Pylori-positive Participants Research Articles

A large randomised controlled intervention trial to prevent gastric cancer by eradication of Helicobacter pylori in Linqu County, China: baseline results and factors affecting the eradication

ObjectiveTo clarify the full range of benefits and adverse consequences of Helicobacter pylori eradication as a strategy for gastric cancer prevention, the community-based intervention trial was launched in Linqu County,...

Does H. pylori Colonization Impact Basal Metabolic Rate?

Introduction: Ghrelin is produced mainly by the stomach and may influence energy expenditure. H. pylori colonization is associated with reduced circulating ghrelin levels. We hypothesized that H. pylori colonization impacts resting metabolic rate (RMR). The aims of this study were to: 1.) evaluate the reproducibility of RMR measurements via a hand-held indirect calorimeter in healthy young adults, 2.) compare the RMR between individuals with and without H. pylori colonization, and 3.) analyze the change in RMR after H. pylori eradication. Methods: For the validation aim of the study, 7 healthy volunteers were enrolled and evaluated for demographic as well as clinical information. The MedGem indirect calorimeter device was used for all measurements. Weekly-standardized RMR and oxygen consumption (VO2) measurements were obtained for 4 consecutive weeks. For the second and third aims, 44 participants were evaluated at baseline for H. pylori status. All H. pylori-positive participants were treated with standard eradication regimens. RMR data was collected at baseline and subsequent follow-up visits (6 weeks, 3 months, and 6 months). Results: For the validation aim of the study, the pairwise correlations for weekly RMR measurements were all higher than 0.70, and the intra-class correlation coefficient (ICC) of the multiple measurements of RMR was 0.987 over 4 weeks. For the second and third aims, 17% of all participants were male, and the mean age was 24.57 years. The mean baseline BMI for all participants was 24.03. The mean baseline RMR for the H. pylori-negative and positive participants was 1297.8 and 1421.4, respectively. There was no significant difference in baseline RMR by H. pylori status (p=0.631). The absolute mean change in RMR from baseline to 6 weeks post treatment was greater for the H. pylori-positive group than the negative group (18.6 vs. -2.5), although not statistically significant. Similarly, the mean change in RMR from baseline to 3 months post treatment was greater for the H. pylori-positive group than the negative group (75.0 vs. 62.5). For the H. pylori-positive group, there was a significant difference between the mean RMR at baseline compared to the 3-month follow-up (p=0.034). Conclusion: Measurement of resting metabolic rate via a hand-held indirect calorimeter in young healthy adults is reproducible. H. pylori-colonization, as well as eradication, impacts RMR. Further assessment of the long-term metabolic consequences of H. pylori eradication should be undertaken.

Prevalence of Helicobacter pylori infection and its relation with body mass index in a Chinese population.

Helicobacter pylori infection is highly prevalent worldwide. The association between obesity and H. pylori infection is controversial in the literature. This study aims to investigate the prevalence of H. pylori infection and its relation with body mass index (BMI) in a Chinese population. A cross-sectional study was performed among adults who underwent health checkups at the First Affiliated Hospital, College of Medicine, Zhejiang University in 2013. The prevalence of H. pylori infection was examined by (13)C urea breath tests, and the association between prevalence of H. pylori infection and BMI was analyzed. Of the 8820 participants enrolled, 3859 (43.8%) were positive for H. pylori infection. H. pylori-positive participants had a more unfavorable metabolic profile than H. pylori-negative participants. Overweight/obese participants showed a higher prevalence of H. pylori infection than that of lean participants, and a positive linear correlation between BMI and prevalence of H. pylori infection was observed. Both unadjusted and adjusted analysis revealed that BMI was significantly associated with risk factors of H. pylori infection. Our results showed that BMI was significantly and positively associated with H. pylori infection, and a high BMI was associated with an increased risk of the infection.

