Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan. Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya 467-8602, Japan. J Hayano and K Ohashi contributed equally to this study.
Physiol Meas. 2018 May 25;39(5):054004. doi: 10.1088/1361-6579/aac007.
To adapt to a new environment or situation, biological systems explore the most convenient state while moving between attractors by the force of random fluctuation. From this concept, the random component in physiological signals is assumed to increase during developmental and degenerative stages of life. To examine this hypothesis, we measured the age-dependent changes in the random component of heart rate variability (HRV) in 24-h electrocardiography (ECG) big data and in patients with a developmental disorder (DD).
We measured separately regulated and random components of HRV with autoregressive (AR) model fitting, by which the ratio of random component as the fractional variance of AR residual time series. From the ALLSTAR database of about 304 000 ambulatory 24-h ECGs, we randomly extracted the data of 1930 men and 1987 women uniformly for all ages from 0 to 100 years old (100 cases per 5-year strata for each sex). Data were also obtained from male pediatric patients with DD (age 10-15 years).
While the variance of the regulated component of HRV increased from age 0 to 20, decreased with age until 40, and reached a plateau in both sexes, the ratio of the random component was high at birth, decreased with age until 35 in men and 30 in women, and increased again after 75 in men and 85 in women (P < 0.0001 for all). In patients with a DD, the ratio of the random component was significantly lower than that in age-and-sex matched subjects in the database.
We found that the ratio of the random component of HRV is increased during developmental and degenerative stages of life and that it may be reduced in DD patients during their development.
为了适应新的环境或情况，生物系统在通过随机波动的力在吸引子之间移动时，会探索最便捷的状态。基于这一概念，人们假设生理信号中的随机成分在生命的发育和退行阶段会增加。为了检验这一假设，我们测量了 24 小时心电图（ECG）大数据中以及发育障碍（DD）患者的心率变异性（HRV）的随机分量随年龄的变化。
我们分别通过自回归（AR）模型拟合来测量 HRV 的规则分量和随机分量，其中随机分量为 AR 残差时间序列的分数方差的比值。从大约 304000 份动态 24 小时 ECG 的 ALLSTAR 数据库中，我们随机提取了 1930 名男性和 1987 名女性的数据，年龄从 0 岁到 100 岁（每 5 岁为一个年龄层，每个性别各有 100 例）。还从患有 DD 的男性儿科患者（年龄 10-15 岁）中获得了数据。
虽然 HRV 的规则分量的方差从 0 岁到 20 岁增加，然后随着年龄的增长直到 40 岁下降，并且在两性中都达到了一个平台，但随机分量的比值在出生时较高，在男性中直到 35 岁和女性中直到 30 岁时下降，然后在男性中 75 岁以上和女性中 85 岁以上再次增加（所有 P 值均<0.0001）。在 DD 患者中，随机分量的比值明显低于数据库中年龄和性别匹配的受试者。
我们发现，HRV 的随机分量的比值在生命的发育和退行阶段增加，并且在 DD 患者的发育过程中可能降低。
