AGE FEATURES OF CARDIOVASCULAR SYSTEM FUNCTIONAL PARAMETERS IN ADOLESCENTS LIVING IN DIFFERENT ARCTIC AREAS

Abstract

Age features of autonomic nervous regulation of cardiac activity in 426 healthy adolescents aged 14-17 years living in areas of different latitudes, climatic and ecological conditions of the European North - in the Subpolar (64°30' N) and Polar (67°40' N) areas have been detected. Assessment of the cardiovascular system status was carried out with the use of the heart rate variability (HRV) and blood pressure (BP) parameters. The share of persons with borderline hypertension (BP level exceeded the limit of 90 percentile) also increased with age and reached 63% by the age of 17 years. Among the adolescents living in the Polar region according to the HRV and blood pressure indices, there was registered a significant increase in the proportion of persons with a predominance of sympathetic influences on the heart activity. The greatest adrenergic effects on the cardiovascular system were found in the 15-year-old adolescents of the Polar region, they had higher indices of systolic blood pressure, the heart rate and the regulatory systems stress index, as well as lower total HRV spectrum power in comparison with the 15-year-olds adolescents living in the Subpolar region.