Prolactin level in patients hospitalized with COVID-19

Aim. To study the level of prolactin as a biomarker of the severity of COVID-19 among hospitalized patients. Design. A comparative study. Materials and methods. The study included 1,500 people with COVID-19 who were hospitalized. A simple random subsample of 250 people was formed. Patients were divided into two groups: 100 men and 150 women. The results of laboratory testing of prolactin, thyroid-stimulating hormone, and interleukin-6 levels were compared. Results. Comparative analysis revealed that women had a longer duration of the disease before admission to hospital, as well as a higher frequency of a positive PCR test result. Men had higher creatinine levels and levels of inflammatory markers upon hospitalization; they more often had comorbidities, such as coronary heart disease and chronic obstructive pulmonary disease. As a result of the assessment of hormonal parameters upon hospitalization of patients, no significant differences in the levels of prolactin and thyroid-stimulating hormone were found between the groups. The median prolactin in women was 329.32 [216.82; 572.43] mIU/L, thyroid-stimulating hormone — 1.31 [0.49; 2.21] mIU/L, in men — 282.02 [192.77; 529.28] and 1.14 [0.59; 2.57] mIU/l, respectively. In dynamics, after treatment in a hospital setting, prolactin levels decreased in both men and women (p = 0.020 and p = 0.014, respectively). Conclusion. In our study, high prolactin levels were not obtained in either group. After therapy in a specialized hospital, prolactin levels decreased in both women and men. Given the data that this hormone plays a complex role in the immune response and promotes the development of proinflammatory and anti-inflammatory responses, given the currently available research results on its levels in patients with COVID-19, further study of the contribution of prolactin to the development of the severity of infectious diseases remains relevant. Keywords: COVID-19, prolactin, hyperprolactinemia, interleukin-6, thyroid-stimulating hormone.