A study of incidence and relationship of intestinal metaplasia of gastric antrum and gastric metaplasia of duodenum in patients with nonulcer dyspepsia

Tobacco smoking and intestinal metaplasia: Systematic review and meta-analysis

BACKGROUND

The evaluation of specific risk factors for early endpoints in the gastric carcinogenesis pathway may further contribute to the understanding of gastric cancer aetiology.

AIMS

To quantify the relation between smoking and intestinal metaplasia through systematic review and meta-analysis.

METHODS

Articles providing data on the association between smoking and intestinal metaplasia were identified in PubMed(®), Scopus(®) and Web of Science™, searched until April 2014, and through backward citation tracking. Summary odds ratio estimates and 95% confidence intervals were computed using the DerSimonian and Laird method. Heterogeneity was quantitatively assessed using the I(2) statistic.

RESULTS

A total of 32 articles were included in this systematic review and 19 provided data for meta-analysis. Smoking was defined as ever vs. never (crude estimates, six studies, summary odds ratio=1.54, 95% confidence interval: 1.12-2.12, I(2)=67.4%; adjusted estimates, seven studies, summary odds ratio=1.26, 95% confidence interval: 0.98-1.61, I(2)=65.0%) and current vs. non-smokers (crude estimates, seven studies, summary odds ratio=1.27, 95% confidence interval: 0.88-1.84, I(2)=73.4%; adjusted estimates, two studies, summary odds ratio 1.49, 95% confidence interval: 0.99-2.25, I(2)=0.0%).

CONCLUSION

The weak and non-statistically significant association found through meta-analysis of the available evidence does not confirm smoking as an independent risk factor for intestinal metaplasia.

Effect of smoking on gastric histology in Helicobacter pylori-positive gastritis

OBJECTIVE

Smoking and Helicobacter pylori are both deleterious to the gastric and duodenal mucosa. Smoking also seems to modify inflammation in H. pylori infection. The aim of this study was to investigate the relationship between smoking and H. pylori in the Finnish population.

MATERIAL AND METHODS

We analysed the effect of smoking on gastric inflammation, humoral response to H. pylori and peptic ulcer disease among 318 Finnish H. pylori-positive patients (age 18-75 years; 73 smokers). Gastric histology was evaluated according to the updated Sydney system.

RESULTS

Smoking affected neither antral inflammation nor atrophy. In the gastric body, smokers showed milder chronic and neutrophilic inflammation and less atrophy (4% versus 17%, p=0.004). In smokers, H. pylori infiltration was denser in the atrium (mean 2.14 versus 1.87, p=0.02) but less dense in the body (mean 1.55 versus 1.84, p=0.003). Smoking thus seems to decrease inflammation in the gastric body and to delay atrophic changes in the gastric body. Subsequently, the prevalence of duodenal ulcers increased (32% versus 11%, p<0.001), but not the prevalence of gastric ulcers. Smoking also reduced serum IgG antibody titres against H. pylori (mean 8535 versus 5587, p=0.002) and their percentage decrease after successful eradication, possibly affecting serological diagnostic efficacy. Smokers were younger than non-smokers, but when age was taken into account, the differences remained the same.

CONCLUSIONS

In H. pylori-positive gastritis, smoking reduced inflammation and atrophy in the gastric body as well as humoral response to H. pylori.

Smoking, Helicobacter pylori virulence, and type of intestinal metaplasia in Portuguese males

