Role of Helicobacter pylori infection in iron deficiency during pregnancy

Temporal trends of hemoglobin among pregnant women: The Mutaba'ah study

BACKGROUND

Low hemoglobin (Hb) level is a leading cause of many adverse pregnancy outcomes. Patterns of changes in Hb levels during pregnancy are not well understood.

AIM

This study estimated Hb levels, described its changing patterns across gestational trimesters, and identified factors associated with these changes among pregnant women.

MATERIALS AND METHODS

Data from the ongoing maternal and child health cohort study-The Mutaba'ah Study, was used (N = 1,120). KML machine learning algorithm was applied to identify three distinct cluster trajectories of Hb levels between the first and the third trimesters. Descriptive statistics were used to profile the study participants. Multinomial multivariable logistic regression was employed to identify factors associated with change patterns in Hb levels.

RESULTS

The three identified clusters-A, B and C-had, respectively, median Hb levels (g/L) of 123, 118, and 104 in the first trimester and 119, 100, and 108 in the third trimester. Cluster 'A' maintained average normal Hb levels in both trimesters. Cluster 'B', on average, experienced a decrease in Hb levels below the normal range during the third trimester. Cluster 'C' showed increased Hb levels in the third trimester but remained, on average, below the normal range in both trimesters. Pregnant women with higher gravida, diabetes mellitus (type 1 or 2), nulliparity or lower level of education were more likely to be in cluster 'B' than the normal cluster 'A'. Pregnant women who reported using iron supplements before pregnancy or those with low levels of education. were more likely to be in cluster 'C' than the normal cluster 'A'.

CONCLUSION

The majority of pregnant women experienced low Hb levels during pregnancy. Changes in Hb levels during pregnancy were associated with parity, gravida, use of iron before pregnancy, and the presence of diabetes mellitus (type 1 or 2).

The impact of response to iron therapy on maternal and neonatal outcomes among pregnant women with anemia

BACKGROUND

Anemia during pregnancy is associated with increased risks of preterm birth, preeclampsia, cesarean delivery, and maternal morbidity. The most prevalent modifiable cause of pregnancy-associated anemia is iron deficiency. However, it is still unclear whether iron therapy can reduce the risks of adverse outcomes in women with anemia.

OBJECTIVE

This study aimed to determine whether response to iron therapy among women with anemia is associated with a change in odds of adverse maternal and neonatal outcomes.

STUDY DESIGN

This was a population-based cohort study (2011-2019) using an institutional database composed of obstetrical patients from 2 delivery hospitals. Patients with adequate prenatal care were classified as being anemic or nonanemic (reference). Patients with anemia were further stratified by success or failure of treatment with oral iron therapy using the American College of Obstetricians and Gynecologists criteria for anemia at the time of admission for delivery: successfully treated (Hgb≥11 g/dL) or unsuccessfully treated ("refractory;" Hgb<11 g/dL). All categories of women with anemia categories were compared with the reference group of women without anemia using chi-square and logistic regression analyses. The primary outcomes were preterm birth and preeclampsia.

RESULTS

Among the 20,690 women observed, 7416 (35.8%) were anemic. Among women with anemia, 1319 (17.8%) were refractory to iron therapy, 2695 (36.3%) had a successful response to therapy, and 3402 (45.9%) were untreated. Successfully treated patients with anemia had a significant reduction in the odds of preterm birth (5.1% vs 8.3%; adjusted odds ratio, 0.59; 95% confidence interval, 0.47-0.72) and preeclampsia (5.9% vs 8.3%; adjusted odds ratio, 0.75; 95% confidence interval, 0.61-0.91). Refractory and untreated patients had significantly increased odds of preterm birth (adjusted odds ratio, 1.44 [95% confidence interval, 1.16-1.76] and 1.45 [95% confidence interval, 1.26-1.67], respectively) and preeclampsia (adjusted odds ratio, 1.54 [95% confidence interval, 1.24-1.89] and 1.44 [95% confidence interval, 1.25-1.67], respectively). All groups of women with anemia had increased odds of postpartum hemorrhage and decreased odds of delivering a small for gestational age neonate. There was no difference in composite neonatal morbidity.

CONCLUSION

Successful treatment of anemia with oral iron therapy was associated with a reduction in the odds of preterm birth and preeclampsia. Women with refractory anemia had similar outcomes to those who were untreated, emphasizing the importance of monitoring response to iron therapy during pregnancy.

