Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada.
Appl Physiol Nutr Metab. 2012 Apr;37(2):301-7. doi: 10.1139/h11-163. Epub 2012 Mar 22.
Low baroreflex sensitivity (BRS) and heart rate variability (HRV) are associated with the pathogenesis of adult hypertension. However, limited information exists about the negative consequences of elevated childhood blood pressure (BP) and autonomic regulation. Additionally, there are developmental changes in autonomic regulation throughout puberty, yet studies have not appropriately accounted for this. The objective of this study was to investigate BRS and HRV in children with 2 different BP profiles, while controlling for the effects of maturation, age, sex, and body composition. A sample of 11- to 14-year-old participants were divided into 2 BP groups: high BP (HBP; ≥95th percentile; n = 21) and normal BP (NBP; <90th percentile; n = 85). Automated BP was measured at 2 time points. In lab-based testing, 5 min of beat-to-beat BP (Finapres) and R-R interval (RRI) were recorded (standard electrocardiogram) after 15 min of supine rest. Spectral indices were computed using fast Fourier transform, and transfer function analysis was used to compute BRS. High frequency (HF) and low frequency (LF) power spectral areas were set to 0.15-0.4 Hz and 0.04-0.15 Hz, respectively, and BRS was determined for the LF area. After adjustment for age, sex, maturation, and body composition, BRS (p = 0.04), LF (p = 0.008), and HF (p = 0.01) RRI variability, and RRI total power (p = 0.005) were lower in the HBP than in the NBP participants. As well, the LF/HF systolic BP variability ratio was higher in the HBP than in the NBP group (p = 0.03). Despite their young age, these children with high, yet not clinically hypertensive BP, display reduced autonomic regulation.
血压反射敏感性（BRS）和心率变异性（HRV）与成人高血压的发病机制有关。然而，关于儿童血压升高和自主调节的负面影响的信息有限。此外，自主调节在整个青春期都有发育变化，但研究并未对此进行适当考虑。本研究的目的是在控制成熟度、年龄、性别和身体成分影响的情况下，研究具有两种不同血压谱的儿童的 BRS 和 HRV。研究对象为 11 至 14 岁的参与者，他们被分为两组：高血压组（HBP；≥95 百分位数；n = 21）和正常血压组（NBP；<90 百分位数；n = 85）。采用自动血压测量仪在两个时间点测量血压。在实验室测试中，在仰卧休息 15 分钟后，使用 Finapres 记录 5 分钟的逐搏血压（BP）和 R-R 间期（RRI）（标准心电图）。使用快速傅里叶变换计算频谱指数，并使用传递函数分析计算 BRS。高频（HF）和低频（LF）功率谱面积分别设置为 0.15-0.4 Hz 和 0.04-0.15 Hz，BRS 为 LF 面积。在调整年龄、性别、成熟度和身体成分后，HBP 组的 BRS（p = 0.04）、LF（p = 0.008）和 HF（p = 0.01）RRI 变异性以及 RRI 总功率（p = 0.005）均低于 NBP 组。此外，HBP 组的 LF/HF 收缩压变异性比值高于 NBP 组（p = 0.03）。尽管这些儿童年龄较小，但他们的血压偏高，尽管尚未达到高血压水平，但自主调节能力却有所下降。
