Therapeutic Outcomes of Hyperthyroidism: A Ten-year Investigation in an Endocrine Clinic in North of Iran

Materials and methods: This descriptive study included all hyperthyroid patients. All therapeutic results were recorded and analyzed. Results: In this study, 329 records were studied and 104 patients met the study inclusion criteria. Graves' disease (GD) and toxic adenoma were reported in 94% and 6%, respectively. Among the patients with GD, 30.5% (21.7-40.3%) did not respond to initial ATD treatment and 20% had recurrent GD despite appropriate initial response. Overall, antithyroid drugs failure occurred in 50.5% (40.45-60.55%) of the patients. Lower age, lower body mass index (BMI), high thyroid weight, and higher baseline thyroid hormone levels were associated with ATD failure (P <0.05). Patients with toxic adenomas and patients who did not respond to ATD or those who experienced relapse of hyperthyroidism received radioactive iodine or underwent surgery. Hypothyroidism occurred in 13.1% of patients with ATD alone, in 66.7% of those with surgery, and in 79.4% of the patients who received radioactive iodine (P= 0.0001). Conclusion: A significant proportion of hyperthyroid patients experience drug failure. Age, BMI, thyroid weight, and basal levels of thyroid hormones are associated with drug treatment failure. Prevalence of hypothyroidism after treatment with radioactive iodine is higher than the drug treatment alone or surgery groups.