The Reference range Intervals of thyroid hormones for under 21 years in South - east of Caspian Sea- Iran

Thyroid disorder and hypothyroidism in particular correlated with mental and growth abnormality in children. The aim of this study was to determine the reference intervals,of thyroid stimulating hormone (TSH). thyroxin (T4) and triodothyronine (T3), of children and adolescent, in northern Iran, and to assess whether thyroid hormones are age and gender related in this region. The sample population for this study consist of subjects of 4 age groups up to 21 years. the subjects were selected randomly from people referred to Danesh Medical Diagnostic laboratory in Gorgan northern Iran, located in the South east of Caspian Sea : The Sample were divided on the basis of ages in 4 groups of 1-5, 6-10, 11-15, 16-21 years, and the thyroid hormone level, were investigated with Radio immunoassay. The mean concentration for, T4, T3 TSH, for the sample population of 5 groups were as follow (113.5, 107.4, 102.9, 99.2, nmol/L), (1.9, 1.7, 1.9, 1.6nmol/L), and (2.1, 3.5, 2.9, 2.7, mlu/L). The mean value of T3 TSH were higher for females but the mean value of T4 was slightly higher in males. the finding o this investigation indicated that there is an inverse age correlation in particular for T4 in all age groups. on the bases of the results from this Study, we conclude that T4 reference, range intervals level are age, related inversely in all age groups. and lower, upper limits of our reference interval are not universally similar, therefore determination of reference range in each region is a critical need for clinical diagnosis.