Short and Long time Impact of SARS-CoV-2 on clinical characters of Graves' Disease Patients: A Retrospective Cohort Study

BACKGROUND: 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: Among the cohort, 107 patients (77.1% female; 69.7% aged <60 years) were infected with SARS-CoV-2. COVID-19 vaccination was less frequent among infected than uninfected participants (70.1% vs 84.7%, P = 0.025). At 12 weeks post-infection, 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 completing 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). CONCLUSIONS: SARS-CoV-2 infection in treated GD patients was associated with modest short-term thyroid and metabolic changes in treated GD patients, while most thyroid indices remained stable. These exploratory findings highlight the need for further prospective studies.