Hypothyroidism and Subclinical Hypothyroidism as a Consequence of COVID-19 Infection.

Background: Hypothyroidism occurs as a consequence of chronic autoimmune inflammation of the thyroid gland, which occurs due to the reduced function in the secretion of hormones FT3 and FT4 and requires replacement therapy for life. CoV-19 infection has shown many complications in all organic systems, during the acute phase of infection and in the post COVID period. Objectives: The aim of the study was a) to compare the frequency of patient visits for hypothyroidism and the average dose of levothyroxine in the SANASA polyclinic in the year before COVID pandemic, in the early 2019, with the frequency of patient visits during COVID infection in 2020 and 2021; b) to determine the incidence of hypothyroidism after the COVID 19 infection, the time of onset of hypothyroidism after acute phase of the disease, and the average dose of levothyroxine; and c) to monitor the incidence of subclinical hypothyroidism, which did not require substitution, before and after COVID 19 infection. Methods: In the SANASA polyclinic from the 2019 database we found 58 patients, at the age between 18-70 years, 53 women and 2 men with hypothyroidism and 2 female and 1 male patients with subclinical hypothyroidism. In 2020 there were a total of 89 patients, 73 women and 4 men with hypothyroidism, and 9 women and 3 men with subclinical hypothyroidism. In the 2021 there were 101 patients, 86 women and 7 men with hypothyroidism and 7 female and 1 male patients with subclinical hypothyroidism. Results: There was a significant difference in the number of patients with hypothyroidism and subclinical hypothyroidism during 2020 and 2021 in relation to 2019. The average dose of levothyroxine per patient did not differ statistically, comparing all three years, as well as comparing those who were ill, compared to patients who did not have COVID-19. There were diagnoses of post COVID subclinical hypothyroidism in 2020, as in 2021, with an average time of diagnosis of 2 months after infection for clinical hypothyroidism and 8 weeks for subclinical hypothyroidism. Conclusion: CoV-19 infection adversely affects thyroid tissue causing clinical hypothyroidism, requiring levothyroxine substitution as well as subclinical hypothyroidism which should be monitored.