Comparison of Fecal Occult Blood Tests for Colorectal Cancer Screening in an Alaska Native Population With High Prevalence ofHelicobacter pyloriInfection, 2008–2012

IntroductionAlaska Native colorectal cancer (CRC) incidence and mortality rates are the highest of any ethnic/racial group in the United States. CRC screening using guaiac-based fecal occult blood tests (gFOBT) are not recommended for Alaska Native people because of false-positive results associated with a high prevalence of Helicobacter pylori-associated hemorrhagic gastritis. This study evaluated whether the newer immunochemical FOBT (iFOBT) resulted in a lower false-positive rate and higher specificity for detecting advanced colorectal neoplasia than gFOBT in a population with elevated prevalence of H. pylori infection.MethodsWe used a population-based sample of 304 asymptomatic Alaska Native adults aged 40 years or older undergoing screening or surveillance colonoscopy (April 2008–January 2012).ResultsSpecificity differed significantly (P < .001) between gFOBT (76%; 95% CI, 71%–81%) and iFOBT (92%; 95% CI, 89%–96%). Among H. pylori-positive participants (54%), specificity of iFOBT was even higher (93% vs 69%). Overall, sensitivity did not differ significantly (P = .73) between gFOBT (29%) and iFOBT (36%). Positive predictive value was 11% for gFOBT and 32% for iFOBT.ConclusionThe iFOBT had a significantly higher specificity than gFOBT, especially in participants with current H. pylori infection. The iFOBT represents a potential strategy for expanding CRC screening among Alaska Native and other populations with elevated prevalence of H. pylori, especially where access to screening endoscopy is limited.

Disease manifestations of Helicobacter pylori infection in Arctic Canada: using epidemiology to address community concerns

ObjectivesHelicobacter pylori infection, linked to gastric cancer, is responsible for a large worldwide disease burden. H pylori prevalence and gastric cancer rates are elevated among indigenous Arctic communities, but implementation...

Effects of Polymorphisms of Innate Immunity Genes and Environmental Factors on the Risk of Noncardia Gastric Cancer

PurposeIncreasing evidence suggests that polymorphisms in innate immunity genes are associated with Helicobacter pylori-induced inflammation and may influence susceptibility in developing noncardia gastric cancer. Therefore, we investigate the effect of polymorphisms of innate immunity genes and interactions with environmental factors in the Korean population.Materials and MethodsWe genotyped four polymorphisms of TLR2 (rs1898830), TLR4 (rs10983755 and rs10759932), and CD14 (rs2569190) in a case-control study of 487 noncardia gastric cancer patients and 487 sex- and age-matched healthy controls. Polytomous logistic regression models were used to detect the effects of genetic polymorphisms and environmental factors, which were stratified by the histological type of gastric cancer.ResultsTLR4 rs10983755 A carriers were found to have higher risk of intestinal-type noncarida gastric cancer than G homozygotes (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.01 to 1.97), but other genetic variants showed no association with the risk of noncardia gastric cancer. Among H. pylori-positive participants, smokers carrying TLR4 rs10983755 A had a higher risk of intestinal-type gastric cancer than nonsmoking TLR4 rs10983755 G homozygotes (OR, 4.28; 95% CI, 2.12 to 8.64). In addition, compared with tap water, other drinking water sources during childhood were found to be associated with the elevated risk of intestinal-type gastric cancer, and these associations were slightly stronger among TLR4 rs10983755 A carriers.ConclusionThe genetic polymorphisms of innate immunity genes are associated with the development of intestinal-type noncardia gastric cancer and these associations may differ in accordance to an exposure to certain environmental factors.

