Evaluating the relationship between Helicobacter pylori infection

Infection with Helicobacter pylori may predispose to atherosclerosis: role of inflammation and thickening of intima-media of carotid arteries

Atherosclerosis is a major instigator of cardiovascular disease (CVD) and a main cause of global morbidity and mortality. The high prevalence of CVD calls for urgent attention to possible preventive measures in order to curb its incidence. Traditional risk factors of atherosclerosis, like age, smoking, diabetes mellitus, dyslipidemia, hypertension and chronic inflammation, are under extensive investigation. However, these only account for around 50% of the etiology of atherosclerosis, mandating a search for different or overlooked risk factors. In this regard, chronic infections, by Helicobacter pylori for instance, are a primary candidate. H. pylori colonizes the gut and contributes to several gastrointestinal diseases, but, recently, the potential involvement of this bacterium in extra-gastric diseases including CVD has been under the spotlight. Indeed, H. pylori infection appears to stimulate foam cell formation as well as chronic immune responses that could upregulate key inflammatory mediators including cytokines, C-reactive protein, and lipoproteins. These factors are involved in the thickening of intima-media of carotid arteries (CIMT), a hallmark of atherosclerosis. Interestingly, H. pylori infection was found to increase (CIMT), which along with other evidence, could implicate H. pylori in the pathogenesis of atherosclerosis. Nevertheless, the involvement of H. pylori in CVD and atherosclerosis remains controversial as several studies report no connection between H. pylori and atherosclerosis. This review examines and critically discusses the evidence that argues for a potential role of this bacterium in atherogenesis. However, additional basic and clinical research studies are warranted to convincingly establish the association between H. pylori and atherosclerosis.

Helicobacter pylori and cardiovascular risk: Only a dead Helicobacter is a good Helicobacter?

OBJECTIVES

Helicobacter pylori (H. pylori) and cardiovascular (CV) disease share common symptoms and underlie many general medical complaints. Preliminary studies suggest an association between H. pylori positivity and CV risk, and gastroenterological guidelines recommend eradication of H. pylori in patients with manifest atherosclerosis. Therefore, the aim of this study was to examine the reciprocal association of H. pylori positivity and CV risk for their independence of shared risk factors.

METHODS

We included 3284 asymptomatic participants of a colorectal cancer screening cohort who were offered and underwent upper gastrointestinal endoscopy. We calculated the 10-year risk for a CV event using the novel SCORE2 for each patient. We evaluated the association between H. pylori positivity and CV risk assessed by SCORE2 using both multilevel logistic and linear regression. We adjusted for age, sex and the concomitant diagnosis of metabolic syndrome. Lastly, we assessed the association between H. pylori status and mortality using proportional hazard Cox regression.

RESULTS

In total, 2659 patients were H. pylori negative and 625 H. pylori positive. Helicobacter pylori positivity was associated with SCORE2 and remained so (r = .33; 95% CI 0.09-0.57; p = .006) after adjustment for age, sex, and the diagnosis of metabolic syndrome. Also, SCORE2 was associated with higher odds for H. pylori positivity (aOR 1.03 95% CI 1.01-1.05; p = .02) even after multivariable adjustment. Helicobacter pylori positivity was associated with neither CV (HR 0.60 95% CI 0.14-2.63; p = .50) nor all-cause (HR 1.20 95% CI 0.77-1.87; p = .43) mortality during a median follow-up of 9 years.

CONCLUSIONS

In our study, H. pylori positivity and CV risk were independently associated. This did not translate into a dissimilar CV mortality between H. pylori positive and H. pylori negative patients. However, the overwhelming majority of our patients underwent H. pylori eradication. We, therefore, think that H. pylori eradication is at least safe from a cardiovascular perspective and warranted from gastrointestinal standpoint.

Helicobacter Pylori Infection Induces Intestinal Dysbiosis That Could Be Related to the Onset of Atherosclerosis

Cardiovascular diseases represent one of the first causes of death around the world, and atherosclerosis is one of the first steps in the development of them. Although these problems occur mainly in elderly, the incidence in younger people is being reported, and an undetermined portion of patients without the classic risk factors develop subclinical atherosclerosis at earlier stages of life. Recently, both the H. pylori infection and the intestinal microbiota have been linked to atherosclerosis. The mechanisms behind those associations are poorly understood, but some of the proposed explanations are (a) the effect of the chronic systemic inflammation induced by H. pylori, (b) a direct action over the endothelial cells by the cytotoxin associated gene A protein, and (c) alterations of the lipid metabolism and endothelial dysfunction induced by H. pylori infection. Regarding the microbiota, several studies show that induction of atherosclerosis is related to high levels of Trimethylamine N-oxide. In this review, we present the information published about the effects of H. pylori over the intestinal microbiota and their relationship with atherosclerosis and propose a hypothesis to explain the nature of these associations. If H. pylori contributes to atherosclerosis, then interventions for eradication and restoration of the gut microbiota at early stages could represent a way to prevent disease progression.

Are Any Changes in Carotid Intima–Media Thickness Associated with Cardiometabolic Risk Among Adult Bantu Central African Hypertensive Patients from Monkole and Biamba Marie Mutombo Hospitals?

