Serum erythropoietin titers in the aged

Erythropoietin (Epo) titers in the aged (from 70 to 89 years) were determined by a radioimmunoassay. Epo levels in normal elderly subjects were not different from levels in the young volunteers. The serum Epo levels in elderly patients with anemia were inversely related to hemoglobin levels; their regression coefficient was not worse than that found in young patients. It is suggested that the reactivity of Epo production to anemia in the aged may not be worse than that reactivity in the young.