Co-morbid diabetes in patients with Crohn's disease predicts a greater need for surgical intervention

Pathogens in Crohn's Disease: The Role of Adherent Invasive Escherichia coli

In Crohn's disease (CD), gut dysbiosis is marked by the prevalence of pathogenic bacterial species. Although several microbes have been reported as risk factors or causative agents of CD, it is not yet clear which is the real trigger of the disease. Thirty years ago, a new pathovar of Escherichia coli strain was isolated in the ileal mucosa of CD patients. This strain, called adherent invasive E. coli (AIEC), for its ability to invade the intestinal mucosa, could represent the causative agent of the disease. Several authors studied the mechanisms by which the AIEC penetrate and replicate within macrophages, and release inflammatory cytokines sustaining inflammation. In this review we will discuss about the role of AIEC in the pathogenesis of CD, the virulence factors mediating adhesion and invasion of AIEC in mucosal tissue, the environmental conditions improving AIEC survival and replication within macrophages. Finally, we will also give an overview of the new strategies developed to limit AIEC overgrowth.

Cardiovascular manifestations of inflammatory bowel diseases and the underlying pathogenic mechanisms

Inflammatory bowel disease (IBD), consisting of ulcerative colitis and Crohn's disease, mainly affects the gastrointestinal tract but is also known to have extraintestinal manifestations because of long-standing systemic inflammation. Several national cohort studies have found that IBD is an independent risk factor for the development of cardiovascular disorders. However, the molecular mechanisms by which IBD impairs the cardiovascular system are not fully understood. Although the gut-heart axis is attracting more attention in recent years, our knowledge of the organ-to-organ communication between the gut and the heart remains limited. In patients with IBD, upregulated inflammatory factors, altered microRNAs and lipid profiles, as well as dysbiotic gut microbiota, may induce adverse cardiac remodeling. In addition, patients with IBD have a three- to four times higher risk of developing thrombosis than people without IBD, and it is believed that the increased risk of thrombosis is largely due to increased procoagulant factors, platelet count/activity, and fibrinogen concentration, in addition to decreased anticoagulant factors. The predisposing factors for atherosclerosis are present in IBD and the possible mechanisms may involve oxidative stress system, overexpression of matrix metalloproteinases, and changes in vascular smooth muscle phenotype. This review focuses mainly on 1) the prevalence of cardiovascular diseases associated with IBD, 2) the potential pathogenic mechanisms of cardiovascular diseases in patients with IBD, and 3) adverse effects of IBD drugs on the cardiovascular system. Also, we introduce here a new paradigm for the gut-heart axis that includes exosomal microRNA and the gut microbiota as a cause for cardiac remodeling and fibrosis.

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

BACKGROUND

Diabetes Mellitus (DM) may occur in IBD and influence the disease progression.

AIM

To compare disease course and treatment outcomes in IBD patients with and without DM.

METHODS

This is a systematic review with meta-analysis comparing patients with IBD plus DM with patients with IBD only.

PRIMARY ENDPOINTS

need for surgery, IBD-related complications, hospitalizations, sepsis, mortality. Quality of life and costs were assessed.

RESULTS

Five studies with 71,216 patients (49.1% with DM) were included. Risk for IBD-related complications (OR=1.12, I² 98% p = 0.77), mortality (OR=1.52, I² 98% p = 0.37) and IBD-related surgery (OR=1.20, I² 81% p = 0.26) did not differ. Risk of IBD-related hospitalizations (OR=2.52, I² 0% p < 0.00001) and sepsis (OR=1.56, I² 88% p = 0.0003) was higher in the IBD+DM group. Risk of pneumonia and urinary tract infections was higher in the IBD+DM group (OR=1.72 and OR=1.93), while risk of C. Difficile infection did not differ (OR=1.22 I² 88% p = 0.37). Mean Short Inflammatory Bowel Disease Questionnaire score was lower in the IBD+DM group (38.9 vs. 47, p = 0.03). Mean health care costs per year were $10,598.2 vs $3747.3 (p < 0.001).

CONCLUSION

DM might negatively affect the course of IBD by increasing the risk of hospitalization and infections, but not IBD-related complications and mortality.

Review article: The aetiology of fatigue in inflammatory bowel disease and potential therapeutic management strategies

BACKGROUND

Fatigue is the inability to achieve or maintain an expected work output resulting from central or peripheral mechanisms. The prevalence of inflammatory bowel disease (IBD) fatigue can reach 86% in active disease, persisting in 50%-52% of patients with mild to inactive disease. Fatigue is the commonest reason for work absence in IBD, and patients often report fatigue burden to be greater than that of primary disease symptoms. Relatively few evidence-based treatment options exist, and the aetiology is poorly understood.

AIM

To review the available data and suggest a possible aetiology of IBD fatigue and to consider the efficacy of existing management strategies and highlight potential future interventions.

