Prospective relations between Helicobacter pylori infection, coronary heart disease, and stroke in middle aged men

Risk of Ischemic Stroke in Relation to Helicobacter pylori Infection and Eradication Status: A Large-Scale Prospective Observational Cohort Study

Background/Aims

: A few studies have suggested the association between Helicobacter pylori (HP) infection and ischemic stroke. However, the impact of HP eradication on stroke risk has not been well evaluated. This study aimed to assess the influence of HP eradication on the incidence of ischemic stroke, considering the potential effect of sex.

Methods

: This prospective observational cohort study was conducted at Seoul National University Bundang Hospital, from May 2003 to February 2023, and involved gastroscopy-based HP testing. Propensity score (PS) matching was employed to ensure balanced groups by matching patients in the HP eradicated group (n=2,803) in a 3:1 ratio with patients in the HP non-eradicated group (n=960). Cox proportional hazard regression analysis was used to evaluate the risk of ischemic stroke.

Results

: Among 6,664 patients, multivariate analysis after PS matching indicated that HP eradication did not significantly alter the risk of ischemic stroke (hazard ratio, 0.531; 95% confidence interval, 0.221 to 1.270; p=0.157). Sex-specific subgroup analyses, both univariate and multivariate, did not yield statistically significant differences. However, Kaplan-Meier analysis revealed a potential trend: the females in the HP eradicated group exhibited a lower incidence of ischemic stroke than those in the HP non-eradicated group, although this did not reach statistical significance (p=0.057).

Conclusions

: This finding suggests that HP eradication might not impact the risk of ischemic stroke. However, there was a trend showing that females potentially had a lower risk of ischemic stroke following HP eradication, though further investigation is required to establish definitive evidence.

Association between Helicobacter pylori infection and triglyceride levels: a nested cross-sectional study

Background

Currently, the available evidence regarding the relationship between the lipid profile and Helicobacter pylori (H. pylori) infection is limited and conflicting. There is also a dearth of studies that have explored the possibility of sex-specific differences in the association between H. pylori infection and triglyceride levels.

Methods

We conducted a cross-sectional study involving 1,146 participants utilizing data from the National Health and Nutrition Examination Survey (NHANES) 1999-2000 conducted in the United States. A logistic regression model was employed to evaluate the association between H. pylori seropositivity and triglyceride levels. Subgroup analyses stratified by sex were conducted to explore sex-specific differences in this association.

Results

Serum triglyceride levels were significantly higher in H. pylori-seropositive participants than in H. pylori-seronegative participants. In the logistic regression analysis, there was a positive correlation between H. pylori seropositivity and triglyceride levels (OR=1.231; 95% CI, 1.016-1.491; P=0.033). In the subgroup analysis, the adjusted association between serum triglycerides and H. pylori seropositivity was significant in females (OR=1.732; 95% CI, 1.113-2.696; P=0.015) but not in males (OR=1.091; 95% CI, 0.698-1.705; P=0.704).

Conclusion

The association between high triglyceride levels and H. pylori infection is specific to the female population.

An Updated Meta-Analysis of the Relationship Between Helicobacter pylori Infection and the Risk of Coronary Heart Disease

Background

Coronary heart disease (CHD) is one of the leading causes of mortality in the world. Although the traditional risk factors for CHD have been identified, it seems that there are still many CHD cases without these factors. Previous studies have hypothesized that Helicobacter pylori (H. pylori) infection was associated with the risk of CHD.

Objective

The association between H. pylori infection and the risk of CHD was studied using a systematic evaluation and meta-analysis method.

Methods

In order to find relevant studies, four electronic databases were systematically searched until August 2021. According to the inclusion and exclusion criteria, studies were screened and data were extracted. Under the random-effects or the fixed-effects model, the odds ratio (OR) and 95% confidence interval (95% CI) were combined. All analyses were conducted using Review Manager software (RevMan 5.4).

Results

Among the included studies, 2 studies were analyzed for H. pylori stool antigen test, 2 studies were analyzed for H. pylori histological staining test, 13 studies were analyzed for the anti-CagA test, and 38 studies were analyzed for the anti-H. pylori IgG test. The pooled results revealed that positive anti-H. pylori IgG was significantly associated with an increased risk of CHD (OR, 1.58; 95% CI: 1.34–1.87). Similarly, positive anti-CagA, positive H. pylori stool antigen, and positive H. pylori histological staining were significantly associated with the development of CHD with (OR: 1.33, 95% CI: 1.16–1.53), (OR: 3.50, 95% CI: 1.60–7.66), and (OR: 1.78, 95% CI: 1.12–2.83), respectively.

Conclusion

This meta-analysis showed that H. pylori infection increased the risk of CHD. However, more studies are needed to further investigate whether early eradication of H. pylori may reduce the morbidity of CHD.

Relationship between Helicobacter pylori and Incident Hypertension as well as Blood Pressure: A Systematic Review and Meta-Analysis

BACKGROUND

Helicobacter pylori (H. pylori) may be a risk factor for hypertension, but the reported studies have given conflicting results. This study aimed to explore the association between H. pylori infection and hypertension risk and blood pressure.

METHOD

PubMed, Embase, Web of Science, CNKI, Weipu, and Wanfang databases were searched for articles published up to June 2, 2021. Dual-selection and data abstraction were conducted. Random-effect models were used to measure pooled estimates. All data were analyzed with Stata 14.0 SE (StataCorp, College Station, TX, USA).

RESULTS

A total of 55 studies with 198,750 individuals were included in the meta-analysis. Among them, 33 studies reported the relationship between H. pylori infection and the risk of hypertension, and 25 studies reported the association of H. pylori infection with systolic blood pressure (SBP) and diastolic blood pressure (DBP). Three studies reported both of the above. Meta-analysis showed that H. pylori infection increased the risk of hypertension by 32% (odd ratio: 1.32, 95% CI: 1.15-1.52). Compared with non-H. pylori-infection individuals, the subjects with H. pylori infection had elevated levels of SBP (WMD: 1.86, 95% CI: 1.21-2.50) and DBP (WMD: 1.12, 95% CI: 0.81-1.43).

CONCLUSION

This meta-analysis suggested that H. pylori infection increased the risk of hypertension. This may provide a new strategy for hypertension prevention. However, the association between H. pylori infection and hypertension needs to be confirmed in further prospective cohort studies.

Potential association between bacterial infections and ischemic stroke based on fifty case-control studies: a systematic review and meta-analysis

Background

Stroke is considered as one of the most important concerns in health care centers around the world. By definition there are two types of stroke including ischemic stroke and hemorrhagic stroke. Approximately three-quarters of stroke cases are ischemic strokes, which occur due to several risk factors such as hypertension, obesity, atherosclerosis, diabetes mellitus, osteoarthritis, and inflammatory responses. In recent years, infectious diseases have noticed as a new risk factor for ischemic stroke. Given the importance of the issue, some bacteria that cause chronic infections, especially Chlamydia pneumonia, Helicobacter pylori, Mycoplasma pneumonia, Mycobacterium tuberculosis, and Coxiella burnetii have been considered.

Methods

In the present meta-analysis, we reviewed 50 case-control studies and assessed the possible association of bacterial infections with the occurrence of ischemic stroke.

Results

We analyzed the information of 33,978 participants in several nested case-control studies, and ultimately showed that bacterial infections could increase the risk of ischemic stroke. Our results suggest that bacterial infections significantly increase in the risk of ischemic stroke (OR: 1.704; 1.57-1.84 with 95% CIs; p value = 0.01).

Conclusions

In this meta-analysis, a significant relationship was observed between infection by three bacteria such as C. pneumoniae, H. pylori, and M. tuberculosis with the occurrence of ischemic stroke. Furthermore, due to the similarity between TLRVYK domain in β2-glycoprotein-I and TLRVYK peptide in various of microorganisms, produced antibodies against pathogens interact with β2-glycoprotein-I, hence the cross-reaction phenomenon increases the positive relationship between infectious diseases and ischemic stroke.

Helicobacter pylori Infection Is Associated With Carotid Intima and Media Thickening: A Systematic Review and Meta-Analysis

Background

Helicobacter pylori (H. pylori) infection affects ≈4.4 billion people worldwide. Several studies suggest that this pathogen impacts the digestive system, causing diverse and severe conditions, and results in extragastrointestinal disorders like vascular diseases. Our study aims to examine the association between H. pylori infection and carotid intima‐media thickness.

