AGA Technical Review on Gastrointestinal Evaluation of Iron Deficiency Anemia

Iron deficiency should not be accepted in patients with inflammatory bowel disease - a Scandinavian expert opinion

AIM

In this paper, we aim to explain the reason why iron deficiency (ID) is common in patients with inflammatory bowel disease (IBD), how to better apply diagnostic tools to uncover the state of ID as well as how to interpret the results, and not least, how to treat ID in this group of patients.

METHODS

This article is an expert review and opinion paper on a topic that is too often forgotten in clinical practice. We have not performed a systematic review, but we present the most important research allocated to the topic to substantiate an expert opinion.

RESULTS

This position paper summarises the pathophysiology of ID and gives recommendations on the monitoring and treatment of ID in IBD. ID with or without concurrent anaemia (IDA) is the most common systemic complication in patients with IBD, related to both disease activity and severity. It has consequences both for health-related quality of life and future course of disease of the IBD patient. Intravenous iron is an efficacious and well tolerated, but still underused, therapy for ID and IDA. Iron deficiency should be treated before symptoms of anaemia appear and quality of life is impacted. However, there is still limited awareness of how to detect and treat ID in clinical practice. Uncertainty regarding which diagnostic tests to use and how to interpret the results may also be responsible for variations in clinical practice. In addition, opinions on how to correct ID and IDA differ, in relation to both clinical efficacy and safety.

CONCLUSION

The consequences of ID in patients with IBD are significant. Guidelines on diagnosis, treatment and follow-up of ID should be implemented. IDA is a manifestation of severe ID and preventive strategies focusing on efficient treatment of ID regardless of the level of haemoglobin should therefore be explored.

Management of iron deficiency in children, adults, and pregnant individuals: evidence-based and expert consensus recommendations

Iron deficiency is the most common micronutrient deficiency worldwide. Oral iron is often recommended as first-line treatment, but there is no consensus on the optimal formulation, dosing strategy, or which patients should be treated preferentially with intravenous iron. To address these challenges, the Iron Consortium at Oregon Health & Science University (OHSU) convened an international panel of 26 experts in haematology, primary care, paediatrics, obstetrics, gastroenterology, cancer, and patient advocacy among its members. This panel was supplemented by insights from a four-person patient focus group to develop current recommendations using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. The panel developed clinically relevant questions in five priority topic areas, a systematic literature search was performed, and studies meeting a priori criteria were included to generate evidence tables for recommendation development. Evidence-based and expert opinion-based recommendations were made through a structured anonymous consensus voting process at an in-person meeting in Portland, OR, USA, hosted by OHSU on Feb 16-17, 2024. The expert panel made seven evidence-based recommendations for three demographic groups with iron deficiency: non-pregnant adults, pregnant individuals, and infants, children, and adolescents. Expert opinions supported the recommendations on 21 aspects of care for which there is insufficient evidence. This Review provides evidence-based recommendations and expert consensus on the diagnosis, treatment, and management of iron deficiency, detailing best practices for oral and intravenous iron repletion across diverse patient populations.

Small Bowel Tumors: A 7-Year Study in a Tertiary Care Hospital

(1) Background: Tumors of the small bowel represent 3-6% of gastrointestinal neoplasms and 3-6% of GI malignancies. The difficulties regarding the diagnosis are associated with larger tumors at the moment of the diagnosis and with advanced forms of malignant tumors, associated with a dismal prognosis. (2) Methods: We performed an observational, retrospective, cohort study that included patients with small bowel tumors admitted to the Craiova County Emergency Clinic Hospital between 1 January 2017 and 31 December 2023. The data were collected from the analysis of the patient's discharge documents from the Hippocrates computer system of the hospital and the evaluation of endoscopy databases. Patients under 16 years of age, those with no pathological confirmation of the malignancy, and those with insufficient data were excluded. (3) Results: A total of 80 cases of small bowel tumors were diagnosed; 72.5% were malignant, of which 10.3% were metastases. The most frequent primary malignant small bowel tumor was adenocarcinoma; two squamous cell carcinomas were noted. CT scans and upper digestive endoscopy represent the most frequent imaging methods for the diagnosis. The prognosis for malignant tumors was poor, with a 41% 5-year survival rate. (4) Conclusions: Small bowel tumors are rarely encountered, with 72.5% being malignant, and were diagnosed at large dimensions and in advanced stages for malignant tumors, with a dismal prognosis.

Iron Deficiency in Adults: A Review

Importance

Absolute iron deficiency, defined as low iron stores with or without anemia, affects approximately 2 billion people worldwide and 14% of adults in the US. Iron-deficiency anemia, defined as low hemoglobin due to low iron stores, affects approximately 1.2 billion people worldwide, including 10 million in the US.

Observations

Absolute iron deficiency progresses from low iron stores to iron-deficiency anemia. Individuals with nonanemic iron deficiency or iron-deficiency anemia may be asymptomatic or experience fatigue, irritability, depression, difficulty concentrating, restless legs syndrome (32%-40%), pica (40%-50%), dyspnea, lightheadedness, exercise intolerance, and worsening heart failure (HF). Symptom prevalences vary depending on age, comorbidities (eg, chronic kidney disease [CKD], HF), and severity and rate of development of iron deficiency. The most common causes of iron deficiency are bleeding (menstrual, gastrointestinal), impaired iron absorption (atrophic gastritis, celiac disease, bariatric surgical procedures), inadequate dietary iron intake, and pregnancy. In high-income countries, approximately 38% of nonpregnant, reproductive-age women have iron deficiency without anemia and about 13% have iron-deficiency anemia. During the third trimester of pregnancy, iron deficiency affects up to 84% of pregnant women, based on data from high-income countries. Additional risk factors include use of nonsteroidal anti-inflammatory drugs, inflammatory bowel disease (IBD [13%-90%]), and other chronic inflammatory conditions, such as CKD (24%-85%), HF (37%-61%), and cancer (18%-82%). Testing for iron deficiency is indicated for patients with anemia and/or symptoms of iron deficiency (fatigue, pica, or restless legs syndrome) and should be considered for those with risk factors such as heavy menstrual bleeding, pregnancy, or IBD. Iron deficiency is diagnosed by low serum ferritin (typically <30 ng/mL) in individuals without inflammatory conditions or by transferrin saturation (iron/total iron binding capacity × 100) less than 20%. Causes of iron deficiency should be identified and treated. Oral iron (ferrous sulfate 325 mg/d or on alternate days) is typically first-line therapy. Intravenous iron is indicated for patients with oral iron intolerance, poor absorption (celiac disease, post-bariatric surgical procedure), chronic inflammatory conditions (CKD, HF, IBD, cancer), ongoing blood loss, and during the second and third trimesters of pregnancy.