METHODS

We reviewed fatigue-related literature in IBD using PubMed database.

RESULTS

Disease related factors such as inflammation and pharmacological treatments negatively impact skeletal muscle and brain physiology, likely contributing to fatigue symptoms. Secondary factors such as malnutrition, anaemia, sleep disturbance and psychological comorbidity are potential determinants. Immune profile, faecal microbiota composition and physical fitness differ significantly between fatigued and non-fatigued patients, suggesting these may be aetiological factors. Solution-focused therapy, high-dosage thiamine supplementation and biological therapy may reduce fatigue perception in IBD. The effect of physical activity interventions is inconclusive.

CONCLUSIONS

A multimodal approach is likely required to treat IBD fatigue. Established reversible factors like anaemia, micronutrient deficiencies and active disease should initially be resolved. Psychosocial intervention shows potential efficacy in reducing fatigue perception in quiescent disease. Restoring physical deconditioning by exercise training intervention may further improve fatigue burden.

Comorbid Diabetes in Inflammatory Bowel Disease Predicts Adverse Disease-Related Outcomes and Infectious Complications

BACKGROUND

Diabetes mellitus (DM) and inflammatory bowel diseases (IBD) are chronic systemic illnesses associated with chronic inflammation, dysbiosis, impaired immune function, and infection risk. The impact of DM in modifying disease activity in patients with IBD remains largely unknown.

AIM

To investigate the impact of DM on IBD-related disease outcomes, mortality, and infections in patients with IBD.

METHODS

We performed a longitudinal cohort analysis. Using a large institutional database, patients with concurrent IBD and DM (IBD-DM), and IBD without DM (IBD cohort), were identified and followed longitudinally to evaluate for primary (IBD-related) and secondary (mortality and infections) outcomes. Cox proportional hazards models were used to determine the independent effect of DM on each outcome, adjusting for confounding effects of covariates.

RESULTS

A total of 901 and 1584 patients were included in the IBD-DM and DM cohorts. Compared with IBD, IBD-DM had significantly higher risk of IBD-related hospitalization [adjusted hazard ratio (HR) 1.97, 95% confidence interval (1.71-2.28)], disease flare [HR 2.05 (1.75-2.39)], and complication [HR 1.54 (1.29-1.85)]. No significant difference was observed in the incidence of IBD-related surgery. All-cause mortality, sepsis, Clostridioides difficile infection (CDI), pneumonia, urinary tract infection, and skin infection were also more frequent in the IBD-DM than the IBD cohort (all p ≤ 0.05). Subgroup analysis of Crohn's disease (CD) and ulcerative colitis patients showed similar associations, except with an additional risk of surgery and no association with CDI in the CD-DM cohort.

CONCLUSION

Comorbid diabetes in patients with IBD is a predictor of poor disease-related and infectious outcomes.

Obesity in IBD: epidemiology, pathogenesis, disease course and treatment outcomes

Incidence of IBD is rising in parallel with overweight and obesity. Contrary to conventional belief, about 15-40% of patients with IBD are obese, which might contribute to the development of IBD. Findings from cross-sectional and retrospective cohort studies are conflicting on the effect of obesity on natural history and course of IBD. Most studies are limited by small sample size, low event rates, non-validated assessment of disease activity and lack robust longitudinal follow-up and have incomplete adjustment for confounding factors. The effect of obesity on the efficacy of IBD-related therapy remains to be studied, though data from other autoimmune diseases suggests that obesity results in suboptimal response to therapy, potentially by promoting rapid clearance of biologic agents leading to low trough concentrations. These data provide a rationale for using weight loss interventions as adjunctive therapy in patients with IBD who are obese. Obesity also makes colorectal surgery technically challenging and might increase the risk of perioperative complications. In this Review, we highlight the existing literature on the epidemiology of obesity in IBD, discuss its plausible role in disease pathogenesis and effect on disease course and treatment response, and identify high-priority areas of future research.

Systematic review with meta-analysis: the adverse effects of tobacco smoking on the natural history of Crohn's disease

BACKGROUND

Tobacco smoking is a well-established risk factor for the development of Crohn's disease, and this may lead to a more complicated disease course. However, recent evidence suggests that many patients with Crohn's disease are unaware of this fact.

AIM

To perform a systematic review and meta-analysis of the effects of smoking on disease course in Crohn's disease.

METHODS

A search of MEDLINE, EMBASE and EMBASE classic was carried out (up to July 2015) to identify observational studies reporting data on smoking and rates of surgery or flares of disease activity in patients with Crohn's disease. Dichotomous data were pooled to obtain odds ratios (ORs) for flares of disease activity or need for surgery, with 95% confidence intervals (CIs).

