Comparative analysis of indicators of the functional state in contemporary Moscow first-graders and their peers in 2002-2003

Introduction. Medical and biological monitoring studies indicate that in the last decade, there are significant changes in the functional state of children`s and adolescents` organisms. The aim of this work was a comparative study of the functional parameters of children came to study in the primary school (end of September) in 2002-2003 and 2014 in Moscow. Materials and Methods. We used anthropometric data (body height and weight), and the parameters of the cardiovascular system, obtained with spiroarteriocardiorythmographic method: spectral indices of heart rate variability, indicators of cardiac performance, the value of spontaneous arterial baroreflex sensitivity. Results. It is shown that for the evaluated period entry age to school slightly decreased; the data on the length of the body did not change, but indicators of body weight and body mass index increased. At the same time the quantities ща cardiac stroke volume and minute volume of blood circulation at a constant heart rate decreased. Assessment of heart rate variability parameters showed that in 2014 the total spectrum power remained at the 2002-2003-s level, but there was a redistribution of separate power ranges. The research marked an increase in the absolute power of LF and VLF ranges, changes in HF band power didn`t reach the level of statistical significance. The observed increase of LF power range was in relative terms, with a corresponding increase in LF/HF index. The performed both direct and indirect estimate of the sensitivity of spontaneous arterial baroreflex did not reveal the dynamics of this indicator. Conclusions. It is proposed that the increase in absolute and relative power of the LF range at constant power HF range and value of spontaneous arterial baroreflex sensitivity may be due to changes in the functional state of vasomotor regulation - increased sympathetic component in the regulation of the cardiovascular system, which occurred in the body of the first-graders of the evaluated period. Identified changes in the functional state of an organism of first-graders can be interpreted as an adaptive response to the changing conditions of life of today's children.