Variabilidade da frequência cardíaca e estresse oxidativo em indivíduos com histórico familiar positivo de hipertensão: impacto do estilo de vida fisicamente ativo

Abstract

The systemic arterial hypertension is a multifactorial syndrome with high prevalence, which is caused by congenital or acquired factors. Data in the literature has been showed that young offspring of hypertensive parents present increased arterial pressure (AP), serum catecholamine levelsand reduced heart rate variability (HRV) when compared to offspring of normotensive parents. It is well known the importance of the active lifestyle in the prevention of a number of diseases; however, there are still few reports in this population. Therefore, the aim of the Study 1 was to evaluate hemodynamic and autonomic parameters in individuals with negative or positive familial history of hypertension sedentary or strength trained. Fourty four adult male subjects were included in this study. They were divided into four groups: sedentary offspring of hypertensive parents (SOH); sedentary offspring of normotensive parents (SON); physically active offspring of normotensive parents (AON); and physically active offspring of hypertensive parents (AOH). Casual AP was measured by ascultarory method. The RR interval was recorded to HRV analysis. The physically active subjects were only those that had at least 6 months of practice of strength training. At rest, AP were similar between groups. However, total RR interval variance (Var RR) was reduced in SOH group (2998±395 ms²) in relation to SON and AON groups (6089±705 and 6133±316 ms²). Additionally, the SOH group showed an increased sympathetic modulation and sympathovagal balance (SOH: 4.2±0.7 vs. SON: 2.8±0.4 and AON: 2.4±0.1). On the other hand, AOH group presented a normalization of these parameters (6373±226 ms² and 2.9±0.2; Var RR and LF/HF, respectively). Based on these results it was designed the Study 2, which aimed to evaluate the impact of physically active life on hemodynamic, autonomic and oxidative stress parameters in individuals with positive or negative family history of hypertension. The study included 127 adult male subjects that were divided into four groups: SOH (n=28), SON (n=28), AON (n=35) and AOH (n=36). The level of physical activity was classified through the IPAQ. Casual AP was measured by auscultatory method, the RR interval was recorded andblood samples were collected for oxidative stress analysis. The DAP was reduced in physically active groups when compared to sedentary groups. The SOH group showed an decrease in Var RR (AON: 4912±538 vs. SOH: 2232±242 ms2) associated with na increase in LF/HF (SON: 1,.26±0.08 vs. SOH: 2.07±0.19) in relation to SON group. These changes were not observed in AOH group. Additionally, the SHO group showed higher systemic levels of hydrogen peroxide (SOH: 16.68±2.74 µM) when compared to the other groups (SON: 9.14±0.9, AON: 8.95± 0.9 e AOH: 9.60± 1.8 µM). Positive correlations were obtained between cardiac sympatovagal balance and DAP (r= 0.30), hydrogen peroxide levels (r= 0.41) and lipoperoxidation (r= 0.35). Our data showed that sedentary offspring of hypertensive parents showed impairment in the cardiac autonomic modulation, which could be associated with AP increase and higher levels of oxidative stress markers. However, these dysfuctions were attenuated in physically active subjects. Therefore, the results suggest that the life style plays an important role in hypertension prevention in genetically predisposed population.