Anemia, Iron Deficiency
(Low serum iron associated with low hemoglobin)

BASICS of Anemia - Iron deficiency
(Low serum iron associated with low hemoglobin)

DESCRIPTION of Anemia - Iron deficiency

• Anemia - Iron Deficiency: Low serum iron associated with low hemoglobin (Hgb) or microcytic, hypochromic red blood cells (RBCs)
• Onset acute (rapid blood loss) or chronic (slow blood loss, deficient iron intake or absorption)
• Both low Hgb per RBC and fewer RBC in total lead to blood oxygen deficiency, which can have serious systemic consequences.
• System(s) affected: hematologic, lymphatic, immunologic, cardiac, gastrointestinal




Caption: FIGURE 41.7. Anemia - Iron deficiency. The peripheral blood smear of refractory anemia with ringed sideroblasts is characterized by a dimorphic red cell population. A distinct population of hypochromic, often microcytic erythrocytes can be found admixed with normochromic, normocytic, or macrocytic erythrocytes.

Geriatric Considerations

Iron deficiency anemia is associated with increased hospitalization and mortality in older adults (1).

Pediatric Considerations

Infants who drink cow’s milk or juice, live in poverty, are from developing countries or are of black or Native American descent are at high risk of iron deficiency anemia and should get iron supplements (2)[B].

Pregnancy Considerations

Iron supplements are recommended during pregnancy to improve maternal hematologic indexes, though significant clinical outcomes have not yet been proven (3)[A] other than neonatal birth weight (2)[B].

EPIDEMIOLOGY of Anemia - Iron deficiency

Iron deficiency is the most common nutritional deficiency in the world (4,5) and iron deficiency anemia (IDA) is the most common cause of anemia (50%) (4,6). Predominant age: all ages but especially toddlers and menstruating and pregnant women

• Predominant sex: female
• Predominant race: Mexican-American and black females (4)
• Common in both developing and developed countries

Incidence

• Adults: men 2%, women 15–20% annually
• Infants and toddlers: 3–5% annually
• Pregnant patients: maybe as high as 20% (2)

Prevalence

2 billion people worldwide (5)
• Infants and children age 12 years: 4–7%
• Men: 2–5%
• Menstruating women: 30% (5)

ETIOLOGY AND PATHOPHYSIOLOGY of Anemia - Iron deficiency

Depletion of iron stores leads to decrease in both reticulocyte count and production of Hgb. Causes:
• Blood loss (menses, GI bleeding, trauma)
• Poor iron intake
• Poor iron absorption (e.g., atrophic gastritis, postgastrectomy, celiac disease)
• Increased demand for iron (e.g., infancy, adolescence, pregnancy, breastfeeding)

RISK FACTORS of Anemia - Iron deficiency

• Premenopausal woman
• Frequent blood donor
• Pregnancy/lactation, young maternal age
• Strict vegan diet
• Use of NSAIDs
• Hospitalized with frequent blood draws
• Living in or visiting countries with endemic hookworm infection

GENERAL PREVENTION of Anemia - Iron deficiency

• Screen asymptomatic pregnant women and high risk children at 1 year of age (6).
• Supplementation in asymptomatic children aged 6 to 12 months if at risk for IDA (e.g., malnutrition, abuse, cow’s milk 12 months) (2,3)
• Iron- and vitamin C-rich diet for menstruating women
• Iron 30 mg/day for asymptomatic pregnant women (3)

COMMONLY ASSOCIATED CONDITIONS of Anemia - Iron deficiency

• GI tract malignancy, peptic ulcer disease (PUD), Helicobacter pylori infection, irritable bowel disease
• Hookworm or other parasitic infestations
• Hypermetrorrhagia
• Pregnancy
• Obesity treated with gastric bypass surgery
• Malnutrition
• Medications such as NSAIDs or antacids