From the Guidelines
Thyroid disease can indeed cause anemia, as both hypothyroidism and hyperthyroidism can lead to various types of anemia through different mechanisms. In the context of managing adults with 22q11.2 deletion syndrome, thyroid disease is common, with nearly 1 in 4 requiring treatment for primary hypothyroidism and 1 in 20 having hyperthyroidism 1. Hypothyroidism can cause normocytic anemia due to decreased bone marrow activity and red blood cell production, while hyperthyroidism can lead to anemia through increased red blood cell turnover and shortened cell lifespan. Some key points to consider include:
- Decreased thyroid hormone production in hypothyroidism can reduce bone marrow activity, resulting in normocytic anemia
- Hypothyroidism can also cause macrocytic anemia due to vitamin B12 and folate malabsorption
- Hyperthyroidism can cause anemia through increased red blood cell turnover and shortened cell lifespan
- Autoimmune thyroid conditions like Hashimoto's thyroiditis or Graves' disease may be associated with other autoimmune conditions that cause anemia Given the potential for thyroid disease to cause anemia, it is essential to assess thyroid function annually and address any underlying thyroid conditions to resolve anemia. If symptoms like fatigue, weakness, pale skin, or shortness of breath are present, a complete blood count should be performed to check for anemia, and both conditions should be addressed appropriately 1.
From the Research
Relationship Between Thyroid Disease and Anemia
- Thyroid hormones play a role in stimulating erythropoiesis, and their absence can lead to anemia 2.
- Anemia can be a clinical condition accompanying thyroid diseases, with normocytic anemia being the most common form 3.
- The causative relationship between thyroid disease and anemia is complex, with thyroid dysfunction potentially leading to anemia through various mechanisms, including bone marrow depression, decreased erythropoietin production, and comorbid diseases 3, 4.
Types of Anemia Associated with Thyroid Disease
- Normocytic anemia is the most common form of anemia associated with thyroid disease 3.
- Macrocytic or microcytic anemia can also occur in the course of thyroid dysfunction 3, 2.
- Iron-deficiency anemia can negatively influence thyroid hormone status, and treating subclinical hypothyroidism can improve anemia in patients with coexisting iron-deficiency anemia 5, 4.
Management of Anemia in Thyroid Disease
- Restoration of thyroid function, as well as specific hematinic therapy, is often required to correct anemia in patients with thyroid disease 2.
- Adding iron to thyroxine therapy can improve both anemia and thyroid function in patients with subclinical hypothyroidism 4, 6.
- Proper management of anemia, including blood transfusion and chelation, can help prevent deterioration of thyroid function in patients with chronic hemolytic anemia 6.