Helicobacter pylori incidence and re-infection in the Aklavik H. pylori Project

BackgroundThe Aklavik H. pylori Project (AHPP) (www.canhelpworkinggroup.ca) is a community-driven project examining Helicobacter pylori infection and its influence on health in a diverse Aboriginal community in the Northwest Territories. Initial research revealed that 58% of 333 participants who underwent a urea breath test (UBT) between 2007 and 2010 were H. pylori-positive. From 2008 to 2010, we offered treatment to H. pylori-positive participants and 113 consented to this treatment.ObjectiveWe estimated H. pylori incidence in AHPP participants who initially tested negative and the re-infection frequency in initially positive participants who were successfully treated to clear the infection.MethodsParticipants who were initially H. pylori-negative or negative after treatment during 2008–2010 were eligible for inclusion. From November 2011 to June 2012, participants were offered a UBT and the samples were analyzed using infrared spectroscopy (IRIS). Participants with a positive test result were classified as new cases for estimating incidence among participants testing negative at baseline and re-infection among those successfully treated for H. pylori infection.ResultsAmong 38 initially negative participants, follow-up UBT showed that 33 remained negative, 3 were positive, and 2 had uncertain status. The estimated incidence proportion during the follow-up period was 8.3% (95% CI: 1.8–22.0%). Among 43 participants with a negative post-treatment UBT, 41 remained negative and 2 were positive. The estimated re-infection proportion during the follow-up period was 4.7% (95% CI: 0.6–16.0%). The frequency of new cases was similar in males and females. Aboriginal participants had a combined re-infection/incidence rate of 2.4% per year (95% CI: 0.8–5.9% per year). All 9 non-Aboriginal participants remained free from infection throughout the study period, as did all 23 participants aged 55 years and above.ConclusionsThe AHPP has substantially reduced the burden of infection in Aklavik since 2008. Continued monitoring, treatment, community engagement and knowledge translation activities are needed to ensure a lasting benefit of the project.

Plasma ghrelin isoforms and gastric ghrelin O-acyltransferase expression are influenced by Helicobacter pylori status

ObjectiveHelicobacter pylori is known to affect the host’s nutritional status. This study was performed to elucidate the relationship between H. pylori status and the dynamics of the ghrelin system, in the context of ghrelin O-acyltransferase (GOAT) expression. MethodsWe conducted a clinical study of 30 subjects focusing on the following points: 1) the effects of H. pylori infection on the concentrations of circulating ghrelin isoforms and on ghrelin and GOAT mRNA expression in the gastric mucosa, and 2) the effects of H. pylori eradication on the same parameters. ResultsThe plasma acyl-ghrelin and desacyl-ghrelin concentrations of 16 H. pylori positive participants were significantly lower than those of 14 H. pylori negative controls. The acyl-ghrelin/desacyl-ghrelin ratio was not significantly different between the H. pylori positive and H. pylori negative participants. The levels of ghrelin and GOAT mRNA in the gastric mucosa were significantly lower in the H. pylori positive participants than in the H. pylori negative controls. In 11 subjects in whom H. pylori eradication was successful, their plasma acyl-ghrelin levels tended to increase after H. pylori eradication, but the difference was not significant; however, their plasma desacyl-ghrelin levels were significantly reduced. Although gastric ghrelin mRNA expression increased significantly after H. pylori eradication, gastric GOAT mRNA expression tended to increase but was not significantly altered. ConclusionH. pylori status might affect the host’s nutritional status through changes in the plasma levels of ghrelin isoforms and the gastric expression levels of ghrelin and GOAT mRNA.

Serum pepsinogen and Helicobacter pylori infection—a Japanese population study

The decreased ratio of serum pepsinogen (PG) I and II has good correlation with the presence of atrophic gastritis. A total of 1,540 residents aged 30-89years were enrolled into this study to investigate which serum PG level of residents with Helicobacter pylori infection would represent an adjunct to the diagnosis and progression of atrophic gastritis. All participants received esophagogastroduodenoscopy. Serum antibody to H. pylori (anti-H. pylori) was measured by an enzyme-linked immunosorbent assay (ELISA). Serological atrophic gastritis was defined as serum PG I isozyme level ≤70ng/ml and a PG I/II ratio of ≤3.0. Of the 1,540 participants, 923 (59.9%) were positive for anti-H. pylori. Serological atrophic gastritis was found significantly more often in anti-H. pylori-positive participants (40.8%) than in anti-H. pylori-negative participants (7.9%) (p ≤ 0.0001). The endoscopic findings of anti-H. pylori-positive participants with serological atrophic gastritis were significantly more frequent by 4.06 times for atrophic gastritis (p ≤ 0.0001) than anti-H. pylori-negative participants without serological atrophic gastritis. Eight anti-H. pylori-positive participants were diagnosed with gastric cancer, but no cancer was found in anti-H. pylori-negative participants without serological atrophic gastritis. Serum PG testing is clinically useful for the prediction of gastric lesions in H. pylori-infected persons.

