Zahoor Ahmed, Mudassir Ahmad Khan, Amin ul Haq, Salma Attaullah, Jamil ur Rehman


Background: Thyroid is one of the ductless endocrine gland, which is located immediately below
the larynx on either side of and anterior to the trachea. The principal hormones of thyroid gland
are thyroxine (T4) and triiodothyronine (T3). The current study was carried out to investigate the
impact of race, gender and area on the levels of Thyroxine (T4), Triiodothyronine (T3) and Thyroid
Stimulating Hormone (TSH) in normal healthy individuals. Methods: Serum levels of T4, T3 and
TSH in 498 normal healthy individuals belonging to different districts of North West Frontier
Province, Pakistan, were examined. Serum T4 and T3 were analysed by Radio Immuno Assay
(RIA) method whereas TSH was estimated by Immunoradiometric assay (IRMA) method.
Results: Levels of T4, T3 and TSH ranged from 53 to 167 ηmol/L, 0.6 to 3.1 ηmol/L and 0.3–4.8
µIU/L respectively. The levels of these hormones show significant change from the reference
values that are used in clinical laboratories as well as in Institute of Radiotherapy and Nuclear
Medicine (IRNUM), Peshawar, Pakistan. Conclusion: It is concluded that the age, gender, race
and area, all have an appreciable effect on the levels T4, T3 and TSH.
Keywords: Thyroxine, Triiodothyronine, Thyroid Stimulating Hormone, TSH, Thyroid Hormones

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