The Impact of COVID-19 (SARS-CoV-2) Virus Infection on the Endocrine System: A Review Study

The global coronavirus disease 2019 (COVID-19) pandemic is rapidly growing, and high mortality rates are reported in this regard. Coronaviruses are known to cause multi-organ system damage. Few data are available on the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on different endocrine glands. As angiotensin-converting enzyme-2 (ACE2) receptor is extensively expressed in the endocrine organs, and thus several important questions have arisen regarding whether the function of the endocrine organ changes in COVID-19 disease and patients with the SARS-CoV-2 infection develop endocrine disorders. Databases including PubMed, Web of Sciences, Scopus, and Google Scholar were searched for studies published from 1996 to February 15, 2021. New-onset diabetes mellitus has been reported by different studies at rates ranging from 5.8% to 35%. Hypercortisolism in admission time could predict disease severity. Tissues from the hypothalamus and the pituitary gland in animals are rich in ACE2, and some endocrinopathy may be secondary. Thyroiditis and thyrotoxicosis have also been recognized in the COVID-19 infection. Hypocalcemia and vitamin D deficiency may be correlated with disproportionate parathormone levels. Patients with decreased serum calcium levels had worse clinical variables and higher incidences of complications such as septic shock. Men are more susceptible to hypogonadism, and differences in the COVID-19 infection and mortality rates between males and females are due to the differential effects of estradiol and testosterone on the immune system. Considering that different glands have the ACE2 receptor, the coronavirus may be able to alter their function. Hence, this review mainly focused on COVID-19-associated endocrinopathy.