O efeito agudo do exercício físico na concentração plasmática de óxido nítrico e no valor da pressão arterial em idosos com diferentes níveis de condicionamento físico: a influência dos polimorfismos do gene da sintase do óxido nítrico endotelial.
Carregando...
Arquivos
Data
2019-12-16
Autores
Reia, Thaís Amanda
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Concomitantemente ao crescente número de idosos tem se observado o aumento de problemas de saúde, entre os quais, a hipertensão arterial (HA) se destaca como doença de maior prevalência na população idosa. Considerando que a variação genética tem alta influência sobre o desenvolvimento da HA, pesquisas vem sendo desenvolvidas com o objetivo de identificar os genes que participam de sua etiologia. Partindo desse pressuposto, alguns polimorfismos são estudados, dentre eles, os polimorfismos do gene da Sintase do Óxido Nítrico Endotelial (eNOS). Embora a maioria dos estudos demonstre os benefícios decorrentes da prática regular de exercícios físicos para contrapor os efeitos deletérios dos polimorfismos do gene da eNOS, bem como a produção de Óxido Nítrico (NO) e controle da pressão arterial (PA), ainda é pouco esclarecido o efeito agudo do exercício físico sobre tais variáveis. Desse modo, o objetivo deste estudo foi analisar o efeito agudo do exercício físico na concentração de NO e nos valores de PA em idosos com diferentes níveis de condicionamento físico (CF) e, também, verificar se os polimorfismos do gene da eNOS exercem influência sobre essas respostas. Após passarem pelos critérios de elegibilidade, 145 idosos de ambos os sexos, com idade entre 60 a 80 anos foram submetidos a avaliações hemodinâmicas, antropométricas, bioquímicas, genéticas e físicas. O protocolo de intervenção foi composto por uma caminhada de 40 min (40-60% VO2máx previamente determinado) realizada em esteira ergométrica, com coletas sanguíneas nos momentos pré e pós-teste, com o objetivo de mensurar a concentração plasmática de nitrito (NO2-), biomarcadores de estresse oxidativo (TBARS) e medidas de PA nos momentos pré e pós-teste. Foi realizada ANOVA de duas vias para medidas repetidas com pós-teste de SIDAK para detectar diferença (p<0,05) entre os grupos (G1- condicionamento físico bom; G2- condicionamento físico fraco) e os momentos (pré e pós-caminhada). Posteriormente, foi feita análise de regressão linear multivariada para verificar a influência dos polimorfismos do gene da eNOS sobre as respostas de NO2- e PA. Não houve diferença significativa para os valores de NO2- e PAD em nenhum momento para ambos os grupos. Já para os valores de TBARS, o G2 apresentou um aumento significativo pós-exercício físico (p=0,008). Houve um aumento significativo na PAS pós-exercício físico para os dois grupos (p<0,001). O G2 apresentou maior valor de PAS no momento pós-exercício físico (p=0,038). Os polimorfismos 894G>T e o intron 4 b/a não apresentaram influência sobre as respostas de NO2-, TBARS e PA, entretanto, o polimorfismo -786T>C apresentou influência significativa apenas para PA. O genótipo homozigoto (TT) apresentou associação inversa sobre os valores de PAS e PAD, enquanto o heterozigoto (TC) apresentou associação positiva para PAD. Maior nível de CF também apresentou influência para menor valor de PA. Destaca-se a importância de se adotar um estilo de vida ativo, visto que os idosos com bons níveis de CF tiveram menores valores de PA e estresse oxidativo imediatamente após a sessão de exercício físico, concluindo que a manutenção de bons níveis de CF pode ter um efeito protetor para riscos cardiovasculares.
