Helicobacter pylori infection and mortality from ischaemic heart disease: negative result from a large, prospective study

Effect of Helicobacter Pylori Infection on Glucose Metabolism, Lipid Metabolism and Inflammatory Cytokines in Nonalcoholic Fatty Liver Disease Patients

Objective

To probe into the influence of Helicobacter pylori (Hp) infection on glucose metabolism, lipid metabolism, and inflammatory cytokines in patients with nonalcoholic fatty liver disease (MASLD).

Methods

A total of 140 MASLD patients admitted to our Hospital between June 2020 and May 2021 were selected as the research objects. Based on the presence or absence of Hp infection, they were divided into the study group (73 cases with infection) and control group (67 cases without infection). Glucose metabolism indicators [fasting blood glucose (FBG), 2-hour postprandial glucose (2hPG), fasting insulin (FINS), glycated hemoglobin (HbAlc)], lipid metabolism indicators [total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)], and inflammatory indicators [interleukin-37 (IL-37), interleukin-18 (IL-18)] were measured and compared between the two groups.

Results

In terms of glucose metabolism indicators, the study group exhibited higher levels of FBG (5.84±0.49 vs 5.40±0.51, t=2.535, P=0.012), 2hPG (7.26±1.30 vs 6.50±1.53, t=3.321, P<0.001), and FINS (11.13±4.13 vs 9.12±3.72, t=3.224, P<0.001), and Insulin resistance index (HOMA-IR) (2.97±0.35 VS 2.13±0.54, t=3.761, P<0.001) and a lower level of HbAlc (5.25±0.56 vs 6.12±0.57, t=5.473, P<0.001) compared to the control group. Regarding lipid metabolism indicators, the study group exhibited higher levels of TC (5.64±1.49 vs 5.01±1.32, t=3.332, P<0.001), TG (1.89±0.34 vs 1.32±0.43, t=3.411, P<0.001), and LDL-C (3.31±0.43 vs 2.12±0.29, t=4.142, P<0.001), and a lower level of HDL-C (1.45±0.21 vs 1.78±0.42, t=4.347, P<0.001) compared to the control group. As for the inflammatory indicators, the study group exhibited higher levels of IL-37 (45.56±6.02 vs 34.02±3.28, t=9.332, P<0.001) and IL-18 (73.57±5.82 vs 60.34±4.84, t=10.141, P<0.001) compared to the control group.

Conclusion

It is crucial to place appropriate emphasis on the impact of Hp infection on the glucose metabolism, lipid metabolism, and inflammatory response in MASLD patients, warranting careful consideration during the treatment of these patients.

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.

Association of Helicobacter pylori infection with coronary artery disease: is it an independent risk factor?

BACKGROUND

Coronary artery disease (CAD) is a dilemma and a serious cause of morbidity and mortality worldwide. Since CAD has been seen in people without the conventional risk factors like smoking, diabetes, and hypertension, the infectious theory being a risk factor has arisen.

MAIN BODY

Helicobacter pylori (HP) infection is the most common infection affecting the vast majority of the population worldwide. HP grows in the gastrointestinal tract (GIT) and responsible for chronic gastritis, peptic ulcer, gastric adenocarcinoma, and gastric lymphoma. A review of medical literature mainly PubMed has revealed several studies reporting that HP pathogenesis extends beyond the GIT to be a predisposing factor for atherosclerosis, dyslipidemia, thrombosis, and CAD. However, it remains a controversial issue that warrants extensive research.

CONCLUSION

This article gives insight into the diversity of opinions, evidence, and theories regarding the association between HP infection and CAD. The idea that CAD may be managed with antibiotics in certain patients seems to be creative and inspiring. More research is mandatory to either verify or reject this proposed correlation with strong scientific evidence and also to demonstrate the implications of the results on CAD management and outcome.

Gut Microbiota: The Missing Link Between Helicobacter pylori Infection and Metabolic Disorders?

Helicobacter pylori (H. pylori) is a gram-negative bacterium that infects approximately 4.4 billion individuals worldwide. Although the majority of infected individuals remain asymptomatic, this bacterium colonizes the gastric mucosa causing the development of various clinical conditions as peptic ulcers, chronic gastritis and gastric adenocarcinomas and mucosa-associated lymphoid tissue lymphomas, but complications are not limited to gastric ones. Extradigestive pathologies, including metabolic disturbances such as diabetes, obesity and nonalcoholic fatty liver disease, have also been associated with H. pylori infection. However, the underlying mechanisms connecting H. pylori with extragastric metabolic diseases needs to be clarified. Notably, the latest studies on the topic have confirmed that H. pylori infection modulates gut microbiota in humans. Damage in the gut bacterial community (dysbiosis) has been widely related to metabolic dysregulation by affecting adiposity, host energy balance, carbohydrate metabolism, and hormonal modulation, among others. Taking into account that Type 2 diabetic patients are more prone to be H. pylori positive, gut microbiota emerges as putative key factor responsible for this interaction. In this regard, the therapy of choice for H. pylori eradication, based on proton pump inhibitor combined with two or more antibiotics, also alters gut microbiota composition, but consequences on metabolic health of the patients has been scarcely explored. Recent studies from our group showed that, despite decreasing gut bacterial diversity, conventional H. pylori eradication therapy is related to positive changes in glucose and lipid profiles. The mechanistic insights explaining these effects should also be addressed in future research. This review will deal with the role of gut microbiota as the linking factor between H. pylori infection and metabolic diseases, and discussed the impact that gut bacterial modulation by H. pylori eradication treatment can also have in host's metabolism. For this purpose, new evidence from the latest human studies published in more recent years will be analyzed.

A meta-analysis of the association between Helicobacter pylori infection and risk of atherosclerotic cardiovascular disease

BACKGROUND

Helicobacter pylori (H pylori) infection may be a risk factor for cardiovascular disease (CVD), but the reported researches have given conflicting results.

AIMS

To investigate the association between H pylori infection and risk of atherosclerotic CVD.

MATERIALS AND METHODS

The studies were retrieved in Embase, PubMed, Web of Science (published from Jan 1, 1990, to Jan 31, 2020, language restrictions: English). All studies included used data from case-control studies and cohort studies of cardiovascular adverse events. Random effect models were used to measure pooled estimates. All data were analyzed with Stata 11.2 SE (StataCorp, College Station, TX).

RESULTS

Helicobacter pylori infection increased the risk of adverse cardiovascular events by 51% (40 studies, n = 19 691, odd ratio [OR] = 1.51, 95% confidence interval [CI]: 1.34-1.70). The effect was greater for studies that the type of CVDs was myocardial infarction (MI) and cerebrovascular disease (MI OR = 1.80, 95% CI: 1.42-2.26, cerebrovascular disease OR = 1.54, 95% CI: 1.27-1.89). Meanwhile, CagA seropositive H pylori strains were associated with a significantly increased risk of cardiovascular adverse events based on published research data (OR = 1.73, 95% CI: 1.40-2.14).

CONCLUSION

In conclusion, H pylori infection enhanced the risk of atherosclerotic cardiovascular adverse events, especially in some patients with MI and cerebrovascular disease. This study will provide guidance for the targeted prevention and treatment of CVDs. But this association need to be confirmed by more prospective studies.

