• 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 belowthe larynx on either side of and anterior to the trachea. The principal hormones of thyroid glandare thyroxine (T4) and triiodothyronine (T3). The current study was carried out to investigate theimpact of race, gender and area on the levels of Thyroxine (T4), Triiodothyronine (T3) and ThyroidStimulating Hormone (TSH) in normal healthy individuals. Methods: Serum levels of T4, T3 andTSH in 498 normal healthy individuals belonging to different districts of North West FrontierProvince, 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 0.3–4.8µIU/L respectively. The levels of these hormones show significant change from the referencevalues that are used in clinical laboratories as well as in Institute of Radiotherapy and NuclearMedicine (IRNUM), Peshawar, Pakistan. Conclusion: It is concluded that the age, gender, raceand area, all have an appreciable effect on the levels T4, T3 and TSH.Keywords: Thyroxine, Triiodothyronine, Thyroid Stimulating Hormone, TSH, Thyroid Hormones


Ganong. FW. Review of Medical Physiology, California:

Appleton and Lange; 1995. p.314.

Guyton WC, Hall 1E. A Textbook of Medical Physiology.

Philadelphia: W B Saunders & Co; 1996. p. 945–55.

Edwards R. Immunoassay (An Introduction), London:

William Heinemann Medical Book; 1985. p. 84, 685.

Griffin, I E.; Objeda, S. R. The Textbook of Endocrine

Physiology. New York: Oxford University Press; 1988.

pp.222 & 232.

Andreali TE, Carpenter CC1, Bannet, 1C, Plum F. Cecil

Textbook of Medicine, 4th Edition. Philadelphia: W.B.

Saunder & Co; 1997. p. 952–3.

Murry RK, Gerner PK, Mays PA, Rodwell VW. Harper's

Textbook of Biochemistry, 25th Edition. Appleton & Lange:

Stanford, 2000; p. 8.

Thorell, IL; Larson, S.M. Radioimmunoassay and related

techniques (Methodology and Clinical Applications). Saint

Louis: The CV Mosby Company; 1978. p.12, 119.

Razzak, MA. Effect of Age and Sex on Thyroid Function

Tests. Establishment of norms for the Egyptian Population in

Developments in Radioimmunoassay and Related Procedures

International Atomic Energy Agency, 1992. p.353–8.

Dashe JS, Casey BM,Well CE, Mc Intrire DD, TSH in single

and twin pregnancy ; important if gestational age – specific

reference ranges. Obstet Gynecol 2005;106:753–7

Wilson ID, Foster DW. William's Textbook of

Endocrinology, 8th Edition. Philadelphia: WB. Saunders &

Co; 1992. p.358–80.

Hollander CS, Nihei N, Burday SZ, Mitsuma T, Shenkman

L, Blum M. Clinical and laboratory observations in cases of

triiodothyronine toxicosis confirmed by radioimmunoassay.

Lancet 1972;1(7751):609–11.

Sterling K, Refetoff S, Sleekness HA. T3 thyrotoxicosis.

Thyrotoxicosis due to elevated serum triiodothyronine

levels. JAMA 1970;213:571–5.

Tietz, NW. Clinical Guide to Laboratory Test. 3rd Edition.

Philadelphia; W B Saunder & Co: 1995. p. 612.

Burroughs, V.; Shenkman, L. Thyroid function in the

elderly. Am J Med Sci 1982;283:8–17.

Burger HG, Patel TC. Thyrotrophin releasing hormone--

TSH. Clin Endrocrinol Metab 1977;6(1):83–100.

Klee GG, Hay ID. Assessment of sensitive thyrotropin

assays for an expanded role in thyroid function testing:

proposed criteria for analytic performance and clinical

utility. J Clin Endocrinol Metab 1987;64(3):461–71

Muslim S, Khalil Z. Effect of Age, Sex, Salt, Water and

Climate on T3, T4 and TSH in Healthy Individuals,

Department of Zoology Peshawar University; 2000.

Franklyn JA, Ramsden BD, Sheppard MC. The influence of

age and sex on tests of thyroid function. Am Clin Biochem


Nissinen A, Kivelä SL, Pekkanen J, Pitkänen L, Punsar S,

Kaarsalo E, et al. Thyroid function tests in elderly Finnish

men. Acta Med Scand 1986;220:63–9.

Westgren U, Burger A, Ingemansson S, Melander A, Tibblin

S, Wåhlin E. Blood levels of 3,5,3'-triiodothyronine and

thyroxine: differences between children, adults, and elderly

subjects. Acta Med Scand 1976;200:493–5.

Hesch RD, Gatz J, Pape J, Schmidt E, von zur Mühlen A.

Total and free triiodothyronine and thyroid-binding globulin

concentration in elderly human persons. Eur J Clin Invest


Hoogendoorn EH, Hermus AR, de Vegt F, Ross

HA, Verbeek AL, Kiemeney LA, et al. Thyroid function and

prevalence of anti-thyroperoxidase antibodies in a population

with borderline sufficient iodine intake: influences of age

and sex. Clin Chem 2006;52:104–11.

Sack J, Bar-On Z, Shemesh J, Becker R. Serum T4, T3 and

TBG concentrations during puberty in males. Eur J Pediatr


Campbell AJ, Reinken J, Allan BC. Thyroid disease in the

elderly in the community. Age Ageing 1981;10:47–52.

Penny R, Spencer CA, Frasier SD, Nicoloff, JT. ThyroidStimulating Hormone and Thyroglobulin Levels Decrease

with Chronological Age in Children and Adolescents. J Chin.

Endocrinol. Metab 1983; 56(1):177–80.

Hershman JM, Pekary AE, Berg L, Solomon DH, Sawin

CT. Serum thyrotropin and thyroid hormone levels in elderly

and middle-aged euthyroid persons. J Am Geriatr Soc




Most read articles by the same author(s)