Iron-deficiency anemia and Helicobacter pylori infection: a review of the evidence.

Background and Aims:  We carried out a systematic literature review and meta-analysis to evaluate the existing evidence on the association between Helicobacter pylori infection and iron stores.



Methods:  Twelve case reports and case series, 19 observational epidemiologic studies and six intervention trials were included in the review.



Results:  Although only few studies controlled for multiple potential confounders, most studies reported a positive association, linking between H. pylori and decreased body iron stores in symptomatic and asymptomatic H. pylori-infected subjects. H. pylori infection may be regarded as a risk factor for reduction in body iron stores and also for iron deficiency or iron deficiency anemia, especially in high-risk groups. The results of the meta-analysis of thoroughly designed and analyzed studies revealed an increased risk for iron deficiency anemia; pooled odds ratio (OR) 2.8 (95% confidence interval (CI) 1.9, 4.2) and also for iron deficiency; pooled OR 1.38 (95%CI 1.16–1.65) among H. pylori-infected subjects. The biologic mechanism by which H. pylori induces the alteration in the iron stores is not fully understood, but it seems to involve several pathways, including gastrointestinal blood loss, decrease in the absorption of dietary iron, and enhanced uptake of the iron by the bacterium.



Conclusions: H. pylori is associated with reduced iron stores. Future research is needed to determine whether this relationship is a causal association and to better understand its biologic mechanism. The impact of anti-H. pylori therapy on improvement of iron stores needs to be further evaluated in large and well-controlled trials.

Helicobacter pylori Infection and Iron Stores: A Systematic Review and Meta‐analysis

AIM: To perform a meta-analysis of observational studies and randomized controlled trials (RCTs) on the association between Helicobacter pylori (H. pylori) and iron deficiency anemia (IDA).

METHODS: A defined search strategy was used to search Medline, Embase, the Cochrane Library, Clinical Trials, Cochrane Central Register of Controlled Trials, Premedline and Healthstar. Odds ratio (OR) was used to evaluate observational epidemiology studies, and weighted mean difference (WMD) was used to demonstrate the difference between control and intervention groups.

RESULTS: Fifteen observational studies and 5 RCTs were identified and used for calculation. The pooled OR for observational studies was 2.22 (95% CI: 1.52-3.24, P < 0.0001). The WMD for hemoglobin (HB) was 4.06 g/L (95% CI: -2.57-10.69, P = 0.01), and the WMD for serum ferritin (SF) was 9.47 μg/L (95% CI: -0.50-19.43, P < 0.0001). Results were heterogeneous for all comparisons.

CONCLUSION: This meta-analysis on observational studies suggests an association between H. pylori and IDA. In RCTs, eradication of H. pylori can improve HB and SF levels but not significantly.

Does Helicobacter pylori infection play a role in iron deficiency anemia? A meta-analysis

As an update to previously published recommendations for the management of Helicobacter pylori infection, an evidence-based appraisal of 14 topics was undertaken in a consensus conference sponsored by the Canadian Helicobacter Study Group. The goal was to update guidelines based on the best available evidence using an established and uniform methodology to address and formulate recommendations for each topic. The degree of consensus for each recommendation is also presented. The clinical issues addressed and recommendations made were: population-based screening for H. pylori in asymptomatic children to prevent gastric cancer is not warranted; testing for H. pylori in children should be considered if there is a family history of gastric cancer; the goal of diagnostic interventions should be to determine the cause of presenting gastrointestinal symptoms and not the presence of H. pylori infection; recurrent abdominal pain of childhood is not an indication to test for H. pylori infection; H. pylori testing is not required in patients with newly diagnosed gastroesophageal reflux disease; H. pylori testing may be considered before the use of long-term proton pump inhibitor therapy; testing for H. pylori infection should be considered in children with refractory iron deficiency anemia when no other cause has been found; when investigation of pediatric patients with persistent or severe upper abdominal symptoms is indicated, upper endoscopy with biopsy is the investigation of choice; the 13C-urea breath test is currently the best noninvasive diagnostic test for H. pylori infection in children; there is currently insufficient evidence to recommend stool antigen tests as acceptable diagnostic tools for H. pylori infection; serological antibody tests are not recommended as diagnostic tools for H. pylori infection in children; first-line therapy for H. pylori infection in children is a twice-daily, triple-drug regimen comprised of a proton pump inhibitor plus two antibiotics (clarithromycin plus amoxicillin or metronidazole); the optimal treatment period for H. pylori infection in children is 14 days; and H. pylori culture and antibiotic sensitivity testing should be made available to monitor population antibiotic resistance and manage treatment failures.

