A study of autoimmune thyroid disorder in atomic bomb survivors in Hiroshima, (3)

To determine sequential changes in thyroid function after developing asymptomatic autoimmune thyroiditis (AAT) in A-bomb survivors, initial findings of thyrotropin-releasing hormone (TRH) test were compared with those 2 years after developing AAT (n=22) and struma (S) (n=12). According to Bastenie's classification, AAT or S patients were clinically staged into three grades. Among 17 patients who had initially had AAT I, one each developed Grade II and III two years later. Initial Grade II turned to Grade I at 2 years in 2 of 4 AAT patients and in 2 of 3 S patients. In both the AAT and S groups, Grade III remained unchanged two years later. There was no significant change in basal or peak thyroid stimulating hormone level between patients with Grade I and those with Grade II or III in both the AAT and S groups. There were no sequential changes in total and free T4, total and free T3, total cholesterol, triglyceride, and lactic dehydrogenase. The TRH test is unlikely to reflect the development of hypothyroidism. (N.K.)