High-virulence Helicobacter pylori strains and smoking increase the risk of gastric precancerous lesions. However, its association with specific types of intestinal metaplasia has been poorly studied. We aimed to quantify the association between different types of intestinal metaplasia (complete, incomplete, and mixed) and these two risk factors. Male volunteers (n = 227) underwent an upper digestive endoscopy and completed symptoms and lifestyle questionnaires. A histologic diagnosis was assigned based on the lesions found in any of the biopsy specimens (antrum, body, or incisura). H. pylori vacA and cagA were directly genotyped by multiplex PCR and reverse hybridization. Each participant's smoking status at the time of endoscopy was assessed. Logistic and multinomial logistic regression models were fitted (including H. pylori virulence, smoking, age, and education as independent variables) using normal/chronic nonatrophic gastritis as the reference category. Compared with never smokers infected with low-virulence strains, the risk of intestinal metaplasia was increased in subjects infected with high-virulence strains [odds ratio (OR), 5.74; 95% confidence interval (95% CI), 1.68-19.63] and in ever smokers (OR, 3.54; 95% CI, 1.30-9.61). In ever smokers infected with high-virulence H. pylori strains, the risk of intestinal metaplasia was further increased (OR, 8.61; 95% CI, 3.07-24.17). Infection with high-virulence strains significantly increased the risk of incomplete (OR, 9.81; 95% CI, 2.39-40.31) and mixed (OR, 3.28; 95% CI, 1.51-7.14) intestinal metaplasia. Complete (OR, 2.82; 95% CI, 1.01-7.88) and mixed (OR, 2.97; 95% CI, 1.12-7.84) intestinal metaplasia were more frequent among ever smokers. High-virulence H. pylori strains and smoking are differentially associated with the complete and incomplete types of intestinal metaplasia, suggesting divergent pathways in gastric carcinogenesis.

Environmental Factors in Helicobacter pylori-Related Gastric Precancerous Lesions in Venezuela

Although Helicobacter pylori (HP) infection has been acknowledged to play an etiological role in gastric carcinogenesis, its relatively weak association particularly in developing countries suggests critical roles of cofactors. Among a population with an extremely high prevalence of HP infection (≈95%) in Venezuela, we examined the relationship of household characteristics, smoking, alcohol drinking, dietary consumption, and plasma nutrient levels with the prevalence of three different stages of gastric precancerous lesions, chronic atrophic gastritis (AG; n = 337), intestinal metaplasia (IM; n = 551), and dysplasia (n = 157), in comparison with those without any of these lesions (n = 1154). Length of refrigerator use was marginally inversely associated with the prevalence of the precursor lesions studied. The association was most pronounced for AG followed by dysplasia. On the other hand, smoking status was a significant predictor for IM and dysplasia. Those smoking ≥10 cigarettes/day had 1.8-fold risk of IM and 3.6-fold risk of dysplasia compared with never smokers. There were no associations with alcohol consumption. When six food groups known to be associated with stomach cancer risk in Venezuela were tested, the prevalence of these lesions progressively increased with increasing starchy vegetable consumption and decreasing fresh fruit/fruit juice consumption. The association with fruits was more evident for dysplasia and AG and that with starchy vegetables for IM and AG. However, there were no inverse associations with plasma antioxidant vitamins. These findings offer important public health implications in preventing progression of HP-associated gastric precancerous lesions in high-risk populations.

Effect of lifestyle, smoking, and diet on development of intestinal metaplasia in H. pylori-positive subjects

OBJECTIVES

This study aimed to evaluate the influence of environmental and sociodemographic factors and the effect of smoking, alcohol, and dietary habits on the risk of gastric intestinal metaplasia (IM) in Helicobacter pylori-infected subjects.

METHODS

The investigation was based on 2598 consecutive volunteer blood donors tested for the presence of antibodies against H. pylori from March 1995 to March 1997. Endoscopy with multiple biopsies was offered to all H. pylori-positive, symptomatic subjects. The presence or absence of IM was diagnosed by gastric biopsies. A serologically H. pylori-positive subject with gastric IM was defined as a case, whereas serologically H. pylori-positive subjects without IM were used as controls. All patients answered a detailed questionnaire collecting sociodemographic characteristics and smoking, alcohol drinking, and dietary habits. Odds ratios (ORs) and their 95% CIs were estimated by unconditional logistic regression, including terms for age and sex, to assess the association between the data collected and IM.

