The Level of Markers Stimulating Growth Factor 2 (ST2), N-Terminal Prohormone of Brain Natriuretic Peptide (NT-proBNP), and D-Dimer in Healthy Volunteer Testers in 21-Day Head-Down -6° Tilt Bed Rest as a Model of Hypodynamia

The paper presents an analysis of the proteomic composition in relation to both the risk of thrombosis and changes in the state of cardiomyocytes associated with the risk of cardiac fibrosis and heart failure. We examined 12 practically healthy male volunteers exposed to head-down -6° tilt bed rest (HDBR) for 21 days. The revealed decrease in the level of stimulating growth factor 2 (ST2) on days 10 and 21 relative to the initial values (background; 5 days before HDBR) indicated a decrease in the myocardial load and cardiomyocyte extensibility. The level of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) increased on day 2, decreased on days 10 and 21 of HDBR relative to the background levels, and returned to baseline values after the recovery period (5 days after HDBR). The revealed changes in the level of NT-proBNP reflected the increase in circulating blood volume corresponding to HDBR duration and the role of the gravity component in increasing the functional load on the myocardium. Unchanged blood level of D-dimer at all points of the study indicates that there is no risk of thrombosis under the conditions of this study.