Potentially Atherogenic Combined Biochemical and Physiological Changes in Human Antiorthostatic Hypokinesia

We analyzed the relation between the blood content of modified low-density lipoproteins (mLDL), total hemolytic complement activity (TACS), and heart function parameters in patients with 21-day antiorthostatic hypokinesia. Healthy male volunteers were subjected to 6° head-down bedrest for 21 days. TACS and mLDL were measured in the blood serum. Heart rate variability parameters were calculated from the data obtained using a SACR device in the supine position during free breathing and in two breathing tests (mask test and controlled breathing). The use of the mask test revealed a direct correlation between the level of TACS and the low-frequency component of the heart rhythm and an inverse correlation between end-systolic volume and blood content of mLDL on day 21. The use of breathing tests enhances the correlation between end-systolic volume and mLDL content. Diastolic BP measured during free breathing (without mask) on day 21 positively correlated with mLDL content, and this correlation increased under conditions of functional tests. The correlations between the content of substances associated with the development of atherosclerosis against the background of adaptive inflammatory processes and functional restructuring of the cardiovascular system demonstrate a dynamic state in the human body, which will lead to the development of pathology, in case of sanogenetic mechanisms are insufficient.