Objectives: The aim of the present study was to investigate the effect of iron deficiency anemia and iron treatment on the thyroid functions.
Materials and methods: In this study, 42 patients and 38 healthy individuals were studied. Iron deficiency anemia was diagnosed by measurement of serum ferritin and complete blood counts. Free Triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine, total thyroxine, thyroid stimulating hormone (TSH) and cortisol levels were measured in blood samples before treatment and after two months of treatment with iron in patients group and after 12 hours of starvation in healthy controls.
Results: Before iron treatment, secondary hypothyroidism (35.7%) and subclinical hypothyroidism (16.6%) were found in patient group. Before the treatment TSH levels in the patient group were higher than the control group (p=0.001). FT3 values were not different between patient and the control groups (p>0.05). Before the treatment FT4 levels were significantly lower than the control group (p<0.001) and FT4 values significantly increased after treatment (p=0.001). Cortisol levels before treatment were significantly higher than the control group (p=0.001). Cortisol levels were significantly decreased after iron treatment in the patient group (p<0.001).
Conclusions: Secondary and subclinical hypothyroidism were found in iron deficiency anemia. Hormonal changes returned to normal values with iron supplementation.