Methods and Results

Electronic databases (MEDLINE, Embase, CENTRAL, Web of Science, and Scopus) were searched for studies, comparing the thickness of the carotid intima‐media in H. pylori–infected and noninfected individuals listed until October 20, 2020. Statistical analyses were performed using the random effects meta‐analysis of model of weighted mean differences with the corresponding 95% CI using the DerSimonian and Laird method. The protocol was registered in advance in PROSPERO (International Prospective Register of Systematic Reviews; CRD42021224485). Thirteen studies were found meeting inclusion criteria for our systematic review and meta‐analysis, presenting data on the thickness of the carotid intima‐media considering the presence of H. pylori infection. Altogether, 2298 individuals’ data were included (1360 H. pylori positive, 938 negative). The overall carotid intima‐media thickness was significantly larger among infected patients compared with uninfected participants (weighted mean difference: 0.07 mm; 95% CI, 0.02–0.12; P=0.004; I²=91.1%; P<0.001). In case of the right common carotid artery, the intima‐media thickening was found to be significant as well (weighted mean difference, 0.08 mm; 95% CI, 0.02–0.13, P=0.007; I²=85.1%; P<0.001), while it showed no significance in the left common carotid artery (weighted mean difference, 0.12 mm; 95% CI, −0.05 to 0.28, P=0.176; I²=97.4%; P<0.001).

Conclusions

H. pylori infection is associated with increased carotid intima‐media thickness. Therefore, the infection may indirectly contribute to the development of major vascular events.

The effect of Helicobacter pylori eradication on C-reactive protein: results from a meta-analysis

INTRODUCTION

Helicobacter pylori is a bacterium that causes chronic gastroduodenal infection and affects various systemic diseases. An increase in the blood level of C-reactive protein (CRP; a systemic inflammatory marker), at a low-grade chronic inflammation level, is observed in cases of infection. However, the effect of H. pylori eradication on CRP remains undetermined. Therefore, we aimed to evaluate the circulating CRP levels in eradicated patients through a meta-analysis.

MATERIAL AND METHODS

The PubMed database was searched from its inception to June 2020. Studies that described the CRP levels following H. pylori eradication were collected. A random-effects meta-analysis was then performed using inverse variance with standardized mean difference.

RESULTS

A total of 10 eligible studies (642 subjects in total) were available. The median age in the studies was 49.9 years. The CRP level was 6.0 (median) mg/l before H. pylori eradication and 5.8 (median) mg/l after eradication. From the results of the overall meta-analysis, there was found to be a significant reduction in the CRP levels with H. pylori eradication (standardized mean difference: -0.64; 95% confidence interval: -1.02 to -0.27). The result was not similarly confirmed in a subanalysis of the available randomized controlled trials.

CONCLUSIONS

Weak evidence exists regarding the effects of H. pylori eradication on CRP levels. Further research is called for.

Antibiotics for secondary prevention of coronary heart disease

BACKGROUND

Coronary heart disease is the leading cause of mortality worldwide with approximately 7.4 million deaths each year. People with established coronary heart disease have a high risk of subsequent cardiovascular events including myocardial infarction, stroke, and cardiovascular death. Antibiotics might prevent such outcomes due to their antibacterial, antiinflammatory, and antioxidative effects. However, a randomised clinical trial and several observational studies have suggested that antibiotics may increase the risk of cardiovascular events and mortality. Furthermore, several non-Cochrane Reviews, that are now outdated, have assessed the effects of antibiotics for coronary heart disease and have shown conflicting results. No previous systematic review using Cochrane methodology has assessed the effects of antibiotics for coronary heart disease.

OBJECTIVES

We assessed the benefits and harms of antibiotics compared with placebo or no intervention for the secondary prevention of coronary heart disease.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS, SCI-EXPANDED, and BIOSIS in December 2019 in order to identify relevant trials. Additionally, we searched TRIP, Google Scholar, and nine trial registries in December 2019. We also contacted 11 pharmaceutical companies and searched the reference lists of included trials, previous systematic reviews, and other types of reviews.

SELECTION CRITERIA

Randomised clinical trials assessing the effects of antibiotics versus placebo or no intervention for secondary prevention of coronary heart disease in adult participants (≥18 years). Trials were included irrespective of setting, blinding, publication status, publication year, language, and reporting of our outcomes.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted data. Our primary outcomes were all-cause mortality, serious adverse event according to the International Conference on Harmonization - Good Clinical Practice (ICH-GCP), and quality of life. Our secondary outcomes were cardiovascular mortality, myocardial infarction, stroke, and sudden cardiac death. Our primary time point of interest was at maximum follow-up. Additionally, we extracted outcome data at 24±6 months follow-up. We assessed the risks of systematic errors using Cochrane 'Rosk of bias' tool. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes. We calculated absolute risk reduction (ARR) or increase (ARI) and number needed to treat for an additional beneficial outcome (NNTB) or for an additional harmful outcome (NNTH) if the outcome result showed a beneficial or harmful effect, respectively. The certainty of the body of evidence was assessed by GRADE.

MAIN RESULTS

We included 38 trials randomising a total of 26,638 participants (mean age 61.6 years), with 23/38 trials reporting data on 26,078 participants that could be meta-analysed. Three trials were at low risk of bias and the 35 remaining trials were at high risk of bias. Trials assessing the effects of macrolides (28 trials; 22,059 participants) and quinolones (two trials; 4162 participants) contributed with the vast majority of the data. Meta-analyses at maximum follow-up showed that antibiotics versus placebo or no intervention seemed to increase the risk of all-cause mortality (RR 1.06; 95% CI 0.99 to 1.13; P = 0.07; I² = 0%; ARI 0.48%; NNTH 208; 25,774 participants; 20 trials; high certainty of evidence), stroke (RR 1.14; 95% CI 1.00 to 1.29; P = 0.04; I² = 0%; ARI 0.73%; NNTH 138; 14,774 participants; 9 trials; high certainty of evidence), and probably also cardiovascular mortality (RR 1.11; 95% CI 0.98 to 1.25; P = 0.11; I²= 0%; 4674 participants; 2 trials; moderate certainty of evidence). Little to no difference was observed when assessing the risk of myocardial infarction (RR 0.95; 95% CI 0.88 to 1.03; P = 0.23; I² = 0%; 25,523 participants; 17 trials; high certainty of evidence). No evidence of a difference was observed when assessing sudden cardiac death (RR 1.08; 95% CI 0.90 to 1.31; P = 0.41; I² = 0%; 4520 participants; 2 trials; moderate certainty of evidence). Meta-analyses at 24±6 months follow-up showed that antibiotics versus placebo or no intervention increased the risk of all-cause mortality (RR 1.25; 95% CI 1.06 to 1.48; P = 0.007; I² = 0%; ARI 1.26%; NNTH 79 (95% CI 335 to 42); 9517 participants; 6 trials; high certainty of evidence), cardiovascular mortality (RR 1.50; 95% CI 1.17 to 1.91; P = 0.001; I² = 0%; ARI 1.12%; NNTH 89 (95% CI 261 to 49); 9044 participants; 5 trials; high certainty of evidence), and probably also sudden cardiac death (RR 1.77; 95% CI 1.28 to 2.44; P = 0.0005; I² = 0%; ARI 1.9%; NNTH 53 (95% CI 145 to 28); 4520 participants; 2 trials; moderate certainty of evidence). No evidence of a difference was observed when assessing the risk of myocardial infarction (RR 0.95; 95% CI 0.82 to 1.11; P = 0.53; I² = 43%; 9457 participants; 5 trials; moderate certainty of evidence) and stroke (RR 1.17; 95% CI 0.90 to 1.52; P = 0.24; I² = 0%; 9457 participants; 5 trials; high certainty of evidence). Meta-analyses of trials at low risk of bias differed from the overall analyses when assessing cardiovascular mortality at maximum follow-up. For all other outcomes, meta-analyses of trials at low risk of bias did not differ from the overall analyses. None of the trials specifically assessed serious adverse event according to ICH-GCP. No data were found on quality of life.