RESULTS

Three hundred forty-four subjects with serological H. pylori infection and upper-GI symptoms underwent GI endoscopy, during which biopsies were taken for histological diagnosis. Histology revealed metaplasia in 74 subjects (21.5%). Incomplete IM was found in 37.8% of these cases. No significant associations were found between IM and anthropometric or sociodemographic factors. There was a significant association between age and IM (chi2 for trend, 6.67; p value, 0.009). Current smokers of over 20 cigarettes per day had a 4-fold risk of IM (OR, 4.75, 95% CI, 1.33-16.99). A 2-fold increased risk was found for high butter consumers (OR, 2.17; 95% CI, 1.14-4.11). No significant specific associations were found between the variables studied and complete or incomplete IM.

CONCLUSIONS

This study found that smoking and high butter consumption may increase the risk of having gastric IM in H. pylori-positive subjects.

Duodenogastric reflux is associated with antral metaplastic gastritis

BACKGROUND

It has long been suspected that duodenogastric reflux plays a role in the pathogenesis of intestinal metaplasia (IM), although recent studies have demonstrated a close association between Helicobacter pylori infection and gastroduodenal diseases, including IM. The objective of this study was to investigate the relation among IM and duodenogastric reflux, H pylori infection, and smoking.

METHODS

Subjects with "marked" characteristics of IM, all with extensive prepyloric distribution at endoscopy that was confirmed histologically, were studied as an IM group (27 men, 26 women; mean age, 64 years). A control group was comprised by subjects without characteristics of IM (29 men, 28 women; mean age, 63 years). Fasting pH, total bile acid concentration, and ammonia concentration were measured in the gastric juice of all participants. Histologic examination endoscopic biopsy specimens were evaluated histologically. H pylori infection was determined by serum antibody and urease testing, and by histology. Serum gastrin and pepsinogen concentrations, and gastric emptying time were measured. Dietary, drinking, and smoking habits were recorded. Comparisons were made between groups and analyzed statistically.

RESULTS

The pH and total bile acid concentrations were significantly higher in the IM group than the control group (p < 0.01). No significant difference in H pylori infection was found between the IM and control group. Smoking was associated with IM (odds ratio [OR], 15.74; 95% CI, 3.96 to 62.50).

CONCLUSIONS

A high pH and total bile acid concentration and smoking were associated with "marked" IM, suggesting that these factors may play a role in the development of IM.

Heterotopic gastric tissue in the duodenal bulb

Heterotopic gastric tissue in the duodenal bulb is a rare congenital lesion. Its prevalence has been reported to be 0.5-2%. It must be differentiated from gastric metaplasia of the duodenal bulb because the two entities have different clinical implications. During one year, we found three cases of gastric heterotopia of the duodenal bulb. In one of the cases, active acid-secreting gastric mucosa was documented by performing the pentagastrin Congo red dye test. The differences between gastric heterotopia of the duodenal bulb and gastric metaplasia of the duodenal bulb have been discussed.

Circadian gastric acidity in Helicobacter pylori positive ulcer patients with and without gastric metaplasia in the duodenum

BACKGROUND

The presence of gastric metaplasia allows helicobacter pylori to colonise the duodenum and this condition is thought to be acquired as a response to acid hypersecretion. This functional disorder, however, is present only in a subgroup of duodenal ulcer patients and, in addition, surface gastric metaplasia has been frequently found in the proximal duodenum of normal subjects and patients with non-ulcer dyspepsia, who cannot be certainly considered as acid hypersecretors.

AIMS

To clarify the role of acid in inducing gastric type epithelium in the duodenum. This study aimed at assessing whether the pattern of circadian gastric acidity differs between H pylori positive duodenal ulcer patients with and without duodenal gastric metaplasia.

PATIENTS

Seventy one patients with duodenal ulcer confirmed by endoscopy and who were found to be positive for H pylori infection by histology on antrum biopsy specimens were enrolled into this study.

