Anemia is the most common hematologic abnormality in older adults. Overall prevalence of anemia in community-dwelling older adults ranges from 10% to 24%. The prevalence in long-term care or hospitalized older adults is close to 40%. The age distribution of anemia is shown in Figure 52–1. Race appears to also influence hemoglobin levels. In the longitudinal National Health and Nutrition Examination Survey (NHANES) III, the prevalence of anemia was found to be three times higher in non-Hispanic blacks compared with non-Hispanic whites. Anemia is recognized as a contributor to increased morbidity and mortality, and therefore, it is important to properly diagnose and treat anemia.
Age distribution of anemia. (A) Hemoglobin values by age. (B) Prevalence (%) of anemia by age. (C) Prevalence (%) of severe anemia (hemoglobin <10 g/dL) by age. (Data from Bach V, Schruckmayer G, Sam I, Kemmler G, Stauder R. Prevalence and possible causes of anemia in the elderly: a cross-sectional analysis of a large European university hospital cohort, Clin Interv Aging 2014 Jul 22;9:1187-96.)
The NHANES III study revealed that there are three broad categories of anemia in older adults: one-third of cases are secondary to nutritional deficiencies (iron, folic acid, or vitamin B12); one-third are secondary to inflammation; and one-third are unexplained. Unexplained anemia is commonly multifactorial and includes bone marrow failure and nutritional and inflammatory syndromes. There has been extensive literature and research on the increased proinflammatory cytokines and impact on bone marrow function (defined as inflammaging), as well as literature on the gradual degradation of the immune system, called immunosenescence.
Similar to younger patients, anemia in older adults is most commonly defined according to the 1968 World Health Organization criteria of a hemoglobin (Hgb) <13 g/dL in men and <12 g/dL in women.
SYMPTOMS OF ANEMIA IN OLDER ADULTS
Clinical symptoms of anemia are dependent on the severity and acuity of the anemia and the patient’s oxygen demand. Symptomatic anemia typically reflects impaired oxygen delivery to tissues as a consequence of decreased Hgb concentration. This may lead to increased cardiac output states and increased tissue hypoxia and progressive decline in organ function. In general, anemia that develops slowly over time tends to present with fewer symptoms than acute-onset anemia, regardless of the underlying etiology. As in younger adults, rapidly developing anemia may additionally cause symptoms because of the effects of hypovolemia. Such symptomatic illness may be more profound and poorly tolerated in older adults because of increased frailty and decreased performance status often related to the presence of multiple chronic ...