AUTHORS' CONCLUSIONS

Our present review indicates that antibiotics (macrolides or quinolones) for secondary prevention of coronary heart disease seem harmful when assessing the risk of all-cause mortality, cardiovascular mortality, and stroke at maximum follow-up and all-cause mortality, cardiovascular mortality, and sudden cardiac death at 24±6 months follow-up. Current evidence does, therefore, not support the clinical use of macrolides and quinolones for the secondary prevention of coronary heart disease. Future trials on the safety of macrolides or quinolones for the secondary prevention in patients with coronary heart disease do not seem ethical. In general, randomised clinical trials assessing the effects of antibiotics, especially macrolides and quinolones, need longer follow-up so that late-occurring adverse events can also be assessed.

Genetic Analyses of Common Infections in the Avon Longitudinal Study of Parents and Children Cohort

The burden of infections on an individual and public health is profound. Many observational studies have shown a link between infections and the pathogenesis of disease; however a greater understanding of the role of host genetics is essential. Children from the longitudinal birth cohort, the Avon Longitudinal Study of Parents and Children, had 14 antibodies measured in plasma at age 7: Alpha-casein protein, beta-casein protein, cytomegalovirus, Epstein-Barr virus, feline herpes virus, Helicobacter pylori, herpes simplex virus 1, influenza virus subtype H1N1, influenza virus subtype H3N2, measles virus, Saccharomyces cerevisiae, Theiler's virus, Toxoplasma gondii, and SAG1 protein domain, a surface antigen of Toxoplasma gondii measured for greater precision. We performed genome-wide association analyses of antibody levels against these 14 infections (N = 357 - 5010) and identified three genome-wide signals (P < 5×10^-8), two associated with measles virus antibodies and one with Toxoplasma gondii antibodies. In an association analysis focused on the human leukocyte antigen (HLA) region of the genome, we further detected 15 HLA alleles at a two-digit resolution and 23 HLA alleles at a four-digit resolution associated with five antibodies, with eight HLA alleles associated with Epstein-Barr virus antibodies showing strong evidence of replication in UK Biobank. We discuss how our findings from antibody levels complement other studies using self-reported phenotypes in understanding the architecture of host genetics related to infections.

Association between Helicobacter Pylori infection and stroke: a meta-analysis of 273,135 patients

BACKGROUND

Stroke stands among the most leading causes of mortality worldwide. Although modifiable risk factors for stroke have been identified, current risk factors do not sufficiently explain the risk in young patients. Previous studies have postulated an association between infection by Helicobacter pylori (HP) and stroke.

OBJECTIVE

To investigate the association between HP infection and stroke by using a systematic review and meta-analysis approach.

METHODS

Four electronic search engines/libraries were systematically searched for relevant observational studies. Studies were screened for eligibility and data were extracted. The odds ratio (OR) and 95% confidence interval (95% CI) were combined under the random-effect model. The protocol was registered in PROSPERO (CRD42019123689).

RESULTS

Among the included studies, 25 studies were analyzed for anti-HP IgG, 9 studies were for anti-Cag A, and 6 studies were for the C-urea breath test. The results showed that positive anti-HP IgG was significantly associated with an increased risk of stroke [OR (95% CI) = 1.43 (1.25-1.46)]. Similarly, both antiCag A and C-urea breath test were significantly associated with an increased risk of stroke with [OR (95% CI) = 1.77 (1.25-2.49)], and [OR (95% CI) = 2.21 (1.33-3.66)], respectively. Furthermore, our results indicated that positive anti-HP IgG was associated with stroke caused by atherothrombosis and small artery disease.

CONCLUSIONS

This study suggests that HP infection is significantly associated with increased risk of stroke. However, more well-designed studies are required to investigate if early HP eradication might decrease the incidence of stroke.

Effect of Helicobacter pylori infection on the risk of acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

Numerous studies have illustrated the association between Helicobacter pylori (H pylori) infection and acute coronary syndrome (ACS). However, the results are contradictory. Therefore, we conducted the meta-analysis to identify the association between H pylori and ACS.

METHODS

We performed a systematic search through electronic databases (Excerpta Medica Database, PubMed, Cochrane Library, and Web of Science). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random effect model. We also carried out the sensitivity analysis and publication bias.

RESULTS

Forty-four eligible studies involving 7522 cases and 8311 controls were included. The pooled result showed that H pylori infection was associated with an increase risk of ACS (OR = 2.03, 95% CI 1.66-2.47). In addition, similar results were obtained in subgroups of study quality, area, human development index, and H pylori detection method. The OR for developing countries was significantly higher than developed countries (OR = 2.58 vs OR = 1.69). Moreover, H pylori with cytotoxin-associated antigen A was also significantly associated with an increase risk of ACS (OR = 2.39, 95% CI 1.21-4.74).

CONCLUSION

The meta-analysis suggested that H pylori infection was associated with an increased risk of ACS, especially in developing countries. H pylori is easily screened and can be treated with a wide range of drugs. Thus, more high-quality and well-designed studies are needed to confirm whether the treatment of H pylori is an effective way to reduce ACS risk.

H. pylori infection and extra-gastroduodenal diseases

Helicobacter pylori infection is the principal cause of peptic ulcer disease, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue lymphoma. Recent studies have shown that it may interfere with many biological processes and determine or influence the occurrence of many diseases outside the stomach. Currently, the role of H. pylori in idiopathic thrombocytopenic purpura and iron deficiency anemia is well documented. Emerging evidence suggests that it may also contribute to vitamin B12 deficiency, insulin resistance, metabolic syndrome, diabetes mellitus and non-alcoholic liver disease. Additionally, it may increase the risk of acute coronary syndrome, cerebrovascular disease, neurodegenerative disease and other miscellaneous disorders. Different pathogenic mechanisms have been hypothesized, including the occurrence of molecular mimicry and the induction of a low-grade inflammation. This review summarizes the results of the most relevant studies on the extra-gastroduodenal manifestations of H. pylori infection.

Helicobacter pylori and cardiovascular complications: a mechanism based review on role of Helicobacter pylori in cardiovascular diseases

Heart disease comprises a wide class of cardiovascular abnormalities, including ischemic heart disease, myocardial infarction, atherosclerosis, and coronary artery disease. It is the leading cause of death all over the world. Several traditional and novel risk factors, such as infectious and noninfectious agents, have been associated with heart disease. Out of these, Helicobacter pylori has been recently introduced as an important etiological factor for heart disease. Numerous seroepidemiological findings observed H. pylori antibodies in the blood of a patient with cardiovascular complications. The bacteria survive in the epithelial cells of gastric organs and cause digestive complications. Excess inflammatory pathogenesis and prognosis stimulate an immune response that further causes significant disturbances in various factors like cytokines, fibrinogen, triglycerides, high density lipoprotein, C-reactive protein, heat shock protein, and white blood cell count, and provoke a number of problems such as atherosclerosis and prothrombic state, and cross-reactivity which eventually leads to heart diseases. H. pylori releases toxigenic nutrients, chiefly vacuolating cytotoxin gen A (Vac A) and cytotoxin associated gene A (Cag A), of which Cag A is more virulent and involved in the formation of cholesterol patches in arteries, induction of autoimmune disorder, and release of immune mediated response. Although numerous mechanisms have been correlated with H. pylori and heart disease, the exact role of bacteria is still ambiguous.

Association between Helicobacter pylori Infection and Cerebral Small Vessel Disease

Background

Small vessel disease is an important cause of cerebrovascular diseases and cognitive impairment in the elderly. There have been conflicting results regarding the relationship between Helicobacter pylori infection and ischemic stroke. This study aimed to examine the association between H. pylori infection and cerebral small vessel disease.

Methods

The study included 1,117 patients who underwent brain magnetic resonance imaging and H. pylori identification between 2005 and 2013 at Health Promotion Center, Seoul National University Hospital. Multivariable logistic regression analysis was used to assess the association between H. pylori infection and small vessel disease with adjustment for age, sex, hypertension, diabetes mellitus, dyslipidemia, body mass index, smoking status, problem drinking, and antiplatelet use.