METHODS

Gastric type epithelium in the duodenum was found in 49 of 71 ulcer patients (69%). Continuous 24 hour gastric pH metry was performed in 50 healthy subjects and in the two subgroups of duodenal ulcer patients with and without gastric metaplasia in the duodenum. Gastric acidity was calculated for 24 hours (1700-1659), night (2000-0759) and day-time (0800-1959).

RESULTS

Ulcer patients without gastric metaplasia showed a significantly higher gastric acidity (p < 0.001) than controls for every time interval considered, while the ulcer subgroup with gastric metaplasia was more acid than healthy subjects (p < 0.001) during the whole 24 hour period and the daytime. There was no difference between the two subgroups of duodenal ulcer patients with and without gastric metaplasia during the various time segments analysed.

CONCLUSION

The findings confirm that the circadian gastric acidity of duodenal ulcer patients is higher than that of controls. As there is no difference in gastric pH between duodenal ulcer patients with and without gastric metaplasia, gastric hyperacidity is not specific to patients with duodenal gastric metaplasia. It is probable that this histological change is a non-specific response to mucosal injury resulting from various factors and not exclusively to acid.

Helicobacter pylori: the missing link in perspective

Helicobacter pylori, an organism responsible for a common human infection, may act as a cofactor to produce gastrointestinal disease in a significant minority. The exact mechanisms of transmission are still unclear, but likely involve direct person-to-person spread and fecal-oral or waterborne/environmental transmission. Infection is a necessary condition for the development of duodenal ulcers and chronic nonspecific gastritis. It also likely contributes to the development of gastric ulcers, and the intestinal-type gastric carcinoma, but further studies are needed to confirm these hypotheses. Multiple effective treatment regimens currently exists. We recommend using bismuth, metronidazole, and tetracycline as the initial regimen of choice. Unfortunately, the relative importance of bacterial virulence factors is still unclear when compared with host susceptibility factors, and much knowledge needs to be gained about pathogenesis before vaccine development can proceed.

Gastric metaplasia and Helicobacter pylori infection

Duodenal and antral mucosal biopsy specimens were obtained from 139 patients with dyspeptic complaints to study the prevalence and extent of gastric metaplasia in the duodenal bulb in relation to Helicobacter pylori (H pylori) infection and duodenal ulcer disease. On logistic regression, the presence and extent of gastric metaplasia was not significantly associated with H pylori infection. The prevalence of gastric metaplasia, however, was found to be higher in patients with current or past evidence of duodenal ulcer disease in comparison with subjects with functional dyspepsia (p = 0.01). A follow up study on 22 patients before and at least one year after eradication of H pylori showed that the mean extent of gastric metaplasia did not change significantly after eradication and did not differ when compared with 21 patients with persisting infection. It is concluded that the unchanged gastric acid output after eradication of H pylori is a more important factor in the development of gastric metaplasia than the H pylori related inflammatory process.

The effects of sodium chloride, miso or ethanol on development of intestinal metaplasia after X-irradiation of the rat glandular stomach

The influence of sodium chloride (NaCl), miso (Japanese soybean paste) and ethanol on development of intestinal metaplasia was examined. Five-week-old male CD(SD): Crj rats were treated with two 10 Gy doses of X-rays to the gastric region at a 3-day interval (total 20 Gy). After irradiation, the rats received supplementation with NaCl (1% or 10% in diet), miso (10% in diet) or ethanol (10% in drinking water) for 12 months. The number of alkaline phosphatase-positive foci of intestinal metaplasia in rats given 1% NaCl diet (Group 3) after X-rays was significantly elevated as compared to that in rats given X-rays alone (Group 1) (P < 0.01) or X-rays with 10% NaCl (Group 2) (P < 0.01). In the pyloric gland mucosae, the total numbers of metaplastic foci in rats of Group 3 were much higher than in Group 2, or after miso diet (Group 4) or ethanol supplementation (Group 5) (P < 0.01), but no difference was found between Group 2, 4 or 5 and Group 1. Atypical hyperplasia only appeared at incidences of less than 6% in Groups 1-3 and no promoting effect on gastric tumorigenesis was evident in Group 2. The present results thus showed that the occurrence of intestinal metaplasia induced by X-irradiation can be significantly increased by administration of 1% NaCl and decreased by 10% NaCl and ethanol, but this is not associated with any influence on gastric neoplasia.

