Anemia is a significant problem in elderly patients. Although many anemic elderly patients can be diagnosed with nutritional deficiency, anemia of chronic inflammation or comorbid diseases that explain their decreased hematocrit, the etiology of anemia in a significant fraction remains obscure. There is evidence to suggest that the hematopoietic stem cell displays increasing erythropoietin (EPO) resistance with age. EPO levels rise in elderly, nonanemic patients, and it is hypothesized that there is an interplay between this rising demand for EPO and the decreasing ability of the aging kidney to produce adequate hormone to meet that need. There is further considerable evidence that aging is associated with increased proinflammatory cytokine expression and that many of these cytokines can contribute to EPO insensitivity. Consequently, genetic variation in the expression of these proinflammatory cytokines may influence the development of anemia in elderly patients, both through induction of hepcidin expression (anemia of inflammation) and through cytokine suppression of erythroid colony formation. The impact of inflammatory mediators, EPO insensitivity, and other factors that may act on the hematopoietic stem cell to decrease erythropoiesis are under active study and should serve to elucidate the pathophysiology of this important cause of morbidity and mortality in elderly individuals. A better understanding of the pathophysiology of anemia in elderly patients should provide critical entry points for interventions that will improve survival and quality of life in the aging population.Anemia of any degree is recognized as a significant independent contributor to morbidity, mortality, and frailty in elderly patients. 1,2 Although anemia has often been considered a normal consequence of aging, the pathophysiology of such an age-related decline in erythrocyte production is obscure, and efforts to understand anemia in elderly individuals have become a major target of research interest. Recent studies suggest that, although anemia likely arises in part from the cumulative effect of age-related comorbidities and physical decline, there are still age-specific changes in the hematopoietic system that influence red blood cell production. Understanding of these changes could have important diagnostic and therapeutic implications for addressing this common problem. Because the number of elderly individuals is expected to reach unprecedented levels in the 21 st century, anemia represents an emerging global health problem negatively impacting quality of life in a significant proportion of the elderly population and requiring an ever-greater allocation of health care resources.
Epidemiology of Anemia in Elderly PatientsIn the Third National Health and Nutrition Examination Survey (NHANES III) study, the incidence of anemia in men and women older than age 65 was 11% and 10%, respectively. 3 The prevalence of anemia rose rapidly after the age of 50, approaching a rate greater than 20% in those individuals aged 85 years or older. I...