Abstract
We evaluated the relationship between erythropoietin (EPO) and hemoglobin (Hb) concentrations in 156 normal subjects ranging from 60 to 98 years old. EPO was determined by a radioimmunoassay. The serum EPO concentration in subjects with Hb concentrations greater than 12.0 g/dl (26.9 ± 15.2 mU/ml), was significantly higher than that in younger controls (15.8 ± 5.0 mU/ml, p < 0.001). No sex difference in serum EPO level was detected. In addition, there was an inverse semilogarithmic relationship between EPO and Hb concentrations in subjects with Hb concentrations less than 12.0 g/dl (r = ––0.559, p < 0.001). EPO concentrations in the elderly were lower than those in young subjects with iron deficiency anemia with the same Hb level. Thus, in the elderly, a high EPO concentration may be preventing a decrease in the Hb concentration. However, a decreased EPO response to low Hb concentrations may be a contributing factor in anemia in the elderly.