Helicobacter pylori infection and micronutrient deficiency in pregnant women: a systematic review and meta-analysis

Background

Over the last few years, epidemiological studies have shown that infection with Helicobacter pylori has a major effect on micronutrient deficiency as well as on adverse pregnancy outcomes. Importantly, there are gaps in understanding the linkage of H. pylori infection with micronutrients deficiency in pregnant women.

Objective

We conducted a systematic review and meta-analysis to estimate the association between H. pylori infection and micronutrient deficiencies in pregnant women.

Methods

A systematic literature search was conducted for relevant articles using PubMed, Web of Science, and Scopus database from inception to March 2020. The OR with 95% CIs was determined by meta-analysis of data extracted from the selected studies.

Results

From 2384 primary articles, 6 studies were selected for systematic reviews and 4 studies distinctively (with 1274 participants: 553 cases and 721 controls) were selected for meta-analysis. The meta-analysed fixed effect model estimated the odds of having H. pylori infection was not significantly higher among pregnant women with micronutrient deficiencies than those without deficiencies (OR=1.12, 95% CI 0.88 to 1.42, p=0.37). In the subgroup analysis, no correlation was found between H. pylori infection and vitamin B₁₂ (OR=0.74, 95% CI 0.45 to 1.21, p=0.22), folate (OR=1.07, 95% CI 0.73 to 1.58, p=0.73), and ferritin (OR=0.81, 95% CI 0.51 to 1.31, p=0.4). However, a positive correlation was found between iron-deficiency anaemia (IDA) and H. pylori infection (OR=16.23, 95% CI 4.19 to 62.93, p<0.0001) during pregnancy.

Conclusion

H. pylori infection is associated with increased risk of IDA but not with deficiency of other micronutrients in pregnancy.

PROSPERO registration number

CRD42019135683.

Hyperemesis Gravidarum in First-Trimester Pregnant Saudi Women: Is Helicobacter pylori a Risk Factor?

Introduction

Hyperemesis gravidarum (HG) is a serious complication of pregnancy involving nausea and vomiting which affects all facets of the lives of many women. Helicobacter pylori infection has been linked to HG in some regions of the world. However, the prevalence of H. pylori in Saudi Arabian pregnant women and its link to HG has not been the subject of previous research. Detecting and treating H. pylori infection in women early in their pregnancies may lower the likelihood of adverse maternal outcomes. This study aims to assess the connection between the pathogenesis of HG and H. pylori infection in this population.

Methods

Forty-five pregnant women with HG were recruited from the outpatient clinic for antenatal care in the Gynecology and Obstetrics Department at King Abdulaziz University Hospital. Forty-five pregnant women without HG were matched as controls. Both groups underwent testing for the H. pylori antigen in stool samples.

Results

A statistically significant difference (P < 0.05) was observed between the cases and controls in terms of the occurrence of H. pylori. Thirty-eight women in the HG group (84.4%) tested positive for H. pylori, while the same was true of only 20 of the controls (44.4%). The mean level of blood hemoglobin in positive cases was significantly lower than that in negative cases (9.56 ± 1.29 vs. 11.90 ± 1.18 g/dl, P = 0.012).

Conclusion

H. pylori may play a contributing role in the presence of HG in the study population. It may be included with other investigations of HG, especially with cases that do not respond to conventional management and continue into the second trimester. Women with H. pylori were also more likely to suffer from anemia compared to those without the infection. For this reason, those working with pregnant women should pay close attention to those infected with H. pylori. Additional large case–control studies are necessary to better understand the part H. pylori plays and the pathogenesis of HG.

Sero-prevalence of Helicobacter pylori CagA immunoglobulin G antibody, serum pepsinogens and haemoglobin levels in adults