Positive Association Between Helicobacter pylori Infection and Metabolic Syndrome in a Korean Population: A Multicenter Nationwide Study

BACKGROUND AND AIM

Helicobacter pylori (H. pylori) infection causes extra-gastrointestinal as well as gastric diseases. This analytical cross-sectional study was performed to investigate the association between H. pylori infection and metabolic syndrome in a Korean population.

METHODS

Anthropometric and metabolic data, as well as anti-H. pylori IgG antibodies, were measured in 21,106 subjects who participated in a health checkup between January 2016 and June 2017. The classification of metabolic syndrome followed the revised National Cholesterol Education Program criteria.

RESULTS

After excluding subjects with a history of H. pylori eradication therapy, or gastric symptoms, the seropositivity of H. pylori was 43.2% in 15,195 subjects. H. pylori-positive participants had significantly higher body mass index (BMI), waist circumference, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and lower high-density lipoprotein (HDL-C) than did seronegative participants (P < 0.05). After adjusting for confounders, high TC, low HDL-C, and high LDL-C were associated with H. pylori seropositivity. Finally, the prevalence of metabolic syndrome was higher in H. pylori-seropositive subjects than in negative ones (27.2% vs. 21.0%, P < 0.05), and H. pylori seropositivity increased the likelihood of metabolic syndrome (OR 1.19, 95% CI 1.09-1.31, P < 0.001) after adjusting for sex, age, BMI, smoking, residence, household income, and education level. However, the association between H. pylori seropositivity and metabolic syndrome disappeared in those ≥ 65 years old.

CONCLUSIONS

H. pylori infection plays an independent role in the pathogenesis of metabolic syndrome in Koreans under 65 years old.

Helicobacter pylori infection is not related to increased carotid intima-media thickness in general population

The aim is to determine whether there is an independent association between Hp infection and carotid intima-media thickness (CIMT) in a cross-section observational study. Among of 14588 routine health check-up participants, 13770 subjects underwent the ¹³C-urea breath test (¹³C-UBT) and ultrasound measurement of CIMT. Traditional atherosclerotic risk factors were also recorded. The ratio of increased CIMT in Hp positive group (28.6%) was not significant difference compared with Hp negative group (29.7%) (p = 0.164). The HP infection rates was no significant difference between increased CIMT (38.4%) and non- increased CIMT (39.7%) patients. However, all the traditional atherosclerotic risk factors including age, gender, BMI, waistline, total cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides, free fatty acid, homocysteine, systolic and diastolic blood pressure, fasting plasma glucose and C reactive protein were different between increased CIMT and non- increased CIMT participants. The odds of Hp infection for CIMT risk (OR 0.948; 95% CI 0.879-1.022; P = 0.164) was not higher in binary logistic regression analysis even after adjustment for traditional risk factors (OR 1.118; 95% CI 0.958-1.306; P = 0.157). Our study found no evidence of association between CIMT and HP infection.

A Meta-Analysis of the Association between Helicobacter pylori Infection and Risk of Coronary Heart Disease from Published Prospective Studies

BACKGROUND

The association between helicobacter pylori (Hp) infection and coronary heart disease (CHD) has long been debated, and the results from previous meta-analysis are varied.

AIMS

The aim for this study was to identify the association between Hp and CHD using published perspective cohort studies.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed on studies published from January, 1992 to April, 2014. All studies included used data from prospective cohort studies of CHD events or CHD deaths. Random effect models were applied in all estimations.

RESULTS

H. pylori infection increased the risk of CHD events by 11% (19 studies, n = 22,207, risk ratio (RR) = 1.11, 95% confidence interval (CI): 1.01-1.22). This effect was greater for studies that had less than 5 years' follow-up time (RR = 1.15, 95% CI: 1.00-1.32). However, this effect was not significant for studies that had follow-up times ≥10 years (n = 5100, RR = 1.04, 95% CI: 0.87-1.24). Neither Cag-A seropositive nor Cag-A seronegative strains of H. pylori were associated with a significantly increased risk of CHD events or deaths based on the current published data.

CONCLUSION

In conclusion, H. pylori infection increased the risk of CHD events, especially in a patient's early life, but this association was weaker or might be masked by other CHD risk factors in long-term observations.

Helicobacter Pylori Infection and Risk of Death From Cardiovascular Disease Among the Japanese Population: a Nested Case-Control Study within the JACC Study

AIM

An increasing number of studies have linked Helicobacter pylori (H. pylori) infection to extragastric diseases; however, the role of H. pylori in the pathogenesis of cardiovascular disease (CVD) remains controversial. We examined the association between H. pylori infection and risk of death from coronary heart disease (CHD) and stroke in a nested case-control study within a large prospective cohort study of Japanese subjects.

METHODS

The cases were 627 subjects who died from CHD and stroke during the follow-up period until December 31, 2003, and 627 control subjects were selected and matched to cases on sex, age, and area. Commercial immunoassay IgG enzyme-linked immunosorbent assay kits were used for the determination of the seropositivity for H. pylori. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using a conditional logistic regression model.

RESULTS

Overall, H. pylori infection was not associated with CVD (CHD and stroke) mortality risk. The multivariable OR was 0.96 (0.76-1.21) for the H. pylori positive subjects in comparison with H. pylori negative subjects. As for the subtype of CVD, H. pylori appears to be inversely associated with the risk of death from CHD, with an OR of 0.79 (0.50-1.25), but this was not statistically significant. No significant association was observed between H. pylori infection and stroke, with an OR of 1.02 (0.78-1.33).

CONCLUSION

The results of this nested case-control study suggest that there is no association between H. pylori infection and CHD and stroke mortality risk in otherwise healthy, elderly Japanese individuals.

Effects of Helicobacter pylori infection and its eradication on lipid profiles and cardiovascular diseases

BACKGROUND

We aimed to examine the relationship of current Helicobacter pylori infection with lipid profile and cardiovascular disease and its eradication effect.

METHODS

Healthy subjects, who underwent routine checkup between October 2003 and December 2007, were followed up until June 2009. Helicobacter pylori and lipid profiles were measured both baseline and follow-up. Multiple logistic regression models for odds ratios (ORs) and 95% confidence intervals (CIs) were used to estimate the effects of H. pylori infection and its eradication, on lipids and cardiovascular disease.

RESULTS

Current infection with H. pylori with 50.5% (6759/13383) at baseline increased low-density lipoprotein (LDL) and decreased high-density lipoprotein (HDL) than H. pylori-negative group. Successful eradication of H. pylori decreased the risk of high LDL compared with the persistent infection (OR 0.76, 95% CI 0.59-96), which was comparable to that of the persistent negative group (OR 0.82, 95% CI 0.70-0.97), and decreased the risk of low HDL (OR 0.68, 95% CI 0.49-0.96). Current infection of H. pylori increased the risk of cardiovascular disease (OR 3.27, 95% CI 1.31-8.14) at baseline, but its eradication failed to decrease the risk at a 2-year follow-up. However, persistent negative infection decreased the risk (OR 0.57, 95% CI 0.35-0.94) comparing to persistent positive infection at follow-up.

CONCLUSIONS

Current infection with H. pylori had a positive association with high LDL, low HDL, and cardiovascular disease. Successful H. pylori eradication decreased the risk of high LDL and low HDL, but did not reduce the risk of cardiovascular disease.

