Atkinson Greg, Leary Andrew C, George Keith P, Murphy Michael B, Jones Helen
Research Institute for Sport and Exercise Sciences, Liverpool John Moores, Liverpool, UK.
Chronobiol Int. 2009 Jul;26(5):958-73. doi: 10.1080/07420520903044455.
The exercise-related response of the rate-pressure-product (RPP) is a prognostic marker of autonomic imbalance, cardiovascular mortality, and silent myocardial ischemia in hypertension. In view of the well-known 24 h variation in out-of-hospital sudden cardiac events, our aim was to investigate whether the reactivity of RPP to everyday physical activities varies over the 24 h. Ambulatory measurements of systolic blood pressure (BP) and heart rate were recorded every 20 min for 24 h in 440 diurnally active patients attending a hypertension clinic. Wrist activity counts were summed over the 15 min that preceded a BP measurement. An RPP reactivity index was derived for each of twelve 2 h data bins by regressing the change in RPP against the change in logged activity counts. The RPP showed 24 h variation (p < 0.0005), with a peak of 11,004 (95% CI = 10,757 to 11,250) beat . min(-1) . mmHg occurring at 10:00 h (2 h after mean wake-time). The overall 24 h mean of RPP reactivity was 477 beat . min(-1) . mmHg . logged activity counts(-1) (95% CI = 426 to 529). The largest increase in RPP reactivity occurred within the first 2 h after waking (p < 0.0005). There were no subsequent significant differences in RPP reactivity up to 14 h after waking. The lowest RPP reactivity was found 18-20 h after waking, with a peak-to-trough variation of 593 beat . min(-1) . mmHg . logged activity counts(-1) (95% CI = 394 to 791, p < 0.0005). Although this variation was not moderated by BP status, age, or sex, less variability in RPP reactivity was found for the medicated individuals during the waking hours. These data suggest that under conditions of normal living, the reactivity of RPP to a given change in physical activity increases markedly during the first 2 h after waking from nocturnal sleep, the time when out-of-hospital sudden cardiac events are also most common. Therefore, these data add weight to the notion that reactivity of RPP to physical activity could be a prognostic marker of autonomic imbalance and cardiovascular mortality, although more research is needed to assess the specific prognostic value of 24 h ambulatory measurements of RPP and physical activity.
心率血压乘积（RPP）与运动相关的反应是高血压患者自主神经失衡、心血管死亡率和无症状心肌缺血的一项预后指标。鉴于院外心脏猝死事件存在众所周知的24小时变化规律，我们的目的是研究RPP对日常体力活动的反应性在24小时内是否有所不同。对440名日间活动的高血压门诊患者进行了24小时动态监测，每20分钟记录一次收缩压（BP）和心率。在每次血压测量前的15分钟内汇总手腕活动计数。通过将RPP的变化与记录的活动计数的变化进行回归分析，得出了12个2小时数据区间中每个区间的RPP反应性指数。RPP显示出24小时变化（p<0.0005），在10:00（平均醒来时间后2小时）达到峰值11,004（95%CI=10,757至11,250）次·分钟⁻¹·毫米汞柱。RPP反应性的24小时总体平均值为477次·分钟⁻¹·毫米汞柱·记录活动计数⁻¹（95%CI=426至529）。RPP反应性最大的增加发生在醒来后的前2小时内（p<0.0005）。醒来后长达14小时内，RPP反应性没有后续显著差异。醒来后18 - 20小时发现RPP反应性最低，峰谷变化为593次·分钟⁻¹·毫米汞柱·记录活动计数⁻¹（95%CI=394至791，p<0.0005）。尽管这种变化不受血压状态、年龄或性别的影响，但在清醒时间内，用药个体的RPP反应性变异性较小。这些数据表明，在正常生活条件下，从夜间睡眠醒来后的前2小时内，RPP对给定体力活动变化的反应性显著增加，而这也是院外心脏猝死事件最常见的时间。因此，这些数据进一步支持了RPP对体力活动的反应性可能是自主神经失衡和心血管死亡率的预后指标这一观点，尽管还需要更多研究来评估24小时动态测量RPP和体力活动的具体预后价值。
