Impacto do sedentarismo e do histórico familiar de hipertensão na variabilidade da frequência cardíaca, na expressão gênica de citocinas inflamatórias e no estresse oxidativo

Abstract

Systemic arterial hypertension (SAH) affects a significant part of the adult world population and is a risk factor for heart disease and renal dysfunction. According to the data in the literature, offsprings of hypertensive parents have increased blood pressure, serum catecholamine levels, reduced baroreflex sensitivity, and heart rate variability when compared to offspring of normotensive parents. Inflammation and oxidative stress play a key role in the onset of SAH in experimental models. However, evidence of this relationship in the onset of the condition in humans remain sparse. Additionally, several clinical studies have demonstrated an increased number of pro-inflammatory markers in hypertensive patients. The aim of the present study was to assess hemodynamic, autonomic, oxidative stress, and inflammation parameters of sedentary and physically active individuals with either positive or negative family history of hypertension. Participants were made into a group of 83 individuals, all of them male, divided into 4 groups: sedentary individuals born to normotensive parents (FNS n = 21) and sedentary children of hypertensive parents (FHS n = 19), physically active individuals born to normotensive parents (FNA n = 19) and physically active children of hypertensive parents (FHA n = 24). We measured body composition, blood pressure, HR variability, and blood was collected for biochemical and molecular analysis. Assessment of oxidative stress and inflammatory mediators were performed by the collection of blood samples. The samples were used to evaluate the gene expression of the inflammatory cytokines TNF-α, il-1β, il-6 and il-10. For that, we obtained the total RNA using the Tempus Isolation Kit, the cDNA using the High Capacity cDNA Reverse Transcription Kit, and then the quantitative PCR reaction was then performed. The partial findings of the present study show that sedentary individuals born to hypertensive parents, despite not having higher blood pressure levels (the FHS group) presented higher values of LF / HF when compared to the physically active groups (3.3 ± 0.5 vs. FNA: 1.7 ± 0.3 and fha: 1.8 ± 0.3 ms) and lower than RMSSD (25.5 ± 10.0 vs FNA: 39.4 ± 22.3 ms). In addition, the fhs group had higher nadph oxidase activity (0.15 ± 0.02 vs. FNA: 0.09 ± 0.01 µmol/min/mg of protein) and higher values of TNF-alpha (56.68 ± 7.16 vs FNA: 24.40 ± 2.06 and FHA: 29.26 ± 3.42 pg/ml). Therefore, our findings suggest an association between a positive history of hypertension and sedentary lifestyle with the activation of the inflammatory system and negative changes in cardiac autonomic modulation. We conclude that is has to be associated with increased oxidative stress.