Influence of diabetes mellitus on inflammatory bowel disease course and treatment outcomes. A systematic review with meta-analysis

Impact of Helicobacter pylori Eradication on Inflammatory Bowel Disease Onset and Disease Activity: To Eradicate or Not to Eradicate?

Helicobacter pylori infection has significant epidemiological relevance due to the carcinogenic nature of this bacterium, which is potentially associated with cancer. When detected, it should ideally be eradicated using a treatment that currently involves a combination of gastric acid suppressors and multiple antibiotics. However, this treatment raises questions regarding efficacy and safety profiles in patients with specific comorbidities, including inflammatory bowel diseases (IBD). Eradication therapy for H. pylori includes components associated with adverse gastrointestinal events, such as Clostridioides difficile colitis. This necessitates quantifying this risk through dedicated studies to determine whether this antimicrobial treatment could be significantly associated with IBD relapse or exacerbation of pre-existing IBD, as well as whether it could potentially lead to the de novo onset of IBD. Although the available evidence is reassuring about the safety of eradication therapy in patients with IBD, it is limited, and there are no specific recommendations for this particular situation in the leading international IBD and H. pylori guidelines. Therefore, studies need to evaluate the efficacy and safety profiles of the available antimicrobial regimens for H. pylori eradication in patients with IBD, both in clinical trial settings and in real-life studies.

The causal relationship between anti-diabetic drugs and gastrointestinal disorders: a drug-targeted mendelian randomization study

BACKGROUND

The incidence of diabetic gastrointestinal diseases is increasing year by year. This study aimed to investigate the causal relationship between antidiabetic medications and gastrointestinal disorders, with the goal of reducing the incidence of diabetes-related gastrointestinal diseases and exploring the potential repurposing of antidiabetic drugs.

METHODS

We employed a two-sample Mendelian randomization (TSMR) design to investigate the causal association between antidiabetic medications and gastrointestinal disorders, including gastroesophageal reflux disease (GERD), gastric ulcer (GU), chronic gastritis, acute gastritis, Helicobacter pylori infection, gastric cancer (GC), functional dyspepsia (FD), irritable bowel syndrome (IBS), ulcerative colitis (UC), Crohn's disease (CD), diverticulosis, and colorectal cancer (CRC). To identify potential inhibitors of antidiabetic drug targets, we collected single-nucleotide polymorphisms (SNPs) associated with metformin, GLP-1 receptor agonists, SGLT2 inhibitors, DPP-4 inhibitors, insulin, and its analogs, thiazolidinediones, sulfonylureas, and alpha-glucosidase inhibitors from published genome-wide association study statistics. We then conducted a drug-target Mendelian randomization (MR) analysis using inverse variance weighting (IVW) as the primary analytical method to assess the impact of these inhibitors on gastrointestinal disorders. Additionally, diabetes was selected as a positive control.

RESULTS

Sulfonylureas were found to significantly reduce the risk of CD (IVW: OR [95% CI] = 0.986 [0.978, 0.995], p = 1.99 × 10- 3), GERD (IVW: OR [95% CI] = 0.649 [0.452, 0.932], p = 1.90 × 10- 2), and chronic gastritis (IVW: OR [95% CI] = 0.991 [0.982, 0.999], p = 4.50 × 10- 2). However, they were associated with an increased risk of GU development (IVW: OR [95%CI] = 2 0.761 [1.259, 6.057], p = 1 0.12 × 10- 2).

CONCLUSIONS

The results indicated that sulfonylureas had a positive effect on the prevention of CD, GERD, and chronic gastritis but a negative effect on the development of gastric ulcers. However, our research found no causal evidence for the impact of metformin, GLP-1 agonists, SGLT2 inhibitors, DPP 4 inhibitors, insulin and its analogs, thiazolidinediones, or alpha-glucosidase inhibitors on gastrointestinal diseases.

Type II diabetes mellitus increases the risk of inflammatory bowel disease in a prospective cohort study

BACKGROUND

Inflammatory bowel disease is a common digestive disorder and diabetes can lead to intestinal dysfunction. Patients with inflammatory bowel disease in combination with diabetes present a higher rate of hospitalization and consumption of medical resources, yet the association between type 2 diabetes and Inflammatory bowel disease remains unknown.

METHODS

We studied 313,008 participants from the UK Biobank, including 5891 patients with type 2 diabetes at baseline. Multivariate Cox proportional risk models were constructed to examine the risks associated with type 2 diabetes and inflammatory bowel disease and its subtypes (Crohn's disease, ulcerative colitis). Potential confounders including sociodemographic, lifestyle, physical body indicators, psychological state, hypertension, and thyroid-related disorders were adjusted. Propensity score matching was also performed to analyze their sensitivity.