Effect of chewing Qat on mucosal histology and prevalence of Helicobacter pylori in the oesophagus, stomach and duodenum of Yemeni patients

This investigation was aimed at assessing whether the Yemeni habit of chewing Qat on a regular basis had a significant effect on the upper alimentary tract. Seventy patients with dyspepsia attending Al-Thawra Hospital in Taiz, Yemen Republic were examined by endoscopy. Biopsies were taken from the oesophagus, stomach and duodenum. The patients included 28 who gave a history of daily Qat intake, 21 with less frequent intake and 21 who took none. The only statistically significant finding associated with daily Qat intake was a higher prevalence of duodenal ulcer, particularly in females. However, a strong association was also found between heavy smoking and ulcer, with most ulcer patients who chewed Qat daily being heavy smokers. Chewing Qat was not associated with a higher prevalence of oesophageal dysplasia, making it unlikely to be the cause of the perceived high incidence of oesophageal carcinoma in Yemen. There was a high prevalence of gastric H. pylori colonization (93%) and columnar-lined lower end of oesophagus (18%), as well as low prevalence of intestinal metaplasia of stomach (4%); this was not, however, related to chewing Qat. Further epidemiological and histological studies are needed to assess the significance of these findings in relation to the incidence of oesophageal and gastric carcinoma in Yemen.

Gastric epithelium in the duodenum: its association with Helicobacter pylori and inflammation

Duodenal biopsy specimens from 471 adults and 47 children were examined to determine the prevalence and distribution of gastric epithelium in the duodenal bulb in relation to age, gender, gastroduodenal inflammation, smoking, alcohol and consumption of nonsteroidal anti-inflammatory drugs (NSAID). Gastric metaplasia was present in the anterior wall duodenal biopsy specimen in 31%, was significantly less common in patients under 17 than in adults, and was more common in males than females. In sixty two adults who underwent multiple radial duodenal biopsy gastric metaplasia was randomly distributed around the duodenal circumference; sixty three per cent of the patients with gastric metaplasia found on multiple biopsy were detected by just the anterior biopsy. Gastric metaplasia was not obviously associated with alcohol, cigarette, or NSAID consumption. While the presence of gastric metaplasia was associated with adulthood, male sex, and low fasting gastric juice pH, its extent was associated with active duodenitis and Helicobacter-associated gastritis. On logistic regression, gastric metaplasia in the duodenum and gastric Helicobacter pylori were independent predictors of active duodenitis, but were not significantly associated with inactive duodenal inflammation. H pylori was observed in duodenal biopsy specimens from 32 patients, all with active duodenitis; bacteria were present only on foci of gastric metaplasia, and were more likely to be seen when the metaplasia was extensive. It is proposed that inflammatory injury to the duodenal mucosa by H pylori may stimulate the development of further gastric metaplasia, and that the area of duodenum susceptible to colonisation with H pylori may therefore increase progressively until mucosal integrity is compromised and ulceration supervenes.

Impact of diet and smoking on risk of developing intestinal metaplasia of the stomach

A cohort of Hawaii Japanese men was assembled for epidemiologic studies of heart disease and cancer. Diet and tobacco consumption data were obtained from 1965 to 1968 and from 1971 to 1975. Biopsies from sites at maximal, intermediate, and minimal risk of intestinal metaplasia were performed on 350 men. Metaplasia was found in 234 men. Gastric cancer was found in 9/234 with metaplasia (3.8%) and 1/116 men without metaplasia (0.89%). Nitrite-rich salty foods (e.g., cured meats) were directly related to metaplasia at both examinations. Vitamin C intake did not appear to have prevented the development of intestinal metaplasia. Smoking was directly related to the presence of metaplasia, but the association was weaker than was observed for cured meats. The strong association between nitrite-rich salty foods and metaplasia appears to be uniform from one study to another, as is the lack of a consistent relation between metaplasia and either smoking or vitamin C consumption. Heavy smokers were more likely to have metaplasia than were nonsmokers, but these associations were weaker than were those with cured meats.

