STRESS BEFORE EXAMS AS A RISK FACTOR CAUSING FUNCTIONAL DISORDERS IN THE CARDIOVASCULAR SYSTEM IN STUDENTS WITH DIFFERENT METABOLIC STATUS
Students who attend a medical HEE often face strain in their adaptation mechanisms when preparing for exams; it can create substantial preconditions for functional deregulation in body systems. The articles outlines some results obtained via examining heart rate variability (HRV) in students of the 2nd and the 3<sup>rd</sup> year attending the North Ossetia State Medical Academy who had different metabolic status in a period prior to exams. Our research goal was to assess the state of the vegetative nervous system and regulatory systems in students with different metabolic status (BMI< 25; BMI=25-29.99; BMI=30-34.99.) who had to face excess stress during preparation to exams. Heart rate intervals were registered during five minutes in an examined person being at rest. HRV parameters were analyzed in time and frequency domains. We revealed that medical students had elevated activity of the sympathetic section in their vegetative nervous system (VNS) during a period prior to exams; in particular, it was apparent for the regulation system of the vasomotor center (PLF = 48.4 %). Students' bodies had apparent strain in their regulatory systems (SI=177.5 a.u.). Total activity of the regulatory system was significantly elevated (TP=2,293 msec<sup>2</sup>) due to central regulation levels. As students' BMI grew, there was a decrease in activity of the parasympathetic component in vegetative regulation and heart rate management became more centralized (IC=3.2-4.5 a.u.). Students with Class 3 obesity had the maximum spectrum power of the superlow component in heart rate variability (PVLF=29.3 %). HRV parameters analysis allows estimating whether adaptation processes in students' bodies are adequate during preparation to exams; it can be done in screening mode and provides an opportunity to perform timely prevention activities.