What are the common causes and treatment options for anemia in an elderly female patient with potential chronic diseases such as kidney disease, diabetes, or gastrointestinal disorders?

Causes of Anemia in an Elderly Female

Iron deficiency is the most common contributory factor in approximately half of anemia cases in elderly women, though the etiology is typically multifactorial involving poor diet, reduced iron absorption, occult blood loss, medications (especially aspirin and NSAIDs), and chronic diseases such as chronic kidney disease and chronic heart failure. 1

Primary Etiologic Categories

Iron Deficiency Anemia (Most Common)

• Iron deficiency contributes to approximately 50% of anemia cases in elderly patients, often coexisting with vitamin B12 and/or folate deficiencies 1
• Multiple mechanisms operate simultaneously in elderly women: 1
  • Poor dietary iron intake due to limited access to iron-rich foods or poor dentition 1
  • Reduced iron absorption from age-related gastric achlorhydria 1
  • Occult gastrointestinal blood loss from mucosal lesions, angiodysplasia, or malignancy 1
  • Medication-induced blood loss, particularly from aspirin, NSAIDs, and anticoagulants/antiplatelet agents 1
• Gastrointestinal malignancy must be excluded, as colorectal and gastric cancers frequently present with iron deficiency anemia in this population 1
• Dual pathology (disease in both upper and lower GI tract) occurs in 1-10% of cases and is particularly common in elderly patients 1

Chronic Kidney Disease

• CKD is a major cause of anemia when glomerular filtration rate falls below 60 mL/min/1.73m², with prevalence increasing substantially when GFR drops below 30 mL/min/1.73m² 1
• The pathogenesis is multifactorial: 1
  • Inadequate erythropoietin production by failing kidneys 2
  • Functional iron deficiency (iron trapped in storage, unavailable for erythropoiesis) 1
  • Reduced iron absorption and increased blood loss 1
  • Hemolysis and other mechanisms 1
• Functional iron deficiency in CKD is defined as transferrin saturation ≤20% with ferritin ≤100 μg/L in predialysis patients or ≤200 μg/L in hemodialysis patients 1

Chronic Inflammatory Conditions

• Inflammation was identified as a cause in 62.1% of hospitalized elderly anemic patients, making it the single most common finding 3, 4
• Chronic inflammation leads to functional iron deficiency through increased hepcidin release, which reduces iron absorption and mobilization 1
• Hemoglobin correlates inversely with C-reactive protein levels (r=-0.296) 4
• Common inflammatory sources include chronic infections, autoimmune diseases, and malignancies 3, 4

Nutritional Deficiencies Beyond Iron

• Folate deficiency occurs in 6.7-21% of elderly anemic patients 3, 4
• Vitamin B12 (cobalamin) deficiency occurs in 11.6% of cases 3
• These deficiencies frequently coexist with iron deficiency 1
• Macrocytosis is present in only 7.4% of patients with folate/B12 deficiency, making mean corpuscular volume an unreliable screening tool 3

Chronic Heart Failure

• Iron deficiency is found in 40-70% of patients with chronic heart failure, defined as ferritin <100 μg/L and/or transferrin saturation <20% 1
• Contributing mechanisms include malabsorption, malnutrition, GI blood loss (exacerbated by anticoagulants), and chronic inflammation with elevated hepcidin 1

Myelodysplastic Syndrome

• Myelodysplastic syndromes should be suspected in elderly patients with unexplained anemia, particularly when accompanied by: 4
  • Thrombocytopenia (present in 5.4% of anemic elderly) 4
  • Leukopenia (present in 8.26% of anemic elderly) 4
  • Macrocytic alterations (present in 18.4% of anemic elderly) 4
• This diagnosis is often missed initially and requires bone marrow evaluation 5, 4

Diagnostic Approach Algorithm

Initial Laboratory Assessment

• Confirm anemia: hemoglobin <12 g/dL in postmenopausal women 6, 2
• Confirm iron deficiency: serum ferritin <45 ng/mL is the single most useful marker, though ferritin can be falsely elevated in inflammatory conditions 6
• Measure transferrin saturation and total iron binding capacity 6
• Check renal function (serum creatinine and estimated GFR) 1, 2
• Obtain inflammatory markers (C-reactive protein, erythrocyte sedimentation rate) 3, 4
• Screen for vitamin B12 and folate deficiency 1, 3

Celiac Disease Screening

• Perform tissue transglutaminase antibody (IgA type) with total IgA level in all cases of unexplained iron deficiency anemia, as celiac disease accounts for 3-5% of cases 6, 7

Gastrointestinal Investigation

• Evaluation of both upper and lower GI tract should be considered when iron deficiency anemia is confirmed, given the high prevalence of malignancy and dual pathology in elderly patients 1
• CT colonography may be a more appropriate alternative to colonoscopy for frail elderly patients with significant comorbidities 1
• The risks and benefits of invasive endoscopic investigation must be carefully weighed in patients with major comorbidities, limited performance status, or reduced life expectancy 1
• Upper endoscopy with duodenal biopsies if celiac serology is positive 6

Medication Review

• Explicitly document all NSAID use (including over-the-counter ibuprofen, naproxen, aspirin), anticoagulants, and antiplatelet agents, as patients often fail to report over-the-counter medications 6, 7

Critical Pitfalls to Avoid

• Do not rely on mean corpuscular volume for diagnostic classification, as microcytosis is present in only 27.5% of iron-deficient patients and macrocytosis in only 7.4% of B12/folate-deficient patients 3, 4
• Do not assume a single cause has been identified and stop investigating, as 46.3% of elderly anemic patients have multifactorial etiologies 3
• Do not interpret ferritin in isolation when inflammatory conditions are present, as ferritin is an acute phase reactant and may be falsely elevated 1, 6
• Do not accept minor GI findings as the sole explanation without completing full upper and lower tract evaluation, given the 1-10% rate of dual pathology 1
• Do not overlook functional iron deficiency in patients with chronic kidney disease or heart failure, as standard iron parameters require different interpretation in these populations 1

Treatment Considerations

Iron Replacement

• Oral iron administration remains standard first-line treatment in most elderly patients 1
• Parenteral iron is a convenient and relatively safe alternative when oral iron is not tolerated, in cases of malabsorption, or with ongoing blood loss 1, 8
• Continue iron therapy for 2-3 months after hemoglobin normalizes to adequately replenish iron stores 8

Disease-Specific Management

• CKD-related anemia requires consultation with nephrology for consideration of erythropoiesis-stimulating agents and intravenous iron, particularly when GFR <30 mL/min/1.73m² 1, 2
• Vitamin B12 deficiency requires intramuscular administration of 100 mcg daily for 6-7 days, then alternate days for seven doses, then every 3-4 days for 2-3 weeks, followed by 100 mcg monthly for life 9