An improved approach to thyroid function testing in patients with non-thyroidal illness.
We have compared the results of serum thyrotrophin (TSH) measurements using a sensitive immunoradiometric assay (IRMA) with those of conventional thyroid function tests in 299 hospital inpatients with a range of non-thyroidal illnesses. Levels of total thyroxine (T4), free T4, total tri-iodothyronine (T3) and free T3 in the hypothyroid range were recorded in 8%, 15%, 19% and 49% of patients, respectively, whereas TSH (IRMA) was abnormally low in 1%. Furthermore, basal TSH (IRMA) accurately predicted the result of the thyrotrophin-releasing hormone test in 72 of the 74 patients in whom this test was performed and, unlike thyroid hormone measurement, identified patients with subclinical thyroid disease. It would appear that a single basal TSH (IRMA) measurement is the most appropriate screening test for thyroid dysfunction in patients with concomitant acute or chronic illness.
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis; D007037:Hypothyroidism / Q000175:diagnosis; D007118:Immunoassay; D008297:Male; D008875:Middle Aged; D013960:Thyroid Function Tests / Q000379:methods*; D013972:Thyrotropin / Q000097:blood; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology; D013974:Thyroxine / Q000097:blood
D013973:Thyrotropin-Releasing Hormone; D013972:Thyrotropin; D013974:Thyroxine