Half of IBD Patients Without Anemia Have Iron Deficiency Leading to Similar Rates of Fatigue as Iron Deficiency Anemia

Introduction: Inflammatory bowel disease (IBD) patients are at high risk for iron deficiency anemia due to chronic intestinal inflammation, malabsorption and dietary restrictions. Iron deficiency alone develops prior to anemia, although little is known about the prevalence, clinical significance and management of non-anemic iron deficiency. Our aim was to describe the prevalence and clinical manifestations of non-anemic iron deficiency. Methods: Adult IBD patients with available laboratory data including iron studies were included. Patient demographics, disease phenotype, medications, laboratory data for iron deficiency and presence of fatigue were abstracted from the medical records. Iron deficiency was defined as a ferritin < 30 ug/L in the absence of inflammation (normal C-reactive protein [CRP]) or ferritin < 100 in the presence of inflammation (elevated CRP), according to European Crohn's and Colitis Organization guidelines. Anemia was determined based on the study center's laboratory references: hemoglobin levels < 13.9 g/dL for men and < 12.0 g/dL for women. The presence and degree of fatigue was documented at each office visit. Laboratory data within 30 days of the office visit was used. Results: Of 116 IBD patients, 47 patients (41%) had iron deficiency anemia, whereas 28 patients (24%) had non-anemic iron deficiency. Of the 63 IBD patients with anemia, 47 (74%) had iron deficiency anemia. Of the 53 IBD patients without anemia, 28 (53%) had iron deficiency. Patients with non-anemic iron deficiency were more likely to have ulcerative colitis whereas iron deficiency anemia patients were more likely to have Crohn's disease (p < 0.05). The presence of fatigue in patients with non-anemic iron deficiency was similar to those with iron deficiency anemia (75% vs. 70%; p = 0.79). Severe fatigue was seen in 36% of patients with non-anemic iron deficiency compared to 40% of patients with iron deficiency anemia, p = 0.81. Conclusion: Iron deficiency is found in half of IBD patients without anemia and a quarter of all IBD patients. Non-anemic iron deficiency is associated with a similar level of fatigue as iron deficiency anemia. Therefore, clinicians should consider screening for and treating iron deficiency even in the absence of anemia in IBD patients with symptoms of fatigue.