Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Menopause. 2010 May-Jun;17(3):456-61. doi: 10.1097/gme.0b013e3181c7dea7.
The understanding of the physiology of hot flashes is incomplete. The autonomic nervous system has been hypothesized to play a role in hot flashes but has received limited empirical attention. Furthermore, emerging research has linked hot flashes to cardiovascular risk. Reduced high-frequency heart rate variability (HF-HRV), an index of vagal control of heart rate, has been associated with cardiovascular events. We hypothesized that decreases in HF-HRV would occur during hot flashes relative to periods before and after hot flashes.
Thirty perimenopausal and postmenopausal women aged 40 to 60 years reporting four or more hot flashes per day underwent laboratory hot flash provocation testing, with electrocardiogram and measurement of sternal skin conductance. Hot flashes were reported and identified from sternal skin conductance. HF-HRV was estimated using spectral analysis of the heart rate time series. The 5-minute interval during the hot flash period was compared with that during two nonflash periods before and after the hot flash via mixed-effects models.
HRV was significantly decreased during hot flashes relative to periods before (b = 0.18, SE = 0.05; P = 0.0001) and after (b = 0.16, SE = 0.05; P = 0.002) physiologically measured hot flashes, controlling for age, race, education, task condition, menopause status, task, hypertension status, diabetes status, physical activity, body mass index, smoking, and anxiety. Findings were unchanged when considering self-reported hot flashes.
Significant decreases in cardiac vagal control occurred during hot flashes, which may help shed light on the physiology of hot flashes. The autonomic nervous system may deserve greater attention in understanding the mechanisms linking hot flashes to cardiovascular risk.
对热潮发生的生理学机制仍缺乏了解。自主神经系统被认为在热潮发生中起作用，但得到的实证关注有限。此外，新出现的研究将热潮与心血管风险联系起来。高频心率变异性（HF-HRV）降低，即心率迷走神经控制的指标，与心血管事件相关。我们假设 HF-HRV 在热潮期间会相对于热潮前后的时期下降。
30 名年龄在 40 岁至 60 岁之间、报告每天有 4 次或更多热潮的绝经前期和绝经后妇女接受了实验室热潮诱发测试，同时进行心电图和胸骨皮肤电导率测量。从胸骨皮肤电导率报告和识别热潮。使用心率时间序列的频谱分析来估计 HF-HRV。通过混合效应模型，将热潮期间的 5 分钟间隔与热潮前后的两个非热潮期间进行比较。
与生理测量的热潮前（b=0.18，SE=0.05；P=0.0001）和热潮后（b=0.16，SE=0.05；P=0.002）相比，HRV 在热潮期间显著降低，控制年龄、种族、教育、任务条件、绝经状态、任务、高血压状态、糖尿病状态、身体活动、体重指数、吸烟和焦虑。当考虑自我报告的热潮时，结果仍然不变。
在热潮期间，心脏迷走神经控制显著降低，这可能有助于阐明热潮的生理学机制。自主神经系统在理解热潮与心血管风险之间的联系的机制方面可能值得更多关注。
