[Dynamics the parameters of mineral metabolism in hospitalized patients with COVID-19, the impact of etiotropic and pathogenetic therapy].

The high prevalence of COVID-19 requires the research progress on the disease pathogenesis. There is a lot of data confirming the association between mineral metabolism and the severity of COVID-19.

Aim: To study the dynamics of mineral metabolism parameters in patients with a confirmed COVID-19 at the time of hospitalization and after discharge, including the impact of etiotropic and pathogenetic therapy on them.

Materials and methods: A single-center study of 106 patients (aged ≥18 years) with clinically or laboratory confirmed diagnosis of COVID-19 was carried out at the Endocrinology Research Centre, Moscow. Baseline biochemical parameters, including serum calcium, phosphorus, albumin, 25(OH)D, parathyroid hormone (PTH), inflammatory markers, and instrumental assessment of COVID-19 severity were performed before specific immunotherapy, as well as on 3rd and 7th days of hospitalization and before discharge. Statistical analysis was performed with Statistica 13 software (StatSoft, USA).

Results: On the first day, hypocalcemia (low albumin-adjusted calcium level) was detected in 40.6% of cases, the prevalence of vitamin D deficiency/insufficiency amounted to 95.3% of cases. At the same time, secondary hyperparathyroidism was identified only in 14.2% of patients. A comparative analysis of mineral metabolism during hospitalization (between 1, 3, 7 days of hospitalization and before discharge) during baricitinib treatment revealed a statistically significant increase in albumin-adjusted calcium by the end of hospitalization (p<0.001, Friedman criterion, Bonferroni correction p0=0.01). A pairwise comparison of subgroups, depending on the therapy, revealed a statistically significantly lower level of albumin-adjusted calcium on 3rd day among patients on baricitinib monotherapy or combined with tocilizumab compared with a subgroup of patients undergoing etiotropic treatment (2.16 [2.13; 2.18] mmol/l vs 2.23 [2.19; 2.28] mmol/l, p=0.002, U-test, Bonferroni correction p0=0.012).

Conclusion: Patients with severe coronavirus infection are characterized by a high prevalence of vitamin D deficiency and hypocalcemia. Associations between calcium and saturation as well as the severity of lung lesion characterizes hypocalcemia as an important predictor of severe course and poor outcome in COVID-19. Pathogenetic therapy with baricitinib, including in combination with tocilizumab, contributes to achieve normocalcemia, but further studies are required.