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 of Helicobacter pylori infection with coronary artery disease: is Helicobacter pylori a risk factor?

BACKGROUND

Helicobacter pylori (HP) infection is the most common infection in the world and coronary artery disease (CAD) is probably associated with it. The aim of this prospective study was to evaluate the association between HP infection and CAD in suspected patients referred for coronary angiography. The coronary angiography was performed using Judkins method and patients were assigned to participate in CAD positive (>50% luminal diameter stenosis) and negative groups. The serum HP IgG antibody was checked.

RESULTS

Positive and negative CAD groups consisted of 62 and 58 patients, respectively. HP was more prevalent among CAD+ patients, and with increasing the number of coronary arteries with stenosis, the HP seropositivity increased so that 76.3% of patients with multiple vessel diseases (MVD) and 70% of patients with single vessel diseases (SVD) were HP seropositive versus 50% in control group (P = 0.006). Positive CAD was significantly associated with HDL level (P = 0.01) and ESR level (P = 0.006). Also, CAD+ patients had higher CRP levels than controls and it was statistically different between SVD group and controls (P < 0.05).

CONCLUSION

HP infection is more prevalent in CAD positive patients and, in case of proving causal relationship, it can be considered as a reversible risk factor for CAD.

The combination of Helicobacter pylori- and cytotoxin-associated gene-A seropositivity in relation to the risk of myocardial infarction in middle-aged Japanese: The Japan Public Health Center-based study

BACKGROUND

Limited evidence is available concerning the impact of the combination of Helicobacter pylori- (H. pylori) and cytotoxin-associated gene-A (CagA)-positivity on the risk of myocardial infarction (MI) and stroke, particularly in Asian populations, in which the prevalence of H. pylori infection is high.

METHODS

A prospective, nested case-control study was conducted to examine the association between H. pylori and CagA and risk of MI and stroke within a cohort of 29,876 men and women aged 40-69 years with no history of heart disease, stroke or cancer. Participants completed a risk factor survey and donated blood samples between 1990 and 1994. Systematic cardiovascular surveillance was performed through 2002. One control for each stroke case and two controls for each MI case were matched by sex, age, date of blood sampling, time since last meal and study location.

RESULTS

During the follow-up period, there were 600 strokes and 106 MIs. H. pylori-IgG positivity was not associated with the risk of MI, while CagA positivity tended to be associated with it (OR = 1.72, 95%CI: 0.91-3.26, p = 0.10). We found no association between H. pylori or CagA and risk of stroke.

CONCLUSIONS

H. pylori infection was not significantly associated with risk of MI and stroke among middle-aged Japanese. However, CagA positivity tended to be associated with MI.

Comorbidities affect risk of nonvariceal upper gastrointestinal bleeding

BACKGROUND & AIMS

The incidence of upper gastrointestinal bleeding (GIB) has not been reduced despite the decreasing incidence of peptic ulcers, strategies to eradicate Helicobacter pylori infection, and prophylaxis against ulceration from nonsteroidal anti-inflammatory drugs. Other factors might therefore be involved in the pathogenesis of GIB. Patients with GIB have increasing nongastrointestinal comorbidity, so we investigated whether comorbidity itself increased the risk of GIB.

METHODS

We conducted a matched case-control study using linked primary and secondary care data collected in England from April 1, 1997 through August 31, 2010. Patients older than 15 years with nonvariceal GIB (n = 16,355) were matched to 5 controls by age, sex, year, and practice (n = 81,636). All available risk factors for GIB were extracted and modeled using conditional logistic regression. Adjusted associations with nongastrointestinal comorbidity, defined using the Charlson Index, were then tested and sequential population attributable fractions calculated.

RESULTS

Comorbidity had a strong graded association with GIB; the adjusted odds ratio for a single comorbidity was 1.43 (95% confidence interval [CI]: 1.35-1.52) and for multiple or severe comorbidity was 2.26 (95% CI: 2.14%-2.38%). The additional population attributable fraction for comorbidity (19.8%; 95% CI: 18.4%-21.2%) was considerably larger than that for any other measured risk factor, including aspirin or nonsteroidal anti-inflammatory drug use (3.0% and 3.1%, respectively).

CONCLUSIONS

Nongastrointestinal comorbidity is an independent risk factor for GIB, and contributes to a greater proportion of patients with bleeding in the population than other recognized risk factors. These findings could help in the assessment of potential causes of GIB, and also explain why the incidence of GIB remains high in an aging population.

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.

H. pylori-Induced Higher C-Reactive Protein in Obese African Americans

African Americans are more susceptible to develop insulin resistance, obesity, Type 2 Diabetes, and coronary heart disease (CHD), and systemic inflammation is central to the pathophysiology of these chronic diseases. African Americans are also more likely to contract H. pylori (cagA) infections during their childhood. However, the contribution of H. pylori infection to the degree of overall systemic inflammation in these chronic diseases is not known. Therefore, we studied 46 apparently healthy African Americans, over 40 years of age who were, infected with H. pylori (cagA). These volunteers were assessed at baseline and after treatment with triple regimen drug therapy to eradicate H. pylori. All but 3 subjects were found to be free of this infection by urea breath test (UBT) after the treatment period. No hyperhomocysteinemia was found in these subjects and there were no significant changes in the level of homocysteine (tHcy), folate and B(12); however, CRP levels measured by high sensitivity assay showed a significant (p=0.02) decrease 2 months after the eradication. We further stratified CRP values according to the BMI < 27 and > 27. There was more profound reduction in CRP in the more obese group (i.e., BMI>27) from 54.26 ± 23.67 to 18.73 ± 17.39 mg/l (p=0.01), compared with the leaner subjects in whom CRP decreases from 8.88 ± 6.23 to 4.94 ± 6.21 mg/L (p=0.04), after eradication of the H. pylori (cagA) infection. The level of CRP, however, remained significantly higher in the obese subjects even after the eradication of this infection, indicative of a smaller residual influence of adiposity on CRP. Thus, a major component of systemic inflammation in African Americans may be attributable to chronic H. pylori infection.

Helicobacter pylori infection and arterial stiffness in patients with type 2 diabetes mellitus

Epidemiologic studies have suggested possible atherogenic roles for such pathogens as Chlamydia pneumoniae, Helicobacter pylori (Hp), cytomegalovirus, and herpes simplex virus. The aim of the present study was to examine the relationship between seropositivity of antibodies to Hp (Hp infection) and arterial stiffness determined by pulse wave velocity (PWV) in 130 patients (73 men and 57 women) with type 2 diabetes mellitus without a history of cardiovascular disease. The prevalence of Hp infection in patients with type 2 diabetes mellitus was 53.8%. Age (66.7 +/- 11.3 vs 60.0 +/- 12.2 years, P = .0014) and systolic blood pressure (138 +/- 19 vs 131 +/- 22 mm Hg, P = .0420) were significantly higher in patients with Hp infection than in those without. Serum C-reactive protein was higher in patients with Hp infection than in those without, although it did not reach statistical significance (0.23 +/- 0.27 vs 0.18 +/- 0.20 mg/dL, P = .2205). Pulse wave velocity was significantly higher in patients with Hp infection than in those without (1877 +/- 550 vs 1585 +/- 331 cm/s, P = .0005). Multiple regression analysis demonstrated that age (beta = .388, P < .0001), mean arterial pressure (beta = .289, P = .0006), hypertensive treatment (beta = .185, P = .0282), and presence of Hp infection (beta = .169, P = .0220) were independent determinants of PWV. In conclusion, Hp infection is associated with arterial stiffness determined by PWV in patients with type 2 diabetes mellitus.