Concomitantly with the increasing number of elderly people, it has been observed an increase of health problems, such as hypertension (HA) which stands out as the most prevalent disease in older population. Genetic variation has been associated with a high influence on development of HA, and scientific research has been developed with the objective to identify the genes that participate in its etiology. Based on this background, some polymorphisms are studied, such as the polymorphisms of Endothelial Nitric Oxide Synthase gene (eNOS). Although most studies point to the benefits of regular physical exercise to counteract the deleterious effects of the polymorphisms of eNOS gene, as well as nitric oxide (NO) production and blood pressure control (BP), the effect of acute exercise is still poorly understood. Thus, the purpose of this study was analyze the acute effect of physical exercise on NO concentration and BP values in elderly with different level of training status (TS) and also verify the influence of polymorphisms of eNOS gene on these variables. After passing the ellegibility criteria, 145 elderly men and women, aged 60 to 80 years old, underwent hemodynamic, anthropometric, biochemical, genetic and physical evaluations. The intervention protocol consisted of a 40 min walk (40-60% previously determined VO2max) performed on a treadmill, with blood collections at the pre and post-test moments, with the objective of measuring nitrite plasma (NO2-), oxidative stress biomarkers (TBARS) and BP measurements at the pre and post-test moments. ANOVA Two-way was performed for repeated measures with pos hoc test SIDAK to control the difference (p <0.05) between groups (G1 - good TS; G2 - poor TS) and the moments (pre and post-exercise). Subsequently, a linear multivariate analysis was constructed to verify the influence of polymorphisms eNOS gene polymorphisms on NO2- and PA responses. There was no significant difference for NO2- and DBP values at any time for both groups. As for TBARS values, G2 showed significant increase after physical exercise (p = 0.008). There were significant increase in SBP after exercise for both groups (p <0.001). And G2 presented higher SBP value after exercise (p = 0.038). Polymorphisms 894G>T e o intron 4 b/a had no influence on NO2- and BP responses. However, the -786T> C polymorphism had a significant influence on BP. The homozygous genotype (TT) showed an inverse association with SBP and DBP values, while the heterozygote (TC) showed a positive association for DBP. Higher TS level also influenced lower BP. The importance of an active lifestyle is emphasized, since the elderly with good TS levels had lower BP values and oxidative stress immediately after the exercise session, concluding that the maintenance of good TS levels may have a protective effect for cardiovascular risks.
Concomitantly with the increasing number of elderly people, it has been observed an increase of health problems, such as hypertension (HA) which stands out as the most prevalent disease in older population. Genetic variation has been associated with a high influence on development of HA, and scientific research has been developed with the objective to identify the genes that participate in its etiology. Based on this background, some polymorphisms are studied, such as the polymorphisms of Endothelial Nitric Oxide Synthase gene (eNOS). Although most studies point to the benefits of regular physical exercise to counteract the deleterious effects of the polymorphisms of eNOS gene, as well as nitric oxide (NO) production and blood pressure control (BP), the effect of acute exercise is still poorly understood. Thus, the purpose of this study was analyze the acute effect of physical exercise on NO concentration and BP values in elderly with different level of training status (TS) and also verify the influence of polymorphisms of eNOS gene on these variables. After passing the ellegibility criteria, 145 elderly men and women, aged 60 to 80 years old, underwent hemodynamic, anthropometric, biochemical, genetic and physical evaluations. The intervention protocol consisted of a 40 min walk (40-60% previously determined VO2max) performed on a treadmill, with blood collections at the pre and post-test moments, with the objective of measuring nitrite plasma (NO2-), oxidative stress biomarkers (TBARS) and BP measurements at the pre and post-test moments. ANOVA Two-way was performed for repeated measures with pos hoc test SIDAK to control the difference (p <0.05) between groups (G1 - good TS; G2 - poor TS) and the moments (pre and post-exercise). Subsequently, a linear multivariate analysis was constructed to verify the influence of polymorphisms eNOS gene polymorphisms on NO2- and PA responses. There was no significant difference for NO2- and DBP values at any time for both groups. As for TBARS values, G2 showed significant increase after physical exercise (p = 0.008). There were significant increase in SBP after exercise for both groups (p <0.001). And G2 presented higher SBP value after exercise (p = 0.038). Polymorphisms 894G>T e o intron 4 b/a had no influence on NO2- and BP responses. However, the -786T> C polymorphism had a significant influence on BP. The homozygous genotype (TT) showed an inverse association with SBP and DBP values, while the heterozygote (TC) showed a positive association for DBP. Higher TS level also influenced lower BP. The importance of an active lifestyle is emphasized, since the elderly with good TS levels had lower BP values and oxidative stress immediately after the exercise session, concluding that the maintenance of good TS levels may have a protective effect for cardiovascular risks.
Descrição
Palavras-chave
Envelhecimento, Hipertensão arterial, Polimorfismos da eNOS, Exercício físico agudo, Óxido nítrico, Aging, Hypertension, eNOS polymorphisms, Acute physical exercise, Nitric oxide