Delgado-Aranda Raquel, Dorantes-Méndez Guadalupe, Bianchi Anna Maria, Kortelainen Juha M, Coelli Stefania, Jimenez-Cruz Jorge, Méndez Martin O
Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milano, Italy.
Front Neuroergon. 2024 May 9;5:1382919. doi: 10.3389/fnrgo.2024.1382919. eCollection 2024.
Sleep-wake cycle disruption caused by shift work may lead to cardiovascular stress, which is observed as an alteration in the behavior of heart rate variability (HRV). In particular, HRV exhibits complex patterns over different time scales that help to understand the regulatory mechanisms of the autonomic nervous system, and changes in the fractality of HRV may be associated with pathological conditions, including cardiovascular disease, diabetes, or even psychological stress. The main purpose of this study is to evaluate the multifractal-multiscale structure of HRV during sleep in healthy shift and non-shift workers to identify conditions of cardiovascular stress that may be associated with shift work.
The whole-sleep HRV signal was analyzed from female participants: eleven healthy shift workers and seven non-shift workers. The HRV signal was decomposed into intrinsic mode functions (IMFs) using the empirical mode decomposition method, and then the IMFs were analyzed using the multiscale-multifractal detrended fluctuation analysis (MMF-DFA) method. The MMF-DFA was applied to estimate the self-similarity coefficients, α(, τ), considering moment orders () between -5 and +5 and scales (τ) between 8 and 2,048 s. Additionally, to describe the multifractality at each τ in a simple way, a multifractal index, (τ), was computed.
Compared to non-shift workers, shift workers presented an increase in the scaling exponent, α(, τ), at short scales (τ < 64 s) with < 0 in the high-frequency component (IMF1, 0.15-0.4 Hz) and low-frequency components (IMF2-IMF3, 0.04-0.15 Hz), and with > 0 in the very low frequencies (IMF4, < 0.04 Hz). In addition, at large scales (τ> 1,024 s), a decrease in α(, τ) was observed in IMF3, suggesting an alteration in the multifractal dynamic. (τ) showed an increase at small scales and a decrease at large scales in IMFs of shift workers.
This study helps to recognize the multifractality of HRV during sleep, beyond simply looking at indices based on means and variances. This analysis helps to identify that shift workers show alterations in fractal properties, mainly on short scales. These findings suggest a disturbance in the autonomic nervous system induced by the cardiovascular stress of shift work.
轮班工作导致的睡眠-觉醒周期紊乱可能会引发心血管应激，这在心率变异性（HRV）行为改变中有所体现。特别是，HRV在不同时间尺度上呈现出复杂模式，有助于理解自主神经系统的调节机制，HRV分形性的变化可能与包括心血管疾病、糖尿病甚至心理应激在内的病理状况相关。本研究的主要目的是评估健康轮班和非轮班工作者睡眠期间HRV的多重分形-多尺度结构，以确定可能与轮班工作相关的心血管应激状况。
对女性参与者的全睡眠HRV信号进行分析：11名健康轮班工作者和7名非轮班工作者。使用经验模式分解方法将HRV信号分解为固有模态函数（IMF），然后使用多尺度-多重分形去趋势波动分析（MMF-DFA）方法对IMF进行分析。应用MMF-DFA估计自相似系数α(, τ)，考虑-5到+5之间的矩阶（）和8到2048秒之间的尺度（τ）。此外，为了以简单的方式描述每个τ处的多重分形性，计算了一个多重分形指数(τ)。
与非轮班工作者相比，轮班工作者在短尺度（τ < 64秒）下，高频成分（IMF1，0.15 - 0.4赫兹）和低频成分（IMF2 - IMF3，0.04 - 0.15赫兹）中< 0时，尺度指数α(, τ)增加，在极低频（IMF4，< 0.04赫兹）中> 0时，尺度指数α(, τ)增加。此外，在大尺度（τ > 1024秒）下，IMF3中观察到α(, τ)下降，表明多重分形动态发生改变。轮班工作者的IMF中，(τ)在小尺度下增加，在大尺度下减少。
本研究有助于认识睡眠期间HRV的多重分形性，而不仅仅是简单地查看基于均值和方差的指标。该分析有助于确定轮班工作者的分形特性发生改变，主要是在短尺度上。这些发现表明轮班工作的心血管应激会引起自主神经系统的紊乱。
