Comparative analysis of structural and functional changes in the microcirculatory system in residents of the northeastern and northwestern regions of Russia

Introduction. The aim of the study was a comprehensive assessment of regional differences in the structural and functional organization of the microcirculatory bed and its neurovegetative regulation in residents of northern climatic and geographic regions of the Russian Federation (Magadan and Murmansk) and in residents of central Russia (Ulyanovsk and Moscow). Materials and methods. The study included 299 male subjects aged 17–21 years: 119 residents of the northeastern region of Russia, 72 representatives of the northwestern region, and 108 participants of central Russia. The parameters were assessed when the subjects were at rest in a sitting position. The main indicators of the microcirculation were analyzed with capillaroscopy (Capillaroscan-1), whereas the indicators of the cardiovascular system and heart rate variability were measured using the VARICARD-KARDi software. Results. We revealed significant regional differences in the organization of the microcirculatory bed among residents of the northern regions of Russia, indicating the formation of various physiological strategies for adaptation to chronic cold exposure. The patients from the northeastern region showed signs of an isolation-related metabolic adaptation, which manifested in pronounced vasoconstriction (an increase in total peripheral vascular resistance by +15–20% and a tendency to nocturnal restructuring of the microcirculation in general), an increase in basal metabolism (by 10% of the normal values), and predominance of parasympathetic regulation. In contrast, addictive reactions characterized by microvascular dilation, sympathicotonia, and elevated nitric oxide levels prevailed in the residents of the northwestern region. The control group from central Russia demonstrated intermediate indicators. Conclusion. There are regional differences in the organization of the microcirculatory bed, autonomic regulation, and hemodynamics among residents of the northwestern and northeastern regions of Russia indicative of different adaptive strategies to cold exposure. The northeastern population predominantly exhibits an adaptation pattern of an isolation-induced metabolic type, whereas the northwestern population demonstrates a tendency toward a habituation response, indicating a diverse range of physiological adaptations to chronic cold exposure conditions. Keywords: microcirculation, heart rate variability, north, Arctic, central Russia