Radioimmunoassay of thyroid related hormones and TSH in primary hyperthyroidism.

One hundred and forty seven clinically proven hyperthyroid subjects were studied using radioimmunoassay techniques for the estimation of serum thyroid hormones and pituitaryTSH concentrations. In females toxic goitre was more frequently seen in the age group 21 to 30 years and in males 31 to 40 years. The mean levels for serum T4, T3, FT4 and FT1 were significantly elevated while the mean level for serum TSH was normal. A significant positive correlation was found between T4 and T3 and between FT4 and FT1 while correlation between T4/FT4, T3/TSH and T4/TSH were found to be insignificant. Serum T3 : T4 ratio was found to be high in hyperthyroid patients. There was no significant difference in the mean of various hormones between the two sexes. Serum T3 was found to be the most sensitive single test that can be performed for the diagnosis of hyperthyroidism. (JPMA 37: 215 , 1987).