Gender-specific Association between Thyroid Stimulating Hormone and Haematological Indices in Hypothyroid Patients: A Cross-sectional Study

Introduction: Hypothyroidism has long been known to cause metabolic deceleration, including its effects on haematopoietic tissue, leading to anaemia. Anaemia and hypothyroidism can co-exist and present challenges for each other, resulting in a decline in quality of life. Aim: To address the gender-specific association of Thyroid Stimulating Hormone (TSH) with various haematological indices among a cohort of hypothyroid patients. Materials and Methods: A cross-sectional observational study was conducted at a tertiary care teaching hospital in Hyderabad, Telangana, India, from October 2022 to February 2023, after obtaining ethical clearance from the institutional ethics committee. A total of 347 newly diagnosed, biochemically proven hypothyroid patients attending the hospital were included in the study. The patients were divided into subclinical and overt hypothyroid groups based on their TSH values and thyroxine levels. All patients underwent blood tests for a complete blood count, including all haematological indices such as erythrocyte count, Haemoglobin (Hb), Packed Cell Volume (PCV), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH), Mean Corpuscular Haemoglobin Concentration (MCHC), and Red cell Distribution Width (RDW). Gender-based stratification of the study population was performed. Data were analysed using the Student’s unpaired t-test, Chi-square test, and univariate linear regression with Statistical Package for the Social Sciences (SPSS) version 22.0. Results: The study highlighted a high prevalence of anaemia among overt hypothyroid patients 88 (54%) compared to subclinical hypothyroid patients 63 (34.24%). Moreover, the prevalence of anaemia was higher in females than in males. The most common type of anaemia encountered was microcytic anaemia, followed by normocytic anaemia. Linear regression analysis yielded a positive correlation between TSH and all haematological parameters, including RDW. This correlation was especially significant among females. Conclusion: TSH affected all the haematological parameters, including RDW, and the association was stronger in females as compared to males in both subclinical and overt hypothyroidism.