A LONG-TERM FOLLOW-UP-STUDY OF PATIENTS WITH NONTOXIC DIFFUSE GOITER IN JAPAN

OBJECTIVE Although non-toxic diffuse goitre is a common disorder, litt le is known of the clinical course of patients. We therefore decided t o investigate the long-term clinical outcome of patients with non-toxi c diffuse goitre. DESIGN A retrospective study. PATIENTS Of 850 patien ts with non-toxic diffuse goitre who met our criteria and were seen in our thyroid clinic between 1977 and 1985, 108 who had been followed f or from 5 to 14 years (mean 8 years) were entered in this study. All p atients fulfilled our criteria having soft diffuse goitres, normal ser um TSH and T4 concentrations, and undetectable antithyroglobulin and a ntithyroid microsomal antibodies. MEASUREMENTS A family history of thy roid disease was obtained and the occurrence of Graves' ophthalmopathy was noted. Serum TSH and T4 concentrations, and anti-thyroglobulin an d antithyroid microsomal antibodies were measured during the follow-up period. Thyroidal radioactive iodine uptake (RAIU), serum free T4 and free T3 concentrations, and TSH binding inhibitory immunoglobulin (TB II) activities were determined in all patients who were subsequently f ound to have abnormal serum TSH or T4 concentrations or signs of Grave s' ophthalmopathy. RESULTS Thirty-six of the 108 patients (33%) had a family history of autoimmune thyroid disease. Elevated serum T4 or fre e T4 concentrations and depressed serum TSH concentrations were found in six patients during the follow-up period. Hyperthyroid Graves' dise ase was diagnosed in four of the six patients, subacute thyroiditis in one, and transient post-partum thyrotoxicosis in one. Hypothyroidism was found in one patient who was diagnosed as having transient post-pa rtum hypothyroidism. Euthyroid Graves' disease was diagnosed in one pa tient. Furthermore, six of these eight patients had a family history o f autoimmune thyroid disease in first-degree relatives. CONCLUSION Dur ing a prolonged follow-up period of patients with non-toxic diff use g oitre, Graves' disease was found in five of 108 patients (four hyperth yroid Graves' and one euthyroid Graves'), post-partum thyroid dysfunct ion in two, and subacute thyroiditis in one. Six of these eight patien ts had a family history of autoimmune thyroid disease in first-degree relatives. Long-term follow-up is necessary for patients with non-toxi c diffuse goitre, especially those who have a family history of autoim mune thyroid disease.