Long COVID in Patients With Mild to Moderate Disease: Do Thyroid Function and Autoimmunity Play a Role?

Abstract

Objective Long COVID (LC) is an emerging global health issue. Fatigue is a common feature. Whether thyroid function and autoimmunity play a role is uncertain. We aimed to evaluate the prevalence and predictors of LC and the potential role of thyroid function and autoimmunity in LC. Methods We included consecutive adults without known thyroid disorder, admitted to a major COVID-19 centre for confirmed COVID-19 from July to December 2020 who had thyroid function tests (TFTs) and anti-thyroid antibodies measured on admission and at follow-up. LC was defined by the presence or persistence of symptoms upon follow-up. Results In total, 204 patients (median age: 55.0 years; 46.6% men) were reassessed at a median of 89 days (IQR: 69–99) after acute COVID-19. Forty-one (20.1%) had LC. Female (adjusted odds ratio [aOR] 2.48, p=0.018) and SARS-CoV-2 PCR cycle threshold value <25 on admission (aOR 2.84, p=0.012) independently predicted the occurrence of LC. Upon follow-up, most abnormal TFTs in acute COVID-19 resolved, and incident thyroid dysfunction was rare. Nonetheless, we observed incident anti-TPO (anti-thyroid peroxidase) positivity. While baseline or follow-up TFTs were not associated with the occurrence of LC, among 172 patients symptomatic in acute COVID-19, symptom resolution was more likely in those with positive anti-TPO upon follow-up (p=0.043). Conclusion LC is common among COVID-19 survivors, with female and those with higher viral load in acute COVID-19 particularly vulnerable. The observation of incident anti-TPO positivity warrants further follow-up for thyroid dysfunction. Whether anti-TPO plays a protective role in LC remains to be elucidated.

The Independent Association of TSH and Free Triiodothyronine Levels With Lymphocyte Counts Among COVID-19 Patients

“…Our institution, Queen Mary Hospital, is one of the major centers in Hong Kong receiving confirmed COVID-19 patients. Consecutive adult patients (aged ≥18 years) admitted to Queen Mary Hospital for COVID-19 between 21 July 2020 and 20 April 2021 were prospectively recruited ( 12 , 18 , 19 ). The presence of SARS-CoV-2 was confirmed in all patients by RT-PCR from the nasopharyngeal swab (NPS) and/or deep throat saliva (DTS), using the LightMix SarbecoV E-gene assay (TIB Molbiol, Berlin, Germany) which targeted the envelope protein (E) gene of SARS-CoV-2 as we described previously ( 20 ).…”

A prospective study of the impact of glycaemic status on clinical outcomes and anti-SARS-CoV-2 antibody responses among patients with predominantly non-severe COVID-19

“…Our previous publication has demonstrated that characteristics of COVID-19 patients admitted to Queen Mary Hospital were largely similar to those admitted to other centres in Hong Kong. Hence, our cohort is representative of COVID-19 patients in Hong Kong [13] . Consecutive adult patients (aged ≥18 years) admitted to Queen Mary Hospital for COVID-19 between 21 July 2020 and 20 May 2021 were prospectively recruited.…”

SARS-CoV-2: Emerging Role in the Pathogenesis of Various Thyroid Diseases

“…However, further studies with more sample size and lengthy follow-up are required to give a fine conclusion. 61 Furthermore, a recent case-control study found a significant correlation between hypothyroidism and prolonged SARS-CoV-2-induced anosmia and suggested that the smell dysfunction is likely due to the direct virusinduced damage on both the thyroid and olfactory nerve. 62 Moreover, this no olfactory function or slow recovery is likely because of viral-induced thyroid damage resulting in depletion of thyroid hormones may impair the regeneration and maturation of olfactory neural cells at least in a subset of cases with thyroid dysfunction.…”

“…However, further studies with more sample size and lengthy follow-up are required to give a fine conclusion. 61 …”