School of Health Sciences, Massey University, Wellington, New Zealand.
School of Sport, Exercise and Nutrition, Massey University, Palmerston North, New Zealand.
Physiol Rep. 2022 May;10(9):e15287. doi: 10.14814/phy2.15287.
There is emerging evidence that ovarian hormones play a significant role in the lower stroke incidence observed in pre-menopausal women compared with men. However, the role of ovarian hormones in cerebrovascular regulation remains to be elucidated. We examined the blood pressure-cerebral blood flow relationship (cerebral autoregulation) across the menstrual cycle in eumenorrheic women (n = 12; mean ± SD: age, 31 ± 7 years). Participants completed sit-to-stand and Valsalva maneuvers (VM, mouth pressure of 40 mmHg for 15 s) during the early follicular (EF), late follicular (LF), and mid-luteal (ML) menstrual cycle phases, confirmed by serum measurement of progesterone and 17β-estradiol. Middle cerebral artery blood velocity (MCAv), arterial blood pressure and partial pressure of end-tidal carbon dioxide were measured. Cerebral autoregulation was assessed by transfer function analysis during spontaneous blood pressure oscillations, rate of regulation (RoR) during sit-to-stand maneuvers, and Tieck's autoregulatory index during VM phases II and IV (AI-II and AI-IV, respectively). Resting mean MCAv (MCAv ), blood pressure, and cerebral autoregulation were unchanged across the menstrual cycle (all p > 0.12). RoR tended to be different (EF, 0.25 ± 0.06; LF; 0.19 ± 0.04; ML, 0.18 ± 0.12 sec ; p = 0.07) and demonstrated a negative relationship with 17β-estradiol (R = 0.26, p = 0.02). No changes in AI-II (EF, 1.95 ± 1.20; LF, 1.67 ± 0.77 and ML, 1.20 ± 0.55) or AI-IV (EF, 1.35 ± 0.21; LF, 1.27 ± 0.26 and ML, 1.20 ± 0.2) were observed (p = 0.25 and 0.37, respectively). Although, a significant interaction effect (p = 0.02) was observed for the VM MCAv response. These data indicate that the menstrual cycle has limited impact on cerebrovascular autoregulation, but individual differences should be considered.
有证据表明，与男性相比，卵巢激素在绝经前女性较低的中风发病率中起着重要作用。然而，卵巢激素在脑血管调节中的作用仍有待阐明。我们在月经周期正常的女性（n=12；平均±标准差：年龄 31±7 岁）中检查了血压-脑血流关系（脑自动调节）。参与者在卵泡早期（EF）、卵泡晚期（LF）和黄体中期（ML）月经周期阶段完成了从坐到站和瓦尔萨尔瓦动作（VM，口腔压力为 40mmHg 持续 15s），通过血清孕激素和 17β-雌二醇的测量来确认。测量大脑中动脉血流速度（MCAv）、动脉血压和呼气末二氧化碳分压。在自发性血压波动期间通过传递函数分析评估脑自动调节，在从坐到站的动作期间评估调节率（RoR），在 VM 阶段 II 和 IV 期间评估 Tieck 自动调节指数（AI-II 和 AI-IV，分别）。整个月经周期内，平均 MCAv（MCAv）、血压和脑自动调节均无变化（均 p>0.12）。RoR 趋于不同（EF，0.25±0.06；LF，0.19±0.04；ML，0.18±0.12sec；p=0.07），与 17β-雌二醇呈负相关（R=0.26，p=0.02）。AI-II 无变化（EF，1.95±1.20；LF，1.67±0.77 和 ML，1.20±0.55）或 AI-IV（EF，1.35±0.21；LF，1.27±0.26 和 ML，1.20±0.2）（p=0.25 和 0.37，分别）。尽管在 VM MCAv 反应中观察到显著的交互效应（p=0.02）。这些数据表明，月经周期对脑血管自动调节的影响有限，但应考虑个体差异。
