Effects of Thyroid Function on Blood Cell Counts and Red Cell Indices – A Retrospective Study at a Tertiary Care Centre in Mandya, Karnataka
BACKGROUND Thyroid hormones play an important role in the regulation and production of red blood cells. Thyroid dysfunction induces different effects on blood cells such as anaemia, erythrocytosis, leucopenia, thrombocytopenia and alteration in red cell indices. In this study, we wanted to compare the changes in haematological parameters of thyroid dysfunction patients with those of euthyroid group. METHODS This was a retrospective study done on 310 individuals by collecting data from the medical records. Later the patients were categorized into hypothyroid (33) thyroid stimulating hormone (TSH > 5.5 μIU/mL), hyperthyroid (19) (TSH < 0.3 μIU/mL) and euthyroid (258) (TSH = 0.3 - 5.5 μIU/ml) groups. The haematological parameters of all these patients were obtained by 5-part automated cell count analyser. Finally, the obtained data was analyzed by statistical package for social sciences (SPSS) software. RESULTS The data obtained from the analysis revealed statistically significant (P < 0.05) difference between hypothyroidism, hyperthyroidism and euthyroidism in mean red blood cell (RBC) count, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), red cell distribution width (RDW), white blood cell (WBC) count and platelet count but the difference was not significant for mean haemoglobin, mean corpuscular haemoglobin concentration (MCHC) (P > 0.05). The mean haemoglobin was lower in hypothyroid patients when compared to euthyroid and hyperthyroid patients. The RBC count (P < 0.007), MCH (P = 0.002) and RDW (P < 0.001) showed statistically significant difference between hypothyroidism and euthyroidism, MCV (P = 0.005) showed statistically significant difference between hyperthyroid and euthyroid groups. CONCLUSIONS In case of patients with abnormal haematological parameters, thyroid hormones evaluation is necessary. KEYWORDS Hypothyroidism, Hyperthyroidism, Haemoglobin, Blood Count, Red Cell Indices