Effects of thyroid dysfunction on hematological parameters: Case controlled study

The thyroid gland has a very important role in hematopoiesis, blood disorders are frequently seen in patients with thyroid disorders. Thyroid hormones have direct effect on blood parameters by stimulating erythrocytes precursors and indirectly by enhancing erythropoietin production.

This is a case-control study which included 300 subjects who were grouped to 3 equal groups as a control, hypothyroidism, and hyperthyroidism groups. Patients with inherited or acquired red cell abnormalities, those receiving treatment for thyroid disorder or anemia, patient with chronic diseases, aged <12 years, pregnant ladies and patients unwilling to participate in the study were excluded.

The mean age of patients is 40.72 years, and females constituted 60.7% of cases. The analyses showed a significant difference the RBC, HB, MCV, MCHC, RDW, and WBC (P values 0.000, 0.000, 0.001, 0.012.0.002, and 0.027) respectively, while platelets showed no significant correlation (P value 0.08). The univariate analyses showed that RBC, the HB, and the WBC were the most severely affected parameters (Sig. 0.000, 0.000, and 0.005) respectively.

The study concluded that females are more affected by thyroid disorders than males and the peak age is at the forties, thyroid dysfunction affect all blood parameters except platelets.The follow up of patients with thyroid disorders should include the complete blood count and patients diagnosed with anemia should be evaluated for thyroid disorders before iron therapy. Cases of anemia that resist treatment should be investigated for the possibility of thyroid dysfunction.