RESULTS

Of a total of 313,008 participants included in the study, 5891 (1.88 %) were diagnosed with type 2 diabetes mellitus at baseline and 1829 (0.58 %) of the entire cohort developed inflammatory bowel disease during follow-up, with a median follow-up time of 13.72 years. Patients with type 2 diabetes had a higher cumulative risk of inflammatory bowel disease compared to the non-type 2 diabetes population (inflammatory bowel disease: 1.24% vs. 0.57%, p < 0.001; Crohn's disease: 0.46% vs. 0.15%, p < 0.001; ulcerative colitis: 0.73% vs. 0.35%, p < 0.001). Multivariate Cox regression analysis showed that type 2 diabetes was independently associated with inflammatory bowel disease (Hazard Ratio: 1.61 [95% Confidence Interval: 1.26-2.06], p < 0.001), Crohn's disease (Hazard Ratio: 2.10 [95% Confidence Interval: 1.39-3.17], p < 0.001) and ulcerative colitis (Hazard Ratio: 1.58 [95% Confidence Interval: 1.15-2.18], p = 0.005). In a propensity-matched analysis, type 2 diabetes still showed its ability to predict the risk of inflammatory bowel disease (Hazard Ratio: 2.09 [95% Confidence Interval: 1.55-2.83], p < 0.001), Crohn's disease (Hazard Ratio: 3.49 [95% Confidence Interval: 2.00 to 6.09], p < 0.001), and ulcerative colitis (Hazard Ratio: 1.76 [95% Confidence Interval: 1.20 to 2.56], p = 0.003) of robustness.

CONCLUSION

In patients with type 2 diabetes mellitus, the risk of inflammatory bowel disease is higher, and the presence of gastrointestinal symptoms in patients with type 2 diabetes requires vigilance for the possibility of inflammatory bowel disease in clinical practice.

Type 2 diabetes and inflammatory bowel disease: a bidirectional two-sample Mendelian randomization study

To investigate the association between T2DM and IBD by bidirectional two-sample Mendelian randomization (MR) to clarify the casual relationship. Independent genetic variants for T2DM and IBD were selected as instruments from published genome-wide association studies (GWAS), mainly in European ancestry. Instrumental variables (IVs) associated with T2DM and IBD were extracted separately from the largest GWAS meta-analysis. MR analyses included inverse variance weighting, weighted median estimator, MR Egger regression, and sensitivity analyses with Steiger filtering and MR PRESSO. In the data samples for Ulcerative colitis (UC) (6968 cases, 20,464 controls) and Crohn's disease (CD) (5956 cases, 14,927 controls), there was a negative causal relationship between T2DM and UC [IVW, OR/95%CI: 0.882/(0.826,0.942), p < 0.001]. However, the causal relationships between T2DM and CD, UC and T2DM, CD and T2DM were not significant, and the p value measured by the IVW method was ≥ 0.05. All SNPs showed no significant horizontal pleiotropy (p > 0.05). The results of the bidirectional MR Study suggest that T2DM has a negative causal effect on UC, which provides implications for clinical treatment decisions in IBD patients with T2DM. The findings do not support a causal relationship between T2DM and CD, UC and T2DM, or CD and T2DM, and the impact of IBD on T2DM needs further investigation.

Causal linkage between type 2 diabetes mellitus and inflammatory bowel disease: an integrated Mendelian randomization study and bioinformatics analysis

Background

Observational studies have indicated associations between type 2 diabetes mellitus (T2DM) and both colorectal cancer (CRC) and inflammatory bowel disease (IBD). However, the underlying causality and biological mechanisms between these associations remains unclear.

Methods

We conducted a bidirectional Mendelian randomization (MR) analysis employing summary statistics from genome-wide association studies involving European individuals. The inverse variance weighting (IVW) method was the primary method used to assess causality. Additionally, we applied MR Egger, Weighted median, Simple mode, and Weighted mode to evaluate the robustness of the results. Outliers were identified and eliminated using the MR-PRESSO, while the MR-Egger intercept was used to assess the horizontal pleiotropic effects of single nucleotide polymorphisms (SNPs). The heterogeneity was evaluated using the Cochrane Q test, and sensitivity analysis was performed using leave-one-out method. The F statistic was calculated to evaluate weak instrumental variable bias. Finally, a pilot bioinformatics analysis was conducted to explore the underlying biological mechanisms between T2DM and IBD/UC.

Results

The IVW results demonstrated that T2DM significantly reduced risks of IBD (OR=0.885, 95% CI: 0.818-0.958, P=0.002) and ulcerative colitis (UC) (OR=0.887, 95% CI: 0.812-0.968, P=0.007). Although the 95% CIs of MR Egger, Weighted median, Simple mode, and Weighted mode were broad, the majority of their estimates were consistent with the direction of IVW. Despite significant heterogeneity among SNPs, no horizontal pleiotropy was observed. The leave-one-out analysis showed that the causality remained consistent after each SNP was removed, underscoring the reliability of the results. Reverse MR analysis indicated that genetic susceptibility to both CRC and IBD had no significant effect on the relative risk of T2DM. Ten hub genes were identified, which mainly enriched in pathways including maturity onset diabetes of the young, thyroid cancer, gastric acid secretion, longevity regulating pathway, melanogenesis, and pancreatic secretion.