Associations observed of Helicobacter pylori infection with haemoglobin levels are inconsistent. We examined associations of H. pylori sero-prevalence and serum pepsinogens (PGs), as non-invasive markers of atrophic gastritis, with haemoglobin levels. A cross-sectional study was undertaken among 654 Jewish and 937 Arab residents of Jerusalem, aged 25–78 years, randomly selected from Israel’s national population registry in age-sex and population strata. Sera were tested for H. pylori IgG, cytotoxin–associated gene A (CagA) antigen IgG antibody and PGs levels. Multivariable models were fitted to account for confounders. Participants with atrophic gastritis (PGI < 30 μg/L or a PGI: PGII < 3.0) had lower haemoglobin levels than those without: beta-coefficient −0.34 (95% CI −0.59, −0.09); in men −0.27 (95% CI −0.67, 0.12), and in women −0.43 (95% CI −0.74, −0.12). Lower haemoglobin levels were noted in persons with CagA antibody than in those H. pylori sero-negative or H. pylori-CagA sero-negative: beta-coefficient −0.14 (95% CI −0.29, 0.01). Anaemia was more common among women and men with than without atrophic gastritis: adjusted OR 2.58 (95% CI 1.48, 4.48) and 1.52 (95% CI 0.59, 3.95), respectively. In conclusion, independent of known correlates, atrophic gastritis and apparently CagA sero-positivity, a marker of H. pylori virulent strains, are associated with lower haemoglobin levels.

Helicobacter pylori associated to unexplained or refractory iron deficiency anemia: an Egyptian single-center experience

Background

Refractory or unexplained iron deficiency anemia accounts for about 15% of all cases. The endoscopic gastrointestinal workup sometimes fails to establish the cause of iron deficiency anemia and a considerable proportion of patients regardless of risk category fail to respond to oral iron supplementation. The aim of the present study was to assess the etiological role of Helicobacter pylori infection in adult Egyptian patients with unexplained or refractory iron deficiency anemia.

Methods

A case controlled study was composed of 104 iron deficiency anemia cases and 70 age- and gender-matched healthy controls. Patients were diagnosed with iron deficiency anemia according to hemoglobin, mean corpuscular volume, serum ferritin, and transferrin saturation. Upper and lower endoscopies were performed and active H. pylori infection was investigated by testing for the H. pylori antigen in stool specimens. Hematological response to H. pylori treatment with triple therapy together with iron therapy (n = 32) or only iron therapy (n = 32) were assessed in patients with H. pylori infection.

Results

H. pylori infection was more prevalent in patients with unexplained or refractory iron deficiency anemia (61.5%). Of the different hematological parameters investigated, there was a significant correlation only between H. pylori infection and mean corpuscular volume (p-value 0.046). Moreover, there was a significant correlation between receiving triple therapy together with iron supplementation and improvements in the hematological parameters [hemoglobin (p-value < 0.001), mean corpuscular volume (p-value < 0.001), iron (p-value < 0.001) and serum ferritin (p-value < 0.001)] compared to receiving iron supplementation alone.

Conclusions

Failing to test for H. pylori infection could lead to a failure to identify a treatable cause of anemia and could lead to additional and potentially unnecessary investigations. Furthermore, treatment of H. pylori infection together with iron supplementation gives a more rapid and satisfactory response.

Unexplained iron deficiency anemia: does Helicobacter pylori have a role to play?

Background and aim

Testing for Helicobacter pylori (Hp) infection is recommended for work-up of unexplained iron deficiency anemia (IDA), although the evidence supporting this recommendation is scant. The aim of this study was to investigate the association between Hp infection and unexplained iron deficiency (ID) or IDA in the older adult population without significant upper gastrointestinal source of blood loss.

Methods

Retrospective single-center cohort study; 523 out of 1253 consecutive patients who underwent esophagogastroduodenoscopy with no significant upper and/or lower gastrointestinal source for blood loss or risk factors for IDA. Comparisons were made between the Hp-positive and Hp-negative groups using Fisher exact test, chi-square test and Student’s t-test. Univariate and multiple logistic regression analyses were used to identify significant risk factors associated with ID and IDA.

Results

One hundred and three subjects (19.7%) had Hp infection and 420 (80.3%) were negative for Hp. Sixty-eight (22.1%) out of 307 subjects with available serum iron profile had unexplained ID and 28 (5.4%) out of 510 subjects with available hemoglobin profile had unexplained IDA. No association was found between ID/IDA and Hp infection in univariate and multiple logistic regression analyses.

Conclusion

We found no association between unexplained ID or IDA and Hp infection in older adult population without peptic ulcer disease or significant upper gastrointestinal source of blood loss.

An updated systematic review and meta-analysis on the association between Helicobacter pylori infection and iron deficiency anemia

BACKGROUND

We conducted an updated systematic review and meta-analysis to examine the prevalence of depleted iron stores among persons infected with Helicobacter pylori compared to uninfected ones. We also assessed the impact of anti-H. pylori eradication therapy plus iron therapy on ferritin and hemoglobin levels compared to iron therapy alone.

