História Familiar de Hipertensão Prejudica o Balanço Autonômico, mas não a Função Endotelial em Jovens Jogadores de Futebol / Family History of Hypertension Impairs the Autonomic Balance, but not the Endothelial Function, in Young Soccer Players

Resumo Fundamento A história familiar de hipertensão (HFH) é um fator de risco consistente para diversas doenças crônicas que são acompanhadas por hipertensão. Além disso, a variabilidade da frequência cardíaca (VFC) e a vasodilatação mediada pelo fluxo (VMF), ambas relacionadas ao consumo máximo de oxigênio (VO2max), são geralmente prejudicadas durante a hipertensão. Objetivo Comparar a modulação autonômica, a função endotelial (FE) e o consumo máximo de oxigênio (VO2max) de jovens atletas, separados de acordo com a história de pressão arterial (PA) dos seus pais, a fim de investigar a influência da ascendência genética nesses parâmetros. Métodos Quarenta e seis jovens jogadores de futebol do sexo masculino (18±2 anos) foram divididos em quatro grupos: 1- pai e mãe normotensos (FM-N); 2- apenas pai hipertenso (F-H); 3- apenas mãe hipertensa (M-H); 4- pai e mãe hipertensos (FM-H). Foram realizadas medições da PA, VMF, VFC e do VO2max. Na análise estatística, foi adotado o nível de significância de 5%. Resultados O desvio padrão dos intervalos RR normais (SDNN; FM-N=314±185; FM-H=182,4± 57,8), a raiz quadrada das médias quadráticas das diferenças dos intervalos R-R sucessivos (RMSSD; FM-N=248±134; FM-H=87±51), o número de diferenças entre intervalos NN sucessivos maiores que 50 ms (NN50; FM-N=367±83,4; FM-H=229±55), a proporção de NN50 dividida pelo número total de NNs (pNN50; FM-N=32,4±6,2; FM-H=21,1±5,3) e os componentes de alta (HF; FM-N=49±8,9; FM-H=35,3±12) e baixa frequência (LF; FM-N=50,9±8,9; FM-H=64,6±12), em unidades normalizadas (%), foram significativamente mais baixos no grupo FM-H do que no grupo FM-N (p<0,05). Por outro lado, a relação LF/HF (ms2) foi significativamente maior (p<0,05). Não foram encontradas diferenças significativas no VO2max e na VMF entre os grupos (p<0,05). Conclusão Em jovens jogadores de futebol do sexo masculino, a HFH desempenha um papel potencialmente importante no comprometimento do balanço autonômico, principalmente quando ambos os pais são hipertensos, mas não apresentam alterações no VO2max e na VMF. Nesse caso, há uma diminuição no controle simpatovagal, que parece preceder o dano endotelial. (Arq Bras Cardiol. 2020; 115(1):52-58)

Abstract Background The family history of hypertension (FHH) imposes consistent risk for diverse chronic diseases that are accompanied by hypertension. Furthermore, the heart rate variability (HRV) and flow-mediated dilation (FMD) are both related to maximal oxygen uptake (VO2max), and are usually impaired during hypertension Objective To compare the autonomic modulation, the endothelial function (EF) and maximum oxygen uptake (VO2max) of young athletes, separated according to their parents' blood pressure (BP) history, in order to study the influence of their genetic background on those parameters. Methods A total of 46 young male soccer players (18±2 years of age) were divided into four groups: 1-normotensive father and mother (FM-N); 2-only father was hypertensive (F-H); 3-only mother was hypertensive (M-H); 4-father and mother were hypertensive (FM-H). Measurements of BP, FMD, HRV and VO2maxwere performed. The significance level adopted in the statistical analysis was 5%. Results The standard deviation of normal RR intervals (SDNN; FM-N=314±185; FM-H=182.4± 57.8), the square root of the mean squared differences in successive RR intervals (RMSSD; FM-N=248±134; FM-H=87±51), the number of interval differences of successive NN intervals greater than 50ms (NN50; FM-N=367±83.4; FM-H=229±55), the ratio derived by dividing NN50 by the total number of NN intervals (pNN50; FM-N=32.4±6.2; FM-H=21.1±5.3) and the high (HF; FM-N=49±8.9; FM-H=35.3±12) and low-frequency (LF; FM-N=50.9±8.9; FM-H=64.6±12) components, in normalized units (%), were significantly lower in the FM-H group than in the FM-N group (p<0.05). On the other hand, the LF/HF ratio (ms2) was significantly higher (p<0.05). We found no significant difference between the groups in VO2maxand FMD (p<0.05). Conclusions In young male soccer players, the FHH plays a potentially role in autonomic balance impairment, especially when both parents are hypertensive, but present no changes in VO2maxand FMD. In this case, there is a decrease in the sympathetic-vagal control, which seems to precede the endothelial damage (Arq Bras Cardiol. 2020; 115(1):52-58)

Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

Introduction: The purpose of this study was to investigate the effects of isolated vitamin B6 (VB6 ) supplementation on experimental hyperhomocysteinemia (Hhe) induced by homocysteine thiolactone (HcyT). Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB6, HcyT, and HB6 ). On the 30th day of treatment, two groups were supplemented with VB6 in the drinking water (groups: CB6 and HB6 ). After 60 days of treatment, homocysteine (Hcy), cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2)-like 2 (NRF2) and glutathione S-transferase (GST) immunocontent, and superoxide dismutase (SOD), catalase (CAT), and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62%) in relation to the CB6 group. Additionally, GST immunocontent was enhanced (51%) in the HB6 group compared to the HcyT group. Also, SOD activity was lower (17%) in the HB6 group compared to the CB6 group, and CAT activity was higher in the HcyT group (53%) compared to the CB6 group. Ejection fraction (EF) was improved in the HB6 group compared to the HcyT group. E/A ratio was enhanced in the HB6 group compared to the CB6 group. Correlations were found between CAT activity with myocardial performance index (MPI) (r = 0.71; P = 0.06) and E/A ratio (r = 0.6; P = 0.01), and between EF and GST activity (r = 0.62; P = 0.02). Conclusions: These findings indicate that isolated VB6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters (AU)

A single dose of dark chocolate increases parasympathetic modulation and heart rate variability in healthy subjects / Uma única dose de chocolate amargo aumenta a modulação parassimpática e a variabilidade da frequência cardíaca em indivíduos saudáveis

ABSTRACT Objective: The aim of this study was to investigate the acute effect of a single dose of dark chocolate (70% cocoa) on blood pressure and heart rate variability. Methods: Thirty-one healthy subjects (aged 18-25 years; both sexes) were divided into two groups: 10 subjects in the white chocolate (7.4 g) group and 21 in the dark chocolate (10 g) group; measurements were performed at the university's physiology lab. An electrocardiogram measured the sympathovagal balance by spectral and symbolic analysis. Results: A single dose of dark chocolate significantly reduced systolic blood pressure and heart rate. After consuming 10 g of dark chocolate, significant increases were observed for heart rate variability, standard deviation of RR intervals standard deviation of all NN intervals, square root of the mean squared differences between adjacent normal RR intervals root mean square of successive differences, and an increase in the high frequency component in absolute values, representing the parasympathetic modulation. Conclusion: In conclusion the importance of our results lies in the magnitude of the response provoked by a single dose of cocoa. Just 10 g of cocoa triggered a significant increase in parasympathetic modulation and heart rate variability. These combined effects can potentially increase life expectancy because a reduction in heart rate variability is associated with several cardiovascular diseases and higher mortality.

RESUMO Objetivo: O objetivo deste estudo foi investigar o efeito agudo de uma única dose de chocolate amargo (70% cacau) sobre a pressão arterial e a variabilidade da frequência cardíaca. Métodos: Trinta e um indivíduos saudáveis (com idade entre 18-25 anos; ambos os sexos) foram divididos em dois grupos: 10 indivíduos no grupo chocolate branco (7,4 g) e 21 no grupo chocolate amargo (10,0 g); as avaliações foram realizadas no laboratório de fisiologia da Universidade Federal de Ciências da Saúde de Porto Alegre. Resultados: O eletrocardiograma foi realizado para analisar o balanço simpatovagal através da análise espectral e simbólica. Uma única dose de chocolate amargo reduziu significativamente a pressão arterial sistólica e a frequência cardíaca. Depois de consumir 10 g de chocolate amargo, observou-se aumento significativo na variabilidade da frequência cardíaca, o desvio padrão dos intervalos, a raiz quadrada da média do quadrado das diferenças entre os intervalos RR normais adjacentes a raiz quadrada da média da soma dos quadrados das diferenças entre os intervalos NN normais adjacentes e um aumento na componente de alta frequência em valores absolutos, o que representa a modulação parassimpática. Conclusão: Em conclusão, a importância dos resultados aqui apresentados reside na magnitude da resposta provocada por uma dose única de cacau (10 g). Esta provocou um aumento significativo da modulação parassimpática e da variabilidade da frequência cardíaca no coração. Esses efeitos, quando combinados, podem, potencialmente, aumentar a esperança de vida, porque a redução da variabilidade da frequência cardíaca está associada a doenças cardiovasculares e maior mortalidade.