Conclusions and Relevance

Iron deficiency and iron-deficiency anemia are common conditions that may cause symptoms such as fatigue, exercise intolerance, and difficulty concentrating. Ferritin and/or transferrin saturation are required for diagnosis and screening. Oral iron is first-line therapy for most patients. Intravenous iron is used for individuals who do not tolerate or have impaired absorption of oral iron, those with ongoing blood loss, certain chronic inflammatory conditions (IBD, CKD, HF, cancer), and during the second and third trimesters of pregnancy.

Machine Learning Models With Prognostic Implications for Predicting Gastrointestinal Bleeding After Coronary Artery Bypass Grafting and Guiding Personalized Medicine: Multicenter Cohort Study

BACKGROUND

Gastrointestinal bleeding is a serious adverse event of coronary artery bypass grafting and lacks tailored risk assessment tools for personalized prevention.

OBJECTIVE

This study aims to develop and validate predictive models to assess the risk of gastrointestinal bleeding after coronary artery bypass grafting (GIBCG) and to guide personalized prevention.

METHODS

Participants were recruited from 4 medical centers, including a prospective cohort and the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. From an initial cohort of 18,938 patients, 16,440 were included in the final analysis after applying the exclusion criteria. Thirty combinations of machine learning algorithms were compared, and the optimal model was selected based on integrated performance metrics, including the area under the receiver operating characteristic curve (AUROC) and the Brier score. This model was then developed into a web-based risk prediction calculator. The Shapley Additive Explanations method was used to provide both global and local explanations for the predictions.

RESULTS

The model was developed using data from 3 centers and a prospective cohort (n=13,399) and validated on the Drum Tower cohort (n=2745) and the MIMIC cohort (n=296). The optimal model, based on 15 easily accessible admission features, demonstrated an AUROC of 0.8482 (95% CI 0.8328-0.8618) in the derivation cohort. In external validation, the AUROC was 0.8513 (95% CI 0.8221-0.8782) for the Drum Tower cohort and 0.7811 (95% CI 0.7275-0.8343) for the MIMIC cohort. The analysis indicated that high-risk patients identified by the model had a significantly increased mortality risk (odds ratio 2.98, 95% CI 1.784-4.978; P<.001). For these high-risk populations, preoperative use of proton pump inhibitors was an independent protective factor against the occurrence of GIBCG. By contrast, dual antiplatelet therapy and oral anticoagulants were identified as independent risk factors. However, in low-risk populations, the use of proton pump inhibitors (χ21=0.13, P=.72), dual antiplatelet therapy (χ21=0.38, P=.54), and oral anticoagulants (χ21=0.15, P=.69) were not significantly associated with the occurrence of GIBCG.

CONCLUSIONS

Our machine learning model accurately identified patients at high risk of GIBCG, who had a poor prognosis. This approach can aid in early risk stratification and personalized prevention.

TRIAL REGISTRATION

Chinese Clinical Registry Center ChiCTR2400086050; http://www.chictr.org.cn/showproj.html?proj=226129.

The Diagnostic Yield of Video Capsule Endoscopy for Uncomplicated Asymptomatic Iron Deficiency Anemia With Negative Bidirectional Endoscopy in a Large Military Gastroenterology Program

BACKGROUND

 Iron-deficiency anemia (IDA) often results from gastrointestinal (GI) bleeding. Video capsule endoscopy (VCE) is increasingly used to investigate suspected small bowel bleeding, particularly when bidirectional endoscopy is nondiagnostic. However, the diagnostic yield of VCE in asymptomatic patients with IDA and negative bidirectional endoscopy is not well-established, leading to variability in clinical guidelines.

METHODS

We conducted a retrospective review of patients at Brooke Army Medical Center who underwent VCE from January 2019 to April 2023 following negative bidirectional endoscopy for IDA, defined as ferritin <45 ng/mL. We analyzed demographic data, VCE findings, and outcomes, including need for further intervention, persistence of IDA, and hospitalizations. We also assessed the impact of referral delays on outcomes.

RESULTS

Out of 238 patients, 75 met the inclusion criteria. VCE revealed abnormal findings in 36% of cases, with 8% having actionable findings necessitating repeat endoscopy. The most common abnormality was small bowel angiodysplasias. No small bowel malignancies were detected. Patients aged over 65 had a higher rate of abnormal findings and actionable lesions. Delays in subspecialty evaluation (>180 days) did not significantly affect patient outcomes.

CONCLUSION

In asymptomatic IDA patients with negative bidirectional endoscopy, VCE demonstrates a 36% diagnostic yield, primarily identifying small bowel angiodysplasias, with limited impact on detecting malignancies. This study highlights the importance of individualizing VCE use to each patient, and suggests that delays in referral do not adversely affect outcomes. Further prospective studies are needed to refine diagnostic guidelines and enhance cost-effectiveness.