METHODS

A literature search was conducted using the databases Medline, the Cochrane Library, Cochrane Central Register of Controlled Trials, EMBASE, and the Science Citation Index Expanded. Observational studies with methodological quality score of 13 (median score) and above, on a scale of 0-16, and all randomized controlled trials (RCTs) were eligible for the meta-analyses. Pooled point estimates and 95% confidence intervals (CI) were obtained using the random effects model.

RESULTS

Compared to uninfected persons, H. pylori-infected individuals showed increased likelihood of iron deficiency anemia (14 observational studies); pooled OR 1.72 (95% CI 1.23-2.42); iron deficiency (pooled OR 1.33; 95% CI 1.15-1.54; 30 studies); and anemia (pooled OR 1.15; 95% CI 1.00-1.32; 23 studies). Meta-analyses of seven RCTs showed increased ferritin, standardized mean difference (SMD) 0.53 (95% 0.21-0.85), but not hemoglobin, SMD 0.36 (95% -0.07 to 0.78), Pv=.1, following anti-H. pylori eradication therapy plus iron therapy as compared with iron therapy alone. Significant heterogeneity was found among studies, as well as evidence of publication bias.

CONCLUSIONS

Current evidence indicates increased likelihood of depleted iron stores in relation to H. pylori infection. H. pylori eradication therapy, added to iron therapy, might be beneficial in increasing ferritin and hemoglobin levels.

The aetiology of anaemia during pregnancy: a study to evaluate the contribution of iron deficiency and common infections in pregnant Ugandan women

Objective

To describe the aetiology of anaemia in pregnant Ugandan women and explore Fe deficiency and common infections as contributors to anaemia in this population.

Design

Cross-sectional study in which Hb, ferritin, transferrin receptor (sTfR), C-reactive protein, α-1 acid glycoprotein, hepcidin, malaria, hookworm infestation, syphilis and Helicobacter pylori infection were assessed.

Setting

Antenatal care clinic at Kawempe Health Centre, Kampala, Uganda.

Subjects

HIV-negative women (n 151) in their first or second pregnancy at 10–16 weeks’ gestation.

Results

The prevalence of anaemia was 29·1 %. Fe deficiency was 40·4 % and 14·6 % based on ferritin <30 μg/l and on adjusted ferritin <12 μg/l respectively, and 6·6 % based on sTfR >8·3 μg/ml. The prevalence of Fe-deficiency anaemia was 9·3 % based on ferritin <30 μg/l, 6·6 % based on adjusted ferritin <12 μg/l and 4·3 % based on sTfR >8·3 μg/ml. Hepcidin concentration was positively correlated with ferritin concentration (n 151, r=0·578, P<0·00001). H. pylori infection was highly prevalent (70 %) while malaria, hookworm infestation and syphilis were not common. Of all women, 60·3 % had α-1 acid glycoprotein >1 g/l and/or C-reactive protein >5 mg/l. Malaria parasitaemia (OR=6·85; 95 % CI 1·25, 37·41, P=0·026) and Fe deficiency defined using sTfR (OR=5·58; 95 % CI 1·26, 24·80, P=0·024) were independently and positively associated with anaemia. Population-attributable risk factors for anaemia for raised C-reactive protein, Fe deficiency defined by sTfR >8·3 μg/ml and presence of malaria parasites were 41·6 (95 % CI 11·1, 72·2) %, 13·5 (95 % CI 2·0, 25·0) % and 12·0 (95 % CI 1·4, 22·6) %, respectively.

Conclusions

Infections and inflammation are of greater significance than Fe deficiency in the aetiology of anaemia in pregnant Ugandan women during the first trimester.

Helicobacter pylori infection in pregnant women in four districts of Uganda: role of geographic location, education and water sources

BACKGROUND

The prevalence of Helicobacter pylori infection varies in relation to geography, ethnicity and socioeconomic factors. Available data on the prevalence of Helicobacter pylori infection in Uganda are not representative of the general population. We sought to describe the epidemiology of this infection in pregnant women in Uganda to provide background data for a study into the effect of H. pylori infection during pregnancy on the hematological response to iron supplementation.

METHODS

Using a cross-sectional design, H. pylori infection was assessed by the stool antigen test among 447 pregnant women attending antenatal care clinics in Apac, Mbale, Mbarara and Rakai Districts which are in different geographical regions in Uganda, and at Kawempe Health Center which serves a low-income densely populated area in Kampala City. Socio-demographic and household data were collected by face-to-face interviews using a questionnaire. Associations between H. pylori infection and socio-demographic and household characteristics were analyzed using logistic regression.

