Changes in cardiovascular indices and bioelectric activity of the brain in response to cold exposure in young men

The aim was to study changes in cardiovascular indices and electroencephalogram (EEG) characteristics in response to short-term general air cooling of the body in young adults. Methods. The sample consisted of 13 healthy men aged 18-21 years who were permanent residents of the city of Arkhangelsk (Northwest Russia). The spectral power (SP) of EEG rhythms was assessed using an electroencephalograph (Neurosoft, Russia). Heart rate variability (HRV) was measured using Varikard equipment (Ramena, Russia). Temperature of the skin surface was measured with an electronic infrared thermometer B Well WF - 1000 (Switzerland). Blood pressure were recorded with an automatic tonometer A&D Medical UA-668 (Japan). All indicators were measured prior to the exposure, under cold exposure in the cold chamber "USF-25N" (-20C, 10 minutes) and 5 and 10 minutes after the exposure. Results. Two types of changes in the study parameters were identified. In type I reaction there was is a greater decrease in body surface temperature, an increase in blood pressure (BP), HRV indicators (RMSSD, pNN50%, TP) and minimal changes in the bioelectrical activity of the brain during the exposure. During the recovery period, systolic BP did not decrease and HRV indicators recovered slowly. In type II reaction, there was a smaller decrease in body surface temperature, an increase in the а-0 activity of the EEG in the anterotemporal regions of the brain and an increase in the 0-activity of the EEG in the frontal regions on the right combined with a increase in HRV (SDNN, pNN50%, RMSSD, TP), an increase in BP during exposure with return to initial values after the exposure. Conclusions. We identified two types of reactions to cold exposure in young men that may reflect the heterogeneity of adaptive reactions of the body's regulatory systems to cold.

cold, EEG, heart rate variability, blood pressure, body surface temperature