Modulação Autonômica Cardíaca é Fator Chave para Pressão Alta em Adolescentes / Cardiac Autonomic Modulation is a Key Factor for High Blood Pressure in Adolescentes

Resumo Fundamento O interesse pela hipertensão em crianças e adolescentes aumentou desde a atualização do sistema de classificação da pressão arterial para comparar com o sistema de classificação dos adultos, alterando a terminologia de "normal alta" para "pré-hipertensão". Objetivo O objetivo deste estudo foi analisar a associação da modulação autonômica cardíaca com os níveis pressóricos dos adolescentes. Métodos 203 adolescentes foram agrupados de acordo com a pressão arterial sistólica (PAS) e a pressão arterial diastólica (PAD). Um grupo foi caracterizado como pré-hipertensão, e o outro como normotenso. Foram coletadas características antropométricas, cardiovasculares e de qualidade do sono. Inicialmente, os dados foram submetidos ao teste de normalidade Kolmogorov-Smirnov . As variáveis quantitativas contínuas foram analisadas por meio do teste T de Student não pareado. Para análise das variáveis categóricas, foi utilizado o teste qui-quadrado. Um modelo de regressão logística foi realizado. O nível de significância estabelecido foi p<0,05. Os dados foram expressos como média ± desvio padrão e intervalo de confiança. O software R foi utilizado para análise dos dados. O tamanho do efeito foi calculado com a fórmula de Cohen. Resultados O grupo pré-hipertensão apresentou aumento da entropia de Shannon e diminuição da variância total. Além disso, no modelo de regressão logística, os adolescentes deste grupo tiveram 1,03 mais chances de ter a entropia de Shannon afetada quando a PAS foi ajustada ao gênero, maturação sexual, tempo escolar, idade, circunferência da cintura e qualidade do sono. Conclusão Nossos dados mostram que a modulação autonômica pode desempenhar um papel importante no desenvolvimento da pressão arterial elevada em adolescentes ao controlar fatores como tempo escolar e qualidade do sono.

Abstract Background The interest regarding hypertension among children and adolescents has increased since the blood pressure rating system was updated to be compared with the adult rating system, changing the terminology from "normal high" to "prehypertension". Objective This study aimed to analyze the association between cardiac autonomic modulation and pressure levels of adolescents. Methods 203 adolescents were grouped according to systolic blood pressure (SBP) and diastolic blood pressure (DBP). One group was characterized as prehypertension, and the other as normotensive. Anthropometric, cardiovascular and sleep quality characteristics were collected. Initially, the data were submitted to the Kolmogorov-Smirnov normality test. Continuous quantitative variables were analyzed using the unpaired Student t-test. For the analysis of categorical variables, a chi-square test was used. A logistic regression model was performed. The level of significance was set at p<0.05. The data were expressed as mean ± standard deviation and confidence interval. The R software was used for data analysis. The effect size was calculated using the Cohen's formula. Results The prehypertension group showed an increase in Shannon entropy and a decrease in total variance. Also, in the logistic regression model, adolescents in this group were 1.03 times more likely to have Shannon entropy's affected when SBP was adjusted for gender, sexual maturation, school time, age, waist circumference, and sleep quality. Conclusion Our data show that autonomic modulation may play an important role in the development of elevated blood pressure in adolescents, when controlling for other factors, such as school time and sleep quality.

Influence of Family History of Diabetes on Cardiac Autonomic Dysfunction of Adolescents

Abstract Background To evaluate cardiac autonomic modulation of adolescents with a family history of diabetic parents. Objective This study aims to evaluate the influence of a family history of diabetes on cardiac autonomic modulation. Methods This is an analytical and cross-sectional study on adolescents between 11 and 18 years of age, of both genders, who were divided into group with a family history of diabetes and a control group without a family history of diabetes. The study protocol consisted of the analysis of heart rate variability, blood pressure, anthropometric measurements, and body composition. Also, by using questionnaires, level of physical activity, sexual maturation, and sleep quality were evaluated. Normality of data distribution was tested using the Kolmogorov-Smirnov test. Then, statistical significance was evaluated using the Student's t-test, and the Cohen's teste was used for calculation of the effect size. The level of significance adopted in the statistical analysis was 5%. Results When the group of individuals with a family history of diabetes was compared with the control group, statistically significant differences were observed in the variables the standard deviation of the NN time series interval (SDNN) (43.9 ± 2.2 vs. 53.5 ± 2.6 ms), the square root of the quadratic differences (RMSSD) (41.9 ± 3.3 vs. 52.4 ± 3.2 ms), standard deviation of beat-to-beat instantaneous variability (SD1) (29.7 ± 2.3 vs. 37.1 ± 2.3 ms), long-term standard deviation of continuous RR intervals (SD2) (. 54.1 ± 2.6 vs. 66.66 ± 3.5 ms), and in low frequency (LF) (496.0 ± 49.5 vs. 728 ± 71.6 ms2) and high frequency (HF) (1050.0 ± 120.4 vs. 737.4 ± 98.5 ms2) in the frequency domain. Conclusions Global autonomic modulation is decreased in adolescents with a family history of diabetes. We also observed a decrease in vagal activity in this group. So, sympathetic autonomic modulation is predominant in this population. (Int J Cardiovasc Sci. 2020; [online].ahead print, PP.0-0)

Estimated intensity and acute cardiovascular response to a single exercise session guided by the fitness app Sworkit® Personal Trainer

Aim: The aim of the present study was to evaluate the effect of an exercise session prescribed by the Sworkit® Personal Trainer application on hemodynamic and autonomic responses. Methods: The sample consisted of 11 men classified as sedentary according to IPAQ. The exercises were randomly selected by the app Sworkit® Personal Trainer, using the pre-built program "Light Warm-Up Cardio" (see supplementary material). Heart rate and perceived exertion data were collected every minute during an exercise session. Blood pressure and heart rate variability were measured Pre, Post, 30 min, 12h, 24 h, and 48h after exercise. Heart rate and rate of perceived exertion were collected during the 30 minutes exercise. Results: Hemodynamic responses showed differences in heart rate and systolic blood pressure: Post, 12 h and 24 h compared to Pre. We also found significant statistical differences in the heart rate variability indexes when comparing Post, 30min to 48h versus Pre, indicating modifications in the autonomic modulation post-exercise. The perceived exertions scale remained between 13-14 during the exercise. Heart rate was 149 ± 5.26 (80 ± 5% of HRmax) during the 30min exercise, indicating a moderate to vigorous intensity. Conclusion: We concluded that a single exercise session guided by the Sworkit® Personal Trainer application could generate autonomic changes in up to 12 hours, presenting a moderate to vigorous intensity in 30 minutes of exercise for sedentary men.(AU)