RESULTS

The overall prevalence of H. pylori infection was 45.2% but varied by geographical location from 18.2% in Apac District to 60.5% at Kawempe Health Centre. At 18.4%, the Langi ethnic group, who were enrolled exclusively in Apac District, had the lowest prevalence of H. pylori infection while the Gisu had the highest prevalence (58.4%). H. pylori was independently associated with enrollment at clinics not in Apac (adjusted OR = 5.68; 95% CI: 3.02-10.7) and with using water from public wells, boreholes or springs (AOR = 3.20; 95% CI: 1.19-8.61) and from rivers, lakes or streams (AOR = 5.20; 95% CI: 1.58-17.05). Urban residence (AOR = 1.71; 95% CI: 1.13-2.60) and no formal education (AOR = 1.95; 95% CI: 1.03-3.67) were also independently associated with H. pylori infection.

CONCLUSIONS

The unexpected variation in the prevalence of H. pylori infection in Uganda calls for population-based studies in the region and offers an opportunity to study the transmission dynamics of H. pylori infection. The association between H. pylori infection and surface water sources for household use suggests waterborne transmission of H. pylori infection highlighting the need for concerted efforts in environmental health in communities and at the household level.

Helicobacter pylori and pregnancy-related disorders

Helicobacter pylori (H. pylori) infection is investigated in gastric diseases even during pregnancy. In particular, this Gram-negative bacterium seems to be associated with hyperemesis gravidarum, a severe form of nausea and vomiting during pregnancy. During the last decade, the relationship among H. pylori and several extra-gastric diseases strongly emerged in literature. The correlation among H. pylori infection and pregnancy-related disorders was mainly focused on iron deficiency anemia, thrombocytopenia, fetal malformations, miscarriage, pre-eclampsia and fetal growth restriction. H. pylori infection may have a role in the pathogenesis of various pregnancy-related disorders through different mechanisms: depletion of micronutrients (iron and vitamin B₁₂) in maternal anemia and fetal neural tube defects; local or systemic induction of pro-inflammatory cytokines release and oxidative stress in gastrointestinal disorders and pre-eclampsia; cross-reaction between specific anti-H. pylori antibodies and antigens localized in placental tissue and endothelial cells (pre-eclampsia, fetal growth restriction, miscarriage). Since H. pylori infection is most likely acquired before pregnancy, it is widely believed that hormonal and immunological changes occurring during pregnancy could activate latent H. pylori with a negative impact not only on maternal health (nutritional deficiency, organ injury, death), but also on the fetus (insufficient growth, malformation, death) and sometime consequences can be observed later in life. Another important issue addressed by investigators was to determine whether it is possible to transmit H. pylori infection from mother to child and whether maternal anti-H. pylori antibodies could prevent infant’s infection. Studies on novel diagnostic and therapeutic methods for H. pylori are no less important, since these are particularly sensitive topics in pregnancy conditions. It could be interesting to study the possible correlation between H. pylori infection and other pregnancy-related diseases of unknown etiology, such as gestational diabetes mellitus, obstetric cholestasis and spontaneous preterm delivery. Since H. pylori infection is treatable, the demonstration of its causative role in pregnancy-related disorders will have important social-economic implications.

Helicobacter pylori and anemia with pregnancy

SUBJECTS AND METHODS

Study was conducted in Ain Shams University hospitals on 100 pregnant women with iron-deficiency anemia (IDA), including 50 cases infected with Helicobacter pylori (H. pylori) and 50 cases negative for H. pylori infection. Cases with symptomatic gastritis or hyperemesis gravidarum were not included in the study, obstetric history, sociodemographic and dietary variables were also assessed. Hemoglobin level, serum iron, serum ferritin, total iron binding capacity (TIBC), H. pylori serum antibody, stool analysis to exclude parasitic infection causing IDA, occult blood in stool and ultrasound for the fetus to ensure its cardiac pulsations and to exclude any associated abnormality were all done for all patients. Iron therapy in a fixed dose was given to all patients for 1 month. Response was estimated and statistical comparison was done between both groups. Eradication of H. pylori was done in positive cases by triple therapy in the second trimester and iron therapy was given after treatment in the same dose for another month. Their response to treatment after eradication was compared to their response to iron therapy prior to H. pylori eradication.

