PeerJ (Mar 2023)

A prospective follow-up of thyroid volume and thyroiditis features on ultrasonography among survivors of predominantly mild to moderate COVID-19

  • Man Him Matrix Fung,
  • David Tak Wai Lui,
  • Keith Wan Hang Chiu,
  • Sherman Haynam Lee,
  • Chi Ho Lee,
  • Wing Sun Chow,
  • Alan Chun Hong Lee,
  • Anthony Raymond Tam,
  • Polly Pang,
  • Tip Yin Ho,
  • Carol Ho Yi Fong,
  • Connie Hong Nin Loong,
  • Chun Yiu Law,
  • Kelvin Kai Wang To,
  • Ching Wan Lam,
  • Kathryn Choon Beng Tan,
  • Yu Cho Woo,
  • Ivan Fan Ngai Hung,
  • Karen Siu Ling Lam,
  • Brian Lang

DOI
https://doi.org/10.7717/peerj.15034
Journal volume & issue
Vol. 11
p. e15034

Abstract

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Background We previously showed that higher SARS-CoV-2 viral load correlated with smaller thyroid volumes among COVID-19 survivors at 2 months after acute COVID-19. Our current follow-up study evaluated the evolution of thyroid volumes and thyroiditis features within the same group of patients 6 months later. Methods Adult COVID-19 survivors who underwent thyroid ultrasonography 2 months after infection (USG1) were recruited for follow-up USG 6 months later (USG2). The primary outcome was the change in thyroid volume. We also reassessed thyroiditis features on USG, thyroid function and anti-thyroid antibodies. Results Fifty-four patients were recruited (mean age 48.1 years; 63% men). The mean thyroid volume increased from USG1 to USG2 (11.9 ± 4.8 to 14.5 ± 6.2 mL, p < 0.001). Thirty-two patients (59.3%) had significant increase in thyroid volume by ≥15%, and they had a median increase of +33.3% (IQR: +20.0% to +45.0%). Multivariable logistic regression analysis showed that only higher baseline SARS-CoV-2 viral load independently correlated with significant thyroid volume increase on USG2 (p = 0.022). Among the seven patients with thyroiditis features on USG1, six (85.7%) had the features resolved on USG2. None had new thyroiditis features on USG2. All abnormal thyroid function during acute COVID-19 resolved upon USG1 and USG2. Conclusion Most COVID-19 survivors had an increase in thyroid volume from early convalescent phase to later convalescent phase. This increase correlated with high initial SARS-CoV-2 viral load. Together with the resolution of thyroiditis features, these may suggest a transient direct atrophic effect of SARS-CoV-2 on the thyroid gland with subsequent recovery of thyroid volume and thyroiditis features.

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