A prospective follow-up on thyroid function, thyroid autoimmunity and long COVID among 250 COVID-19 survivors

Long COVID and pituitary dysfunctions: a bidirectional relationship?

Long COVID is a novel emerging syndrome known to affect multiple health areas in patients previously infected by SARS-CoV-2 markedly impairing their quality of life. The pathophysiology of Long COVID is still largely poorly understood and multiple mechanisms were proposed to underlie its occurrence, including alterations in the hormonal hypothalamic-pituitary axes. Aim of this review is to present and discuss the potential negative implications of these hormonal dysfunctions in promoting and influencing the Long COVID syndrome. To date, the hypothalamic-pituitary-adrenal axis is the mostly investigated and several studies have reported a prolonged impairment leading to mild and subclinical forms of central adrenal insufficiency. Few data are also available regarding central hypogonadism, central hypothyroidism and growth hormone (GH) deficiency. A high prevalence of central hypogonadism in COVID-19 survivors several months after recovery was consistently reported in different cohorts. Conversely, very few data are available on the hypothalamic-pituitary-thyroid axis function that was mainly shown to be preserved in COVID-19 survivors. Finally, a potential impairment of the hypothalamic-GH axis in Long COVID has also been reported. These data altogether may suggest a novel possible pituitary-centred pathophysiological view of Long COVID syndrome which if confirmed by large clinical studies may have relevant implication for the diagnostic and therapeutic approach at least in a subset of patients with the syndrome.

Thyroid dysfunction in the wake of Omicron: understanding its role in COVID-19 severity and mortality

Purpose

SARS-CoV-2 can invade the thyroid gland. This study was to delineate the risk of thyroid dysfunction amidst the prevalence of the Omicron variant, and to investigate the correlation between thyroid function and Coronavirus disease 2019 (COVID-19) outcomes. The study also aimed to ascertain whether thyroid dysfunction persisted during COVID-19 recovery phase.

Methods

This was a retrospective cohort study. COVID-19 patients from the Renmin Hospital of Wuhan University, China during the epidemic of Omicron variants were included, and their thyroid function were analyzed in groups.

Results

A history of thyroid disease was not associated with COVID-19 outcomes. COVID-19 can lead to a bimodal distribution of thyroid dysfunction. The severity of COVID-19 was inversely proportional to the levels of thyroid- stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4), leading to a higher prevalence of thyroid dysfunction. Severe COVID-19 was a risk factor for euthyroid sick syndrome (ESS) (OR=22.5, 95% CI, 12.1 - 45.6). Neutrophil to lymphocyte ratio mediated the association between severe COVID-19 and ESS (mediation effect ratio = 41.3%, p < 0.001). ESS and decreased indicators of thyroid function were associated with COVID-19 mortality, while high levels of FT3 and FT4 exhibited a protective effect against death. This effect was more significant in women (p < 0.05). During the recovery period, hyperthyroidism was quite uncommon, while a small percentage of individuals (7.7%) continued to exhibit hypothyroidism.

Conclusion

COVID-19 severity was linked to thyroid dysfunction. Severe COVID-19 increased the risk of ESS, which was associated with COVID-19 mortality. Post-recovery, hyperthyroidism was rare, but some individuals continued to have hypothyroidism.

Risk of Incident Thyroid Dysfunction in the Post-Acute Phase of COVID-19: A Population-Based Cohort Study in Hong Kong

OBJECTIVE

The evidence of thyroid dysfunction in the post-acute phase of SARS-CoV-2 infection is limited. This study aimed to evaluate the risk of incident thyroid dysfunction in the post-acute phase of COVID-19.

METHODS

This retrospective, propensity-score matched, population-based study included COVID-19 patients and non-COVID-19 individuals between January 2020 and March 2022, identified from the electronic medical records of the Hong Kong Hospital Authority. The cohort was followed up until the occurrence of outcomes, death, or 31 January 2023, whichever came first. Patients with COVID-19 were 1:1 matched to controls based on various variables. The primary outcome was a composite of thyroid dysfunction (hyperthyroidism, hypothyroidism, initiation of antithyroid drug or levothyroxine, and thyroiditis). Cox regression was employed to evaluate the risk of incident thyroid dysfunction during the post-acute phase.

RESULTS

A total of 84 034 COVID-19 survivors and 84 034 matched controls were identified. Upon a median follow-up of 303 days, there was no significant increase in the risk of diagnosed thyroid dysfunction in the post-acute phase of COVID-19 (hazard ratio [HR] 1.058, 95% confidence interval 0.979-1.144, P = .154). Regarding the secondary outcomes, patients with COVID-19 did not have increased risk of hyperthyroidism (HR 1.061, P = .345), hypothyroidism (HR 1.062, P = .255), initiation of antithyroid drug (HR 1.302, P = .070), initiation of levothyroxine (HR 1.086, P = .426), or thyroiditis (P = .252). Subgroup and sensitivity analyses were largely consistent with the main analyses.

