title: Autonomic control of cardiovascular system in pre- and postmenopausal women: a cross-sectional study.
abstract: OBJECTIVE
  The aim of this cross-sectional study was to assess the features of autonomic control of the cardiovascular system in pre- and postmenopausal women.
  
  
  METHODS
  We studied 185 postmenopausal women aged 59.3±8.5 years (mean±SD) and 104 premenopausal women aged 45.1±5.8 years. Standard indices of heart rate variability (HRV) (mean heart rate, coefficient of variation, standard deviation of the NN interval (the time elapsing between two consecutive R waves in the electrocardiogram with normal sinus rhythm) (SDNN), square root of the mean squared differences of successive NN intervals (RMSSD), proportion derived by dividing RR50, the number of interval differences of successive NN intervals greater than 50 ms, by the total number of NN intervals (PNN50), and power of low frequency (LF) and high frequency (HF) bands in absolute values and percentages of total spectral power) and index S of synchronization between the 0.1-Hz rhythms in heart rate and photoplethysmogram were compared between these two groups at rest. We assessed the following sex hormones: estradiol, follicle stimulating hormone, dehydroepiandrosterone sulfate, and testosterone.
  
  
  RESULTS
  Mean heart rate and power of LF and HF bands were significantly different (p<0.05) in pre- and postmenopausal women. The autonomic indices were similar in women with natural and surgical menopause. Some indices (coefficient of variation, SDNN, RMSSD, PNN50, and power of LF and HF bands) showed weak correlation with menopause time in women with natural menopause. In women with surgical menopause, a moderate statistically significant correlation was observed only between menopause time and S index (r=-0.41, p=0.039). In premenopausal women, only testosterone correlated weakly with coefficient of variation, SDNN, PNN50, RMSSD, and power of HF band. In postmenopausal women, no correlations were found. We did not find any significant relationship between autonomic indices and hot flashes, assessed by hot flash diary.
  
  
  CONCLUSIONS
  We did not find a clinically important relationship between cardiovascular autonomic control and menopausal status in women.
authors: Department of Obstetrics and Gynecology, Saratov State Medical University, Saratov, Russia.
authors: Irina W
authors: IW
authors: Neufeld
authors: Centre of New Cardiological Informational Technologies, Research Institute of Cardiology, Saratov State Medical University n.a. V.I. Razumovsky, Saratov, Russia ; Department of Nano- and Biomedical Technologies, Saratov State University, Saratov, Russia.
authors: Anton R
authors: AR
authors: Kiselev
authors: Department of Nano- and Biomedical Technologies, Saratov State University, Saratov, Russia.
authors: Antoly S
authors: AS
authors: Karavaev
authors: Saratov Branch of the Institute of Radio Engineering and Electronics, Saratov, Russia.
authors: Mikhail D
authors: MD
authors: Prokhorov
authors: Centre of New Cardiological Informational Technologies, Research Institute of Cardiology, Saratov State Medical University n.a. V.I. Razumovsky, Saratov, Russia ; Department of Nano- and Biomedical Technologies, Saratov State University, Saratov, Russia.
authors: Vladimir I
authors: VI
authors: Gridnev
authors: Department of Nano- and Biomedical Technologies, Saratov State University, Saratov, Russia.
authors: Vladimir I
authors: VI
authors: Ponomarenko
authors: Department of Nano- and Biomedical Technologies, Saratov State University, Saratov, Russia.
authors: Boris P
authors: BP
authors: Bezruchko
keywords: 0.1-Hz rhythms; Autonomic control; heart rate variability; hot flashes; menopause; sex hormones