Trends in Management and Outcomes of Pediatric Hyperthyroidism Over Two Decades

Background: Over recent decades, variations have been observed in the incidence of pediatric hyperthyroidism (HT) and Graves’ disease (GD), preferred treatment modalities, and long-term outcomes. This study aimed to evaluate trends and long-term outcomes of pediatric HT across a 20-year period in a large cohort. Methods: We conducted a retrospective study using the electronic database of a large health maintenance organization. Children aged 2–18 years who were diagnosed with HT between 2000 and 2019, received antithyroid drugs (ATDs) for at least 6 months, and were followed up through 2024 were included in the analysis. Results: Of 5,111,304 insured children, 518 (75% females) met the inclusion criteria. The median age at diagnosis was 15.1 (13.0–16.5) years, and the median follow-up was 10.4 (6.5–15.1) years. The median ATD treatment duration was 3.8 (1.8–6.6) years. The mean initial methimazole dose decreased from 15.8 (8.5–23.4) mg/day in 2000–2009 to 12.9 (7.3–19.4) mg/day in 2010–2019 ( p = 0.030). The overall remission rate was 31.1%. Compared with children diagnosed in 2000–2009, those diagnosed in 2010–2019 were less likely to undergo definitive treatment (27.5% vs. 59.6%, p < 0.001) and had higher nonremission (19.0% vs. 3.8%, p < 0.001) and relapse rates (15.9% vs. 4.6%, p < 0.001). Among the 161 children achieving remission, the median time to remission was 2.36 years. Younger age and antithyroid peroxidase positivity were associated with later remission ( p = 0.010 and p = 0.018, respectively). Higher baseline free thyroxine levels at diagnosis were found in children with late remission than in those with early remission (42.4 [26.7–61.5] vs. 32.6 [24.4–42.5] pmol/L , p = 0.014). Conclusions: Over the past two decades, the management of pediatric HT has evolved toward more prolonged medical therapy and decreased reliance on definitive treatments. This change in practice appears to coincide with an increased relapse rate, underscoring the clinical implications of these changes. Future studies should focus on evaluating the influence of these treatment strategies on the long-term prognosis of children with pediatric HT.