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.

Asia-Pacific consensus guidelines on gastric cancer prevention

BACKGROUND AND AIM

Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

METHODS

A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded.

RESULTS

Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. First-line treatment of H. pylori infection should be in accordance with national treatment guidelines.

CONCLUSION

A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

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.

A review of the postulated mechanisms concerning the association of Helicobacter pylori with ischemic heart disease

Since its discovery, Helicobacter pylori has been implicated in the pathogenesis of several diseases, both digestive and extradigestive. Interestingly, the majority of the extradigestive-related literature is focused on two vascular manifestations: stroke and ischemic heart disease. Potential mechanisms for the establishment of a H. pylori-induced ischemic heart disease have been proposed with regard to chronic inflammation, molecular mimicry, oxidative modifications, endothelial dysfunction, direct effect of the microorganism on atherosclerotic plaques as well as changes regarding traditional or novel risk factors for ischemic heart disease or even platelet-H. pylori interactions. A positive link between H. pylori infection and ischemic heart disease has been suggested by a series of studies focusing on epidemiologic evidence, dyslipidemic alterations, upregulation of inflammatory markers or homocysteine levels, induction of hypercoagulability, oxidation of low-density lipoprotein, causation of impaired endothelial function, detection of H. pylori DNA in atherosclerotic plaques, and participation of certain antigens and antibodies in a cross-reactivity model. There are studies, however, which investigated the relationship between H. pylori and ischemic heart disease with regard to the same parameters and failed to confirm the suggested positive association. Further studies in the direction of interaction between H. pylori and the host's genotype as well as a quest for evidence towards novel risk factors for ischemic heart disease such as oxidative stress, vascular remodeling, vascular calcification, or vasomotor activity, may reveal a field of great interest, thus contributing to the determination of new potential mechanisms.

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.

Gastric helicobacter infection induces a Th2 phenotype but does not elevate serum cholesterol in mice lacking inducible nitric oxide synthase

Persistent Helicobacter felis infection in (C57BL/6 x 129SvEv)F1 mice induces chronic gastritis. Expression of inducible nitric oxide synthase (iNOS) is upregulated in response to Helicobacter infection. In this study, 20 10-week-old iNOS-/- mice and 20 wild-type [(C57BL/6 x 129SvEv)F1] mice were infected with H. felis by oral gavage and were assessed histologically and serologically at 32 weeks postinfection. Equal numbers of uninfected controls were sham inoculated. The mice were scored for severity of gastric inflammation, hyperplasia, glandular atrophy, and mucous metaplasia in the corpus and for the level of helicobacter colonization. The immunoglobulin G1 (IgG1), IgG2a, and IgG2c antibody responses to H. felis were determined. As a secondary measure, serum cholesterol levels were assessed. iNOS-/- mice have a propensity for increased serum cholesterol, and although controversial, several human epidemiologic studies have demonstrated an association between Helicobacter infection and several risk factors for cardiovascular disease, including elevated serum cholesterol. Nevertheless, no differences in serum cholesterol levels were observed between the H. felis-infected and -uninfected iNOS-/- mice in this study. The uninfected animals had minimal to no gastric pathology. The gastric pathology scores for the infected animals were reduced significantly in the iNOS-deficient mice relative to those for the wild-type mice (all P <0.01). Helicobacter-infected iNOS-/- mice had chronic lymphoid infiltration and negligible to mild glandular atrophy and mucous metaplasia in the fundic mucosa, while H. felis-infected wild-type mice had severe atrophic and metaplastic mucosal changes. The atrophic gastritis in the infected wild-type mice, particularly the female mice, was also accompanied by greater granulocytic infiltration, antral hyperplasia, and diminished antral colonization, unlike that in the infected iNOS-/- mice. iNOS-/- mice developed significantly lower Th1-associated IgG2c antibody responses to H. felis (P <0.0003); the Th2-associated IgG1 responses were similar (P=0.09), suggesting a greater effect of the iNOS defect on Th1 responses. H. felis colonization was significantly greater in the iNOS-deficient mice. These findings are indicative of an impaired Th1 component of the H. felis-induced inflammatory response when the influence of iNOS is removed.

Hepatitis B virus infection and coronary atherosclerosis: Results from a population with relatively high prevalence of hepatitis B virus

AIM: To investigate the possible association between hepatitis B virus (HBV) infection and angiographically proven coronary artery disease (CAD) in a population with relatively high prevalence of HBV.

METHODS: Sera from 434 patients who underwent coronary angiography were tested for HBV antigens (HBsAg, HBeAg) and antibodies (Anti-HBs, Anti-HBc and Anti-HBe) by ELISA.

RESULTS: Seventy-seven percent (224/291) of the patients with CAD and 73.4% (105/143) of the patients without angiographic evidence of atherosclerosis were seropositive for HBV (P>0.05). However, C-reactive protein (CRP) levels were significantly higher in patients with CAD (P = 0.008), while lower in HBV seropositive population (P = 0.043 and P = 0.021 after adjustment for conventional risk factors).

CONCLUSION: Our results suggested HBV infection negatively correlates with CRP levels, but seems not to be associated with coronary atherosclerosis.

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.

Biological foundation for periodontitis as a potential risk factor for atherosclerosis

OBJECTIVES

Links between periodontal diseases and systemic diseases have been well documented by epidemiological studies. Recently, research has shifted to elucidating the biologic mechanism for a causal relationship. One focus of interest is atherosclerosis, the underlying event of cardiovascular diseases due to its serious health impact. However, it is still not clear whether periodontopathic pathogens are truly etiologic agents or ubiquitous bystanders. This article reviews the current understanding about the molecular biological interactions between periodontal disease and atherosclerosis and the biological plausibility of periodontitis as a potential risk factor for cardiovascular disease.

MATERIALS AND METHODS

The current literature regarding periodontal diseases and atherosclerosis and coronary vascular disease was searched using the Medline and PubMed databases.

RESULTS

In vitro experiments and animal models are appropriate tools to investigate the biological interactions between periodontal disease and atherosclerosis at the cell molecular level. The concepts linking both pathologies refer to inflammatory response, immune responses, and hemostasis. In particular, Porphyromonas gingivalis appears to have unique, versatile pathogenic properties. Whether or not these findings from isolated cells or animal models are applicable in humans with genetic and environmental variations is yet to be determined. Likewise, the benefit from periodontal therapy on the development of atherosclerosis is unclear. Approaches targeting inflammatory and immune responses of periodontitis and atherosclerosis simultaneously are very intriguing.

CONCLUSION

An emerging concept suggests that a pathogenic burden from different sources might overcome an individual threshold culminating in clinical sequela. P. gingivalis contributes directly and indirectly to atherosclerosis.

