Indicators of pathogenetic pathways causing blood pressure rise upon exposure to extreme ambient temperatures to predict health risks (literature review)

Extreme temperature events (heat and cold waves) are becoming more frequent, intensive and prolonged acting as a risk factor for development and exacerbation of cardiovascular diseases (CVDs). Elevated blood pressure (BP) is one of the main effects produced by temperature exposures on likelihood of adverse cardiovascular events creating elevated health risks. Health risk prediction and development of prevention systems for susceptible population groups require establishing pathogenetic pathways of BP rise upon exposure to extreme ambient temperature and indicators of their activation. Initially, 287 publications were found in eLIBRARY, CyberLeninka, PubMed, Google Scholar databases; of them, 59 were included in this review, their focus being on effects produced by extreme ambient temperatures on BP rise. This review has revealed that pathogenetic pathways responsible for health risks caused by BP rise upon exposure to heat waves initially involve developing vasodilatation and hypovolemia, which laterinduced compensatory activation of the sympathoadrenal system (SAS). Developing tachycardia and hyperdynamic circulation with background hemoconcentration and endothelial dysfunction induce a vasospasm, growing total peripheral vascular resistance (TPR) and, consequently, BP rise. Upon exposure to cold waves and developing hypothermia, SAS activation causes growing TPR with background vasoconstriction and endothelial dysfunction, growing cardiac output due to stimulation of the chrono- and inotropic myocardium function as well as growing blood viscosity due to developing hemoconcentration. We established several indicators of activated pathways able to cause BP rise upon exposure to extreme ambient temperatures: functional ones including skin temperature and heart rate (HR); clinical and laboratory indicators including levels of nitrogen oxide (NO), endothelin-1 (ET-1), catecholamines and hematocrit in blood. These indicators can be used for predicting health risks caused by CVDs based on pre-nosologic changes upon exposure to heat and cold waves. This will help improve preventive measures including those developed for susceptible population groups.