Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
Am J Cardiol. 2013 Dec 1;112(11):1757-62. doi: 10.1016/j.amjcard.2013.07.040. Epub 2013 Sep 13.
Although cardiovascular (CV) risks have been reported in prehypertension, their link to sympathovagal imbalance (SVI) has not been investigated. In the present study, we have assessed the factors contributing to SVI and the prediction of CV risk by SVI in prehypertensives. Body mass index, CV parameters such as heart rate, systolic blood pressure (BP), diastolic BP, mean arterial pressure, rate-pressure product (RPP), stroke volume, left ventricular ejection time, cardiac output, total peripheral resistance, baroreflex sensitivity recorded by continuous blood pressure variability monitoring using Finapres, autonomic function tests recorded by spectral analysis of heart rate variability (HRV), and heart rate and BP responses to standing, deep breathing, and isometric handgrip, and biochemical parameters such as homeostatic model assessment of insulin resistance, lipid risk factors, inflammatory markers, thyroid profile, and renin and oxidative stress parameters were analyzed in young normotensives (n = 118) and prehypertensives (n = 58). Contribution of CV risks to low-frequency/high-frequency (LF/HF) ratio of HRV, the marker of SVI, was determined by multiple regression analysis, and prediction of SVI to RPP, a known CV risk, was assessed by logisitic regression adjusted for body mass index. BP variability, HRV, and autonomic function test parameters were significantly altered in prehypertensives and these parameters were correlated with LF/HF. Insulin resistance, dyslipidemia, inflammation, and oxidative stress contributed to SVI in prehypertensives. LF/HF and baroreflex sensitivity had significant prediction of RPP in prehypertensives. In conclusion, SVI in young prehypertensives is due to both increased sympathetic and decreased vagal tone. CV risks are linked to SVI and SVI predicts cardiac risk in prehypertensives.
虽然已经有研究报道了高血压前期存在心血管（CV）风险，但交感神经-迷走神经失衡（SVI）与 CV 风险的关系尚未得到研究。在本研究中，我们评估了导致 SVI 的因素，以及 SVI 对高血压前期患者 CV 风险的预测作用。我们分析了体重指数、心血管参数（心率、收缩压（BP）、舒张压、平均动脉压、心率血压乘积（RPP）、心排量、射血时间、心输出量、总外周阻力）、通过 Finapres 连续血压变异性监测记录的压力反射敏感性、通过心率变异性（HRV）频谱分析记录的自主神经功能测试、心率和 BP 对直立、深呼吸和等长握力的反应，以及生化参数（稳态模型评估的胰岛素抵抗、血脂危险因素、炎症标志物、甲状腺功能、肾素和氧化应激参数），并在年轻的正常血压者（n=118）和高血压前期患者（n=58）中进行了分析。通过多元回归分析确定了 CV 风险对 HRV 的低频/高频（LF/HF）比值（SVI 的标志物）的贡献，通过对体重指数进行调整的逻辑回归评估了 SVI 对 RPP（已知的 CV 风险）的预测作用。高血压前期患者的 BP 变异性、HRV 和自主神经功能测试参数均发生显著改变，且这些参数与 LF/HF 呈正相关。胰岛素抵抗、血脂异常、炎症和氧化应激均导致高血压前期患者 SVI 的发生。LF/HF 和压力反射敏感性对高血压前期患者的 RPP 具有显著的预测作用。总之，年轻高血压前期患者的 SVI 是由于交感神经活动增加和迷走神经活动减少所致。CV 风险与 SVI 相关，SVI 可预测高血压前期患者的心脏风险。