Abstract A64: Effects of genetic polymorphisms of innate immunity genes on the noncardia gastric cancer risk

Abstract Background and Objective: Increasing evidence suggests that polymorphisms in innate immunity genes are associated with Helicobacter pylori (H. pylori)-induced inflammation and may influence susceptibility to developing noncardia gastric cancer. Therefore, we investigated the effect of polymorphisms of TLR2, TLR4, and CD14, their combination and interaction with environmental factors on the noncardia gastric cancer risk in a Korean population. Methods: We genotyped four polymorphisms in three genes (TLR2, rs1898830 A&amp;gt;G; TLR4, rs10759932 T&amp;gt;C, rs10983755 A&amp;gt;G; CD14, rs2569190 T&amp;gt;C) in a case-control study of 487 noncardia gastric cancer patients and 487 sex- and age-matched healthy controls. Multiple logistic regression models were used to detect the effects of genetic polymorphisms and environmental factors, which was stratified by the histological type of gastric cancer. Results: TLR4 rs10983755 variant allele carriers were found to have a higher risk of intestinal type gastric cancer than homozygous wild-type carriers (OR [95% CI] = 1.40 [1.01–1.96], P = 0.046). Other genetic variants did not show any association with noncardia gastric cancer risk. When we examined the combined effect with other polymorphisms, the increased risk of intestinal type gastric cancer among TLR4 rs10983755 variant allele carriers compared to wild-type homozygous carriers were observed only among homozygous wild-type carriers of TLR2 rs1898830 (OR [95% CI] = 1.97 [1.24–3.12], P = 0.004) or CD14 rs2569190 (OR [95% CI] = 1.95 [1.31–2.91], P = 0.001). In addition, the effect of TLR4 rs10983755 variant allele on intestinal type gastric cancer was stronger among H. pylori-positive participants who are under 55 years old, smoke tobacco and drink alcoholic beverages. Conclusion: These results suggest that the genetic polymorphisms of these innate immunity genes are associated with the development of H. pylori-associated noncardia gastric cancer. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A64.

Helicobacter pylori infection and circulating ghrelin levels - A systematic review

BackgroundThe nature of the association between ghrelin, an orexigenic hormone produced mainly in the stomach, and Helicobacter pylori (H pylori), a bacterium that colonises the stomach, is still controversial. We examined available evidence to determine whether an association exists between the two; and if one exists, in what direction.MethodsWe reviewed original English language studies on humans reporting circulating ghrelin levels in H pylori infected and un-infected participants; and circulating ghrelin levels before and after H pylori eradication. Meta-analyses were conducted for eligible studies by combining study specific estimates using the inverse variance method with weighted average for continuous outcomes in a random effects model.ResultsSeventeen out of 27 papers that reported ghrelin levels in H pylori positive and negative subjects found lower circulating ghrelin levels in H pylori positive subjects; while 10 found no difference. A meta-analysis of 19 studies with a total of 1801 participants showed a significantly higher circulating ghrelin concentration in H pylori negative participants than in H pylori positive participants (Effect estimate (95%CI) = -0.48 (-0.60, -0.36)). However, eradicating H pylori did not have any significant effect on circulating ghrelin levels (Effect estimate (95% CI) = 0.08 (-0.33, 0.16); Test for overall effect: Z = 0.67 (P = 0.5)).ConclusionsWe conclude that circulating ghrelin levels are lower in H pylori infected people compared to those not infected; but the relationship between circulating ghrelin and eradication of H pylori is more complex.