Results

The adjusted odds ratios (aORs) for the association between H. pylori infection and silent brain infarction and cerebral microbleeds were 1.03 (95% confidence interval [CI], 0.66-1.61) and 0.70 (95% CI, 0.38-1.28), respectively. The aORs for silent brain infarction and cerebral microbleeds were 0.81 (95% CI, 0.44-1.44) and 0.59 (95% CI, 0.30-1.18) in patients aged <65 years and 1.59 (95% CI, 0.78-3.22) and 1.89 (95% CI, 0.38-9.33) in those aged >65 years, respectively. Moreover, the aORs for silent brain infarction and cerebral microbleeds were 0.96 (95% CI, 0.54-1.71) and 0.74 (95% CI, 0.33-1.69) in H. pylori-infected patients without atrophic gastritis and 0.89 (95% CI, 0.48-1.62) and 0.99 (95% CI, 0.43-2.27) in those with atrophic gastritis, respectively.

Conclusion

No association between H. pylori infection and small vessel disease was observed. H. pylori-induced inflammation may not be a risk factor for microcirculatory damage in the brain.

Association between Helicobacter pylori infection and stroke: a meta-analysis of prospective observational studies

BACKGROUND

Some studies have suggested an association between Helicobacter pylori infection and the risk of stroke, but the relationship remains controversial. The aim of this study was to obtain a more comprehensive estimate of H. pylori on the risk of stroke by performing a meta-analysis.

METHODS

A computerized search of PubMed, EMBASE, and the Cochrane library (including CENTRAL) up to February 2014 was performed to identify eligible studies. Prospective studies reported that a multivariate-adjusted estimate for the association between H. pylori and stroke were included. A random-effects model was used to calculate the overall combined risk.

RESULTS

Ten prospective observational studies (6 cohort studies, 4 nested case-control, or case-cohort studies within cohort studies) were included in the meta-analysis. The overall combined odds ratio for H. infection and stroke was .96 (95% confidence interval, .78-1.14). Similar results were yielded in patients with cytotoxin-associated gene-A seropositive strains. The combined estimates were robust across sensitivity analyses and had no observed publication bias.

CONCLUSIONS

In conclusion, our formal meta-analysis indicated no strong association between H. pylori infection and stroke, neither in those with cytotoxin-associated gene-A-positive infection. We believe that future epidemiologic studies of H. pylori and stroke are unlikely to be fruitful.

Helicobacter pylori Infection Increase the Risk of Myocardial Infarction: A Meta-Analysis of 26 Studies Involving more than 20,000 Participants

BACKGROUND

Myocardial infarction is a fatal cardiovascular disease and one of the most common death causes all around the world. The aim of the meta-analysis was to quantify the risk of myocardial infarction associated with Helicobacter pylori infection.

METHODS

A literature search was performed to identify studies published before 14 July, 2014, for relevant risk estimates. Fixed and random effect meta-analytical techniques were conducted for myocardial infarction.

RESULTS

Twenty-six case-control studies involving 5829 myocardial infarction patients and more than 16,000 controls were included. Helicobacter pylori infection was associated with an increased risk of myocardial infarction (OR: 2.10, 95%CI: 1.75-2.53, p = .06). We also discovered a significant association between the bacteria and risk of myocardial infarction in young people (OR: 1.93, 95% CI: 1.41-2.66, p = .07), in elder people (OR: 2.02, 95% CI: 1.60-2.54, p = .29), in Caucasians (OR: 2.29, 95% CI: 1.99-2.63, p = .12), and in Asians (OR: 1.75, 95% CI: 1.12-2.73, p = .08).

CONCLUSION

Our meta-analyses suggested a possible indication of relationship between Helicobacter pylori infection and the risk of myocardial infarction. The pathogenicity might not be affected by age and race. More researches should be conducted to explore the mechanisms involved.

Role of Helicobacter pylori infection in pathogenesis of atherosclerosis

Though a century old hypothesis, infection as a cause for atherosclerosis is still a debatable issue. Epidemiological and clinical studies had shown a possible association but inhomogeneity in the study population and study methods along with potential confounders have yielded conflicting results. Infection triggers a chronic inflammatory state which along with other mechanisms such as dyslipidemia, hyper-homocysteinemia, hypercoagulability, impaired glucose metabolism and endothelial dysfunction, contribute in pathogenesis of atherosclerosis. Studies have shown a positive relations between Cytotoxic associated gene-A positive strains of Helicobacter pylori and vascular diseases such as coronary artery disease and stroke. Infection mediated genetic modulation is a new emerging theory in this regard. Further large scale studies on infection and atherosclerosis focusing on multiple pathogenetic mechanisms may help in refining our knowledge in this aspect.

Association between Bacterial Infection and Peripheral Vascular Disease: A Review

There are an increasing number of data showing a clinically important association between bacterial infection and peripheral artery disease (PAD). Bacteria suspected of being involved in PAD pathogenesis are: periodontal bacteria, gut microbiota, Helicobacter pylori, and Chlamydia pneumoniae. Infectious agents may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local host immunological response to contamination of extravascular tissues or the vascular wall, respectively. A systemic immunological reaction may damage vascular walls in the course of autoimmunological cross-reactions between anti-pathogen antibodies and host vascular antigens (immunological mimicry), pathogen burden mechanisms (nonspecific activation of inflammatory processes in the vascular wall), and neuroendocrine-immune cross-talk. Besides activating the inflammatory pathway, bacterial infection may trigger PAD progression or exacerbation by enhancement of platelet reactivity, by a stimulatory effect on von Willebrand factor binding, factor VIII, fibrinogen, P-selectin activation, disturbances in plasma lipids, increase in oxidative stress, and resistance to insulin. Local inflammatory host reaction and induction of atherosclerotic plaque progression and/or instability result mainly from atherosclerotic plaque colonization by microorganisms. Despite these premises, the role of bacterial infection in PAD pathogenesis should still be recognized as controversial, and randomized, controlled trials are required to evaluate the outcome of periodontal or gut bacteria modification (through diet, prebiotics, and probiotics) or eradication (using antibiotics) in hard and surrogate cardiovascular endpoints.

Extraintestinal manifestations of Helicobacter pylori: A concise review

Helicobacter pylori (H. pylori) infection has been clearly linked to peptic ulcer disease and some gastrointestinal malignancies. Increasing evidence demonstrates possible associations to disease states in other organ systems, known as the extraintestinal manifestations of H. pylori. Different conditions associated with H. pylori infection include those from hematologic, cardiopulmonary, metabolic, neurologic, and dermatologic systems. The aim of this article is to provide a concise review of the evidence that supports or refutes the associations of H. pylori and its proposed extraintestinal manifestations. Based on data from the literature, PUD, mucosal associated lymphoid tumors lymphoma, and gastric adenocarcinoma has well-established links. Current evidence most supports extraintestinal manifestations with H. pylori in immune thrombocytopenic purpura, iron deficiency anemia, urticaria, Parkinson’s, migraines and rosacea; however, there is still plausible link with other diseases that requires further research.

Helicobacter pylori infection and the risk of acute coronary syndrome: a nationwide retrospective cohort study

Helicobacter pylori infection (HPI) imposes substantial social costs and is of major etiological importance in peptic ulcer disease, gastric cancer, and accelerated cardiovascular diseases. This study determined the risk of acute coronary syndrome (ACS) associated with HPI in a nationwide retrospective cohort study. By using the Taiwan National Health Insurance Research Database (NHIRD), we identified patients diagnosed with HPI from 1998 to 2010. In addition, we randomly selected non-HPI controls frequency-matched by age, sex, and index year from the general population free of HPI. The risk of ACS was analyzed using Cox proportional hazards regression models in which sex, age, and comorbidities were included as variables. We identified 17,075 participants for the HPI group and selected 68,300 participants for the comparison group. The incidence rates were increased in the patients in the HPI group compared with those in the comparison group. Overall, the HPI patients exhibited a 1.93-fold high crude hazard ratio for ACS, and a 1.48-fold adjusted hazard ratio after age, sex, and comorbidities were adjusted. However, the overall adjusted hazard ratio of ACS increased with increasing age with a 3.11 to 8.24 adjusted hazard ratio among the various age groups. Several comorbidities, such as diabetes, hyperlipidemia, and COPD exhibited synergistic effects for ACS risk. We determined a significant association between ACS and comorbidities and provide evidence to encourage clinicians to observe ACS-related comorbidities.

