Unexplained Anemia Predominates Despite an Intensive Evaluation in a Racially Diverse Cohort of Older Adults From a Referral Anemia Clinic

BACKGROUND: To accurately determine the causes of anemia and proportion of unexplained anemia in a racially diverse cohort of older adults after a comprehensive and standardized evaluation. METHODS: We evaluated results from a single-institutional university anemia clinic. Patients with anemia, defined as a hemoglobin less than 13.0 g/dL for men and less than 12.0 g/dL for women, underwent a prospective standardized history, physical examination, and laboratory measures, with additional studies including bone marrow examination as indicated. Empiric treatment trials were given for identified deficiencies. RESULTS: One hundred and seventy-four primarily community-dwelling adults aged 65 years and older were evaluable. African Americans accounted for 69% of patients and whites were 27%. Anemia etiologies included iron deficiency anemia at 25.3%, anemia of chronic inflammation at 9.8%, and hematologic malignancy in 7.5%. Unexplained anemia in the elderly accounted for 43.7% and predominated in both African Americans and whites. The prevalence of iron deficiency anemia and hematologic malignancies did not differ by race. Unexplained anemia in the elderly showed a consistent phenotype composed of a hypoproliferative mild-to-moderate anemia with suppressed serum erythropoietin. Specifically, erythropoietin levels showed no correlation with hemoglobin concentration in unexplained anemia in the elderly (r = -.15, p = .19) as opposed to iron deficiency anemia (r = -.63, p < .0001). CONCLUSIONS: In summary, an intensive hematologic evaluation reveals a wide number of anemia etiologies among older adults, including 7.5% with hematologic malignancies; nevertheless, unexplained anemia in the elderly prevails as the most common category in whites and African Americans.