CONCLUSION

Our population-based cohort study provided important reassuring data that COVID-19 was unlikely to be associated with persistent effects on thyroid function.

Thyroid dysfunction in COVID-19

The COVID-19 pandemic has affected over 772 million people globally. While lung damage is the major contributor to the morbidity and mortality of this disease, the involvement of multiple organs, including the endocrine glands, has been reported. This Review aims to provide an updated summary of evidence regarding COVID-19 and thyroid dysfunction, incorporating highlights of recent advances in the field, particularly in relation to long COVID and COVID-19 vaccination. Since subacute thyroiditis following COVID-19 was first reported in May 2020, thyroid dysfunction associated with COVID-19 has been increasingly recognized, secondary to direct and indirect effects on the hypothalamic-pituitary-thyroid axis. Here, we summarize the epidemiological evidence, pattern and clinical course of thyroid dysfunction following COVID-19 and examine radiological, molecular and histological evidence of thyroid involvement in SARS-CoV-2 infection. Beyond acute SARS-CoV-2 infection, it is also timely to examine the course and implication of thyroid dysfunction in the context of long COVID owing to the large population of survivors of COVID-19 worldwide. This Review also analyses the latest evidence on the relationship between the therapeutics and vaccination for COVID-19 and thyroid dysfunction. To conclude, evidence-based practice recommendations for thyroid function testing during and following COVID-19 and concerning COVID-19 vaccination are proposed.

A prospective study on endocrine function in patients with long-COVID symptoms

OBJECTIVE

To investigate hormonal status in patients with long-COVID and explore the interrelationship between hormone levels and long-COVID symptoms.

DESIGN

Prospective observational study.

PARTICIPANTS

Patients who visited our long-COVID outpatients' clinic due to long-COVID symptoms from February 2021 to December 2022.

MEASUREMENTS

Total triiodothyronine, free thyroxine, thyrotropin, thyroglobulin, anti-thyroperoxidase, and antithyroglobulin autoantibodies were measured for thyroid assessment. Other hormones measured were growth hormone, insulin-like growth factor 1 (IGF-1), adrenocorticotropic hormone (ACTH), serum cortisol, dehydroepiandrosterone sulfate (DHEA-S), total testosterone, plasma insulin, and C-peptide. Blood glucose and glycosylated hemoglobin were also measured. To assess adrenal reserve, an ACTH stimulation test was performed. The fatigue assessment scale (FAS) was used to evaluate fatigue severity.

RESULTS

Eighty-four adult patients were included. Overall, 40.5% of the patients had at least one endocrine disorder. These included prediabetes (21.4%), low DHEA-S (21.4%), subclinical hypothyroidism (3.6%), non-specific thyroid function abnormality (7.1%), thyroid autoimmunity (7.1%), low testosterone in males (6.6%), and low IGF-1 (3.6%). All patients had normal adrenal reserve. Long-COVID-19 symptoms were present in all patients and the most commonly reported symptom was fatigue (89.3%). The FAS score was higher than normal (≥ 22) in 42.8% of patients. There were no associations between patients' symptoms and hormone levels. Diabetic patients reported confusion (p = 0.020) and hair loss (p = 0.040) more often than non-diabetics.

CONCLUSIONS

The evaluation of endocrine function 3 months after a positive SARS-CoV2 test revealed only subclinical syndromes. The vast majority of patients reported mainly fatigue, among other symptoms, which were unrelated, however, to endocrine function.

The Growing Understanding of the Pituitary Implication in the Pathogenesis of Long COVID-19 Syndrome: A Narrative Review

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation. This can result in symptoms such as fatigue, changes in appetite, and mood disturbances. Long COVID-19, the persistent and often debilitating condition following acute COVID-19 infection, may be explained by deficiencies in ACTH and Growth hormone production from the pituitary gland. Corticotropin insufficiency can result in the dysregulation of the body's stress response and can lead to prolonged feelings of stress, fatigue, and mood disturbances in Long COVID-19 patients. Simultaneously, somatotropin insufficiency can affect growth, muscle function, and energy metabolism, potentially causing symptoms such as muscle weakness, exercise intolerance, and changes in body composition. Recently, some authors have suggested the involvement of the pituitary gland in Post COVID-19 Syndrome. The exact mechanisms of viral action on infected cells remain under discussion, but inflammatory and autoimmune mechanisms are primarily implicated. The aim of our study will be to review the main pituitary complications following COVID-19 infection. Moreover, we will explain the possible involvement of the pituitary gland in the persistence of Post COVID-19 Syndrome.

