Systematic review with meta-analysis: the worldwide prevalence of Helicobacter pylori infection.

BACKGROUND: The epidemiology of Helicobacter pylori infection is poorly understood. AIM: To establish the reported regional and national prevalence of H. pylori infection, stratified by age and gender. METHODS: All relevant English publications from 2000 to 2017 cited by PubMed and Scopus were retrieved using comprehensive combinations of keywords. The overall prevalence of H. pylori was estimated using both random effect and fixed effect meta-analyses, and presented as prevalence rate (% and 95% CI). The analyses were extended by separation into gender and age groups. RESULTS: A total of 14 056 records were obtained initially. After applying exclusion criteria in several steps, 183 studies were selected. Analysis of 410 879 participants from 73 countries in six continents revealed an overall prevalence of 44.3% (95% CI: 40.9-47.7) worldwide. This rate ranged from 50.8% (95% CI: 46.8-54.7) in developing countries compared with 34.7% (95% CI: 30.2-39.3) in developed countries. The global H. pylori infection rate was 42.7% (95% CI: 39-46.5) in females compared to 46.3% (95% CI: 42.1-50.5) in males. The prevalence in adults (≥18 years) was significantly higher than in children (48.6% [95% CI: 43.8-53.5] vs 32.6% [95% CI: 28.4-36.8], respectively). There was a statistically nonsignificant decrease in the prevalence in 2009-2016 compared with the 2000-2009 period. CONCLUSIONS: The observed differences between countries appear to be due to economic and social conditions. H. pylori infection can be a benchmark for the socioeconomic and health status of a country. Further studies are suggested to investigate the natural history of the acquisition of H. pylori infection from childhood into adult life.

Kinetics of transient hiatus hernia during transient lower esophageal sphincter relaxations and swallows in healthy subjects.

BACKGROUND: Proximal displacement of the gastro-esophageal junction (GEJ) is present in hiatus hernia but also occurs transiently during transient lower esophageal sphincter relaxations (TLESRs) and swallows. Using a novel magnetic-based technique we have performed detailed examination of the GEJ movement during TLESRs and swallows in healthy subjects. METHODS: In 12 subjects, a magnet was endoscopically clipped to the GEJ and combined assembly of Hall-Effect locator probe and 36 channel high-resolution manometer passed nasally. After a test meal the subjects were studied for 90 min. KEY RESULTS: The median amplitude of proximal movement of GEJ during TLESRs was 4.3 cm (1.6-8.8 cm) and this was substantially greater than during swallowing at 1.2 cm (0.4-2.7 cm), P = 0.002. With both TLESRs and swallows proximal GEJ movement coincided with lower esophageal sphincter (LES) relaxation and return to its original position occurred 4 s after return of LES tone. Kinetic modeling of the movement of the GEJ during TLESRs indicated two return phases with the initial return phase having the greater velocity (0.9 cm s(-1) ) and being strongly correlated with amplitude of proximal movement (r = 0.8, P < 0.001). CONCLUSIONS & INFERENCES: The marked proximal GEJ migration during TLESRs represents very severe herniation of the GEJ. The rapid initial return of the GEJ following TLESRs when the crural diaphragm is relaxed and its correlation with amplitude suggest it is due to elastic recoil of the phreno-esophageal ligament. The marked stretching of the phreno-esophageal ligament during TLESRs may contribute to its weakening and development of established hiatus hernia.

High-resolution esophageal manometry: addressing thermal drift of the manoscan system.

BACKGROUND: The high resolution esophageal manometry system manufactured by Sierra Scientific Instruments is widely used. The technology is liable to 'thermal drift', a change in measured pressure due to change in temperature. This study aims to characterize 'thermal drift' and minimize its impact. METHODS: Response of the system to immediate temperature change (20 °C to 37 °C) was tested. Accuracy of pressure measurement over two hours at 37 °C was examined. Six repetitions were performed and median pressure change calculated for each sensor. Sensors were compared using Kruskal-Wallis test. Current correction processes were tested. KEY RESULTS: There was a biphasic response of the system to body temperature: an immediate change in recorded pressure, 'thermal effect' and an ongoing pressure change with time, 'baseline drift'. Median thermal effect for all 36 sensors was 7 mmHg (IQR 3.8 mmHg). Median baseline drift was 11.1 mmHg (IQR 9.9 mmHg). Baseline drift varied between sensors but for a given sensor was linear. Interpolated thermal compensation, recommended for prolonged studies, corrects data assuming a linear drift of pressures. When pressures were corrected in this way, baseline pressure was almost restored to zero (Median 0.3 mmHg, IQR 0.3). The standard thermal compensation process did not address the error associated with baseline drift. CONCLUSIONS & INFERENCES: Thermal effect is well compensated in the current operation of the system but baseline drift is not well recognized or addressed. Incorporation of a linear correction into current software would improve accuracy without impact on ease of use.

