with IBD-CRC and sporadic CRC.

METHODS

The clinical and pathological data of 63 patients with IBD-CRC and 3710 patients with sporadic CRC treated at the University Hospital of Erlangen between 1995 and 2015 were compared. Forty-seven M0 patients with IBD were matched with sporadic CRC patients after curative resection (R0) according to tumor localization, stage, sex, and year of treatment. Overall and disease-free survival were compared.

RESULTS

Sixty-three patients presented IBD-CRC. Fifty were affected with ulcerative colitis (UC) and 13 with Crohn's disease (CD). CRC was diagnosed within 1.45 years since last endoscopic surveillance. Twelve patients (19%) had a diagnosis of primary sclerosing cholangitis. In matched analysis, IBD patients were diagnosed with CRC at younger age compared to sporadic CRC and were more likely to have right-sided CRC (40% versus 23.3%) and rare histological subtypes (19% versus 9.2%). No differences in 5-year overall (78.7 versus 80.9 months) and 5-year disease-free survival (74.5 versus 70.2 months) were noted.

CONCLUSION

IBD-CRC patients were younger and more frequently had right-sided carcinomas compared to sporadic CRC. CRC in IBD patients did not show survival difference compared to matched-pair sporadic CRC patients without distant metastases after curative resection. Surveillance might be important for early detection of CRC in IBD patients.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.