RESULTS

Hb levels, serum iron, serum ferritin were lower and TIBC was higher in H. pylori-infected cases than negative ones. The average rise of Hb in cases negative to H. pylori was higher than those positive to H. pylori. After comparing response of cases infected with H. pylori to iron therapy before and after eradication of H. pylori, it was found that rise of Hb was higher after treatment than before eradication of H. pylori.

CONCLUSION

Response to iron therapy in cases of iron deficiency anemia in patients without H. pylori infection was better than those infected with H. pylori. H. pylori eradication in the infected cases increased their response to iron therapy.

Survey of anaemia and Helicobacter pylori infection in adolescent girls in Suihua, China and enhancement of iron intervention effects by H. pylori eradication

In the present study, we investigated the prevalence of anaemia and Fe deficiency anaemia (IDA) and explored the relationship between Helicobacter pylori infection and IDA in adolescent girls. A total of 1037 adolescent girls from Suihua, China were enrolled. Hb, serum ferritin (SF), serum transferrin receptor (sTfR) and serum IgG antibodies to H. pylori were measured. Participants with IDA and co-existing H. pylori infection (n 80) who had an intake of >25 mg/d of Fe were assigned randomly to the intervention and control groups. Patients in the intervention group were administered a 12-week course of oral EDTA-Na-Fe (60 mg Fe/dose, three times a week) and a 2-week course of colloidal bismuth subcitrate, amoxicillin and metronidazole. Subjects in the control group were administered EDTA-Na-Fe alone. Hb, SF and sTfR were reassessed 3 months after the 12-week regimen ended. Prevalence of anaemia, Fe deficiency (defined as SF < 12·0 μg/l), IDA and H. pylori infection in the population of 1037 was 19.5, 40.4, 17.1 and 31.2 %, respectively. The prevalence of H. pylori infection in the IDA group was 46.9 %, while the non-anaemic group had 28.1 % prevalence. A significant increase in Hb and SF and a decrease in sTfR value were found in the intervention group and the H. pylori-negative group. Findings suggest that IDA is still one of the prominent problems in adolescent girls. There is an association between H. pylori infection and IDA. Treatment of H. pylori infection is associated with a more rapid response to oral Fe therapy.

The positivity of Helicobacter pylori Stool Antigen in patients with Hyperemesis gravidarum

OBJECTIVE

We aimed to investigate the possible association between Helicobacter pylori infection and Hyperemesis gravidarum.

MATERIAL AND METHODS

Thirty-six pregnant women with Hyperemesis gravidarum with severe vomiting (more than 4 times a day), weight loss (≥3 kg), ketonuria and 36 pregnant women gestational age-matched, without nausea and vomiting attending our outpatient clinic for antenatal care were enrolled the study. Demographic data of the patients were registered. Blood samples for hemogram, serum electrolytes (sodium, potassium, chloride, and calcium), alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatine, thyroid stimulating hormone (TSH), free T3-T4, total T3-T4, and urine samples for ketonuria, stool samples for HpSA were studied. The data of both groups were compared.

RESULTS

Eight Hyperemesis gravidarum patients (22.2%) and 1 control patient (2.8%) were established HpSA positive and it was statistically significant (p:0.037). There was no significant difference between Hyperemesis gravidarum and control subjects in terms of age, gestational week, parity, educational level, socioeconomic status and smoking. There was anemia in 5 Hyperemesis gravidarum patients, 4 of them were HpSA positive. HpSA positivity was more prevalent in Hyperemesis gravidarum patients with anemia (p=0.003). Severe vomiting (more than 4 times a day), heartburn, epigastric pain, duration of hospitalization (more than 4 days) and weight loss (≥5 kg) were not correlated to HpSA positivity.

CONCLUSION

The pregnant women with Hyperemesis gravidarum have a significantly higher prevalence of Helicobacter pylori compared with control subjects.

Geographic and racial patterns of anemia prevalence among low-income Alaskan children and pregnant or postpartum women limit potential etiologies

OBJECTIVES

The etiology of the 10-fold increase in anemia and iron deficiency prevalence among Alaska Native individuals from the culturally traditional southwestern/northern Alaska regions remains unknown. The present study sought to determine anemia prevalence among people enrolled in the Alaska Women, Infant, and Children (WIC) program and reconcile results with etiological hypotheses, particularly nutritional iron deficiency and Helicobacter pylori infection.