Male predominance of upper gastrointestinal adenocarcinoma cannot be explained by differences in tobacco smoking in men versus women.

BACKGROUND: Adenocarcinomas of the upper gastrointestinal tract (UGI) show remarkable male predominance. As smoking is a well-established risk factor, we investigated the role of tobacco smoking in the male predominance of UGI adenocarcinomas in the United States NIH-AARP Diet and Health Study. METHOD: A questionnaire was completed by 281,422 men and 186,133 women in 1995-1996 who were followed until 31st December 2003. Incident UGI adenocarcinomas were identified by linkage to state cancer registries. We present age-standardised cancer incidence rates per 100,000-person years and male/female ratios (M/F) calculated from age-adjusted Cox proportional hazards models, both with 95% confidence intervals (CI). RESULTS: After 2013,142-person years follow-up, 338 adenocarcinomas of the oesophagus, 261 of gastric cardia and 222 of gastric non-cardia occurred in men. In women, 23 tumours of oesophagus, 36 of gastric cardia and 88 of gastric non-cardia occurred in 1351,958-person years follow-up. The age-standardised incidence rate of all adenocarcinoma sites was 40.5 (37.8-43.3) and 11.0 (9.2-12.8) in men and women, respectively. Among smokers, the M/F of all UGI adenocarcinomas was 3.4 (2.7-4.1), with a M/F of 7.3 (4.6-11.7) for tumours in oesophagus, 3.7 (2.5-5.4) for gastric cardia and 1.7 (1.2-2.3) for gastric non-cardia. In non-smokers, M/F ratios were 14.2 (5.1-39.5) for oesophagus, 6.1 (2.6-14.7) for gastric cardia and 1.3 (0.8-2.0) for gastric non-cardia. The overall M/F ratio was 3.0 (2.2-4.3). CONCLUSION: The male predominance was similar in smokers and non-smokers for these cancer sites. These results suggest that the male predominance of upper GI adenocarcinomas cannot be explained by differences in smoking histories.

Oesophageal and gastric intestinal-type adenocarcinomas show the same male predominance due to a 17 year delayed development in females.

BACKGROUND AND AIMS: Upper gastrointestinal adenocarcinomas show an unexplained male predominance that is more apparent in oesophagus than stomach and in intestinal than diffuse histological subtype. We have conducted a population-based study to determine whether the gender phenomenon is primarily related to the anatomical site or the histological subtype. METHOD AND MATERIALS: Of 3270 gastric and oesophageal cancers recorded in the West of Scotland Cancer Registry, 1998-2002, 812 were randomly selected for detailed analysis. The Lauren histological subtype of adenocarcinoma was determined by reviewing 1204 original reports and 3241 biopsies. RESULTS: Analysis included 405 non-cardia cancers, 173 cardia cancers and 209 oesophageal adenocarcinomas. Crude incidence rate of intestinal subtype was higher in males (23.86/100,000 person-years) versus females (9.00/100,000 person-years), giving a male/female (M/F) ratio of 2.65 whereas diffuse subtype was similar for both genders (5.58 vs 5.20/100,000 person-years) yielding M/F of 1.07. The M/F ratios for oesophageal, cardia and non-cardia gastric cancer were 3.5, 2.0 and 1.6, respectively. Multiple logistic regression indicated that the odds of male gender was related to the histological subtype rather than anatomical location (odds ratio 2.6, 95% confidence interval 1.78 to 3.9). Curve fitting of the age-specific incidence of intestinal subtype indicated that similar functions describe the rise in incidence with age in males and in females. However, the age-specific incidence of female intestinal subtype was delayed by 17.3 years. The M/F ratio of intestinal subtype was 3.41 at age <50 years, peaked at 7.86 at age 50-59 years and then showed a progressive decrease after 50-60 years of age. CONCLUSION: Male predominance of upper gastrointestinal adenocarcinoma is related to the intestinal histological subtype rather than tumour location and is due to marked delayed development of this subtype in females prior to 50-60 years of age.

