The Natural History of Iron Deficiency Anemia

Current evidence suggests that adult men and nonmenstruating women with iron deficiency anemia (IDA) should undergo gastrointestinal (GI) evaluation to detect a potential bleeding lesion. We hypothesized that after endoscopic evaluation and treatment, IDA would be expected to resolve. Thus, we aimed to understand the natural history of IDA, in particular long-term outcomes.

Adult patients with IDA (defined as anemia and ferritin <50 ng/mL) who were diagnosed between 2004 and 2008 and who underwent endoscopic evaluation as part of their diagnostic work-up for IDA were included. Patients were subsequently followed up for at least 5 years.

A total of 93 patients were included, with a mean follow-up of 6 years. A lesion (either an upper or lower GI) consistent with chronic blood loss and IDA was identified in 54 patients (58%). Overall, only 14 patients with endoscopic lesions and 16 patients without endoscopic lesions, totaling 30/93 (33%) of all patients, had complete resolution of their anemia. In the 63/93 (67%) who remained anemic after medical management, 33 underwent repeat endoscopy(ies), which identified 7 new lesions (7 different patients), all in the upper GI tract. Among the patients who remained anemic after initial evaluation, no new GI malignancies were identified during follow-up.

Many patients with IDA, with or without GI tract lesions thought to be responsible for their IDA, remain anemic despite adequate therapy during long-term follow-up. In this study, after appropriate initial GI evaluation, even in those patients with persistent IDA, new GI malignancies were not identified.