Histórico familiar de hipertensão e nível de atividade física sobre o sistema nervoso autônomo de adolescentes

Abstract

ABSTRACT Introduction: Systemic Arterial Hypertension (SAH) is a chronic degenerative disease and multiple causes. An important risk factor for this disease is the sedentary lifestyle, which is present in many times since adolescence. This disease is associated with autonomic alterations such as increased sympathetic modulation and reduced vagal modulation. Studies also point out that the family history of this disease has a great influence on the physiological responses of individuals. Objective: To analyze the level of physical activity and family history of SAH in relation to the behavior of the autonomic nervous system of adolescents. Materials and methods: 162 adolescents from the public school system, aged 11 to 18 years, were divided into offspring of Normotensive (ON, n = 126) and offspring of Hypertensive (OH, n = 36). After the signing of the Term of Consent by the parents and the Consent Term by the parents, the adolescents were submitted to the Anthropometric Assessment, Physical Activity Level through the IPAQ questionnaire, Sexual Maturation by the Tanner Board, Sleep Quality Index by the Pittsburgh questionnaire and the Heart Rate Variability using the Electrocardiogram. Results: It was observed that the two ON and OH groups did not have significant differences in the main variables that characterize both groups, such as systolic and diastolic blood pressure (p = 0.31 / p = 0.07), Sleep Quality Index (p = 0.57), Waist Circumference (p = 0.44) and Fat percentage (p = 0.33). This shows a homogeneity between groups. In the autonomic variables, statistically different differences were observed regarding RMSSD, pNN50, Total Variance, HF and SD1, all with p <0.05. There was a reduction of these indices in the OH group, where they all represent a vagal withdrawal. When analyzing the level of physical activity between the groups, the LF variable presented a significant difference (p = 0.03) being higher in the ON low level of physical activity group, indicating a sympathetic increase. It should be noted that in many variables, the Effect Size showed very high clinical relevance (ES> 0.8). Conclusion: Research has shown that since adolescence, autonomic dysfunction is already present, even without signs of high blood pressure or any other symptom of easier and more common verification and diagnosis.