Oxidized low-density lipoprotein levels circulating in plasma and deposited in the tissues: comparison between Helicobacter pylori-associated gastritis and acute myocardial infarction

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL) is a key factor in the progression of atherosclerosis. We developed a sensitive method for measuring plasma ox-LDL levels using a novel anti-ox-LDL antibody. Recently, several studies have shown positive associations between Helicobacter pylori (H pylori) infection and coronary heart disease. Thus the question arises whether an increase in the plasma levels of ox-LDL occurs in patients with H pylori gastritis.

METHODS

We measured plasma ox-LDL levels in patients with H pylori gastritis (n = 27) and compared them with those in patients with acute myocardial infarction (AMI) (n = 62) and stable angina pectoris (SAP; n = 63) and those in control subjects (n = 64). In addition, ox-LDL localization and the presence of macrophages and neutrophils were studied immunohistochemically in gastritis specimens and in coronary culprit lesions obtained from patients with AMI.

RESULTS

Plasma ox-LDL levels in patients with AMI were significantly higher than those in patients with SAP (P <.0001), patients with H pylori gastritis (P <.0001), or in control subjects (P <.0001; AMI, 1.34 +/- 0.95; SAP, 0.61 +/- 0.29; Gastritis, 0.53 +/- 0.17; control, 0.57 +/- 0.23 ng/5 microg LDL protein). Immunohistochemically, H pylori gastritis specimens showed distinct infiltration of macrophages and myeloperoxidase-positive neutrophils; however, ox-LDL localization was not detected. In contrast, coronary culprit plaques revealed strong positivity for ox-LDL in ruptured lipid cores with abundant macrophage-derived foam cells, and these plaques also contained myeloperoxidase-positive neutrophils.

CONCLUSION

Our results suggest that plasma ox-LDL levels do not seem to be associated with H pylori infection, but do relate to coronary plaque instability in AMI.

Helicobacter pylori and Alzheimer's disease: a possible link

BACKGROUND: Although serological findings indicate the presence of a relationship between Helicobacter pylori (HP) and vascular disease, no data have been reported about a possible association of HP with dementia. The aim of the present study was to determine whether chronic HP infection might play a role in Alzheimer's disease (AD). METHODS: Plasma homocysteine level, serum folate and vitamin B(12) concentrations, plasma pyridoxal phosphate level, IgG and IgA antibodies to HP, and C-reactive protein (CRP) were determined in 30 AD patients, 30 patients affected by vascular dementia (VaD), and 30 control subjects. All patients and control subjects were matched for age, educational level, and nutritional and socioeconomic status. None of the subjects had a history of chronic gastritis, peptic ulcer, gastric cancer, or major abdominal surgery. RESULTS: HP-IgG level was significantly increased in VaD patients as compared to controls and AD patients, while AD patients had HP-IgG levels higher than those of normal controls. HP-IgA levels were equally increased in both VaD and AD patients. CRP was higher in AD patients than in VaD patients and controls, although CRP levels in VaD patients were also significantly increased. CONCLUSIONS: The present study found an association between HP infection and AD. The question remains as to whether this association is due to the ubiquity of HP, or whether it contributes to the neuroinflammatory process in AD. The relationship between HP and AD, if confirmed by additional studies with a greater number of patients, may have important clinical and therapeutic implications.

Helicobacter pylori eradication decreases blood neutrophil and monocyte counts

BACKGROUND

The effect of Helicobacter pylori infection on systemic disorders is not well understood.

AIM

The purpose of this study was to elucidate the systemic effects of H. pylori infection by comparing differential counts of leukocytes and platelets in peripheral blood before and after eradication of H. pylori.

METHODS

A total of 164 H. pylori-positive patients underwent eradication therapy, and populations of peripheral blood leukocytes and platelets before and 0 (just after therapy), 1, 3 and 12 months after eradication were retrospectively analysed.

RESULTS

In the eradicated group (n = 138), blood leukocytes, neutrophils and monocytes decreased significantly after eradication, but there was no significant change in eosinophils, basophils, lymphocytes or platelets. In the non-eradicated group (n = 26), there was no significant change in any studied parameter. With regard to smoking status, although leukocytes and neutrophils did not decrease after eradication in the smoking group, they significantly decreased after eradication in the nonsmoking group.

CONCLUSIONS

These findings suggest that: (1) H. pylori infection increases neutrophil and monocyte counts in the peripheral blood, which indicates a significant role of H. pylori infection in systemic disorders; and (2) Smoking may mask the effect of H. pylori eradication on peripheral leukocytes, which would explain the controversy in previous reports concerning H. pylori infection and peripheral leukocytes.

Cardiac heart disease in the era of sucrose polyester, Helicobacter pylori and Chlamydia pneumoniae

Recent evidence associates inflammatory mediators with coronary heart disease. Elevation of acute-phase reaction (APR) proteins such as serum amyloid A, fibrinogen, CRP and haptoglobin in response to Helicobacter pylori (H. pylori) infection was shown to initiate gastritis and ischemic heart disease. Positive Chlamydia pneumoniae (C. pneumoniae) serology is associated with increased levels of inflammatory cytokines and tumor necrosis factor-alpha (TNF-alpha), which stimulates endothelial cell activation, procoagulant activity and angiogenesis in patients with coronary heart disease. As a final example, interleukin-6 (IL-6) has been proposed to mediate cardiovascular disorders. Public awareness of risks of excessive body weight and high levels of serum cholesterol propelled the development of synthetic dietary components such as sucrose polyester (SPE) to substitute for natural lipids. SPE is a synthetic lipid whose physical properties are similar to a natural triacylglycerol with a similar assortment of fatty acids and is resistant to lipolysis by gastric and pancreatic enzymes. Intake of SPE in lieu of natural lipids is expected to decrease absorption of essential fatty acids (EFA) and fat-soluble vitamins among other essentials. Deficiency of EFA leads to the formation of faulty cellular membranes, which is manifested as skin lesions, growth failure, erythrocyte fragility, impairment of fertility and uncoupling of oxidation and phosphorylation. Possibilities of absorption of these synthetic lipids into the circulation may represent an unexpected health hazard. We have shown that subcutaneous (sc) administration to rabbits of a range of lipolysis-resistant lipid-like sorbitol, mannitol and arabitol esters of palmitic (P) and lauric (L) acids was found to evoke a mild APR, which in humans could contribute to CHD incidence. We suggest a reversal in the commonly accepted role of SPE as a sequestor of dietary lipid: SPE may be the lipophilic solute contained within the dietary lipid solvent micelle. An alternative conclusion regarding the biological effects of excessive dose of SPE in human and pig for a short time span should be considered.

Serological evidence of Helicobacter pylori infection in UK South Asian and European populations: implications for gastric cancer and coronary heart disease

OBJECTIVES

To describe the prevalence of serological evidence of infection with Helicobacter pylori among people of South Asian and European ethnic origins and to assess its association with prevalent coronary heart disease (CHD).

METHODS

We used a quantitative method to compare IgG antibodies to H. pylori in a population sample of 300 South Asians and 302 Europeans in Newcastle upon Tyne, UK.

