Anemia is a reduction in the blood’s capacity to transport oxygen, typically measured as a low level of hemoglobin or a reduced red blood cell count. Anemia is a common finding in older men, with prevalence estimates often ranging from 10% to 20% in the general elderly population and significantly higher in hospitalized or nursing home residents. The World Health Organization defines anemia in men as a hemoglobin level below 130 grams per liter (g/L).
Anemia from Nutritional Deficiencies
Inadequate intake, poor absorption, or inefficient utilization of specific nutrients can directly impair the bone marrow’s ability to produce healthy red blood cells. Iron deficiency anemia is the most common nutritional cause and results in microcytic anemia, characterized by red blood cells that are smaller than normal and pale in color due to insufficient hemoglobin content. While iron deficiency is often linked to blood loss, it can also stem from age-related factors like reduced stomach acid production, which is necessary for iron absorption.
A deficiency in Vitamin B12 or folate leads to megaloblastic anemia, where red blood cells are abnormally large. Vitamin B12 deficiency is frequently caused by pernicious anemia, an autoimmune condition that prevents the body from producing intrinsic factor, a protein required for B12 absorption. Reduced stomach acid, common with advancing age or medication use, also hinders the release of B12 from food proteins. Folate deficiency, although less common, also impairs DNA synthesis, resulting in the production of large, immature red blood cells.
Anemia Due to Occult Blood Loss
Occult blood loss is a major cause of iron deficiency anemia in elderly men. The gastrointestinal (GI) tract is the most frequent source of this chronic, low-grade blood loss. This slow, continuous bleeding depletes the body’s iron stores over time, leading to iron deficiency anemia.
Common sources of occult GI bleeding include benign conditions like peptic ulcers and diverticulosis. Angiodysplasia is another significant cause that becomes more common with age. Of greatest concern is colorectal cancer, which can cause subtle, chronic bleeding before more obvious symptoms appear. Unexplained iron deficiency anemia in an elderly male is often presumed to be a result of GI blood loss until a thorough investigation, typically involving endoscopy and colonoscopy, proves otherwise.
Anemia of Chronic Disease and Inflammation
Anemia of Chronic Disease (ACD), also known as Anemia of Inflammation, is one of the most common forms of anemia in older adults. Chronic infections, autoimmune disorders like rheumatoid arthritis, and heart failure trigger a sustained inflammatory response in the body. This response involves the release of inflammatory signaling molecules, such as cytokines, which disrupt the normal regulation of iron metabolism.
The inflammatory state promotes the production of hepcidin, a hormone that effectively traps iron within storage cells and reduces its absorption from the gut. This mechanism prevents the iron from being available to the bone marrow for red blood cell production, creating a state of “functional iron deficiency” even if the body has sufficient iron stores. Chronic Kidney Disease (CKD) is a particularly potent cause of ACD because the kidneys are the primary site for producing erythropoietin (EPO). As kidney function declines, the production of EPO falls to low levels, directly impairing the bone marrow’s ability to generate red blood cells.
Hematologic Causes
In some cases, the cause of anemia lies directly within the bone marrow. Myelodysplastic Syndromes (MDS) are a group of disorders characterized by the bone marrow producing abnormal, poorly formed, or defective blood cells. MDS is strongly associated with advancing age, typically affecting men over 60.
The defective blood cells often die prematurely, resulting in low counts of red blood cells, white blood cells, and platelets. MDS is considered a type of cancer and carries a risk of progression to acute myeloid leukemia. Aplastic Anemia is another, though less common, condition where the bone marrow stem cells are damaged or destroyed, leading to a severe reduction in the number of all blood cells produced.