Sex-Related Features of Haemodynamic Response to Cold Exposure of the Hand in Young People

Studying the effects of hypothermia on the human body is a pressing issue for modern physiology and practical medicine. The purpose of this article was to establish sex-related features of the haemodynamic response to local cold exposure of the hand in young people. Materials and methods. The research involved apparently healthy young men (n = 27) and women (n = 30) aged 18–20 years, born and permanently living in the Arctic zone of the Russian Federation. The stress test included immersion of the hand in 8 °C water for 1 min. It took 25 min to fully recover after cold exposure. The temperature of 24 °C served as the baseline. Haemodynamic parameters were recorded using SIMONA 111 Integrated Monitoring System (Russia). The following were determined: myocardial contractility indices, heart rate, pulsatility index (a marker of peripheral vascular resistance) as well as integral indicators reflecting the overall level of functional capabilities of the circulatory system. Results. Short-term cold exposure of the hand was found to cause a negative inotropic (decreased myocardial contractility) and a negative chronotropic (decreased heart rate) effects. At the same time, an increase in the body’s functional reserves was detected. The analysis of haemodynamic parameters showed differences in the response of the circulatory system between the examined groups of young men and women. The effect of local cooling of the hand on the cardiovascular system was more pronounced in women than in men. In addition, responses of different groups of haemodynamic parameters were identified: while in men changes occurred primarily due to lowered peripheral vascular resistance and increased blood pressure, in women they were caused by a decrease in contractility indices and myocardial parameters.