Resposta hemodinâmica e metabólica ao estresse físico e mental em indivíduos normais: estudo piloto

Abstract

Introduction: There is a direct interaction of the central nervous system and the autonomic nervous system with lipid and glycidic metabolism. Thus, glucose and free fatty acid (FFA) mobilization is greatly influenced by the autonomic nervous system, especially the sympathetic nervous system. FFA exhibit a wide range of functions, from immune regulation to metabolism in a variety of tissues and organs. Fatty acid concentration is increased in stress states, when vasoconstrictor hormones (norepinephrine, adrenaline) will be released and associated hemodynamic changes Objective: To evaluate hemodynamic, autonomic and metabolic changes in response to the association of acute stress (physical and mental) in healthy individuals. Methods In this study, 15 subjects, 31±7 years old, of both sexes, were evaluated 3 times: before and after the application of two test sessions, combining physical (isometric exercise test) and mental (Stroop color test) stress at 30 min intervals. Blood pressure, heart rate, systemic vascular resistance and distensibility of the large and small arteries obtained with HDI were analyzed (Hypertension Diagnosis Incorporation, CR2000, Eagan, USA); heart rate variability parameters recorded with Polar RS800 and analyzed with Kubios software. Blood samples were collected for measurement of fatty acids glucose, insulin and catecholamines. The ANOVA test was used to compare the parameters at the different evaluation moments; Linear regression analysis was used to verify the effect of hemodynamic variables on metabolic changes. The significance of p established was <0.05. Results: Compared to baseline, after the first stimulus there was a significant increase (p <0.05) in diastolic blood pressure (5.1%), peripheral vascular resistance (6.1%), and large distensibility (14%). and small arteries (25%) and FFA levels (24%). These changes were even more evident after the second stimulus. Compared to baseline, noradrenaline values increased significantly after the second stimulus (18,7%). Hemodynamic changes were not directly related to changes in FFA. Conclusion: The organism of healthy young people, when challenged by a combination of physical and mental stress, responds with changes in the sympathetic nervous system, which influence the hemodynamic profile. The metabolic changes that accompany this response, especially the increase in free fatty acid rates, are rapid and proportional to the stimuli applied, and appear to occur independently of the observed hemodynamic changes.