PATIENTS AND METHODS

An analysis was conducted of 50,964 children 6 to 59 months of age and 30,154 pregnant or postpartum women enrolled in WIC during 1999 to 2006. Based on 3 regional groupings of residence and Alaska Native status, 6 strata were defined.

RESULTS

Southwestern/northern Alaska Native children-who are known to have high nutritional iron intake based on subsistence diets-had the highest anemia prevalence (35%). However, southwestern/northern residence increased anemia risk similarly for Alaska Native (relative risk 1.6) and non-Native (relative risk 1.5) children. Anemia prevalence was highest among the youngest children and declined with increasing age at approximately the same rate regardless of race or residence. Alaska Native pregnant or postpartum women from all of the regions had higher anemia prevalences than non-Native women; southwestern/northern residence conferred additional risk to Alaska Native women.

CONCLUSIONS

A region-specific environmental factor is supported by the increased risk seen among all of the children residing in the southwestern/northern regions. However, the observed patterns make nutritional iron deficiency or H pylori infection unlikely as the sole or major etiologies of the high anemia prevalences observed in some groups.

Helicobacter pylori is not associated with anaemia in Latin America: results from Argentina, Brazil, Bolivia, Cuba, Mexico and Venezuela

OBJECTIVE

To investigate the association between Helicobacter pylori infection and anaemia.

DESIGN

Six cross-sectional studies. H. pylori infection was assessed by the [13C]urea breath test using MS or IR analysis. Hb was measured for all countries. Ferritin and transferrin receptors were measured for Argentina, Bolivia, Mexico, and Venezuela.

SETTING

Health services in Argentina, Brazil and Mexico or public schools in Bolivia, Cuba and Venezuela.

SUBJECTS

In Argentina, 307 children aged 4-17 years referred to a gastroenterology unit; in Bolivia, 424 randomly selected schoolchildren aged 5-8 years; in Brazil, 1007 adults (157 men, 850 women) aged 18-45 years attending thirty-one primary health-care units; in Cuba, 996 randomly selected schoolchildren aged 6-14 years; in Mexico, seventy-one pregnant women in their first trimester attending public health clinics; in Venezuela, 418 children aged 4-13 years attending public schools.

RESULTS

The lowest prevalence of H. pylori found was among children in Argentina (25.1%) and the highest in Bolivia (74.0%). In Bolivia, Cuba and Venezuela children showed similar prevalence of H. pylori infection as in Brazilian and Mexican adults (range 47.5% to 81.8%). Overall anaemia prevalence was 11.3% in Argentina, 15.4% in Bolivia, 20.6% in Brazil, 10.5% in Cuba and 8.9% in Venezuela. Adjusted analyses allowing for confounding variables showed no association between H. pylori colonization and anaemia in any study. Hb, ferritin and transferrin receptor levels were also not associated with H. pylori infection in any country.

CONCLUSIONS

The present study showed no evidence to support the hypothesis that H. pylori contributes to anaemia in children, adolescents, adults or pregnant women in six Latin American countries.

Helicobacter pylori infection and iron stores: a systematic review and meta-analysis

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.

Unexpectedly low prevalence of Helicobacter pylori infection among pregnant women on Pemba Island, Zanzibar

Helicobacter pylori is strongly associated with peptic ulcer and gastric cancer and may be the most common human bacterial infection. The epidemiology of H. pylori has been poorly studied in Africa, where its relevance to disease has not been fully appreciated. Following a cross-sectional study design, H. pylori infection was measured by (13)C-urea breath test among 857 pregnant women attending antenatal care clinics. Location, water use practices, anthropometry, and social and demographic variables were assessed as covariates. The prevalence of H. pylori infection was 17.5%. Multiple logistic regression showed that H. pylori was positively associated with location of enrollment clinic along the main road leading from the southern seaport (odds ratio (OR)=2.5), presence of costlier household lighting in the home (OR=1.6) and height (10 cm) (OR=1.5). The prevalence of H. pylori infection was unexpectedly low for a developing country population, where prevalence is typically very high. Higher prevalence along the road from the southern seaport suggests that infection was imported from the mainland. The reason for very low prevalence should be investigated further because the discovery of bacterial or dietary factors that limit infection in this population could have useful public health applications.