Combination of gastric atrophy, reflux symptoms and histological subtype indicates two distinct aetiologies of gastric cardia cancer.

INTRODUCTION: Atrophic gastritis is a risk factor for non-cardia gastric cancer, and gastro-oesophageal reflux disease (GORD) for oesophageal adenocarcinoma. The role of atrophic gastritis and GORD in the aetiology of adenocarcinoma of the cardia remains unclear. We have investigated the association between adenocarcinoma of the different regions of the upper gastrointestinal tract and atrophic gastritis and GORD symptoms. METHODS: 138 patients with upper GI adenocarcinoma and age- and sex-matched controls were studied. Serum pepsinogen I/II was used as a marker of atrophic gastritis and categorised to five quintiles. History of GORD symptoms, smoking and H pylori infection were incorporated in logistic regression analysis. Lauren classification of gastric cancer was used to subtype gastric and oesophageal adenocarcinoma. RESULTS: Non-cardia cancer was associated with atrophic gastritis but not with GORD symptoms; 55% of these cancers were intestinal subtype. Oesophageal adenocarcinoma was associated with GORD symptoms, but not with atrophic gastritis; 84% were intestinal subtype. Cardia cancer was positively associated with both severe gastric atrophy [OR, 95% CI: 3.92 (1.77 to 8.67)] and with frequent GORD symptoms [OR, 95% CI: 10.08 (2.29 to 44.36)] although the latter was only apparent in the non-atrophic subgroup and in the intestinal subtype. The association of cardia cancer with atrophy was stronger for the diffuse versus intestinal subtype and this was the converse of the association observed with non-cardia cancer. CONCLUSION: These findings indicate two distinct aetiologies of cardia cancer, one arising from severe atrophic gastritis and being of intestinal or diffuse subtype similar to non-cardia cancer, and one related to GORD and intestinal in subtype, similar to oesophageal adenocarcinoma. Gastric atrophy, GORD symptoms and histological subtype may distinguish between gastric versus oesophageal origin of cardia cancer.

Antimicrobial effectiveness of furazolidone against metronidazole-resistant strains of Helicobacter pylori.

The occurrence of strains resistant to metronidazole is causing failure of the 4-drug regimen for eradication of Helicobacter pylori in the Islamic Republic of Iran. This study compared the in vitro efficacy of furazolidone with metronidazole, clarithromycin, amoxicillin and tetracycline in 70 H. pylori isolates from dyspeptic patients. Of the isolates, 33% were resistant to metronidazole but all were susceptible to furazolidone. Furazolidone could be considered as an appropriate substitute for metronidazole for H. pylori infections.

Gastric histology, serological markers and age as predictors of gastric acid secretion in patients infected with Helicobacter pylori.

BACKGROUND: Acid secretion is intimately associated with most upper gastrointestinal diseases. Helicobacter pylori infection is a major environmental factor modifying acid secretion. AIM: To study the association between the pattern of H pylori gastritis and gastric secretory function in a large number of subjects without specific upper gastrointestinal disease. METHODS AND MATERIALS: Maximal acid output (MAO) was measured in 255 patients with dyspepsia showing normal endoscopy. Activity and severity of gastritis, atrophy and H pylori infection were assessed in body and antral biopsies. The correlations of histological parameters as well as age, sex, height, weight, smoking, serum gastrin, pepsinogen I and II, and their ratio with MAO were determined. Multiple linear regression was used to show the best possible predictors of MAO. RESULTS: Negative relationships: Body atrophy and body-combined (active and chronic) inflammatory scores showed a potent inverse correlation with MAO (correlation coefficients (CC) 0.59 and 0.50, respectively). Body:antral chronic gastritis ratio and body:antral combined inflammation ratio (both with CC = 0.49) and age (CC = 0.44) were also inversely correlated with MAO. Intestinal metaplasia at both antral and body sites had negative relationships with acid output with CC = 0.23 and 0.20, respectively. Positive relationships: Serum pepsinogen I, body H pylori density:combined inflammation ratio and pepsinogen I:II ratio with CC of 0.38, 0.38 and 0.30, respectively, correlated with MAO. The H pylori density: combined inflammation of both antrum and body positively correlated with MAO (CC = 0.29 and 0.38, respectively). Male sex and patient height also positively correlated with acid output. Modelling showed that body combined inflammatory score, body atrophy, age and serum pepsinogen I are independent predictors of acid output (R(2) = 0.62). CONCLUSION: Combination of body gastritis, body atrophy, age and serum pepsinogen I can be used as predictors of acid-secretory state in populations infected with H pylori.