The clinical relevance of endoscopic and histologic inflammation of gastroduodenal mucosa in dyspepsia of unknown origin

Two hundred and ten patients were defined as having dyspepsia of unknown origin. At endoscopy 11% had body gastritis, 46% antral gastritis, and 19% bulbitis (two thirds combined with antral gastritis). Histologically, 22% had chronic corpus gastritis (79% superficial, 21% atrophic), which was combined with chronic antral gastritis in 84%, 33% had chronic antral gastritis (82% superficial, 18% atrophic); and 14% had duodenitis, which was combined with antral gastritis in 65%. Polymorphonuclear leukocytes were found in specimens from the body mucosa in 6%, from the antral mucosa in 13%, and from the duodenal cap in 4%. The endoscopic findings correlated significantly with the histologic findings in the duodenal bulb (kappa = 0.33) but not in the stomach. The frequency of endoscopic antral gastritis and the frequency of histologic chronic body and antral gastritis increased with age. Endoscopic bulbitis and histologic duodenitis and gastric metaplasia were commoner in men than in women. Peak acid output was higher in patients with than in those without endoscopic bulbitis and higher in smokers than in non-smokers when the significant sex differences in peak acid output were taken into account. Gastric metaplasia of the bulb was predominantly correlated to higher peak acid output and to some extent also to sex and smoking. Episodic pain was correlated to histologic duodenitis. Other dyspeptic symptoms and the intragastric bile acid concentration were not associated with any endoscopic or histologic findings. Of the 210 patients, 172 were reexamined after a double-blind 6-week treatment period with cimetidine, antacid, or placebo. The symptomatic outcome of these treatments was not associated with any significant change in endoscopic or histologic findings.

Gastric metaplasia and Campylobacter pylori infection of duodenum in patients with chronic renal failure

Duodenal biopsy specimens from 80 patients with chronic renal failure, who were undergoing haemodialysis, were examined by light microscopy for evidence of inflammation, gastric metaplasia, and Campylobacter pylori infection. Chronic duodenitis was present in 47 (59%) of patients, of whom only seven (9%) showed evidence of active inflammation. Gastric metaplasia was present in 50 (62.5%) of patients, yet Campylobacter pylori was identified in only two patients (2.5%). It is suggested that the duodenal environment of patients with chronic renal failure remains hostile to the growth of these organisms in spite of the presence of gastric metaplasia.

Ferritin and lysozyme distribution in normal and abnormal duodenal mucosae

The distribution of ferritin and lysozyme in 19 normal and abnormal duodenal biopsies was studied by an immunoperoxidase technique. The abnormal biopsies included cases of chronic duodenitis with gastric metaplasia, gastric heterotopia, villous atrophy, and a case of hemochromatosis. Ferritin is demonstrated in duodenal absorptive cells, with the staining being most intense in the hemochromatosis case. It was absent in duodenal cells showing gastric metaplasia and in the surface epithelial cells of most biopsies with villous atrophy and gastric heterotopia. Lysozyme-positive mononuclear inflammatory cells were markedly increased in all abnormal biopsies. Not all lysozyme-positive cells were ferritin positive. The latter were especially abundant in areas with gastric metaplasia. It is suggested that this abundance may be related to passive diffusion of intestinal contents, particularly iron, through the metaplastic areas, and consequently there may be a relationship between the presence of duodenal gastric metaplasia and uncontrolled iron absorption.