Mistakes in the management of iron deficiency anaemia: a narrative review

INTRODUCTION

Anaemia occurs due to an imbalance between erythrocyte production and loss. This imbalance can be due to ineffective erythropoiesis, blood loss or haemolysis. Whilst there are many causes for anaemia, iron deficiency anaemia (IDA) remains the predominant cause worldwide.

AREAS COVERED

There have been many updated guidelines on the management of IDA in the past few years. As the reasons for IDA are many, evaluation requires thorough analysis and focused investigations. As an asymptomatic disease in the early stages, IDA can lead to many mistakes in its management. This review highlights potential mistakes in assessing and managing IDA and recommendations to avoid them.

CONCLUSION

The effective management of IDA necessitates a comprehensive and multidisciplinary approach. By recognising and addressing the common mistakes highlighted in this narrative review, healthcare professionals can improve patient outcomes, minimise complications, and enhance the overall quality of care.

Absolute and functional iron deficiency: Biomarkers, impact on immune system, and therapy

Iron is essential for numerous physiological processes and its deficiency often leads to anemia. Iron deficiency (ID) is a global problem, primarily affecting reproductive-age women and children, especially in developing countries. Diagnosis uses classical biomarkers like ferritin or transferrin saturation. Recent advancements include using soluble transferrin receptor (sTfR) or hepcidin for improved detection and classification of absolute and functional iron deficiencies, though mostly used in research. ID without anemia may present symptoms like asthenia and fatigue, even without relevant clinical consequences. ID impacts not only red-blood cells but also immune system cells, highlighting its importance in global health and immune-related comorbidities. Managing ID, requires addressing its cause and selecting appropriate iron supplementation. Various improved oral and intravenous products are available, but further research is needed to refine treatment strategies. This review updates on absolute and functional iron deficiencies, their relationships with the immune system and advancements in diagnosis and therapies.

Faecal immunochemical tests can improve colonoscopy triage in patients with iron deficiency: A systematic review and meta-analysis

BACKGROUND

Use of the faecal immunochemical test (FIT) to triage patients with iron deficiency (ID) for colonoscopy due to suspected colorectal cancer (CRC) may improve distribution of colonoscopic resources. We reviewed the diagnostic performance of FIT for detecting advanced colorectal neoplasia, including CRC and advanced pre-cancerous neoplasia (APCN), in patients with ID, with or without anaemia.

METHODS

We performed a systematic review of three databases for studies comprising of patients with ID, with or without anaemia, completing a quantitative FIT within six months prior to colonoscopy, where test performance was compared against the reference standard colonoscopy. Random effects meta-analyses determined the diagnostic performance of FIT for advanced colorectal neoplasia.

RESULTS

Nine studies were included on a total of n=1761 patients with ID, reporting FIT positivity thresholds between 4-150 µg haemoglobin/g faeces. Only one study included a non-anaemic ID (NAID) cohort. FIT detected CRC and APCN in ID patients with 90.7 % and 49.3 % sensitivity, and 81.0 % and 82.4 % specificity, respectively. FIT was 88.0 % sensitive and 83.4 % specific for CRC in patients with ID anaemia at a FIT positivity threshold of 10 µg haemoglobin/g faeces.

CONCLUSIONS

FIT shows high sensitivity for advanced colorectal neoplasia and may be used to triage those with ID anaemia where colonoscopic resources are limited, enabling those at higher risk of CRC to be prioritised for colonoscopy. There is a need for further research investigating the diagnostic performance of FIT in NAID patients.

Diagnostic yield of bidirectional endoscopy for iron deficiency anemia in young patients

BACKGROUND

While bidirectional endoscopy is recognized as the standard approach for investigating iron deficiency anemia (IDA) in men older than 45 and postmenopausal women, evidence supporting the application of this approach in younger men and premenopausal women is scarce in the absence of symptoms. Our primary aim is to identify the diagnostic yield of bidirectional endoscopy in men younger than 45 and premenopausal women, and describe the clinical characteristics of those with significant endoscopic and pathology-proven findings.

METHODS

We performed a retrospective chart review including patients younger than age 45 with IDA who underwent esophagogastroduodenoscopy (EGD) and/or colonoscopy at the Brooklyn VA Hospital between 2009 and 2023. Demographic, clinical, and endoscopic patient data was all collected, stratified, analyzed, and interpreted.

RESULTS

In 143 patients younger than age 45 with IDA, 28.6% were found to have positive upper gastrointestinal (GI) findings, of which 70.3% were pathology-proven H. pylori cases. 57.9% of patients reported upper GI symptoms, while 42.9% of patients were asymptomatic. In total, 18.2% of symptomatic patients were found to have clinically significant findings on EGD as compared with 42.9% of asymptomatic patients. Additionally, 9.1% of symptomatic patients were found to have biopsy proven H. pylori-associated gastritis or duodenitis as compared with 33.9% of asymptomatic patients. Of the patients who underwent colonoscopy, 8.3% were found to have lower GI lesions.

CONCLUSIONS

We found the diagnostic yield of EGD to be significantly higher than that of colonoscopy in younger IDA patients. Our findings suggest current guidelines are clinically relevant to the young patient cohort. Our study also found asymptomatic IDA patients below age 45 to have a significantly higher diagnostic yield of EGD as compared to symptomatic IDA patients within the same age cohort. The differences in diagnostic yields may be a result of symptomatic patients being more likely to have been prescribed proton pump inhibitors or histamine receptor antagonists prior to endoscopy.

AGA Clinical Practice Update on Management of Iron Deficiency Anemia: Expert Review

DESCRIPTION

In this Clinical Practice Update (CPU), we will Best Practice Advice (BPA) guidance on the appropriate management of iron deficiency anemia.

