Baksi Arun J, Treibel Thomas A, Davies Justin E, Hadjiloizou Nearchos, Foale Rodney A, Parker Kim H, Francis Darrel P, Mayet Jamil, Hughes Alun D
International Centre for Circulatory Health, St Mary's Hospital, Imperial College Healthcare NHS Trust and Imperial College London, London, United Kingdom.
J Am Coll Cardiol. 2009 Nov 24;54(22):2087-92. doi: 10.1016/j.jacc.2009.06.049.
We undertook a meta-analysis to determine whether changes in wave reflection substantiate the consensus explanation of why blood pressure (BP) changes with aging.
Consensus documents attribute the aging changes in BP to wave reflection moving progressively from diastole into systole. However, the extensive quantitative data on this phenomenon have never been systematically reviewed. Individual studies have been small, and limited to a narrow age range.
Using PubMed, Cochrane, and Web of Science databases, we identified 64 studies (including 13,770 subjects, age range 4 to 91 years) reporting the timing of wave reflection, defined as the time from the onset (foot) of the pressure waveform to the shoulder point (anachrotic notch).
In subjects of all ages, reflection times were well within systole. There was a small tendency for younger subjects to have later reflection, but this was only 0.7 ms per year, whereas the weighted mean reflection time was 136 ms (99% confidence interval: 130 to 141 ms) and the mean duration of systole was 328 ms (99% confidence interval: 310 to 347 ms). At this rate of change with age, arrival of wave reflection would only be construed to be in diastole at an extrapolated age of -221 years.
These findings challenge the current consensus view that a shift in timing of wave reflection significantly contributes to the changes in the BP waveform with aging. We should re-evaluate the mechanisms of BP elevation in aging.
我们进行了一项荟萃分析，以确定波反射的变化是否能证实关于血压（BP）随年龄增长而变化的共识解释。
共识文件将血压的年龄增长变化归因于波反射逐渐从舒张期转移到收缩期。然而，关于这一现象的大量定量数据从未得到系统回顾。个别研究规模较小，且仅限于狭窄的年龄范围。
利用PubMed、Cochrane和科学网数据库，我们识别出64项研究（包括13770名受试者，年龄范围为4至91岁），这些研究报告了波反射的时间，波反射定义为从压力波形的起始点（足部）到肩点（切迹）的时间。
在所有年龄段的受试者中，反射时间均处于收缩期内。年轻受试者的反射时间有稍晚的趋势，但每年仅晚0.7毫秒，而加权平均反射时间为136毫秒（99%置信区间：130至141毫秒），收缩期的平均持续时间为328毫秒（99%置信区间：310至347毫秒）。按照这种随年龄的变化率，只有在外推年龄达到-221岁时，波反射的到达时间才会被认为处于舒张期。
这些发现挑战了当前的共识观点，即波反射时间的改变对血压波形随年龄增长的变化有显著贡献。我们应该重新评估衰老过程中血压升高的机制。