Clinical significance of Helicobacter pylori infection in patients with acute coronary syndromes: an overview of current evidence

Although Helicobacter pylori (Hp) primarily colonizes gastric mucosa, it can occasionally inhabit in atherosclerotic plaques. Both forms of Hp infection may be involved in the pathogenesis of atherosclerosis via activation of a systemic or local inflammatory host reaction and induction of plaque progression and/or instability, possibly leading to coronary syndromes. The association between Hp infection and cardiovascular endpoint prevalence remains uncertain; however, it has been reported in many epidemiological investigations and may be reasonably explained by pathophysiological mechanisms. Besides the inflammatory pathway, Hp infection may trigger acute coronary syndromes by enhanced platelet reactivity and increased risk of gastrointestinal bleeding (type 2 myocardial infarction). The former seems to be predominantly related to the stimulatory effect of Hp infection on von Willebrand factor-binding and P-selectin activation, and the latter results from cytotoxic bacteria properties and aggravation of digestive tract injury related to aspirin or dual antiplatelet therapy. Despite these premises, the role of Hp infection in cardiovascular syndromes should still be recognized as controversial and requiring randomized, controlled trials to evaluate the outcome of Hp eradication in both cardiac and gastroenterological endpoints. Such need is also justified by potential bias of previous studies resulting from (1) using different diagnostic methods for identification of Hp infection, since only a small number of studies required confirmation of active Hp infection; and from (2) common lack of adjustment for important confounders such as socioeconomic status, smoking and effectiveness of eradication therapy, as well as the genetic characteristics of both the host and the bacterium.

Acute infection contributes to racial disparities in stroke mortality

OBJECTIVE

It is unknown whether racial differences in exposure to acute precipitants of stroke, specifically infection, contribute to racial disparities in stroke mortality.

METHODS

Among participants in the nationally representative Health and Retirement Study with linked Medicare data (1991-2007), we conducted a case-crossover study employing within-person comparisons to study racial/ethnic differences in the risks of death and hospitalization from ischemic stroke following acute infection.

RESULTS

There were 964 adults hospitalized for ischemic stroke. Acute infection increased the 30-day risks of ischemic stroke death (5.82-fold) and ischemic stroke hospitalization (1.87-fold). Acute infection was a more potent trigger of acute ischemic stroke death in non-Hispanic blacks (odds ratio [OR] 39.21; 95% confidence interval [CI] 9.26-166.00) than in non-Hispanic whites (OR 4.50; 95% CI 3.14-6.44) or Hispanics (OR 5.18; 95% CI 1.34-19.95) (race-by-stroke interaction, p = 0.005). When adjusted for atrial fibrillation, infection remained more strongly associated with stroke mortality in blacks (OR 34.85) than in whites (OR 3.58) and Hispanics (OR 3.53). Acute infection increased the short-term risk of incident stroke similarly across racial/ethnic groups. Infection occurred often before stroke death in non-Hispanic blacks, with 70% experiencing an infection in the 30 days before stroke death compared to a background frequency of 15%.

CONCLUSIONS

Acute infection disproportionately increases the risk of stroke death for non-Hispanic blacks, independently of atrial fibrillation. Stroke incidence did not explain this finding. Acute infection appears to be one factor that contributes to the black-white disparity in stroke mortality.

Antibody levels to persistent pathogens and incident stroke in Mexican Americans

Background

Persistent pathogens have been proposed as risk factors for stroke; however, the evidence remains inconclusive. Mexican Americans have an increased risk of stroke especially at younger ages, as well as a higher prevalence of infections caused by several persistent pathogens.

Methodology/Principal

Findings Using data from the Sacramento Area Latino Study on Aging (n = 1621), the authors used discrete-time regression to examine associations between stroke risk and (1) immunoglobulin G antibody levels to Helicobacter pylori (H. pylori), Cytomegalovirus, Varicella Zoster Virus, Toxoplasma gondii and Herpes simplex virus 1, and (2) concurrent exposure to several pathogens (pathogen burden), defined as: (a) summed sero-positivity, (b) number of pathogens eliciting high antibody levels, and (c) average antibody level. Models were adjusted for socio-demographics and stroke risk factors. Antibody levels to H. pylori predicted incident stroke in fully adjusted models (Odds Ratio: 1.58; 95% Confidence Interval: 1.09, 2.28). No significant associations were found between stroke risk and antibody levels to the other four pathogens. No associations were found for pathogen burden and incident stroke in fully adjusted models.

Conclusions/Significance

Our results suggest that exposure to H. pylori may be a stroke risk factor in Mexican Americans and may contribute to ethnic differences in stroke risk given the increased prevalence of exposure to H. pylori in this population. Future studies are needed to confirm this association.

Crystal structure and mode of helicase binding of the C-terminal domain of primase from Helicobacter pylori

To better understand the poor conservation of the helicase binding domain of primases (DnaGs) among the eubacteria, we determined the crystal structure of the Helicobacter pylori DnaG C-terminal domain (HpDnaG-CTD) at 1.78 Å. The structure has a globular subdomain connected to a helical hairpin. Structural comparison has revealed that globular subdomains, despite the variation in number of helices, have broadly similar arrangements across the species, whereas helical hairpins show different orientations. Further, to study the helicase-primase interaction in H. pylori, a complex was modeled using the HpDnaG-CTD and HpDnaB-NTD (helicase) crystal structures using the Bacillus stearothermophilus BstDnaB-BstDnaG-CTD (helicase-primase) complex structure as a template. By using this model, a nonconserved critical residue Phe534 on helicase binding interface of DnaG-CTD was identified. Mutation guided by molecular dynamics, biophysical, and biochemical studies validated our model. We further concluded that species-specific helicase-primase interactions are influenced by electrostatic surface potentials apart from the critical hydrophobic surface residues.

Prognostic role of Helicobacter pylori infection in acute coronary syndrome: a prospective cohort study

Abstract

In a prospective cohort study, we evaluated the effect of Helicobacter pylori seropositivity on the risk of future adverse cardiovascular outcomes among patients with acute coronary syndrome (ACS). In 433 patients, IgA and IgG antibodies to H pylori, along with classic risk factors, including hypertension, diabetes, hyperlipidaemia, smoking and family history of coronary artery disease (CAD) were determined. Short-and long-term follow-up information on adverse outcomes, defined as recurrence of unstable angina, myocardial infarction, coronary angioplasty, coronary artery bypass graft surgery, and sudden cardiac death was obtained. None of the classic CAD risk factors correlated with incidence of either short- or long-term outcomes. Seropositivity for H pylori was significantly associated with risk of short-term adverse outcomes, and independently predicted their incidence in multivariate regression (R = 3.05, p < 0.001). Results failed to show such an association between H pylori seropositivity and long-term adverse outcomes. H pylori infection may affect short-term prognosis in patients with ACS. Randomised trials are needed to evaluate the role of H pylori eradication in these patients.

The effect of the treatment of Helicobacter pylori infection on the glycemic control in type 2 diabetes mellitus

AIM

To evaluate the possible long-term effects of Helicobacter pylori infection on Hemoglobin A1c and fasting blood sugar levels in patients with type 2 diabetes.

BACKGROUND

Helicobacter pylori causes the gastrointestinal tract inflammation, which it plays an important role in distortion of glucose and lipids absorption that altered lipid metabolism and energy harvesting and develops type 2 diabetes, insulin resistance and has been linked to impaired blood glucose.

PATIENTS AND METHODS

In this clinical trial, patients with type 2 diabetes and confirmed Helicobacter pylori infection were recruited from the endocrinology clinic of the Shahid Beheshti University Tehran, Iran. Before and after 3 months of eradication therapy fasting blood samples were taken and glycalated hemoglobin levels and fasting blood sugar levels were measured.

RESULTS

85 (27 male 31.8%, 58 female 68.2%) patients with the mean age of 52.±4.7 years were recruited. 52 (62%) had successful Helicobacter pylori eradication (16 male, 30.8% and 36 female, 69.2%). The mean glycalated haemoglobin levels before successful treatment was 8.7±1.1 and after treatment was 8.3±0.9 and difference was significant (p<0.001). Mean IgG level of serology was 3.3±1.1 and the correlation with glycalated haemoglobin was significant (p=0.02) (r=0.4).

CONCLUSION

Our results indicate that the Helicobacter pylori treatment can improve the mean glycalated haemoglobin in patients with type 2 diabetes. More investigations will be required to evaluate the effects of Helicobacter pylori eradication among different age groups and in relation to obesity status, diabetes and other disease, and it may be beneficial for patients at risk of diabetes to be checked for the presence of Helicobacter pylori infection.

