Short- and long-term impact of SARS-CoV-2 on clinical characteristics of Graves' disease patients: a retrospective cohort study.

Abstract

Background: The aim of this study was to comprehensively evaluate the effects of SARS-CoV-2 infection on treated Graves' disease (GD) patients.

Methods: This single-center retrospective cohort study included 220 patients with GD receiving stable antithyroid drug treatment. Among 179 questionnaire respondents, 107 had confirmed SARS-CoV-2 infection and 72 were uninfected. Paired thyroid function analyses were performed in 65 infected patients, and long COVID was assessed in 72 participants.

Results: In the cohort, 107 patients (77.6% female; 78.5% aged <60 years) were infected with SARS-CoV-2. COVID-19 vaccination was less frequent among infected than among uninfected participants (70.1 vs 84.7%, P = 0.025). At 12 weeks postinfection, TT3 increased from 1.76 to 1.97 nmol/L (P = 0.032), whereas TSH, FT3, FT4, TT4, and TRAb remained unchanged. Total cholesterol and HDL-C decreased after infection. TT3 changes differed by vaccination status (P for interaction = 0.019), although vaccination was not associated with biochemical thyroid function deterioration (OR: 0.88, 95% CI: 0.25-3.12). Among 72 participants who completed long COVID assessment, 37 (51.4%) met the operational definition; increased hair loss was the most common symptom. Smoking was associated with higher odds of long COVID (OR: 5.37, 95% CI: 1.05-27.36).

Conclusion: SARS-CoV-2 infection in treated GD patients was associated with modest short-term thyroid and metabolic changes, while most thyroid indices remained stable. These exploratory findings highlight the need for further prospective studies.