RESULTS

For men and women, respectively, H. pylori IgG (95% confidence interval) was 16.7 microg/ml (13.9, 20.2) and 11.3 (9.4, 13.5) among Europeans and 11.6 (9.8, 13.7) and 14.3 (12.1, 16.9) among South Asians. Levels were higher in older participants and in those of lower socioeconomic status. The ratio of geometric mean IgG, (95% confidence interval) adjusted for age, sex and socioeconomic status, in those with and without CHD was 1.02 (0.49, 2.11) among Europeans and 1.79 (1.01, 3.17) among South Asians. Antibodies against staphylococcal enterotoxins A and B were higher among South Asians than Europeans.

CONCLUSIONS

The prevalence of H. pylori infection among UK South Asians does not reflect that of their countries of origin, nor their lower prevalence of gastric cancer. The association with CHD in South Asians requires corroboration in other studies.

Immunohistochemical testing for Helicobacter pylori infection in ascending aortic aneurysms and penetrating aortic ulcers

Evidence implicating Helicobacter pylori (H. pylori) in coronary artery disease and aneurysmal lesions is controversial. No published data have related H. pylori infection to ascending aortic aneurysms and penetrating ulcers, although both of these lesions may have an infectious components in their initiating process. We sought to investigate possible H. pylori infection in 54 human specimens of 42 aortic aneurysms and 12 penetrating ulcers. No evidence of H. pylori was found in these specimens.

Relationship between infectious burden, systemic inflammatory response, and risk of stable coronary artery disease: role of confounding and reference group

AIM

The purpose of the study was to assess the association between seropositivity to various infectious agents and stable coronary artery disease (CAD), controlling simultaneously for a variety of potential confounders. We also investigated whether the choice of a larger reference group might affect the results, and whether or not seropositivity to multiple agents was associated with a systemic inflammatory response.

METHODS

We assessed the simultaneous prevalence of antibodies against Helicobacter pylori, Chlamydia, cytomegalovirus, and herpes simplex virus in 312 patients with angiographically proven coronary artery disease (CAD) and in 479 age and sex matched controls. C-reactive protein, interleukin-6, fibrinogen, PAI-1-activity, D-dimer, von Willebrand Factor, plasma viscosity, and a complete blood cell count were determined in all subjects.

RESULTS

Seropositivity to all of the four agents was 21.8% in cases and 13.6% in controls (P=0.0003). We found a dose-response relationship between combined IgG-seropositivity to H. pylori, Chlamydia, cytomegalovirus, and herpes simplex virus and odds for the presence of angiographically confirmed stable CAD which, however, was strongly reduced after controlling for a variety of potential confounders. The dose-response pattern was no longer evident if a more stable reference group (subjects seropositive for two agents) was used instead of the relatively small reference group with zero or one seropositivity. We found no consistent pattern between IgG-seropositivity to several pathogens and inflammatory markers.

CONCLUSIONS

Based on serological evidence of various infectious agents, this study suggests that the aggregate number of persistent infections is not independently associated with an increased risk for CAD if control for confounding and use of a stable reference group are guaranteed.

Hepatitis A IgG seropositivity and coronary atherosclerosis assessed by angiography

BACKGROUND

Infectious agents, in particular intracellular pathogens that can establish long-term, persistent infection, may play an important role in atherogenesis. We tested the hypothesis that hepatitis A virus (HAV) could be associated with significant coronary artery disease.

METHODS

The possible association between HAV infection and angiographically proven coronary artery disease (CAD) was studied. Blood from 218 patients undergoing coronary angiography was tested for serum IgG antibodies to HAV.

RESULTS

Of the 218 patients, 178 (81.7%) had anti-HAV IgG antibodies. CAD prevalence was 66.3% in HAV seropositive and 57.5% in HAV seronegative patients (P=0.385). In contrast, the number of infectious pathogens to which an individual has been exposed correlates with CAD. Four or more of the six seromarkers tested for particular infections (HAV, Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus, influenza type A and type B) were positive in 48.8% of patients with CAD and in 31.2% of patients in patients without CAD (P=0.02).

CONCLUSIONS

This analysis demonstrated that HAV seropositivity is not a predictor of risk for CAD. HAV infection, therefore, seems not to be associated with CAD. The number of infectious agents to which an individual has been exposed ('infectious burden') correlates with CAD.

Helicobacter pylori, Chlamydia pneumoniae and myocardial infarction

BACKGROUND

Several epidemiological studies have suggested a positive association of coronary heart disease with both Helicobacter pylori and Chlamydia pneumoniae infection. The issue has been difficult to resolve because of the potential impact of several confounding factors, in particular, socioeconomic status for H. pylori and smoking for C. pneumoniae.

METHODS

A case-control study was carried out of 341 patients with a recent myocardial infarction (MI) and 831 community controls who had serology tests for H. pylori and C. pneumoniae (selected from a total study number of 1745 subjects). Individuals of Pacific Island or Maori ethnicity were excluded because they were infrequent.

RESULTS

H. pylori seropositivity was associated with increasing age (P < 0.001) and lower household income (P = 0.0003) but not with gender, smoking status or alcohol intake. H. pylori was associated with lower high-density lipoprotein cholesterol (P = 0.007) and a higher body mass index (P = 0.007). The overall seropositivity for H. pylori was 41.6% for patients with MI and 34.5% for age and sex-matched population controls. The odds ratio was 1.34 (95% confidence interval (CI): 1.00-1.80; P = 0.038) after adjusting for age and sex. C. pneumoniae seropositivity was significantly associated with male sex, younger age (P = 0.03) and smoking status (P = 0.004) but not associated with household income or any other measured risk factor for coronary heart disease. The overall seropositivity for C. pneumoniae was 51.2% for patients with recent MI and 43.5% for controls. After adjusting for age and sex, the odds ratio was 1.24 (95%CI: 0.95-1.62; P = 0.11). Subgroup analysis showed no clear pattern within different age groups. In particular, the odds ratio for H. pylori seropositivity in younger subjects (aged 35-49 years) was similar to the overall group (1.38; 95%CI: 0.83-2.29).

CONCLUSION

The association between H. pylori or C. pneumoniae seropositivity and coronary heart disease was significant but may not indicate a causal association.

Pulse-wave velocity and cardiovascular risk factors in subjects with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection has been reported to correlate with the onset of cardiovascular diseases. However, the relationship between H. pylori infection and the development of arteriosclerosis has not been fully investigated. We performed a cross-sectional study to clarify the possible role of H. pylori infection in the development of arteriosclerosis.

METHODS

The subjects were 996 cases who attended their annual medical check-up between April and August 2001. H. pylori infection status was determined by assaying serum anti-H. pylori immunoglobulin G antibodies. Total cholesterol, high-density lipoprotein cholesterol (HDLC), triglyceride, fasting blood glucose, hemoglobin A1c and leukocyte levels were determined. Arteriosclerotic parameters (systolic blood pressure (SBP), ankle brachial index (ABI) and pulse-wave velocity (PWV)) were measured non-invasively using an automatic device. The data for H. pylori-seropositive and -seronegative individuals were compared.

RESULTS

Five hundred and seventy-three subjects (57.5%) were H. pylori-seropositive. After adjustment for sex, age, body mass index, and smoking and drinking habits, the HDLC levels of the seropositive and seronegative groups differed markedly (55.0 vs 58.0 mg/dL, P < 0.0001). Although there were no differences between the overall adjusted SBP and ABI values, the PWV was higher in H. pylori-seropositive than -seronegative young (<39 years old) individuals (heart-carotid PWV: 632.2 vs 589.7 cm/s, P = 0.027). These differences tended to disappear with aging.