Bioavailability of Vitamins E and C: Does Helicobacter pylori Infection Play a Role?

Background: While the association between bioavailability of vitamins E and C and Helicobacter pylori infection has been extensively researched in gastritis and gastric cancer patients, little is known about this relationship in asymptomatic adults. Aim: To investigate the effect of H. pylori infection on bioavailability of vitamins E and C in asymptomatic adults. Methods: Volunteers from the University of Toronto, aged 18–45 years, were screened, for their H. pylori infection status. H. pylori-negative (n = 32) and asymptomatic H. pylori-positive (n = 27) participants received vitamin C (500 mg) and vitamin E (400 IU) supplements daily for 28 days. Plasma vitamins C, E and thiols concentrations were assessed before (baseline) and after supplementation. Results: Postsupplementation plasma levels of vitamin C and E were significantly higher than presupplementation levels in both groups. Yet, changes in plasma vitamins E and C were not significantly different between the two groups [vitamin C (µmol/l): 13.97 ± 16.86 vs. 20.87 ± 27.66, p > 0.05; vitamin E (µmol/l): 15.52 ± 9.4 vs. 14.47 ± 15.77; p > 0.05 for H. pylori-negative and H. pylori-positive groups, respectively]. In addition, no significant difference was found in plasma thiols levels between groups (p > 0.05). Conclusion: These findings suggest that H. pylori does not influence antioxidants bioavailability in its asymptomatic stages of infection until a factor or combination of factors triggers the inflammation cascade which may lead to increased oxidative stress and possibly reduced bioavailability of vitamins E and C.

Increased number of methylated CpG islands correlates with Helicobacter pylori infection, histological and serological severity of chronic gastritis

Promoter hypermethylation of tumor suppressor genes is one of the major events in gastric carcinogenesis. Promoter hypermethylation is also present in non-neoplastic gastric epithelium as age-related phenomenon and some reports suggest the potential association between promoter hypermethylation and Helicobacter pylori infection. Here, we examined whether methylation of multiple promoter CpG islands would occur by H. pylori infection and correlate with histological or serological severity of chronic gastritis. One hundred and ninety-one gastric mucosa samples were obtained by endoscopy. The promoter methylation status of the p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific-polymerase chain reaction. The degree of gastritis in the antrum was assessed according to the updated Sydney system in 150 participants. The pepsinogen (PG) I/II ratio was calculated based on the data of serum PG I and PG II levels measured by radioimmunoassay in 54 selected cases. CpG island methylation was found in 32.5% for p14, 35.1% for p16, 43.5% for DAP-kinase and 36.1% for CDH1, whereas non, 1, 2, 3, and all methylation of four promoter CpG sites were present in 46 (24.1%), 59 (30.9%), 46 (24.1%), 30 (15.7%), and 10 (5.2%) participants, respectively. A strong association between the increased number of methylated CpG islands and H. pylori infection was observed (P<0.0001). An increased number of methylated CpG islands was also associated with severity of neutrophil infiltration (P<0.0001), mononuclear cell infiltration (P<0.0001) and atrophy (P=0.0021) in all, and severity of neutrophil infiltration (P=0.0177) and mononuclear cell infiltration (P=0.0004) in H. pylori-positive participants. An increased number of methylated CpG islands correlated with lower PG I/II ratio in all (P=0.0105) and H. pylori-infected participants (P=0.074). Multiple promoter CpG islands would be methylated by H. pylori infection, and an increased number of methylated CpG sites correlate with histological and serological severity of chronic gastritis.

