AVP and hypopituitarism: Hyponatremia cases, possibly due to hypersecretion of antidiuretic hormone, were reported among patients with COVID-19, and some reports suggest that COVID-19 could pose a risk factor for pituitary infarction, while patients with hypopituitarism, Cushing's syndrome, and adrenal insufficiency may be susceptible to severe COVID-19 [37].