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Canadian Helicobacter Study Group Consensus Conference: Update on the approach to Helicobacter pylori infection in children and adolescents--an evidence-based evaluation.

Background: Seroepidemiological and clinical studies suggest that Helicobacter pylori may cause iron deficiency anaemia (IDA) in the absence of peptic lesions by undefined mechanisms, which still remain to be fully elucidated. Gastric acidity and ascorbic acid (AA) promote iron absorption. AA is lowered in the presence of H pylori infection. H pylori can cause atrophic body gastritis with achlorhydria, decreased iron absorption, and consequent IDA. Whether alterations in intragastric acidity and AA concentrations play a role in IDA developing in patients with H pylori gastritis remains to be determined . Aim: To evaluate gastric juice pH and gastric juice and plasma AA in patients with H pylori infection and unexplained IDA, compared with controls with IDA and a healthy stomach or with controls with H pylori infection and no IDA. Results: Patients with IDA and H pylori gastritis were characterised by concomitant increased intragastric pH (median value 7) and decreased intragastric AA (median value 4.4 μg/ml) compared with controls with a healthy stomach (median pH 2; median intragastric AA 17.5 μg/ml) and with H pylori positive controls without IDA (median pH 2.1; median intragastric AA 7.06 μg/ml). Intragastric AA was inversely related to pH ( r =−0.40, p=0.0059) and corporal degree of gastritis ( r =−0.53, p=0.0039). Plasma AA concentrations were lower in all infected groups than in healthy controls. Conclusions: Patients with unexplained IDA and H pylori gastritis present concomitant changes in intragastric pH and AA that may justify impaired alimentary iron absorption and consequent IDA.

https://gut.bmj.com/content/gutjnl/52/4/496.full.pdf

Concomitant alterations in intragastric pH and ascorbic acid concentration in patients with Helicobacter pylori gastritis and associated iron deficiency anaemia

Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes.

Background Poor living conditions, such as overcrowding and bed-sharing, are reported to be significant risk factors for Helicobacter pylori infection throughout childhood. We investigated the prevalence of H. pylori infection in Korean athletes who are obliged to live together in training camps for more than 6 months in a year.



Methods Blood sampling and surveying through questionnaire were performed on 440 students from a regular high school (228 boys and 212 girls) and 220 athletes (148 boys and 72 girls) of a physical education high school. We measured serum immunoglobulin G antibody (IgG Ab) to H. pylori in order to compare the prevalence of H. pylori infection between normal adolescents and athletes. In addition, we conducted a nutritional analysis and questionnaire survey for socioeconomic status in order to compare other risk factors that might influence H. pylori infection between groups.



Results The prevalence of H. pylori infection in athletes (43.2%) was higher than that in the controls (22.7%). No significant differences in the nutritional factors or socioeconomic status, such as Hollingshead index, type of house, number of siblings, and crowding index, were found between the groups. Multivariate analysis showed that crowding and the difference in school type were the significant predictors of H. pylori seropositivity after controlling for dietary and socioeconomic factors.



Conclusion The seroprevalence of H. pylori infection was higher in adolescent athletes than in age- and sex-matched regular students. Further prospective study is needed to confirm the observation.

Tae Sook Hwang

Papers

Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes.

Higher seroprevalence of Helicobacter pylori infection in Korean adolescent athletes compared to age- and sex-matched non-athletes.