Thyroid and Its Regulatory Hormonal Homeostasis in Current and the Former Smokers (Report‪)‬

Byline: Nabila Roohi and Rukhsana Nazir - Email: nabilaruhi@gmail.com Abstract.- Effect of cigarette smoking on serum thyroid hormones, i.e., thyroxine (T4) and tri-iodothyronine (T3) and their regulatory hormone, i.e., thyrotropin (TSH) was evaluated in male current smokers (n=80), ex -smokers (n=50) and never smokers (n=50), ages ranging 30-60 years. Current smokers were categorized as group I (n=40) including short duration (1-5 years) and group II (n=40) including long duration (6-30 years) smokers. Body mass index (BMI), blood pressure (BP) and heart rate (HR) were also recorded. Enzyme-linked-Immunosorbent Assay was used to estimate levels of T 4, T3 and TSH. T4 varied non-significantly in comparable groups. T 3 and TSH were found to be significantly elevated in current compared to never smokers. Elevation in TSH was more intensified in group II compared to group I. Ex-smokers indicated a significant rise in T3 when compared with never smokers.