NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, DF, Brazil.
NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasília, Brasília, DF, Brazil; Graduate Program in Medical Sciences, Faculty of Medicine, University of Brasília, Brasília, DF, Brazil.
Auton Neurosci. 2020 Nov;228:102714. doi: 10.1016/j.autneu.2020.102714. Epub 2020 Aug 13.
A parasympathetic reactivation is an underlying mechanism mediating the rapid fall in heart rate (HR) at the onset of post-exercise ischemia (PEI) in humans. Herein, we tested the hypothesis that, compared to men, women present a slower HR recovery at the cessation of isometric handgrip exercise (i.e., onset of PEI) due to an attenuated cardiac vagal reactivation. Forty-seven (23 women) young and healthy volunteers were recruited. Subjects performed 90s of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 3-min of PEI. The onset of PEI was analyzed over the first 30s in 10s windows. Cardiac vagal reactivation was indexed using the HR fall and by HR variability metrics (e.g., RMSSD and SDNN) immediately after the cessation of the exercise. HR was significantly increased from rest during exercise in men and women and increases were similar between sexes. However, following the cessation of exercise, the HR recovery was significantly slower in women compared to men regardless of the time point (women vs. men: ∆-14 ± 8 vs. ∆-18 ± 6 beats.min at 10s; ∆-20 ± 9 vs. ∆-25 ± 8 beats.min at 20s; ∆-22 ± 10 vs. ∆-27 ± 9 beats.min at 30s; P = .027). RMSSD and SDNN increased at the cessation of exercise in greater magnitude in men compared to women. These findings demonstrate that women had a slower HR recovery at the cessation of isometric handgrip exercise and onset of PEI compared to men, suggesting a sex-related difference in cardiac vagal reactivation in healthy young humans.
副交感神经再激活是介导人体运动后缺血（PEI）发作时心率（HR）快速下降的潜在机制。在此，我们假设与男性相比，女性在等长握力运动停止时（即 PEI 发作时）表现出较慢的 HR 恢复，这是由于心脏迷走神经再激活减弱。招募了 47 名（23 名女性）年轻健康的志愿者。受试者进行 90 秒 40%最大自主收缩的等长握力运动，然后进行 3 分钟的 PEI。在 10 秒的窗口中分析 PEI 发作的前 30 秒。HR 下降和 HR 变异性指标（例如，RMSSD 和 SDNN）可用于评估运动停止后即刻的心脏迷走神经再激活。在男女中，HR 在运动期间均显著高于休息时，且性别之间的增加相似。然而，运动停止后，女性的 HR 恢复明显比男性慢，无论时间点如何（女性与男性：10 秒时的 -14±8 与 -18±6 次/分；20 秒时的 -20±9 与 -25±8 次/分；30 秒时的 -22±10 与 -27±9 次/分；P=0.027）。在运动停止时，RMSSD 和 SDNN 的增加幅度大于女性。这些发现表明，与男性相比，女性在等长握力运动停止和 PEI 发作时 HR 恢复较慢，提示健康年轻人群中存在与性别相关的心脏迷走神经再激活差异。
