Comparison of basal serum TSH concentration by immunoradiometric assay and TRH stimulation test in the diagnosis of thyroid dysfunction.

ABSTRACT

The mean basal serum TSH (IRMA) concentrations and their increments after exogenous TRH stimulation in euthyroid subjects and patients with borderline and definite hypo or hyperthyroidism were reported. In euthyroid subjects, the increment of serum TSH (IRMA) after TRH stimulation was higher in females than in males. The measurement of basal serum TSH (IRMA) alone could discriminate euthyroid subjects from patients with thyroid dysfunction. Significant correlation between basal serum TSH (IRMA) concentrations and their corresponding increment of serum TSH (IRMA) at 30 minute after TRH stimulation in the whole group of patients was observed. Therefore, the measurement of basal serum TSH (IRMA) concentration had sufficient discriminatory value in differentiating patients with or without thyroid dysfunction and obviating the need to perform TRH stimulation test.