METHODS

This expert review was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. These Best Practice Advice (BPA) statements were drawn from a review of the published literature and from expert opinion. Since systematic reviews were not performed, these BPA statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. BEST PRACTICE ADVICE 1: No single formulation of oral iron has any advantages over any other. Ferrous sulfate is preferred as the least expensive iron formulation. BEST PRACTICE ADVICE 2: Give oral iron once a day at most. Every-other-day iron dosing may be better tolerated for some patients with similar or equal rates of iron absorption as daily dosing. BEST PRACTICE ADVICE 3: Add vitamin C to oral iron supplementation to improve absorption. BEST PRACTICE ADVICE 4: Intravenous iron should be used if the patient does not tolerate oral iron, ferritin levels do not improve with a trial of oral iron, or the patient has a condition in which oral iron is not likely to be absorbed. BEST PRACTICE ADVICE 5: Intravenous iron formulations that can replace iron deficits with 1 or 2 infusions are preferred over those that require more than 2 infusions. BEST PRACTICE ADVICE 6: All intravenous iron formulations have similar risks; true anaphylaxis is very rare. The vast majority of reactions to intravenous iron are complement activation-related pseudo-allergy (infusion reactions) and should be treated as such. BEST PRACTICE ADVICE 7: Intravenous iron therapy should be used in individuals who have undergone bariatric procedures, particularly those that are likely to disrupt normal duodenal iron absorption, and have iron-deficiency anemia with no identifiable source of chronic gastrointestinal blood loss. BEST PRACTICE ADVICE 8: In individuals with inflammatory bowel disease and iron-deficiency anemia, clinicians first should determine whether iron-deficiency anemia is owing to inadequate intake or absorption, or loss of iron, typically from gastrointestinal bleeding. Active inflammation should be treated effectively to enhance iron absorption or reduce iron depletion. BEST PRACTICE ADVICE 9: Intravenous iron therapy should be given in individuals with inflammatory bowel disease, iron-deficiency anemia, and active inflammation with compromised absorption. BEST PRACTICE ADVICE 10: In individuals with portal hypertensive gastropathy and iron-deficiency anemia, oral iron supplements initially should be used to replenish iron stores. Intravenous iron therapy should be used in patients with ongoing bleeding who do not respond to oral iron therapy. BEST PRACTICE ADVICE 11: In individuals with portal hypertensive gastropathy and iron-deficiency anemia without another identified source of chronic blood loss, treatment of portal hypertension with nonselective β-blockers can be considered. BEST PRACTICE ADVICE 12: In individuals with iron-deficiency anemia secondary to gastric antral vascular ectasia who have an inadequate response to iron replacement, consider endoscopic therapy with endoscopic band ligation or thermal methods such as argon plasma coagulation. BEST PRACTICE ADVICE 13: In patients with iron-deficiency anemia and celiac disease, ensure adherence to a gluten-free diet to improve iron absorption. Consider oral iron supplementation based on the severity of iron deficiency and patient tolerance, followed by intravenous iron therapy if iron stores do not improve. BEST PRACTICE ADVICE 14: Deep enteroscopy performed in patients with iron-deficiency anemia suspected to have small-bowel bleeding angioectasias should be performed with a distal attachment to improve detection and facilitate treatment. Small-bowel angioectasias may be treated with ablative thermal therapies such as argon plasma coagulation or with mechanical methods such as hemostatic clips. BEST PRACTICE ADVICE 15: Endoscopic treatment of angioectasias should be accompanied with iron replacement. Medical therapy for small-bowel angioectasias should be reserved for compassionate treatment in refractory cases when iron replacement and endoscopic therapy are ineffective.

Diagnosis of Occult and Obscure Gastrointestinal Bleeding

Occult and obscure bleeding are challenging conditions to manage; however, recent advances in gastroenterology and endoscopy have improved our diagnostic and therapeutic capabilities. Obscure gastrointestinal (GI) bleeding is an umbrella category of bleeding of unknown origin that persists or recurs after endoscopic evaluation of the entire bowel fails to reveal a bleeding source. This review details the evaluation of patients with occult and obscure GI bleeding and offers diagnostic algorithms. The treatment of GI bleeding depends on the type and location of the bleeding lesion and an overview of how to manage these conditions is presented.

Role of Endoscopy in the Diagnosis, Grading, and Treatment of Portal Hypertensive Gastropathy and Gastric Antral Vascular Ectasia

Portal hypertensive gastropathy (PHG) and gastric antral vascular ectasia (GAVE) are 2 distinct gastric vascular abnormalities that may present with acute or chronic blood loss. PHG requires the presence of portal hypertension and is typically associated with chronic liver disease, whereas there is controversy about the association of GAVE with chronic liver disease and/or portal hypertension. Distinguishing between GAVE and PHG is crucial because their treatment strategies differ. This review highlights characteristic endoscopic appearances and the clinical features of PHG and GAVE, which, in turn, aid in their appropriate management.

Association between iron deficiency anemia and subsequent stomach and colorectal cancer diagnosis in Germany

PURPOSE

Iron deficiency anemia (IDA) is the most common form of anemia worldwide, resulting in a high burden of disease. Accumulating evidence suggests that IDA is associated with the development of gastrointestinal (GI) cancers.

METHODS

Data from the IDA database (IQVIA) of primary care practices in Germany of adult patients first diagnosed with IDA between January 2005 and December 2021 were retrospectively analyzed and compared with a 1:1 propensity score-adjusted cohort without IDA. Study outcomes were first stomach cancer or colorectal cancer (CRC) diagnosis up to 10 years after the index date as a function of IDA.

RESULTS

A total of 122,502 individuals with IDA and 122,502 individuals without IDA were included. The 10-year cumulative incidence of CRC was 1.4% in the IDA patients compared to 0.8% in the cohort without IDA (p < 0.001). Regression analysis revealed a significant association between IDA and subsequent CRC (HR 2.05; 95% CI 1.83-2.30). Stomach cancer was diagnosed in 0.3% of IDA patients compared to 0.2% in the non-IDA cohort during the 10-year follow-up period (p = 0.002). However, this was significant only in the age group > 80 years (HR 2.73; 95% CI 1.60-4.67) and in men (HR 1.90; 95% CI 1.38-2.61).