Renal oxygen content is increased in healthy subjects after angiotensin-converting enzyme inhibition

OBJECTIVE: The association between renal hypoxia and the development of renal injury is well established. However, no adequate method currently exists to non-invasively measure functional changes in renal oxygenation in normal and injured patients. METHOD: R2* quantification was performed using renal blood oxygen level-dependent properties. Five healthy normotensive women (50±5.3 years) underwent magnetic resonance imaging in a 1.5T Signa Excite HDx scanner (GE Healthcare, Waukesha, WI). A multiple fast gradient-echo sequence was used to acquire R2*/T2* images (sixteen echoes from 2.1 ms/slice to 49.6 ms/slice in a single breath hold per location). The images were post-processed to generate R2* maps for quantification. Data were recorded before and at 30 minutes after the oral administration of an angiotensin II-converting enzyme inhibitor (captopril, 25 mg). The results were compared using an ANOVA for repeated measurements (mean + standard deviation) followed by the Tukey test. ClinicalTrials.gov: NCT01545479. RESULTS: A significant difference (p<0.001) in renal oxygenation (R2*) was observed in the cortex and medulla before and after captopril administration: right kidney, cortex = 11.08 ± 0.56ms, medulla = 17.21 ± 1.47ms and cortex = 10.30 ± 0.44ms, medulla = 16.06 ± 1.74ms, respectively; and left kidney, cortex= 11.79 ± 1.85ms, medulla = 17.03 ± 0.88ms and cortex = 10.89 ± 0.91ms, medulla = 16.43 ± 1.49ms, respectively. CONCLUSIONS: This result suggests that the technique efficiently measured alterations in renal blood oxygenation after angiotensin II-converting enzyme inhibition and that it may provide a new strategy for identifying the early stages of renal disease and perhaps new therapeutic targets.

Gênero e manifestação de stress em hipertensos / Gender and the manifestation of stess in patients hypertensive

Embora estudos sustentem maior vulnerabilidade ao stress na população feminina, há escassez de dados sobre a população de hipertensos. Realizou-se um estudo transversal para verificar a diferença na prevalência de sintomas de stress entre os gêneros, por meio da aplicação do Inventário de Sintomas de Stress de Lipp e de um questionário de dados sociodemográficos. Os resultados não mostram diferença estatisticamente significativa concernente à presença de sintomas de stress entre as amostras masculina (n=33) e feminina (n=70). Contudo, mais homens apresentaram escores na fase de resistência (60,6 por cento), enquanto a fase de quase-exaustão preponderou entre as mulheres: 41,4 por cento versus 15,2 por cento dos homens. Considerando sintomas físicos e psicológicos no geral, independente de predominância de fase, as mulheres relataram ter significativamente mais sintomas psicológicos de stress nos escores referentes às fases de resistência, quase-exaustão e à fase de exaustão (p<0,05). Esses achados podem auxiliar no planejamento de abordagens de controle de stress.

Even though studies support the idea of greater vulnerability to stress in the female population, there is a dearth of studies related to hypertensive patients. A cross-sectional study was conducted with the aim of verifying the difference in the prevalence of stress symptoms in a male and female sample of hypertensive patients, using Lipp's Adult Stress Symptoms Inventory and a socio-demographic questionnaire. There was no statistically significant difference in respect of the presence of stress symptoms between males (n=33) and females (n=70). However, men obtained higher scores in the resistance phase (60.6 percent), while women obtained higher scores in the near-exhaustion phase (41.4 percent versus 15.2 percent of men). Considering overall physical and psychological symptoms, irrespective of the predominant phase, women reported significantly higher psychological stress symptoms than men in terms of the scores in the resistance and near-exhaustion phases, as well as the scores in the exhaustion phase (p<0.05). These findings may help in the planning of stress-management strategies.