Characteristics of anemia in hypothyroid patients

Q: Hypothyroidism tends to cause? (select one)

A) Macrocytic anemia

B) Microcytic anemia

Answer: A

In hypothyroidism, macrocytic anemia occurs due to various etiologies. Interestingly, these patients may have normal vitamin B12, folate, and iron levels. Not all patients, but some patients may resolve this macrocytosis after thyroxine replacement. MCV in these patients is usually in the range of 90 to 100 fL

A particular subtype of this disease process is autoimmune hypothyroidism, where autoantibodies to gastric parietal cells may have concomitant vitamin B12 deficiency. This situation may co-exist with pernicious anemia.

#hematology

#endocrinology

References:

1. Szczepanek-Parulska E, Hernik A, Ruchała M. Anemia in thyroid diseases. Pol Arch Intern Med. 2017 May 31;127(5):352-360. doi: 10.20452/pamw.3985. Epub 2017 Mar 28. PMID: 28400547.

2. Antonijević N, Nesović M, Trbojević B, Milosević R. Anemije u hipotireozi [Anemia in hypothyroidism]. Med Pregl. 1999 Mar-May;52(3-5):136-40. Croatian. PMID: 10518398.

3. Erdogan M, Kösenli A, Ganidagli S, Kulaksizoglu M. Characteristics of anemia in subclinical and overt hypothyroid patients. Endocr J. 2012;59(3):213-20. doi: 10.1507/endocrj.ej11-0096. Epub 2011 Dec 27. Erratum in: Endocr J. 2013;60(4):541. Mehmet, Erdogan [corrected to Erdogan, Mehmet]; Aybike, Kosenli [corrected to Kösenli, Aybike]; Mustafa, Kulaksizoglu [corrected to Kulaksizoglu, Mustafa]. PMID: 22200582.