CONCLUSIONS

The degree of arterial stiffness in H. pylori-positive young subjects is higher than that in H. pylori-negative young subjects. However, no difference between the arterial stiffness values of H. pylori-seropositive and -seronegative elderly individuals was observed.

Role of Helicobacter pylori CagA+ strains and risk of adenocarcinoma of the stomach and esophagus

Infection with Helicobacter pylori (H. pylori), especially CagA+ strains, has been associated with an increased risk of noncardia gastric adenocarcinoma. The relationship with junctional cancer (adenocarcinomas of the esophagus and gastric cardia combined) has not been adequately investigated, although some studies have reported a reduced risk associated with H. pylori and CagA seroseropositivity. We investigated this question in a subset of cases and controls from a recently completed, large population-based case-control study of gastric and esophageal adenocarcinomas in Los Angeles County. Using established antigen-specific ELISAs, serum IgG antibodies to H. pylori whole-cell antigens (Helico-G) and CagA were measured in population controls (n = 356) and patients with incident esophageal adenocarcinoma (n = 80), gastric cardia cancer (n = 87) or distal gastric cancers (noncardia gastric adenocarcinoma) (n = 127). After controlling for demographic characteristics (age, gender, race, birthplace, education), smoking and body mass index, seropositivity for H. pylori was associated with a statistically significant increased risk of distal gastric cancer (adjusted odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.03, 3.32) but the risk of junctional cancer was not increased (adjusted OR = 1.26, 95% CI = 0.82, 1.94). The risk of junctional cancer was not changed when CagA and H. pylori were both considered, but the risk of distal gastric cancer was further increased. Subjects who were seropositive for both CagA and H. pylori compared to those who were seronegative for H. pylori showed a risk of 2.20 (95% CI = 1.13, 4.26) for distal gastric cancer and 0.86 (95% CI = 0.47, 1.59) for junctional cancer. Although tests for interaction between smoking and H. pylori were not statistically significant for junctional or distal gastric cancers, risk for both tumor types tended to be higher among current smokers who were also H. pylori seropositive. In conclusion, we find no evidence that infection with CagA+ strains of H. pylori reduces risk of esophageal and gastric cardia adenocarcinoma in this population. Our findings confirm the positive association between risk of distal gastric cancer and infection with H. pylori infection, especially CagA+ strains.

Increase of arterial thrombosis parameters in chronic Helicobacter pylori infection in mice

An animal model was developed to study arterial thrombosis and determine if animals infected with Helicobacter pylori behave differently after induction of direct damage to blood vessels. Twenty-one C56/BL6 mice inoculated with the "Sydney strain" of H. pylori and 19 uninfected animals were kept for 1 year before testing. Vascular lesions were induced to mesenteric arterioles (15-25 microm diameter) by Argon laser. The dynamic course of thrombus formation was continuously monitored by a video camera for 10 min. Three parameters were assessed: (1) the number of laser pulses required to induce thrombus formation, (2) the number of platelet emboli removed by the blood flow and, (3) the duration of embolization. Additionally, blood was tested for platelet aggregation, fibrinogen, and cell count. Of the parameters measured, statistical differences between infected and uninfected mice concerned the number of emboli formed (6.00+/-2.18 infected vs. 3.89+/-1.37 non-infected, p=.0006) and the duration of embolization (2.41+/-0.73 min infected vs. 1.47+/-0.61 min non-infected p>.0001). A significant difference was also found in the fibrinogen levels between infected and uninfected mice. Chronic infection of mice with H. pylori leads to increased platelet embolization after damage to arterioles. These results are in favor of the possible involvement of H. pylori infection in the acute phase of coronary heart disease (CHD).

Influenza A and B IgG seropositivity and coronary atherosclerosis assessed by angiography

Infectious agents, in particular intracellular pathogens that can establish long-term, persistent seropositivity, may play an important role in atherogenesis. The possible association between influenza type A and B infection and angiographically proven coronary artery disease (CAD) and the effect of the aggregate pathogen burden on CAD was studied by testing blood from 218 patients undergoing coronary angiography for serum IgG antibodies to influenza A and B, and for antibodies to four other pathogens (hepatitis A, Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus). This analysis demonstrates that although influenza (A and B) seropositivity represents no predictor of risk for CAD, infectious burden is independently associated with coronary atherosclerosis.

The association of seropositivity to Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus with risk of cardiovascular disease: a prospective study

OBJECTIVES

We sought to determine whether seropositivity to Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus (CMV) is an independent predictor of incident cardiovascular disease.

BACKGROUND

Recent reports have suggested that infections may contribute to risk of cardiovascular disease. However, prospective studies of these associations in a free-living population are lacking.

METHODS

We measured serum H. pylori IgG, C. pneumoniae IgG and IgA, and CMV IgG levels in Framingham Heart Study cohort participants. Blood samples were drawn during the 16th biennial examination cycle (1979 to 1982) from 1,187 participants free of cardiovascular disease (mean age 69 years) and stored at -20 degrees C. A pooled primary end point of myocardial infarction, atherothrombotic stroke, and coronary heart disease deaths was studied in relation to serology. Using a Cox model, hazard ratios (HR) and 95% confidence intervals (CI) were calculated, adjusting for age, gender, and established risk factors.

RESULTS

Seropositivity to H. pylori IgG, C. pneumoniae IgG, C. pneumoniae IgA, and CMV IgG was 60%, 45%, 11%, and 69%, respectively. During 10 years of follow-up, incident cardiovascular disease occurred in 199 participants (16.8%). In age- and gender-adjusted models, H. pylori IgG (HR 1.09, 95% CI 0.81 to 1.46), C. pneumoniae IgG (HR 0.91, 95% CI 0.68 to 1.20), C. pneumoniae IgA (HR 0.65, 95% CI 0.39 to 1.07), and CMV IgG (HR 0.84, 95% CI 0.62 to 1.12) were not associated with incident cardiovascular disease. These associations were further attenuated after adjustment for risk factors including body mass index, total and high-density lipoprotein cholesterol, diabetes mellitus, smoking, and hypertension. These estimates did not change for the individual components of cardiovascular disease, and seropositivity to more than one organism did not alter these risk estimates substantially.

CONCLUSIONS

In this elderly cohort, chronic H. pylori, C. pneumoniae, and CMV infections, as evidenced by seropositivity, were not associated with increased risk for cardiovascular disease. Additional studies are needed to determine the relations of chronic infections to cardiovascular disease risk in younger persons.

Cytotoxin-associated gene-A--positive Helicobacter pylori strains are associated with atherosclerotic stroke

BACKGROUND

It is uncertain whether Helicobacter pylori is associated with ischemic syndromes and whether this association is mediated by the induction of atherosclerosis. In this study, we tested the hypothesis that atherosclerotic stroke shows a selective association with virulent H pylori strains.