Chronic Helicobacter pylori infection and ischemic stroke subtypes

OBJECTIVE

Chronic infection by Helicobacter pylori is regarded as an etiological factor for vascular diseases. However, there are conflicting results on the relevance of chronic infection by Helicobacter pylori as a risk factor for ischemic stroke. The aim of our study was to investigate the association between Helicobacter pylori infection and ischemic stroke subtypes in Chinese.

METHOD

A total of 150 patients with ischemic stroke were enrolled in the patient group. Analyses were stratified for etiologic stroke subtypes according to 2007 modified Trial of Org 10172 in Acute Stroke Treatment criteria: 119 patients with atherothrombosis, 15 patients with cardioembolism, and 12 patients with small artery disease. One hundred and thirty-one control subjects without clinical and instrumental evidence of atherosclerotic diseases were randomly selected from health check-up center. The potential risk factors for Helicobacter pylori infection and traditional risk factors for ischemic stroke of all subjects were analyzed. The serum specific antibody IgG of Helicobacter pylori was detected by enzyme-linked immunosorbent assay. Conditional logistic regression was used to analyze the data.

RESULTS

The Helicobacter pylori/IgG-positive rate in the patient group was higher than that in the healthy control group, but the difference was not statistically significant [67.3% versus 61.8%; odds ratio (OR) = 1.272; P = 0.336]. This result remained non-significant after adjustment for other established risk factors [OR = 1.222; 95% confidence interval (CI): 0.688-2.171; P = 0.494]. Subgroup analysis using univariate and multivariate analyses yielded similar results in all etiologic stroke subtypes (univariate analysis, atherothrombosis: OR = 1.368, 95%CI: 0.810-2.311, P = 0.241; cardioembolism: OR = 0.926, 95%CI:0.311-2.758, P = 0.890; small artery disease: OR = 1.852, 95%CI: 0.478-7.167, P = 0.366; multivariate analysis, atherothrombosis: OR = 1.385, 95%CI: 0.726-2.639, P = 0.323; cardioembolism: OR = 0.832, 95%CI: 0.236-2.932, P = 0.775; small artery disease: OR = 1.836, 95%CI: 0.396-8.503, P = 0.437).

CONCLUSIONS

This case-control study does not reveal any strong association between chronic Helicobacter pylori infection and ischemic stroke. Large case-control prospective studies are required for further investigation of the potential association between Helicobacter pylori infection and ischemic stroke risk, particularly in certain subgroups.

Absence ofHelicobacter pyloriin healthy laryngeal mucosa

Objectives:

To evaluate the presence ofHelicobacter pyloriin healthy laryngeal mucosa.

Design:

Prospective analysis ofHelicobacter pyloricolonisation in healthy laryngeal mucosa, using the13C urea breath test and polymerase chain reaction analysis.

Subjects:

Twenty randomly chosen men (28–78 years) without laryngeal pathology or gastrointestinal disease were investigated. All subjects were scheduled for elective operative procedures, under general, endotracheal anaesthesia. Cytobrush samples were taken forHelicobacter pyloriDNA detection. Nested polymerase chain reaction testing was performed on DNA solutions using two primer pairs from the urease A gene of theHelicobacter pylorigenome. The13C urea breath test was performed on two exhalation samples.

Results:

Eight (40 per cent) of the subjects were positive for urease on urea breath testing; none were positive forHelicobacter pyloriDNA on polymerase chain reaction testing.

Conclusion:

Based on these results, we do not considerHelicobacter pylorito be a normal constituent of healthy laryngeal microflora.

Infectious burden and risk of stroke: the northern Manhattan study

OBJECTIVE

To determine the association between a composite measure of serological test results for common infections (Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, and herpes simplex virus 1 and 2) and stroke risk in a prospective cohort study.

DESIGN

Prospective cohort followed up longitudinally for median 8 years.

SETTING

Northern Manhattan Study. Patients Randomly selected stroke-free participants from a multiethnic urban community. Main Outcome Measure Incident stroke and other vascular events.

RESULTS

All 5 infectious serological results were available from baseline samples in 1625 participants (mean [SD] age, 68.4 [10.1] years; 64.9% women). Cox proportional hazards models were used to estimate associations of each positive serological test result with stroke. Individual parameter estimates were then combined into a weighted index of infectious burden and used to calculate hazard ratios and confidence intervals for association with risk of stroke and other outcomes, adjusted for risk factors. Each individual infection was positively, though not significantly, associated with stroke risk after adjusting for other risk factors. The infectious burden index was associated with an increased risk of all strokes (adjusted hazard ratio per standard deviation, 1.39; 95% confidence interval, 1.02-1.90) after adjusting for demographics and risk factors. Results were similar after excluding those with coronary disease (adjusted hazard ratio, 1.50; 95% confidence interval, 1.05-2.13) and adjusting for inflammatory biomarkers.

CONCLUSIONS

A quantitative weighted index of infectious burden was associated with risk of first stroke in this cohort. Future studies are needed to confirm these findings and to further define optimal measures of infectious burden as a stroke risk factor.

Possible association of atrophic gastritis and arterial stiffness in healthy middle-aged Japanese

AIM

Helicobacter pylori (HP) has been implicated as a risk factor for cardiovascular and atherosclerotic diseases. Arterial stiffness determined by pulse wave velocity (PWV) or the cardio-ankle vascular index (CAVI) has been shown to be higher in HP-positive subjects than in HP-negative subjects; however, this result has been observed only in young subjects. The aim of the study was to investigate the possible correlation between HP infection and PWV or CAVI in middle-aged subjects.

METHODS

We measured brachial-ankle PWV (baPWV), CAVI, metabolism markers, pepsinogens (PGs) and IgG antibody to HP in 343 individuals aged either 60 or 65 year old. Atrophic gastritis (AG) was diagnosed based on the values of PGs.

RESULTS

baPWV and CAVI were significantly higher in the AG-positive group than in the AG-negative group even after adjusting for possible confounding factors (baPWVc; 16.63+/-3.50 vs. 15.59+/-3.47 p=0.010, CAVIc; 8.59+/-1.20 vs. 8.27+/-1.19 p=0.022). baPWV and CAVI values tended to be higher in the HP-positive group than in the HP-negative group. High-density lipoprotein (HDL) cholesterol level and the adiponectin level were lower in the AG-positive group than in the AG-negative group.

CONCLUSION

There may be an association between atrophic gastritis and atherosclerosis in middle-aged subjects.

Chronic infection in the etiology of atherosclerosis--the case for Chlamydia pneumoniae

Established cardiovascular risk factors do not fully explain the variations in the prevalence and severity of coronary heart disease. Recent evidence suggests that common chronic infections may contribute, either by direct or indirect mechanisms, to the etiology and/or progression of coronary atherosclerosis. Of the candidate infectious agents implicated, Chlamydia pneumoniae has emerged as the most likely pathogen to have a causal role. Evidence for this is based on seroepidemiologic, pathologic, and laboratory-based evidence, in addition to recent small-scale antibiotic intervention studies. Concerted efforts are now focused on the design of large prospective trials with antibiotics active against C. pneumoniae in the secondary prevention of coronary heart disease.

Helicobacter pylori infection does not accelerate the age-related progression of arteriosclerosis: a 4-year follow-up study

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) infection has been reported to correlate with the onset of cardiovascular diseases. However, the relationship between H. pylori infection and the progression of arteriosclerosis has not been fully investigated. The aim of this study was to clarify the possible role of H. pylori infection in the development of arteriosclerosis.

METHODS

Study subjects were 258 cases who attended their annual medical check-ups and were twice investigated by the parameters of arteriosclerosis at a 4-year interval. Arteriosclerotic parameters (systolic blood pressure [SBP]), ankle brachial index [ABI], and pulse wave velocity [PWV]) were measured non-invasively using an automatic device. H. pylori-infection status was determined by assaying serum anti-H. pylori IgG antibodies. The changes in the arteriosclerotic parameters during the 4 years were compared between H. pylori-seropositive and seronegative individuals.