Lower oesophageal sphincter pressure and timed barium oesophagogram: two objective parameters in the non-invasive assessment of primary achalasia.

BACKGROUND: The non-invasive assessment of primary achalasia is not precise. AIM: To compare investigations before and 1 month after balloon dilation in achalasia. METHODS: Fifty-two patients with primary achalasia were enrolled. Subjective and objective variables of oesophageal functions were analysed before and 1 month after balloon dilation. RESULTS: The mean predilation symptom score, lower oesophageal sphincter pressure, height and volume of barium at 5 min were 7.7 +/- 2.6, 62.0 +/- 25.1 mmHg, 9.2 +/- 6.1 cm and 53.2 +/- 49.8 mL respectively; the mean postdilation values were 3.0 +/- 3.0, 34.1 +/- 12.5 mmHg, 7.9 +/- 5.1 cm and 28.0 +/- 30.1 mL respectively. The before dilation volume of barium at 5 min correlates significantly with lower oesophageal sphincter pressure (P < 0.01). The mean symptom scores, lower oesophageal sphincter pressure and volume of barium at 5 min dropped significantly after intervention (P < 0.01), but the reduction in barium height at 5 min was not significant. The percentage changes in volume at 5 min significantly predicted the percentage changes in lower oesophageal sphincter pressure (P < 0.01). CONCLUSIONS: The volume of barium retention at 5 min can predict the lower oesophageal sphincter pressure before and after balloon dilation in primary achalasia. This could be used as a non-invasive objective tool for initial and post-dilation assessment.

High incidence of adenocarcinoma arising from the right side of the gastric cardia in NW Iran.

BACKGROUND: In the West, the subsite incidence of gastric cancer has changed in recent decades, with cancer of the cardia increasing in incidence and that of the more distal stomach decreasing. NW Iran has a very high incidence of upper gastrointestinal cancer and we have examined the anatomical site specific incidence in this geographical region. METHOD AND MATERIALS: Of 33 718 patients who visited our clinic from March 2000 to Jan 2003, 3119 (9.3%) with persistent upper gastrointestinal symptoms underwent upper gastrointestinal fibreoptic endoscopy. Exact tumour site, subsite, and axial view were determined. Demographic data including age, sex, and place of residence were assessed. Using matched data from the cancer registry and endoscopic survey, age standardised rates (ASR) for all subsites were calculated. RESULTS: Upper gastrointestinal cancer was diagnosed histologically in 499 patients (16.0%). The most frequent site was the gastric cardia (126 (25.3%)) followed by the oesophageal body (90 (18.0%)), antrum (82 (16.4%)), corpus (74 (14.8%)), distal oesophagus (57 (11.4%)), gastro-oesophageal junction (47 (9.4%)), and proximal oesophagus (22 (4.4%)). From axial views of the cardia, 51.4% and 6.8% of tumours were found to originate from the lesser and greater curve, respectively. ASR for gastric cancer were 51.2 in males and 15.4 in females. Cardia cancer with ASR of 26.4 in males and 8.6 in females was the major component of gastric cancer. CONCLUSION: NW Iran is a geographical region with a very high incidence of cardia cancer and with the great majority originating from the right side of the cardia. This suggests a locally acting luminal carcinogen. Studying the aetiology of this cancer in NW Iran is likely to increase our understanding of the rising incidence of this cancer throughout the Western world.

Prevalence of gastric precancerous lesions in Ardabil, a high incidence province for gastric adenocarcinoma in the northwest of Iran.