Extragastric diseases associated with Helicobacter pylori infection

This paper critically reviews the current literature on extragastric diseases associated with Helicobacter pylori infection, with an emphasis on methodologic issues that complicate interpretation of study findings. This review reveals common study limitations and overall uncertainty that H. pylori infection plays a role in extragastric diseases, although such a role has not been clearly ruled out for specific diseases of relevance. Evidence suggests that anti-H. pylori therapy may lead to improvement of a few extragastric diseases, in particular, idiopathic thrombocytopenic purpura, iron deficiency anemia, and chronic idiopathic urticaria, but the data from randomized controlled trials are insufficient to confirm this beneficial effect; if the benefit of anti-H. pylori therapy for specific diseases is real, it is not clear if it results from removing H. pylori-specific injurious effects, eliminating some other infectious pathogen, or reducing the total infectious burden.

Helicobacter felis infection causes an acute iron deficiency in nonpregnant and pregnant mice

BACKGROUND

The role of Helicobacter pylori infection in iron deficiency during pregnancy is limited. The aim of the present study was to assess the relationship between Helicobacter infection and levels of iron stores in pregnant mice.

MATERIALS AND METHODS

Female C57BL/6 mice were either inoculated with 10(8) H. pylori, Helicobacter felis or water. In the nonpregnant study, 15 mice from each group were sacrificed after 4 and 20 weeks of infection. In the pregnancy study, after 6 weeks of infection all female mice were mated and approximately 2 weeks after mating, half of the pregnant mice (n = 9/group) from each group were sacrificed. The remaining mice were allowed to give birth, and approximately 4 weeks after birth, mice were asphyxiated with CO2, followed by heart puncture, and killed by cervical dislocation. Serum ferritin and iron were determined with a micro-particle enzyme immunoassay method and by a timed-endpoint method.

RESULTS

Serum iron levels in mice infected with H. felis were significantly (p < .05) lowered compared to control (24%) and H. pylori (27%)-infected mice at 4 weeks of infection. Serum iron in the control, H. pylori and H. felis groups were significantly (p < .05) elevated at 20 weeks by 39, 26 and 77%, respectively, compared to 4 weeks of infection. H. felis-infected mice had a significantly (p < .05) decreased serum ferritin level during pregnancy (61%) compared to H. pylori-infected mice.

CONCLUSION

These results suggest that H. felis but not H. pylori infection causes an acute iron deficiency in normal and pregnant mice.

Iron deficiency and Helicobacter pylori infection in the United States

Using data from the current National Health and Nutrition Examination Survey (1999-2000), the authors assessed whether Helicobacter pylori infection is associated with iron deficiency and iron-deficiency anemia (IDA) in the United States. Iron deficiency was defined as at least two abnormal results out of three biomarkers of iron stores. IDA was defined as a low hemoglobin level in the presence of iron deficiency. H. pylori infection was measured by serology. Complex survey estimators were used in the analysis. For 7,462 survey participants aged >or=3 years, H. pylori infection was associated with decreased serum ferritin levels (percent change = -13.9%, 95% confidence interval (CI): -19.5, -8.0) but not with levels of free erythrocyte protoporphyrin, transferrin saturation, or hemoglobin (percent change = 1.5%, -2.8%, and -1.1%, respectively). Multinomial logistic regression analyses indicated that H. pylori infection was associated with the prevalence of IDA (prevalence odds ratio (POR) = 2.6, 95% CI: 1.5, 4.6) and, to a lesser degree, other types of anemia (POR = 1.3, 95% CI: 1.0, 1.7). H. pylori infection was associated with a 40% increase in the prevalence of iron deficiency (POR = 1.4, 95% CI: 0.9, 2.0) after controlling for relevant covariates. In the United States, H. pylori infection was associated with iron deficiency/IDA regardless of the presence or absence of peptic ulcer disease.

Helicobacter pylori and extragastric diseases--other Helicobacters

The involvement of Helicobacter pylori in the pathogenesis of extragastric diseases continues to be an interesting topic in the field of Helicobacter-related pathology. Although conflicting findings have been reported for most of the disorders, a role of H. pylori seems to be important especially for the development of cardiovascular and hematologic disorders. Previously isolated human and animal Helicobacter sp. flexispira and "Helicobacter heilmannii" strains have been validated using polyphasic taxonomy. A novel enterohepatic Helicobacter has been isolated from mastomys and mice, adding to the list of helicobacters that colonize the liver. Genetic targets that may aid the classification of novel Helicobacter species have emerged. Animal models of Helicobacter-induced gastric and hepatobiliary diseases have offered insights to the mechanisms associated with premalignant transformation.