RESULTS

A total of 166 subjects (64.3%) were H. pylori-seropositive. After adjustment for gender, age, body mass index, and smoking and drinking habits, there were no differences in any of the arteriosclerotic parameters between the groups, not only at enrollment but after the 4 years, although the high-density lipoprotein cholesterol levels of the seropositive groups were significantly lower than those of seronegative groups. SBP and PWVs were significantly increased during 4 years in both the seropositive and seronegative groups. The percentage of changes in SBP and PWVs, which were calculated by ([values after 4 years--values at enrollment/values at enrollment] x 100), did not differ between the groups.

CONCLUSION

H. pylori infection does not accelerate the age-related progression of arteriosclerosis in Japanese individuals.

High prevalence of Cag-A positive H. pylori strains in ischemic stroke: a primary care multicenter study

BACKGROUND

Previous studies suggested an association between CagA-positive H. pylori strains and ischemic stroke. The aim of the present study was to assess the prevalence of Helicobacter pylori infection and CagA status in patients with atherosclerotic stroke in the primary care setting.

MATERIALS AND METHODS

A total of 106 consecutive patients (age 76.6 +/- 8 years; males 52%) with well-documented history of atherosclerotic stroke and 106 sex-age- (age 76.5 +/- 9 years; males 52%) and social background-matched controls without relevant vascular diseases. Risk factors for ischemic stroke were recorded in all subjects. H. pylori infection was assessed by[13]C-urea breath test. A serologic assay for specific IgG against CagA was performed in infected subjects.

RESULTS

A trend toward a higher prevalence of H. pylori was observed in cases (63%) with respect to controls (54%) without reaching a statistical significance. CagA positivity was associated to a higher risk of atherosclerotic stroke (adjusted odds ratio 2.69, 95% confidence interval 1.37-5.30).

CONCLUSIONS

Our findings suggest that CagA-positive strains of H. pylori are significantly associated to atherosclerotic stroke. This is not a merely confirmative study since it has been performed for the first time in the primary care setting and included only subjects with an active infection.

Pathogen burden in essential hypertension

BACKGROUND

Associations between pathogens and hypertension (HT) has been reported, but few studies have focused on the relationship between aggregate pathogens and HT. The present study explored whether the risk of HT is associated with each pathogen (defined as Chlamydia pneumoniae (C. pneumoniaee), mycoplasma pneumoniae (m. pneumoniae), helicobacter pylori (h. pylori) and coxsackie virus) or with aggregate pathogens in chinese mongolians.

METHODS AND RESULTS

One thousand and thirty Chinese Mongolians aged 30 years or more were recruited, including 488 hypertensive and 942 normotensive subjects. Enzyme-linked immunosorbent assay was used to detect IgG antibodies for C. pneumoniaee, M. pneumoniae, H. pylori and Coxsackie virus. The seroprevalence of Coxsackie virus was significantly associated with HT (odds ratio (OR) 3.7 after adjustment for risk factors), but no significant association was found for C. pneumoniae, M. pneumoniae and H. pylori (OR 1.32, 0.75 and 1.19, respectively). The results also showed that the risk of HT was associated with the aggregate pathogens: it increased with the increasing number of pathogens, and the ORs were 1.629, 2.653, 2.129, and 5.146 for 1, 2, 3 and 4 pathogens, respectively, after controlling for risk factors.

CONCLUSION

The risk of HT is associated with Coxsackie virus and aggregate pathogen load. The mechanism(s) underlying the associations remain to be elucidated further.

The association between current Helicobacter pylori infection and coronary artery disease

BACKGROUND

The role of Helicobacter pylori (H. pylori) in the pathogenesis of coronary artery disease (CAD) is still controversial, and the relation between current H. pylori infection and CAD has not been fully examined. This study evaluated the relation between H. pylori infection as confirmed by gastroduodenoscopic biopsy and CAD.

METHODS

We determined the presence of H. pylori infections, via gastroduodenoscopy, in 88 patients of the normal coronary angiographic group and also in 175 patients of the CAD group, and the latter patients had more than 50% coronary stenosis angiographically demonstrated. We excluded those patients with a history of previous H. pylori eradication and/or malignancy. A small piece of tissue from the antrum, which was obtained by gastroduodenoscopic biopsy, was stained by Warthin-starry silver stain. We defined a negative staining result that there was no stained tissue in the sample and the stained tissue was also positive for H. pylori infection.

RESULTS

There was no significant difference, except for gender, age, smoking and high density lipoprotein cholesterol (HDL-c), of the demographic and laboratory characteristics between the groups. Twenty seven (30.7%) patients of the normal control group and 71 (40.6%) patients of the CAD group were positive of H. pylori infection, yet there was no statistical difference. We angiographically followed up the 80 patients of the CAD group who were treated by percutaneous coronary intervention (PCI) at 6 to 9 months after their primary intervention. Twenty two (37.9%) of the 58 patients of the H. pylori negative group and 10 (45.5%) of the 22 patients of the H. pylori positive group were treated with reintervention, but reintervention was also not significantly different between the group with H. pylori infection and the group without the infection.

CONCLUSIONS

These data indicated that H. pylori infection had a modest influence on CAD and progressive atheroma, but the showed a tendency to increase. Further studies are needed to evaluate the relationship between H. pylori infection and CAD.

Elevated homocysteine levels in patients with slow coronary flow: relationship with Helicobacter pylori infection

BACKGROUND AND OBJECTIVE

Elevation of plasma homocysteine (Hcy) level has been implicated in the pathogenesis of slow coronary flow (SCF) as it can severely disturb vascular endothelial function. Helicobacter pylori chronically infect the human stomach and causes malabsorption of vitamin B(12) and folate in food, leading ultimately to an increase in circulating Hcy levels.

METHODS

Forty-three patients with angiographically proven SCF (group I) were enrolled in this study; 43 cases with normal coronary flow pattern (group II) served as controls. Fasting plasma levels of Hcy, vitamin B(12), and folate were measured in all subjects. Presence of H. pylori infection was defined as positive 14 C urea breath test. Coronary flow patterns for each major epicardial coronary artery were determined with the Thrombolysis in Myocardial Infarction (TIMI) frame count method.

RESULTS

Mean TIMI frame count was 46.3 +/- 8.7 in group I and 24.3 +/- 2.9 in Group II (p = .0001). Vitamin B(12) levels were similar, whereas folate levels were dramatically reduced in group I compared to group II (13.2 +/- 4.3 vs. 17.1 +/- 5.2, p = .0001). Plasma Hcy levels were significantly higher in group I compared to group II (13.4 +/- 5.6 vs. 7.9 +/- 2.5, p = .0001) as was the prevalence of H. pylori infection (90.7% in group I vs. 58.1% in group II, p = .001). Hcy levels were elevated (11.7 +/- 5.3 vs. 7.5 +/- 2.7, p = .0001) and folate levels were reduced (13.9 +/- 4.7 vs. 18.6 +/- 4.9, p = .0001) in patients with H. pylori infection, while vitamin B(12) levels were similar in patients with and without H. pylori infection. Correlation analysis revealed a significant negative correlation between plasma folate and Hcy levels and also between folate levels and mean TIMI frame counts (r = -.33, p = .002 vs. r = -.33, p = .003). Moreover, there was a significant positive correlation between plasma Hcy levels and mean TIMI frame counts (r = .66, p = .0001). In addition, the folate level was the only significant determinant of the variance of Hcy in multiple regression analysis (r = -.21, p = .03).

CONCLUSION

Our data showed that plasma folate levels were decreased and plasma Hcy levels were increased in patients with SCF compared to controls. Also, the prevalence of H. pylori infection was increased in patients with SCF. These findings suggest that elevated levels of plasma Hcy, possibly caused by H. pylori infection, and/or a possible disturbance in its metabolism may play a role in the pathogenesis of SCF.

Helicobacter pylori in Bronchiectasis: A Polymerase Chain Reaction Assay in Bronchoalveolar Lavage Fluid and Bronchiectatic Lung Tissue

BACKGROUND

A number of studies have implicated an association between H. pylori and diverse extra-gastroduodenal pathologies. Chronic inflammation and increased immune response have been observed in bronchiectasis, likely gastroduodenal inflammatory diseases. H. pylori has been found in the trachea-bronchial aspirates of mechanically ventilated patients. Furthermore, the seroprevalence of H. pylori was found to be significantly higher in patients with bronchiectasis than in the control group. The present study was performed to investigate the possible role of H. pylori in the pathogenesis of bronchiectasis.