Conclusion

The presence of T2DM does not increase the risk of CRC or IBD. Moreover, T2DM might reduce risk of IBD, including UC. Conversely, the occurrence of CRC or IBD does not influence the risk of T2DM. The association between T2DM and IBD/UC may be related to the changes in multiple metabolic pathways and CTLA-4-mediated immune response.

Diabetes exacerbates inflammatory bowel disease in mice with diet-induced obesity

BACKGROUND

The increased prevalence of inflammatory bowel disease (IBD) among patients with obesity and type 2 diabetes suggests a causal link between these diseases, potentially involving the effect of hyperglycemia to disrupt intestinal barrier integrity.

AIM

To investigate whether the deleterious impact of diabetes on the intestinal barrier is associated with increased IBD severity in a murine model of colitis in mice with and without diet-induced obesity.

METHODS

Mice were fed chow or a high-fat diet and subsequently received streptozotocin to induce diabetic-range hyperglycemia. Six weeks later, dextran sodium sulfate was given to induce colitis. In select experiments, a subset of diabetic mice was treated with the antidiabetic drug dapagliflozin prior to colitis onset. Endpoints included both clinical and histological measures of colitis activity as well as histochemical markers of colonic epithelial barrier integrity.

RESULTS

In mice given a high-fat diet, but not chow-fed animals, diabetes was associated with significantly increased clinical colitis activity and histopathologic markers of disease severity. Diabetes was also associated with a decrease in key components that regulate colonic epithelial barrier integrity (colonic mucin layer content and epithelial tight junction proteins) in diet-induced obese mice. Each of these effects of diabetes in diet-induced obese mice was ameliorated by restoring normoglycemia.

CONCLUSION

In obese mice, diabetes worsened clinical and pathologic outcomes of colitis via mechanisms that are reversible with treatment of hyperglycemia. Hyperglycemia-induced intestinal barrier dysfunction offers a plausible mechanism linking diabetes to increased colitis severity. These findings suggest that effective diabetes management may decrease the clinical severity of IBD.

Colorectal cancer among inflammatory bowel disease patients: risk factors and prevalence compared to the general population

Background

Colorectal cancer (CRC) is a feared complication of inflammatory bowel disease (IBD). We aimed to investigate the prevalence and risk factors of CRC among a large cohort of IBD patients.

Methods

Data on IBD patients free of CRC at baseline was extracted using the MDClone platform of the Clalit health maintenance organization in Israel. We investigated the frequency rate of CRC among IBD patients compared to a control group without IBD. Possible risk factors, including comorbidities and IBD-related medications, were investigated in a multivariate analysis.

Results

During a follow-up of 139,448 years among Crohn's disease (CD) patients and 139,533 years among ulcerative colitis (UC) patients, a frequency rate of CRC was 1.5% (191) among 12,888 CD patients and 2.1% (261) among 12,381 UC patients compared to 1.2% among 57,334 controls. In a multivariate analysis of UC patients, age at diagnosis (OR 1.030, p < 0.001), primary sclerosing cholangitis (OR 2.487, p = 0.005), diabetes mellitus (OR 2.01, p < 0.001), and glucocorticoids treatment (OR 1.465, p = 0.008) were found to be predictors of CRC. For CD patients, age at diagnosis (OR 1.035, p < 0.001), primary sclerosing cholangitis (OR 2.25, p = 0.029), and glucocorticoids treatment (OR 2.07, p < 0.001) were found to be predictors for CRC, but not diabetes mellitus.

Conclusion

Despite the continuously decreasing rates of CRC among IBD patients, these are still higher in IBD patients compared to the general population. IBD patients, particularly those with risk factors, require special consideration in follow-up for CRC.

The Melanocortin System in Inflammatory Bowel Diseases: Insights into Its Mechanisms and Therapeutic Potentials

The melanocortin system is a complex set of molecular mediators and receptors involved in many physiological and homeostatic processes. These include the regulation of melanogenesis, steroidogenesis, neuromodulation and the modulation of inflammatory processes. In the latter context, the system has assumed importance in conditions of chronic digestive inflammation, such as inflammatory bowel diseases (IBD), in which numerous experiences have been accumulated in mouse models of colitis. Indeed, information on how such a system can counteract colitis inflammation and intervene in the complex cytokine imbalance in the intestinal microenvironment affected by chronic inflammatory damage has emerged. This review summarises the evidence acquired so far and highlights that molecules interfering with the melanocortin system could represent new drugs for treating IBD.

Quality of bowel preparation in patients with inflammatory bowel disease undergoing colonoscopy: What factors to consider?

An adequate bowel preparation in patients with inflammatory bowel disease (IBD) is a prerequisite for successful colonoscopy for screening, diagnosis, and surveillance. Several bowel preparation formulations are available, both high- and low-volume based on polyethylene glycol. Generally, low-volume formulations are also based on several compounds such as magnesium citrate preparations with sodium picosulphate, oral sulphate solution, and oral sodium phosphate-based solutions. Targeted studies on the quality of bowel preparation prior to colonoscopy in the IBD population are still required, with current evidence from existing studies being inconclusive. New frontiers are also moving towards the use of alternatives to anterograde ones, using preparations based on retrograde colonic lavage.