Thyrotropin results in euthyroid patients with a past history of hyperthyroidism.
Sensitive TSH levels were measured in 93 euthyroid patients with a past history of hyperthyroidism. Subnormal TSH values were found in 18 out of 75 (24%) patients previously treated with a course of antithyroid drugs, and in 3 out of 18 (17%) post-thyroidectomy patients. These subnormal TSH results are a limitation to the general application of the TSH-first strategy. Twelve months follow-up showed that subnormal TSH values are associated with increased risk of relapse in the antithyroid drug treated group (p less than 0.001). Longer follow-up varies in duration and some late relapses have occurred in drug treated patients with normal baseline TSH levels. To date relapses have occurred in 3 out of 56 normal TSH patients compared with in 6 out of 16 suppressed TSH patients; no thyroidectomy patients have relapsed. Prospective studies are needed to confirm the predictive value of sensitive TSH measurements.
Department of Nuclear Medicine, Christchurch Hospital, New Zealand.
B E
BE
Brownlie
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HM
Legge
D000293:Adolescent; D000328:Adult; D000368:Aged; D013956:Antithyroid Agents / Q000627:therapeutic use*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D013960:Thyroid Function Tests; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood*
D013956:Antithyroid Agents; D013972:Thyrotropin