Red Blood Cell Indices and Hypothyroidism

Abstract

Background: Hypothyroidism is a commonly encountered endocrine problem throughout the world which can cause various morphological types of anaemia with various underlying pathogenesis. So, the proper evaluation of RBC indices is important to manage the cases of refractory anaemia in patients with thyroid dysfunction.
Aims: To estimate the mean values of Hemoglobin and RBC indices in hypothyroid and euthyroid status and to determine the significance of association of the RBC indices between hypothyroid group in comparison to euthyroid group.
Material and Methods: Total 400 adult non-pregnant patients were included in this hospital based cross sectional study. Blood samples were analysed for Hemoglobin level and RBC indices by 5-part cell counter and TSH level by Electrochemiluminescence method. RBC indices of hypothyroid group was compared with that of the control group (euthyroid) and student t test and Pearson correlation was applied to determine any significant association between these haematological parameters and functional status of thyroid gland.
Results: 258 (64.5%) patients were categorized as euthyroid group and rest 142 (33.5%) were categorized as hypothyroid group. Hypothyroid group of patients had significantly lower level of Hb with lower MCV, MCH and MCHC compared to euthyroid group (p<0.05, unpaired t test) while RDW-CV is higher indicating more anisocytosis in case of hypothyroid group.
Conclusion: Hypothyroidism is a leading cause of anaemia with decreased level of Hemoglobin and has a significant impact on most of the RBC indices. Hence evaluation of thyroid function is important to evaluate causes of anemia specially with altered RBC indices.