Iron deficiency; Pernicious anemia
Most cases of anemia are mild, including those that occur as a result of chronic disease. Nevertheless, even mild anemia can reduce oxygen transport in the blood, causing fatigue and a diminished physical capacity. Moderate-to-severe iron-deficiency anemia is known to reduce endurance. Some studies indicate that even iron deficiency without anemia can produce a subtle but still lower capacity for exercise.
Because a reduction in red blood cells decreases the ability to absorb oxygen from the lungs, serious problems can occur in prolonged and severe anemia that is not treated. Anemia can lead to secondary organ dysfunction or damage, including heart arrhythmia and heart failure.
Certain inherited forms of anemia, including thalassemia major, pernicious anemia, and sickle-cell anemia, can be life threatening. Thalassemia major and sickle-cell anemia affect children and are particularly devastating.
Pregnant women with significant anemia may have an increased risk for poor pregnancy outcomes, particularly if they are anemic in the first trimester.
In children, severe anemia can impair growth and motor and mental development. Children may exhibit a shortened attention span and decreased alertness. Children with severe iron-deficiency anemia may also have an increased risk for stroke.
Anemia is common in older people and can have significantly more severe complications than anemia in younger adults. Effects of anemia in the elderly include decreased strength and increased risk for falls. Anemia may have adverse effects on the heart and increase the severity of cardiac conditions, including reducing survival rates from heart failure and heart attacks. Even mild anemia may possibly lead to cognitive impairment or worsen existing dementia.
In addition to anemia, vitamin B12 deficiency can cause neurologic damage, which can be irreversible if it continues for long periods without treatment.
Anemia is particularly serious in cancer patients. In people with many common cancers, the presence of anemia is associated with a shorter survival time.
Anemia is associated with higher mortality rates and possibly heart disease in patients with kidney disease.
The combination of anemia and heart failure can increase the risk of hospitalization or death by 30 - 60%. Patients with heart failure whose hemoglobin levels decline do worse than patients with stable levels.
Blood transfusions. Patients with certain types of anemia require frequent blood transfusions. These transfusions can cause iron overload. [For more information, see "Transfusions" in Treatment section of this report.]
Alleyne M, Horne MK, Miller JL. Individualized treatment for iron-deficiency anemia in adults. Am J Med. 2008 Nov;121(11):943-8.
American College of Obstetricians and Gynecologists. ACOG Practice Bulletin No. 95: anemia in pregnancy. Obstet Gynecol. 2008 Jul;112(1):201-7.
Antony AC. Megaloblastic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 170.
Bennett CL, Silver SM, Djulbegovic B, Samaras AT, Blau CA, Gleason KJ, et al. Venous thromboembolism and mortality associated with recombinant erythropoietin and darbepoetin administration for the treatment of cancer-associated anemia. JAMA. 2008 Feb 27;299(8):914-24.
Brotanek JM, Gosz J, Weitzman M, Flores G. Iron deficiency in early childhood in the United States: risk factors and racial/ethnic disparities. Pediatrics. 2007 Sep;120(3):568-75.
Ginder GD. Microcytic and hypochromic anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 163.
Groenveld HF, Januzzi JL, Damman K, van Wijngaarden J, Hillege HL, van Veldhuisen DJ, et al. Anemia and mortality in heart failure patients a systematic review and meta-analysis. J Am Coll Cardiol.2008 Sep 2;52(10):818-27.
Killip S, Bennett JM, Chambers MD. Iron deficiency anemia. Am Fam Physician. 2007 Mar 1;75(5):671-8.
KDOQI. KDOQI Clinical Practice Guideline and Clinical Practice Recommendations for anemia in chronic kidney disease: 2007 update of hemoglobin target. Am J Kidney Dis. 2007 Sep;50(3):471-530.
Maguire JL, deVeber G, Parkin PC. Association between iron-deficiency anemia and stroke in young children. Pediatrics. 2007 Nov;120(5):1053-7.
Martí-Carvajal AJ, Solà I. Treatment for anemia in people with AIDS. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD004776.
Notebaert E, Chauny JM, Albert M. Short-term benefits and risks of intravenous iron: a systematic review and meta-analysis. Transfusion. 2007 Oct;47(10):1905-18.
Reveiz L, Gyte GM, Cuervo LG. Treatments for iron-deficiency anaemia in pregnancy. Cochrane Database Syst Rev. 2007 Apr 18;(2):CD003094.
Rizzo JD, Somerfield MR, Hagerty KL, et al. Use of epoetin and darbepoetin in patients with cancer: 2007 American Society of Clinical Oncology/American Society of Hematology Clinical Practice Guideline Update. J Clin Oncol. 2007 Dec 21 [Epub ahead of print]
Rodgers GM 3rd, Becker PS, Bennett CL, Cella D, Chanan-Khan A, Chesney C, et al. Cancer- and chemotherapy-induced anemia. J Natl Compr Canc Netw. 2008 Jul;6(6):536-64.
Zuckerman KS. Approach to the anemias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 162.
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