Background: Thyroid hormones play a critical role in hematopoiesis, and thyroid disorders such as hypothyroidism and hyperthyroidism can affect blood parameters. Therefore, this study aimed to evaluate the effect of thyroid dysfunction on various blood parameters.
Methods: This case-control study included 194 subjects who were classified into three groups based on TSH levels: hypothyroid (n=70), hyperthyroid (n=56), and control (n=68). Conditions that affect blood parameters, including pregnancy, inherited or acquired red blood cell abnormalities, chronic inflammatory diseases, evidence of nutritional deficiencies, and underlying diseases such as cancer, as well as patients unwilling to participate in the study, were excluded. Hematological parameters were measured using a cell counter, and the results were analyzed using SPSS software.
Results: The results showed that 78% of the participants were female and 22% were male, aged 4 to 89 years. The analyses revealed that RBC, Hb, HCT, WBC count, and WBC differential count were significantly different between the three groups (P-value <0.05), but the differences were not significant for MCV, MCH, MCHC, RDW, PLT, and MPV (P-value >0.05). Correlation analysis indicated a significant correlation between TSH and Hb, HCT, WBC, PLT, neutrophils, lymphocytes, monocytes, and eosinophils (P<0.05).
Conclusion: Since thyroid hormones play a critical role in hematopoiesis, thyroid dysfunction can affect many hematological parameters. Therefore, the management of patients with thyroid disease should include the CBC test. In addition, patients with poor responses to anemia treatment may have an underlying thyroid disorder.