RESULTS

The search identified 33 eligible studies. Compared with nonsmokers, smokers had increased odds of flare of disease activity (OR, 1.56; 95% CI, 1.21-2.01), flare after surgery (OR, 1.97; 95% CI, 1.36-2.85), need for first surgery (OR, 1.68; 95% CI, 1.33-2.12) and need for second surgery (OR, 2.17; 95% CI, 1.63-2.89). The odds of these outcomes among ex-smokers diminished upon smoking cessation, with ORs comparable to those among nonsmokers and, in the case of flare or second surgery, significantly lower than smokers.

CONCLUSIONS

Smokers with Crohn's disease have a more complicated disease course than nonsmokers, and quitting smoking may ameliorate this. Patients should be reminded of the detrimental effects of smoking on the course of their disease, and smoking cessation advice should be provided to reduce disease burden and costs in these patients.

Impact of metabolic syndrome on the hospitalization rate of Crohn's disease patients seen at a tertiary care center: a retrospective cohort study

BACKGROUND/AIMS

Recent studies suggest that markers of mesenteric inflammation, such as increased adipose tissue, may be associated with poor outcomes in Crohn's disease (CD). This study's hypothesis is that CD patients with metabolic syndrome (MetS) have more CD-related hospitalizations than CD patients without MetS.

METHODS

We conducted a retrospective cohort study of CD patients seen from 2000 to 2012 at our tertiary care center. We analyzed crude and age-, sex- and duration of CD-adjusted incidence rate ratio (IRR) of CD-related hospitalization of those with MetS versus those without MetS. We also investigated possible associations between individual component conditions of MetS and rate of CD-related hospitalization.

RESULTS

A total of 868 CD patients were included. There were 37 (4%) patients with MetS at initial observation. After multi-variable adjustment, patients with MetS had a CD-related hospitalization rate twice that of those who did not have MetS. High triglycerides (TG), low high density lipoprotein (HDL) cholesterol and diabetes mellitus (DM) were associated with increased risk of CD-related hospitalization.

CONCLUSIONS

CD patients with MetS have a higher rate of CD-related hospitalization compared to those without MetS. Hypertriglyceridemia, low HDL cholesterol and DM may be good markers of local and systemic inflammation as seen in CD.

Anti-inflammatory mechanism of metformin and its effects in intestinal inflammation and colitis-associated colon cancer

BACKGROUND AND AIM

The aim of this study is to evaluate the effect of metformin on intestinal inflammation.

METHODS

COLO205 cells were pretreated with metformin and stimulated with tumor necrosis factor (TNF)-α. Expression of interleukin (IL)-8 was determined by luciferase assay and real-time PCR. Inhibitor of kappaB (IκB) phosphorylation/degradation and adenosine monohosphate-activated protein kinase (AMPK) activity were evaluated by Western blotting. DNA-binding activity of transcription factor nuclear factor-kappaB (NF-κB) was assessed by electrophoretic mobility shift assay. In an acute colitis model, mice were given 4% dextran sulfate sodium (DSS) for 5 days. IL-10−/− mice were used to evaluate the effect of metformin on chronic colitis. In an inflamation-associated tumor model, mice were given a single intraperitoneal injection of azoxymethane followed by three cycles of 2% DSS for 5 days and 2 weeks of free water consumption.

RESULTS

Metformin significantly inhibited IL-8 induction in COLO 205 cells stimulated with TNF-α. Metformin attenuated IκBα phosphorylation and NF-κB DNA-binding activity. Administration of metformin significantly reduced the severity of DSS-induced colitis. In addition, DSS-induced IκB kinase (IKK) activation was significantly reduced in mice treated with metformin. Metformin significantly attenuated the severity of colitis in IL-10−/− mice, induced AMPK activity in intestinal epithelial cells, and inhibited the development of colitic cancer in mice.

CONCLUSIONS

These results indicate that metformin suppresses NF-κB activation in intestinal epithelial cells and ameliorates murine colitis and colitis-associated tumorigenesis in mice, suggesting that metformin could be a potential therapeutic agent for the treatment of inflammatory bowel disease.

Switching from insulin to liraglutide improved glycemic control and the quality of life scores in a case of type 2 diabetes and active Crohn's disease

A 44-year-old man with type 2 diabetes of five years' duration was admitted for the management of poor glycemic control despite the administration of insulin therapy. On admission, he received vigorous treatment for a 28-year history of Crohn's disease and a 14-year history of a psychiatric disorder. His glycosylated hemoglobin A1c (HbA1c) level was 11.3%, his fasting blood glucose level was 567 mg/dL and his C-peptide level was 1.0 ng/mL. His quality of life (QOL) was severely impaired as a result of frequent episodes of hyperglycemia and hypoglycemia. Treatment with liraglutide was commenced in place of insulin, which improved the patient's glycemic control to an HbA1c level of 5.5% and markedly increased his QOL score with no hypoglycemia.