RESUMO
To evaluate the effect of thyroid hormones on the production of hemoglobin A2 and F [Hb A2 and F]. Sixty three patients were enrolled in this study including new cases of hyperthyroidism, hypothyroidism and thalassemia minor; 28 healthy subjects were used as control group. Assessment of Hb A2, Hb F levels as well as measurement of thyroid hormones were performed for each of them. Hb A2 was significantly higher in hyperthyroid patients than in control group [P=0.002], while Hb F was significantly higher in hypothyroid group in comparison with the control [P=0.012]. Hemoglobin A2 levels are increased in hyperthyroidism and decreased in hypothyroidism, unlike hemoglobin F. This may clarify the effect of thyroid hormones on globin chain synthesis