International Collaboration on Repair Discoveries, Faculty of Medicine, University of British Columbia, Vancouver, BC, V5Z 1M9, Canada.
Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, V5Z 2G9, Canada.
Sci Rep. 2023 Aug 14;13(1):13185. doi: 10.1038/s41598-023-40385-1.
Aging is commonly regarded as a physiological process in which the dynamic complexity of physiological time series and organ systems is gradually lost. This notion is derived from the identification of a decline of nonlinear measures with the advance of aging. However, additional research on cardiovascular control studied through heart rate variability (HRV), i.e., the instantaneous changes in heart rate, shows that despite the constriction of its statistical distribution, the nonlinear organization remains present in advanced age. Here, we used surrogate data testing to investigate the presence of nonlinear information in HRV time series from a publicly available database of 1121 healthy human subjects from 18 to 92 years old. We also studied the influence of basic clinical features, such as sex, body mass index (BMI), and mean heart rate (HR), on such nonlinear information. We found that the percentage of nonlinear time series after 30 years of age diminishes significantly (p < 0.01). Furthermore, larger BMI and HR are associated with the presence of more linear information in HRV, while the female sex is associated with the manifestation of nonlinear information. This work provides a common background for the contextualized interpretation of nonlinear testing and shows that the nonlinear content of HRV time series diminishes through aging.
衰老是一个普遍的生理过程，在此过程中，生理时间序列和器官系统的动态复杂性逐渐丧失。这种观点源于随着年龄的增长，非线性指标的下降的识别。然而，通过心率变异性（HRV）研究心血管控制的进一步研究，即心率的瞬时变化，表明尽管其统计分布收缩，但非线性组织在老年时仍然存在。在这里，我们使用替代数据测试来研究来自 1121 名健康人类受试者的公开可用数据库的 HRV 时间序列中是否存在非线性信息，这些受试者年龄在 18 至 92 岁之间。我们还研究了基本临床特征，如性别、体重指数（BMI）和平均心率（HR）对这种非线性信息的影响。我们发现，30 岁以后非线性时间序列的百分比明显减少（p < 0.01）。此外，较大的 BMI 和 HR 与 HRV 中存在更多线性信息相关，而女性则与非线性信息的表现相关。这项工作为非线性测试的上下文解释提供了一个共同的背景，并表明 HRV 时间序列的非线性内容随着年龄的增长而减少。
