Perseguini Natália Maria, de Medeiros Takahashi Anielle Cristhine, Milan Juliana Cristina, dos Santos Patrícia Rehder, Neves Valéria Ferreira Camargo, Borghi-Silva Audrey, Silva Ester, Montano Nicola, Porta Alberto, Catai Aparecida Maria
Cardiovascular Physical Therapy Laboratory, Nucleus of Research in Physical Exercise (NUPEF), Department of Physical Therapy, Federal University of São Carlos, UFSCar, Via Washington Luiz, km 235, São Carlos, SP, 13565-905, Brazil.
Clin Auton Res. 2014 Apr;24(2):63-70. doi: 10.1007/s10286-014-0226-1. Epub 2014 Feb 12.
To investigate the effects of hormone replacement therapy (HRT) on heart rate variability (HRV) in healthy postmenopausal women.
Two groups were evaluated: group 1 (G1): 20 women not undergoing HRT (60 ± 5.89 years), group 2 (G2): 20 women undergoing HRT (59 ± 5.70 years). The HRTs involved were either conjugated equine estrogen with or without medroxyprogesterone, synthetic estrogen hormone, estradiol associated with norethisterone acetate or isoflavonoids. Electrocardiogram was recorded in the supine position for 10 min. Spectral analysis included low and high frequencies in absolute (LF and HF) and normalized units (LFnu and HFnu), which are predominantly cardiac sympathetic modulation (CSM) and cardiac vagal modulation (CVM) indicators, respectively. The LF/HF ratio was also calculated. Symbolic analysis involved the following indexes: 0V % (CSM indicator), 1V % (CSM and CVM indicators), 2LV % (predominantly CVM indicator) and 2UV % (CVM indicator). Shannon and conditional entropies were also calculated.
Spectral analysis demonstrated that HRT affected HRV. LF, LFnu and LF/HF ratio were higher (showing increased CSM), while HFnu was lower (representing decreased CVM) in G2 than in G1. Correlations between complexity indices and HFnu were significant and positive only in G1.
Women undergoing HRT presented higher CSM and lower CVM than those who were not. Moreover, the expected positive relationship between CVM and complexity of HRV was found only in control group, thus indicating that CVM in women under therapy drop below a minimal value necessary to the association to become apparent, suggesting an unfavorable cardiac autonomic modulation in spite of HRT.
探讨激素替代疗法（HRT）对健康绝经后女性心率变异性（HRV）的影响。
评估两组：第1组（G1）：20名未接受HRT的女性（60±5.89岁），第2组（G2）：20名接受HRT的女性（59±5.70岁）。所涉及的HRT包括结合马雌激素加或不加甲羟孕酮、合成雌激素激素、与醋酸炔诺酮相关的雌二醇或异黄酮。在仰卧位记录心电图10分钟。频谱分析包括绝对（低频和高频）和标准化单位（低频标准化值和高频标准化值）中的低频和高频，它们分别主要是心脏交感神经调制（CSM）和心脏迷走神经调制（CVM）指标。还计算了低频/高频比值。符号分析涉及以下指标：0V%（CSM指标）、1V%（CSM和CVM指标）、2LV%（主要是CVM指标）和2UV%（CVM指标）。还计算了香农熵和条件熵。
频谱分析表明HRT影响HRV。G2组的低频、低频标准化值和低频/高频比值较高（表明CSM增加），而高频标准化值较低（代表CVM降低），高于G1组。复杂性指标与高频标准化值之间的相关性仅在G1组中显著且呈正相关。
接受HRT的女性比未接受HRT的女性表现出更高的CSM和更低的CVM。此外，仅在对照组中发现CVM与HRV复杂性之间预期的正相关关系，因此表明接受治疗的女性的CVM降至关联变得明显所需的最小值以下，提示尽管进行了HRT，但心脏自主神经调制不利。