METHODS

Prospectively, bronchoalveolar lavage fluid (BALF) was obtained from patients with bronchiectasis (n=26) and control (n=20). BALF was subjected to polymerase chain reaction (PCR) to determine the presence of H. pylori and serum IgG against H. pylori was determined with micro-ELISA kit. In addition, PCR was performed to determine H. pylori in surgically removed lung tissues from patients with bronchiectasis (n=97).

RESULTS

H. pylori DNA was not detected in the BALF or in lung tissue samples. In addition, anti-H. pylori IgG level in patients with bronchiectasis did not show statistically significant difference from that of the control.

CONCLUSIONS

Our study provided evidence that there might be no direct association between H. pylori and bronchiectasis; however, the indirect role of soluble products of H. pylori could not be excluded.

Infection as a risk factor for stroke

Persisting disability requiring professional healthcare or help in daily life activities can be expected in a third to a half of all stroke survivors. It is mainly the elderly that are affected. For the increasingly aging population of Western societies, stroke represents an increasing social and economic burden. Besides the existing therapeutic options, additional treatment and prevention strategies are needed. Traditional risk factors do not explain all clinical and epidemiological features of stroke. Recently, the association between infectious and inflammatory processes and the occurrence of vascular disease has been established. This review summarizes the current evidence of infections as stroke risk factors and of potential anti-infective strategies as future methods of stroke prevention.

Virulent strains of Helicobacter pylori and vascular diseases: a meta-analysis

BACKGROUND

Cytotoxin-associated gene A (CagA)-positive strains of Helicobacter pylori are an etiological factor for peptic ulcer and gastric cancer. Studies on the role of these virulent strains in vascular diseases yield conflicting results.

METHODS

We searched the MEDLINE database for relevant studies. Meta-analysis was performed using the random effects method.

RESULTS

We found 10 retrospective case-control studies (with 1527 case patients and 1661 control subjects) and 3 prospective cohort studies (with 701 case patients and 1439 control subjects) on CagA status and ischemic heart disease and 4 retrospective case-control studies (with 513 case patients and 590 control subjects) on CagA status and cerebral ischemia. In the case-control studies, an association of ischemic heart disease with CagA-positive strains (OR 1.87, 95% CI 1.46-2.40) but no significant association with CagA-negative strains (OR 1.15, 95% CI 0.83-1.60) has been found; in the 3 prospective studies, association with ischemic heart disease was weaker but still significant (OR 1.26, 95% CI 1.05-1.51). In the 4 case-control studies, CagA-positive strains were significantly associated with cerebral ischemia (OR 2.43, 95% CI 1.89-3.13), again with no association for CagA-negative strains.

CONCLUSIONS

We found a small but significant association between vascular diseases and virulent CagA-positive strains of H. pylori. The lack of association with CagA-negative strains further supports the hypothesis of an independent relationship between virulent strains of H. pylori and vascular diseases. The magnitude of the association with cerebral ischemia needs to be confirmed by prospective studies.

Helicobacter pylori seroprevalence in patients with chronic obstructive pulmonary disease and its relation to pulmonary function tests

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a slowly progressive condition characterized by poorly reversible airflow limitation that is associated with an abnormal inflammatory response of the lung. It has been shown that there is a seroepidemiological association of Helicobacter pylori (Hp) infection with many inflammatory conditions.

OBJECTIVE

In this study, we aimed to investigate seroprevalence in Hp patients with COPD and to determine whether there is an association between Hp infection and COPD.

METHODS

Forty-nine voluntary patients with COPD and 50 healthy control subjects of similar age and sex were included in the study. Hp-specific IgG was measured with a commercially available kit from venous blood samples.

RESULTS

Serum levels of Hp-specific IgG and Hp IgG seropositivity were significantly higher in the patients with COPD than in the control subjects (p < 0.001 and p = 0.006, respectively). In addition, when the patients with COPD were grouped according to Hp IgG seropositivity, forced expiratory volume in 1 s (FEV(1)) values were lower in the seropositive patients compared to seronegative patients, and Hp serum IgG levels were correlated with FEV(1) values, which indicate the severity of COPD, in the COPD group (r = -0.306, p = 0.032).

CONCLUSION

The results suggest that there is an association between Hp infection and COPD, and Hp IgG levels are correlated with the severity of COPD.

Helicobacter pylori seroprevalence in patients with coronary artery disease

Recent studies have suggested that chronic infections such as Helicobacter pylori may be a risk factor for coronary artery disease (CAD). The aim of thIS study was to investigate the seroprevalence of H. pylori in patients with CAD. We enrolled 151 patients with CAD (93 men and 58 women, aged 48.1 +/- 17.3 years [mean +/- SD]) and 149 control subjects matched by age and sex (90 men and 59 women, aged 51.4 +/- 13.9 years). An enzyme-linked immunosorbent assay immunoglobulin (Ig) G test for H. pylori diagnosis was performed on all enrolled subjects (CAD patients and controls). Ninety-one of 151 patients with CAD (60.2%) and 86 of the 149 subjects in the control group (57.7%) were H. pylori positive (P > 0.05). H. pylori infection rates were similar in patients with CAD and control groups. The main conclusion of this study is that H. pylori infection is not a risk factor for developing CAD. Further studies should be undertaken to confirm our results.

A Systematic Comparison of the Quality and Volume of Published Data Available on Novel Risk Factors for Stroke versus Coronary Heart Disease

BACKGROUND

To identify new treatments to prevent stroke, it is important that we have reliable data on potential novel risk factors.

METHODS

We studied seven novel vascular risk factors [apo-lipoprotein (b), C-reactive protein, Chlamydia pneumoniae, fibrin-D dimer, fibrinogen, Helicobacter pylori and lipoprotein (a)] and compared the amount of published data on their relations with ischaemic stroke versus acute coronary events by systematic review of all studies published up to 2003.

RESULTS

From a total of 22,875 abstracts reviewed, 266 eligible studies were identified (167 case-control studies and 99 cohort studies). Two hundred and eleven (79%) studies included coronary events as an outcome for the purpose of a risk factor analysis. In 186 (70%) studies, coronary events were the only outcome that was analysed. Only 73 (27%) studies included stroke or TIA as an outcome event, and only 45 studies (17%) reported risk factor analyses for ischaemic stroke separately. These results were qualitatively consistent across the risk factors studied and the relative lack of data on risk factors for stroke was even greater in prospective cohort studies.

CONCLUSION

Data on novel risk factors for stroke are lacking compared with the equivalent data for acute coronary events, and there are very few data on specific subtypes of ischaemic stroke.

The association between Helicobacter pylori infection and adult height

OBJECTIVES

A cross-sectional survey was performed to evaluate the association between H. pylori and adult height.

METHODS

H. pylori infection was assessed using a 13C-urea breath test and height measured by a research nurse using a stadiometer in participants between the ages of 40-49 years.

RESULTS

Height was measured in 2932/3682 participants that attended and were evaluable. H. pylori infected women were 1.4 cm shorter than uninfected women (95% confidence interval, CI = 0.7-2.1 cm) and this statistically significant difference persisted after adjusting for age, ethnicity, childhood and present socio-economic status (H. pylori positives 0.79 cm shorter; 95%CI: 0.05-1.52 cm). H. pylori positive men were 0.7 cm shorter than uninfected men but this did not reach statistical significance (95% CI: -0.1-1.5 cm).

CONCLUSION

Although H. pylori infection is associated with reduced adult height in women, this maybe due to residual confounding.

Persistent infection and vascular disease: a systematic review

More than 150 epidemiological or clinical studies have reported on associations between vascular disease and the presence of certain persistent bacterial and viral agents, or of clinical conditions (e.g., periodontal disease) that are associated with persistent infection. This article provides a review of such studies, particularly in relation to Helicobacter pylori, Chlamydia pneumoniae, dental disease and cytomegalovirus (CMV), as well as references to possible mechanisms. The association between coronary heart disease and H. pylori or between heart disease and dental disease may be accounted for by residual confounding. Although markers of C. pneumoniae infection are around twenty times more common in atherosclerotic plaques than in disease-free blood vessels, the sequence of infection and disease is uncertain. For CMV, a limited number of patients with classic atherosclerotic coronary heart disease have been investigated in seroepidemiological studies. For all such agents, better and larger seroepidemiological and pathology-based studies are needed to resolve these uncertainties, as well as - at some stage - large-scale, randomised intervention studies.