Effects of Thyroid Function on Blood Cell Counts and Red Cell Indices ??? A Retrospective Study at a Tertiary Care Centre in Mandya, Karnataka

Author(s): Siddegowda M.S.1, Chaithra R.2, Shivakumar S.3, Maithri C.M.4

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.
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.
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.
In case of patients with abnormal haematological parameters, thyroid hormones
evaluation is necessary.