CONCLUSION

These findings add to the literature and suggest an association between IDA and GI cancers. The extent to which this association is due to GI bleeding or other pathophysiological processes that may be caused by IDA requires further investigation, particularly experimental studies.

The Diagnostic Accuracy of a Fecal Immunochemical Test in Detecting Colorectal Cancer and Advanced Precancerous Colorectal Neoplasia in Patients with Iron Deficiency: A Protocol for Systematic Review and Meta-Analysis

Background. Iron deficiency (ID) is a common micronutrient deficiency and the leading cause of anemia worldwide. ID can be caused by chronic occult blood loss from colorectal neoplasia including colorectal cancer (CRC) and advanced precancerous colorectal lesions. Current guidelines recommend colonoscopy in both men and postmenopausal women presenting with ID anemia (IDA). However, there is controversy on the investigation of patients presenting with a lower risk of CRC including younger women with ID and those with nonanemic ID (NAID). There is a need for a triaging tool to identify which ID patients may benefit from colonoscopy. The fecal immunochemical test (FIT) is sensitive for CRC screening in an asymptomatic population, but its role in ID patients is unclear. The aim of this study is to conduct a systematic review to determine the diagnostic accuracy of FIT for detecting CRC and advanced precancerous neoplasia in individuals presenting with ID with or without anemia. Methods and Analysis. This protocol conforms with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols and Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. A comprehensive search of the MEDLINE, Embase, and Web of Science databases will be undertaken for studies published after 2010 which involve patients with ID, who completed a FIT in the 6 months prior to colonoscopy, with FIT sensitivity and specificity calculated against the reference standard colonoscopy. The search will be limited to studies conducted after 2010 to reduce variability in colonoscopy quality. Risk of bias assessment will be conducted using the Quality Assessment of Diagnostic Accuracy Studies version 2. FIT sensitivity and specificity will be the primary measure of diagnostic accuracy, and data will be analysed using a random effects meta-analysis. Discussion. This review and meta-analysis will be the first to systematically explore the value of the FIT as a triaging tool for patients with ID. This trial is registered with CRD42022367162.

Real-world experience of intravenous iron sucrose supplementation and dynamics of soluble transferrin receptor and hepcidin in a Spanish cohort of absolute iron deficient patients

The study evaluated the safety and effectiveness of the generic intravenous (IV) iron treatment (Feriv®), in a Spanish cohort with absolute iron deficiency (ID) (serum ferritin <50 ng/ml, with or without anaemia) (n = 122; 91% women; median age of 44 years [IQR: 33.7-54]). Iron-related biomarkers were measured before treatment (baseline), 2 weeks after beginning the protocol (intermediate control, IC) and between 7 and 10 days after treatment completion (final time-point). Primary efficacy endpoints were ferritin levels ≥ 50 ng/ml, anaemia restoration or an increase in haemoglobin (Hb) of at least one point in patients without baseline anaemia. After treatment, iron-related biomarkers improved, including ferritin, Hb, sideremia, transferrin, transferrin saturation index, soluble transferrin receptor (sTfR), and hepcidin. Baseline ferritin concentration (13.5 ng/ml [IQR: 8-24.2]) increased at the IC and continued rising at the final time-point, reaching a median ferritin of 222 ng/ml and 97.3% of patients ≥ 50 ng/ml. At the final time-point, anaemia prevalence decreased from 26.2% to 5%, while the 34.1% without baseline anaemia showed an increase in Hb of at least one point. Headache was the only drug-adverse event recorded in 2.3% of patients. At a late time-point (27.5 median weeks after ending therapy [IQR: 22-40]), evaluated in a subgroup of 66 patients, 18% had ferritin levels < 50 ng/ml. Multivariate analysis showed that low baseline ferritin and high sTfR/hepcidin ratio tended to be independently associated with ID recurrence. Feriv® is a safe, effective first-line treatment for absolute ID, with improvement of serum ferritin and Hb. ID recurrence was associated with the baseline degree of iron stores depletion, indicated by serum ferritin, and sTfR/hepcidin ratio.

COVID-19 Pandemic Had Minimal Impact on Colonoscopy Completion After Colorectal Cancer Red Flag Sign or Symptoms in US Veterans

BACKGROUND

Delays in colonoscopy work-up for red flag signs or symptoms of colorectal cancer (CRC) during the COVID-19 pandemic are not well characterized.

AIMS

To examine colonoscopy uptake and time to colonoscopy after red flag diagnosis, before and during the COVID-19 pandemic.

METHODS

Cohort study of adults ages 50-75 with iron deficiency anemia (IDA), hematochezia, or abnormal stool blood test receiving Veterans Health Administration (VHA) care from April 2019 to December 2020. Index date was first red flag diagnosis date, categorized into "pre" (April-December 2019) and "intra" (April-December 2020) policy implementation prioritizing diagnostic procedures, allowing for a 3-month "washout" (January-March 2020) period. Outcomes were colonoscopy completion and time to colonoscopy pre- vs. intra-COVID-19, examined using multivariable Cox models with hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

There were 52,539 adults with red flag signs or symptoms (pre-COVID: 25,154; washout: 7527; intra-COVID: 19,858). Proportion completing colonoscopy was similar pre- vs. intra-COVID-19 (27.0% vs. 26.5%; p = 0.24). Median time to colonoscopy among colonoscopy completers was similar for pre- vs. intra-COVID-19 (46 vs. 42 days), but longer for individuals with IDA (60 vs. 49 days). There was no association between time period and colonoscopy completion (aHR: 0.99, 95% CI 0.95-1.03).