Opposing Risks of Gastric Cardia and Noncardia Gastric Adenocarcinomas Associated With Helicobacter pylori Seropositivity

Colonization with Helicobacter pylori is a risk factor for gastric adenocarcinoma, but the magnitude of this association and its relationship to anatomic location of the cancer, duration of follow-up, age at diagnosis, histologic subtype, and H. pylori strain differences are less clear. We conducted a prospective nested case-control study of H. pylori serology to address these questions. Case and control subjects were selected from the 29,133 50- to 69-year-old males recruited into the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. At baseline, detailed demographic data and a serum sample were collected. From 1985 to 1999, 243 incident cases of gastric adenocarcinoma were diagnosed in cohort members. Serum samples from 234 case subjects (173 with noncardia gastric cancers and 61 with gastric cardia cancers) and 234 age-matched control subjects were assayed for antibodies against H. pylori whole-cell and CagA antigens. We fit conditional logistic regression models to estimate the unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association of H. pylori seropositivity, defined as seropositivity to either whole-cell or CagA antigens, with noncardia gastric and gastric cardia cancers. All statistical tests were two-sided. H. pylori seropositivity was strongly associated with the risk of noncardia gastric cancer (adjusted OR = 7.9, 95% CI = 3.0 to 20.9) but was inversely associated with the risk of gastric cardia cancer (adjusted OR = 0.31, 95% CI = 0.11 to 0.89). H. pylori seropositivity rates did not vary statistically significantly by length of follow-up, age at diagnosis, or histologic subtype. A calculation of rates showed that the absolute risks of noncardia gastric and cardia gastric adenocarcinomas in the H. pylori-positive participants of this cohort would be 63 and 12 per 100,000 person-years, respectively, whereas corresponding rates in H. pylori-negative participants would be 8 and 37 per 100,000 person-years, respectively. H. pylori is a strong risk factor for noncardia gastric cancer but is inversely associated with the risk of gastric cardia cancer. These findings bolster the hypothesis that decreasing H. pylori prevalence during the past century may have contributed to lower rates of noncardia cancer and higher rates of cardia cancer in Western countries.

Clinical Significance and Outcome of Gastric Mucosal Erosions: A Long-Term Follow-Up Study

Our purpose was to evaluate the long-term clinical significance of gastric erosions. A series of 117 patients with gastric erosions without peptic ulcer disease, and matched controls were studied in 1974-1979. All available subjects were reinvestigated 17 years later, including detailed clinical history and laboratory analysis. At follow-up, erosions were still more prevalent (39%; 20/50) in the erosion group than in the controls (11; 7/66). In Helicobacter pylori-positive participants, peptic ulcer or a scar was more common in the erosion group (17%; 9/52) than in controls (5%; 3/66). Overall malignancy rate was higher in controls (15%; 17/117) than in erosion group (5%; 6/117; P = .025), but no other differences were seen between the groups or related with current erosion. We conclude that a significant proportion of gastric erosions are chronic or recurrent but mostly without serious complications. However, H. pylori-positive patients with erosions have significant risk to develop a peptic ulcer.

Follow-Up Care After a Diagnosis of Helicobacter pylori Infection in an Asian Immigrant Cohort

To study the rate at which Helicobacter pylori infection is treated in an immigrant cohort after diagnosis by esophagogastroduodenoscopy (EGD). Gastric cancer is the second leading cause of cancer death worldwide, and is especially prevalent in East Asia; immigrants from this part of the world remain at higher risk. Infection with H. pylori is a known risk factor for gastric cancer. There have been no studies of completion of H. pylori treatment in immigrant populations. Prospective cohort study of East Asian immigrants diagnosed with H. pylori infection who underwent EGD in a gastric cancer screening protocol. Our primary outcome was self-report or chart evidence of completion of treatment of H. pylori. Sixty-eight of the 126 participants (54%) tested positive for H. pylori infection on EGD. Forty-nine (72%) were seen for a follow-up visit at one of the clinics involved in the study. According to clinic records, 39 of these 49 participants (57% of all H. pylori-positive participants) were prescribed treatment. Only 31 participants (46%) completed treatment. Of possible explanatory factors, only having a "regular doctor" was significantly associated with treatment completion (odds ratio=5.6; 95% confidence interval, 1.2-25.0). In a sample of Asian immigrants, the rate of treatment of H. pylori infection, a potentially modifiable risk factor, was lower than expected. Having a "regular doctor" appeared to increase the likelihood of receiving appropriate follow-up care.