What are the causes of low ferritin levels in menopausal women?

Causes of Low Ferritin in Menopausal Women

The most common causes of low ferritin in menopausal women are gastrointestinal blood loss, malabsorption, and occult gastrointestinal malignancy, which require thorough gastrointestinal evaluation including both upper and lower endoscopy. 1

Primary Causes of Low Ferritin in Menopausal Women

Gastrointestinal Causes

• Occult GI blood loss:

  • Colonic cancer/polyps
  • Gastric cancer
  • Peptic ulcer disease
  • Angiodysplasia
  • Gastric antral vascular ectasia (GAVE)
  • Portal hypertensive gastropathy
  • Small bowel angioectasias 1

• Malabsorption:

  • Celiac disease (found in 3-5% of iron deficiency anemia cases) 1
  • Previous gastrectomy 1
  • H. pylori infection (impairs iron absorption) 1

Medication-Related Causes

• NSAID use (causing GI mucosal damage and bleeding) 1
• Antiplatelet or anticoagulant therapy (increasing risk of GI bleeding) 1

Other Medical Conditions

• Chronic inflammatory conditions (can affect iron metabolism) 1
• Chronic kidney disease (affecting erythropoiesis) 1
• Chronic periodontitis (associated with elevated ferritin as an acute phase reactant) 2

Lifestyle and Physiological Factors

• Poor dietary iron intake 1
• Low alcohol intake (moderate alcohol consumption is associated with higher ferritin levels in postmenopausal women) 3
• Physical activity (inversely related to ferritin levels) 3

Diagnostic Approach for Low Ferritin in Menopausal Women

1. Define iron deficiency:

   • Ferritin <45 μg/L is considered diagnostic of iron deficiency 1
   • In inflammatory conditions, ferritin may be falsely elevated; values <100 μg/L may still indicate iron deficiency 1

2. Initial evaluation:

   • Complete blood count to assess for anemia
   • Serum ferritin, transferrin saturation, serum iron, and total iron-binding capacity 1
   • Urinalysis to rule out hematuria 1
   • Screening for celiac disease (serological testing) 1

3. Gastrointestinal evaluation:

   • For men and postmenopausal women with iron deficiency anemia, bidirectional endoscopy (upper endoscopy and colonoscopy) is strongly recommended 1
   • Small bowel evaluation may be necessary if bidirectional endoscopy is negative 1

Important Clinical Considerations

• In postmenopausal women, median ferritin levels are typically higher (71 μg/L) compared to premenopausal women (37 μg/L) 4, making low ferritin in this population particularly concerning
• Unlike premenopausal women where menstrual blood loss is the most common cause of iron deficiency, in postmenopausal women, GI blood loss should be considered the primary cause until proven otherwise 1
• The risk of gastrointestinal malignancy is significantly higher in postmenopausal women with iron deficiency anemia compared to premenopausal women 1

Pitfalls to Avoid

• Do not assume a benign cause in postmenopausal women with low ferritin; GI malignancy must be excluded 1
• Do not overlook non-anemic iron deficiency (low ferritin without anemia), as it may still indicate significant pathology in postmenopausal women 1
• Do not interpret ferritin in isolation from other iron studies, especially in inflammatory conditions where ferritin may be falsely elevated 1
• Do not neglect celiac disease screening, as it accounts for 3-5% of iron deficiency anemia cases 1
• Do not forget to consider medication effects, particularly NSAIDs and anticoagulants 1

By systematically evaluating these potential causes, clinicians can identify and address the underlying etiology of low ferritin in menopausal women, potentially detecting serious conditions like gastrointestinal malignancies at an earlier, more treatable stage.