Impacto do sobrepeso em indivíduos com histórico familiar positivo de hipertensão: avaliações de marcadores autonômicos, de inflamação e estresse oxidativo

Abstract

Considering the high prevalence of hypertension in the world population, the importance of a family history of hypertension and changes in lifestyle wich have been associated with an increase in the prevalence of overweight and obesity, it is necessary to study mechanisms classical and new that could be involved in the genesis of hypertension. In this sense, the objective of the present study was to evaluate cardiovascular, autonomic, inflammatory and oxidative stress parameters in individuals with a family history of hypertension with overweight or eutrophic (FHS group and FHE group, respectively), comparing them with individuals without family history of hypertension, eutrophic or with overweight (FNE group and FNS group, respectively). A cross - sectional analytical study was carried out. A total of 65 male subjects were divided into 4 groups: FHE (n = 13), FHS (n = 20), FNE (n = 13) and FNS (n = 19). The study had 4 experimental phases: Phase 1 - Application of a family history questionnaire and selection of the research subjects; Phase 2 - Assessment of physical activity level, perceived stress, body composition, blood pressure recording and cardiovascular autonomic modulation evaluation; Phase 3 - Blood collection for hematological, biochemical, inflammatory and oxidative stress analysis and evaluation of body composition by bioimpedance; Phase 4 - Analysis of the Variability of Heart Rate and Phase 5 - Analysis of inflammatory mediators, oxidative stress, antioxidants and nitrites. Our results showed a significant increase in sympathetic modulation associated with decreased parasympathetic modulation and a significant increase in cardiac sympatovagal balance (LF / HF) in the groups with a family history of hypertension (LF / HF - FHE: 3.34 ± 0.46 and FHS: 3.07 ± 0.22) when compared to individuals without a family history of hypertension (LF / HF - FNE: 2.24 ± 0.20 and FNS: 2.24 ± 0.82). These were accompanied by an increase in BP in the groups with a history of hypertension (SBP - FHE: 121.5 ± 2 and FHS: 121.1 ± 1.7 mmHg) in relation to the group of eutrophic individuals with no family history of hypertension (SBP - FNE: 111.3 ± 2 mmHg) and metabolic alterations, characterized by increased plasma glucose, triglycerides and VLDL in the FHE and FHS groups in relation to the FNE and FNS groups. Overweight (FNS and FHS groups) was associated with the reduction of α1 and the α1 / α2 ratio (FNS: 1.65 ± 0.08 and FHS: 1.04 ± 0.03 vs. FNE: 1.32 ± 0, 04 and FHE: 1.34 ± 0.05), accompanied by increased activity of NADPH oxidase (FNS: 0.016 ± 0.002 and FHS: 0.020 ± 0.002 vs. FNE: 0.012 ± 0.0005 and FHE: 0.015 ± 0.0008 μM/mg protein) and hydrogen peroxide (FNS: 18.1 ± 3.5 and FHS: 22.1 ± 3.7 vs. FNS: 11.33 ± 0.87 μM H2O2 and FHE: 11.9 ± 0.61 μM H2O2) in relation to the FNE and FHE groups. In addition, cardiac sympathetic modulation was increased in absolute values (FHS: 1928 ± 259.1 vs. FNE: 893.3 ± 99.2, FHE: 1419.4 ± 109.9, FNS: 1247, 7 ± 156.1 ms²) and plasma nitrite (FHS: 0.52 ± 0.11 vs. FNE: 0.15 ± 0.03, FHE: 0.15 ± 0.02 and FNS: 0.24 ± 0.05 μM/mg protein) in the group of overweight offspring of hypertensive parents. We observe a positive correlation (r = 0.42, p = 0.042) between Systolic BP and LF/HF in groups with a positive family history of hypertension (FHE and FHS). In conclusion, our results demonstrate that sedentary young adults with a family history of hypertension and/or overweight present an impairment in HRV, characterized by a more marked increase in cardiac sympathetic modulation markers in SAH children and by reduction of markers of parasympathetic modulation and total variability in overweight individuals, which was accompanied by systemic increase of pro-oxidants and reduction of antioxidants. However, the most important finding of the present study was that the overweight group and family history of SAH, despite not having an additional BP increase or exacerbation of changes in the metabolic profile, presented all the dysfunctions observed in the isolated presence of these risk factors, as well as exacerbation of nitric oxide metabolism and cardiac sympathetic modulation, which may be associated with increased target organ damage and cardiovascular risk in this population.