BACKGROUND/AIMS: Ardabil Province, in northwestern Iran, has the highest rate of gastric (predominantly cardia) adenocarcinoma in Iran. This study aimed to investigate the feasibility of endoscopic screening and to look for associated Helicobacter pylori infection and gastric precancerous lesions. METHODS: One thousand one hundred and five adult volunteers, residents of Ardabil and Meshkinshahr, districts, 40 years old and above were selected and invited by a simple random household canvass in rural and urban locations. Informed consents were obtained and upper gastrointestinal video endoscopy was performed to biopsy all visible lesions and standard sites in the antrum, corpus, and cardia. RESULTS: One thousand and eleven of the invited individuals agreed to participate, including 494 men and 517 women, with a mean (SD) age of 53.32 (10.39) years. Endoscopy was well tolerated by all subjects; 96.7% of antral and 80.7% of cardia mucosal biopsies were satisfactory. The urease test or histology for H pylori was positive in at least 89.2% of subjects. Histological evidence of mucosal atrophy was seen in 39.3% of antral and 21.9% of cardia samples. Chronic gastritis with or without activity, reactive atypia of glandular epithelium, intestinal metaplasia, dysplasia, and cancer were found in 95.1%, 38.0%, 8.7%, 0.2%, and 0.3% of antral and 85.3%, 22.9%, 3.8%, 0.3%, and 0.1% of cardiac biopsies, respectively. CONCLUSION: Endoscopic screening for upper gastrointestinal diseases was feasible and well tolerated in Ardabil, Iran. Most subjects showed H pylori infection. Atrophic gastritis, reactive atypia, and intestinal metaplasia were common in antrum, corpus, and cardia subsites.

Effect of Helicobacter pylori eradication or of ranitidine plus metoclopramide on Helicobacter pylori-positive functional dyspepsia. A randomized, controlled follow-up study.

BACKGROUND: A definitive treatment for functional dyspepsia (FD), and the role of Helicobacter pylori eradication on the course of this disease are controversial. AIM: To investigate the effect of a combination of acid-suppressing and prokinetic drugs or eradication therapy on the course of H. pylori-positive FD. METHOD: A total of 157 patients with endoscopically-proven H. pylori-positive FD and no response to 4 weeks of antacid therapy were randomly divided into 2 groups. 84 were placed on bismuth subnitrate plus metronidazole and amoxicillin (group A) and 73 received ranitidine and metoclopramide for 4 weeks (group B). The severity of symptoms (7 items) were assessed on a 6-point categorical scale. Group B patients who failed to respond to their medication underwent eradication therapy after 3 months. All patients were followed and assessed for 9 months after the end of therapy by the same clinicians who initiated the therapy. RESULTS: At the end of the medication period, symptom's score decreased significantly, and to the same extent. At 3-month follow-up moderate or complete response was achieved in 27.4% (group A) and 19.2% (group B) by intention-to-treat analysis. 34 patients of group B, not responding to treatment, underwent eradication therapy and followed as group A. Eradication of H. pylori was successful in 60 of 110 controlled patients (54%). After 9-month follow-up, complete or moderate response was observed in only 30% of 60 patients in whom H. pylori had been eradicated (intention-to-treat analysis), compared to 38% in 50 noneradicated cases (p > 0.05, 95% CI: 19-43 vs. 24-52). CONCLUSION: Eradication therapy with bismuth compound is effective as ranitidine plus metoclopramide in a subgroup of patients with FD not responding to antacid therapy. There is no difference in improvement between patients cured or not cured from H. pylori infection. This suggests that bismuth compounds were effective in FD when used in the eradication regimen. Combination therapy with acid-suppressing drugs plus prokinetic and bismuth seems to hold promise for FD.

Endoscopic esophageal cancer survey in the western part of the Caspian Littoral.

After a hiatus of 30 years an attempt is now being made to re-assess the previously reported very high esophageal cancer incidence rates in the Caspian Littoral. The extraordinarily high incidence rates found in the eastern side of the Littoral, were re-confirmed five years ago for the Turkoman region, using esophageal balloon cytology supplemented by esophagoscopy of suspected cases. The focus this time was on the Ardabil province in the western side of the Caspian Littoral, where the rates reported 30 years ago were moderately high. A pilot chromoendoscopic screening program was scheduled for 650 asymptomatic adults from a randomly selected part of the city of Ardabil and adjoining villages, to evaluate the overall patterns of esophageal disease and to establish the utility of endoscopy as an esophageal cancer screening tool. 504 healthy volunteers, giving a compliance rate of 77.5%, submitted to esophagogastroscopy without any mishaps. Contrary to expectation, no dysplasia or esophageal cancer was found in 914 satisfactory biopsy specimens. Total absence of esophageal cancer or precursor dysplastic changes in the surveyed population in the western part of the Caspian Littoral was at variance with the cancer registry findings of three decades ago for the western part of the Littoral. A plausible explanation could be the improved socio-economic conditions and life style changes which have taken place in the recent past all along the Caspian Littoral, except in the Turkoman Plain.