CONCLUSIONS

Colonoscopy work-up of CRC red flag signs and symptoms was not delayed within VHA during the COVID-19 pandemic, possibly due to VHA policies supporting prioritization and completion. Further work is needed to understand how COVID-19 policies on screening and surveillance impact CRC-related outcomes, and how to optimize colonoscopy completion after a red flag diagnosis.

Prediction of Gastrointestinal Tract Cancers Using Longitudinal Electronic Health Record Data

BACKGROUND

Luminal gastrointestinal (GI) tract cancers, including esophageal, gastric, small bowel, colorectal, and anal cancers, are often diagnosed at late stages. These tumors can cause gradual GI bleeding, which may be unrecognized but detectable by subtle laboratory changes. Our aim was to develop models to predict luminal GI tract cancers using laboratory studies and patient characteristics using logistic regression and random forest machine learning methods.

METHODS

The study was a single-center, retrospective cohort at an academic medical center, with enrollment between 2004-2013 and with follow-up until 2018, who had at least two complete blood counts (CBCs). The primary outcome was the diagnosis of GI tract cancer. Prediction models were developed using multivariable single timepoint logistic regression, longitudinal logistic regression, and random forest machine learning.

RESULTS

The cohort included 148,158 individuals, with 1025 GI tract cancers. For 3-year prediction of GI tract cancers, the longitudinal random forest model performed the best, with an area under the receiver operator curve (AuROC) of 0.750 (95% CI 0.729-0.771) and Brier score of 0.116, compared to the longitudinal logistic regression model, with an AuROC of 0.735 (95% CI 0.713-0.757) and Brier score of 0.205.

CONCLUSIONS

Prediction models incorporating longitudinal features of the CBC outperformed the single timepoint logistic regression models at 3-years, with a trend toward improved accuracy of prediction using a random forest machine learning model compared to a longitudinal logistic regression model.

Helicobacter pylori-Associated Iron Deficiency Anemia in Childhood and Adolescence-Pathogenesis and Clinical Management Strategy

Many epidemiological studies and meta-analyses show that persistent Helicobacter pylori infection in the gastric mucosa can lead to iron deficiency or iron deficiency anemia (IDA), particularly in certain populations of children and adolescents. Moreover, it has been demonstrated that H. pylori infection can lead to and be closely associated with recurrent and/or refractory iron deficiency and IDA. However, the pathogenesis and specific risk factors leading to this clinical outcome in H. pylori-infected children remain poorly understood. In general, most of pediatric patients with H. pylori-associated IDA do not show evidence of overt blood loss due to gastrointestinal hemorrhagic lesions. In adult populations, H. pylori atrophic gastritis is reported to cause impaired iron absorption due to impaired gastric acid secretion, which, subsequently, results in IDA. However, significant gastric atrophy, and the resultant substantial reduction in gastric acid secretion, has not been shown in H. pylori-infected children. Recently, it has been hypothesized that competition between H. pylori and humans for iron availability in the upper gastrointestinal tract could lead to IDA. Many genes, including those encoding major outer membrane proteins (OMPs), are known to be involved in iron-uptake mechanisms in H. pylori. Recent studies have been published that describe H. pylori virulence factors, including specific OMP genes that may be associated with the pathogenesis of IDA. Daily iron demand substantively increases in children as they begin pubertal development starting with the associated growth spurt, and this important physiological mechanism may play a synergistic role for the microorganisms as a host pathogenetic factor of IDA. Like in the most recent pediatric guidelines, a test-and-treat strategy in H. pylori infection should be considered, especially for children and adolescents in whom IDA is recurrent or refractory to iron supplementation and other definitive causes have not been identified. This review will focus on providing the evidence that supports a clear biological plausibility for H. pylori infection and iron deficiency, as well as IDA.

Iron deficiency and symptoms in women aged 20-49 years and relation to upper gastrointestinal and colon cancers

OBJECTIVE

Iron deficiency anaemia (IDA) in women aged 20-49 years may be caused by menses or gastrointestinal cancer. Data are sparse on the yield of endoscopy/colonoscopy in this population. Our aim was to determine the association of IDA and symptoms with cancers.

DESIGN

Retrospective cohort study within Kaiser Permanente Northern California. Participants were women aged 20-49 years tested for iron stores and anaemia during 1998, 2004 and 2010 and followed for 5 years for outcomes of oesophageal, gastric and colon cancers. Symptoms from the three prior years were grouped into dysphagia, upper gastrointestinal (UGI), lower gastrointestinal (LGI), rectal bleeding and weight loss.

RESULTS

Among 9783 anaemic women aged 20-49 years, there were no oesophageal, 6 gastric and 26 colon cancers. Incidences per 1000 for gastric cancer with and without iron deficiency (ID) were 0.60 (95% CI 0.23 to 1.55) and 0.63 (95% CI 0.17 to 2.31), and for colon cancer, 2.72 (95% CI 1.72 to 4.29) and 2.53 (95% CI 1.29 to 4.99). Endoscopies for UGI or dysphagia symptoms rather than bidirectional endoscopy for ID yielded more gastric cancers (n=5 and n=4, respectively) with fewer procedures (3793 instead of 6627). Colonoscopies for LGI or rectal bleed instead of for ID would detect more colon cancers (n=19 and n=18) with about 40% of the procedures (=2793/6627).

CONCLUSIONS

UGI and colon cancers were rare in women of menstruating age and when controlled for anaemia were as common without as with ID. Using symptoms rather than IDA as an indication for endoscopy found equal numbers of cancers with fewer procedures.

