■雌激素和孕激素水平在整个月经周期中都会发生变化。关于中枢血容量不足期间月经期对心血管和自主神经调节的影响的现有文献是矛盾的。
■本研究旨在探讨月经期对静息和下体负压(LBNP)引起的中枢低血容量时的心血管和自主神经反应的影响。这是一篇同伴论文,其中来自健康年轻女性的月经期数据,其结果在Shankwar等人中报道。(2023),进一步分析。
■研究方案包括三个阶段:(1)仰卧休息30分钟;(2)四个LBNP水平16分钟;(3)仰卧恢复5分钟。血流动力学和自主神经反应(通过心率变异性评估,HRV)在之前测量-,during-,以及使用TaskForceMonitor®(CNSystems,格拉茨,奥地利)。还收集血液以测量雌激素和孕酮水平。
■在本文中,我们仅评估了先前研究中的14名女性(Shankwar等人.,2023年):月经周期的卵泡期8岁(平均年龄23.38±3.58岁,高度166.00±5.78厘米,体重57.63±5.39kg,BMI为20.92±1.9625kg/m2)和黄体期6(平均年龄22.17±1.33岁,身高169.83±5.53厘米,体重62.00±7.54kg,BMI为21.45±2.63kg/m2)。与黄体期相比,基线雌激素水平与卵泡期明显不同:(33.59pg/ml,108.02pg/ml,分别,p<0.01)。静息血液动力学变量在整个月经期没有差异。然而,处于卵泡期的女性显示出低频(LF)波段功率的静息值显着降低(41.38±11.75n.u.和58.47±14.37n.u.,p=0.01),但高频(HF)频带功率的静息值较高(58.62±11.75n.u.和41.53±14.37n.u.,p=0.01),与黄体期的女性相比。在血容量不足期间,LF和HF频带功率分别仅在卵泡期F(1,7)=77.34,p<0.0001和F(1,7)=520.06,p<0.0001中变化。
■月经期对静息自主神经变量有影响,在黄体期观察到更高的交感神经活动。中枢低血容量导致心血管和自主神经反应增加,特别是在月经周期的黄体期,可能是由于雌激素水平升高和交感神经活动增加。
Estrogen and progesterone levels undergo changes throughout the menstrual cycle. Existing literature regarding the effect of menstrual phases on cardiovascular and autonomic regulation during central hypovolemia is contradictory.
This study aims to explore the influence of menstrual phases on cardiovascular and autonomic responses in both resting and during the central hypovolemia induced by lower body negative pressure (LBNP). This is a companion paper, in which data across the menstrual phases from healthy young females, whose results are reported in Shankwar et al. (2023), were further analysed.
The study protocol consisted of three phases: (1) 30 min of supine rest; (2) 16 min of four LBNP levels; and (3) 5 min of supine recovery. Hemodynamic and autonomic responses (assessed via heart rate variability, HRV) were measured before-, during-, and after-LBNP application using Task Force Monitor® (CNSystems, Graz, Austria). Blood was also collected to measure estrogen and progesterone levels.
In this companion paper, we have exclusively assessed 14 females from the previous study (Shankwar et al., 2023): 8 in the follicular phase of the menstrual cycle (mean age 23.38 ± 3.58 years, height 166.00 ± 5.78 cm, weight 57.63 ± 5.39 kg and BMI of 20.92 ± 1.96 25 kg/m2) and 6 in the luteal phase (mean age 22.17 ± 1.33 years, height 169.83 ± 5.53 cm, weight 62.00 ± 7.54 kg and BMI of 21.45 ± 2.63 kg/m2). Baseline estrogen levels were significantly different from the follicular phase as compared to the luteal phase: (33.59 pg/ml, 108.02 pg/ml, respectively, p < 0.01). Resting hemodynamic variables showed no difference across the menstrual phases. However, females in the follicular phase showed significantly lower resting values of low-frequency (LF) band power (41.38 ± 11.75 n.u. and 58.47 ± 14.37 n.u., p = 0.01), but higher resting values of high frequency (HF) band power (58.62 ± 11.75 n.u. and 41.53 ± 14.37 n.u., p = 0.01), as compared to females in the luteal phase. During hypovolemia, the LF and HF band powers changed only in the follicular phase F(1, 7) = 77.34, p < 0.0001 and F(1, 7) = 520.06, p < 0.0001, respectively.
The menstrual phase had an influence on resting autonomic variables, with higher sympathetic activity being observed during the luteal phase. Central hypovolemia leads to increased cardiovascular and autonomic responses, particularly during the luteal phase of the menstrual cycle, likely due to higher estrogen levels and increased sympathetic activity.