The Relationship Between Severity of Hypothyroidism and Red Blood Cells Indices

Thyroid hormones have an important role in metabolism and regulation of the red blood cells (RBCs). Thyroid dysfunction induces various effects on blood cells such as anemia through reducing the oxygen metabolism. For the first time, we aimed to determine the effects of severity activation of hypothyroidism on RBCs indices in patients with hypothyroidism. This study was performed on 79 patients with hypothyroidism. Initially patients' TSH level was determined by immunoassays method, and then according to TSH ranges (0.3-5.5 µIU/mL), patients were divided into two moderate hypothyroidism (45 individuals) (TSH 6-10 µIU/mL) and marked hypothyroidism (34 individual) (TSH>10 µIU/mL) groups. Then, complete blood count was measured by cell counter. Data analysis revealed a statistically difference between the two groups of patient including moderate and marked hypothyroidism in RBCs count (4.46 versus 4.04 mil/L), hemoglobin (12.8 versus 12.3 g/dl) and hematocrit (39.8 versus 38.0 %) respectively. It seems that severly reduced hormones of thyroid may result in markedly decrease in RBCs count, hemoglobin and hematocrit. These finding are consistent with the fact that reduced thyroid hormones may cause anemia frequently through effect on cytokines involving erythropoiesis such as erythropoietin.