Small Bowel Malignancies in Patients Undergoing Capsule Endoscopy for Iron Deficiency Anemia

Small bowel malignancies are rare and usually asymptomatic or symptoms are nonspecific. Therefore, small bowel tumors are difficult to diagnose. In patients with iron deficiency anemia (IDA) who have negative bidirectional endoscopy results, the small bowel may be considered the source of bleeding. However, in asymptomatic IDA patients with negative bidirectional endoscopy results, evidence supporting the routine use of capsule endoscopy (CE) is insufficient. CE can be considered in selected patients with recurrent or persistent IDA. The frequency of small bowel malignancies is low in patients undergoing CE for IDA, but the usefulness of CE for the diagnosis of small bowel malignancies in younger age groups with IDA has been reported. For patients with risk factors for small bowel malignancy, investigation of the small bowel should be considered. Efforts should be made to prevent adverse events, such as capsule retention or capsule aspiration, through meticulous history taking and endoscopic capsule delivery as necessary.

British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults

Iron deficiency anaemia (IDA) is a major cause of morbidity and burden of disease worldwide. It can generally be diagnosed by blood testing and remedied by iron replacement therapy (IRT) using the oral or intravenous route. The many causes of iron deficiency include poor dietary intake and malabsorption of dietary iron, as well as a number of significant gastrointestinal (GI) pathologies. Because blood is iron-rich it can result from chronic blood loss, and this is a common mechanism underlying the development of IDA-for example, as a consequence of menstrual or GI blood loss.Approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the GI tract. Therefore optimal management of IDA requires IRT in combination with appropriate investigation to establish the underlying cause. Unexplained IDA in all at-risk individuals is an accepted indication for fast-track secondary care referral in the UK because GI malignancies can present in this way, often in the absence of specific symptoms. Bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract, though radiological scanning is an alternative in some situations for assessing the large bowel. In recurrent or refractory IDA, wireless capsule endoscopy plays an important role in assessment of the small bowel.IDA may present in primary care or across a range of specialties in secondary care, and because of this and the insidious nature of the condition it has not always been optimally managed despite the considerable burden of disease- with investigation sometimes being inappropriate, incorrectly timed or incomplete, and the role of IRT for symptom relief neglected. It is therefore important that contemporary guidelines for the management of IDA are available to all clinicians. This document is a revision of previous British Society of Gastroenterology guidelines, updated in the light of subsequent evidence and developments.

Iron Deficiency in Celiac Disease: Prevalence, Health Impact, and Clinical Management

Iron is an essential nutrient to life and is required for erythropoiesis, oxidative, metabolism, and enzymatic activities. It is a cofactor for mitochondrial respiratory chain enzymes, the citric acid cycle, and DNA synthesis, and it promotes the growth of immune system cells. Thus, iron deficiency (ID) leads to deleterious effects on the overall health of individuals, causing significant morbidity. Iron deficiency anemia (IDA) is the most recognized type of anemia in patients with celiac disease (CD) and may be present in over half of patients at the time of diagnosis. Folate and vitamin B12 malabsorption, nutritional deficiencies, inflammation, blood loss, development of refractory CD, and concomitant Heliobacter pylori infection are other causes of anemia in such patients. The decision to replenish iron stores and the route of administration (oral or intravenous) are controversial due, in part, to questions surrounding the optimal formulation and route of administration. This paper provides an algorithm based on the severity of symptoms; its impact on the health-related quality of life (HRQL); the tolerance and efficiency of oral iron; and other factors that predict a poor response to oral iron, such as the severity of histological damage, poor adherence to GFD, and blood loss due to mucosal lesions.

Overview of Helicobacter pylori Infection: Clinical Features, Treatment, and Nutritional Aspects

Helicobacter pylori (H. pylori) is a 0.5-1 µm wide, 2-4 µm long, short helical, S-shaped Gram-negative microorganism. It is mostly found in the pyloric region of the stomach and causes chronic gastric infection. It is estimated that these bacteria infect more than half of the world's population. The mode of transmission and infection of H. pylori is still not known exactly, but the faecal-oral and oral-oral routes via water or food consumption are thought to be a very common cause. In the last three decades, research interest has increased regarding the pathogenicity, microbial activity, genetic predisposition, and clinical treatments to understand the severity of gastric atrophy and gastric cancer caused by H. pylori. Studies have suggested a relationship between H. pylori infection and malabsorption of essential micronutrients, and noted that H. pylori infection may affect the prevalence of malnutrition in some risk groups. On the other hand, dietary factors may play a considerably important role in H. pylori infection, and it has been reported that an adequate and balanced diet, especially high fruit and vegetable consumption and low processed salty food consumption, has a protective effect against the outcomes of H. pylori infection. The present review provides an overview of all aspects of H. pylori infection, such as clinical features, treatment, and nutrition.

Threshold ferritin and hepcidin concentrations indicating early iron deficiency in young women based on upregulation of iron absorption

BACKGROUND

Plasma ferritin is a widely used indicator to detect iron deficiency, but the threshold ferritin that defines iron deficiency remains uncertain. Our aim was to define the ferritin concentration at which the body begins to upregulate iron absorption from the diet; this could provide a functionally-defined threshold of incipient iron deficiency. We hypothesized this threshold ferritin concentration would correspond to the threshold hepcidin concentration at which iron absorption begins to increase.

METHODS

We performed a pooled analysis of our stable iron isotope studies (n = 1058) conducted from 2006 to 2019 in healthy women (age 18-50 years; mean±SD ferritin 33.7 ± 27.1 μg/L) that measured iron absorption from labeled test meals providing physiological amounts of iron. To fit relationships between iron absorption, ferritin and hepcidin, we used generalized additive modeling, and to identify thresholds, we estimated the first derivatives of the fitted trend to assess inflection points in these relationships.

FINDINGS

Hepcidin increased linearly with increasing ferritin over the entire range of ferritin values. Iron absorption began to increase below a threshold hepcidin value of 3.09 (95%CI: 2.80, 3.38) nmol/l, above which iron absorption remained stable. Iron absorption began to increase below a threshold ferritin value of 51.1 (95%CI: 49.1, 53.1) µg/l, above which iron absorption remained stable. The latter two findings were internally consistent in that, in the relationship between hepcidin and ferritin, a hepcidin of ~3 nmol/l corresponded to a ferritin of ~51 µg/l.

