title: [The influence of orthostatic test on changes of the heart rate variability observed in aboriginals of Magadan region].
abstract: 255 adolescents, aged 13-17, from the north native minorities underwent an active orthostatic test to study the changes in the heart rate variability accounting for the subjects original vegetative types of the nervous regulation. The analysis of interquartile ranges of the heart rate variability values enabled to find individual peculiarities of regulatory mechanisms of reciprocal relationships between parasympathetic and sympathetic components of the vegetative nervous system. The findings testified that, irrespectively of the age, up to 45% of the examinees had optimal levels of reactivity and balance of the components of the vegetative nervous system. The other reactions covered 4-18%. At the same time, low (paradoxical) or excessive vegetative reactivity could be found in each typified group, but, to a greater extent, it was observed in the sympathetic adolescents. Of note that, the individuals with expressed misbalance of regulatory components were revealed who demonstrated the difference in the heart rate variability indices before and during the active orthostatic test going beyond the ranges of the 10th and 90th percentiles. That can be considered as elevated risks for dysadaptation in those individuals under extra functional exercises.
authors.forename: A N
authors.initials: AN
authors.lastname: Loskutova
authors.forename: A L
authors.initials: AL
authors.lastname: Maksimov
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000502:physiology*; D012800:Siberia; D013564:Sympathetic Nervous System / Q000502:physiology*