Normal adrenal and thyroid function in patients who survive COVID-19 infection.

Context The COVID-19 pandemic continues to exert an immense burden on global health services. Moreover, up to 63% of patients experience persistent symptoms, including fatigue, after acute illness. Endocrine systems are vulnerable to the effects of COVID-19 as many glands express the ACE2 receptor, used by the SARS-CoV-2 virion for cellular access. However, the effects of COVID-19 on adrenal and thyroid gland function after acute COVID-19 remain unknown. Objectives Our objectives were to evaluate adrenal and thyroid gland function in COVID-19 survivors. Design A prospective, observational study was undertaken. Setting Clinical Research Facility, Imperial College NHS Healthcare Trust. Participants Seventy patients ≥ 18 years at least 3 months after diagnosis of COVID-19 were included. Intervention Participants attended a research study visit (08:00-09:30), during which a short Synacthen test (250 µg IV bolus), and thyroid function assessments were performed. Results All patients had a peak cortisol ≥450 nmol/l after Synacthen, consistent with adequate adrenal reserve. Basal and peak serum cortisol did not differ according to disease severity or history of dexamethasone treatment during COVID-19. There was no difference in baseline or peak cortisol after Synacthen or in thyroid function tests, or thyroid status, in patients with fatigue (n=44) compared to those without (n=26). Conclusions Adrenal and thyroid function ≥3 months after presentation with COVID-19 was preserved. Whilst a significant proportion of patients experienced persistent fatigue, their symptoms were not accounted for by alterations in adrenal or thyroid function. These findings have important implications for the clinical care of patients after COVID-19.