INTERPRETATION

Based on physiological upregulation of iron absorption, a threshold ferritin of <50 µg/L, corresponding to a threshold hepcidin of <3 nmol/l, indicates incipient iron deficiency in young women.

The Value of Quantitative Faecal Immunochemical Testing as a Prioritisation Tool for the Endoscopic Investigation of Patients With Iron Deficiency

Difficulty in providing endoscopy for patients with iron deficiency anaemia (IDA) during the COVID-19 pandemic has highlighted the requirement for a prioritisation tool. We aimed to test the validity of qFIT as a prioritisation tool in patients with iron deficiency and its ability to identify patients with advanced neoplastic lesions (ANLs). Data collected from patients referred with biochemically proven iron deficiency (ferritin ≤ 15 μg/L) and synchronous qFIT who underwent full gastrointestinal investigation within NHS Greater Glasgow and Clyde was analysed retrospectively. Patients who did not undergo full investigation, defined as gastroscopy and colonoscopy or CT colonography, were excluded. ANLs were defined as defined as upper GI cancer, colorectal adenoma ≥ 1 cm or colorectal cancer. Area under the curve (AUC) analysis was performed on qFIT results and outcome, defined as the presence of an ANL. AUC analysis guided cut-off scores for qFIT. Patients with a qFIT of <10, 10-200, >200, were allocated a score of 1, 2, and 3, respectively. A total of 575 patients met criteria for inclusion into the study. Overall, qFIT results strongly predicted the presence of ANLs (AUC 0.87, CI 0.81-0.92; P < 0.001). The prevalence of ANLs in patients with scores 1-3 was 1.2, 13.5, and 38.9% respectfully. When controlled for other significant variables, patients with a higher qFIT score were statistically more likely to have an ANL (qFIT score = 2; OR 12.8; P < 0.001, qFIT score = 3, OR 50.0; P < 0.001). A negative qFIT had a high NPV for the presence of ANLs (98.8%, CI 97.0-99.5%). These results strongly suggest that qFIT has validity as a prioritisation tool in patients with iron deficiency; both allowing for a more informed decision of investigation of patients with very low risk of malignancy, and in identifying higher risk patients who may benefit from more urgent endoscopy.

Leptin and Obesity: Role and Clinical Implication

The peptide hormone leptin regulates food intake, body mass, and reproductive function and plays a role in fetal growth, proinflammatory immune responses, angiogenesis and lipolysis. Leptin is a product of the obese (ob) gene and, following synthesis and secretion from fat cells in white adipose tissue, binds to and activates its cognate receptor, the leptin receptor (LEP-R). LEP-R distribution facilitates leptin's pleiotropic effects, playing a crucial role in regulating body mass via a negative feedback mechanism between adipose tissue and the hypothalamus. Leptin resistance is characterized by reduced satiety, over-consumption of nutrients, and increased total body mass. Often this leads to obesity, which reduces the effectiveness of using exogenous leptin as a therapeutic agent. Thus, combining leptin therapies with leptin sensitizers may help overcome such resistance and, consequently, obesity. This review examines recent data obtained from human and animal studies related to leptin, its role in obesity, and its usefulness in obesity treatment.

Anemia as a Problem: GEH Approach

BACKGROUND

Anemia is present in almost 5% of adults worldwide and accompanies clinical findings in many diseases. Diseases of the gastrointestinal (GI) tract and liver are a common cause of anemia, so patients with anemia are often referred to a gastroenterologist.

SUMMARY

Anemia could be caused by various factors such as chronic bleeding, malabsorption, or chronic inflammation. In clinical practice, iron deficiency anemia and the combined forms of anemia due to different pathophysiological mechanisms are most common. Esophagogastroduodenoscopy, colonoscopy, and the small intestine examinations in specific situations play a crucial role in diagnosing anemia. In anemic, GI asymptomatic patients, there are recommendations for bidirectional endoscopy. Although GI malignancies are the most common cause of chronic bleeding, all conditions leading to blood loss, malabsorption, and chronic inflammation should be considered. From a gastroenterologist's perspective, the clinical spectrum of anemia is vast because many different digestive tract diseases lead to bleeding. Key Messages: The gastroenterological approach in solving anemia's problem requires an optimal strategy, consideration of the accompanying clinical signs, and the fastest possible diagnosis. Although patients with symptoms of anemia are often referred to gastroenterologists, the diagnostic approach requires further improvement in everyday clinical practice.

Iron deficiency: a modern primer to diagnosis and management

PURPOSE OF REVIEW

Iron deficiency with anemia (IDA) and without anemia remain a diagnostic and management challenge. Iron deficiency has a broad spectrum of causes, including gastrointestinal malignancy. The purpose of this review is to summarize the value and limitations of current methods to diagnose iron deficiency and underline the relevance of contemporaneous evidence to guide the pretest probability of gastrointestinal disease.

RECENT FINDINGS

A number of biomarkers for iron deficiency exist, and all have their caveats. Serum ferritin remains the most pragmatic means of diagnosing iron deficiency. Hepcidin holds future promise as a marker of iron status during inflammatory states. Men and postmenopausal women with IDA have the highest overall prevalence of gastrointestinal malignancy (∼11%), while premenopausal women with IDA (<1.5%) and those with iron deficiency without anemia (<0.5%) have a very low risk. Noninvasive investigation with fecal immunochemical test and fecal calprotectin hold promise to guide further investigations in lower risk groups.

SUMMARY

Confirmation of iron deficiency remains a challenge. Appropriate risk stratification is the key to guiding judicious gastrointestinal investigation. Use of noninvasive tests may play an important role in lower risk groups. Risk prediction tools applicable to relevant populations are required.