A comprehensive evaluation of the gastrointestinal tract in iron-deficiency anemia with predefined hemoglobin below 9mg/dL: A prospective cohort study.

BACKGROUND:Anemia is defined as hemoglobin below the cutoff of normal in studies examining the gastrointestinal (GI) tract in iron-deficiency anemia (IDA). Although the risk of GI cancer (GIC) increases as hemoglobin decreases, guidelines do not usually recommend hemoglobin thresholds for IDA investigation. METHODS:To elucidate whether underlying GI disorders explain the different hemoglobin values and clinical outcomes observed initially in IDA patients referred for GI workup, we prospectively investigated the diagnostic yield of a thorough GI examination in consecutive IDA adults with predefined hemoglobin <9g/dL and no extraintestinal bleeding. RESULTS:4552 patients were enrolled over 10 years. 96% of 4038 GI lesions were consistent with occult bleeding disorders and 4% with non-bleeding disorders. Predominant bleeding disorders included upper GI ulcerative/erosive lesions (51%), GIC (15%), and angiodysplasias (12%). Diffuse angiodysplasias (45% of angiodysplasias) and GIC showed the lowest hemoglobin values (6.3 [1.5] and 6.4 [1.3]g/dL, respectively). While the spread (diffuse vs. localized) and number (<3 vs. ≥3) of angiodysplasias correlated with the degree of anemia, hemoglobin values were lower in GIC with vs. without ulcerated/friable lesions (6.0 [1.1] vs. 7.0 [1.2]g/dL, P<0.001). CONCLUSION:Not only GIC but also diffuse angiodysplasias caused the most severe anemia in IDA with predefined hemoglobin values <9g/dL.