METHODS AND RESULTS

The seroprevalence of infection by H pylori and by strains bearing the cytotoxin-associated gene-A (CagA), a strong virulence factor, was assessed by ELISA in 138 patients with large-vessel stroke (group A), in 61 patients with cardioembolic stroke (group B), and in 151 healthy control subjects. The 3 groups had a similar socioeconomic status. Serum levels of C-reactive protein were also measured by ELISA. The prevalence of infection was 71% in group A, 63.9% in group B, and 70.2% in the control group (P=NS), whereas the prevalence of CagA-positive strains was higher in group A than in group B (42.8% versus 19.7%, respectively; odds ratio 3.04, 95% CI 1.43 to 6.49; P<0.001) and higher in group A than in the control group (42.8% versus 17.9%, respectively; odds ratio 4.3, 95% CI 2.12 to 8.64; P<0.001), after adjusting for main cardiovascular risk factors and social class. A trend toward a difference in C-reactive protein was observed between CagA-positive (2.00+/-3.43 [mean+/-SD] mg/dL) and CagA-negative (1.31+/-1.72 [mean+/-SD] mg/dL) patients (P=0.072, Mann-Whitney U test).

CONCLUSIONS

The association between H pylori and acute cerebrovascular disease seems to be due to a higher prevalence of more virulent H pylori strains in patients with atherosclerotic stroke.

Cross-reactivity of anti-CagA antibodies with vascular wall antigens: possible pathogenic link between Helicobacter pylori infection and atherosclerosis

BACKGROUND

Helicobacter pylori-CagA positive strains have been shown to be associated with atherosclerosis. However, the pathogenesis is still undetermined. The aim of this study was to determine whether anti-CagA antibodies cross-react with antigens of normal and atherosclerotic arteries.

METHODS AND RESULTS

Eight umbilical cord sections, 14 atherosclerotic artery sections, and 10 gastrointestinal tract sections were examined by immunohistochemistry using polyclonal anti-CagA antibodies. Five atherosclerotic and 3 normal artery samples were also lysed in ice-cold lysis buffer containing protease inhibitors and were immunoprecipitated using the same antibodies. Anti-CagA antibodies reacted with cytoplasm and nuclei of smooth muscle cells in umbilical cord and atherosclerotic vessel sections, cytoplasm of fibroblasts-like cells in intimal atherosclerotic plaques, and the cell membranes of endothelial cells. Anti-CagA antibodies also specifically immunoprecipitated 2 high molecular weight antigens of 160 and 180 kDa from both normal and atherosclerotic artery lysates.

CONCLUSIONS

Anti-CagA antibodies cross-react with antigens of both normal and atherosclerotic blood vessels. We speculate that the binding of anti-CagA antibodies to those antigens in injured arteries could influence the progression of atherosclerosis in CagA-positive H pylori-infected patients.

CD14 C(-260)-->T polymorphism, plasma levels of the soluble endotoxin receptor CD14, their association with chronic infections and risk of stable coronary artery disease

OBJECTIVES

We sought to investigate the association of CD14 genotype and plasma levels of soluble (s)CD14 with risk of stable coronary artery disease (CAD), chronic infections and sensitive markers of systemic inflammation.

BACKGROUND

It has been suggested that genetic variation of the CD14 receptor with increased CD14 gene expression might play a role in atherogenesis. A mechanistic link would consist in its contribution to the inflammatory response seen in this disease.

METHODS

We measured levels of sCD14 (microg/ml; ELISA) in 312 patients with angiographically proven CAD and stable angina pectoris, and in 477 age- and gender-matched healthy blood donors. CD14 genotype was determined by polymerase chain reaction. In addition, seropositivity to Chlamydia pneumoniae and Helicobacter pylori, a complete lipid profile and various sensitive systemic markers of inflammation were measured.

RESULTS

CD14 C(-260)-->T genotype was not independently associated with increased risk of CAD after multivariable adjustments (odds ratio [OR] 1.34; 95% confidence interval [CI] 0.84 to 2.16). However, sCD14 plasma levels were higher in subjects with TT genotype compared with those with CT or CC genotype (p = 0.005). Plasma levels were not different between cases and controls (4.2 +/- 1.3 microg/ml vs. 4.3 +/- 1.3 microg/ml, p = NS). In multivariable logistic regression, the OR for the presence of CAD was 1.11 (95% CI, 0.65 to 1.91) if the top quintile of the sCD14 distribution was compared with the bottom quintile. There was no consistent association between seropositivity to either C. pneumoniae or H. pylori, or both, and sCD14 levels and between sCD14 levels or CD14 genotype and the various markers of inflammation.

CONCLUSIONS

These results do not confirm an independent relationship between CD14 genotypes or plasma levels of sCD14 and risk of stable CAD in this population.

Cardiovascular risk factors in subjects with Helicobacter pylori infection

BACKGROUND

It has been proposed that Helicobacter pylori infection is related to cardiovascular disease, although this has not been fully investigated. The aim of this study was to investigate whether H. pylori infection is associated with cardiovascular risk factors.

SUBJECTS AND METHODS

One thousand six hundred and fifty people undergoing annual medical checks at Shimane Institute of Health Science between September 1998 and August 1999 were enrolled. Gender, age, body mass index, habitual smoking and drinking, systolic and diastolic blood pressure, serum level of total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDLC), blood glucose, leukocyte count and hemoglobin were compared between H. pylori seropositive and seronegative cases.

RESULTS

In H. pylori seropositive individuals, HDLC was significantly lower than that in seronegative individuals. After adjustment for possible confounding factors (gender, age, BMI, smoking and drinking habits), mean HDLC in H. pylori-seropositive and seronegative individuals were 56.1 and 58.2 mg/dl, respectively (p <.005). The percentage of the elderly (over 50 years old) individuals with HDLC < 35 mg/dl in H. pylori seropositive and seronegative groups were 7.4% and 4.7%, respectively (p <.001). In addition, the lower HDLC level was accompanied by an increased leukocyte count.

CONCLUSION

Long-term infection with H. pylori may have an important role in decreasing the serum HDLC concentration.

Influence of Helicobacter pylori infection and eradication on blood lipids and fibrinogen

BACKGROUND

An association between Helicobacter pylori infection and heart disease has been suggested. A potential mechanism may be inflammation-induced atherogenic changes of lipoproteins, but epidemiological studies have provided conflicting results.

METHODS

In a prospective multicentre study, 830 patients submitted for endoscopy and H. pylori testing were evaluated. Of the 686 H. pylori-positive patients, 487 received and 199 did not receive eradication treatment. Serum lipids and plasma fibrinogen were measured at baseline in all patients and 3 months later in those initially positive for H. pylori.

RESULTS

H. pylori had no influence on baseline lipid or fibrinogen levels. Increases in high-density lipoprotein cholesterol were observed in 368 patients who received eradication treatment and in 193 untreated patients: 0.06 mmol/L (P=0.000) and 0.07 mmol/L (P=0.009), respectively. Similar minor increases in total cholesterol and triglycerides occurred in both groups. Lipid changes were related to symptom relief and a reduction in smoking. Eradication therapy was associated with a minor decrease in plasma fibrinogen irrespective of the resolution of infection.

CONCLUSIONS

H. pylori has no influence on blood lipids or fibrinogen. Both the eradication of infection and symptomatic treatment without eradication are associated with minor lipid changes related to symptom relief and lifestyle modifications. Thus, the inflammatory changes associated with H. pylori are unlikely to affect lipoprotein or fibrinogen metabolism.