The Role of Extracellular Vesicles in SARS-CoV-2-Induced Acute Kidney Injury: An Overview

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected millions worldwide since its outbreak in the winter of 2019. While extensive research has primarily focused on the deleterious respiratory effects of SARS-CoV-2 in recent years, its pan-tropism has become evident. Among the vital organs susceptible to SARS-CoV-2 infection is the kidney. Post SARS-CoV-2 infection, patients have developed coronavirus disease 19 (COVID-19), with reported incidences of COVID-19 patients developing acute kidney injury (AKI). Given COVID-19's multisystemic manifestation, our review focuses on the impact of SARS-CoV-2 infection within the renal system with an emphasis on the current hypotheses regarding the role of extracellular vesicles (EVs) in SARS-CoV-2 pathogenesis. Emerging studies have shown that SARS-CoV-2 can directly infect the kidney, whereas EVs are involved in the spreading of SARS-CoV-2 particles to other neighboring cells. Once the viral particles are within the kidney system, many proinflammatory signaling pathways are shown to be activated, resulting in AKI. Hence, clinical investigation of urinary proinflammatory components and total urinary extracellular vesicles (uEVs) with viral particles have been used to assess the severity of AKI in patients with COVID-19. Remarkedly, new emerging studies have shown the potential of mesenchymal stem cell-derived EVs (MSC-EVs) and ACE2-containing EVs as a hopeful therapeutic tool to inhibit SARS-CoV-2 RNA replication and block viral entry, respectively. Overall, understanding EVs' physiological role is crucial and hopefully will rejuvenate our therapeutic approach towards COVID-19 patients with AKI.

Beyond Acute COVID-19: Investigating the Incidence of Subacute Thyroiditis in Long COVID-19 in Korea

BACKGRUOUND

The correlation between acute coronavirus disease 2019 (COVID-19) and subacute thyroiditis (SAT) has not been clearly investigated in "long COVID" patients. We aimed to investigate the incidence of SAT during convalescence and after the acute phase of COVID-19, comparing with that of the general population.

METHODS

Data from a total of 422,779 COVID-19 patients and a control group of 2,113,895 individuals were analyzed. The index date was defined as the date 3 months after confirmation of COVID-19. The incidence rate (IR) of SAT and hazard ratios (HRs) were calculated per 100,000 persons. Subgroup analysis included analysis of HRs 90-179 and 180 days post-COVID-19 diagnosis; and additional analysis was conducted according to hospitalization status, sex, and age group.

RESULTS

The IR of SAT was 17.28 per 100,000 persons (95% confidence interval [CI], 12.56 to 23.20) in the COVID-19 group and 8.63 (95% CI, 6.37 to 11.45) in the control group. The HR of COVID-19 patients was 1.76 (95% CI, 1.01 to 3.06; P=0.045). The HR of SAT was 1.39 (95% CI, 0.82 to 2.34; P=0.220) up to 6 months after the index date and 2.30 (95% CI, 1.60 to 3.30; P<0.001) beyond 6 months. The HR for SAT among COVID-19 patients was 2.00 (95% CI, 1.41 to 2.83) in hospitalized patients and 1.76 (95% CI, 1.01 to 3.06) in non-hospitalized patients compared to the control group. The IR of SAT was 27.09 (95% CI, 20.04 to 35.82) for females and 6.47 (95% CI, 3.34 to 11.30) for males. In the 19 to 64 age group, the IR of SAT was 18.19 (95% CI, 13.70 to 23.67), while the IR was 9.18 (95% CI, 7.72 to 10.84) in the 65 to 69 age group.

CONCLUSION

SAT could be a potential long-term complication of COVID-19. Long-term surveillance for thyroid dysfunction is needed especially in hospitalized, female and young-aged subjects.

The Spectrum of Thyroid Function Tests and Autoantibodies During Hospitalization and After Six Months of Discharge in COVID-19 Patients: Does COVID-19 Trigger Autoimmunity?

OBJECTIVE

The aim of the study was to investigate thyroid function test (TFT) results and anti-thyroid antibody titers in acutely infected COVID-19 patients, as well as the changes in TFT and autoantibody results during the 6-months recovery period among survivors.

PATIENTS AND DESIGN

A total of 163 adult COVID-19 patients and 124 COVID-19 survivors were evaluated in terms of TFT (thyroid stimulating hormone [TSH], free triiodothyronine [fT3], and free thyroxine [fT4]) and anti-thyroid antibodies (anti-thyroglobulin [anti-Tg] and anti-thyroid peroxidase [anti-TPO]).

RESULTS

Thyroid dysfunction was noted in 56.4% of patients on admission, including the non-thyroidal illness syndrome (NTIS) in most cases. Presence vs. absence of thyroid dysfunction on admission was associated with significantly higher rate of severe disease (p < 0.001), while severe vs. mild-to-moderate disease was associated with significantly lower serum fT3 levels (p = 0.001). Overall, 94.4% of survivors were euthyroid at the time of 6 months post-discharge, while in some patients, the post-COVID-19 recovery period was also associated with significantly increased anti-TPO titers and the presence of new-onset or persistent subclinical hypothyroidism.

CONCLUSION

This is one of the few studies to evaluate TFT and autoantibodies over a 6-month period after recovery from COVID-19. The presence of emergent or persistent subclinical hypothyroidism and the significantly increased anti-TPO titers in some patients during the convalescence period suggest the need for follow-up for development of thyroid dysfunction and autoimmunity among COVID-19 survivors.

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

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.