Effect of Age on Hematopoiesis in Man

We have shown previously that the cause of anemia in healthy elderly subjects can usually not be identified. In this study. hematopoiesis was examined in 1 8 healthy elderly subjects with unexplained anemia and in 1 5 young and 15 healthy elderly individuals without anemia. No reduction in circulating testosterone was noted, making decreased androgen levels as a cause for the anemia unlikely. The 2,3 diphospho-glycerate (2.3DPG) levels in the anemic subjects were significantly higher than their corresponding controls, suggesting that the anemia was pathologic. as no increase would be expected if the low hemoglobin was a physiologic adjustment to age. The anemia was associated with a reduction in marrow normoblast and CFU-E number. L ITTLE INFORMATION is available regarding the effects of aging on bone marrow function. One area that has been extensively investigated has been anemia. Large epidemiologic studies in the United States and Canada indicate that anemia in females above age 59 is approximately equal to that found in females of child-bearing age. In men, a definite increase in the older age group is found.’3 Studies from Great Britain are important, as they have determined the incidence of anemia in large numbers of subjects over age 60. In both males and females, the incidence of anemia increases significantly with each successive decade.46 Anemia is not thought to be a normal feature of aging, as the etiologies in the elderly are very similar to those in young subjects. Thus, iron deficiency and the anemia of chronic disease are quoted as the two most frequent diagnoses.7 Recently, however, a careful evaluation of healthy elderly living at home showed that iron deficiency anemia is much rarer in elderly than in young females and accounts for only a small fraction of anemia in elderly males.8 We have recently demonstrated a high incidence of anemia in a group of carefully selected healthy elderly subjects living in the Little Rock, AR, area. We confirmed that iron deficiency anemia was rare and found that the anemia ofchronic disease, folate deficiency, hemolysis, and other rarer causes of anemia were uncommon. The