In China, due to the risks of hypothyroidism after radioiodine treatment, radioiodine is not commonly used as a first-line treatment. In this study, factors influencing the development of hypothyroidism after 131I therapy for Graves' hyperthyroidism were evaluated. This was a retrospective study with a 12-month follow-up. Retrospectively, we investigated 1,264 patients with diagnosed Graves' disease who received 131I therapy using the Marinelli-Quimby formula. The first three months after 131I therapy, hypothyroidism risk was higher among patients with lighter thyroid weight, higher levels of thyroglobulin antibody (TGAb), and shorter durations of Antithyroid drug (ATD) treatment before 131I therapy (P < 0.05). After 6 months, patients with lighter thyroid weight, shorter ATD treatment duration before 131I therapy, and higher iodine intake showed an increased risk of hypothyroidism. (P < 0.05). After one year, lower 24-h iodine uptake was the only risk factor for hypothyroidism (P < 0.05). Our results show that 131I is an effective therapy for GD. Even if over time, the occurrence of hypothyroidism may ultimately depend on the patients' radiosensitivity to 131I before treatment. But in the first 3 to 6 months or even one year, we can still take measures to effectively improve the quality of life of patients.
Keywords: 131I therapy; Graves’ disease; Hyperthyroidism; Hypothyroidism.
© 2024. The Author(s).