Background

Several classic/traditional risk factors are associated with intima–media thickness (IMT), a novel risk of cardio metabolic risk (CMR) in the literature but not in Kinshasa, a megacity prone to CMR. Thus, the objective of this study was to evaluate potential correlations between inflammation, kidney function, psychological stress, hemodynamics, and changes in IMT.

Methods

This cross-sectional study was carried out between 2018 and 2021 within Monkole and Biamba Marie Mutombo Hospitals, respectively, and randomly selected from 10 health structures from East and West of Kinshasa, Capital of Democratic Republic Congo (DRC). A random sample of adult hypertensive Bantu Central Africans was examined after bivariate correlations and multiple linear regression.

Results

Out of 280 patients with 140 men and 140 women aged 62 ± 11 years, the mean carotid intima–media thickness (CIMT) was 1.06 ± 0.5 mm and 73% (n = 204) patients had uncontrolled hypertension. After controlling for confounders, 52.9% variations (R2) of CIMT were independently and significantly (P = 0.037) predicted by CRP, 24-hour proteinuria, urinary albumin/creatinine ratio, duration of hypertension, heart rate, hip circumference, and psychological stress with Equation Y = 0.717 + 0.87 × CRP + 0.02 × 24 H – proteinuria + 0.005 × urinary albumin/creatinine ratio + 0.05 × duration of hypertension + 0.001 × heart rate + 0.006 × hip circumference + 0.017 × psychological stress.

Conclusion

There is an urgent need to control inflammation, impaired renal function, cardiac rhythm, peripheral obesity, longer duration of hypertension management, and stress, which are emerging as specific novel determinants of the subclinical atherosclerosis for those Bantu Central African hypertensive patients.

Transgenically expressed Helicobacter pylori CagA in vascular endothelial cells accelerates arteriosclerosis in mice

Arteriosclerosis is intimately associated with cardiovascular diseases. Recently, evidence accumulated that infection with Helicobacter pylori cagA-positive strains, which causes gastritis, peptic ulceration, and gastric cancer, is also involved in the development of arteriosclerosis. The cagA-encoded CagA protein is injected into the attached gastric epithelial cells via the type IV secretion system. We previously showed that CagA-containing exosomes are secreted from CagA-injected gastric epithelial cells and enter the systemic blood circulation, delivering CagA into endothelial cells. In the present study, transgenic mice were established in which CagA was selectively expressed in endothelial cells by Cre-loxP system. Treatment of the mice with a high-fat diet revealed that atherogenic lesions were induced in mice expressing CagA in vascular endothelial cells but not in CagA-nonexpressing mice. To investigate the effects of CagA on endothelial cells, we also established conditional CagA-expressing human vascular endothelial cells using the Tet-on system. Upon induction of CagA, a dramatic change in cell morphology was observed that was concomitantly associated with the loss of the endothelial cells to form tube-like structures. Induction of CagA also activated the pro-inflammatory transcription factor STAT3. Thus, exosome-delivered CagA deregulates signals that activates STAT3 in endothelial cells, which accelerates inflammation that promotes arteriosclerosis/atherosclerosis.

Helicobacter pylori infection and the progression of atherosclerosis: A systematic review and meta-analysis

OBJECTIVE

In recent years, many studies have tried to prove whether Helicobacter pylori (H. pylori) can promote the progression of atherosclerosis (AS), but the reported results are conflicting. Carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), or pulse wave velocity (PWV) are the most commonly used indicators to evaluate the progress of AS. So, we collected and evaluated these three indicators to provide evidence-based medicine for the clinic.

MATERIALS AND METHODS

We included and evaluated studies on H. pylori infection and CIMT, FMD, or PWV from PubMed, Cochrane trials, and Embase databases before September 1, 2021, and language restrictions: English. Research types include cross-sectional studies, cohort studies, and case-control studies. The MINORS scale was used to evaluate the quality of these studies. For all studies, we choose a random-effects model and calculate the weighted mean difference (WMD) for analysis, and all our analyses use STATA software.

RESULTS

Meta-analysis shows that H. pylori infection can significantly increase CIMT (WMD = 0.059, 95% CI: 0.039, 0.079, p < 0.001). Based on subgroup analysis, we found that the relationship between the two is more significant in the young and middle-aged people younger than 60 years old and people without cardiovascular disease. In addition, we also found an association between H. pylori infection and FMD (WMD = -3.873, 95% CI: -5.684, -2.062, p < 0.001), but it is a pity that there are few literatures that meet the standards. Finally, We concluded that H. pylori infection can significantly increase PWV (WMD = 88.033, 95%CI: 67.297,108.768. I²  = 99.63%, p < 0.001). In the subgroup analysis, we also found that this correlation is similar to CIMT, and it is more significant in the young and middle-aged population under 60 and those without cardiovascular disease. We also found in the sub-analysis that there was a significant increase in CIMT in CagA-positive individuals in H. pylori-infected patients (WMD = 0.16, 95%CI: 0.02, 0.29. p = 0.03).

CONCLUSION

Helicobacter pylori infection can promote the process of AS, especially in people under the age of 60 and people without cardiovascular risk factors, and we hope that our meta-analysis can provide ideas for the early prevention of AS.