Endocrine Abstracts

Introduction: COVID-19 is a viral infection that can affect various endocrine tissues, including the thyroid. In some patients, symptoms may persist after the infection, defined as Long COVID. Given the similarity of some of these symptoms to those encountered in thyroid disorders, we have decided to assess thyroid function in patients previously infected with SARS-CoV-2.

Patients & Methods: This was a prospective study conducted from January to December 2022 in the Endocrinology Department of Farhat Hached University Hospital in Sousse, including patients previously infected with SARS-CoV-2, completely recovered (G1), and patients experiencing Long COVID (G2). A thyroid function assessment was performed by measuring TSH and FT4 levels.

Results: A cohort of 64 patients underwent hormonal evaluation, and the median duration for hormonal exploration was comparable between G1 (fully recovered) and G2 (Long COVID), with respective values of 11.5 months [Q1–Q3]=[9-14] and 11 months [Q1–Q3]=[6-14] (P=0.498). Predominant manifestations in the Long COVID group included asthenia and cognitive disturbances, observed in 84.4% and 93.8% of cases, respectively. Mean TSH levels were 5.19 ± 16.12 mIU/l for G1 and 4.33 ± 14.38 mIU/l for G2 (P=0.702), while mean FT4 concentrations were 9.60 ± 2.25 pg/ml for G1 and 10.06 ± 1.93 pg/ml for G2 (P=0.388). Within G1, two instances of overt peripheral hypothyroidism were identified, constituting 6.3% of the patients, compared to one case in G2, representing 3.1% of patients. Notably, these cases exhibited positive antithyroid antibodies. No occurrences of central hypothyroidism were observed in the study cohort.

Conclusion: Despite potential symptom overlap between dysthyroid conditions, notably hypothyroidism, and Long COVID, our findings suggest that thyroid dysfunction does not contribute significantly to the pathogenesis of the post-COVID-19 syndrome. Our study aligns with the prevailing evidence from most investigations evaluating thyroid function in the phase following SARS-CoV-2 infection.